1 Some Untractable Classes of Constraint Networks

反义词主考词及答案归纳1．带“熟”标记的词为熟词僻义2．由于留题模考的缘故，本归纳不包括宋昊类比反义词31-35部分及02年11月，03年3月及06年6月的反义词。

单词出现频数反义词Abate 1 augmentAbdicate 1 assume (熟，担任)Aberrant 1 normalAbhor 1 greatly admireAbrogate 1 upholdAbscission 1 process of graftingAccelerate 1 retardAccessory 1 of primary importanceAccolade 1 criticismAccrete 1 wear awayAcquiesce 1 resistAccumulation 1 dissipationAdulteration 1 purificationAdvocate 1 denounceAerate 1 remove air fromAffable 1 irascibleAffiliation 1 dissociationAffinity 1 aversionAgape 1 closedAggregate 2 isolated units, disperseAlacrity 2 hesitance and reluctance, recalcitrance Alienate 1 reuniteAlleviate 1 exacerbateAllude 1 mention explicitlyAlly 1 adversaryAmalgamate 3 separate (两次), isolateAmeliorate 1 implementAmortize 1 suddenly increase one’s indebtedness Amplify 1 abridgeAnalogous 1 lacking similarityAnarchy 1 orderAnchor 1 dislodgeAnomalous (anomaly) 4 normal, conforming to anestablished rule,predicted occurrence,conformity to norms Antipathy 1 settled fondnessApocryphal (apocrypha) 2 authenticated, canonApologist 1 protagonistApposite 2 irrelevant, extraneous Appreciable 1 imperceptibleApprise 1 withhold informationApprobation 1 condemnationAppropriate (熟，盗用) 1 surrenderApt 1 extremely inappropriateArcane 1 well-knownArrest 1 vitalizeArrhythmic 1 exhibiting regularityArtifice 1 candorArtlessness 2 cunning, guileAscend 1 go downAseptic 1 contaminatedAspersions 2 flattery, glowing tributeAsperity 1 mildness of temperAsset 1 liability(债务)Assuage 1 intensifyAttenuate 1 strengthenAudacious 1 timidAuthentic 1 bogusAutonomy 1 dependenceA we 1 irreverenceAver 1 denyAvid 1 indifferentAxiomatic 1 controversialBackfire 1 produce an expected resultBadinage 1 serious conversationBaffle 1 enlightenBait 1 fortify (bait 引诱，fortify使人坚定不受引诱)Baleful 1 beneficentBalloon 1 decrease slowlyBanality (banal) 2 original expression, arresting Bankruptcy 1 solvencyBarb 1 complimentary remarkBawdy 1 decorousBegin 1 concludeBelie 1 averBellicose 1 pacificBeneficence 1 meannessBent(熟，天赋) 1 ineptitudeBifurcate 1 coalesceBlithe 1 graveBoisterous 1 quietBolster 2 undermine, decrease support of Bombastic (bombast) 2 understated, down-to-earth language Boon 1 misfortuneBoor 1 civil personBoycott 1 patronizeBreach 1 solderBrilliance 1 dullnessBroach 1 close offBucolic 1 urbanBulge 1 depressed regionBungle（把事做糟） 1 bring offBurgeon 2 subside，wither(以后也曾主考) Calcification 1 flexibilityCallow 1 behaving with adult sophistication Callousness (冷淡的，与callow区分) 1 sensitivity Canonical 1 heterodoxCapitulate 1 resistCapricious 1 steadfastCardinal 1 minorCareen 1 move steadilyCastigation 1 approbationCatalyze 1 inhibitCaustic 1 innocuousCede 1 refuse to yieldCelebrity 1 obscurityCensure 1 commendCessation 1 commencementChary 1 boldChampion 1 disparageChicanery 2 aboveboard action, honest dealing Chronic (熟，这里chronic取多发的意思) 1 sporadic Circumlocution 1 succinctnessCircumvention 1 direct encounterCivility 1 rudenessClinch(熟，使确信) 1 make more doubtful Coalesced (coalesce) 1 broken apart, desegregateCoda 1 preludeCollect 1 scatterComeliness 1 unattractivenessCommodious 1 crampedCommotion 1 tranquilityComplaisance 1 churlishnessCompound 1 separateConcatenate 1 separateConcord 1 dissensionConcur 1 dissentConfound 1 discriminate betweenControl (熟，实验对照组) 1 group experimented on(被分组实验) Consider 1 table (搁置)Consolidation 1 fragmentationConstrain 1 releaseConstrict 1 dilateContaminated 1 purifyContinuity 1 disjunctionContumacious 1 tractableConvene 1 dissolveConversance 1 lack of familiarityConvoke 1 adjournConvoluted 1 straightforwardCorporeal 1 intangibleCorroboration (corroborate) 3 lessening of certainty, controvert, denyCorrugated 1 smoothCountenance 3 regard with disfavor, forbid, condemn Covert 1 openCowed 1 undauntedCower 1 brazenly confrontCozen 1 deal with forthrightlyCrass 1 refinedCraven 1 valorousCryptic 1 self-explanatoryCumbersome 1 easy to handleCurmudgeon 1 agreeable personCursory 2 slow and thorough, painstakingly thorough Curtail 1 prolongDab 1 coat thoroughlyDampened (dampen) 2 amplified, enlivenDashing 1 bumpkinlyDated 1 currentDebauchery 1 asceticismDebacle 1 complete successDebonair (温文而雅的) 1 uncouthDebut 1 farewell performanceDecadence (decadent) 2 wholesomeness (wholesome) Decorous 1 unseemlyDefault 1 fulfill and obligationDeference 1 contemptDefiance 1 submissionDeft 1 awkwardDehydrate 1 saturate with waterDelicacy 1 crudityDemotion 1 elevationDenial 1 avowalDenuciation 1 eulogyDeracinate 1 plantDeride 1 show respect forDerivative 1 innovativeDependable 1 fickleDeposition 1 process of erodingDesiccate 2 hydrate, add water toDesultory 2 carefully planned, strictly methodical Detritus 1 valuable productDiatribe 3 encomium(做过主考词), eulogy, laudatory piece of writing Diffident 1 boldDilapidated 1 restoredDisgorge 1 ingestDissemble 1 behave honestlyDin 2 silence, hushDisabuse 2 lead into error （两次）Disaffect 1 win overDisarm 1 put on guardDischarge 1 hireDiscrete 1 continuousDisdain 1 treat favorablyDisgorge 1 swallowDisinter 1 buryDisingenuousness 1 guilelessnessDismay 1 encourageDisparate 1 homogeneousDispatch 1 leisurelinessDisposed 1 disinclinedDispute 1 acceptDissembling 2 candid (两次选项相同) Dissonance 1 concordDistend (distension) 1 constrict, compressionDiurnal 3 chiefly active at night, occurring at night, nocturnal Diverge (divergence) 1 come together, unification Diversity 1 uniformityDivest 1 endowDivestiture 1 acquisitionDivulge 1 keep secretDoff 1 donDogma 1 heresyDominant 1 recessiveDominate 1 have no control overDormancy 1 activityDwindle 1 increaseEbullience 2 calm restraint, impassiveness Effrontery 2 decorum, timidityEgress 1 entranceElaborate 1 simplifyElasticity 1 lack of resilience Emaciation (emaciate) 1 invigoration, fatten Embolden 1 cowEmboss 1 flatten outEmit 1 absorbEmploy 1 leave idle (个人认为的答案) Encomium 1 harsh criticismEndemic 1 exoticEndorse 1 oppose publiclyEnervate 2 strengthen, fortifyEngender 1 eradicateEnnui 2 excitement, exuberanceEnrich 1 depleteEnsconce 1 displaceEnsemble 1 soloEpicure 1 a person indifferent to food Equable 1 intemperateEquanimity 1 agitationEquity 1 unfairnessErode 1 depositErudite (erudition) 2 unlettered, ignoranceEschew 1 seekEsoteric 1 generally knownEstimable 1 infamousEstrangement 2 reconciliation, rapprochementEtch 1 effaceEulogy 1 defamationExact(熟，强求) 1 forgiveExactitude 1 imprecisionExcavate 1 fill inExcessive 1 too little(inexorable, exorable 可说服的) 1 relentingExcoriate 1 praise lavishlyExcrete 1 ingestExculpate 1 indictExhaustive 2 incomplete, partialExhilarate 1 saddenExigent 1 deferrableExonerate 1 prove guilty, inculpateExotic 1 indigenousExpend 1 store upExpire 1 come to lifeExtant 1 extinctExtemporaneous (extemporize) 2 planned, follow a script Extenuating 1 aggravatingExtinguish 1 igniteExtraneous 1 relevantExude 1 absorbExultation 1 state of griefEvacuate 1 fill upEvanescent 1 permanentEvince 1 keep hiddenFabulous 1 mundaneFacilitate 2 hamper, thwartFacetious (爱开玩笑的) 2 lugubrious, earnestFactional 1 disinterestedFair-minded 1 partisanFallacious (fallacy) 2 valid, valid argument, valid reasoning Fallow 1 in useFatuousness (fatuity) 2 sensibleness, sagacityFeigned 1 genuineFeral 1 cultivatedFerment 1 tranquilityFerrous 1 containing no ironFervor 1 apathyFetid 1 having a pleasant smellFetter 1 set freeFiasco 1 a notable successFictitious 1 authenticFinesse 2 heavy-handedness, ineptitudeFlag(熟，衰退) 1 waxFlamboyant 1 subduedFledgling (fledge) 2 experienced practitioner, molt(脱羽毛，原意) Flippant 1 earnestFlounder 1 act gracefullyFlourish 1 lack of embellishmentFluctuate 1 remain steadyFluent 1 haltingFluke 1 expected occurrenceFlustered 1 calmFocus 2 diffuse, disperseFoment 2 squelch, stifleForestall 2 precipitate, abetFracas 2 peaceful situation, peaceable discussion Frequent (frequency) 2 visit rarely, rarityFriable 2 not easily crumbled (两次都是这个) Fringe 1 centerFrustrate 1 abetFulmination 1 praiseFumble 1 handle adroitlyGainsay 2 speak in support of, concur Gambol 1 plodGargantuan 1 minusculeGarrulity 1 taciturnityGaucheness 1 polishGenial 1 dyspepticGermane 2 inappropriate, irrelevantGild (熟，矫饰与glib区别) 1 represent accuratelyGist 2 tangential point, trivial pointGlib 2 labored(熟，费力的说或做), awkward Goad 1 lullGossamer 1 ponderousGrandiloquent 1 secretiveGrate 1 sootheGratuitous 2 warranted (两次选项相同) Grievous 1 slightGrit (熟，勇气) 1 spinelessnessGrounded 1 aloftGroup 1 isolateGrouse 1 rejoiceHackneyed 2 original, freshHarmonious 1 discordHalcyon 2 miserable, tempestuousHallmark 2 uncharacteristic, uncharacteristic feature Hapless 1 fortunateHarangue 1 speak temperatelyHarbor 1 evictHarrow 1 assuageHaven 1 dangerous placeHavoc 1 serenityHeavy-handed 1 deftHeckle 1 support verballyHegemony 1 lack of authorityHoodwink 1 disabuseHubris 1 humilityHull 1 kernelHyperbole 1 understatementIdyll 1 experience fraught with tension Ignominious 1 honorableImmediate 1 futureImmune 1 having no resistImpassive 1 overwroughtImpecunious 1 affluentImpede 1 assistImpel 1 restrainImpetuous 1 deliberate(深思熟虑)Impermeable 1 porousImplosion 1 rapid outward movementImprobity 1 honestyImpromptu 1 carefully rehearsedImpudent 1 respectfulImpugn 2 champion (熟，支持，曾主考。

NO(2)-NO(3)NO(2)-1INCENTIVE:deterrent COMPASSION:indifference AGGRAVATE:alleviate IMPLAUSIBLE:believable ANTIPATHY:benevolence EXTRICATE:entangle MORDANT:genialGLUT:dearthDISCRETE:continuous PROPITIATE:arouse hostility ENFRANCHISE:unfetter SLUR:pronounce clearly MUTE:amplifySTIGMA:mark of esteem ANHYDROUS:wet VACILLATE:resolve firmly EVANESCENT:lasting EBULLIENCE:impassivityRAREFACTION:condensation RECALCITRANT:submissive IMBROGLIO:harmonyFORMENT:inhibitNO(2)-2SUBTLE:obviousABOMINATE:esteem OSCILLATION:absence of variation EXTRICATE:enmeshCAPRICIOUS:resoluteSUNDER:linkTORPOR:extreme excitability AUSPICIOUS:ill-omened VOLATILE:stableSPATE:trickling flow FACTIOUS:cooperative NEGLIGENCE:careGRUELING:effortlessLEVITY:seriousnessAGITATE:sootheACERBIC:sweetFLIT:plodINVECTIVE:laudatory speech STAID:jaunty PROSCRIBE:permitSCAD:paucity EVANESCENT:perpetualNO(2)-3OMIT:include VERSATILE:unchangeable ASSISTANCE:interference SUTURE:incision POSTULATE:deny as false DERELICT:extremely careful SOPORIFIC:invigorating ENSCONCE:unsettle CLOUT:impuissance INGENUOUS:awkwardBRUIT:keep secret BARRICADE:permit passage TAUT:loose or uniform OPPORTUNE:inconvenient DISMAY:heartenFESTER:healDISCERNMENT:lack of insight DEPLOY:concentrate MOLLIFICATION:inflammation INFELICITY:appropriateness ASPERITY:mildness DESULTORY:assiduousNO(3)-1ABBREVIATE:extend REFUTABLE:indisputable OSCILIATE:remain static EXODUS:influxREPROBATE:righteous individual PIQUANCY:blandness CAPITULATION:resistance DESICCATE:drenchHERMETIC:easily comprehended DAUNT:make resolute EQUANIMITY:excitability NOMADIC:settledMUTE:amplifyTEDIOUS:stimulating JUDICIOUS:unwiseMOTILITY:stasisMUNIFICENCE:stinginess PROPONENT:detractorABDICATE:usurpABEYANCE:fulfillment DISSEMINATE:garnerSATURNINE:genialNO(3)-2VULNERABLE:safeDECREPIT:sturdyBALM:irritantINSOLVENCY:ability to pay one's debts HONE:bluntSINUOUS:directEVINCE:concealEPHEMERAL:enduringINSALUBRITY:healthfulness TRUCULENCE:benevolenceTURPITUDE:probityEXAGGERATE:minimize INCARCERATE:liberateCAUTIOUS:rashVACILLATE:stand firm ANALGESIA:sensitivity to pain VACUITY:plenitudeINVECTIVE:laudatory words FASTIDIOUS:indiscriminate UNTOWARD:favorableBROOK:refuse to tolerate PILLORY:exaltNO(3)-3DETERIORATION:improvement RETARD:speed upPRISTINE:corrupted by civilization ENIGMATIC:free of ambiguity FERVID:restrainedASCETICISM:indulgence MELLIFLUOUS:cacophonous CALUMINATE:vindicateCONFORM:not hew toSLOTH:industryOSSIFY:transcend conventions QUOTA:unlimited number SEGMENT:make wholeIMMUNITY:susceptibility DISJOINTED:orderlyBANE:blessingACCOLADE:disapprobationPLUMB:horizontalPALLIATE:increase the intensity of RAVEL:knitGOAD:curbEFFLUVIA:desired productsNO(4)-1COMMOTION:tranquillity INDETERMINATE:definite DIVERGE:encloseFLIPPANT:earnestNEXUS:disconnected components LEVY:rescindANOMALOUS:normalGROUSE:rejoiceGIST:tangential point EFFRONTERY:decorumLIMPID:turbidSTABILIZE:fluctuateRENOVATE:cause to decayPROFUSE:scantANCHOR:dislodgeREFUTE:proveNADIR:topmost point APPROBATION:condemnation FATUOUSNESS:sensibleness TIMOROUS:intrepidSEMINAL:hampering further development DISINGENUOUSNESS:guilelessnessNO(4)-2BOISTEROUS:quietEMIT:absorbMETAMORPHOSE:remain unalteredALLY:adversaryOFFHAND:premeditatedBROACH:close offGIST:trivial pointDIVESTITURE:acquisitionEXTANT:extinctTRACTABILITY:incorrigibility NOISOME:attractively fragrantPERSEVERE:give upWATERPROOF:permeableAMALGAMATE:separatePUNGENCY:blandnessANARCHY:orderINCURSION:retreatABROGATE:upholdHAPLESS:fortunateAVER:denySEDULOUS:carelessINSULARITY:cosmopolitanismNO(4)-3FLUSTERED:calmENDORSE:opposepubliclyEXPIRE:come to lifeINDELIBILITY:erasability METAMORPHOSIS:continuation without change MOROSE:cheerfulSPIRITUAL:corporealDISPATCH:leisurelinessFERMENT:tranquillityFACETIOUS:lugubriousCRAVEN:valorousACCELERATE:retardJABBER:speak slowly WARMONGER:pacifistFLUENT:haltingDISSONANCE:concordSAVANT:unlearned person BREACH:solderTORTUOUS:straightforward PLETHORA:dearthPOSTURE:behave naturally GOSSAMER:ponderousNO(5)-1LAG:forge aheadRANDOMIZE:systematize SURCHARGE:discount SYNCHRONOUS:out-of-phase PROFUSE:scantyINERTIA:tendency to change motion DIN:silenceGAUCHENESS:polishINCHOATE:completely formedENDEMIC:exoticREDOUBTABLE:unimpressive BRILLIANCE:dullnessQUANDARY:state of complete certainty AGGREGATE:isolated units SUBSTANTIATION:disproof IMPUDENT:respectfulRECANT:affirmDIVEST:endowBANALITY:original expression UBIQUITOUS:uniqueESCHEW:seekBELIE:averNO(5)-2COLLECT:scatterSERRATED:without notches FLEDGING:experienced practitioner SUPPOSITION:certaintyABERRANT:normalOBDURATE:flexibleLIST:be uprightFORESTALL:precipitateTENDENTIOUS:unbiased REDUNDANT:economicalRUE:satisfaction PARTITION:unifyABHOR:greatly admire TAINTED:wholesome CARDINAL:minor ESTRANGEMENT:reconciliation ABATE:augmentDOFF:donERUDITE:unlettered GARRULITY:taciturnity SCOTCH:encourage LIBERTINE:asceticNO(5)-3EVACUATE:fillup OUTLANDISH:conventional INHIBITOR:catalyst CONSTRICT:dilate REPORTORIAL:imaginative INDIGENCE:wealth INVEIGLE:request directlyTRACTABLE:headstrong INCHOATE:fully formed PERFIDY:loyalty APPROPRIATE:surrender BEGIN:concludeSHUN:seek activelyEQUITY:unfairness PROPAGATION:extirpation PRESUMPTUOUS:humble VACILLATION:motionless balance PENCHANT:dislikeSOMATIC:nonphysical CONFOUND:discriminate between CHARY:boldFLAG:waxNO(6)-1INFINITY:bounded space TRUCE:resumed fighting DAMPED:amplified TURBULENT:pacificLUCID:vagueEBULLIENCE:calm restraintCAPRICIOUS:steadfast IMPASSIVE:overwrought TORTUOUS:directTOUT:cast aspersion on PROMPT:checkPRESS:withdraw INNOCENCE:guilt ELABORATE:simplify PERSISTENCE:inconstancy SKEPTICISM:conviction REACTANT:inert material CODA:prelude HACKNEYED:original MACERATE:harden by drying GLIB:laboredIMPUGN:championNO(6)-2EXCESSIVE:too little VICTOR:loser AUDACIOUS:timid AUTONOMY:dependence EXTEMPORANEOUS:plannedDISTEND:constrict ASSUAGE:intensifyCLINCH:make more doubtful PROFLIGACY:frugality PUISSANCE:powerlessness RAVE:panCONTAMINATE:purifyFOCUS:diffuseUNDERMINE:reinforceFLUKE:expected occurrence PREEN:rumpleDIN:hushQUIESCENCE:restless activity OBDURATE:complaisant SALUBRIOUS:unhealthy BALEFUL:beneficent VERDANT:sereNO(6)-3TURBULENCE:tranquillity DEHYDRATE:saturate with water LOLL:move vigorously INTREPID:apprehensivePRECURSORY:derivative PERENNIAL:fleetingDISPARATE:homogeneous FULMINATION:praiseEBULLIENCE:impassiveness PREDILECTION:propensity to dislike BANAL:arrestingDOMINATE:have no control over SIDESTEP:confront directly FACILITATE:hamperMUNDANE:exoticELASTICITY:lack of resilience APPRISE:withhold information SQUALID:pristine MANIPULATIVE:guileless ANTIPATHY:settled fondness FLEDGE:moltDIATRIBE:encomiumNO(7)-NO(9)NO(7)-1ASCEND:go downPOROUS:impermeableAFFILIATION:dissociation INADVERTENCE:careful attention BOLSTER:undermine CATALYZE:inhibitWAFFLE:speak unequivocally DISCRETE:continuous LACONIC:garrulous DECOROUS:unseemly INCIPIENT:full-blown ASEPTIC:contaminated QUIESCENCE:actionLUMBER:glideNUCLEATE:scatterLEVITY:gravity DENUNCIATION:eulogy TREACHEROUSNESS:faithfulness SOPORIFIC:stimulantSTYMIE:fosterMUNDANE:unearthlyWELTER:orderly arrangementNO(7)-2GROUP:isolateIMMEDIATE:future PERSEVERANCE:cessation of effort OFF-KEY:at the proper pitch BOLSTER:decrease support of DEBACLE:complete success ALLEVIATE:exacerbate ARTLESSNESS:originality LABILE:stableNUGATORY:consequentialBENT:ineptitudeEXTINGUISH:igniteDWINDLE:increaseUNEARTH:concealTESTINESS:patience PRECARIOUS:firmly grounded FETID:having a pleasant smell PREJUDICED:disinterested TRAVESTY:paragonPROSCRIBE:sanction TRUCULENT:gentleIMPROBITY:honestyNO(7)-3VAGUE:well definedFOCUS:dispersePROLOGUE:epilogueDISARM:put on guardINFLATE:minimizeINDIGENOUS:acquiredQUELL:fermentEGRESS:entrancePIED:solid-coloredGAINSAY:speak in support of COMPLAISANCE:churlishness ASSET:liabilityCONCUR:dissentAMALGAMATE:isolateFERROUS:containing no iron PHLEGMATIC:vivacious PRODIGIOUS:slight CORROBORATION:lesseningofcertainty PALPABILITY:intangibility ALACRITY:hesitance and reluctance MANNERED:naturalDISSEMBLE:behave honestlyNO(8)-1FREQUENT:visitrarely COMPOUND:separateCRASS:refinedPLASTICITY:rigidityCONVOKE:adjournCOMMODIOUS:cramped CORROBORATE:controvert MACULATED:unspottedESOTERIC:generally known FRUSTRATE:abetASPERSIONS:flatteryORIENT:confuse UNIMPEACHABLE:open to question MEANDER:move purposively EXPEND:store upSEAMY:decent and respectable LUCID:murkyLASSITUDE:a feeling of vigor HALLMARK:uncharacteristic feature DIATRIBE:eulogySEDULITY:lack of industriousnessAPPOSITE:irrelevantNO(8)-2CONSTRAIN:releaseSQUAT:tall and thin OPAQUENESS:clarity COMELINESS:unattractiveness PROFUNDITY:superficiality BURGEON:subsideSINEWY:weak EXHAUSTIVE:incomplete PINE:becomein vigorated OBSTINACY:persuasiveness EXACT:forgiveINSTINCT:learned response SENSATION:unnoticed event TRANQUILITY:pandemonium PLASTICITY:rigidityRIFT:reconciliation DESICCATE:hydrate ERUDITION:ignorance AFFABLE:irascible APOCRYPHAL:authenticatedRECALCITRANT:amenableHALCYON:miserableNO(8)-3CONSOLIDATION:fragmentationSECURE:unfastenFRACAS:peaceful situationGRATE:sootheHYPERBOLE:understatementINERRANCY:fallibilitySTEEP:parchRECUMBENT:standing upNATTY:sloppyEXIGENT:deferrablePLATITUDE:original observationPEER:a subordinate person SYNCHRONOUS:occurring at different times ALIENATE:reunitePREDESTINE:leave to chanceAERATE:remove air fromFALLOW:in useCORROBORATE:denyPERFUSE:glanceatSEEMLY:indecorousTENUOUS:substantialGRATUITOUS:warrantedNO(9)-1MUTTER:speak distinctlyTRANSPARENT:opaqueENSEMBLE:soloRETAIN:discardRADIATE:absorbEPICURE:a person indifferent to food PREVARICATION:veracityAMORTIZE:suddenly increase one's indebtedness EMACIATION:invigorationUNALLOYED:adulteratedMINATORY:reassuringFLUCTUATE:remain steadyPRECARIOUS:safeFUMBLE:handle adroitlyAUTHENTIC:bogusCOWER:brazenly confrontPRISTINE:contaminatedLAMBASTE:extolVISCID:slickTURPITUDE:saintly behavior PHILISTINE:aestheteODIUM:infatuationNO(9)-2DOMINANT:recessiveDISPUTE:acceptPERJURE:truthful deposition DORMANCY:activityPLETHORA:scarcitySTOCK:uniqueBURGEON:witherOCCULT:bareNASCENT:fully established AMPLIFY:abridgeEXTENUATING:aggravating OVERREACH:aim below one's potential BULGE:depressed region FACILITATE:thwartEULOGY:defamationFRACAS:peaceable discussion HARROW:assuageBOOR:civilpersonHACKNEYED:freshSODDEN:desiccatedGAINSAY:concurNICE:impreciseNO(9)-3STERILIZE:contaminate INADVERTENT:intentional SUBLIMINAL:at a perceptible level PLACATE:antagonizeINUNDATE:drainFLOURISH:lack of embellishment SUMMARILY:after long deliberation STOLID:excitableIDYLL:experience fraught with tension ASPERITY:mildness of temper DESULTORY:strictly methodical PERISH:surviveUNPREDICTABLE:dependableTRIBUTE:denunciationFINESSE:heavy-handednessSAP:bolsterCONVOLUTED:straight forward MITIGATE:exacerbateTORPOR:vigorZENITH:nadirVENAL:incorruptible PERIPATETIC:stationaryNO(9)-4HARMONY:discordSLACK:tautJOCULAR:seriousIMPEDE:assistSAP:fortifyCONTROL:group experimented on RECONDITE:widely understood INIMITABLE:ordinaryDISINTER:buryDIATRIBE:laudatory piece of writing HOODWINK:disabuseINSERT:removeBANKRUPTCY:solvencyRELEVANT:immaterialIMPLOSION:rapid outward movementSLAB:sliverRAREFY:make dense IMPETUOUS:deliberate VITUPERATIVE:complimentary FOMENT:squelch INCHOATE:explicitTYRO:expertNO(9)-5TOY:think over seriously QUACK:honest practitioner FRINGE:center FALLACIOUS:valid CRYPTIC:self-explanatory RENT:made whole CONSIDER:table TENUOUS:substantial MERCURIAL:constant OPPROBRIUM:good repute VENERATION:derision SEND:receive INTERLOCKING:independent REFLECT:absorbLACKLUSTER:radiantZENITH:lowest pointENGENDER:eradicateGRIEVOUS:slightANOMALOUS:conforming to an established rule PRECIPITATE:deliberatePROLIXITY:extreme brevityDISABUSE:lead into errorNO(9)-6LIMP:firmGLOBAL:localSTABILITY:inconstancyDILATE:narrowCONSOLE:aggravate griefEXCULPATE:attribute guiltACCRETION:reduction in substance caused by erosion CADGE:earnABJURE:espouseSPECIOUS:validQUOTIDIAN:extraordinaryADHERE:detachUNCONVENTIONALITY:fidelity to customPINCH:abundant amountOUTSET:termination RAREFY:mak emore dense EFFRONTERY:deference SCURVY:above reproach OBDURATE:complaisantAVER:denyPITH:superficial element SUPINE:vigilantSHALLOW:profoundIMMUNE:having no resistance PROPAGATE:fail to multiply LULL:increased activity PERPETUAL:intermittent ACCOLADE:criticism GAMBOL:plodREFUTATION:verification REQUITE:leave unrepaid REVERE:profaneMOLLIFY:ireIMPROMPTU:carefully rehearsedBALLOON:decrease slowly AVID:indifferentMOROSE:lighthearted ANOMALY:predicted occurrence NEOLOGISM:archaism RAREFY:condenseCAUSTIC:innocuous SOLVENT:precipitant ESTIMABLE:infamous PRODIGALITY:penury90(10)FALLACY:valid argument DIVULGE:keep secret BOYCOTT:patronize ADULTERATION:purification DEPOSITION:process of eroding ENERVATE:strengthen LOQUACIOUS:taciturn REPINE:express joy VENERATION:derision INVETERATE:casual UNDERMINE:undergirdPERTAIN:be irrelevant FREQUENCY:rarityAMALGAMATE:separate ARRHYTHMIC:exhibiting regularity BLITHE:gravePOLEMICAL:conciliatory PRECIPITATE:deliberate DEFERENCE:contemptUNTOWARD:favorable and anticipated OPPROBRIOUS:irreproachable VERITABLE:specious91(2)ADVOCATE:denounce CORRUGATED:smoothCOVERT:openEXTRANEOUS:relevant DISTENSION:compression CONVERSANCE:lack of familiarity EMBOSS:flatten outQUOTIDIAN:unusualTORRIDNESS:frigidity OPPROBRIUM:good reputeDISABUSE:lead into error MINIMIZE:overestimate VARIATION:uniformity DEFAULT:pay one's debts SUBSTANTIVE:trivial METEORIC:gradualCENSURE:commendINCHOATE:fully realized APOCRYPHA:canonABSCISSION:process of grafting EQUANIMITY:agitation ONEROUS:requiring little effort 91(4)REPULSION:attraction ANALOGOUS:lacking similarity CESSATION:commencement SPLENDOR:squalorDERIDE:show respect for SPARSE:rifeTIRADE:dispassionate speech DIFFIDENT:boldSENTIENT:unconsciousATTENUATE:strengthen SURFEIT:famish DILUTE:concentrate FERVOR:apathy EMACIATE:fatten BOMBASTIC:understa。

带有饱和的电机伺服系统非奇异终端滑模funnel控制陈强;汤筱晴【摘要】本文提出一种非奇异终端滑模funnel控制(NTSMFC)方法,实现带有饱和输入电机伺服系统的指定性能跟踪控制.根据中值定理,非光滑饱和函数转化为放射形式,并且应用一个简单的神经网络进行逼近和补偿.为保证跟踪误差被限制在指定的界限内,同时为避免构建复杂的barrier李雅普诺夫函数或逆函数,本文采用一个新的限制变量.然后,构建非奇异终端滑模funnel控制器保证电机伺服系统的指定跟踪性能.该方法无需事先已知输入饱和函数的界限等先验知识,且基于李雅普诺夫函数设计可以保证位置跟踪误差的收敛性,最后给出仿真对比实例证明了该方法的有效性.【期刊名称】《控制理论与应用》【年(卷),期】2015(032)008【总页数】8页(P1064-1071)【关键词】funnel控制;非奇异终端滑模;神经网络;输入饱和【作者】陈强;汤筱晴【作者单位】浙江工业大学信息工程学院,浙江杭州310023;浙江工业大学信息工程学院,浙江杭州310023【正文语种】中文【中图分类】TP273Over the past decades，motor servo systems have been widely studied in motion control applications［1-3］.The mechanical connection between servo motors and mechanical devices produces non-smooth nonlinear constraints on their outputs and/or inputs in the form of the physical stoppage，saturation，hysteresis，and dead-zone.During operation，violation of the constraints leads to performance degradation，hazards or system damage.For the output constraint，there are some effective methods for position，velocity，and force constraints existing in motor servo systems.By using the logarithmic function in the Lyapunov function design，a barrier Lyapunov function（BLF）is constructed，in which a symmetric or asymmetric constraint is utilized to constrain the state variable of the control system，so that the tracking errors can be indirectly constrained［4-6］.However，the expression of BLF is complex， and extra efforts are needed to ensure the continuity and differentiability.In［7-9］，a prescribed performance control（PPC）scheme is proposed，and the tracking error of a nonlinear system is transformed into a new error by constructing the inverse of the transformation function.Therefore，the prescribed tracking performance of the transient property and the steady-state error can be guaranteed.But PPC scheme may cause a singularity problem since the inverse transformation function includes a partial differential terms.Being a non-model-based（memory less）constraint technique，the funnel control is proposed to guarantee the prescribed transient behavior and asymptotic tracking of the system［10-13］.This technique bypassesthe difficulties of identification and estimation of traditional high-gain adaptive control.Recently，a new error-constraint variable is designed as a virtual control variable in the backstep-ping design to ensure the prescribed transient and steadystate performance［14］，and thus the aforementioned complex transformation function is not needed any more.In［15］，a funnel dynamic surface control with prescribed performance is proposed to overcome the explosion of complexity problem in the backstepping technique，and the tracking performance of closed-loop system is guaranteed.Sliding mode control（SMC）is one of the most useful approaches to deal with system uncertainties and bounded disturbances，and has been widely applied in various fields［16-17］.The traditional linear sliding mode control scheme can guarantee the asymptotical convergence of tracking errors when time goes to the infinity.Recently，many research works have focused on the finite-time convergence of tracking errors.Man and Yu［18］proposed a terminal sliding mode control（TSMC）scheme by introducing a nonlinear term in the SMC design and the tracking error can be guaranteed to converge within a finite time.However，there are two disadvantages of TSMC，i.e.，the singularity problem and requirement of the uncertainty bound.To overcome the singularity problem，Feng，et al.［19］and Yu，et al.［20］proposed nonsingular terminal sliding mode control（NTSMC）methods.Besides，Chen，et al ［21］utilized a recurrent Hermite neural network（RHNN）to estimate the lumped uncertainty online when designing the nonsingular terminalsliding surface，and hence the lumped uncertainty bound is unnecessary. As one of the most important non-smooth nonlinearities，saturation on hardware dictates that the magnitude of the control signal is always constrained，which often severely limits system performance，giving rise to undesirable inaccuracy or leading instability［22］.So far，many significant results on the control design for the systems with input saturation have been obtained［23-27］.However，the lower and upper limits of the saturation constraints should be exactly known or estimated for controllers design.Recently，several research work has been investigated without using the prior knowledge of saturation bounds. Wen et al.［28］uses a smooth non-affine function of the control input signal to approximate the non-smooth saturation function，and a Nussbaum function is introduced to compensate for the nonlinear term arising from the input saturation.Based on the idea of［28］，Wang et al.［29］transforms the non-affine function of the system into an affine form，and an adaptive control scheme is derived without requiring the prior knowledge of input saturation bounds.In this paper，we propose a nonsingular terminal sliding mode funnel control to achieve a prescribed tracking performance for motor servo systems with unknown input saturation.A smooth and affine function is used to solve the input saturation problem.Meanwhile，to avoid using the complex barrier Lyapunov function or inverse transformed function，a funnel constraint variable is utilized in constructingthenonsingularterminalslidingmodescheme to force thetracking error fall within prescribe boundaries. No prior knowledge of the input saturation bounds is required in the proposed method，and the effectiveness is demonstrated by simulation results.2.1 System descriptionThe mechanical dynamics of the motor servo system can be described as follows:where x=［x，］T∈R2，u（t）∈R，y∈R are state variables，the control input voltage to the motor and the output from the motor，respectively；x is the position，m is the inertia，k0is a positive control gain（the force constant），f（x，t）is the friction force；d（x，t）represents a bounded disturbance modeling nonlinear elastic forces generated by coupling and protective covers，measurement noise，power electronics disturbances and other uncertainties.v（u）∈R is the plant input subject to saturation nonlinearity described bywhere vmaxis an unknown parameter of input saturation.For convenience of the controller design，defining x1=x，x2=，the mechanical dynamics of the motor servo system can be transformed into Without loss of generality，two technical assumptions are made to pose the problem in a tractable manner.1）The desired position trajectory yd，the time derivative˙ydand¨ydare both bounded and smooth signals.2）The angular position and velocity，x1and x2，are measurable.2.2 Nonlinear saturation modelClearly，the relationship between the applied control v（t）and thecontrol input u（t）has a sharp corner when |u（t）|=vmax.As shown in Fig.1，the saturation is approximated by a smooth non-affine function defined asThen，v=sat（u）in（2）can be expressed in the following formwhere d1（u）=sat（u）-g（u）is a bounded function and its bound can be obtained aswhere D is the upper bound of|d1（u）|.According to the mean-value theorem［29］，there exists a constant ξ with 0＜ξ＜1，such thatwhereand u0∈［0，u］.By choosing u0=0，（6）can be rewritten in the following affine formSubstituting（7）and（5）into（3），we can obtainwhere2.3 Neural network approximationDue to good capabilities in function approximation，neural networks （NNs）are usually used for the approximation of nonlinear functions.The following neural network with a simple structure and a fast convergence property will be used to approximate the continuous functionwhere W∗∈Rn1×n2is the ideal weight matrix，φ（X）∈Rn1×1is the basis function of the neural network，ε is the neural network approximation error satisfying|ε|≤εN，φ（X）can be chosen as the commonly used sigmoid function，which is in the following formwith a，b，c and d being appropriate parameters.Remark 1 The employed neural network with sigmoid function representsa class of linearly parameterized approximation methods，and can be replaced by any other approximation approaches such as spline functions，RBF functions or fuzzy systems.However，the structure of the employed neural network in the this paper is simpler than the other neural networks that are commonly used in other works.There is no hidden layer in the employed NN，in which five inputs and one output are included and the corresponding weight matrix is 5×1.3.1 Funnel error variableFunnel control is a strategy that employs a timevarying gain ρ（t）to control systems of class S with a relative degree r=1 or 2，stable zero dynamics，and known high-frequency gains.The system S is governed by the funnel controller with the control inputwhere e（t）=y1-ydis the tracking error，ρ（·）denotes the control gain. As shown in Fig.2，evaluate the vertical distance at the actual time between the funnel boundary Fφ（t）and the Eucli dian error norm‖e （t）‖asThe funnel boundary is given by the reciprocal of an arbitrarily chosen bounded，continuous and positive function φ（t）＞0 for all t≥0 with＜∞.The funnel is defined asTo ensure that the error e（t）evolves inside the funnel Fφ（t），theexp ression of ρ（·）can be chosen asFrom（12）we can see that，when the gain ρ（t）increases，the error e （t）approaches the boundary Fφ，and when the gain ρ（t）decreases conversely，the error e（t）becomes small.A proper funnel boundary toprescribe the performance is selected aswhere δ0≥δ∞＞0，inf Fφ（t），and|e（0）|＜Fφ（0）.According to（11）and（12），define a new funnel error variable s1（t）aswhere the funnel boundary Fφ（t）satisfies the condition given in （13）.This variable will be employed to ensure the prescribed output performance.The derivative of（14）iswhereandwhere3.2 Controller designConsidering（15）and（16），the sliding mode manifold is designed as where α＞0.Differentiating s2，we haveSubstituting（8）and（16）into（18）yieldswhere the nonlinear function κ isSince κ is not ea sy to be exactly known，the modelbased controllers cannot be applied directly.Hence，we adopt a neural network（9）to approximate the nonlinear function κ.Assume that there exists a constant ideal weight matrix W∗so that the nonlinear function κ can be expres sed aswhere the input vectorIn the following，a nonsingular terminal sliding mode neural funnel control approach is developed for tracking control of the motor servo system（8）.To force s2converge to zero within a finite time，thenonsingular terminal sliding mode manifold is employed aswhere β＞0，p and q are positive odd integers with p＜q.Substituting（19）into（21）and using（20），the controller is designed aswhere b0is the lower bound of b；p and q are positive odd integers with p ＜q；is the estimate of the ideal weight W∗andµis the upper bound of sum of the neural network approximation error ε andTφ（X），where=W-is the weight estimation error of the neural network.The adaptive law ofis given bywhere K is a positive definite and diagonal matrix，and ν is a positiv e constant.Substituting（22）into（19）yieldsIn this section，a lemma and a theorem is provided to show the boundedness of all signals and the stability of the system（8）inboththereachingphaseandtheslidingphase，respectively.Lemma 1 Assume that there exists a continuous positive definite function V（t）satisfying the following inequality:where n＞0，0＜γ＜1 are constants.Then，for any given t0，V（t）satisfies the following inequality:andwith tsgiven byTheorem 1 Consider the motor servo system（8）with unknown nonlinear saturation（2），nonsingular terminal sliding manifold（21），control law（22），and weight update law（23），then1）All signals of the closed-loop system are bounded.2）The nonsingular terminal sliding manifold s2can converge to zero in finite time by using controllers（22），if the design parameterµ＞εN+‖Tφ（X）‖F.3）The tracking error e will fall into proscribed boundaries.Proof 1）Choose the following Lyapunov function candidatewhere km=FφΦF＞0.Differentiating（26）with respect to time and using（24），we have Substituting（23）into（27）yieldsInequality（27）implies that both s2andare bounded.Meanwhile，considering（17）and the boundedness of W∗，we can conclude s1，˙s1，andare bounded，and thus from（22）and（14），we can obtain u，e andare all bounded.Furthermore，the boundedness of yd，˙ydand¨ydcan lead to the boundedness of s2according to（17）.As a result，and˙s2is bounded due to the boundedness of guξ. Therefore，all signals of the closed loop system are bounded.From（26）-（28），the stability of the system（8）with control laws（22）and weight update law（23）has been proved.However，it is not necessary for the terminal sliding manifold s2to converge to zero in finite time.Therefore，further proof should be given to guarantee that the terminalslidingmanifolds2convergetozeroin finitetime.2）From（29），we can see that the sigmoid function φ（X）is boundedby 0＜φi（X）＜n0，i=1，···，n1， with n0=maxTherefore，φ（X） is bounded bywhere‖·‖denotestheEuclideannormofavector，φ（X）=［φ1（X）φ2（X）···φn1（X）］T.From the property of Forensics norm，it can be obtained thatSelect another Lyapunov function candidateDifferentiating（29）with respect to time and using（24），we have Sinceµ＞εN+‖Tφ（X）‖F，（30）can be rewritten asThen，we can obtainAccording to Lemma 1，it can be concluded that the fast terminal sliding manifold s2can converge to the equilibrium point within a finite timet1given by3）Once the sliding surface s2=0 is achieved.the states of system（8）will remain on it and the system has the invariant properties.On the sliding surface s2=0，we can obtainConstructing the following Lyapunov candidateand differentiating V2along（34），we haveThen，we can conclude that the funnel error s2will converge to the equilibrium point.Thus，from（14），the tracking error e will fall into the prescribed boundaries.Remark 2 Since the discontinuous switching functionsgn（·）shown in （22）may result in the chattering phenomenon，the following continuousΔ（s）is employed instead in the simulation section:whereζis a positive constant defining the thickness of the boundary layer. When|s|≥ζ，the proof can be easily accomplished according to the proof of Theorem 1.When|s|＜ζ，following the proof steps in［30］，we can alsoobtainandActually，there exists a small positive constantϵsuch that ϵ≤（|s|+ζ）.With this modified controller，the chattering can be eliminated and the finite-time convergence is guaranteed in the whole tracking process.In this section，the following three other control approaches are presented for the performance comparison with the proposed NTSMFC scheme.1）PID controlwhere kp=20，ki=0.05，and kd=4.2）Neural-network sliding mode control（SMC）［31］where s1=e，b0=6，α=2，k1=10，andµ=0.1.3）Neural-network sliding mode control（NTSMC）［21］where s1=e，α=2，β=0.2，k1=10，p=5，q=7，b0=6 andµ=0.1.For fair comparison，all control parameters are fixed for various reference signals.The initial states of the system are x1（0）=0，x2（0）=0.The NN parameters are K=0.1，a=2，b=10，c=1，d=-10.The parameters of funnel boundary（13）are chosen as δ0=100，δ∞=0.3 and a0=3.And the control law（22），where α=2，β=0.2，k1=10，p=5，q=7，b0=6 and µ=0.1.The system is select as h=0.2x2sinx2and b=6.The saturation bound vmax=1.In the following，three different cases are performed to compare four different controllers.Case 1 Sinusoidal wave.yd=0.5sint is employed as thereference.Simulation has been conducted，and two comparative resultsare shown in Fig.3.The tracking performance and tracking errors are depicted in Fig.3（a）and Fig.3（b），respectively.AsshowninFig.3（a），whentracking the sinusoidal wave，the NTSMFC and the NTSMC have the comparatively lower overshoot，while the PID control scheme has the largest overshoot.From Fig.3（b），we can see that the NTSMFC has the smallest tracking error and fastest convergence speed；NTSMC has the largest overshoot at the beginning，and the PID scheme has the largest steady tracking error.Case 2 Sinusoidal wave with harmonic.The trackingperformanceofthereferencesignal0.5（sint+sin0.5t）is shown in Fig.4.Among the four schemes，the NTSMFC has the smallest overshoot and tracking error with the fastest convergence speed.The SMC and NTSMC have a large overshoot at the beginning，and PID control has largest tracking error when time goes to the infinity.Obviously，NTSMFC has the best performance when tracking the the reference signal 0.5（sint+sin0.5t）.Case 3 Step signal.To further justify the transient performance（e.g.，overshoot），a step signal with amplitude 1 rad is employed.Control parameters are set the same as those given before.As shown in Fig.5，we can see that PID control has comparatively larger overshoot.Besides，the proposed scheme can converge within 1 s，while PID control costs 1.5 s；SMC and NTSMC cost more than 4 s to achieve the same performance.Therefore，we can conclude that the proposed NTSMFC has the best transient performance.In order to show the comparison performance more convincingly，several indices are provided to evaluate the performance of the four controllers. 1），which is the integrated absolute value of the error to measure intermediate tracking result.2）which is the integral of the time multiplied by the absolute value of the error，and used to measure the tracking performance with time behaving as a factor to emphasize errors occurring late.3）which is the integrated square error and used to demonstrate the smoothness of the profile.The simulation results in terms of performance indices are provided by Tables 1-3.From Tables 1-2，we can see that when tracking sinusoidal waves，the proposed NTSMFC scheme has the smallest IAE，ITAE and ISDE，which means it performs best among four controllers.From Table 3，it can be concluded that when tracking the step signal，although PID controller has the smallest ISDE，it has the larger ITAE and IAE than NTSMFC，while SMC and NTSMC have relatively large IAE，ITAE and ISDE. Therefore，all the aforementioned simulation results clearly show that the proposed NTSMFC scheme can achieve the best tracking performance with respect to tracking errors and convergence speed.In this paper，a nonsingular terminal sliding mode funnel control （NTSMFC）scheme is proposed to achieve a prescribed tracking performance for motor servo systems with unknown input saturation.The non-smooth saturationistransformedintoanaffineformbydefiningasmoothnon-affine function and using the mean-value theorem.A new constraint variable is employed and the tracking error will be forced to fall into prescribe boundaries.By using a simple sigmoid neural network to approximate the unknown system nonlinearity，a nonsingular terminal sliding mode funnel control is developed for the prescribed tracking performance of the motor servo system.With the proposed scheme，no prior knowledge is required on the input saturation bound，and the convergence of the position tracking error is guaranteed via the Lyapunov synthesis.Our further work is to apply the proposed scheme to a practical motor servo system.References:［1］LI S H，LIU Z.Adaptive speed control for permanent-magnet synchronous motor system with variations of load inertia［J］.IEEE Transactions on Industrial Electronics，2009，56（8）:3050-3059.［2］MORAWIEC M.The adaptive backstepping control of permanent magnet synchronous motor supplied by current source inverter［J］. IEEE Transactions on Industrial Informatics，2013，9（2）:1047-1055.［3］LIU G，CHEN L，ZHAO W，et al.Internal model control of permanent magnet synchronous motor using support vector machine generalized inverse［J］.IEEE Transactions on Industrial Informatics，2013，9（2）:890-898.［4］TEE K P，REN B B，GE S S.Control of nonlinear systems with time-varying output constraints［J］.Automatica，2011，47（11）:2511 -2516. ［5］NIU B，ZHAO J.Barrier Lyapunov functions for the output trackingcontrol of constrained nonlinear switched systems［J］.Systems& Control Letters，2013，62（10）:963-971.［6］LI Y，LI T，JING X.Indirect adaptive fuzzy control for input and output constrained nonlinear systems using a barrier Lyapunov function ［J］.International Journal of Adaptive Control and Signal Processing，2014，28（2）:184-199.［7］BECHLIOULIS C P，ROVITHAKIS G A.Robust partial-state feedback prescribed performance control of cascade systems with unknown nonlinearities［J］.IEEE Transactions on Automatic Control，2011，56（9）:2224-2230.［8］NA J.Adaptive prescribed performance control of nonlinear systems with unknown dead zone［J］.International Journal of Adaptive Control and Signal Processing，2013，27（5）:426-446.［9］NA J，CHEN Q，REN X M，et al.Adaptive prescribed performance motion control of servo mechanisms with friction compensation［J］. IEEE Transactions on Industrial Electronics，2014，61（1）:486-494.［10］ILCHMANA，SCHUSTERH.Trackingcontrolwithprescribedtransient behavior degree［J］.Systems&Control Letters，2006，55（5）: 396-406. ［11］ILCHMAN A，RYAN E P，TRENN S.PI-funnel control for two mass systems［J］.IEEE Transactions on Affective Computing，2009，54（4）: 918-923.［12］HACKL C M，ENDISCH C，SCHRODER D.Contribution to nonidentifier based adaptive control in mechatronics［J］.Robotics and Autonomous Systems，2009，57（10）:996-1005.［13］HACKL C M.High-gain position control［J］.International Journal of Control，2011，84（10）:1695-1716.［14］HAN S I，LEE J M.Recurrent fuzzy neural network backstepping control for the prescribed output tracking performance of nonlinear dynamic systems［J］.ISA transactions，2014，53（1）:33-43.［15］HAN S I，LEE J M.Fuzzy echo state neural networks and funnel dynamic surface control for prescribed performance of a nonlinear dynamic system［J］.IEEE Transactions on Industrial Electronics，2014，61（2）:1099-1112.［16］IMURA J，SUGIE T，YOSHIKAWA T.Adaptive robust control of robot manipulators-Theory and experiment［J］.IEEE Transactions on Robotics and Automation，1994，10（5）:705-710.［17］XU L，YAO B.Adaptive robust precision motion control of linear motors with negligible electrical dynamics:theory and experiments ［J］.IEEE Transactions on Mechatronics，2001，6（4）:444-452.［18］MAN Z H，YU X H.Adaptive terminal sliding mode tracking control for rigid robotic manipulators with uncertain dynamics［J］.International Journal of Mechanical Systems，Machine Elements，and Manufacturing，1997，40（3）:493-502.［19］FENG Y，YU X H，MAN Z H.Non-singular terminal slidng mode control of rigid manipulators［J］.Automatica，2002，38（12）:2159-2167. ［20］YU S，YU X H，SHIRINZADEHC B.Continuous finite-time control for robotic manipulators with terminal sliding mode［J］.Automatica，2005，41（11）:1957-1964.［21］CHEN S Y，LIN F J.Robust nonsingular terminal sliding-mode control for nonlinear magnetic bearing system［J］.IEEE Transactions on Control Systems Technology，2011，19（3）:636-643.［22］PEREZ-ARANCIBIA N O，TSAO T C，GIBSON J S.Saturationinduced instability and its avoidance in adaptive control of hard disk drives［J］.IEEE Transactions on Control Systems Technology，2010，18（2）:368-382.［23］GAOW Z，SELMIC R R.Neural networkcontrol of a class of nonlinear systems with actuator saturation［J］.IEEE Transactions on Neural Networks，2006，17（1）:147-156.［24］HU Q L，MA G F，XIE L H.Robust and adaptive variable structure output feedback control of uncertain systems with input nonlinearity ［J］.Automatica，2008，44（4）:552-559.［25］CHEN M，GE S S，HOW B.Robust adaptive neural network control for a class of uncertain MIMO nonlinear systems with input nonlinearities ［J］.IEEE Transactions on Neural Networks，2010，21（5）:796 -812. ［26］CHEN M，GE S S，REN B B.Adaptive tracking control of uncertain MIMO nonlinear systems with input constraints［J］.Automatica 2011，47（3）:452-455.［27］ZHANG X，WANG M，ZHAO J.Stability analysis and antiwindup design of uncertain discrete-time switched linear systems subject to actuator saturation［J］.Journal of Control Theory and Applications，2012，10（3）:325-331.［28］WEN C Y，ZHOU J，LIU Z T，et al.Robust adaptive control ofuncertain nonlinear systems in the presence of input saturation and external disturbance［J］.IEEE Transactions on Automatic Control，2011，56（7）:1672-1678.［29］WANG H，CHEN B，LIU X，et al.Adaptive neural tracking control for stochastic nonlinear strict-feedback systems with unknown input saturation［J］.Information Sciences，2014，269（6）:300-315.［30］LIU H T，ZHANG T.Neural network-based robust finite-time control for robotic manipulators considering actuator dynamics［J］.Robotics and Computer-Integrated Manufacturing，2013，29（2）:301-308.［31］CHEN Q，NAN Y R，JIN Y.Neural sliding mode control for turntable servo system with unknown deadzone［C］//Proceedings of the 32nd Chinese Control Conference.Xi’an，China，2013.陈强（1984-），男，讲师，目前研究方向为交流伺服电机控制、非线性摩擦和死区补偿、自适应神经网络控制等，E-mail:****************.cn；汤筱晴（1993-），女，目前研究方向为滑模自适应控制，E-mail:**********************.。

C++常见的编译错误中英对应翻译对于刚学编程，刚接触C++的新手来说，编译运行报错是最头疼的一件事，爆出一堆英文，英语差一点的又不知道什么意思，所以也不知道如何去改，在此，我给大家传一份常见错误中英文对照表及简单解释，希望可以帮到大家：fatal error C1003: error count exceeds number; stopping compilation中文对照：（编译错误）错误太多，停止编译分析：修改之前的错误，再次编译fatal error C1004: unexpected end of file found中文对照：（编译错误）文件未结束分析：一个函数或者一个结构定义缺少“}”、或者在一个函数调用或表达式中括号没有配对出现、或者注释符“/*…*/”不完整等fatal error C1083: Cannot open include file: 'xxx': No such file or directory中文对照：（编译错误）无法打开头文件xxx：没有这个文件或路径分析：头文件不存在、或者头文件拼写错误、或者文件为只读fatal error C1903: unable to recover from previous error(s); stopping compilation中文对照：（编译错误）无法从之前的错误中恢复，停止编译分析：引起错误的原因很多，建议先修改之前的错误error C2001: newline in constant中文对照：（编译错误）常量中创建新行分析：字符串常量多行书写error C2006: #include expected a filename, found 'identifier'中文对照：（编译错误）#include命令中需要文件名分析：一般是头文件未用一对双引号或尖括号括起来，例如“#include stdio.h”error C2007: #define syntax中文对照：（编译错误）#define语法错误分析：例如“#define”后缺少宏名，例如“#define”error C2008: 'xxx' : unexpected in macro definition中文对照：（编译错误）宏定义时出现了意外的xxx分析：宏定义时宏名与替换串之间应有空格，例如“#define TRUE"1"”error C2009: reuse of macro formal 'identifier'中文对照：（编译错误）带参宏的形式参数重复使用分析：宏定义如有参数不能重名，例如“#define s(a,a) (a*a)”中参数a重复error C2010: 'character' : unexpected in macro formal parameter list中文对照：（编译错误）带参宏的形式参数表中出现未知字符分析：例如“#define s(r|) r*r”中参数多了一个字符‘|’error C2014: preprocessor command must start as first nonwhite space中文对照：（编译错误）预处理命令前面只允许空格分析：每一条预处理命令都应独占一行，不应出现其他非空格字符error C2015: too many characters in constant中文对照：（编译错误）常量中包含多个字符分析：字符型常量的单引号中只能有一个字符，或是以“\”开始的一个转义字符，例如“char error = 'error';”error C2017: illegal escape sequence中文对照：（编译错误）转义字符非法分析：一般是转义字符位于' ' 或" " 之外，例如“char error = ' '\n;”error C2018: unknown character '0xhh'中文对照：（编译错误）未知的字符0xhh分析：一般是输入了中文标点符号，例如“char error = 'E'；”中“；”为中文标点符号error C2019: expected preprocessor directive, found 'character'中文对照：（编译错误）期待预处理命令，但有无效字符分析：一般是预处理命令的#号后误输入其他无效字符，例如“#!define TRUE 1”error C2021: expected exponent value, not 'character'中文对照：（编译错误）期待指数值，不能是字符分析：一般是浮点数的指数表示形式有误，例如123.456Eerror C2039: 'identifier1' : is not a member of 'identifier2'中文对照：（编译错误）标识符1不是标识符2的成员分析：程序错误地调用或引用结构体、共用体、类的成员error C2041: illegal digit 'x' for base 'n'中文对照：（编译错误）对于n进制来说数字x非法分析：一般是八进制或十六进制数表示错误，例如“int i = 081;”语句中数字‘8’不是八进制的基数error C2048: more than one default中文对照：（编译错误）default语句多于一个分析：switch语句中只能有一个default，删去多余的defaulterror C2050: switch expression not integral中文对照：（编译错误）switch表达式不是整型的分析：switch表达式必须是整型（或字符型），例如“switch ("a")”中表达式为字符串，这是非法的error C2051: case expression not constant中文对照：（编译错误）case表达式不是常量分析：case表达式应为常量表达式，例如“case "a"”中“"a"”为字符串，这是非法的error C2052: 'type' : illegal type for case expression中文对照：（编译错误）case表达式类型非法分析：case表达式必须是一个整型常量（包括字符型）error C2057: expected constant expression中文对照：（编译错误）期待常量表达式分析：一般是定义数组时数组长度为变量，例如“int n=10; int a[n];”中n为变量，这是非法的error C2058: constant expression is not integral中文对照：（编译错误）常量表达式不是整数分析：一般是定义数组时数组长度不是整型常量error C2059: syntax error : 'xxx'中文对照：（编译错误）‘xxx’语法错误分析：引起错误的原因很多，可能多加或少加了符号xxxerror C2064: term does not evaluate to a function中文对照：（编译错误）无法识别函数语言分析：1、函数参数有误，表达式可能不正确，例如“sqrt(s(s-a)(s-b)(s-c));”中表达式不正确2、变量与函数重名或该标识符不是函数，例如“int i,j; j=i();”中i不是函数error C2065: 'xxx' : undeclared identifier中文对照：（编译错误）未定义的标识符xxx分析：1、如果xxx为cout、cin、scanf、printf、sqrt等，则程序中包含头文件有误2、未定义变量、数组、函数原型等，注意拼写错误或区分大小写。

C语言常见错误提示信息的英汉对照常见错误提示信息的英汉对照Ambiguous operators need parentheses : 不明确的运算需要用括号括起Ambiguous symbol ’xxx’ : 不明确的符号Argument list syntax error : 参数表语法错误Array bounds missing : 丢失数组界限符Array size toolarge : 数组尺寸太大Bad character in paramenters :参数中有不适当的字符Bad file name format in include directive :包含命令中文件名格式不正确Bad ifdef directive synatax :编译预处理ifdef有语法错Bad undef directive syntax :编译预处理undef有语法错Bit field too large :位字段太长Call of non-function :调用未定义的函数Call to function with no prototype :调用函数时没有函数的说明Cannot modify a const object :不允许修改常量对象Case outside of switch: 漏掉了case 语句Case syntax error :Case 语法错误Code has no effect 代码不可述不可能执行到Compound statement missing{ 分程序漏掉"{"Conflicting type modifiers 不明确的类型说明符Constant expression required 要求常量表达式Constant out of range in comparison 在比较中常量超出范围Conversion may lose significant digits 转换时会丢失意义的数字Conversion of near pointer not allowed 不允许转换近指针Could not find file ’xxx’ 找不到XXX文件Declaration missing ; 说明缺少"；"Declaration syntax error 说明中出现语法错误Default outside of switch Default 出现在switch语句之外Define directive needs an identifier 定义编译预处理需要标识符Division by zero 用零作除数Do statement must have while Do-while语句中缺少while部分Enum syntax error 枚举类型语法错误Enumeration constant syntax error 枚举常数语法错误Error directive :xxx 错误的编译预处理命令Error writing output file 写输出文件错误Expression syntax error 表达式语法错误Extra parameter in call 调用时出现多余错误File name too long 文件名太长Function call missing ) 函数调用缺少右括号Fuction definition out of place 函数定义位置错误Fuction should return a value 函数必需返回一个值Goto statement missing label Goto语句没有标号Hexadecimal or octal constant too large 16进制或8进制常数太大Illegal character ’x’ 非法字符xIllegal initialization 非法的初始化Illegal octal digit 非法的8进制数字Illegal pointer subtraction 非法的指针相减Illegal structure operation 非法的结构体操作Illegal use of floating point 非法的浮点运算Illegal use of pointer 指针使用非法Improper use of a typedefsymbol 类型定义符号使用不恰当In-line assembly not allowed 不允许使用行间汇编Incompatible storage class 存储类别不相容Incompatible type conversion 不相容的类型转换Incorrect number format 错误的数据格式Incorrect use of default Default使用不当Invalid indirection 无效的间接运算Invalid pointer addition 指针相加无效Irreducible expression tree 无法执行的表达式运算Lvalue required 需要逻辑值0或非0值Macro argument syntax error 宏参数语法错误Macro expansion too long 宏的扩展以后太长Mismatched number of parameters in definition 定义中参数个数不匹配Misplaced break 此处不应出现break语句Misplaced continue 此处不应出现continue语句Misplaced decimal point 此处不应出现小数点Misplaced elif directive 不应编译预处理elif Misplaced else 此处不应出现elseMisplaced else directive 此处不应出现编译预处理else Misplaced endif directive 此处不应出现编译预处理endif Must be addressable 必须是可以编址的Must take address of memory location 必须存储定位的地址No declaration for function ’xxx’ 没有函数xxx的说明No stack 缺少堆栈No type information 没有类型信息Non-portable pointer assignment 不可移动的指针（地址常数）赋值Non-portable pointer comparison 不可移动的指针（地址常数）比较Non-portable pointer conversion 不可移动的指针（地址常数）转换Not a valid expression format type 不合法的表达式格式Not an allowed type 不允许使用的类型Numeric constant too large 数值常太大Out of memory 内存不够用Parameter ’xxx’ is never used 能数xxx没有用到Pointer required on left side of -> 符号->的左边必须是指针Possible use of ’xxx’ before definition 在定义之前就使用了xxx（警告）Possibly incorrect assignment 赋值可能不正确Redeclaration of ’xxx’ 重复定义了xxx Redefinition of ’xxx’ is not identical x xx的两次定义不一致Register allocation failure 寄存器定址失败Repeat count needs an lvalue 重复计数需要逻辑值Size of structure or array not known 结构体或数给大小不确定Statement missing ; 语句后缺少"；"Structure or union syntax error 结构体或联合体语法错误Structure size too large 结构体尺寸太大Sub scripting missing ] 下标缺少右方括号Superfluous & with function or array 函数或数组中有多余的"&"Suspicious pointer conversion 可疑的指针转换Symbol limit exceeded 符号超限Too few parameters in call 函数调用时的实参少于函数的参数Too many default cases Default太多(switch语句中一个)Too many error or warning messages 错误或警告信息太多Too many type in declaration 说明中类型太多Too much auto memory in function 函数用到的局部存储太多Too much global data defined in file 文件中全局数据太多Two consecutive dots 两个连续的句点Type mismatch in parameter xxx 参数xxx类型不匹配Type mismatch in redeclaration of ’xxx’ xxx重定义的类型不匹配Unable to create output file ’xxx’ 无法建立输出文件xxx Unable to open include file ’xxx’ 无法打开被包含的文件xxx Unable to open input file ’xxx’ 无法打开输入文件xxx Undefined label ’xxx’ 没有定义的标号xxx Undefined structure ’xxx’ 没有定义的结构xxx Undefined symbol ’xxx’ 没有定义的符号xxx Unexpected end of file in comment started on line xxx 从xxx行开始的注解尚未结束文件不能结束Unexpected end of file in conditional started on line xxx 从xxx 开始的条件语句尚未结束文件不能结束Unknown assemble instruction 未知的汇编结构Unknown option 未知的操作Unknown preprocessor directive: ’xxx’ 不认识的预处理命令xxx Unreachable code 无路可达的代码Unterminated string or character constant 字符串缺少引号User break 用户强行中断了程序Void functions may not return a value Void类型的函数不应有返回值Wrong number of arguments ：调用函数的参数数目错‘xxx’ not an argument :xxx不是参数‘xxx’ not part o f struc ture xxx不是结构体的一部分xxx statement missing ( xxx语句缺少左括号xxx statement missing ) xxx语句缺少右括号xxx statement missing ; xxx缺少分号xxx’ declared but never used 说明了xxx但没有使用xxx’ is assigned a value which is never used 给xxx赋了值但未用过。

C++常见的编译错‎误中英对应翻‎译对于刚学编程‎，刚接触C++的新手来说，编译运行报错‎是最头疼的一‎件事，爆出一堆英文‎，英语差一点的‎又不知道什么‎意思，所以也不知道‎如何去改，在此，我给大家传一‎份常见错误中‎英文对照表及‎简单解释，希望可以帮到‎大家：fatal error C1003: error count exceed‎s number‎; stoppi‎n g compil‎a tion中文对照：（编译错误）错误太多，停止编译分析：修改之前的错‎误，再次编译fatal error C1004: unexpe‎c ted end of file found中文对照：（编译错误）文件未结束分析：一个函数或者‎一个结构定义‎缺少“}”、或者在一个函‎数调用或表达‎式中括号没有‎配对出现、或者注释符“/*…*/”不完整等fatal error C1083: Cannot‎open includ‎e file: 'xxx': No such file or direct‎o ry中文对照：（编译错误）无法打开头文‎件x xx：没有这个文件‎或路径分析：头文件不存在‎、或者头文件拼‎写错误、或者文件为只‎读fatal error C1903: unable‎to recove‎r from previo‎u s error(s); stoppi‎n g compil‎a tion中文对照：（编译错误）无法从之前的‎错误中恢复，停止编译分析：引起错误的原‎因很多，建议先修改之‎前的错误error C2001: newlin‎e in consta‎n t中文对照：（编译错误）常量中创建新‎行分析：字符串常量多‎行书写error C2006: #includ‎e expect‎e d a filena‎m e, found 'identi‎f ier'中文对照：（编译错误）#includ‎e命令中需要‎文件名分析：一般是头文件‎未用一对双引‎号或尖括号括‎起来，例如“#includ‎e stdio.h”error C2007: #define‎syntax‎中文对照：（编译错误）#define‎语法错误分析：例如“#define‎”后缺少宏名，例如“#define‎”error C2008: 'xxx' : unexpe‎c ted in macro defini‎t ion中文对照：（编译错误）宏定义时出现‎了意外的xx‎x分析：宏定义时宏名‎与替换串之间‎应有空格，例如“#define‎TRUE"1"”error C2009: reuse of macro formal‎'identi‎f ier'中文对照：（编译错误）带参宏的形式‎参数重复使用‎分析：宏定义如有参‎数不能重名，例如“#define‎s(a,a) (a*a)”中参数a重复‎error C2010: 'charac‎t er' : unexpe‎c ted in macro formal‎parame‎t er list中文对照：（编译错误）带参宏的形式‎参数表中出现‎未知字符分析：例如“#define‎s(r|) r*r”中参数多了一‎个字符‘|’error C2014: prepro‎c essor‎comman‎d must start as first nonwhi‎t e space中文对照：（编译错误）预处理命令前‎面只允许空格‎分析：每一条预处理‎命令都应独占‎一行，不应出现其他‎非空格字符error C2015: too many charac‎t ers in consta‎n t中文对照：（编译错误）常量中包含多‎个字符分析：字符型常量的‎单引号中只能‎有一个字符，或是以“\”开始的一个转‎义字符，例如“char error = 'error';”error C2017: illega‎l escape‎sequen‎c e中文对照：（编译错误）转义字符非法‎分析：一般是转义字‎符位于' ' 或" " 之外，例如“char error = ' '\n;”error C2018: unknow‎n charac‎t er '0xhh'中文对照：（编译错误）未知的字符0‎x hh分析：一般是输入了‎中文标点符号‎，例如“char error = 'E'；”中“；”为中文标点符‎号error C2019: expect‎e d prepro‎c essor‎direct‎i ve, found 'charac‎t er'中文对照：（编译错误）期待预处理命‎令，但有无效字符‎分析：一般是预处理‎命令的#号后误输入其‎他无效字符，例如“#!define‎TRUE 1”error C2021: expect‎e d expone‎n t value, not 'charac‎t er'中文对照：（编译错误）期待指数值，不能是字符分析：一般是浮点数‎的指数表示形‎式有误，例如123.456Eerror C2039: 'identi‎f ier1' : is not a member‎of 'identi‎f ier2'中文对照：（编译错误）标识符1不是‎标识符2的成‎员分析：程序错误地调‎用或引用结构‎体、共用体、类的成员error C2041: illega‎l digit 'x' for base 'n'中文对照：（编译错误）对于n进制来‎说数字x非法‎分析：一般是八进制‎或十六进制数‎表示错误，例如“int i = 081;”语句中数字‘8’不是八进制的‎基数error C2048: more than one defaul‎t中文对照：（编译错误）defaul‎t语句多于一‎个分析：switch‎语句中只能有‎一个defa‎u l t，删去多余的d‎e fault‎error C2050: switch‎expres‎s ion not integr‎a l中文对照：（编译错误）switch‎表达式不是整‎型的分析：switch‎表达式必须是‎整型（或字符型），例如“switch‎("a")”中表达式为字‎符串，这是非法的error C2051: case expres‎s ion not consta‎n t中文对照：（编译错误）case表达‎式不是常量分析：case表达‎式应为常量表‎达式，例如“case "a"”中“"a"”为字符串，这是非法的error C2052: 'type' : illega‎l type for case expres‎s ion中文对照：（编译错误）case表达‎式类型非法分析：case表达‎式必须是一个‎整型常量（包括字符型）error C2057: expect‎e d consta‎n t expres‎s ion中文对照：（编译错误）期待常量表达‎式分析：一般是定义数‎组时数组长度‎为变量，例如“int n=10; int a[n];”中n为变量，这是非法的error C2058: consta‎n t expres‎s ion is not integr‎a l中文对照：（编译错误）常量表达式不‎是整数分析：一般是定义数‎组时数组长度‎不是整型常量‎error C2059: syntax‎error : 'xxx'中文对照：（编译错误）‘xxx’语法错误分析：引起错误的原‎因很多，可能多加或少‎加了符号xx‎xerror C2064: term does not evalua‎t e to a functi‎o n中文对照：（编译错误）无法识别函数‎语言分析：1、函数参数有误‎，表达式可能不‎正确，例如“sqrt(s(s-a)(s-b)(s-c));”中表达式不正‎确2、变量与函数重‎名或该标识符‎不是函数，例如“int i,j; j=i();”中i不是函数‎error C2065: 'xxx' : undecl‎a red identi‎f ier中文对照：（编译错误）未定义的标识‎符x xx分析：1、如果xxx为‎c o ut、cin、scanf、printf‎、sqrt等，则程序中包含‎头文件有误2、未定义变量、数组、函数原型等，注意拼写错误‎或区分大小写‎。

Remote Class is UncategorizedIntroductionIn the era of digitalization, remote learning has become increasingly popular. With the advancements in technology and the internet, students can now attend classes from anywhere in the world. This new form of education is commonly known as a remote class. However, despite its widespread use, the classification of remote classes remains uncategorized. In this article, we will explore what a remote class is, its benefits and challenges, and discuss possible ways to categorizethis form of education.What is a Remote Class?A remote class refers to an educational setting where students and teachers are physically separated but connected through technology. Instead of attending traditional face-to-face classes in a physical classroom, students participate in virtual classrooms using various online platforms such as video conferencing tools or learning management systems.Remote classes offer flexibility for both students and teachers. They allow individuals to access education from any location with an internet connection. This form of learning has gained significant popularity due to its convenience and potential cost savings.Benefits of Remote Classes1. FlexibilityOne of the major advantages of remote classes is flexibility. Students can attend lectures at their own pace and choose their preferred study environment. They have the freedom to schedule their learning around other commitments such as work or personal responsibilities.2. Accessible EducationRemote classes have made education more accessible to people who may face geographical barriers or physical disabilities. Students living in rural areas or areas with limited educational resources can now access quality education without having to relocate.3. Global Learning OpportunitiesRemote classes provide opportunities for global collaboration andcultural exchange among students from different parts of the world. Students can interact with peers from diverse backgrounds, enhancingtheir understanding of different cultures and perspectives.4. Enhanced Digital SkillsParticipating in remote classes requires students to develop digital literacy skills and adaptability to online platforms. These skills are vital in today’s technology-driven world and can benefit students in their future careers.Challenges of Remote ClassesWhile remote classes offer numerous benefits, they also present certain challenges that need to be addressed.1. Lack of Face-to-Face InteractionOne of the main challenges of remote classes is the absence of face-to-face interaction. Traditional classrooms provide opportunities for immediate feedback, non-verbal communication, and social interactions.In remote classes, students may miss out on these aspects, impactingtheir overall learning experience.2. Technological IssuesReliable internet access and technical difficulties can hinder the smooth functioning of remote classes. Students and teachers may face connectivity issues, audio/video problems, or compatibility issues with online platforms. These technical challenges can disrupt the learning process and create frustration for both parties involved.3. Self-Motivation and Time ManagementRemote classes require self-discipline and strong time management skills. Without a physical classroom environment and direct supervision,students must take responsibility for their own learning progress. Some students may find it challenging to stay motivated and keep up with coursework without regular face-to-face interactions.4. Educational EquityRemote classes may exacerbate existing educational inequalities. Not all students have equal access to reliable internet connections or suitable devices for online learning. This disparity can widen the educational gap between privileged and disadvantaged students if not addressed properly.Categorizing Remote ClassesTo categorize remote classes effectively, several factors need to be considered:1.Synchronous vs Asynchronous: Remote classes can be categorizedbased on whether they are delivered in real-time (synchronous) or pre-recorded (asynchronous). Synchronous classes allow immediateinteraction between teachers and students, while asynchronousclasses provide flexibility in terms of when learners access thecontent.2.Subject-based: Remote classes can be categorized based on subjectareas such as mathematics, science, humanities, or language arts.This categorization can help students find classes that align with their interests and academic goals.3.Level of Education: Remote classes can be categorized based onthe level of education, such as primary, secondary, or highereducation. This categorization ensures that appropriate contentand teaching methods are used for different age groups.4.Platform-based: Remote classes can be categorized based on theonline platforms used for delivery, such as video conferencingtools, learning management systems, or specialized educationalplatforms. This categorization helps students and teachersidentify the most suitable technology for their needs.5.Geographical Scope: Remote classes can also be categorized basedon their geographical scope, such as international remote classes or region-specific remote classes. This categorization enablesstudents to explore global learning opportunities or focus onspecific local contexts.By considering these factors, remote classes can be effectively categorized to facilitate easier access and navigation for students and teachers alike.ConclusionRemote classes have revolutionized the way education is delivered and accessed worldwide. Despite being widely adopted, they remain uncategorized in terms of classification. Understanding the benefits and challenges of remote classes is crucial for both educators and learners to make the most out of this form of education. By categorizing remote classes based on factors such as synchronous/asynchronous delivery, subject areas, level of education, platform usage, and geographical scope, we can enhance the overall learning experience and ensure equitable access to quality education for all.。

出《----》入，上《----》下disgorge ingestexcrete ingestinsert removeradiate absorbemit absorbaerate remove air from disinter buryascend go downdoff donabdicate assume花草，气候，色彩等inclement balmynoisome attractively fragrant verdant sereburgeon withersubsidevariegation uniform coloration pied solid-colored flamboyant subduedrefulgent lackluster lackluster radiantflourish lack of embellishment战争，政权bellicose pacifictruce resumed fightingvictor loserdebacle complete success disarm put on guard incursion retreatcapitulation resistanceminatory unthreatening vulnerable safeprecarious safehaven dangerous place mogul nonentity hegemony lack of authority peremptory open to challenge有限《----》无限，多《----》少infinity bounded spacequota unlimited number pandemic limitedslew limited quantity vacuity plenitudeenrich depletesurfeit famishstarvesurcharge discountrarefy make more dense frequency raritypurlieu infrequently visited place走，看，找meander move purposivelyloll move vigorously gambol plodflit plodlumber glidedispatch leisurelinessplumb examine superficially scrutinize gloss overscrutiny casual glanceeschew seekshun seek activelyorient confuse夸张《----》低估，炫耀《----》恭谦exaggerate minimizeminimize overestimate hyperbole understatement grandiloquent secretivehubris humilityblatant unobtrusive ostentation austeritystaid jaunty减轻《-----》加重，抚慰《-----》激怒assuage intensifyharrow assuagemitigate exacerbate alleviate exacerbate aggravate alleviate ameliorate aggregate extenuating aggravating console aggravate grief palliate increase the intensity pique mollifymollify irerousepropitiate arouse hostility rankle pacify增减，扩缩，强弱balloon decrease slowly dwindle increase proliferate dwindledistension compression constrict dilatedilate narrow commodious crampedabate augmentflag waxdamped amplifiedmute amplifyfirm muteaggrandize relegateenervate strengthen attenuate strengthensubvert reinforce undermine undergird undermine reinforce纯净《-----》污染，挥霍《----》吝啬sterilize contaminatepristine contaminate maculated unspottedvenal incorruptible prodigality penuryfrugalityprofuse scant松弛《-----》崩紧，束缚《----》释放slack tauttaut loose or unfirmconstrain releasefetter liberateenfranchise enfetter高低，胖瘦，形变nadir topmost pointzenith nadirfringe centeremaciate fattensquat tall and thin metamorphosis continuation without change elasticity lack of resilience平滑《-----》粗糙，笔直《----》弯斜crass refinedcorrugated smoothspiny smoothlimp smoothviscid slicktortuous straightforwardsinuous directplumb horizontallist be upright模糊神秘《----》清楚公开indeterminate definitevague well definedlucid vaguemurkyenigmatic free of ambiguitycryptic self-explanatory hermetic easily comprehended occult readily fathomablebarecovert openrecondite widely understood esoteric generally known allude mention explicitly intimate communicate directly promulgate keep secretevince conceal dissembling candidstipulation requirementsubtle obvious profundity superficialitypith superficial element dominant recessive顺从温和《----》固执暴躁complaisance churlishness obdurate complaisant tractable headstrong obstinate tractable obstinacy tractability tractability incorrigibility inveterate casual recalcitrant amendablesubmissive alacrity recalcitrance conform not hew to plasticity rigidityasperity mildnessmildness of temper truculent gentle curmudgeon agreeable person affable irascibleferal cultivated instinct learned response正直《----》卑鄙，诚实《-----》狡诈turpitude saintly behaviorprobityprobity unscrupulousness sublime basesplendor squalor ingenuous cunningartlessness cunningguilemanipulative guilelessdisingenuousness guilelessnesschicanery honest dealingaboveboard actionprevarication veracityquack honest practitionerinveigle open seek to persuadeperfidy loyaltytreacherousness faithfulnessdefault fulfill an obligation批评Fulminate, denounce, condemn, reprehend,Rail, inveigh, censure, upbraid, chastise,Chide, belabor, lambaste, vituperate, castigate,Reprimand, berate, reprove, rebuke, revile, excoriate,Reproach, opprobrium, impugn, flay, pan, stricture赞扬Commend, extol, exalt, acclaim, laud, eulogize, accolade, Applaud, glorify, rave, tribute, plaudits, approbation, orchid, encomium赞美诗Panegyric, eulogy, hymn, paean, carol, psalm刚开始的，入门状态Inchoate, nascent, incipient, rudimentary, embryonicFlippant-----------earnestNexus disconnected componentsLevy rescindEffrontery decorumLimpid turbidRefute proveFatuousness sensiblenessTimorous intrepid尊敬《-》嘲笑，严肃《-》轻率Veneration derision Revere profaneDeference contempt Opprobrium reputeEstimable infamousDeride show respect for Pillory exaltBadinage serious conversation Levity seriousnessGravityBlithe graveFlippant earnest支持《-》削弱，同意《-》拒绝Abrogate upholdSap bolsterBolster decrease support of Undermine undergirdDisaffect win overEndorse oppose publicly Inconsonant in agreement Gainsay concurConcur dissentBrook refuse to tolerate Stomach refuse to tolerate Apprise withhold information证实确信《-》反驳怀疑Rebuff welcomeDispute acceptControvert substantiate Substantiation disproof Unsubstantiated verifiedBelie averAver denyControvert Corroboration lessening of certainty Postulate deny as false Recant affirmClinch make more doubtful Supposition certainty Unpredictable dependableSkepticism conviction Exculpate indictAttribute guilt Exonerate inculpate Innocence guilt真《-》伪Apocryphal authenticated Apocrypha canonCanonical heterodox Dogma heresy Authentic bogusPerjury truthful deposition Prejudiced disinterested tendentious unbiased axiomatic controversial adulteration purification disabuse lead into error inerrancy fallibility fallacious validfallacy valid reasoningvalid argument specious validveritable specious precarious firmly grounded gratuitous warranted阻碍制止《-》促进许可Proscribe sanctionPermit Barricade permit passage Impede assist Stonewall cooperate fully Facilitate thwartHamper Obstructionist one who facilitate Stymie promote Accelerate retardForestall precipitateAbetFrustrate abetFoment inhibitCatalyze inhibitPrompt checkArrest vitalizeAcquiesce resistBoycott patronizeLag forge ahead聚合《-》分散Aggregate disperseIsolated unitsGroup isolateAmalgamate isolateSeparateCompound separateMeldConcatenateCoalesce desegregateCoalesced broke apartSummon dismissFocus disperseDiffuseDeploy concentrate Disseminate garnerCollect scatterSunder linkSuture incisionNexus disconnected components Discrete continuousAffiliation dissociationDisagreementDiverge come together Divergence unificationPartition unifyFactious cooperativeSynergic antagonisticAlly adversary Interlocking independent Autonomy dependenceAlienate reunite Estrangement rapprochementReconciliationRift reconciliation Ensemble soloDisparate homogeneousFastidious indiscriminate完全彻底《-》部分Exhaustive incompletePartialUtter partialIntegrity incompletenessSegment make whole相关性，重要性，合适性Relevant immaterialExtraneous relevantPertain be relevantGermane inappropriateOpportune inconvenientHarmony discordJibe conflictSubstantive trivialExactitude imprecision精神《-》物质Corporeal immaterialIntangibleSpiritual corporealPalpability intangibilitySentient unconscious有关“说话”（简洁-冗长，直接-间接，详细-含糊）Elaborate simplifyProlixity succinctnessExtreme brevityLaconic verboseGarrulousNeologism archaismWell-established expressions Loquacious taciturnWaffle speak unequivocallyMutter speak distinctlyMellifluous cacophonousFluent haltingGlib laboredCircuity straightforwardness ConvolutedTirade dispassionate speech Platitude original observation新生《-》成型Nascent matureFully established Inchoate fully realizedCompletely formed Incipient fully blownVestigial fully developed宁静《-》喧闹Din hushSilenceBoisterous quietQuiescence actionRestless activityLull increased activity Tranquility pandemonium Turbulence tranquilityFracas peaceful situation干燥《-》湿润清澈《-》浑浊Desiccate drenchAdd water toHydrateDehydrate saturate with water Anhydrate wetLimpid turbidSpate trickling flow激烈《-》克制，刺激《-》镇静，敏感《-》免疫Fervid restrainedLibertine asceticMartinet indulgent individual Teetotalism intemperanceEquable intemperance Equanimity excitabilityEvoke fail to elicitDismay heartenGoad lullSoporific stimulantIncentive deterrentBalm irritantAnalgesia sensitivity to pain Pungency blandnessPiquancy blandnessImmunity susceptibilityLiability immunityImmune having no resistance to septic free of infection激动《-》厌倦，高兴《-》忧郁Ennui excitementExuberanceLassitude a feeling of vigor Emaciation invigorationSupine vigilantTorpor extreme excitability Morose lightheartedCheerful Lugubriousness cheerfulnessGrouse rejoiceAlacrity hesitance and reluctance热情《-》冷淡Ebullience impassivenessImpassive overwrought Preoccupation unconcernCompassion indifferenceClemency ruthlessnessAvid indifferentEpicure a person indifferent to food喜欢《-》厌恶Antipathy benevolenceSettled fondnessOdium infatuation Obsession perfunctory interest Penchant dislikeDisposed disinclined Cosseted unspoiled聪明灵巧《-》愚蠢笨拙Fatu ousness sensibleness Virtuosity mediocrity Discernment lack of insight Ingenuity lack of inventiveness Fatuity sagacityFinesse heavy handinessIneptitude Fumble handle adroitly Deft awkward稳定不变《-》摇摆易变，静《-》动Capricious steadfastResolute Versatile unchangeable Labile stableMercurial constant Stability inconstancyRoil settleEnsconce displaceUnsettle Vacillation motionless balance Vacillate resolve firmly Oscillate remain steady Stagnant flowing Peripatetic stationary谨慎认真《-》疏忽仓促Negligence careSedulous careless Inadvertence careful attention Derelict extremely careful Inadvertent intentional Cautious rash Punctilious slipshodCursory painstakingThorough impetuous Deliberate勇敢《-》胆小，坚强《-》无力Intrepid apprehensive Timorous intrepidScrappy timorous Audacious timidCraven valorousDiffident boldCower brazenly confront Bristle cower Redoubtable not formidableUnimpressiveDaunt make resolute Persevere give up Persistence inconstancy Volition inability to choose Clout impuissance Puissance powerlessness福益《-》祸害Hapless fortuneBane blessingBoon misfortuneFluke expected occurrence Insalubrity healthifulness Salutary unhealthyBaleful beneficent繁殖《-》灭绝Derivative seminal Propagate fail to multiply Propagation extirpationExtant extinct时间的长短性，同时性，连续性Evanescent lastingPerpetualPermanentEphemeral enduringSynchronous noncontemporaneousOccurring at different times Abeyance continuanceMeteoric gradual开头《-》结尾Prologue epilogueCoda preludeBegin concludeCessation commencement平凡《-》陈腐，新《-》旧Hackneyed originalTrite originalBanal arrestingRenovate cause to decay Dilapidated restoredDecrepi t sturdy。

;'not allowed before'ELSE'ElSE前不允许有“;”''clause not allowed in OLE automation section在OLE自动区段不允许“”子句''is not a type identifier不是类型标识符''not previously declared as a PROPERTY前面没有说明PROPERTY'GOTO'leads into or out of TRY statement GOTO进入或超出TRY语句的范围clause expected,but found要求子句,但出现16-Bit fixup encountered in object file''在对象文件遇到16位修复486/487instructions not enabled不能用486/487指令Abstract methods must be virtual or dynamic抽象方法必须为虚拟的或动态的Array type required需要数组类型Assignment to FOR-Loop variable''给FOR循环变量赋值Bad argument type in variable type array constructor在变量类型数组结构中不正确的参数类型Bad file format''错误的文件格式Bad file format:错误的文件格式Bad global symbol definition:''in object file''对象文件''中错误的全局符号定义''Bad unit format:错误的单元格式BREAK or CONTINUE outside of loop BREAK或CONTINUE超出循环Cannot add or subtract relocatable symbols不能增加或减少可重置的符号Cannot assign to a read-only property不能指定只读属性Cannot BREAK,CONTINUE or EXIT out of a FINALLY clause超出FINALLY子句的范围,不能使用BREAK,CONTINUE或EXIT语句Cannot initialize local variables不能初始化局部变量Cannot initialize multiple variables不能初始化多个变量Cannot initialize thread local variables不能初始化线程局部变量Cannot override a static method不能覆盖静态方法Cannot read a write-only property不能读取只写属性Case label outside of range of case expression CASE标号超出了CASE表达式的范围Circular unit reference to对单元循环引用Class already has a default property类已具有默认的属性Class does not have a default property类没有默认的属性Class or object types only allowed in type section在类型区段只允许有类或对象类型Class type required需要类类型Close error on文件关闭错误Compile terminated by user用户中止编译Constant expected要求常量Constant expression expected要求常量表达式Constant expression violates subrange bounds常量表达式超出子界范围Constant object cannot be passed as var parameter常量对象不能作为变量参数传递Constant or type identifier expected要求常量或类型标识符Constants cannot be used as open array arguments常量不能用作打开数组参数Constructing instance of''containing abstract methods构造的实体包含抽象的方法Could not compile used unit''不能用单元编译Could not create output file不能建立输出文件Could not load RLINK32.DLL不能加载RLINK32.DLLData type too large:exceeds2GB数据类型太大:超过2GBDeclaration of differs from previous declaration的说明与先前的说明不同Default property must be an array property默认的属性必须为数组属性Default values must be of ordinal,pointer or small set type默认的值必须为序数、指针或小集类型Destination cannot be assigned to目标不能指定Destination is inaccessible目标不能存取Dispid''already used by''DISPID标识号已被使用Dispid clause only allowed in OLE automation section DISPID子句只能在OLE自动区段中使用Division by zero除数为零Duplicate case label CASE标号重复Duplicate tag value重复的标志值Dynamic method or message handler not allowed here这里不允许有动态方法或信息处理程序Dynamic methods and message handlers not allowed in OLE automation section在OLE自动区段不允许有动态方法或消息处理程序Element0inaccessible-use'Length'or'SetLength'元素0不能存取-使用LENGTH或SETLENGTHError in numeric constant数值常量错误EXCEPT or FINALLY expected要求EXCEPT或FINALLYEXPORTS allowed only at global scope EXPORTS只允许在全局范围使用Expression has no value表达式没有值Expression too complicated表达式太复杂Field definition not allowed in OLE automation section在OLE自动区段中不允许域定义Field definition not allowed after methods or properties在方法或属性后不允许域定义Field or method identifier expected要求域或方法标识符File not found:文件没有找到File type not allowed here这儿不允许文件类型For loop control variable must be simple local variable FOR循环控制变量必须为简单局部变量For loop control variable must have ordinal type FOR循环控制变量必须为序数类型FOR or WHILE loop executes zero times-deleted FOR或WHILE循环执行零次-删除FOR-Loop variable''cannot be passed as var parameter FOR循环变量不能作为参数传递FOR-Loop variable''may be undefined after loop在循环后的FOR循环变量是不确定的Function needs result type函数需要结果类型Identifier redeclared:''标识符重复说明Illegal character in input file:''($)在输入文件中的非法字符''Illegal message method index非法的消息方法指针Illegal reference to symbol''in object file''在对象文件中对符号的非法引用Illegal type in OLE automation section:''在OLE自动区段中的非法类型Illegal type in Read/Readln statement在Read/Readln语句中的非法类型Illegal type in Write/Writeln statement在Write/Writeln语句中的非法类型Inaccessible value不可存取的值Incompatible types:''and''不兼容的类型和Incompatible types:不兼容的类型Inline assembler stack overflow内联汇编溢出Inline assembler syntax error内联汇编语法错误Instance variable''inaccessible here实体变量在这里不能存取Integer constant or variable name expected要求整形常量或变量名Integer constant too large整型常量太大Internal error:内部错误Invalid pointer operation无效的指针（地址）操作，在使用数组或调用dll 时可能遇到，原因可能是地址分配不够，比如要遍历五个数，只分配了四个地址。

遇到的编程上的困难用英语作文Encountering Difficulties in ProgrammingIn the field of programming, I have encountered numerous challenges that have tested my skills and problem-solving abilities. These difficulties have often pushed me to think critically and find innovative solutions. In this essay, I will discuss some of the most significant programming challenges I have faced and how I have overcome them.One of the common difficulties I have encountered is debugging code. Debugging is an essential part of programming, but it can be time-consuming and frustrating. When faced with a bug, I have learned to approach the problem systematically.I start by understanding the error message or unexpected behavior that occurs. Then, I carefully review the code, checking for syntax errors, logical flaws, or incorrect variable assignments. If the bug is not apparent, I use tools like print statements or debugging software to track the program's execution and identify the issue. Patience and persistence are crucial in this process, as it may require multiple iterations to locate and fix the bug.Another challenge I have faced is understanding complex algorithms and data structures. Programming often involves implementing intricate algorithms or utilizing advanced data structures to optimize performance. To overcome this difficulty, I dedicate time to studying and researching these concepts. I read textbooks, watch online tutorials, and participate in coding competitions to enhance my understanding. Additionally, I practice implementing these algorithms in small projects to gain hands-on experience. Breaking down complex algorithms into smaller, manageable parts and analyzing their time and space complexities has been instrumental in my learning process.Working on large-scale projects with a team has also presented its own set of challenges. Collaborating with others requires effective communication and coordination. Miscommunication or differences in coding styles can lead to conflicts and delays. To address this, I make a conscious effort to maintain clear and open lines of communication with my team members. Regular meetings, code reviews, and documentation help ensure that everyone is on the same page. Additionally,I have learned to be adaptable and flexible, considering different perspectives and incorporating feedback from team members. This collaborative approach has not only improved the quality of the projects but also fostered a positive and productive working environment.Lastly, staying updated with the rapidly evolving programming languages, frameworks, and tools can be overwhelming. New technologies are constantly emerging, and it can be challenging to keep up with the latest trends. To overcome this difficulty, I prioritize continuous learning. I follow industry blogs, attend webinars, and participate in online courses to stay updated with the latest advancements. Moreover, I engage in personal projects that allow me to experiment with new technologies and expand my skill set. By embracing a growth mindset and being proactive in my learning, I can adapt to new technologies and remain competitive in the programming field.虽然在编程领域中遇到了许多困难，但我通过不断的学习和实践，克服了这些困难。

探究 Java 中“未知常量标签 0 在类文件中”的错误提示在 Java 开发过程中，有时候我们会遇到“未知常量标签 0 在类文件中”的错误提示，这让许多开发者感到困惑。

本文将深入探讨这个错误提示的原因、影响以及解决方法。

下面是本店铺为大家精心编写的4篇《探究 Java 中“未知常量标签 0 在类文件中”的错误提示》，供大家借鉴与参考，希望对大家有所帮助。

《探究 Java 中“未知常量标签 0 在类文件中”的错误提示》篇1一、错误提示的概述在 Java 开发过程中，当我们尝试运行某个程序时，有时候会遇到如下错误提示:```Exception in thread "main" ng.Error: Unknown constant tag 0 in class fileat ng.ClassLoader.defineClass1(Native Method)atng.ClassLoader.defineClass(ClassLoader.java:760)atjava.security.SecureClassLoader.defineClass(SecureClassLoad er.java:142)at.URLClassLoader.defineClass(URLClassLoader.java:473 )at.URLClassLoader.access$100(URLClassLoader.java:74) at.URLClassLoader$1.run(URLClassLoader.java:365)at.URLClassLoader$1.run(URLClassLoader.java:361)at java.security.AccessController.doPrivileged(Native Method)at.URLClassLoader.findClass(URLClassLoader.java:360) atng.ClassLoader.loadClass(ClassLoader.java:424)atuncher$AppClassLoader.loadClass(Launcher.java:33 5)atng.ClassLoader.loadClass(ClassLoader.java:357)at ng.Class.forName0(Native Method)at ng.Class.forName(Class.java:270)at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)atsun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAcc essorImpl.java:62)atsun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingM ethodAccessorImpl.java:43)at ng.reflect.Method.invoke(Method.java:498)atuncherHelper$FXHelper.main(LauncherHelper.ja va:767)```其中，“未知常量标签 0 在类文件中”的错误提示让我们感到困惑。

throttle_classes 限流方法限流（throttling）是一种用于控制服务访问频率的方法，主要用于保护系统免受流量过载和滥用的影响。

在实际应用中，有许多不同的限流方法可以实现限制某个操作或服务的请求次数或频率。

1. 固定窗口算法（Fixed Window Algorithm）：这是一种简单的限流方法，它根据固定的时间窗口大小限制请求的数量。

例如，在一分钟的时间窗口内，最多允许十个请求。

这种方法的缺点是可能发生突发请求，在时间窗口内的前半部分有很多请求，而后半部分却几乎没有请求的情况。

2. 滑动窗口算法（Sliding Window Algorithm）：这种方法解决了固定窗口算法的不足之处，它将时间窗口分成多个小的时间段，并跟踪每个时间段内的请求数量。

例如，在一分钟内，将时间窗口分为6个10秒的小窗口，每个小窗口内最多允许两个请求。

这样，即使在时间窗口的前半部分有很多请求，后半部分也可以平衡请求的数量。

3. 漏桶算法（Leaky Bucket Algorithm）：这是一种常用的限流方法，它使用一个漏桶来控制请求的速率。

漏桶有一个固定的容量，请求被添加到漏桶中，然后以固定的速率从漏桶中取出处理。

如果漏桶已满，新的请求将被拒绝。

这种方法可以平滑请求的速率，并防止流量过载。

4. 令牌桶算法（Token Bucket Algorithm）：类似于漏桶算法，令牌桶算法也使用一个桶来控制请求的速率。

但是，与漏桶不同的是，令牌桶在桶中放置了一定数量的令牌，每个令牌代表一个请求的许可。

请求需要从桶中获取一个令牌才能被处理，如果桶中没有令牌，则请求被拒绝。

这种方法能够限制请求的数量和速率。

以上只是一些常见的限流方法，实际上还有很多其他的限流算法和实现方式，可以根据具体的需求和场景选择合适的方法。

BIOLOGICAL IDENTIFICATIONS THROUGH DNA BARCODES Paul D.N. HebertAlina CywinskaShelley L. BallJeremy R. deWaardDepartment of ZoologyUniversity of GuelphGuelph, ON N1G 2W1CanadaABSTRACTAlthough much biological research depends upon species diagnoses, taxonomic expertise is collapsing. We are convinced that the sole prospect for a sustainable identification capability lies in the construction of systems that employ DNA sequences as taxon ‘barcodes’. In this study, we establish that the mitochondrial gene, cytochrome c oxidase I (COI), can serve as the core of a global bioidentification system for animals. We show firstly that COI profiles, derived from the low-density sampling of higher taxonomic categories, ordinarily assign newly analyzed taxa to the appropriate phylum or order. We subsequently demonstrate that species-level assignments can be obtained by creating comprehensive COI profiles. A model COI profile, based upon the analysis of a single individual from each of 200 closely allied species of lepidopterans, was 100% successful in correctly identifying subsequent specimens. When fully developed, a COI identification system will provide a reliable, cost-effective and accessible solution to the current problems of species identification. Its assembly will also generate important new insights concerning the diversification of life and the rules of molecular evolution.INTRODUCTIONThe diversity of life underpins all biological studies, but it is also a harsh burden. Whereas physicists deal with a cosmos assembled from 12 fundamental particles, biologists confront a planet populated by millions of species. Their discrimination is no easy task. In fact, since few taxonomists can critically identify more than 0.01% of the estimated 10-15 million species (Hammond 1992, Hawksworth and Kalin-Arroyo 1995), a community of 15,000 taxonomists will be required in perpetuity to identify life if our reliance on morphological diagnosis is sustained. Moreover, this approach to the task of routine species identification has four significant limitations. Firstly, both phenotypic plasticity and genetic variability in the characters employed for species recognition can lead to incorrect identifications. Secondly, this approach overlooks morphologically cryptic taxa that are common in many groups (Knowlton 1993, Jarman and Elliot 2000). Thirdly, since morphological keys are often only effective for a particular life stage or gender, many individuals cannot be identified. Finally, although modern interactive versions represent a major advance, the use of keys often demands such a high level of expertise that misdiagnoses are common.The limitations inherent in morphology-based identification systems and the dwindling pool of taxonomists signal the need for a new solution to taxon recognition. Microgenomic identification systems, which permit life’s discrimination through the analysis of a small segment of the genome, represent one extremely promising approach to the diagnosis of biological diversity. This concept has already gained broad acceptance among those working with the least morphologically tractable groups such as viruses,bacteria and protists (Nanney 1982, Pace 1997, Allander et al. 2001, Hamels et al. 2001). However, the problems inherent in morphological taxonomy are general enough to motivate the diffusion of this approach to all life. In fact, there are a growing number of cases in which DNA-based identification systems have been applied to higher organisms (Brown et al. 1999, Bucklin et al. 1999, Trewick 2000, Vincent et al. 2000) Genomic approaches to taxon diagnosis exploit diversity among DNA sequences to identify organisms (Kurtzman 1994, Wilson 1995). In a very real sense, these sequences can be viewed as genetic ‘barcodes’ that are embedded in every cell. When one considers the discrimination of life’s diversity from a combinatorial perspective, it isa modest problem. The Universal Product Codes, used to identify retail products, employ10 alternate numerals at 11 positions to generate 100 billion unique identifiers. Genomic barcodes have only four alternate nucleotides at each position, but the string of sites available for inspection is huge. The survey of just 15 of these nucleotide positions creates the possibility of 4 15 (1 billion) codes, a 100-fold excess beyond that required to discriminate life if each taxon was uniquely branded. However, the survey of nucleotide diversity needs to be more comprehensive because functional constraints hold some nucleotide positions constant and intraspecific diversity exists at others. The impact of functional constraints can be reduced by focusing on a protein-coding gene, given that most shifts at the third nucleotide position of codons are weakly constrained by selection because of their four-fold degeneracy. Hence, by examining any stretch of 45 nucleotides, one gains access to 15 sites weakly impacted by selection and, therefore, 1 billion possible identification labels. In practice, there is no need to constrain analysis tosuch short stretches of DNA because sequence information is easily obtained for DNA fragments hundreds of base pairs long. This ability to inspect longer sequences is significant, given two other biological considerations. Firstly, nucleotide composition at third position sites is often strongly biased (A-T in arthropods, C-G in chordates), reducing information content. However, even if the A-T or C-G ratio reached 1, the inspection of just 90 bp would recover the prospect of 1 billion alternates (2 30 = 4 15 ). A second constraint derives from the limited utilization of this potential information capacity, since most nucleotide positions are unchanged in comparisons involving closely related species. However, given a modest rate (e.g. 2% per million years) of sequence change, one expects 12 diagnostic nucleotide differences in a 600bp comparison between species with just a million year history of reproductive isolation. As both the fossil record and prior molecular analyses suggest that most species persist for millions of years, the likelihood of taxon diagnosis is high. There is, however, no simple formula that can predict the length of sequence that must be analyzed to ensure species diagnosis because rates of molecular evolution vary among different segments of the genome and among taxa. Obviously, the analysis of rapidly evolving gene regions or taxa will aid the diagnosis of lineages with brief histories of reproductive isolation, while the reverse will be true for rate decelerated genes or species.Although there has never been an effort to implement a microgenomic identification system on a large scale, enough work has been done to indicate key design elements. It is clear that the mitochondrial (mt) genome of animals represents a better target for analysis than the nuclear genome because of its lack of introns, its limitedexposure to recombination and its haploid mode of inheritance (Saccone et al. 1999). As well, robust primers enable the routine recovery of specific segments of the mt genome (Folmer et al. 1994, Simmons and Weller 2001). Past phylogenetic work has often focused on mitochondrial genes encoding ribosomal (12S, 16S) DNA, but their utility in broad taxonomic analyses is constrained by the prevalence of insertions and deletions (indels) that greatly complicate sequence alignments (Doyle and Gaut 2000). The 13 protein-coding genes in the animal mt genome are better targets because indels are rare since most lead to a shift in the reading frame. There is no compelling a priori reason to focus analysis on a specific gene, but the cytochrome c oxidase I gene (COI) does have two important advantages. Firstly, the universal primers for this gene are very robust, enabling recovery of its 5’ end from representatives of most, if not all, animal phyla (Folmer et al. 1994, Zhang and Hewitt 1997). Furthermore, COI appears to possess a greater range in phylogenetic signal than any other mitochondrial gene. In common with other protein-coding genes, its third position nucleotides show a high incidence of base substitutions, leading to a rate of molecular evolution that is about 3x greater than that of 12S or 16S rDNA (Knowlton and Weigt 1998). In fact, the evolution of this gene is not only rapid enough to allow the discrimination of closely allied species, but even phylogeographic groups within single species (Cox and Hebert 2001, Wares and Cunningham 2001). Although COI may be matched by other mt genes in resolving such cases of recent divergence, this gene is more likely to provide deeper phylogenetic insights than alternatives such as cytochrome b (Simmons and Weller 2001) because changes in its amino acid sequence occur more slowly than those in this or any othermitochondrial gene (Lynch and Jarrell 1993). As a result, by examining amino acid substitutions, it may be possible to assign any unidentified organism to a higher taxonomic group (e.g. phylum, order), before examining nucleotide substitutions to determine its species identity.This study evaluates the potential of COI as a taxonomic tool. We first created a COI ‘profile’ for the seven most diverse animal phyla, based on the analysis of 100 representative species, and subsequently show that this baseline information assigned 96% of newly analyzed taxa to their proper phylum. Next we examined the Class Hexapoda, a group selected because it represents the greatest concentration of biodiversity on the planet (Novotny et al 2002). We created a COI ‘profile’ for 8 of the most diverse orders of insects, based on a single representative from 100 different families, and show that this ‘profile’ assigned each of 50 newly analyzed taxa to its correct order. Finally, we tested the ability of COI sequences to correctly identify species of lepidopterans, a group targeted for analysis because sequence divergences are low among families in this order. As such, the lepidopterans provide a challenging case for species diagnosis, especially since this is one of the most speciose orders of insects. This test, which involved creating a COI ‘profile’ for 200 closely allied species and subsequently using it to assign 150 newly analyzed individuals to a species, revealed 100% success in identification.`MATERIALS AND METHODSSequencesApproximately one-quarter of the COI sequences (172 of 655) used in this study were obtained from GenBank. The rest were obtained by preparing a 30 u l total DNA extract from small tissue samples using the Isoquick (Orca Research, 1997) protocol. The primer pair LCO1490 (5’-ggtcaacaaatcataaagatattgg-3’) and HCO2198 (5’-taaacttcagggtgaccaaaaaatca-3’) was subsequently used to amplify a 658 bp fragment of the COI gene (Folmer et al 1994). Each polymerase chain reaction contained 5 u l 10X PCR buffer pH 8.3 (10 mM Tris HCl pH 8.3, 1.5 mM MgCl2, 50 mM KCl, 0.01% NP-40), 35 u l distilled water, 200 u M of each dNTP, 1 unit of Taq polymerase, 0.3 u M of each primer and 1-4 u l of DNA template. The PCR thermal regime consisted of 1 cycle of 1 min at 94o C; five cycles of 1 min at 94o C, 1.5 min at 45o C and 1.5 min at 72o C; 35 cycles of 1 min at 94o C, 1.5 min at 50o C and 1 min at 72o C followed by a final cycle of 5 min at 72o C. Each PCR product was subsequently gel purified using the Qiaex II kit (Qiagen) and sequenced in one direction on an ABI 377 automated sequencer (Applied Biosystems) using the Big Dye v. 3 sequencing kit. All sequences obtained in this study have been submitted to GenBank.COI ProfilesWe created three COI profiles, one for the 7 dominant phyla of animals, another for 8 of the largest orders of insects and the last for 200 closely allied species of lepidopterans.These profiles were designed to provide an overview of COI diversity within each taxonomic assemblage and were subsequently used as the basis for identifications to the phylum, ordinal or species level by determining the sequence congruence between each ‘unknown’ taxon and the species included in a particular profile.The phylum profile included 100 COI sequences, all obtained from GenBank (Appendix 1). To ensure broad taxonomic coverage, each sequence was derived from a different family and representatives were included from all available classes. Ten sequences were obtained for each of the five phyla (Annelida, Chordata, Echinodermata, Nematoda, Platyhelminthes) that include from 5,000-50,000 species, while 25 sequences were collected for both phyla (Arthropoda, Mollusca) with more than 100,000 species.The ordinal profile was created by obtaining COI sequences from a single representative of 100 insect families (Appendix 2). The four most diverse orders (> 100,000 described species) of insects were selected for analysis, together with four additional orders chosen randomly from among the 15 insect orders (Gaston and Hudson 1994) with medium diversity (1,000-15,000 described species). From 10-25 families were examined for each of the four most diverse orders (Coleoptera, Diptera, Hymenoptera, Lepidoptera), while 4-10 families were examined for the other orders (Blattaria, Ephemeroptera, Orthoptera, Plecoptera).The species profile was based upon COI data for a single individual of the 200 commonest lepidopteran species from a site near Guelph, ON (Appendix 3). This profile examined members of just three allied superfamilies (Geometroidea, Noctuoidea, Sphingoidea) to determine the lower limits on COI divergence in an assemblage ofclosely related species. The Noctuoidea included members of three families (Arctiidae, Noctuidae, Notodontidae) while the others included representatives of just a single family (Geometridae, Sphingidae).Test TaxaAdditional sequences were collected to test the ability of each profile to assign newly analyzed species to a taxonomic category (Appendices 1-3). COI sequences were obtained from 55 ‘test’ taxa to assess the success of the phylum profile in assigning newly analyzed species to a phylum. These ‘test’ taxa included 5 representatives from each of the 5 ‘small’ phyla, and 15 representatives from both the Mollusca and the Arthropoda. When possible, the ‘test’ taxa belonged to families that were not included in the phylum profile. A similar approach was employed in testing the ability of the ordinal profile to classify newly analyzed insects to an order. Fifty new taxa were examined, including 1-5 representatives from each small order and 5-10 representatives from each of the four large orders. When possible, the ‘test’ taxa belonged to families or genera that were not included in the ordinal profile. A test of the species profile required a slightly different approach, as identifications were only possible for species represented in it. As a result, sequences were obtained from another 150 individuals belonging to the species included in this profile.Data AnalysisSequences were aligned in the SeqApp 1.9 sequence editor. They were subsequently pruned to 669 bp for the phylum analysis, to 624 bp for the ordinal analysis and to 617 bp for the species level analysis. Analyses at the ordinal and phylum levels examined amino acid divergences, using Poisson corrected p-distances, to reduce the impacts of homoplasy. For the species-level analysis, nucleotide sequence divergences were calculated using the Kimura-2-Parameter (K2P) model, the best metric when distances are low (Nei and Kumar 2000) as in this study.Neighbour-Joining analysis, implemented in MEGA2.1 (Kumar et al. 2001), was employed to both examine relationships among taxa in the profiles and for the subsequent classification of ‘test’ taxa because of its strong track record in the analysis of large species assemblages (Kumar and Gadagkar 2000). This approach has the additional advantage of generating results much more quickly than alternates. The NJ profiles for both the orders and phyla possessed 100 terminal nodes, each representing a species from a different family, while the species NJ profile had 200 nodes, each representing a different lepidopteran species. A member of the primitive insect order Thysanura (Family Lepismatidae) was used as the outgroup for the insect profile, while single members of three primitive lepidopteran families were employed as the outgroup for the species profile.Each of the three (phylum, order, species) NJ profiles was subsequently used as a classification engine, by rerunning the analysis following the repeated addition of a single ‘test’ taxon to the data set. Following each analysis, the ‘test’ species was assignedmembership in the same taxonomic group as its nearest neighboring node. For example, in the ordinal analysis, a ‘test’ taxon was identified as a member of the order Lepidoptera if it grouped most closely with any one of the 24 lepidopteran families included in the profile. The success of classification was quantified for both the phylum and ordinal level analyses by determining the proportion of ‘test’ taxa assigned to the proper phylum/order. In the case of species, a stricter criterion was employed. A ‘test’ taxon was recognized as being correctly identified only if its sequence grouped most closely with the single representative of its species in the profile.Multidimensional scaling (MDS), implemented in Systat 8.0, was employed to provide a graphical summary of the species-level results because of the very large number of taxa. MDS explores similarity relationships in Euclidean space and has the advantage of permitting genetically intermediate taxa to remain spatially intermediate, rather than forcing them to cluster into a pseudogroup as in hierarchical methods (Lessa 1990). In the present case a similarity matrix was constructed by treating every position in the alignment as a separate character and ambiguous nucleotides as missing characters. The sequence information was coded using dummy variables (A=1, G=2, C=3, T=4). However, as noted earlier, a NJ profile was also constructed for the lepidopteran sequences using K2P distances and this is provided in Appendix 4.RESULTSTaxon ProfilesEach of the 100 species included in the phylum and ordinal profiles possessed a different amino acid sequence at COI. The phylum profile revealed good resolution of the major taxonomic groups (Figure 1). Monophyletic assemblages were recovered for three phyla (Annelida, Echinodermata, Platyhelminthes) and the chordate lineages formed a cohesive group. Members of the Nematoda were separated into three groups, but each corresponded to one of the three subclasses that comprise this phylum. Twenty-three of the 25 arthropods formed a monophyletic group, but the sole representatives of two crustacean classes (Cephalocarida, Maxillopoda) fell outside this group. Twelve of the 25 molluscan lineages formed a monophyletic assemblage allied to the annelids, but the others were separated into groups that showed marked genetic divergence. One group consisted solely of cephalopods, a second was largely pulmonates, and the rest were bivalves. It is worth emphasizing that these outlying COI sequences always showed a large level of amino acid divergence from sequences possessed by other taxonomic groups. As such, the rate acceleration in these lineages generated novel COI amino acid sequences rather than secondary convergence on the amino acid arrays of other groups.The ordinal profile showed high cohesion of taxonomic groups as 7 of the 8 orders formed monophyletic assemblages (Figure 2). The sole exception involved the Coleoptera whose members were partitioned into three groups. Two of these groups included 21 families belonging to the very diverse suborder Polyphaga, while the other group included 4 families belonging to the suborder Adephaga. Among the four majororders, species of Diptera and Lepidoptera showed much less variation in their amino acid sequences than did the Hymenoptera, while the Coleoptera showed an intermediate level of divergence (Table 1).Each of the 200 lepidopterans included in the species profile possessed a distinct COI sequence. Moreover, a MDS plot showed that species belonging to the three superfamilies fell into distinct clusters (Figure 3), signaling their genetic divergence. A detailed inspection of the NJ tree (Appendix 4) revealed further evidence for the clustering of taxonomically allied species. For example, 23 genera were represented by two species and these formed monophyletic pairs in 18 cases. Similarly, 5 of the 6 genera represented by three species formed monphyletic assemblagesTesting Taxonomic AssignmentsFifty three of the 55 ‘test’ species (96.3%) were assigned to the correct phylum in the analyses at this level (Table 2). The exceptions involved a polychaete annelid that grouped most closely with a mollusc and a bivalve that grouped with one of the arthropod outliers. However, in both cases, there was substantial sequence divergence (13%, 25%) between the test taxon and the lineage in the profile that was most similar to it. Identification success at the ordinal-level was 100% as all 50 insect species were assigned to the correct order. Moreover, when a ‘test’ species belonged to a family represented in the ordinal profile, it typically grouped most closely with it. Identification success at the species-level was also 100%, as each of the 150 ‘test’ individuals clustered most closely with the representative of its species in the profile. The sequences in thespecies profile were subsequently merged with those from the ‘test’ taxa to allow a more detailed examination of the factors enabling successful classification (Appendix 5). MDS analysis (Figure 4) showed that ‘test’ taxa were always either genetically identical or most closely associated to the representative of their species in the profile. Examination of the genetic distance matrix quantified this fact, showing that divergences between conspecific individuals were always small, averaging 0.25% (Table 3). By contrast, sequence divergences between species were much greater, averaging 6.8% for congeneric taxa and higher for more distantly related taxa (Table 3). A few species pairs showed lower values, but only 4 of the 19,900 pairwise comparisons showed divergences that were less than 3%. Figure 4a shows one of these cases, involving two species of Hypoprepia, but, even in these situations, there were no shared sequences between taxa.DISCUSSIONThis study establishes the feasibility of developing a COI-based identification system for animals-at-large. PCR products were recovered from all species and there was no evidence of the nuclear pseudogenes that have complicated some studies employing degenerate COI primers (Williams and Knowlton 2001). Moreover, the alignment of COI sequences was straightforward, as insertion and deletion events were uncommon, reinforcing the results of earlier work showing the rarity of indels in this gene (Mardulyn and Whitfield 1999). Aside from their ease of acquisition and alignment, the COI sequences possessed, as expected, a high level of diversity.We showed that differences in COI amino acid sequences were sufficient to enable the reliable assignment of organisms to higher taxonomic categories. It is worth emphasizing that most newly analyzed taxa were placed in the correct order or phylum despite the fact that our profiles were based on a tiny fraction of the member species. For example, our ordinal profile, which was based on just 0.002% of the total species in these orders, led to 100% identification success. The two misidentifications at a phylum level were undoubtedly a consequence of the limited size and diversity of our phylum profile. The misplaced polychaete belonged to an order that was not in the profile, while the misidentified mollusc belonged to a subclass that was represented in the profile by just a single species. Such cases of misidentification would not occur in profiles that more thoroughly surveyed COI diversity among members of the target assemblage. The general success of COI in recognizing relationships among taxa in these cases is important because it signals that character convergence or horizontal gene transfer (i.e. via retroviruses) have not disrupted the recovery of expected taxon affinities. Moreover, it establishes that the information content of COI is sufficient to enable the placement of organisms in the deepest taxonomic ranks.The gold standard for any taxonomic system is its ability to deliver accurate species identifications. Our COI species profile provided 100% success in the identification of lepidopteran species and we expect similar results in other groups, since the Lepidoptera are one of the most taxonomically diverse orders of animals and they show low sequence divergences. There is also reason to expect successful diagnosis at other locales, as the species richness of lepidopterans at the study site exceeds that whichwill be encountered in regional surveys of most animal orders. Higher diversities will be encountered for some orders in tropical settings (Godfray et al. 1999), but COI diagnoses should not fail at these sites unless species are unusually young.COI-based identification systems can also aid the initial delineation of species. For example, inspection of the genetic distance matrix for lepidopterans indicated that divergence values between species were ordinarily greater than 3%. In fact, when this value was employed as a threshold for species diagnosis, it led to the recognition of 196 of the 200 (97.6%) species recognized through prior morphological study. The exceptions involved four congeneric species pairs that were genetically distinct, but showed low (0.6-2.0%) divergences, suggesting their recent origin. The general ease of species diagnosis reveals one of the great values of a DNA-based approach to identification. Newly encountered species will ordinarily signal their presence by their genetic divergence from known members of the assemblage.The prospect of using a standard COI threshold to guide species diagnosis in situations where prior taxonomic work has been limited is appealing. It will, however, be important to validate this approach by determining the thresholds that distinguish species in other geographic regions and taxonomic groups. Thresholds will particularly need to be established for groups with differences in traits, such as generation length or dispersal regime, which are likely to alter rates of molecular evolution or the extent of population subdivision. However, differences in thresholds may be smaller than might be expected. For example, different species of vertebrates ordinarily show more than 2% sequencedivergence at cytochrome b (Avise and Walker 1999), a value close to the 3% COI threshold adopted for lepidopterans in this study.The likely applicability of a COI identification system to new animal groups and geographic settings suggests the feasibility of creating an identification system for animals-at-large. Certainly, existing primers enable recovery of this gene from most, if not all, animal species and its sequences are divergent enough to enable recognition of all but the youngest species. It is, of course, impossible for any mitochondrially–based identification system to fully resolve the complexity of life. Where species boundaries are blurred by hybridization or introgression, supplemental analyses of one or more nuclear genes will be required. Similarly, when species have arisen through polyploidization, determinations of genome size may be needed. While protocols will be required to deal with such complications, a COI-based identification system will undoubtedly provide taxonomic resolution that exceeds that which can be achieved through morphological studies. Moreover, the generation of COI profiles will provide a partial solution to the thinning ranks of morphological taxonomists by enabling a crystallization of their knowledge before they leave the field. As well, since COI sequences can be obtained from museum specimens without their destruction, it will be possible to regain taxonomic capability, albeit in a novel format, for groups which currently lack an authority.We believe that a COI database can be developed within 20 years for the 5-10M animal species on the planet (Hammond 1992, Novotny et al 2002) for about one billion dollars, far less than that directed to other major science initiatives such as the Human Genome project or the International Space Station. Moreover, initial efforts could focus。

2020北京昌平初一（上）期末数 学 2020.1一、选择题（本题共8道小题，每小题2分，共16分）下面各题均有四个选项，其中只有一个是符合题意的.1. 2019年10月1日上午盛大的国庆阅兵在天安门广场举行，总规模约为15000人. 阅兵编59个方(梯)队和联合军乐团，各型飞机160余架、装备580台(套)，是近几次阅兵中规模最大的一次.将15000用科学记数法可表示为 A.41.510⨯ B.50.1510⨯ C.51.510⨯ D.31510⨯2. 一个几何体的表面展开图如图所示，这个几何体是 A.正方体 B.三棱锥 C.四棱锥 D.圆柱3. 下列等式变形正确的是A. 如果a ＝b ，那么a +3＝b －3B. 如果3a －7＝5a ，那么3a +5a ＝7C. 如果3x ＝－3，那么6x ＝－6D. 如果2x ＝3，那么x ＝234. 有理数a ，b 在数轴上对应点的位置如图所示，下列说法中正确的是 A. a ＞bB. ﹣a ＞bC.a b＞ D. a +b ＞05. 下列运算正确的是A. m 2+m 3=m 5B. 3m 2－m 2=2mC. 3m 2n －m 2n ＝2m 2nD. m +n=mn6. 已知|m －3|+(n +2)2=0，则m +2n 的值为A. -1B. 1C. 4D. 70ab7. 在2019年世界杯上，中国女排最终以11战全胜积32分的成绩成功卫冕.比赛的积分规则为：比赛中以3-0或者3-1取胜的球队积3分、负队积0分，在比赛中以3-2取胜的球队积2分、负队积1分.某队以3-1胜了a 场，以3-2胜了b 场，以2-3负了c 场，则该队的积分可表示为A . 3a +2b +c B. 3a +2b C.3a +3b +cD.3a +3b8. 下图是昌平区2019年1月份每天的最低和最高气温，观察此图，下列说法正确的是A. 在1月份中，最高气温为10℃，最低气温为－2℃B. 在10号至16号的气温中，每天温差最小为7℃C. 每天的最高气温均高于0℃，最低气温均低于0℃D. 每天的最高气温与最低气温都是具有相反意义的量 二、填空题（本题共8道小题，每小题2分，共16分） 9. －5的相反数是___________.10. 单项式－2x 2y 的系数是 ，次数是 . 11. 如图，已知∠AOC =50°30′，∠BOC =14°18′，则∠AOB ＝ ° ′12. 如果2x =是关于x 的方程213x m +=的解，那么m 的值是 .13. 一件商品的标价是100元，进价是50元，打八折出售后这件商品的利润是_______元.14. 如图，在四边形ABCD 内找一点O ，使它到四边形四个顶点的距离之和OA +OB +OC +OD 最小，正确的作法是连接AC 、BD 交于点O ，则点O 就是要找的点，请你用所学过的数学知识解释这一道理__________________________.昌平1月份气温变化趋势（日期）（温度）50COBA15. 代数式kx +b 中，当x 取值分别为－1,0,1,2时，对应代数式的值如下表：则k +b = .16. 在∠AOB 中，C ，D 分别为边OA ，OB 上的点（不与顶点O 重合）. 对于任意锐角∠AOB ，下面三个结论中，① 作边OB 的平行线与边OA 相交，这样的平行线能作出无数条； ② 连接CD ，存在∠ODC 是直角；③ 点C 到边OB 的距离不超过线段CD 的长. 所有正确结论的序号是 .三、解答题（本题共12道小题，第17-22题，每小题5分，第23-26题，每小题6分，第27、28题，每小题7分，共68分）17.计算：7(3)10(16)-+---- 18.计算：⎪⎭⎫⎝⎛-⨯÷-41855.2.19.计算：()411293⎛⎫-+-÷--- ⎪⎝⎭20.计算：(2－a 2+4a)－(5a 2－a －1)21.解方程：5x +3＝2(x －3) 22.解方程：21123x x +--=23. 如图: A ，B ，C 是平面上三个点，按下列要求画出图形. （1）作直线BC ，射线AB ，线段AC .（2）取AC 中点D ，连接BD ，量出∠ACB 的度数(精确到个位）. （3）通过度量猜想BD 和AC 的数量关系.CBA24.列方程解应用题举世瞩目的2019年中国北京世界园艺博览会在长城脚下的北京延庆开园，它给人们提供了看山、看水、看风景的机会.一天小龙和朋友几家去延庆世园会游玩，他们购买普通票比购买优惠票的数量少5张，买票共花费了1400元，符合他们购票的条件如下表，请问他们买了多少张优惠票？25．如图：O 是直线AB 上一点，∠AOC ＝50°,OD 是∠BOC 的角平分线，OE ⊥OC 于点O .求∠DOE 的度数.（请补全下面的解题过程） 解：∵O 是直线AB 上一点，∠AOC ＝50°， ∴∠BOC ＝180°－∠AOC ＝ °. ∵ OD 是∠BOC 的角平分线，∴∠COD ＝ ∠BOC .( ) ∴∠COD ＝65°.∵OE ⊥OC 于点O ，（已知）.∴∠COE ＝ °.( ) ∴∠DOE ＝∠COE －∠COD ＝ ° . 26.已知线段AB ，点C 在直线AB 上，D 为线段BC 的中点.（1）若AB ＝8 ，AC ＝2，求线段CD 的长.（2）若点E 是线段AC 的中点，直接写出线段DE 和AB 的数量关系是________________.E ODCBABA27.观察下列两个等式：22121133-=⨯⨯-，33222155-=⨯⨯-给出定义如下： 我们称使等式a ﹣b ＝2ab ﹣1成立的一对有理数a ，b 为“同心有理数对”，记为（a ，b ），如：数对（1，23），（2，35），都是“同心有理数对”. （1）数对（﹣2，1），（3，47）是 “同心有理数对”的是__________. （2）若（a ，3）是“同心有理数对”，求a 的值；（3）若（m ，n ）是“同心有理数对”，则（﹣n ，﹣m ） “同心有理数对”（填“是”或“不是”），说明理由.28.如图所示，点A ，B ，C 是数轴上的三个点，其中AB ＝12，且A ，B 两点表示的数互为相反数. (1)请在数轴上标出原点O ，并写出点A 表示的数；(2)如果点Q 以每秒2个单位的速度从点B 出发向左运动，那么经过 秒时，点C 恰好是BQ 的中点； (3)如果点P 以每秒1个单位的速度从点A 出发向右运动，那么经过多少秒时PC ＝2PB .C BA2020北京昌平初一（上）期末数学参考答案一、选择题（本题共8道小题，每小题2分，共16分）二、填空题（本题共8道小题，每小题2分，共16分）三、解答题（本题共12道小题，第17-22题，每小题5分，第23-26题，每小题6分，第27、28题，每小题7分，共68分）17．解：101016=--+原式 ………………………… 2分 2016=+- ………………………… 4分 4=-. ………………………… 5分18．解：581××254⎛⎫=-- ⎪⎝⎭原式 ………………………… 3分1= ………………………… 5分 19．解：()()1239=-+-⨯--原式 ………………………… 3分=169-+- ………………………… 4分 4=- ………………………… 5分20．解：222451a a a a =-+-++原式 ………………………… 3分2653a a =-++. ………………………… 5分 21．解：5326x x +=-.………………………… 2分5263x x -=--.………………………… 3分39x =-. ………………………… 4分3x =-………………………… 5分22．解：3(2)2(1)6x x +--=.………………………… 2分36226x x +-+=.………………………… 3分32626x x -=--.………………………… 4分题号 12345678答案A D C D C A A B题号91011121314 1516答案5-2，364°48′230两点之间线段最短.3①②③2x =-.………………………… 5分23．解：（1）正确作图 ………………………… 3分（2）如图，∠ACB ＝45° ………………………… 5分（3）12BD AC =………………………… 6分 24．解： 设小龙和几个朋友购买了x 张优惠票,根据题意列方程，得： ……… 1分 80x +120（x −5）＝1400 ………………………… 3分 80x +120x −600＝1400 ………………………… 4分 200x ＝2000x ＝10 ………………………… 5分 答：小龙和几个朋友购买了10张优惠票. ………………………… 6分 25.解：（1）130. ………………………… 1分12；角平分线的定义. ………………………… 3分 90；垂直的定义 ………………………… 5分 25. ………………………… 6分 26.解：（1）如图1，当C 在点A 右侧时，∵AB ＝8，AC ＝2.∴BC ＝AB －AC ＝6 ………………………………… 1分 ∵D 是线段BC 的中点 ∴132CD BC == ………………………………… 2分 如图2，当C 在点A 左侧时，图1D CA B图2D C BA∵AB ＝8，AC ＝2.∴BC ＝AB +AC ＝10 ………………………………… 3分 ∵D 是线段BC 的中点 ∴152CD BC == ………………………………… 4分 综上所述CD ＝3或5（2）AB ＝2DE ………………………………… 6分 27．解：（1）437⎛⎫ ⎪⎝⎭，. ………………………………… 2分 （2）∵(a ，3)是“同心有理数对”.∴a －3＝6a －1. ………………………………… 3分 ∴25a =-. ………………………………… 4分 （3）是. ………………………………… 5分 ∵(m ，n)是“同心有理数对”. ∴m －n ＝2mn －1.∴－n －(－m)＝－n +m ＝m －n ＝2mn －1. ………………………………… 7分 ∴(－n ，－m)是“同心有理数对”.28．解：（1）正确标出原点O ，点A 表示的数是-6. ………………………………… 2分 （2）8秒 ………………………………… 4分 （3）设经过t 秒PC ＝2PB.由已知，经过t 秒，点P 在数轴上表示的数是-6+t. ∴PC ＝62t -++＝4t -, 6612PB t t =-+-=-. ∵2PC PB =. ∴4212t t -=-.∴t ＝20或283. ………………………………… 7分。

Angular报错堆栈提⽰说明"Unterminated string literal.": "未终⽌的字符串⽂本。

","Identifier expected.": "应为标识符。

","'{0}' expected.": "应为“{0}”。

","A file cannot have a reference to itself.": "⽂件不能引⽤⾃⾝。

","Trailing comma not allowed.": "不允许使⽤尾随逗号。

","'/' expected.": "应为 "/"。

","Unexpected token.": "意外的标记。

","A rest parameter must be last in a parameter list.": "Rest 参数必须是列表中的最后⼀个参数。

","Parameter cannot have question mark and initializer.": "参数不能包含问号和初始值设定项。

","A required parameter cannot follow an optional parameter.": "必选参数不能位于可选参数后。

","An index signature cannot have a rest parameter.": "索引签名不能包含 rest 参数。

Q1. How could Java classes direct program messages to the system console, but error messages, say to a file?A. The class System has a variable out that represents the standard output, and the variable err that represents the standard error device. By default, they both point at the system console. This how the standard output could be re-directed:Stream st = new Stream(new FileOutputStream("output.txt")); System.setErr(st); System.setOut(st);* Q2. What''s the difference between an interface and an abstract class?A. An abstract class may contain code in method bodies, which is not allowed in an interface. With abstract classes, you have to inherit your class from it and Java does not allow multiple inheritance. On the other hand, you can implement multiple interfaces in your class.* Q3. Why would you use a synchronized block vs. synchronized method?A. Synchronized blocks place locks for shorter periods than synchronized methods.* Q4. Explain the usage of the keyword transient?A. This keyword indicates that the value of this member variable does not have to be serialized with the object. When the class will be de-serialized, this variable will be initialized with a default value of its data type (i.e. zero for integers).* Q5. How can you force garbage collection?A. You can''t force GC, but could request it by calling System.gc(). JVM does not guarantee that GC will be started immediately.* Q6. How do you know if an explicit object casting is needed?A. If you assign a superclass object to a variable of a subclass''s data type, you need to do explicit casting. For example:Object a; Customer b; b = (Customer) a;When you assign a subclass to a variable having a supeclass type, the casting is performed automatically.* Q7. What''s the difference between the methods sleep() and wait()A. The code sleep(1000); puts thread aside for exactly one second. The code wait(1000), causes a wait of up to one second. A thread could stop waiting earlier if it receives the notify() or notifyAll() call. The method wait() is defined in the class Object and the method sleep() is defined in the class Thread.* Q8. Can you write a Java class that could be used both as an applet as well as an application?A. Yes. Add a main() method to the applet.* Q9. What''s the difference between constructors and other methods?A. Constructors must have the same name as the class and can not return a value. They are only called once while regular methods could be called many times.* Q10. Can you call one constructor from another if a class has multiple constructorsA. Yes. Use this() syntax.* Q11. Explain the usage of Java packages.A. This is a way to organize files when a project consists of multiple modules. It also helps resolve naming conflicts when different packages have classes with the same names. Packages access level also allows you to protect data from being used by the non-authorized classes.* Q12. If a class is located in a package, what do you need to change in the OS environment to be able to use it?A. You need to add a directory or a jar file that contains the package directories to the CLASSPATH environment variable. Let''s say a class Employee belongs to a package com.xyz.hr; and is located in the file c:\dev\com\xyz\hr\Employee.java. In this case, you''d need to add c:\dev to the variable CLASSPATH. If this class contains the method main(), you could test it from a command prompt window as follows:c:\>java com.xyz.hr.Employee* Q13. What''s the difference between J2SDK 1.5 and J2SDK 5.0?A.There''s no difference, Sun Microsystems just re-branded this version.* Q14. What would you use to compare two String variables - the operator == or the methodequals()?A. I''d use the method equals() to compare the values of the Strings and the == to check if two variables point at the same instance of a String object.* Q15. Does it matter in what order catch statements for FileNotFoundException and IOExceptipon are written?A. Yes, it does. The FileNoFoundException is inherited from the IOException. Exception''s subclasses have to be caught first.* Q16. Can an inner class declared inside of a method access local variables of this method?A. It''s possible if these variables are final.* Q17. What can go wrong if you replace && with & in the following code:String a=null; if (a!=null && a.length()>10) {...}A. A single ampersand here would lead to a NullPointerException.* Q18. What''s the main difference between a Vector and an ArrayListA. Java Vector class is internally synchronized and ArrayList is not.* Q19. When should the method invokeLater()be used?A. This method is used to ensure that Swing components are updated through the event-dispatching thread.* Q20. How can a subclass call a method or a constructor defined in a superclass?A. Use the following syntax: super.myMethod(); To call a constructor of the superclass, just write super(); in the first line of the subclass''s constructor.** Q21. What''s the difference between a queue and a stack?A. Stacks works by last-in-first-out rule (LIFO), while queues use the FIFO rule** Q22. You can create an abstract class that contains only abstract methods. On the other hand,you can create an interface that declares the same methods. So can you use abstract classes instead of interfaces?A. Sometimes. But your class may be a descendent of another class and in this case the interface is your only option.** Q23. What comes to mind when you hear about a young generation in Java?A. Garbage collection.** Q24. What comes to mind when someone mentions a shallow copy in Java?A. Object cloning.** Q25. If you''re overriding the method equals() of an object, which other method you might also consider?A. hashCode()** Q26. You are planning to do an indexed search in a list of objects. Which of the two Java collections should you use:ArrayList or LinkedList?A. ArrayList** Q27. How would you make a copy of an entire Java object with its state?A. Have this class implement Cloneable interface and call its method clone().** Q28. How can you minimize the need of garbage collection and make the memory use more effective?A. Use object pooling and weak object references.** Q29. There are two classes: A and B. The class B need to inform a class A when some important event has happened. What Java technique would you use to implement it?A. If these classes are threads I''d consider notify() or notifyAll(). For regular classes you can use the Observer interface.** Q30. What accesslevel do you need to specify in the class declaration to ensure that only classes from the same directory can access it?。

JSLint报错翻译“Missing semicolon.” : “缺少分号.”,“Use the function form of \”use strict\”.” : “使⽤标准化定义function.”,“Unexpected space after ‘-’.” : “在’-'后⾯不应出现空格.”,“Expected a JSON value.” : “请传⼊⼀个json的值.”,“Mixed spaces and tabs.”: “空格和TAB重复.”,“Unsafe character.” : “不安全的字符.”,“Line too long.”: “本⾏中的字符超过设定的最⼤长度.”,“Trailing whitespace.”: “本⾏末尾有过多⽆⽤空格.”,“Script URL.” : “脚本URL.”,“Unexpected {a} in ‘{b}’.” : “在 ‘{b}’ 中不该出现 {a}.”,“Unexpected ‘{a}’.” : “不该在此出现’{a}’.”,“Strings must use doublequote.” : “字符串需要⽤双引号”,“Unnecessary escapement.” : “不需要转义”,“Control character in string: {a}.” : “在字符串中出现了Control的字符”,“Avoid .” : “避免 \\”,“Avoid .” : “避免 ”,“Avoid -.” : “避免 -”,“Bad escapement.” : “错误的转义字符”,“Bad number ‘{a}’.” : “错误的数字 ‘{a}’”,“Missing space after ‘{a}’.” : “在’{a}’之后缺少空格”,“Don’t use extra leading zeros ‘{a}’.” : “不要再’{a}’的前⾯⽤多余的0″,“Avoid 0x-. ‘{a}’.” : “避免使⽤ 0x-. ‘{a}’.”,“A trailing decimal point can be confused with a dot ‘{a}’.” : “在’{a}’中使⽤点尾随⼩数点”,“Unexpected comment.” : “不该在此处出现注释”,“Unescaped ‘{a}’.” : “没有转义 ‘{a}’”,“Unexpected control character in regular expression.” : “在正则表达式中出现了control字符”,“Unexpected escaped character ‘{a}’ in regular expression.” : “在正则表达式中出现了没有转义的字符 ‘{a}’”,“Expected ‘{a}’ and instead saw ‘{b}’.” : “应该⽤ ‘{a}’代替’{b}’”,“Spaces are hard to count. Use {{a}}.” : “空格难以统计，请使⽤ {{a}}”,“Insecure ‘{a}’.” : “不安全的 ‘{a}’”,“Empty class.” : “空的class”,“Expected a number and instead saw ‘{a}’.”:“应该⽤数字代替’{a}’”,“‘{a}’ should not be greater than ‘{b}’.”:“‘{a}’不应该⽐’{b}’⼤”,“‘hasOwnProperty’ is a really bad name.”: “‘hasOwnProperty’是关键字”,“‘{a}’ was used before it was defined.”:“‘{a}’未定义就已经使⽤了.”,“‘{a}’ is already defined.”:“‘{a}’被重复定义”,“A dot following a number can be confused with a decimal point.”:“数字后⾯的⼀个点会被误认为是⼗进制的⼩数点”,“Confusing minusses” : “容易混淆的负数表达-”,“Confusing plusses.” : “容易混淆的正数表达+”,“Unmatched ‘{a}’.” : “⽆法匹配的’{a}’”,“Expected ‘{a}’ to match ‘{b}’ from line {c} and instead saw ‘{d}’.”:“在⾏{c}中需要⽤’{a}’和’{b}’匹配，⽤来代替’{d}’”,“Unexpected early end of program.”:“程序不可预期的提前终⽌”,“A leading decimal point can be confused with a dot: ‘.{a}’.”:“‘{a}’前的点容易混淆成⼩数点”,“Use the array literal notation [].”:“使⽤数组的符号 []“,“Expected an operator and instead saw ‘{a}’.”:“需要⽤⼀个符号来代替’{a}’”,“Unexpected space after ‘{a}’.”:“在’{a}’之后不能出现空格”,“Unexpected space before ‘{a}’.”:“在’{a}’之前不能出现空格”,“Bad line breaking before ‘{a}’.”:“在’{a}’之前错误的换⾏”,“Expected ‘{a}’ to have an indentation at {b} instead at {c}.”:“‘{a}’需要在{c}⽽不是{b}处缩进”,“Line breaking error ‘{a}’.”:“换⾏错误 ‘{a}’”,“Unexpected use of ‘{a}’.”:“此处不能⽤’{a}’”,“Bad operand.”:“错误的操作数”,“Use the isNaN function to compare with NaN.”:“使⽤isNaN来与NaN⽐较”,“Confusing use of ‘{a}’.”:“容易混淆的’{a}’的使⽤”,“Read only.”:“只读的属性”,“‘{a}’ is a function.”:“‘{a}’是⼀个函数”,‘Bad assignment.’:“错误的赋值”,“Do not assign to the exception parameter.”:“不要给额外的参数赋值”,“Expected an identifier in an assignment and instead saw a function invocation.”:“在赋值的语句中需要有⼀个标识符，⽽不是⼀个⽅法的调⽤”,“Expected an identifier and instead saw ‘{a}’ (a reserved word).”:“需要有⼀个标识符，⽽不是’{a}’(保留字符)”,“Missing name in function declaration.”:“在⽅法声明中缺少名称”,“Expected an identifier and instead saw ‘{a}’.”:“需要有⼀个标识符，⽽不是’{a}’”,“Inner functions should be listed at the top of the outer function.”:“内部函数的声明应该放在此函数的顶部。