Uranium enrichment determination by high-energy photon interrogation

There is been an escalation of tensions today on the Korean peninsula with the North Korean military and the South Korean military triggering artillery blushes. Last count, we have 2 dead and some 20 injured. We just heard from the Reuters that the UN security Council is likely to gather for an emergency meeting in the next couple of days. With me here is James Bleeds, the FT’s diplomatic editor. James, very simple question, are we seeing a resumption of war on the Korean peninsula?Well, this is certainly the most serious incident that happened for a while because for the first time we are seeing brushes being traded from land. You’ve see skirmishes at sea. Of course, of course earlier this year, the North Korea sank a South Korean ship with a lost of more than 40 lives. But this is a more serious one because it’s at land it also come of course, a day after North Korea effectively revealed that it has an uranium enrichment facility which is significantly speeding up its process to create nuclear weapon. So enormous round of tension is now developing clearly between North and South.What do you think is the reactions that we gonna see from the South Koreans here? Well, the () of things in the past, the North Korea does a major kind of incursion and the South shows restraint. One of the main reasons I think why the South does show restraint is that it knows all out the war fair between the two sides being absolutely catastrophe. From the North Korean point of view, they know, if they know anything, they can’t possibly win a kind conventional war against the South. They have about a million under arms but it’s not a strong army, doesn’t have strong access to things like fuel and supplies. It doesn’t have conventional forces. The South would win easily. The South has 30 thousand US troops. The problem for the South is that any victory against the North would be a completely () victory. So the South Korean capital is only 25 kilometers from the demilitarized zone that separates North and South. So the North would the very least be able to do a massive artilary against the Seoul population. The estimates are that about half a million people would die in all-out war against North and South. So the idea is that there could actually being a all-out war would be pretty much unthinkable..What is the North Korea up to here? What is it caused this?I think there are two things that people think are happening, the first is obviously a succession taking place, from Kim Jiongri to Kim joingwoo, in the North, his son. And what is being done is a kind of show of a strength that happening both on the nuclear side and the on conventional military side to sort of underpin that succession with others people possibly in North Korea not want that to happen. The other thing that the North Korea probably wanting to do is to show the US and China that it is still a big play and still do lots of things that they don’t like. They want to lead towards the resumption of the 6-party talks which were abandoned April last year. What they effectively want is to end sanctions, more economic support but ability to retain parts of their nuclear programs. This is to try to underpin that position.You mentioned China. How does China’s react is to appeal calm today so far. But whether they go from here?China is clearly a big play on this. On the one hand, China is by far and way the North Korea’s closest support that have its historical linked back to the regional Korean war in the 1950s when China supported the North. It also has a big trade relationship. China is very concerned in particular about the North regime is not stabilized. It has a 800 miles ofborers. It doesn’t want to see a huge refugee crisis developing if the North would collapse. So it has been very supportive to the Kim Jiongri regime. Nevertheless, China does not want to see unplanned and difficult escalations of that kind the North is doing. And so it may reaction very badly and toughly what the North is doing.James, just briefly, the US potion, how is US gonna react?The US’s fundamental concern is nuclear proliferation. Up till now, it has been very firm, not wanting to deal with North Korea, not wanting the resumption of the 6-party talks. It wants the fullest possible verification of what the North Korea is doing. But ultimately, the ball is on the China’s court. What China does,the UN as you mentioned at the start, UN Security Council. () response is will be absolutely critical in determining whether this escalates or not.Just quickly on Iran, another so called rogue nuclear state. We get the regular report of the IAEA nuclear inspectors today. What’s that gonna show us?The advance brief report suggests that Iran has had quite a number of difficulties with its nuclear program. And suggestion, this is speculation is that the stuxnet virus which people have been talking about earlier this year a kind of cyber war fair worm may have done some damage. If you like, the contrast you got today is that the North Korea crisis is really developing and lots of concerns about their uranium enrichment plans. Conversely, Iran seems to be having more and more problems developing its nuclear facilities. The question is whether we actually see a () towards even more serious problems for Iran.。

was the one field of awareness about which humans had anything more than the vaguest of insights. It is impossible to know today just what our Stone Age ancestors knew about plants, but from what we can observe of preindustrial societies that still exist, a detailed learning of plants and their properties must be extremely ancient. This is logical. Plants are the basis of the food pyramid for all living things, even for other plants. They have always been enormously important to the welfare of people, not only for food, but also for clothing, weapons, tools, dyes, medicines, shelter, and a great many other purposes. Tribes living today in the jungles of the Amazon recognize literally hundreds of plants and know many properties of each. To them botany, as such, has no name and is probably not even recognized as a special branch of "knowledge" at all. Unfortunately, the more industrialized we become the farther away we move from direct contact with plants, and the less distinct our knowledge of botany grows. Yet everyone comes unconsciously on an amazing amount of botanical knowledge, and few people will fail to recognize a rose, an apple, or an orchid. When our Neolithic（新石器时代）ancestors, living in the middle East about 10,000 yearsago, discovered that certain grasses could be harvested and their seeds planted for richer yields the next season, the first great step in a new association of plants and humans was taken. Grains were discovered and from them flowed the marvel of agriculture: cultivated crops. From then on, humans would increasingly take their living from the controlled production of a few plants, rather than getting a little here and a little there from many varieties that grew wild---and the accumulated knowledge of tens of thousands of years of experience and intimacy with plants in the wild would begin to fade away.-------------------------------------------------------------------------------- 1. Which of the following assumptions about early humans is expressed in the passage? A . They probably had a detailed learning of plants. B . They enjoyed the study of welfare. C . They attached much importance to their property. D . They thought that cultivating crops were not important. 正确答案:They probably had a detailed learning of plants. 题目详解:根据问题中…assu mptions about early humans is expressed‟的提示，从第1 段的第3 句中…a detailed learning of plants and their properties must be extremely ancient‟提供的信息判断，选项中的"Theyprobably had a detailed learning of plants" 符合题意。

1 IntroductionVitamin C occurs in different concentrations in a vari-ety of natural samples. It is added to several pharma-ceutical products as an essential ingredient, a stabilizer for vitamin B complex, and as an antioxidant.Consequent upon its desirable effects, it is widely used in the treatment of certain diseases such as scurvy,common cold, anemia, haemorrhagic disorders, wound healing, and even infertility, to mention some stark cases. It is considered essential for the development and regeneration of muscles, bones, teeth and skin.The increasing use of pharmaceuticals and other natural samples containing vitamin C has meant that the practi-cising chemists should develop analytical procedures for its determination which are simple to operate, rapid,accurate, sensitive and selective. The desire to develop methods with ideal characteristics has resulted a large number of procedures with varying applicability. Many instrument-based analyses including fluorometry 1–4,HPLC 5–10, polarography 11–13and enzymatic 14,15methods are reported in the literature. But due to their inherent limitations, these techniques are not commonly used for routine analyses. However, photometric methods are particularly attractive because of their speed and sim-plicity. Consequently, a large number of such proce-dures have been developed for the determination of ascorbic acid (AA). Though some short reviews 16–18have been reported, a critical assessment of these meth-ods is desirable to examine their salient features and utility. This review is an attempt to assess exclusively the existing spectrophotometric methods for the deter-mination of vitamin C as regards their simplicity, rapid-ity, Beer’s law range, sensitivity, selectivity and applic-ability. It is primarily based on the information collect-ed through the Chemical Abstracts for the period 1970to mid-1997.2 Results and DiscussionSeveral dyes such as 2,6-dichlorophenolindophenol (DCIP), dimethoxydiquinone (DMDQ), ninhydrin, fast red AL salt and 2′,7′-dichlorofluorescein etc . have been used for the determination of vitamin C. Among these dyes, DCIP has been most extensively studied. It is included in the official titrimetric methods as reported in different pharmacopoeias 19–21and it also forms the basis of many colorimetric methods. The blue dye DCIP is reduced to the colorless form on addition of ascorbic acid as shown in Fig.1, but it gives a pink color to the acidic solutions. Using the dye, ascorbic acid present in human urine 22and processed potatoes 23has been determined. The excess dye can be extracted with xylene or butanol.24Many substances which are capable of reducing the dye resulting from the prepara-tion and processing of food samples interfere. Flow dialysis proposed by Gary et al .25and continuous flow systems have been used to monitor the decrease in absorbance of DCIP. Such automated systems appear to be justified only when routine analysis of a largeANALYTICAL SCIENCES OCTOBER 1998, VOL. 14Photometric Methods for the Determination of Vitamin CSatya P. A RYA †, Meenakshi M AHAJAN and Preeti J AINDepartment of Chemistry, Kurukshetra University, Kurukshetra –136119, Haryana State, IndiaThe importance of vitamin C to the human body is widely acknowledged throughout the globe. The deficiency of this vitamin leads to various diseases. In view of its importance, numerous methods including spectrophotometric ones have been developed for its determination in pharmaceuticals, foods and biological samples. A comprehensive review of the available spectophotometric methods for the determination of ascorbic acid is presented.Keywords Vitamin C determination, spectrophotometric method†To whom correspondence should be addressed.Fig.1The reduction of DCIP with ascorbic acid.Ascorbic acidDCIP(Oxidized, Blue-Pink)Dehydroascorbic acid DCIP (Reduced, Colorless)number of samples is needed; otherwise it is tedious to use for a single estimation.Dimethoxydiquinone 26gives a violet-colored product with ascorbic acid in a phosphate buffer (pH 6.6). The reduced “indigoid” quinhydrone form is perhaps responsible for the formation of violet-colored product as shown in Fig. 2. After diluting with dioxane,absorbance of the colored solution which is stable over 24 h only under dark conditions is measured at 510 nm.Heating leads to a decrease in color intensity. Beer’s law holds good up to 80 µg ml –1with a detection limit of 10 µg ml –1. Riboflavin and copper interfere. The interference of iron(II) sulfate responsible for precipita-tion can be removed by centrifugation. Though the method is not sufficiently sensitive (ε=1.62×103), it can still be applied to the analysis of citrus fruits 27after extracting the colored product into chloroform (λmax =530 nm). Lin et al .28and Pandey 29reported pro-cedures based on the reaction of ascorbic acid with fast Red AL salt (1)(zinc chloride salt of diazotized 1-aminoanthraquinone) and tetrachlorobenzoquinone (2).The reaction of (1)proceeds in acid medium but the blue color develops only after the addition of alkali,which exhibits three absorption bands between 500–630 nm. If one uses the latter reagent (2), ascorbic acid is determined at 336 nm (ε=535 cm 2mol –1) via a decrease in absorbance of 7×10–4M tetrachlorobenzo-quinone (chloranil) in 80% acetone –water (v/v) medi-um. With these methods, mixtures of ascorbic acid with thiols like o -mercaptobenzoic acid, mercaptosuc-cinic acid, 3-mercaptopropionic acid can not be resolved.Methylene Blue 30, (3)and ninhydrin 31,32(4)find applications with the determination of ascorbic acid in food products. The colorless form of the dye (3)is extracted into chloroform after its reduction with ascor-bic acid; back oxidation of the dihydro derivative to Methylene Blue has been used for the assay of ascorbic acid (λmax =653 nm). The method is reported to be highly sensitive. The reaction of ascorbic acid with ninhydrin carried out on a boiling water bath using 80% aqueous solution as a medium in 0.01 M NH 4OH is used for its determination in pharmaceuticals (λmax =415 nm), but without added advantages.In the sixties, many methods based on the coupling of ascorbic acid with aniline diazonium salts were report-ed. A purplish or blue colored species is produced by these salts with ascorbic acid in alkaline medium.Diazotized-4-methoxy-2-nitroaniline couples withascorbic acid in oxalic acid medium in the presence of ethanol or isopropanol, giving a purplish color in alka-line solutions. Though Fe(II), Sn(II) and dehydroascor-bic acid (DHAA) do not interfere, the presence of reductones and reductic acid requires formaldehyde condensation. Low contents of vitamin C in the pres-ence of flavanoids and pectic substances are also detected. The reaction of ascorbic acid with 4-nitrobenzene diazonium fluoroborate in acetic acid medium was used for its determination at λmax 415 nm.But the mixture has to be kept for 25 min in the dark,followed by the addition of sodium hydroxide. The sensitivity of a large number of stabilized diazonium salts was evaluated; diazotized 4-nitroaniline-2:5-dimethoxy-aniline was found to give the most intense color reaction.Enzymic 33–35colorimetric determinations of ascorbic acid in commercial vitamin C tablets and in fruits and vegetables were made by measuring the absorbance at 358 nm or 320 nm of the resulting products obtained by oxidation of o -phenylenediamine/1,4-diaminobenzene using ascorbate oxidase or peroxidase in presence of H 2O 2at pH 5.3. Ascorbic acid is determined after oxi-dation with mercuric chloride and condensing the DHAA with 4,5-disubstituted phenylenediamine 36,which gives the quinoxaline derivative used for absorbance measurement. The method involving 4-nitro-1,2-phenylenediamine 37(λmax =375 nm) is very complex and laborious, since it involves many time-consuming steps including purification of the sample with anionic Sephadex column.In the recent past, the determination of oxidized and reduced vitamin C in pharmaceuticals, foods and bio-logical samples has gained importance since AA and DHAA redox couple is an important component of many biological systems. Simultaneous measurement of both AA and DHAA using HPLC has been carried out by various workers 38–45in different laboratories.Rose and Nahrwold 38determined AA and DHAA by monitoring UV absorbance at 254 nm and 210 nm respectively for the analysis of foods, biological sam-ples and pharmaceutical preparations. Graham and Donald 39have carried out the analysis at 254 nm after extracting the food samples with 62.5 mM metaphos-phoric acid using an ion exchange column (Aminex-HPX 87H). Both these forms have also been deter-mined in vegetable samples 40using a UV detector (254nm). Yasui and Hayashi 41made such determinations by converting to compounds having λmax at 300 nm under alkaline conditions. Derivatization of DHAA is accel-erated in the presence of sodium borohydride.Validation of the micromethod for the determination of the oxidized and reduced vitamin C in plasma by HPLC fluorescence method has been reported by Tessier et al .45These methods are useful and a single step HPLC assay of such detections has been helpful in overcoming the burden of derivatization.Ascorbic acid gives colored species with substituted benzene such as m -dinitrobenzene 46in formaldehydeFig.2Reduction reaction of dimethoxydiquinone (DMDQ).‘Indigoid’quinhydroneDMDQand trinitrobenzene47in tartrate buffer when studied for its determination over the concentration ranges 2–50 and 0–125 µg ml–1of ascorbic acid respectively. Methanolic solution of resorcinol48gives a pale yellow color (λmax=425 nm) with ascorbic acid in hydrochloric acid medium, obeying Beer’s law for 80–400 µg ml–1. 4-Chloro-7-nitrobenzofurazane49forms a bluish green colored species with ascorbic acid in presence of 0.2 M sodium hydroxide. The absorbance is measured at 582 nm after diluting the reaction contents with 50% (v/v) aqueous acetone solution. Beer’s law is obeyed in the concentration range 5–20 µg ml–1. The colored prod-uct is stable for 30 min only when kept away from direct sunlight or artificial day light. The method is reported free from the interference of all other vitamins and minerals present in multivitamin preparations and can be applied to the analysis of pharmaceuticals, fresh fruit juices and vegetables.Hashmi et al.50proposed a method based on the reac-tion of 2,3,5-triphenyltetrazolium chloride with ascor-bic acid in alkaline medium. The pink solution is allowed to stand in the dark for 30 min at 25˚C; it obeys Beer’s law over the range 5–25 µg ml–1. Sugars (>15 µg ml–1) except sucrose interfere by forming a similar color to that of the reagent. Riboflavin, cyanocobalamin and folic acid interfere due to their own color. Beutler et al.51,52investigated the use of methylthiazolyltetrazolium salt in presence of ascorbate oxidase enzyme and 3-(4,5-dimethylthiazolyl-2-yl)-2,5-diphenyltetrazolium chloride or bromide in the pres-ence of 5-methylphenazinium methyl sulfate (electron carrier) at pH 3.5 for the determination of ascorbic acid in foods, fruit juices and vegetables juices. These reac-tions involve the formation of formazon (λmax=578 nm). The interference of sulfur dioxide requires treat-ment with formaldehyde, and color interference from dark juices is removed by decolorization with 1% polyvinylpolypyrrolidone before filtration. Sorbitol, alcohol and oxalate interfere with the ascorbic acid oxi-dase. However, the effect of oxalate can be checked by adding a slight excess of Ca(II) ions. Other derivatives such as 2,5-diphenyl-3-thiazolyl tetrazolium chloride53 at pH 12.2, 2-(p-iodophenyl)-3-(p-nitrophenyl)-5-phenyltetrazolium chloride at pH 10.5 (λmax=540 nm) and 2,2′,5,5′-tetra-(4-nitrophenyl)-3,3′-(3,3′-dimethoxy-4,4′-biphenyl)ditetrazolium chloride54have also been employed for the assay of ascorbic acid.The coupling of 2,4-dinitrophenylhydrazine (DNPH) with ketonic groups of DHAA and diketogulonic acid (DKGA) has been the basis of many methods for the determination of total vitamin C contents. Proteins present in the samples are precipitated by adding trichloroacetic acid (TCA) and aliquots of filtrate are shaken with acid–washed charcoal (norit) or activated charcoal55to clarify the solutions and to oxidize AA to DHAA. A reducing medium is produced by adding thiourea prior to DNPH addition, otherwise unspecific coloration is given by oxidants. The osazones (λmax=545 nm) thus formed during the 3 h incubation at 37˚C by the reaction of DNPH and DHAA are dis-solved by adding 85% H2SO4. Vitamin C can be extracted with metaphosphoric acid–stannous chloride solution without charcoal treatment for differential determination of DKGA, DHAA and AA in the same tissue extracts. The interference of sugars can be mini-mized by carrying out incubation at 15˚C and measur-ing the absorbance only after adding sulfuric acid for 75 min.56The use of several acid mixtures has been proposed for replacing the tedious dropwise addition of sulfuric acid. Lack of specificity is found with many of these methods; interfering osazones can be separated by chromatographic methods such as TLC57and HPLC58, but at the cost of making these procedures tedious and cumbersome. The nature of DNPH meth-ods for total vitamin C also makes it amenable to auto-matic flow through analyses.59–61 Phenylhydrazinium chloride62produces a yellow color (λmax=395 nm) when treated with ascorbic acid in0.1 M HCl medium. The reaction contents are kept for1 h in an incubator or water bath at 50±2˚C, thus mak-ing the method time-consuming. Beer’s law is obeyed in the range 25–100 µg of ascorbic acid. No interfer-ence is observed from other vitamins, minerals, glucose, sucrose, excipients and reducing agents. However, the presence of excessive amounts of riboflavin requires the addition of 0.5 g talc, which imparts a yellow color to the solution. 3-Methyl-2-benzothiazolone hydrazone63reacts in the presence of sodium metaperiodate to form a blue colored solution (λmax=630 nm) which helps in the determination of ascorbic acid over the range 6–14 meq ml–1.Wang64suggested the use of potassium iodate for the determination of vitamin C in pharmaceuticals. The absorbance is measured either in the UV region (288 nm) or in the visible region (445 nm). Besides aqueous phase measurements, the yellow precipitate can be extracted into chloroform65(λmax=514 nm). The ICl2–generated in the oxidation of AA by iodate66in acid medium in the presence of Cl–ions has been used to iodinate 2′,7′-dichlorofluorescein dye. The iodinated dye (λmax=525 nm) obeys Beer’s law up to 300 µg (ε=8.81×103). Soft drinks67have been analyzed using the reaction of iodine in an acetic acid medium (λmax= 350 nm). Sirividya and Balasubramanian68reported an indirect procedure based on the oxidation of ascorbic acid by a known excess of iodate in the presence of acid for the analysis of pharmaceuticals and fresh fruit juices. The unreacted iodate is used for hydroxylamine oxidation to generate nitrite, which is then diazotized with sulfanilic acid. The resulting diazonium salt is coupled with N-(1-naphthyl)ethylenediamine dihy-drochloride to form an azo dye (λmax=540 nm). The procedure is a complicated one as it involves many steps.The reaction of hexacyanoferrate(III)69(5)was used for the determination of micro quantities of vitamin C by measuring the decrease in color intensity of the reagent (5)(λmax=420 nm) in McIlvaine buffer (pH 5.2)solutions. Beer’s law is restricted within the range 180–270 µg of AA. A 200-fold amount of glucose, urea,citric acid and tartaric acid; 50-fold excess of creatineand 2-fold excess of creatinine do not interfere, but apositive error is observed even with very small quanti-ties of uric acid. In general, all such reagents thatreduce hexacyanoferrate(III) or oxidize hexacyanofer-rate(II) under experimental conditions interfere.Further the utility of the method is limited to colorlesssolutions. Yet another method involving the oxidationof phthalophenone to phenolphthalein by the reagent(5)in alkaline solution was proposed by Al-Tamrah.70This obeys Beer’s law up to 7 µg ml–1(λmax=553 nm). Sugars are tolerated only in microgram amounts. Therelative standard deviation and detection limit are0.65% and 0.1 µg ml–1respectively.Direct UV spectrophotometry71–73with backgroundcorrection methods such as thermal decomposition, UVlight irradiation, catalytic destruction and alkaline treat-ment has been used for the determination of AA in softdrinks, fruit juices and pharmaceuticals. However, therate of thermal decomposition is found to be very low72and fruit juice samples that are unstable to alkalinetreatment, have fine particles, have a deep coloration orcontain high concentrations of caffeine, saccharin,caramel and tannic acid can not be analyzed. Somemethods based on the Cu(II)-catalyzed oxidation arereported for the assay of pharmaceuticals, fruits andbeverages74–77allowing the determination of AA up to120 µg ml–1at λmax=267 nm. Fe(II) interferes seriously. Only minute amounts of folic acid are tolerated. Thepresence of Al(III), Mg(II) or Zn(II) gives a negativeerror due to their catalytic effect.Some methods involving the coinage metal (Cu, Ag,Au) complexes have been worked out. The reductionof Cu(II) in a biphasic system of isopentyl alcohol andan aqueous solution of pH 4.6 to Cu(I), followed by itscomplexation with cuproine to give a colored complex(λmax=454 nm), was reported by Contreras et al.78for the analysis of foods and vegetables. Fresh fruits andvegetables and dehydrated samples were analyzed afterextracting with 5% HPO3and with a 1:1 mixture of0.5% HPO3and 0.05 M H2SO4respectively. Also thecolored complexes of Cu(I) with 2,2-biquinoline79(λmax=540 nm), rhodanine80(λmax=473 nm) and 2,9-dimethyl-1,10-phenanthroline81–83(λmax=450 nm) have been used to determine ascorbic acid in different sam-ples. However, the method using 2,9-dimethyl-1,10-phenanthroline obeys Beer’s law over the range 2–20µg ml–1, though it requires 1 h waiting time for full color intensity. These methods based on the complex-ation of reduced Cu(I) are rather unselective, since sub-stances such as Fe(II), cysteine, or sodium thiosulfatewhich lead to the reduction of Cu(II) to Cu(I) interfereseriously. The gelatin complexes84,85of Ag(I)(λmax=415 nm; ε=2.2×103) and Au(III) (λmax=540 nm;ε=2.3×103) give colored products on adding AA to their alkaline solutions. The procedure as suggested by Pal et al.84is not interfered with by glycine, alanine, fruc-tose, sucrose, citric acid, tartaric acid or other reducingagents.Analytical applications of Molybdenum Blue formedon reduction of phosphomolybdate complex86, ammoni-um molybdate87–89or molybdic acid90have been report-ed by many workers for the determination of ascorbicacid in pharmaceuticals, fruits and vegetables, pastriesand beverages. Ammonium molybdate–sulfuric acidsystem requires 1 h for complete development of colorwith ascorbic acid.87However, such waiting time canbe decreased to 15 min by the addition of metaphos-phoric acid–acetic acid solution.88The colored speciesobeys Beer’s law over the range 2–32 µg ml–1at 760nm (ε=4.3×104). Serious interferences are observed due to phenolic compounds such as catechins, gallicacid, pyrogallol and gallotannins; thiosulfate ions andthiourea. Recently, P-Sb-Mo heteropoly acid91hasbeen used to produce heteropoly blue (λmax=710 nm) for the assay of ascorbic acid over the range 1–50 µgml–1(ε=3.68×103). The use of folin reagent92and folin phenol93(λmax=760 nm) has also been described for the assay of biological samples after deproteinizing withTCA. Beer’s law is obeyed up to 45 µg ml–1. Thecolor development is not obstructed by bovine serumalbumin, adenine, guanine, thymol and oxyhaemoglo-bin. Folin-ciocalteu94reagent reacts with ascorbic acidto give a blue colored complex (λmax=730 nm) as well. However, the method is time-consuming, as the fullcolor intensity requires 40–50 min. Ammonium meta-vanadate95gives a green color (λmax=680 nm) on heat-ing for 10 min in the presence of ascorbic acid.Though the method has been put to use for the analysisof some samples, it is not sufficiently sensitive.Many spectrophotometric methods based on thereduction of Fe(III) to Fe(II) with ascorbic acid, fol-lowed by the complexation of reduced Fe(II) with dif-ferent reagents, have been reported. Amongst them,α,α′-bipyridyl96–101and 1,10-phenanthroline102–109(o-phen) find extensive use in the development of analyti-cal procedures. Most of these methods are time-con-suming, as full color development is achieved onlyafter waiting for 30–60 min. Micromodification97ofthe procedure applicable to human plasma and animaltissue has been reported without the interference of glu-cose, fructose, sucrose, glutathione and cysteine.Recently, the procedure has been simplified by Aryaand Mahajan99so as to require only 5 min waiting time,instead of 30 or 60 min, with Beer’s law range up to 12µg ml–1(λmax=522 nm). Total ascorbic acid has been determined in blood plasma100after reducing DHAA with dithiothreitol at pH 6.5–8.0, removing the excess of dithiothreitol with N-ethylmaleimide and in urine101 by acidifying with TCA and shaking with activated chorcoal. The reduced Fe(II) forms a water-soluble colored complex with o-phenanthroline (λmax=510–515 nm) at pH 1.5–6.5, with obedience of Beer’s law up to 8 µg ml–1(ε=2.2×104). Background correction104 as achieved by Cu(II)-catalyzed oxidation is necessary for most samples, while the addition of NH4F106as theinhibitor of light reduction of Fe(III)-phen complex is needed in some cases. Selectivity for some of these methods is poor. However, an improvement using orange-red ferroin chelate in aqueous micellar medium formed in the presence of the cationic surfactant cetylpyridinium bromide109has been reported (ε=2.6×104at 510 nm). Ascorbic acid in fruits was determined after extracting the ternary complex of Fe(II) with α,α′-bipyridyl/o-phen and sulfophthalein110 dyes into chloroform (λmax=602 nm).Many other compounds including oximes111–113(6), 2-oximinocyclohexanone thiosemicarbazone114(2-OCHT) (7), 2-(5-bromo-2-pyridylazo)-5-dimethyl-aminophenol115(8)and 2-nitroso-5-(N-propyl-N-sulfo-propylamino)phenol116(9)have been investigated for their use in the analysis of pharmaceuticals and biologi-cal samples for ascorbic acid contents. The earlier reported extraction111of Fe(II)-dimethylglyoxime com-plex into chloroform, which allows the determination of 0.04–0.5 mM ascorbic acid, was modified by Arya et al.112They determined its concentration up to 14 µg ml–1at 514 nm. A proportionate decrease in color intensity of Fe(III)-resacetophenone oxime113complex in sodium acetate–acetic acid buffer (pH 5) with the increasing amounts of ascorbic acid was used for its assay in the range 3.5–17.5 µg (ε=4×103). The method using 2-OCHT determines ascorbic acid up to 12 µg ml–1(ε=1.49×104), but is interfered with by metal ions such as Cu(II), Co(II), Ni(II) and Pd(II), in addition to the interference caused by the oxalic acid, riboflavin, oxidants and reductants. Color-forming reactions of Fe(II) with ferrozine117–119(λmax=562 nm) in acidic solu-tions (pH 3–6), TPTZ120–122(λmax=593, 595 nm), quinaldic acid in presence of pyridine123(λmax=380 nm), picolinic acid in presence of pyridine124(λmax=400 nm) and nitroso-R salt125(λmax=705 nm) have been used for the determination of vitamin C in a variety of samples. The reagents picolinic acid and quinaldic acid, when complexed with iron(II) in the presence of pyridine, resulted in methods used successfully in the analysis of pharmaceuticals, food products and biologi-cal samples. The respective colored complexes getting extracted into chloroform obey Beer’s law in the range 0.4–5.6 µg ml–1and 2.5–25 µg ml–1ascorbic acid without the interference of common ingredients of the samples studied. Though the method using ferrozine117 is not interfered with by sucrose, glucose, mannose, fructose and formaldehyde, yet it suffers interferences from tartaric acid, citric acid, Co(II), Ni(II) and Fe(II). However, reactions of citric acid and tartaric acid can be masked by adding Al(III) or La(III) ions and that of iron(II) by passing the solution through a cation exchanger.Most of the reported methods based on the reducing action of ascorbic acid on metal ions invariably make use of an iron(III)–iron(II) redox system. A few use copper(II)–copper(I), vanadium(V)–vanadium(IV) or molybdenum/tungsten blue formation reactions, as mentioned earlier in the text. Arya et al. have reported a new redox system involving Cr(VI)-diphenyl-carbazide complex126(λmax=540 nm), which obeys Beer’s law up to 3.2 µg ml–1. Common additives of pharmaceutical preparations have no adverse effect on the absorbance of the complex. Another fast and facile method based on the proportionate decrease in absorbance of iron(III)-ferronate complex127(λmax=465 nm) by the addition of ascorbic acid was proposed by the same authors after extracting the complex into TBA/CHCl3solution. Beer’s law is valid up to 10 µg ml–1.3 ConclusionEven after the introduction of other instrument-based procedures, photometric methods continue to be of interest because of the ease in accessibility and their quick applicability to the routine analyses. The molar absorptivity for most of the colored species used in col-orimetric analysis of vitamin C lies over the range 103 to 1041 mol–1cm–1at the wavelength of maximum absorbance. This enables the precise determination of vitamin C in a variety of samples. The presence of cer-tain substances, especially the matrix constituents, may cause serious interferences. However, attempts to over-come such interferences either by using masking agents or making preliminary separations are invariably tried, but sometimes without much success, thus resulting in methods of varying selectivity. It has not been possible to categorize the methods based on the selectivity since the relevant data is found to be missing in the summary part of most methods reported in Chemical Abstracts. But none of the methods is found entirely specific for vitamin C. Despite the reporting of several new photo-metric methods, old procedures still continue to be cited in different pharmacopoeias, indicating either the lack of reliability or of general applicability of these methods of vitamin C determination. Research workers try to justify their work in terms of specific applica-tions, but seldom give an comparative account with other methods regarding analysis of particular type of matrix. Therefore, to incorporate the comparative use of such methods under specific analytical environment requires some patience.The authors wish to thank the Chairman, Department of Chemistry, Kurukshetra University, Kurukshetra, for necessary library facilities and Dr. Meenakshi Mahajan is grateful to CSIR for financial assistance.4 References1.H. Nie and S. Peng, Yingyang Xuebao, 6, 293 (1984).2.X. Shao and Y. Zhang, Guangpuxue Yu Guangpu Fenxi,14, 125 (1994).3.K. Vamos, Elmelz Ip., 43, 16 (1989).4.H. P. Huang, R. X. Cai, Y. M. Du and Y. E. 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Liu, Huaxue Shiji, 16, 282 (1994).18. F. Kober, Prax.Naturwiss.Chem., 37, 27 (1988).19.Indian Pharmacopoeia, Photolitho Press, Faridabad, p. 49,1985.20.Pharmacopoeia of the United States XVIII, pp. 51, 52,Mack Printing Co., Easton PA, 1970.21.British Pharmacopeia, p. 901, H. M. Stationary Office,London, 1988.22.T. Koba, M. Motomura, A. Tsuboi, T. Abekawa and K.Ito,Eisei Kensa, 35, 1565 (1986).23.M. J. Egoville, J. F. Sullivan, M. F. Kozempel and W. J.Jones, Am.Potato J., 65, 91 (1988).24.R. Hernandez and F. Bosch, Ars.Pharm., 15, 39 (1974).25.P. J. Gary, G. M. Owen and D. W. Lashley and P. C. Ford,Clin.Biochem., 7, 131 (1974).26.M. A. Eldawy, A. S. Tawfik and S. R. Elshabouri, Anal.Chem., 47, 461 (1975).27.T. Kamangar, A. B. Fawzi and R. H. Maghssoudi, J.Assoc.Off.Anal.Chem., 60, 528 (1977).28.S. Y. Lin, K. J. Duan and C. L. Tsung, Pharm.Acta.Helv., 69, 39 (1994).29.N. K. Pandey, Anal.Chem., 54, 793 (1982).30. A. M. Frigola Canovas and F. Bosch Serrat, An.Bromatol,40, 79 (1988).31.I. 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Garcia-Cantabella, J.Chromatogr.B.Biomed.Appl., 688, 345 (1997).45. F. Tessier, I. Birlouez-Aragon, G. Jani-Chantal and C.Jean, Vitam.Nutr.Res., 66, 166 (1996).46.S. Z. Qureshi, A. Saeed and T. Hasan, Anal.Lett., 22,1927 (1989).47.V. Nirmalchandar and N. Balasubramanian, Z.GesamteHyg.Ihre.Grenzgeb, 33, 497 (1987).48.R. G. Bhatkar and M. H. Saldonha, East Pharm., 25, 117(1982).49.O. H. Abdelmageed, P. Y. Khashaba, H. F. Askal, G. A.Saleh and I. H. Reffat, Talanta, 42, 573 (1995).50.M. H. Hashmi, A. S. Adil, A. Viegas and A. I. Ajmol,Mikrochim.Acta, 3, 457 (1970).51.H. O. Beutler and G. Beinstingl, Dtsch.Lebensm.Rundsch., 76, 69 (1980).52.H. O. Beutler, G. Beinstingl and G. Michal, Ber.—Int.Fruchtsaft Union Wiss—Tech.Komm, 16, 325 (1980). 53.P. W. Alxandrova and A. Nejtscheva, Mikrochim.Acta,1982 I, 387.54.P. V. Aleksandrova and A. Neicheva, Mikrochim.Acta,1979 II, 337.55.G. Xiao and G. Zhao, Shipin Yu Fajiao Gongye, 5, 35(1987).56.O. Pelletier and R. Brassard, J.Food Sci., 42, 1471(1977).57.Z. Zloch, Mikrochim.Acta, 1975, 213.58.S. Garcia-Castineiras, V. D. Bonnet, R. Figueroa and M.Miranda, J.Liq.Chromatogr., 4, 1619 (1981).59.O. Pelletier and R. Brassard, Adv.Automat.Anal.Technicon Int.Congr., 9, 73 (1973).60.O. Pelletier and R. Brassard, J.Assoc.Off.Anal.Chem.,58, 104 (1975).61.W. A. Behrens and R. Madere, Anal.Biochem., 92, 510(1979).62.N. Wahba, D. A. Yassa and R. S. Labib, Analyst[London], 99, 397 (1974).63.M. N. Reddy, G. K. Mohan, N. R. P. Singh and D. G.Sankar, Indian Drugs, 25, 204 (1988).64.Z. Wang, Yingyand Xuebao, 9, 174 (1987).65.W. Zhang, Zhongguo Yiyuan Yaoxue Zazhi, 12, 409(1992).66.N. Balasubramanian, S. Usha and K. Sirividya, IndianDrugs, 32, 73 (1995).67.Y. Yonemura, Y. Miura and T. Koh, Bunseki Kagaku, 39,567 (1990).68.K. Sirividya and N. Balasubramaninan, Analyst[London],121, 1653 (1996).69.N. Burger and V. Karas-Gasparec, Talanta, 20, 782(1973).70.S. A. Al-Tamrah, Anal.Chim.Acta, 209, 309 (1988).71.S. Baczyk and K. Swizinska, Farm.Pol., 31, 399 (1975).72.Y. S. Fung and S. F. Luk, Analyst[London], 110, 201(1985).73.Y. S. Fung and S. F. Luk, Analyst[London], 110, 1439(1985).74.O. W. Lau, S. F. Luk and K. S. Wong, Analyst[London],112, 1023 (1987).75.J. Yan, Zhongguo Yaoxue Zazhi, 25, 478 (1990).。

·82·IMP&HIRFL Annual Report20152-24Selective Uranium Extraction from Salt Lake Brine byAmidoximated Saccharomyces cerevisiaeBai Jing,Yin Xiaojie and Qin ZhiUranium concentration in salt lake brines is tens even thousands times higher than seawater,which makes salt lake brine being another ideal resource for uranium.However,the content of salt lake brine is very complicate,a large amount of K,Na,Ca,Mg elements coexisting with uranium.Hence,only sorbent with high uranium selectivity can be well used in uranium extraction from salt lake brine.Fig.1(color online)Uranium sorption from salt lake brine by raw biomass and amidoximated S.cerevisiae.To enhance the selectivity of Saccharomyces cere-visiae for uranium,amidoximation of the biomass was performed.–CN groups wasfirstly grafted on the biomass surface by radical induced grafting reaction (PAN-B),followed by converting nitrile(–CN)groups to amidoxime(–C(NH2)NOH)groups through reaction with free hydroxylamine(amidoximation).Amidoxi-mated S.cerevisiae(PAO-B)can be obtained through these two steps.The effect of solution pH,extraction time,initial uranium concentration and ion strength on uranium sorption by amdoximated S.cerevisiae was studied in detail and optimum uranium sorption condi-tion was confirmed.Desorption experiment was alsoperformed and the corresponding results showed that amidoximation did not decrease the uranium sorption capacity of the biomass and the amidoximated S.cerevisiae couldbe used at least three times with little loss of uranium uptake capacity.Trace uranium extraction from real salt lake brine samples were conducted,and75%of uranium in the salt lake brine samples was successful absorbed by amidoximated biomass while hardly any uranium was absorbed by raw biomass(Fig.1).Hence,amidoximation can obviously enhance the uranium selectivity of the biomass and amidoximated S.cerevisiae has the potential to selectively extract traceuranium ions from salt lake brine.2-25Gas-phase Chemistry of Short-lived Re Carbonyl Complexes Part1:Adsorption Enthalpy on Teflon SurfaceWang Yang1,Qin Zhi1,Fan Fangli1,Hiromitsu.Haba2,Yukiko.Komori2and Shinya.Yanou2 (1Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou730070,China;2Nishina Center for Accelerator-Based Science,RIKEN,Wako,Saitama351-0198,Japan) In the collaboration of RI Applications Team from RIKEN(Japan)and the Nuclear Chemistry Group from IMP(China),the short-lived Re carbonyl complexes were synthesized and investigated.As the lighter homologs of superheavy element Bh,Re belongs to period6,group7of the periodic table.Short-lived Re isotopes with half-lives of several minutes were produced in the reactions of nat Gd(23Na7+,xn)172−177Re at Nishina center of RIKEN.The nat Gd2O3target with a thickness of340µg·cm−2was prepared by electro deposition onto a2µm Ti foil. The23Na7+ion beam was extracted from RILAC(RIKEN Linear Accelerator).The beam energy was130.6MeV cot. The Gas-filled Recoil Ion Separator(GARIS)was employed to separate the evaporation residues.A gasfilled recoil chamber was installed at the focal plane of GARIS[1].Then,volatile carbonyls were synthesized with short-lived Re isotopes and CO contained gas mixture.Gas-phase chemistry technique was used to measure the adsorption enthalpies of these carbonyls on Teflon(FEP)surface[2].Fig.1shows the experimental setups.Fig.2shows typicalγ-spectra measured with three different kinds of transport.As a result,Re isotopes and their daughters W isotopes were observed in the charcoal trap when CO gas was added into Ar gas,which could prove that volatile Re carbonyls were synthesized with Re atoms and CO gas.After changing the isothermal temperature from25to–70◦C with10◦a step,breakthrough curves of these carbonyls were measured.Monte Carlo simulation program was used to get their adsorption enthalpies on Teflon surface.172,174176Re carbonyls were listed as representative,see Fig.3.。

Geneva, 24 November 2013Joint Plan of ActionPreambleThe goal for these negotiations is to reach a mutually-agreed long-term comprehensive solution that would ensure Iran's nuclear programme will be exclusively peaceful. Iran reaffirms that under no circumstances will Iran ever seek or develop any nuclear weapons.This comprehensive solution would build on these initial measures and result in a final step for a period to be agreed upon and the resolution of concerns. This comprehensive solution would enable Iran to fully enjoy its right to nuclear energy for peaceful purposes under the relevant articles of the NPT in conformity with its obligations therein. This comprehensive solution would involve a mutually defined enrichment programme with practical limits and transparency measures to ensure the peaceful nature of the programme. This comprehensive solution would constitute an integrated whole where nothing is agreed until everything is agreed. This comprehensive solution would involve a reciprocal, step-by- step process, and would produce the comprehensive lifting of all UN Security Council sanctions, as well as multilateral and national sanctions related to Iran's nuclear programme.There would be additional steps in between the initial measures and the final step, including,among other things, addressing the UN Security Council resolutions, with a view towardbringing to a satisfactory conclusion the UN Security Council's consideration of this matter. TheE3+3 and Iran will be responsible for conclusion and implementation of mutual near-termmeasures and the comprehensive solution in good faith. A Joint Commission of E3/EU+3 and Iranwill be established to monitor the implementation of the near-term measures and address issuesthat may arise, with the IAEA responsible for verification of nuclear-related measures. The Joint Commission will work with the IAEA to facilitate resolution of past and present issues ofconcern.Elements of a first stepThe first step would be time-bound, with a duration of 6 months, and renewable by mutual consent, during which all parties will work to maintain a constructive atmosphere for negotiations in good faith. Iran would undertake the following voluntary measures:•From the existing uranium enriched to 20%, retain half as working stock of 20% oxide for fabrication of fuel for the TRR. Dilute the remaining 20% UF6 to no more than 5%.No reconversion line.•Iran announces that it will not enrich uranium over 5% for the duration of the 6 months.1•Iran announces that it will not make any further advances of its activities at the Natanz Fuel Enrichment Plant1, Fordow2,or the Arak reactor3, designated by the IAEA as IR-40.•Beginning when the line for conversion of UF6 enriched up to 5% to UO2 is ready, Iran has decided to convert to oxide UF6 newly enriched up to 5% during the 6 month period, as provided in the operational schedule of the conversion plant declared to the IAEA.•No new locations for the enrichment.•Iran will continue its safeguarded R&D practices, including its current enrichment R&D practices, which are not designed for accumulation of the enriched uranium.•No reprocessing or construction of a facility capable of reprocessing.•Enhanced monitoring:o Provision of specified information to the IAEA, including information on Iran's plans for nuclear facilities, a description of each building on each nuclear site, adescription of the scale of operations for each location engaged in specifiednuclear activities, information on uranium mines and mills, and information onsource material. This information would be provided within three months of theadoption of these measures.o Submission of an updated DIQ for the reactor at Arak, designated by the IAEA as the IR-40, to the IAEA.o Steps to agree with the IAEA on conclusion of the Safeguards Approach for the reactor at Arak, designated by the IAEA as the IR-40.o Daily IAEA inspector access when inspectors are not present for the purpose of Design Information Verification, Interim Inventory Verification, PhysicalInventory Verification, and unannounced inspections, for the purpose of access tooffline surveillance records, at Fordow and Natanz.o IAEA inspector managed access to:centrifuge assembly workshops4;centrifuge rotor production workshops and storage facilities; and,uranium mines and mills.1 Namely, during the 6 months, Iran will not feed UF6 into the centrifuges installed but not enriching uranium. Not install additional centrifuges. Iran announces that during the first 6 months, it will replace existing centrifuges with centrifuges ofthe same type.2At Fordow, no further enrichment over 5% at 4 cascades now enriching uranium, and not increase enrichment capacity. Not feed UF6 into the other 12 cascades, which would remain in a non-operative state. No interconnections between cascades.Iran announces that during the first 6 months, it will replace existing centrifuges with centrifuges of the same type.3 Iran announces on concerns related to the construction of the reactor at Arak that for 6 months it will not commission the reactor or transfer fuel or heavy water to the reactor site and will not test additional fuel or produce more fuel for the reactoror install remaining components.4 Consistent with its plans, Iran's centrifuge production during the 6 months will be dedicated to replace damaged machines.2In return, the E3/EU+3 would undertake the following voluntary measures:•Pause efforts to further reduce Iran's crude oil sales, enabling Iran's current customers to purchase their current average amounts of crude oil. Enable the repatriation of an agreedamount of revenue held abroad. For such oil sales, suspend the EU and U.S. sanctions onassociated insurance and transportation services.•Suspend U.S. and EU sanctions on:o Iran's petrochemical exports, as well as sanctions on associated services.5o Gold and precious metals, as well as sanctions on associated services.•Suspend U.S. sanctions on Iran's auto industry, as well as sanctions on associated services.•License the supply and installation in Iran of spare parts for safety of flight for Iranian civil aviation and associated services. License safety related inspections and repairs in Iran as well as associated services.6•No new nuclear-related UN Security Council sanctions.•No new EU nuclear-related sanctions.•The U.S. Administration, acting consistent with the respective roles of the President and the Congress, will refrain from imposing new nuclear-related sanctions.•Establish a financial channel to facilitate humanitarian trade for Iran's domestic needs using Iranian oil revenues held abroad. Humanitarian trade would be defined as transactionsinvolving food and agricultural products, medicine, medical devices, and medical expensesincurred abroad. This channel would involve specified foreign banks and non-designatedIranian banks to be defined when establishing the channel.o This channel could also enable:transactions required to pay Iran's UN obligations; and,direct tuition payments to universities and colleges for Iranian studentsstudying abroad, up to an agreed amount for the six month period.•Increase the EU authorisation thresholds for transactions for non-sanctioned trade to an agreed amount.5 "Sanctions on associated services" means any service, such as insurance, transportation, or financial, subject to the underlying U.S. or EU sanctions applicable, insofar as each service is related to the underlying sanction andrequired to facilitate the desired transactions. These services could involve any non-designated Iranian entities.6 Sanctions relief could involve any non-designated Iranian airlines as well as Iran Air.3Elements of the final step of a comprehensive solution*The final step of a comprehensive solution, which the parties aim to conclude negotiating and commence implementing no more than one year after the adoption of this document, would: •Have a specified long-term duration to be agreed upon.•Reflect the rights and obligations of parties to the NPT and IAEA SafeguardsAgreements.•Comprehensively lift UN Security Council, multilateral and national nuclear-related sanctions, including steps on access in areas of trade, technology, finance, and energy, ona schedule to be agreed upon.•Involve a mutually defined enrichment programme with mutually agreed parameters consistent with practical needs, with agreed limits on scope and level of enrichmentactivities, capacity, where it is carried out, and stocks of enriched uranium, for a period tobe agreed upon.•Fully resolve concerns related to the reactor at Arak, designated by the IAEA as the IR-40.No reprocessing or construction of a facility capable of reprocessing.•Fully implement the agreed transparency measures and enhanced monitoring. Ratify and implement the Additional Protocol, consistent with the respective roles of the Presidentand the Majlis (Iranian parliament).•Include international civil nuclear cooperation, including among others, on acquiring modern light water power and research reactors and associated equipment, and the supplyof modern nuclear fuel as well as agreed R&D practices.Following successful implementation of the final step of the comprehensive solution for its full duration, the Iranian nuclear programme will be treated in the same manner as that of any non-nuclear weapon state party to the NPT.* With respect to the final step and any steps in between, the standard principle that "nothing is agreed until everything is agreed" applies.4。

开发核能源弊大于利第一：核能是绿色能源吗？也许你会认为核能不会像煤炭和石油等化石燃料那样产生大气污染，也不会排放温室气体二氧化碳，但是你错了！其实事实完全相反。

用于核电的原料之一是铀，铀浓缩设施需要依靠煤炭提供电力的工厂。

这些工厂向大气排放了大量的的二氧化碳。

此外铀浓缩过程还会排放大量氯氟烃，氯氟烃除了导致臭氧层变得稀薄以外，还是比二氧化碳强度高一万到两万倍的温室气体。

此外由于核能发电热效率较低，比一般化石燃料电厂排放更多废热到环境中，故核能电厂的热污染较严重。

而且，在核发电过程中，每年又要向空气和水中持续排放超过上千万居里的放射性同位素。

尽管核工业坚持说，某些放射性物质从生物角度不会引起严重后果。

但事实远非如此。

First: Nuclear energy is green energy sources?You might think that nuclear energy is not like coal and oil and other fossil fuels that produce air pollution, greenhouse gas emissions of carbon dioxide will not, but you are wrong! Quite the opposite in fact. One of the raw materials for nuclear power is uranium, uranium enrichment facilities need to rely on coal to power plants. These factories are a lot of the atmosphere of carbon dioxide emissions. Besides uranium enrichment process also emit large quantities of chlorofluorocarbons, CFCs cause the ozone layer becomes thinner than in addition to, or higher than the carbon dioxide intensity 10000-2 times of greenhouse gases. Furthermore, since the thermal efficiency of nuclear power generation lower than the average fossil fuel power plants emit more heat to the environment, so the nuclear power plant thermal pollution is more serious. Moreover, in the process of nuclear power, but also to the annual emissions of air and water continue to exceed tens of millions of curies of radioisotopes. Although the nuclear industry insists that some of the radioactive material from a biological point of view does not cause serious consequences. However, far from it.第二：核能是高效能源吗？核工业的真正经济价值从来就没有被认真地分析过，这其中包括铀浓缩的成本，发生核事故后的巨大经济索赔，拆卸到期反应堆成本，现有核反应堆的维护，核原料和废料的运输和将放射性核废料储存25万年的所需费用。

AGENERAL ENGLISH QUALIFYING TESTFOR NON-ENGLISH MAJOR GRADUATE STUDENTS(GETJUN2109)考试注意事项一、 本考试由两份试卷组成：试卷一（Paper One）包括听力理解、词汇、完形填空与阅读理解四部分，共80题，按顺序统一编号；试卷二 (Paper Two) 包括翻译与写作两部分，共3题。

二、 试卷一（题号1-80）为客观评分题（听力Section C 部分除外），答案一律用2B铅笔做在机读答题纸上，在对应题号下所选的字母中间划黑道，如[A][B][C][D]。

三、 试卷二为主观评分题，答案做在ANSWER SHEET II上。

答题前，请仔细阅读试卷二的注意事项。

四、 试卷一、试卷二上均不得作任何记号（听力Section C部分除外），答案一律写在答题纸上，否则无效。

五、 本考试全部时间为150分钟，采用试卷一与试卷二分卷计时的办法。

试卷一考试时间为90分钟，听力理解部分以放完录音带为准，大约25分钟；其余部分共计时65分钟，每部分所占时间均标在试卷上，考生可自行掌握。

试卷二共计时60分钟，每部分所占时间均标在试卷上，考生可自行掌握。

六、 试卷一与试卷二采取分别收卷的办法。

每次终了时间一到，考生一律停笔，等候监考教师收点试卷及答题纸。

全部考试结束后，须待监考教师将全部试卷及答题纸收点无误并宣布本考试结束，方可离开考场。

PAPER ONEPART I LISTENING COMPREHENSION (25 MINUTES, 20 POINTS)Section A (1 point each)Directions: In this section, you will hear nine short conversations between two speakers. At the end of each conversation a question will be askedabout what was said. The conversations and the questions will beread only once. Choose the best answer from the four choices givenby marking the corresponding letter with a single bar across thesquare brackets on your machine-scoring Answer Sheet.1. A. Visit her parents.B. Go to the dentist.C. Meet her professor.D. Have a job interview.2. A. Bob is majoring in history.B. Bob is a little boring.C. He likes Bob very much.D. They should invite Bob to the party.3. A. The flight was delayed.B. She didn’t like the movies.C. She had seen both movies before.D. No movies were shown on her flight.4. A. It’s drier.B. It’s wetter.C. It’s abnormal.D. It’s an average year.5. A. Western.B. Horror.C. Science fiction.D. Action.6. A. Wait for Mike.B. Ask Mike to come.C. Pick Mike up in the morning.D. Stop working for the day.7. A. She doesn’t like playing tennis.B. She was thinking the same as the man.C. She had something else in mind.D. She had suggested the same thing earlier.8. A. Matt wants to be cheered up.B. Matt has lost himself.C. Matt worries little about the game.D. Matt feels a little depressed.9. A. The man is a coward.B. The man is too careful.C. Martha likes chicken very much.D. Martha is not the right person for him.Section B (1 point each)Directions: In this section you will hear two mini-talks. At the end of each talk, there will be some questions. Both the talks and the questions will beread to you only once. After each question, there will be a pause.During the pause, you must choose the best answer from the fourchoices given by marking the corresponding letter with a single baracross the square brackets on your machine-scoring Answer Sheet. Mini-talk One10. A. Mr. Lee always wastes time in class.B. Mr. Lee likes talking about history.C. Mr. Lee always feels bored in class.D. Mr. Lee is a little funny.11. A. Boring.B. Satisfactory.C. Inconsistent.D. Inspiring.12. A. Jim has taken a low end job.B. Jim has got a well-paid job.C. Jim is not hopeless in finding a job.D. Jim is desperate in finding a job.Mini-talk Two13. A. The control of drug trafficking in the United States.B. The anti-drug war about the border between Mexico and U.S.C. The investigation of the death of a retired U.S. general.D. The fight of corruption inside Mexican police.14. A. The criminal groups are growing very rapidly.B. The criminal groups can get more profits now.C. Mexican government has not been serious about the drug trade.D. Mexican government is effective in fighting the drug trade.15. A. 6,000B. 10,000C. 45,000D. 54,000Section C (1 point each)Directions: In this section, you will hear a short lecture. Listen to the recording and complete the notes about the lecture. You will hear the recordingtwice. After the recording, you are asked to write down your answerson the Answer Sheet. You now have 25 seconds to read the notesbelow.(请在录音结束后把16-20题的答案抄写在答题纸上)16. For best results with the least risk, tomatoes should be planted when ________.17. Some larger tomatoes may need at least a meter and a half ________.18. The average air temperature should be about _________ Celsius.19. There was a time when people thought tomatoes ________, which is not true.20. Some fruits may be called "vegetables" because they are used in deliciousfoods instead of ________.PART II VOCABULARY (10 minutes, 10 points)Section A (0.5 point each)Directions: There are ten questions in this section. Each question is a sentence with one word or phrase underlined. Below the sentence are fourwords or phrases marked A, B, C and D. Choose the word or phrasethat is closest in meaning to the underlined one. Mark thecorresponding letter with a single bar across the square brackets onyour machine-scoring Answer Sheet.21. People who work overtime at any job are more likely to sustain awork-related injury than those who work their regular hours.support D.sufferendureA.maintainB.C.22. These instruments are so powerful as to enable them to ascertain many factsof the deepest interest.out D.turnoutout C.wearfindputA.outB.23. Kunz looked set to become a star in his field, but he gave it all up after thesefailures.C.D.builtdeterminedA.fixed B.stereotyped24. In the disciplines underlying our high-tech economy, America is steadily losingits global edge.D.territoryappealC.A. borderB. superiority25. The Chinese economy is less affected, so there is no reason to take a dimview of economic growth.A. pessimisticB. blackC. vagueD. positive26. The spacecraft touched down on schedule and the astronauts were helped outof it.crashedD.A. launchedB. operatedC.landed27. In the tropic rainforest there is a wide range of species peculiar to this area.distinct D.odd C.familiarB.A.specific28. The officer distributed among the youngster all the blankets and provisions,withholding himself only a canteen.A. keeping offB. keeping backC. keeping atD. keeping up29. These graduates are more than obliged to the college for the happy four yearsof college life.A. obligatoryB. reluctantC. indifferentD. grateful30. Regular exercise can keep you energetic and contribute to a productive life inthe long run.A. athleticallyB. successivelyC. ultimatelyD. persistentlySection B (0.5 point each)Directions: There are ten questions in this section. Each question is a sentence with something missing. Below each sentence are four words orphrases marked A, B, C and D. Choose the word or phrase that bestcompletes the sentence. Mark the corresponding letter with a singlebar across the square brackets on your machine-scoring AnswerSheet.31. Observers commented that loss of independence was too high a(n) _______ topay for peace.D.expenditurepriceA.costB.expense C.32.The journalist who had set out to obtain these important facts _______ along time to send them.D.consumedpassedA.spentB.took C.33.Telling your doctor about all the medicines you take may help avoid seriousdrug _______.A.interactionsB. interruptionsC. interventionsD. institutions34.Two dozen New Yorkers stood on the platform at the subway station,_______ briefcases and newspapers.clashing D.clarifyingA.clippingB.clutching C.35.Each _______ effort a baby makes at speech is a sign of intellectualdevelopment.clumsy D.chroniccompact C.A.cordialB.36.Iran has expanded its uranium enrichment activities _______ UN demandsto scrap its nuclear-related programs.A. in defiance ofB. in line withC. in return forD. in relation to37.China moved to _______ its grain production when its grain output had keptdeclining for five consecutive years.A.turn upB. take upC. step upD. make up38.The most interesting thing _______ Americans is that they are brought up tobelieve they are the best at everything.A.withB. inC. fromD. about39.The dean asked the secretary if there were enough people _______ to hold afaculty meeting.onhand D.averageC.onendonpurposeA.onB.40.Visitors to this war museum are _______ to see photos of mass massacre byJapanese soldiers.A. amazedB. startledC. wonderedD. startedPART III CLOZE TEST (10 minutes, 10 points, 1 point each)Directions: There are 10 questions in this part of the test. Read the passage through. Then go back and choose one suitable word or phrasemarked A, B, C, or D for each blank in the passage. Mark thecorresponding letter of the word or phrase you have chosen with asingle bar across the square brackets on your machine-scoringAnswer Sheet.It’s a new world, and we barely seem to have noticed. Places we 41 with inexpensive low-end manufacturing are going high-tech in a big 42 .The spotlight is mainly in China and India, for good 43 . The Chinese economy is surging, 44 by increasingly sophisticated engineering, with products 45 from automobiles to semiconductors. India has nearly as46 an economy, powered by a cheap English-speaking labor force who47 in software and services.Along with these 48 giants, countries like Japan, South Korea and Singapore are also challenging America’s 49 . If present trends continue, 90% of all the world’s scientists and engineers will be living in Asia 50 2010, according to Nobel Prize winner Richard E. Smalley, professor of chemistry and physics at Rice University.communicate D.concernassociate C.A.B.41.dealC.way D.routedimension scale B.42.A.effect D.healthpurpose C.reason B.A.43.fueledextinguishedD.burned C.B.A.44.checkeddiffering C.changing D.B.ranging varying45.A.C.staticdynamic D.drastictragic B.46.A.C.bypassovertake D.excelB.A.47.surpassD.mergingsubmergingA.48.emerging B.diverging C.49. A. manipulation B. presidency C. constitution D. dominanceby D.50.in C.before until B.A.PART IV READING COMPREHENSION (45 minutes, 30 points, 1 point each)Directions: In this part of the test, there are five short passages. Read each passage carefully, and then do the questions that follow. Choose thebest answer from the four choices given and mark the correspondingletter with a single bar across the square brackets on yourmachine-scoring Answer Sheet.Passage OneHeadphones used with MP3 digital music players like the iPod may interfere with heart pacemakers（起搏器）and implantable defibrillators（除颤器）, U.S. researchers said.The MP3 players themselves posed no threat to pacemakers and defibrillators, used to normalize heart rhythm. But strong little magnets inside the headphones can foul up the devices if placed within 1.2 inches of them, the researchers told an American Heart Association meeting in New Orleans.Dr. William Maisel of the Medical Device Safety Institute in Boston led a team that tested eight models of MP3 player headphones, including clip-on and ear-plug types, in 60 defibrillator and pacemaker patients.They placed the headphones on the patients' chests, directly over the devices. The headphones interfered with the heart devices in about a quarter of the patients -- 14 of the 60 -- and interference was twice as likely in those with a defibrillator than with a pacemaker.Another study presented at the meeting showed that cellular phones equipped with wireless technology known as Bluetooth are unlikely to interfere with pacemakers.A pacemaker sends electrical impulses to the heart to speed up or slow heart rhythm. The magnet, however, could make it deliver a signal no matter what the heart rate is, the researchers said.An implantable defibrillator signals the heart to normalize its rhythm if it gets too fast or slow. A magnet could de-activate it, making it ignore an abnormal heart rhythm instead of delivering an electrical shock to normalize it.The devices usually go back to working the right way after the headphones are removed, the researchers said."The main message here is: it's fine for patients to use their headphones normally, meaning they can listen to music and keep the headphones in their ears. But what they should not do is put the headphones near their device," Maisel said in a telephone interview.So that means people with pacemakers or defibrillators should not place the headphones in a shirt pocket or coat pocket near the chest when they are not being used, and should not place them over their chest or have others who are wearing headphones rest their head on the patient's chest, Maisel said.51. How can MP3 digital music players hinder pacemakers and defibrillators?A. MP3 players can interfere with heart pacemakers and defibrillators.B. The magnets inside the headphones can interfere with pacemakers anddefibrillators.C. The loud music beats pose a threat to pacemakers and defibrillators.D. MP3 players are placed too close to pacemakers and defibrillators.52. Dr. William Maisel’s tests showed that ________.A. headphones had interference with the heart devices in every patientB. half of the models of MP3 player headphones had interference with heartdevicesC. headphones had much stronger interference with a defibrillator than witha pacemakerD. headphones had much stronger interference with a pacemaker than witha defibrillator53. Bluetooth is mentioned as an example of cell phones that________.A. have little interference with the heart devicesB. are used in the tests in Dr. William Maisel’s studyC. are equipped with wireless technologyD. will replace the MP3 player headphones54. The magnets inside the headphones can cause problems by ________.A. sending out electrical shock to damage heartsB. sending out signals to make hearts beat too slowC. sending out signals to make hearts beat too fastD. making the heart devices malfunction55. People with pacemakers or defibrillators should ________.A. never use MP3 digital music playersB. not use MP3 headphonesC. not use the headphones near their heartsD. put the headphones in a pocket when they are not being used56. The writer’s purpose in writing this article is to ________.A. report the effects of cell phones on heartsB. warn people not to use modern gadgetsC. compare different headphone productsD. inform people of the safe use of MP3 playersPassage TwoCyber crime is likely to bring about as much destruction as the credit crisis in the coming years if international regulation is not improved, some of the world's top crime experts said. Damage caused by cyber crime is estimated at $100 billion annually, said Kilian Strauss, of the Organization for Security and Cooperation in Europe (OSCE)."These criminals outsmart us ten, or a hundred to one," Strauss told Reuters, adding more Internet experts were needed to investigate and tackle cyber crime.Criminal organizations are exploiting a regulatory vacuum to commit Internet crimes such as computer spying, money-laundering and theft of personal information, and the scope for damage is vast, experts told a European Economic Crime conference in Frankfurt. "We need multilateral understanding, account and oversight to avoid, in the years to come, a cyber crisis equivalent to the current financial crisis," Antonio Maria Costa, Executive Director of the United Nations Office on Drugs and Crime, said.Internet crime is also a threat to national security, they said. Several countries, including the United States, have voiced concern over some hackers’ abilities to electronically spy on them and disrupt computer networks.Calls for greater regulation of the Internet come at a time of regulatory renaissance, with policymakers looking to support the powers of financial sector watchdogs in the wake of the global financial crisis. "Because of the transnational nature of identity-related crime, and especially of cyber-crime, if we do not tackle the crime everywhere we will not solve it anywhere," Costa said.The President of Interpol, Khoo Boon Hui, said increasingly highly technological gangs from Asia, Eastern Europe and Africa were coming up with ever more sophisticated ways of swindling money from vulnerable people. He also said there was a trend of company bosses being bribed by fraudsters claiming to have guilty evidence about their firms.Strauss, who works as Senior Program Officer at the Office of the Coordinator of OSCE Economic and Environmental activities, said Internet crime watchdogs could learn a lot from criminals willing to switch sides.57. The main idea of the passage is that ________.A. cyber crime is as destructive as the credit crisis in the coming yearsB. damage caused by cyber-crime is very serious and will get worseC. to fight cyber crime requires enhanced international regulationD. international organizations should be established to crush cyber-crime58. According to Kilian Strauss, ________.A. cyber criminals are 10 or 100 times smarter than Internet expertsB. Internet experts are 10 or 100 times smarter than cyber criminalsC. as cyber criminals are very smart, more experts are needed to fightagainst themD. the investigation of the cyber crime takes time and money59. Criminal organizations can commit internet crimes because ________.A. there is no effective regulationB. they can exploit the present regulationsC. no country has paid enough attention to themD. the current financial crisis has put the authorities at a loss60. To win the war against cyber crime, ________.A. policymakers should support their governments financiallyB. each country should solve its own problems effectivelyC. United States should play a very important roleD. international cooperation is crucial61. The underlined word swindling (in the 5th paragraph) is closest in meaning to“________”.A. bribingB. cheatingC. corruptingD. robbing62. Straus believes that ________.A. Internet security experts can learn a lot from cyber criminalsB. if cyber criminals will cooperate with the police, they can be helpfulC. Internet crime watchdogs will make cyber criminals shift groundsD. international organizations can solve the problems of cyber crimePassage ThreeIt’s hard to know who to trust these days. When we see people staging protests we think, Wow! These folks are passionate about their cause – otherwise, why would they stand in the rain for hours? But sometimes it’s a show: You and even your Congressman may have been raised to power by manipulative marketers who pay serious money to hire protesters.It’s a mean trick. Let’s say you want to stage a political rally, but you just can’t find enough people for a good turnout. What you need are folks with lots of time on their hands, who can be persuaded to make a fuss over almost anything.Solution: Head down to a homeless shelter and take out cash.No joke – hiring the homeless is catching on. Last October, a Georgia activist pushing a state law to crack down on illegal immigrants paid 14 homeless men $10 each to hold signs and march around. It worked. People thought the rally was genuine – a local radio station even broadcast it live. But listeners had no idea this was just a crowd for hire.Pay for rage works – the homeless get a little income and the lobbying group gets a crowd. The only losers are citizens and the media, who think the whole show is legitimate. After a Phoenix TV station recently noticed rallies featuring the homeless, they asked some of the protesters, who were holding signs about a local labor dispute, what they were upset about. Many had no idea. “All we do is stand out here and hold the signs,” said one.Some bold organizers have been known to “borrow” people’s names. In one case a few years ago, members of Congress were swamped with telegrams about a telecom bill. But some constituents were confused when they got phone calls from their concerned Congressmen – because they’d never written in to begin with. It turned out that thousands of the telegrams were faked by a telecom-industry PR firm. And guess what? No aspect of this campaign appears to have violated Postal Service regulations. That means your name could be used next in support of a corporate cause you’ve never heard of.All of this amounts to a corruption of our democratic system: You can’t trust someone who’s calling you about a political issue, and if you write to your Congressman, he might not trust that you haven’t been manipulated.Maybe the solution starts with unmasking all those protest rallies that are just outrage-for-hire purchased down at the local shelter.63. From the first paragraph it can be learned that ________.A. those protesting in the cold rain are respectableB. most Congressmen were elected by fake votesC. in some cases protesters are hiredD. people staging protests are passionate64. Which of the following statements is true?A. The homeless tend to organize protests and rallies.B. Political rallies are sometimes manipulated by power and money.C. The homeless are to blame for deceiving the public and media.D. Political rallies attended by the homeless are on the decline.65. The passage implies that sometimes ________.A. people were deceived into believing that this was a real and legal rallyB. the hired protesters knew clearly what they were pushing forC. such protests have never attracted any attentionD. organizers paid generously for these protesters66. The underlined sentence in Paragraph 4 “pay for rage works” means that________.A. organizers of such rallies have to pay the participantsB. expressing anger can lead to good solutionsC. the homeless have to be paid moreD. hiring people to show your outrage is effective67. To shape the Congressmen’s opinion, a telecom-industry PR firm ________.A. asked the constituents to send telegrams to the CongressmenB. wrote to local residents for supportC. tried to violate Postal Service regulationsD. sent telegrams to the Congressmen in the names of local constituents68. Protest rallies of this kind might result in ________.A. business deceptionsB. disappearance of political trustC. the increase of the homelessD. the collapse of a political partyPassage FourIt had been a long, brutal day on the sales floor for young Brent. He’d had his share of “ups”—what retail salespeople say when it’s their turn with the next customer—and more than his share of downs. And now he was in danger of being shut out for the day.He hadn’t been shut out in a long time. Even in his early days with the company, he could always sell something to someone. He was a natural.But not on this day. This, of course, exposed him to some good-natured ridicule from his associates, who took not-so-secret delight in seeing the sales genius get his stroke of misfortune.Brent had more at stake here than just professional pride and reputation, however. Brent was a new father. He and his wife, Kay, had decided that she would be a full-time mom, which meant he would financially support the family. When he did well on the sales floor, finances weren’t a problem. But when he struggled to make sales, the whole family struggled.Toward the end of the day, a man came in to buy a suit. This was potentially a good sale, the kind that can turn a bad day into a good one—just like that. Brent worked hard to make the sale. But the man hesitated. Brent knew all too well the look he saw in his eyes—the look of a customer about to walk out the door empty-handed. When it became clear that the man was going to leave to do a little comparison shopping, Brent handed him his business card and invited him to return after he’d had a chance to look around.The man looked at Brent’s card, then took a long look at Brent.“So you’re Brent’s boy,” the man said, referring to the card that identified him as Brent Jr.“Do you know my dad?” Brent asked.“Sure do,” the man said. They chatted for a moment, establishing the link between father and son. Then the man said, “Your dad’s a good man. If you’re anything like him . . . well, tell me again about that suit.”Brent called his father that night, but not to recount the story. “I just wanted to thank you,” he said, “for giving me a name I can be proud of.”69. We can learn from Paragraph 2 that as a salesman Brent was ________.A. creativeB. hard-workingC.D.warm-heartedexperienced70. The underlined words “stroke of misfortune” in Paragraph 3 are closest inmeaning to ________.A. change of fateB. bad luckC. a rare opportunityD. an unexpected reward71. It is known from the passage that ________.A. Brent’s family had to struggle to make ends meetB. Brent’s family had to experience a temporary hard timeC. the family’s future depended on Brent and his wife keeping their jobsD. the family’s well-being was closely related to Brent’s sales performance72. As soon as the man entered the store to buy a suit, ________.A. Brent felt that his chance finally cameB. Brent decided to chat with him for a whileC. Brent gave him his greeting and business cardD. Brent was sure that he couldn’t make the sale73. Brent made a call to his father because he________.A. had had a good day on the sales floorB. had met an old friend of his father’s earlier in the dayC. was proud of his father’s achievementD. was grateful for having a respectable name74. We can learn from the story that ________.A. we should cherish what we haveB. the key to success is to never give upC. it is important to have a good reputationD. our family is the most valuable treasurePassage FiveIf the universality of immersion-style language programs, emergency test prep classes, tired college kids is any indication, cramming (临时抱佛脚) is a wildly popular study strategy. Professors frown upon it yet conspire by squeezing vast topics like “Evolution” or “World history 1914 to present” into the last week of a course. So is cramming effective or not? A new study by UC–San Diego psychologists confirms what you may suspect deep down: The answer is no. Hurried memorization is a hopeless approach for retaining information. But it’s not all bad news. The team offers a precise formula for better study habits, and it doesn’t necessarily need dogged discipline and routine.To arrive at their prescription, the scientists tested the “spacing effect” on long-term memory. In other words, they wanted to know how the time gap between study sessions influences the ability to remember material on test day. They asked 1,354 volunteers to memorize 32 trivial facts, such as “Who invented snow golf?” (Rudyard Kipling) and “What European nation consumes the most spicy Mexican food?” (Norway). Participants reviewed the answers anywhere from several minutes to several months after first learning them, and then were tested up to a year later.The findings? Students perform better when they space their study sessions rather than when they try to cram everything into their heads during one sitting. But for those who must cram, timing is everything. According to the researchers, if you have only one date on which to study, choose a day that’s closer to when you first learned the material than when you take the test—but not too close. For instance, if you have a French lesson on Monday and a quiz the following Monday, you should study on Wednesday for maximum retention. Tuesday is too early and Sunday is too late. If you want to remember something for a year, wait。

新闻常用词汇表accredited journalist n.特派记者advertisement n.广告advance n.预发消息；预写消息affair n.桃色新闻；绯闻anecdote n.趣闻轶事assignment n.采写任务attribution n.消息出处；消息来源back alley news n.小道消息backgrounding n.新闻背景Bad news travels quickly. 坏事传千里banner n.通栏标题beat n.采写范围blank vt.“开天窗”body n.新闻正文boil vt.压缩(篇幅)box n.花边新闻brief n.简讯bulletin n.新闻简报byline n.署名文章caption n.图片说明caricature n.漫画carry vt.刊登cartoon n.漫画censor vt.审查(新闻稿件)，新闻审查chart n.(每周流行音乐等)排行榜clipping n.剪报column n.专栏，栏目columnist n.专栏作家continued story 连载故事，连载小说contributing editor 特约编辑contribution n.(投给报刊的)稿件，投稿contributor n.投稿人copy desk n.新闻编辑部copy editor n.文字编辑correction n.更正(启事)correspondence column 读者来信专栏correspondent n.驻外记者，常驻外埠记者cover vt.采访，采写cover girl n.封面女郎covert coverage 隐性采访，秘密采访crop vt.剪辑(图片)crusade n.宣传攻势cut n.插图 vt.删减(字数)cut line n.插图说明daily n.日报dateline n.新闻电头deadline n.截稿时间dig vt.深入采访，追踪(新闻线索)，“挖”(新闻)digest n.文摘editorial n.社论editorial office 编辑部editor's notes 编者按exclusive n.独家新闻expose n.揭丑新闻，新闻曝光extra n.号外eye-account n.目击记，记者见闻faxed photo 传真照片feature n.特写，专稿feedback n.信息反馈file n.发送消息，发稿filler n.补白First Amendment (美国宪法)第一修正案(内容有关新闻、出版自由等) five "W's" of news 新闻五要素(注：请知道5W含义者联系编辑flag n.报头，报名folo (=follow-up) n.连续报道Fourth Estate 第四等级(新闻界的别称)freedom of the Press 新闻自由free-lancer n.自由撰稿人full position 醒目位置Good news comes on crutches.好事不出门。

UU UUY (1H )δU UU UY (1H )δY (1H )δ裂变产额差异法测量235U 丰度乔亚华1陈海英1张敏1杨毅2刘世龙2吴继宗21（环境保护部核与辐射安全中心北京100082）2（中国原子能科学研究院北京102413）摘要利用裂变产额差异法，从裂变产额质量分布曲线，选取位于双驼峰曲线两翼的裂变产物的产额随可裂变核素的不同有很大变化的核素88Rb、104Tc 和92Sr 作为测量对象，选择平均裂变产额比Y/ Y、Y/ Y88 Rb104 Tc92 Sr104 Tc为监测对象，研究了平均产额比与铀丰度之间的关系曲线，获得了平均产额比Yi/ Yj随丰度H0 变化的关系式Y1/Y2=f(H0 )。

利用两条关系曲线分别对72.2%的模拟样品测量5 次，RSD 均优于2%。

将样品分析结果与无源γ射线法的结果相比较，两种方法在规定的误差范围内结果是一致的。

关键词裂变产额，铀同位素，丰度，差异法中图分类号TL275核燃料元件棒是燃料组件的关键部分，燃料元件中芯块的235U 同位素丰度检查是确保核燃料元件在堆中安全可靠运行非常重要的质量控制环节，目的是避免燃料棒在反应堆运行过程中由于235U 富集是一种非常好的中子质询分析源，以其为激发源有可能建立一种灵敏、快速、直接测定铀同位素丰度的方法和装置[3] ，已经在这方面开展了许多工作[4–6]。

本文在前期研究的基础上，选择Y/ Y、88 Rb104 Tc度位置上的不均匀产生的热点可能引起的燃料棒破Y/ Y为研究对象，通过测定其裂变产额比，利92 Sr104 Tc裂。

目前核燃料元件丰度检测的非破坏性的方法有无源γ射线法和252Cf 中子活化分析两种。

无源式燃料棒235U 丰度检测的特点是方法简便，设备造价低，使用安全，缺点是检测速度低，难以满足大量生产核燃料元件的需要。

最大的问题是测量精确度受到芯块年龄影响，用新鲜芯块制造的燃料棒必须等待四个月以上才能进行丰度测量[1]。

5-6Wrecking the Iranian deal has costs. Iran would be freer to ramp up uranium enrichment, putting it once more in sight of a weapon. The nuclear Non-Proliferation Treaty (NPT), still the best bulwark against the spread of the bomb, would be undermined: other countries in the region, such as Saudi Arabia and Egypt, may well respond by dusting off their plans to become nuclear powers; and America would be abandoning a fix that shores up the NPT. Mr Trump would have to work even harder to convince Mr Kim that he can trust America—especially as Mr Bolton compares North Korea to Libya, whose leader gave up a nuclear programme only to be toppled by the West and butchered a few years later.A second problem is mistrust, heightened since the revival of great-power competition between America and Russia after a post-Soviet lull. That ought to give arms control new urgency; instead it is eroding it. Take New START, which caps the number of strategic warheads deployed by Russia and America at 1,550 each. It will expire in 2021 unless Vladimir Putin and Mr Trump extend it, which looks unlikely. Instead Mr Trump boasts that America’s nuclear arsenal will return to the “top of the pack”, bigger and more powerful than ever before. That repudiates the logic of successive strategic-arms-control agreements with Russia since 1972, which have sought to hold back a nuclear arms race by seeking to define parity.破坏伊朗协议是要付出代价的。

XX年VOA常用英文词汇intangible cultural heritage: 非物质文化遗产hold off:保持距离barrage:接连发问sound-detection gear:声音探测器spam:垃圾邮件hideout: 藏身点snap: 仓促的coup plotter: 政变策划者lip synching: 假唱stem cell: 干细胞play up: 大肆渲染graffiti: 涂鸦fever pitch: 高度兴奋, 狂热overstaff: 人员过多peace saboteur: 和平破坏者comatose:昏迷的crackdown:取缔，制裁down-to-earth:实际的，切实的错误的正确：关于名称含有Time的刊物名及其他专有名称的翻译美国报刊用语社会篇Ballistic Missile Test：弹道导弹试验Ordeal：严肃的考查Kidnapper：拐子、绑匪Atomic Nucleus：原子核Confidence Vote：信任票Denuclearization：非核化Blast：爆炸，冲击波Green Belt Movement：绿带运动Argumentative：爱争辩的Cram：塞满、拥挤Snap Poll：即席调查Premature：过早的，仓促的Paralyzed：瘫痪的Lift An Embargo：解除禁运Barbecuestoppage: 中止；中断abstention: 弃权clinical trial: 临床试验Chrysanthemum Throne：天皇王位VaccinateBlockbusterMascotSleasyCULLOut of whackhot words: field work时事热词：riotRed tape：繁文缛节Cold frontAbduct：诱拐，绑架Preemptive：先发制人的Footage：电影胶片Incumbent：现任者，在职者Military Chief：军事最高统领State Visit：国事访问Permanent Member：常任理事国Relevance：意义，有用性Uranium Enrichment：铀浓缩Power Plant：发电站Evacuate：撤退、疏散Bayard：骑士，勇武专门者launch pad: 发射台Constituency：选区，选民at a discountTabloidAchilles' heelPostmodernCome out （of the closet）ReggaeRap musicPlatonicPunkBlackballCoattailLame duckIndependent counselPreset Orbit：预定轨道Milestone：里程碑，转折点Ballistic Missile：弹道导弹NASA：美国国家宇航局Heart Bbypass Surgery：心脏搭桥手术Wail：大哭Denunciation：声讨、指责Hole up：藏匿Step Down：辞职，下台Benchmark：基准点，衡量标准Beaked Whale: 突吻鲸，喙鲸Procurement: 采购Handset: 手机Stake: 股份Portal: 门户网站Showcase: 展现Sedan: 小轿车Strategic Petroleum Reserve: 战略石油储备Back Tax: 退缴税Semiconductor: 半导体Crude Output: 原油生产Log On: 进入系统Lag Behind: 落在后面Team Up: 合作，协作Audience Rating: 收视率Play Down: 对……不太重视Floor Trader: 场内交易人A Package Of Proposals: 一揽子建议Operating Margin: 营运利润率Hedge-Fund: 对冲基金Shortfall: 不足、差额、赤字Anti-Trust: 反托拉斯Full Swing: 达到活动的高潮Claw Back: 夺回，费劲收回Balance Sheet: 资产负债表Inventory: 货存、库存量Mutual Fund: 共同基金Loan Guarante: 借款保函Class Action: 集体诉讼Antidumping：反倾销Confetti: 五彩纸屑Federal Reserve: 美国联邦储备系统Ink：签署（合同、文件等）HSBC: 汇丰银行Hot Money: 国际套利资本Scooter：速克达、踏板车、单脚滑行车IMF：国际货币基金组织In A Row：一个接一个Net Worth：资本净值APEC：亚太经合组织ABM = anti-ballistic missile 反弹道导弹abortive coup attempt 未遂政变absent trial / absent voting 缺席审判/缺席投票absolute majority 绝对多数abstain from voting 弃权abuse of power for personal gain 以权谋私academia 学术界academic career 学历，学业academician 院士Academy Award 奥斯卡金像奖academy sciences 科学院accredited journalist 特派记者acquit / be acquitted 宣告无罪 / 无罪开释acting president 代总统active capital 流淌资本active substance 放射性物质active trade balance 顺差activist 活跃分子administration party 执政党admit the best examinee 择优录用adverse trade balance 逆差advisory body 顾问团after-sale service 售后服务air crash 飞机失事album 专辑allied powers 同盟国all-out ban 全面禁止all-round title 全能冠军alumnus （复数: alumni）校友amendment 修正案，附加条款amicable relations 友好关系amnesty 特赦anarchy 无政府状态animal year 本命年anti-corruption 反腐败 anti-robbery bell 防盗铃apartheid 种族隔离appropriate authorities 有关当局arch-foe 要紧的劲敌armed intervention 武装干涉arm-twisting 施加压力arson 放火，纵火assembly hall 会议厅assembly line 生产流水线assembly man 议员，装配工assistant secretary （美）助理部长assistant secretary of state （美）助理国务卿attaché 专员，（外交使团的）随员audience rating 收视率audiophile 音乐发烧友authoritative information 官方消息authoritative source 权威人士autonomous region / prefecture自治区 / 州axis power 轴心国bachelor mother 未婚母亲background briefing 吹风会，背景情形介绍会bacteria 细菌bail 保释，保释金ballot 选票，投票bank book 银行存折bank failure 银行倒闭bar code 条形码bargain price 廉价be responsible for one's own profit and loss 自负盈亏be honest in performing one's official duties 廉洁奉公beeper BP机behind-the-scene maneuvering 幕后操纵benefit concert 义演音乐会best supporting actress award 最佳女配角bid up price 哄抬物价big gun 有势力的人，名人big lie 大骗局bistro 夜总会black box 测谎器black market price 黑市价blanket ballot 全面选举blast 爆炸blind alley 死胡同blockade 封锁bloodless coup 不流血政变Blue Berets 蓝盔部队bluff diplomacy 恫吓外交bombard 轰炸，炮击boom （经济）繁荣，兴盛borrower 债方botanical garden 植物园bottle up 抑制bottom out 走出低谷box office returns 票房收入box office smash 卖座率高的演出boycott 联合抵制brain drain 人才流失brain gain 人才引进brain trust 智囊团brawn drain 劳工外流bread-and-butter letter 感谢信bribery 行贿bubble economy 泡沫经济bureaucracy 官僚主义bureaucrat 官倒cabinet lineup 内阁阵容cabinet re-shuffle 内阁改组cable car 缆车cable-stay bridge 斜拉桥cadre 干部cafeteria 自助餐厅calamity 灾难campaign against porns 扫黄运动candidate for exam 考生cargo handling capacity 物资吞吐量carnival 狂欢节casualty 遇难者，伤亡人员catch phrase 口头禅，口号ceasefire 停火ceiling price 最高限价celebrity 知名人士cellular phone 移动，老大大censure vote 不信任投票census 人口普查ceremonial usherette 迎宾小姐chamber concert 室内音乐会charity 慈善组织chartered plane 包机china hand 中国通China's actual conditions 中国国情Chinese descendant in America 美籍华裔cholesterol 胆固醇civil servant 公务员civilian 平民classroom boycott 罢课climbout 经济复苏closing address 闭幕辞cloverleaf intersection 立交桥comfortably-off level 小康水平commuter 乘车内班族complains box 意见箱computernik 电脑迷condo（minium）商品房condolence 慰问，吊唁conducted tour 团体旅行confiscate 没收，充公conscience forum 道德法庭conscript 征兵，入伍conservative party 保守党construction of a clean government 廉政建设convenience food 方便食品corruption reporting center 举报中心countdown 倒计时county magistrate 县长cramming system 填鸭式教学法crash program 应急打算criminal law 刑法crude oil 原油cultural undertakings 文化事业curfew 宵禁curriculum vitae 履历表curtain call 谢幕daily necessities 日用品daily turnover 日成交量dan （围棋的）段deadlock 僵局death toll 死亡人数，死亡率defendant 被告deli（catessen）熟食dictatorship 独裁disaster-hit area 灾区disc jockey DJdissolve 解散division chief 处长，科长doctorial tutor 博士生导师door money 入场费dove 主和派，鸽派duet 二重唱Duma （俄）杜马，俄罗斯议会dux 学习标兵，学习尖子economic sanction 经济制裁economic take-off 经济腾飞El Nino 厄尔尼诺现象electric power 电力eliminate 剔除embargo 禁运en route to 在……途中enlisted man 现役军人epidemic 流行病exclusive interview 独家采访expo（sition）博览会face-to-face talk 会面fairplay trophy 风格奖family planning 打算生育flea market 跳蚤市场flying squad 飞虎队frame-up 诬陷，假案front page 头条front row seat 首席记者full house 满座gear…to the international conventions 把…与国际接轨grass widow / widower 留守女士 / 留守男士guest of honor 贵宾guest team / home team 客队 / 主队hawk 主战派heroin 海洛因highlights and sidelights 要闻与花絮his-and-hers watches 情侣表hit parade 流行歌曲排行榜hit product 拳头产品hit-and-runner 肇事后逃走者Hong Kong compatriot 香港同胞honor guard 仪仗队hostage 人质housing reform 住房改革hypermedia 多媒体ideology 意识形状idle money 闲散资金in another related development 另据报道incumbent mayor 现任市长info-highway 信息高速公路in-service training 在职训练inspector-general 总监interim government 过渡政府invitation meet 邀请赛judo 柔道karate 空手道kiosk 小卖部knock-out system 剔除制knowledge economy 知识经济ksei 棋圣laid-off 下岗leading actor 男主角lease 租约，租期man of mark 名人，要人manuscript 原稿，脚本marriage lines 结婚证书master key 万能钥匙medium 媒体，媒介mercy killing 安乐死moped 助力车Moslem 穆斯林multimedia 多媒体music cafe 音乐茶座national anthem 国歌negative vote 反对票nest egg 私房钱news agency 通讯社news briefing 新闻公布会news conference 记者招待会news flash 短讯，快讯nominee 候选人notions 小商品null and void 无效的off-hour hobby 业余爱好off-the-job training 脱产培训on standby 待命on-the-job training 在职培训on-the-spot broadcasting 现场直播opinion poll 民意测验overpass （人行）天桥overseas student 留学生overture 序曲overwhelming majority 压倒性多数palm phone 老大大parliament 国会passerby 过路人pay-to-the-driver bus 无人售票车peaceful co-existence 和平共处peace-keeping force 维和部队peak viewing time 黄金时刻pedestrian 行人pension insurance 养老保险Pentagon 五角大楼perk 外快PM = prime minister 首相，总理politburo 政治局poor box 济贫箱pope 教皇pose for a group photo 集体合影留念poverty-stricken area 贫困地区power failure 断电，停电premiere 首映，初次公演press briefing 新闻公布会press corps 记者团press spokesman 新闻发言人prize-awarding ceremony 颁奖仪式professional escort "三陪"服务profiteer 投机倒把者protocol 草案，协议puberty 青春期public servant 公务员questionnaire 调查表quick-frozen food 速冻食品quiz game 智力竞赛racial discrimination 种族鄙视rapport 默契reciprocal visits 互访recital 独唱会，独奏会red-carpet welcome 郑重欢迎red-hot news 最新消息red-letter day 大喜之日redundant 下岗人员re-employment 再就业rep = representative 代表rip off 宰客senate 参议院tenure of office 任职期the other man / woman 第三者top news 头条新闻tornado 龙卷风tour de force 代表作township enterprises 乡镇企业township head 乡长traffic tie-up 交通瘫痪truce 停火，休战trustee 董事two-day dayoffs 双休日tycoon 巨富umpire 裁判V.D. = venereal disease 性病vaccine 疫苗vehicle-free promenade 步行街vote down 否决well-off level 小康水平well-to-do level 小康水平Who's Who 名人录working couple 双职工。

富硒矿泉水的计划摘要English Summary.Executive Summary.Project: Selenium-Enriched Mineral Water.Objective:This project aims to establish a production facility for selenium-enriched mineral water, leveraging state-of-the-art technology to enhance the natural selenium content of mineral water sources. The enriched water will cater to the growing demand for selenium as a vital nutrient for human health and well-being.Background:Selenium is an essential trace element that plays crucial roles in various bodily functions, includingantioxidant protection, thyroid hormone metabolism, and immune regulation. Deficiencies in selenium have been linked to numerous health issues, including cardiovascular diseases, thyroid disorders, and cognitive decline.Market Opportunity:The global market for selenium supplements andfortified foods is projected to experience significant growth in the coming years, driven by increasing awareness of the health benefits of selenium. Selenium-enriched mineral water presents a unique opportunity to tap into this growing market, offering a convenient and palatable way for consumers to supplement their selenium intake.Production Process:The production process involves extracting mineral water from carefully selected natural sources known for their low selenium content. The water is then subjected to a proprietary enrichment process using nano-selenium technology, which ensures optimal bioavailability andstability of the selenium in the final product.Quality and Safety:Stringent quality control measures are implemented throughout the production process, from raw material selection to finished product packaging. The enriched mineral water undergoes rigorous testing to ensure compliance with all applicable safety and quality standards.Marketing and Distribution:The enriched mineral water will be marketed under a premium brand, emphasizing its unique health benefits and superior quality. Distribution channels will include supermarkets, pharmacies, and online retailers.Financial Projections:Financial projections indicate strong profitability and return on investment. The project is expected to generate significant revenue streams through the sale of selenium-enriched mineral water and related products.Conclusion:The selenium-enriched mineral water project presents a compelling opportunity to meet the growing demand for selenium as a vital nutrient. By harnessing advanced technology and leveraging a high-quality natural resource, we aim to create a product that aligns with the evolving health and wellness needs of consumers.中文回答：执行摘要。

第 36卷 第6期2023 年12月Vol.36　No.6Dec. 2023投稿网址： 石油化工高等学校学报JOURNAL OF PETROCHEMICAL UNIVERSITIES吸附法提铀及提铀吸附剂的种类和性能强化策略白雪1,2，潘建明2（1. 河南工业大学化学化工学院，河南郑州 450001； 2. 江苏大学化学化工学院，江苏镇江 212013）摘要：　控制化石能源的使用、促进可替代新能源和清洁能源的发展，符合资源开发与环境保护协同发展的主题。

核能作为一种能量密度高的绿色能源，其广泛应用可缓解我国的能源短缺问题。

已探明的海水中铀资源约为陆地铀矿的1 000倍，海水提铀是确保铀资源长期供应及核能可持续发展的潜在方法。

吸附法因吸附效率高、操作简单、成本低和绿色环保等优点成为海水中铀酰离子提取的有效方法之一，但面临诸多挑战，如海水中铀酰离子的浓度极低且以Ca2UO2(CO3)3或[UO2(CO3)3]4-的形式稳定存在、共存离子种类和数量较多等。

因此，制备高性能吸附剂是实现海水提铀的关键。

综述了海水提铀吸附剂的类型及其性能强化策略，以期设计海水提铀吸附剂提供帮助。

关键词：　海水提铀；　吸附法；　吸附剂的种类；　性能强化；　偕胺肟；　纳米纤维基吸附剂中图分类号：TQ028 文献标志码： A doi：10.12422/j.issn.1006‐396X.2023.06.003Uranium Extraction by Adsorption and the Types and PerformanceEnhancement Strategies for AdsorbentsBAI Xue1,2，PAN Jianming2（1. School of Chemistry and Chemical Engineering， Henan University of Technology， Zhengzhou Henan 450001， China；2. School of Chemistry and Chemical Engineering， Jiangsu University， Zhenjiang Jiangsu 212013， China）Abstract:　Controlling the use of fossil fuels and promoting the development of alternative new and clean energy sources is consistent with the theme of synergistic development between resource development and environmental protection. As a green energy source with high energy density, nuclear energy can be widely applied to alleviate the energy shortage in our country. The proven uranium resource content in seawater is more than 1 000 times higher than that in uranium mines. Extracting uranium from seawater is a potential way to ensure the long‐term supply of uranium resource and the sustainable development of nuclear power. Adsorption has emerged as one of the effective methods for extracting uranium from seawater due to its advantages of high adsorption efficiency, simple operation, low cost, and environmentally friendly. However, the adsorption faces a number of challenges when extracting uranium from seawater, such as the extremely low concentrations of uranium in seawater and their stable existence in the form of Ca2UO2(CO3)3or [UO2(CO3)3]4-, as well as a large variety and quantity of coexisting ions. Therefore, the preparation of high‐performance adsorbents to achieve efficient and selective separation and enrichment of uranium in seawater is one of the important research topics in the field of environmental science. In this review, the types of adsorbents for uranium extraction from seawater and the performance enhancement strategies of their properties are briefly introduced, with the aim of helping researchers in this field design promising adsorbents for practical seawater uranium extraction.Keywords:　Uranium extraction from seawater；Adsorption；Types of adsorbents；Performance Enhancement；Amidoximes；Nanofiber based absorbent随着我国“双碳”目标的确立，控制化石能源消耗，促进新能源和清洁能源的发展势在必行[1]。

邓稼先：中国核科学的奠基人**Deng Jiaxian: The Founder of China's NuclearScience**In the annals of Chinese science, one name stands tall above the rest - Deng Jiaxian. A legend in his own lifetime, Deng Jiaxian's story is not just about science, but about courage, perseverance, and the unwavering dedication to a nation's cause.Born in 1924 in Anhui province, Deng Jiaxian's earlylife was marked by poverty and hardship. However, this did not deter him from pursuing his passion for science. His determination and hard work led him to secure a place atthe prestigious Peking University, where he studied physics. After graduating, Deng Jiaxian's career took off whenhe was chosen to join the fledgling nuclear science program in China. This was a time when the country was juststarting to explore the mysteries of atomic energy, and Deng Jiaxian was at the forefront of this revolutionary endeavor.Deng's contribution to China's nuclear program was immense. He led numerous research teams and made breakthroughs in areas such as uranium enrichment and nuclear reactor design. His work was crucial in the development of China's first atomic bomb and nuclear power plant.However, Deng Jiaxian's life was not just about scientific achievements. He was a man of principle and integrity, who believed strongly in the peaceful use of nuclear energy. Despite the political upheavals and personal sacrifices he faced during his career, he never compromised on his beliefs.Deng Jiaxian's legacy is not just in the scientific breakthroughs he made, but in the spirit he embodied. His story is a reminder of the power of perseverance and dedication, and the important role that science can play in nation-building.Today, as China continues to make strides in the field of science and technology, the name of Deng Jiaxian serves as a constant reminder of the country's scientific prowessand the priceless contributions made by its bravescientists.**邓稼先：中国核科学的奠基人**在中国科学的史册上，一个名字鹤立鸡群——邓稼先。

两弹一星科学家写的作文英文回答：As a scientist involved in the development of China's nuclear and space programs, I am proud to have contributedto the "Two Bombs, One Satellite" initiative. Thisinitiative refers to the successful development of atomic and hydrogen bombs, as well as the launch of China's first satellite. It was a significant milestone in China's scientific and technological advancements.The development of atomic and hydrogen bombs was a complex and challenging process. It required extensive research, experimentation, and collaboration amongscientists and engineers. The goal was to develop powerful and reliable weapons that could ensure national securityand deter potential threats.One example of the challenges we faced was the need to obtain sufficient amounts of fissile material for the bombs.This required the establishment of large-scale uranium enrichment facilities and the development of advanced centrifuge technology. It was a time-consuming andresource-intensive process, but we were able to overcome these challenges through our determination and expertise.Another example is the development of the Long March rocket, which was used to launch China's first satellite, Dongfanghong-1, in 1970. This was a significant achievement for China's space program and marked our entry into the space race. It required the integration of various technologies, including propulsion systems, guidance systems, and materials science. The successful launch of Dongfanghong-1 demonstrated China's capabilities in space exploration and laid the foundation for future missions.中文回答：作为参与中国核科学和太空计划的科学家，我为自己为“两弹一星”计划做出的贡献感到自豪。

Uranium Enrichment Nuclear FuelProductionUranium enrichment for nuclear fuel production is a controversial topic that elicits strong emotions and differing perspectives. On one hand, proponents argue that nuclear energy is a clean and efficient source of power that can help reduce greenhouse gas emissions and combat climate change. They believe that uranium enrichment is necessary to produce the fuel needed for nuclear reactors to generate electricity. However, opponents raise concerns about the potential risks associated with uranium enrichment, including the proliferation of nuclear weapons and the possibility of accidents or leaks at enrichment facilities. From an environmental perspective, nuclear energy is often touted as a sustainable alternative to fossil fuels. Proponents argue that nuclear power plants produce low levels of greenhouse gas emissions compared to coal or natural gas plants, making them a key player in the fight against climate change. Uranium enrichment is a crucial step in the process of generating electricity from nuclear reactors, as it increases the concentration of the fissile isotope uranium-235 to levels necessary for sustained nuclear reactions. Without uranium enrichment, nuclear power plants would not be able to function efficiently and provide the clean energy needed to power homes and businesses. However, opponents of uranium enrichment point to the potential risks and dangers associated with the process. One major concern is the possibility of nuclear proliferation, as enriched uranium can be used to create nuclear weapons. Countries with nuclear weapons programs, such as North Korea and Iran, have used uranium enrichment facilities to produce the fuel needed for their weapons. This has raised alarm bells in theinternational community and led to calls for greater oversight and regulation of uranium enrichment activities. In addition to proliferation concerns, opponents of uranium enrichment also worry about the environmental and health risks associated with nuclear energy production. Accidents at nuclear facilities, such as the Chernobyl disaster in 1986 and the Fukushima Daiichi meltdown in 2011, have highlighted the potential dangers of nuclear power. While modern nuclear reactors are designed with safety features to prevent such incidents, the possibility ofaccidents or leaks at uranium enrichment facilities remains a cause for concern. Radioactive contamination from uranium enrichment can have long-lasting effects on the environment and public health, making it a contentious issue for communities living near enrichment facilities. Despite these concerns, proponents of uranium enrichment argue that advancements in technology and safety protocols have made nuclear energy production safer and more efficient than ever before. They point to the role of nuclear power in reducing greenhouse gas emissions and providing a reliable source of electricity for countries around the world. With proper regulation and oversight, they believe that uranium enrichment can be conducted responsibly and sustainably, without posing a significant risk to global security or the environment. In conclusion, the debate over uranium enrichment for nuclear fuel production is complex and multifaceted, with valid arguments on both sides of the issue. While proponents emphasize the benefits of nuclear energy in combating climate change and providing a reliable source of electricity, opponents raise concerns about the potential risks of proliferation and environmental contamination. As the world continues to grapple with the challenges of energy production and climate change, finding a balance between the need for clean, reliable energy and the risks associated with nuclear power will be crucial in shaping the future of energy policy.。

病毒危害例子英文作文英文：The harm caused by viruses is widespread and can have serious consequences. One example of this is the WannaCry ransomware attack that occurred in 2017. This virusinfected computers worldwide, encrypting the files on the computer and demanding payment in exchange for the decryption key. The attack affected hospitals, businesses, and even government agencies, causing chaos and disruptions in daily operations.Another example is the Stuxnet virus, which was designed to target industrial control systems. This virus was responsible for causing significant damage to Iran's nuclear program, as it was able to manipulate the centrifuges used in uranium enrichment. The Stuxnet virus was believed to be a joint effort between the United States and Israel, and it demonstrated the potential for cyber warfare to cause physical harm and destruction.Viruses can also be used for espionage and stealing sensitive information. The Flame virus, discovered in 2012, was a sophisticated spyware that was able to record audio, take screenshots, and steal passwords and other sensitive information. This virus was believed to be created by a nation-state and was used to gather intelligence on Middle Eastern countries.In addition to these examples, there are countless other viruses that can cause harm to individuals and organizations. It is important to take measures to protect against these threats, such as regularly updating software and using antivirus software.中文：病毒造成的危害是广泛的，可能会产生严重的后果。

铀矿作业流程Title: Uranium Mining Operation ProcessUranium mining is a complex and detailed process that involves several stages, from exploration and extraction to processing and waste management.铀矿开采是一个复杂且细致的过程，涉及多个阶段，从勘探和提取到加工和废物管理。

The first stage in the process is exploration, where geologists search for uranium deposits.This involves studying the geology of an area and using various methods to identify the presence of uranium.开采过程的第一个阶段是勘探，地质学家在这个阶段寻找铀矿床。

这涉及研究一个地区的地质学，并使用各种方法来确定铀的存在。

Once a deposit has been identified, the next stage is extraction.This involves removing the uranium from the ground and processing it to extract the uranium ore.一旦确定了矿床，下一个阶段就是提取。

这涉及将铀从地下移除，并加工处理以提取铀矿石。

After the uranium ore has been extracted, it needs to be processed to remove the uranium.This is done using a process called uranium beneficiation, which involves separating the uranium from the other materials in the ore.提取出铀矿石后，还需要加工处理以去除铀。