托福閱讀機(jī)經(jīng)背景文化類(lèi)：稀土與氣候變化

1、智課網(wǎng)TOEFL備考資料托福閱讀機(jī)經(jīng)背景文化類(lèi)：稀土與氣候變化 Science and Technology 科技 Rare earths and climate change 稀土與氣候變化 In a hole? 陷入了危機(jī)? Demand for some rare-earth elements could rapidly outstrip supply 某些稀土元素可能很快會(huì)供不應(yīng)求 MANY plans for reducing the world's emissions of carbon dioxide-at least, those plans formulated by

2、 environmentalists who are not of the hair-shirt, back-to-the-caves persuasion-involve peppering the landscape with wind turbines and replacing petrol-guzzling vehicles with electric ones charged up using energy gathered from renewable resources. The hope is that the level of CO2 in the atmosphere c

3、an thus be kept below what is widely agreed to be the upper limit for a tolerable level of global warming, 450 parts per million. 許多全球性減排二氧化碳的計(jì)劃是要建造星羅棋布的風(fēng)力渦輪發(fā)電機(jī)，并以再生能源發(fā)電為電動(dòng)汽車(chē)充電，擯棄狂吞汽油的汽車(chē)。哦，至少那些并不堅(jiān)決主張嚴(yán)酷節(jié)儉、回返穴居社會(huì) 注 的環(huán)保主義者是這樣計(jì)劃的。人們希望，這樣一來(lái)，大氣中CO2的含量可以保持在百萬(wàn)分之450以下。人們普遍認(rèn)為，這就可以讓全球氣候變暖的程度處在可容忍的上限以下。 Wind tu

4、rbines and electric vehicles, however, both rely on dysprosium and neodymium to make the magnets that are essential to their generators and motors. These two elements, part of a group called the rare-earth metals, have unusual configurations of electrons orbiting their nuclei, and thus unusually pow

5、erful magnetic properties. Finding substitutes would be hard. Motors or generators whose magnets were made of other materials would be heavier, less efficient or both. 但風(fēng)力渦輪發(fā)電機(jī)與電動(dòng)汽車(chē)都要靠鏑與釹來(lái)制造對(duì)電機(jī)和發(fā)動(dòng)機(jī)極為關(guān)鍵的磁鐵。在這兩種同屬稀土金屬的元素中，圍繞原子核旋轉(zhuǎn)的電子排列方式很不尋常，因此具有異乎尋常的強(qiáng)大磁性能。很難找到它們的替代品。用其它材料制造磁鐵的發(fā)動(dòng)機(jī)或電機(jī)或者更為沉重，或者效率不高，或二者兼有

6、。 At the moment, that is not too much of a problem. Though a lot of the supply of rare earths comes from China, whose government has recently been restricting exports (a restriction that was the subject of a challenge lodged with the World Trade Organisation by America, Europe and Japan on March 13t

7、h), other known sources, such as the now-abandoned Mountain Pass mine in California, pictured above, could be brought into play reasonably quickly. At current levels of demand any problem caused by the geographical concentration of supply would thus be an irritating blip rather than an existential c

8、risis. 這一問(wèn)題當(dāng)前還不甚突出。盡管大量稀土來(lái)自中國(guó)，而該國(guó)政府最近一直在限制出口(美國(guó)、歐洲與日本已就此于3月13日向世貿(mào)組織(World Trade Organisation)提起訴訟)，但其它已知礦源，比如現(xiàn)在已放棄開(kāi)采的加州帕斯山(Mountain Pass mine in California)(上圖)，可以在較短時(shí)間內(nèi)重新開(kāi)采供貨。按照當(dāng)前的需求水平，供應(yīng)來(lái)源集中于某地的會(huì)引起的任何問(wèn)題都只不過(guò)會(huì)讓人煩惱一時(shí)，不會(huì)造成生存危機(jī)。 But what if the environmentalists' dream came true? Could demand for d

9、ysprosium and neodymium then be met? That was the question Randolph Kirchain, Elisa Alonso and Frank Field, three materials scientists at the Massachusetts Institute of Technology, asked themselves recently. Their answer, just published in Environmental Science and Technology, is that if wind turbin

10、es and electric vehicles are going to fulfil the role environmental planners have assigned them in reducing emissions of carbon dioxide, using current technologies would require an increase in the supply of neodymium and dysprosium of more than 700% and 2,600% respectively during the next 25 years.

11、At the moment, the supply of these metals is increasing by 6% a year. To match the three researchers' projections it would actually have to increase by 8% a year for neodymium and 14% for dysprosium. 但如果環(huán)保主義者的美夢(mèng)成真了呢?到那時(shí)，鏑與釹的需求也會(huì)得到滿(mǎn)足嗎?這就是麻省理工學(xué)院的三位材料科學(xué)家倫道夫?科爾臣、伊利莎?阿隆索和弗蘭克?菲爾德(Randolph Kirchain, El

12、isa Alonso and Frank Field)最近向自己提出的問(wèn)題。他們?cè)谧罱l(fā)表在環(huán)境科學(xué)與技術(shù)(Environmental Science and Technology)的文章中給出的回答是：如果要讓風(fēng)動(dòng)渦輪發(fā)電機(jī)和電動(dòng)汽車(chē)以現(xiàn)有科技完成環(huán)境規(guī)劃者賦予它們的二氧化碳減排使命，在未來(lái)25年間，釹與鏑的供給量將需要分別增加600%和2500% 以上。這兩種金屬現(xiàn)在的年供給量增長(zhǎng)為6%;要達(dá)到三位研究人員預(yù)計(jì)的水平，鏑與釹的年供給量實(shí)際增長(zhǎng)必須分別為14%與8%。 That will be hard, particularly for dysprosium. Incremental im

13、provements to motors and generators might be expected to bring demand down a bit. But barring a breakthrough in magnet technology (the discovery of a room-temperature superconductor, for example) the three researchers' figures suggest that the world's geologists would do well to start scouring the planet for rare-earth ores now. If they do not, the mood of the Chinese government may be the least of the headaches faced by magnet manufacturers. 這會(huì)是很困難的，對(duì)鏑來(lái)說(shuō)尤其如此。發(fā)動(dòng)機(jī)和發(fā)電機(jī)的逐步改進(jìn)可能會(huì)讓需求有所下降。但這三位研究人員的數(shù)字說(shuō)明，除非電磁技術(shù)