2015考研英语阅读稀土与气候变化_大学英语阅读

2015考研英语阅读稀土与气候变化

　　但风力涡轮发电机与电动汽车都要靠镝与钕来制造对电机和发动机极为关键的磁铁。在这两种同属稀土金属的元素中，围绕原子核旋转的电子排列方式很不寻常，因此具有异乎寻常的强大磁性能。很难找到它们的替代品。用其它材料制造磁铁的发动机或电机或者更为沉重，或者效率不高，或二者兼有。

　　At the moment, that is not too much of a problem. Though a lot of the supply of rare earthscomes from China, whose government has recently been restricting exports , other known sources, such as the now-abandonedMountain Pass mine in California, pictured above, could be brought into play reasonablyquickly. At current levels of demand any problem caused by the geographicalconcentration of supply would thus be an irritating blip rather than an existential crisis.

　　这一问题当前还不甚突出。尽管大量稀土来自中国，而该国政府最近一直在限制出口提起诉讼)，但其它已知矿源，比如现在已放弃开采的加州帕斯山，可以在较短时间内重新开采供货。按照当前的需求水平，供应来源集中于某地的会引起的任何问题都只不过会让人烦恼一时，不会造成生存危机。

　　But what if the environmentalists dream came true? Could demand for dysprosium andneodymium then be met? That was the question Randolph Kirchain, Elisa Alonso and FrankField, three materials scientists at the Massachusetts Institute of Technology, askedthemselves recently. Their answer, just published in Environmental Science and Technology,is that if wind turbines and electric vehicles are going to fulfil the role environmental plannershave assigned them in reducing emissions of carbon dioxide, using current technologieswould require an increase in the supply of neodymium and dysprosium of more than 700%and 2,600% respectively during the next 25 years. At the moment, the supply of thesemetals is increasing by 6% a year. To match the three researchers projections it wouldactually have to increase by 8% a year for neodymium and 14% for dysprosium.