雅思阅读模拟真题——Time to cool it雅思阅读模拟真题——Time to cool it.pdfVIP

智 课 网 雅 思 备 考 资 料 雅思阅读模拟真题——Time to cool it 本文来源于北京语言大学雅思培训中心向网友提供的在难度、长度 、题材、题型方面与雅思考试近似的练习。这些练习，均以必威体育精装版的国外 报刊上的文章为素材，按雅思阅读的题型，出题并提供答案及简单注释 。欢迎大家积极使用。     Time to cool it   1 REFRIGERATORS are the epitome of clunky technology: solid, reliable and just a little bit dull. They have not changed much over the past century, but then they have not needed to. They are based on a robust and effective idea--draw heat from the thing you want to cool by evaporating a liquid next to it, and then dump that heat by pumping the vapour elsewhere and condensing it. This method of pumping heat from one place to another served mankind well when refrigerators main jobs were preserving food and, as air conditioners, cooling buildings. Todays high-tech world, however, demands high-tech refrigeration. Heat pumps are no longer up to the job. The search is on for something to replace them.   2 One set of candidates are known as paraelectric materials. These act like batteries when they undergo a temperature change: attach electrodes to them and they generate a current. This effect is used in infra-red cameras. An array of tiny pieces of paraelectric material can sense the heat radiated by, for example, a person, and the pattern of the arrays electrical outputs can then be used to construct an image. But until recently no one had bothered much with the inverse of this process. That inverse exists, however. Apply an appropriate current to a paraelectric material and it will cool down.   3 Someone who is looking at this inverse effect is Alex Mischenko, of Cambridge University. Using commercially available paraelectric film, he and his colleagues have generated temperature drops five times bigger than any previously recorded. That may be enough to change the phenomenon from a laboratory curiosity to something with commercial applications.   4 As to what those applications might be,