Sugar Power for Cell Phones In fuel cells,chemical reactions generate electrical currents.The process usually relies on precious metals,such as platinum.In living cells,enzymes perform a similar job,breaking down sugars to obtain electrons and produce energy. Minteer and Tamara Klotzbach,also of St Louis University,have now developed polymers that wrap around an enzyme and preserve it in a microscopic pocket.We tailor these pockets to provide the ideal microenvironment for the enzyme,Minteer says.The polymers keep the enzyme active for months instead of days. So far,the new fuel cells dont produce much power,but the fact that they work at all is exciting,says Paul Kenis,a chemical engineer at the University of Illinois2 at Urhana-Champaign3.Just getting it to work. Kenis says,is a major accomplishment. 试题 A When enzymes can be commonly found in living ceils. C When the technology of a new type of fuel cell is suitable for mass production. 1. What trouble did Minteer and Klotzhach have in their research? B They had trouble keeping biological cells active. D They had trouble finding mechanism for producing enzymes. A when bags of enzyme are embedded in the new fuel cell. C when the enzyme oxidizes the glucose from a sugary liquid that goes through a pocket. 2. What is exciting about the new fuel cells? B Their limited power generation capacity is a good beginning. D Their limitless power generation capacity is a major accomplishment, A The new fuel cells run on sugar that is easy to find. C The new fuel cells are biologically degradable, 答案与题解: 1. C A和D明显不是正确答案。B不是正确选择,因为只有当这种新的燃料电池被大规模生产时,才有可能实现用甜饮料给手机提供电能。 2. C 该段第二句When glucose from a sugary liquid penetrates a pocket,the enzyme oxidizes it,releasing electrons and proton中的it指代glucose,而不是a sugary liquid,因 此C是正确选择。 3. D 文章的最后一段指出了这种新型燃料电池的优点,即A、B、C所述内容。最后一句说,科学家预计,在不到三年的时间里这种新技术便可在大众的流行产品中使用。所以D是正确选择。
雅思听力新生报到场景常用词汇整理
雅思听力考试调节心理的十六字箴言
活用教学录音带提高雅思听力
雅思听力场景分析及解题技巧
揭秘雅思听力考试的命题规则
雅思听力备考方法:加强语感和词汇的练习
雅思听力提分的最好方法:听抄
雅思听力场景分析:学习生活困难
雅思听力Sentence Completion的解题攻略
雅思听力区分单词大小写的方法
浅谈如何提高雅思听力水平
雅思听力电话场景数字考点分析
雅思听力动物场景常用词汇整理
雅思听力场景笔记:电话号码
全面快速提高雅思听力需从细节着手
熟悉海外生活习惯 提高雅思听力
雅思听力考试的五点注意事项
雅思听力选课场景词汇及例题讲解
雅思听力医疗场景考察点讲解
雅思听力考试需要实力与技巧相结合
常见雅思听力陷阱大盘点
雅思听力图书馆场景例题分析
影响雅思听力的因素:语速与语音
雅思听力水平提高需增强语感
雅思听力场景词汇:交通工具
立体训练有效提高雅思听力水平
雅思听力提分及填空题解题的方法
雅思听力加分法宝:必备地道口语
四种雅思听力题型的突破方法
雅思听力常考英美国家及地名整理
| 不限 |
| 英语教案 |
| 英语课件 |
| 英语试题 |
| 不限 |
| 不限 |
| 上册 |
| 下册 |
| 不限 |