2016考研英语阅读精选：硫化铁量子点能提高电池性能

　　在考研英语中，阅读分数可谓是占到了总分的半壁江山，正所谓“得阅读者得考研”。对于备考2016考研的同学们，在平时的复习中一定要拓展阅读思路，各类话题都要关注，这样才能在整体上提升考研英语阅读水平!新东方在线考研分享《2016考研英语阅读精选》，一起来学习吧!

　　硫化铁量子点能提高电池性能

　　If you add quantum dots - nanocrystals 10,000 times smaller than the width of a human hair - to a smartphone battery it will charge in 30 seconds, but the effect only lasts for a few recharge cycles. However, a group of researchers at Vanderbilt University report in the Nov. 11 issue of the journal ACS Nano that they have found a way to overcome this problem: Making the quantum dots out of iron pyrite, commonly known as fool's gold, can produce batteries that charge quickly and work for dozens of cycles.

　　The research team headed by Assistant Professor of Mechanical Engineering Cary Pint and led by graduate student Anna Douglas became interested in iron pyrite because it is one of the most abundant materials in the earth's surface. It is produced in raw form as a byproduct of coal production and is so cheap that it is used in lithium batteries that are bought in the store and thrown away after a single use.

　　Despite all their promise, researchers have had trouble getting nanoparticles to improve battery performance.

　　"Researchers have demonstrated that nanoscale materials can significantly improve batteries, but there is a limit," Pint said. "When the particles get very small, generally meaning below 10 nanometers (40 to 50 atoms wide), the nanoparticles begin to chemically react with the electrolytes and so can only charge and discharge a few times. So this size regime is forbidden In commercial lithium-ion batteries."

　　Aided by Douglas' expertise in synthesizing nanoparticles, the team set out to explore this "ultrasmall" regime. They did so by adding millions of iron pyrite quantum dots of different sizes to standard lithium button batteries like those that are used to power watches, automobile key remotes and LED flashlights. They got the most bang for their buck when they added ultrasmall nanocrystals that were about 4.5 nanometers in size. These substantially improved both the batteries' cycling and rate capabilities.

　　The researchers discovered that they got this result because iron pyrite has a unique way of changing form into an iron and a lithium-sulfur (or sodium sulfur) compound to store energy. "This is a different mechanism from how commercial lithium-ion batteries store charge, where lithium inserts into a material during charging and is extracted while discharging - all the while leaving the material that stores the lithium mostly unchanged," Douglas explained.

　　【单词详解】

　　1 pint

　　n.品脱

　　参考例句：

　　I'll have a pint of beer and a packet of crisps, please.我要一品脱啤酒和一袋炸马铃薯片。

　　In the old days you could get a pint of beer for a shilling.从前，花一先令就可以买到一品脱啤酒。

　　2 expertise

　　n.专门知识(或技能等)，专长

　　参考例句：

　　We were amazed at his expertise on the ski slopes.他斜坡滑雪的技能使我们赞叹不已。

　　You really have the technical expertise in a new breakthrough.让你真正在专业技术上有一个全新的突破。

　　3 automobile

　　n.汽车，机动车

　　参考例句：

　　He is repairing the brake lever of an automobile.他正在修理汽车的刹车杆。

　　The automobile slowed down to go around the curves in the road.汽车在路上转弯时放慢了速度。

　　4 buck

　　n.雄鹿，雄兔;v.马离地跳跃

　　参考例句：

　　The boy bent curiously to the skeleton of the buck.这个男孩好奇地弯下身去看鹿的骸骨。

　　The female deer attracts the buck with high-pitched sounds.雌鹿以尖声吸引雄鹿。

　　5 capabilities

　　n.能力( capability的名词复数 );可能;容量;[复数]潜在能力

　　参考例句：

　　He was somewhat pompous and had a high opinion of his own capabilities. 他有点自大，自视甚高。 来自辞典例句

　　Some programmers use tabs to break complex product capabilities into smaller chunks. 一些程序员认为，标签可以将复杂的功能分为每个窗格一组简单的功能。 来自About Face 3交互设计精髓

　　6 sodium

　　n.(化)钠

　　参考例句：

　　Out over the town the sodium lights were lit.在外面，全城的钠光灯都亮了。

　　Common salt is a compound of sodium and chlorine.食盐是钠和氯的复合物。

　　7 mechanism

　　n.机械装置;机构，结构

　　参考例句：

　　The bones and muscles are parts of the mechanism of the body.骨骼和肌肉是人体的组成部件。

　　The mechanism of the machine is very complicated.这台机器的结构是非常复杂的。

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