首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
外语
LED Lighting 1 An accidental discovery announced recently has taken LED lighting to a new level, suggesting it could soon o
LED Lighting 1 An accidental discovery announced recently has taken LED lighting to a new level, suggesting it could soon o
admin
2011-01-02
67
问题
LED Lighting
1 An accidental discovery announced recently has taken LED lighting to a new level, suggesting it could soon offer a cheaper, longer-lasting alternative to the traditional light bulb. The breakthrough adds to a growing trend that is likely to eventually make Thomas Edison’s bright invention obsolete. LEDs are already used in traffic lights, flashlights, and architectural lighting. They are flexible and operate less expensively than traditional lighting.
2 Michael Bowers, a graduate student at Vanderbilt University, was just trying to make really small quantum dots, which are crystals generally only a few nanometers big. Quantum dots contain any where from 100 to 1,000 electrons. They’re easily excited bundles of energy, and the smaller they are, the more excited they get. Each dot in Bower’s particular batch was exceptionally small, containing only 33 or 34 pairs of atoms.
3 When you shine a light on quantum dots or apply electricity to them, they react by producing their own light, normally a bright, vibrant color. But when Bowers shined a laser on his batch of dots, something unexpected happened. He was surprised when a white glow covered the table. The quantum dots were supposed to emit blue light, but instead they were giving off a beautiful white glow.
4 Then Bowers and another student got the idea to stir the dots into polyurethane and coat a blue LED light bulb with the mix. The lumpy bulb wasn’t pretty, but it produced white light similar to a regular light bulb.
5 LEDs produce twice as much light as a regular 60 watt bulb and burn for over 50,000 hours. The Department of Energy estimates LED lighting could reduce U.S. energy consumption for lighting by 29 percent by 2025. LEDs don’t emit heat, so they’re also more energy efficient. And they’re much harder to break.
6 Quantum dot mixtures could be painted on just about anything and electrically excited to produce a rainbow of colors, including white. The main light source of the future will almost surely not be a bulb. It might be a table, a wall, or even a fork.
A. LED Lighting Is Not Mature
B. LED Lighting Will Replace Traditional Lighting
C. Almost Everything Could Be the Main Light Source in the Future
D. LED Lighting Has Many Advantages
E. Bowers Made an Unexpected Discovery
F. LED Light Bulbs Look Lumpy
Paragraph 6 ______.
选项
答案
C
解析
由于有了量子点混合剂涂料,几乎任何物体都能用于照明。这是本段的中心思想。所以C是正确答案。
转载请注明原文地址:https://kaotiyun.com/show/3jLd777K
本试题收录于:
职称英语理工类A级题库职称英语分类
0
职称英语理工类A级
职称英语
相关试题推荐
AtosendgoodstovariouspartsoftheworldBatanytimeduringtheyearChasgreatlypromotedtradeDisitpossibletopro
StepBackinTimeDoyouknowthatwelivealotlongernowthanthepeoplewhowerebornbeforeus?Onehundredyearsagot
Weshouldcontemplatedtheproblemfromallsides.
FluShotsOrNot?ItsoundedlikeagoodideawhenNewYorkCity’smayor,RudollphGiuliani,advisedNewYorkersrecentlyto
FluShotsOrNot?ItsoundedlikeagoodideawhenNewYorkCity’smayor,RudollphGiuliani,advisedNewYorkersrecentlyto
ASoot’sRoleinChangesintheClimateandtheAtmosphereBObservationsofWarmingintheNorthernHemisphereCExplanation
AWonderfulChipItistiny,onlyaboutaquarterofaninchsquare,andquiteflat.Underamicroscope,itresemblesasty
HowdoyouaccountforyourabsencefromtheclasslastThursday?
Makesurethetableissecurelyanchored.
随机试题
Apieceofwritinggivinginstructionshasmuchincommonwiththeexplanationofaprocess,【36】itisaddressedtoadifferentr
患者,女,58岁。糖尿病史14年,慢性咳喘4~5年。2年前开始活动后喘加重,曾有夜间突然咳喘,呼吸困难,坐位后缓解。就诊当夜咳喘加重。查体:端坐呼吸,中度发绀。心律失常,频发早搏,心率128次/分。两肺散在哮鸣音,两肺底湿啰音。考虑诊断是
在液压系统中是用压力阀来控制和调节液体压力的。这类阀一般是根据作用在阀芯上的液体压力和弹簧力相平衡的原理而进行工作的。常用的压力控制阀有很多,下述()不属此列。
2018年6月12日,甲公司购入某研发中心(不动产)专用于A产品(免税产品)的研发,取得增值税专用发票注明的价款2000万元,增值税税额为200万元,增值税专用发票当月已通过增值税查询平台勾选确认。甲公司按20年直线法计提折旧,预计净残值为零。由于市场需
以下在风险评估程序中运用分析程序的说法中,错误的是()。
对平等主体的财产关系和人身关系,国家不应过多干预,这是社会主义民主在民事法律关系中的体现。()
我国是一个多民族国家,在社会主义时期,处理民族问题的基本原则是()。
我国能够对民族资本主义经济进行和平赎买政策的条件在于
中国新民主主义革命的胜利,结束了帝国主义、封建主义和官僚资本主义在中国的统治,建立了人民民主专政的中华人民共和国。这是中国历史上的伟大转折点,标志着中国社会进入了新的时期。新民主主义革命时期开展土地革命的实质就是
A、Theygrowuptobefunnyandcharming.B、Theyoftenhaveapoorsenseofdirection.C、Theygetlessattentionfromtheirparen
最新回复
(
0
)