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 offer
LED Lighting 1 An accidental discovery announced recently has taken LED lighting to a new level, suggesting it could soon offer
admin
2009-06-15
41
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 student2 at Vanderbilt University, was just trying to make really small quantum dots, which are crystals generally only a few nanometers big. Quantum dots contain anywhere 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 Bowers’ 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.
选项
答案
B
解析
第一段的第一、第二句是关键。第一句说LED照明经济实惠,经久耐用。第二句说爱迪生的发明将被淘汰。其意思是LED将取代传统照明源,所以,B是答案。
转载请注明原文地址:https://jikaoti.com/ti/naOsFFFM
本试题收录于:
职称英语理工类基础题库职称英语分类
0
职称英语理工类基础
职称英语
相关试题推荐
TheDiscoveryofPenicillin(青霉素)Intheautumnof1928,aScottishscientistAlexanderFlemingwassearchingforasubstance
WhichistrueofmanyAIDSsufferersindevelopingcountries?HowmanypeoplehavediedofAIDSsofar?
WhichistrueofmanyAIDSsufferersindevelopingcountries?AccordingtoLee,ourresponsetotheAIDSdiseaseis
NeedforEmphasisonTreatmentAIDSprogramsindevelopingcountriesputtoolittleemphasisontreatment,theWorldHealthOrga
Thereisanabundantsupplyofcheaplaborinthiscountry.
Accordingtothepassage,whichofthefollowinghaschangedthemostinthelast500years?Whichcountryisthelargestcoffe
EatforaGoodandHealthfulLifeFood(1)usalive.Itisoursustenanceandourpleasure.Butrecently,researchhasshownthat
EatforaGoodandHealthfulLifeFood(1)usalive.Itisoursustenanceandourpleasure.Butrecently,researchhasshownthat
A.NecessityfordevelopingadulteducationB.EarlydaysofadulteducationC.WaysofreceivingadulteducationD.Growthofa
随机试题
影响肺部药物吸收的因素有
简要回答旅游者的心理实质。
A.恶性高血压B.高血压脑病C.高血压性心脏病D.脑梗死E.高血压危象男性,30岁。阵发性头痛,烦躁,心悸,多汗,血压35.2/17.3kPa(265/130mmHg)。最可能的诊断为
关节松动术的禁忌证包括
双层石膏板暗龙骨吊顶,面层与基层板的接缝应(),并()同一根龙骨上。
《文物保护法》规定,不符合在文物保护单位保护范围和建设控制地带内从事建设活动的相关规定的是()
某制药企业2012年初拥有厂房原值3000万元,4月份给该厂房安装了配套通风管线,整体安装价值300万元;拥有办公楼原值2000万元,6月25日协议将该办公楼的1/3租给某培训机构做儿童家教培训中心,月租金5万元,6月30日该培训中心正式人住,自7月1日开
以下关于个人汽车贷款额度的描述,正确的是()。
下列描述错误的是()。
一个认识的完整过程是()。
最新回复
(
0
)