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
Superconducting Ceramic (陶瓷) An underground revolution begins this winter. With the flip (轻击) of a switch, 30,000 homes in on
Superconducting Ceramic (陶瓷) An underground revolution begins this winter. With the flip (轻击) of a switch, 30,000 homes in on
admin
2009-06-15
47
问题
Superconducting Ceramic (陶瓷)
An underground revolution begins this winter. With the flip (轻击) of a switch, 30,000 homes in one part of Detroit will soon become the first in the country to receive electricity transmitted by ice-cold high-performance cables. Other American cities are expected to follow Detroit’s example in the years ahead, which could conserve enormous amounts of power.
The new electrical cables at the Frisbie power station in Detroit are revolutionary because they are made of superconductors. A superconductor is a material that transmits electricity with little or no resistance. Resistance is the degree to which a substance resists electric current. All common electrical conductors have a certain amount of electrical resistance. They convert at least some of the electrical energy passing through them into waste heat. Superconductors don’t. No one understands how superconductivity works. It just does.
Making superconductors isn’t easy. A superconducting material has to be cooled to an extremely low temperature to lose its resistance. The first superconductors, made more than 50 years ago, had to be cooled to -263 degrees Celsius before they lost their resistance. Newer superconducting materials lose their resistance at -143 degrees Celsius.
The superconductors cable installed at the Frisbie station is made of a ceramic material that contains copper, oxygen, bismuth (铋), strontium (锶), and calcium (钙). A ceramic is a hard, strong compound made from clay or minerals. The superconducting ceramic has been fashioned into a tape that is wrapped lengthwise around a long tube filled with liquid nitrogen. Liquid nitrogen is supercold and lowers the temperature of the ceramic tape to the point where it conveys electricity with zero resistance.
The United States loses an enormous amount of electricity each year to resistance. Because cooled superconductors have no resistance, they waste much less power. Other cities are watching the Frisbie experiment in the hope that they might switch to superconducting cable and conserve power, too.
选项
A、With a flip of switch, electricity can be transmitted.
B、Other American cities can benefit from the high-performance cables.
C、Great amounts of power can be conserved.
D、Detroit will first receive electricity transmitted by the new electrical cables.
答案
C
解析
转载请注明原文地址:https://jikaoti.com/ti/YKJsFFFM
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
FamousAmericanFoodsWhat,besideschildren,connectsmothersaroundtheworldandacrosstheseasoftime?It’schicken
HighStressMayDamageMemoryAccordingtoareportissuedinMay1998,elderlypeoplewhohaveconsistentlyhighbloodleve
HighStressMayDamageMemoryAccordingtoareportissuedinMay1998,elderlypeoplewhohaveconsistentlyhighbloodleve
Once-dailyPillCouldSimplifyHIVTreatmentBristol-MyersSquibbandGileadScienceshavecombinedmanyHIVdrugsintoasi
DNAFingerprintingDNAisthegeneticmaterialfoundwithinthecellnucleiofalllivingthings.Inmammals(哺乳动物)thestrand
ListeningtoBirdsongAmalezebrafinchchirpsawaytohimself.Suddenlyhenoticesafemalebirdnearby.Herealizesheha
TimeintheAnimalWorldRhythmcontrolseverythinginNature.(46)Thesunprovidesabasictimerhythmforalllivingcreatures
ThepassagetellsusthatLondon’sfirstLightRailSystemThetrainsontheDLRarecontrolledby
IntenseanddeadlyheatwavehitseasternUSA.
It’simpolitetocutinwhentwopersonsareholdingaconversation.
随机试题
试述CFR术语与CPT术语的联系与区别。
A、fameB、gameC、damnD、sameC
患者,女性,30岁。右侧前臂伸侧散在分布环状结节,直径5mm~3cm,皮损呈淡红色,表面光滑,质地坚韧,境界清楚,无明显自觉症状。本病的典型组织病理学表现是
胸痹属本虚标实之证,其标实常见为下列哪项除外
下列对我国工资保障制度理解有误的是:()。
A、 B、 C、 D、 B第一列为中心对称图形,第二列为轴对称图形,第三列既是轴对称图形又是中心对称图形,B项符合。
[*]
在创建数据库表结构时,为该表中一些字段建立普通索引,其目的是( )。
Lookatthequestionsforthispart.Youwillhearastoryentitled"ShoppingforBargains".Forquestions24-30,indic
Sincetheearly1970’s,historianshavebeguntodevoteseriousattentiontotheworkingclassintheUnitedStates.Yetwhile
最新回复
(
0
)