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
Researchers at MIT are developing new technology for converting heat into light and then into electricity that could eventually
Researchers at MIT are developing new technology for converting heat into light and then into electricity that could eventually
admin
2018-06-06
59
问题
Researchers at MIT are developing new technology for converting heat into light and then into electricity that could eventually save fuel in vehicles by replacing less-efficient alternators and allowing electrical systems to run without the engine idling. The technology, called thermophotovoltaics, uses gasoline to heat a light-emitting material, in this case tungsten. A photovoltaic cell then converts the light into electricity. The idea has been around since the 1960s, says John Kassakian, MIT electrical engineering and computer science professor. But until now, the light emitters for the photovoltaics produced inefficient and very costly systems. Improvements in the materials used in these latest devices—possible in part because researchers can modify the material structure at the nano-scale—are now making much more efficient systems, Kassakian says.
According to Kassakian, the system could potentially be a more efficient way to power electrical systems in a vehicle than the current alternator-based one, which wastes energy in two stages: the internal combustion engine converts only about 30 percent of the energy in fuel into movement, and then the alternator is only 50 percent efficient in converting the mechanical energy into electricity. He says a small prototype thermophotovoltaics device that could confirm the system’s improved efficiency might be ready in a year.
The researchers modified the surface structure of the light emitter, etching into it nano-sized pits to tune the wavelengths of light emitted to precisely those a photovoltaic cell can convert most efficiently into electricity. They further refined the device with the use of filters that allow the desired wavelengths of light to pass through to the photovoltaic cells, but reflect other wavelengths back to the light emitter. The reflected light carries energy that helps keep the emitter hot, reducing the amount of fuel needed.
In addition to replacing the alternator with a thermophotovoltaic module, says Kassakian, the technology could be part of an air-conditioning system for vehicles that doesn’t require a compressor. Because this would significantly decrease the load on an engine, it could make it possible to turn off the engine when the vehicle stops in traffic and easily restart it. Today’s hybrids use this technique to save gas, but require large batteries to provide electricity for the radio and lights, and to restart the engine, and they have to turn the engine back on when the battery charge runs out. In the new MIT system, these batteries wouldn’t be necessary.
Which of the following statements best summarizes the weakness of current alternator-based systems in terms of energy waste?
选项
A、Inefficient internal combustion.
B、Inefficient conversions of energy.
C、Inefficient alternator energy use.
D、Inefficient mechanical energy use.
答案
B
解析
转载请注明原文地址:https://kaotiyun.com/show/1mSO777K
本试题收录于:
NAETI中级口译笔试题库外语翻译证书(NAETI)分类
0
NAETI中级口译笔试
外语翻译证书(NAETI)
相关试题推荐
Hewasuncomfortablewiththeirlavishpartiesandtheircollector’szealforthemostexpensive,mostostentatiousbrandnames
Consumers______thecompetitiveresultofyourspecialopponentbutnotyourproduct,becauseitishardtoknowyourproduct’sq
AlthoughothernationscontributedtoNorthSeapollution,muchofthecontaminationwastracedbacktoBritain.
Grubbylittlemanhemaybe—heshitsinmypresencewithoutembarrassment—yetinhisthoughtIperceiveheisfastidious.
U.S.jobgrowthwassurprisinglystrongin2018,butdon’texpectthattohappenagainthisyear,witheconomicheadwindsintens
MymotherandOlgahadmetwhileunderwentfertilitytreatmentsatsomesortofexperimentalprograminoneoftheMoscowclinic
A、Junkfood.B、Toolittleexercise.C、Anincreasinglysedentarylifestyle.D、Alltheabove.D开篇第一句就点出了三个原因,分别是“Junkfood”,“too
过去20年内,随着现代技术的迅速发展,与因特网有关的犯罪活动显著上升,我国政府呼吁国际社会携手合作,遏制这一不良势头。
Doctorsalonemustmakethefinaldecisionwhethertowithdrawtreatment,includingartificialfeeding,andallowaterminallyi
Women’smindsworkdifferentlyfrommen’s.Atleast,thatiswhatmostmenareconvincedof.Psychologistsviewthesubjecteith
随机试题
张老师撰写了一篇学术论文,拟投稿于大学学报,发表之前需要根据学报要求完成论文样式排版。根据考生文件夹下“Word素材.docx”完成排版工作,具体要求如下:依据“论文正样1格式.jpg”中的标注提示,设置论文正文前的段落和文字格式。并参考“论文正样1.
我国《反不正当竞争法》规定,附奖促销所附最高奖的绝对额度是人民币。【】
劳力性日射病常见于
暴风客热最早见于:天行赤眼最早见于:
平面系数K是指( )。
基金募集失败,基金管理人应当自募集届满后( )日内返还投资者已缴纳的款项,并加计银行同期存款利息。
下列实验方案中,能达到实验目的的是()。
2007年10月15日至21日,中国共产党第十七次全国代表大会在北京召开。大会的主题是:高举()伟大旗帜,以邓小平理论和“三个代表”重要思想为指导,深入贯彻落实()。继续解放思想,坚持改革开放,推动科学发展,促进社会和谐,为夺取全面建设
(95年)
Whatifarchitectscouldbuildlivingsystemsratherthanstaticbuildings—dynamicstructuresthatmodifytheirinternalande
最新回复
(
0
)