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
76
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
Theprincipallookedatthisverydarkwomanandthisverypalechildandthoughtabouthowgenesweremiraculousandstrange,b
MostpeoplewouldbeimpressedbythehighqualityofmedicineavailabletomostAmericans.Thereisalotofspecialization,a
Seekingtobuildsupportamongblackfamiliesforitseducationreformlaw,theBushadministrationpaidaprominentblackpundi
Elaineisawomanwhollyincontrolofherbodyandheractions,andherhilariousdeterminationtofindherownhappily-ever-af
下面你将听到一段回忆邓小平同志的发言。上个世纪70年代末,我参加了第四次全国文代会,大会上小平同志致辞时获得的长时间的热烈掌声给我留下了极深的印象。这次大会是文艺界经历十年浩劫后的第…次盛会,也是小平同志复出后第一次代表党中央、国务院同广大文艺工
IamverypleasedtobebackattheXiamenInternationalInvestmentFairagain.Thelevelofinterestandattendancerecognizes
斯蒂芬?斯皮尔伯格最初执导电影的时候,导演在好莱坞最为重要,而如今拍摄电影正值市场控制了整个行业。无论在哪个时期他始终是世界上最有分量的制片人,这说明他才华横溢,又极富变通。斯皮尔伯格对现代电影最重要的贡献在于他有着敏锐的视角去发现并吸引广大观众
下面你将听到一段有关大数据带来的机遇与挑战的讲话。
Women’smindsworkdifferentlyfrommen’s.Atleast,thatiswhatmostmenareconvincedof.Psychologistsviewthesubjecteith
ForyearswehavebeentalkingaboutaddictiontotheInternet,andthentothemobilephone.ArecentsurveyinUKfoundthat_
随机试题
关于头痛伴随症状与疾病的关系A、头痛伴剧烈呕吐B、头痛伴癫痫C、头痛伴视力障碍D、头痛伴眩晕E、头痛伴意识障碍椎一基底动脉供血不足
我国的政体是()。
患儿,5岁,体重25kg,在家玩耍时不慎打翻开水瓶,双下肢被开水烫伤后皮肤出现大水疱,皮薄,疼痛明显,水疱破裂后创面为红色。对于该患儿不正确的急救措施是
进度计划收尾阶段设备监理工程师的具体工作内容包括()。
企业支付现金,只能从开户银行提取。
会计人员如果泄露本单位的商业秘密,可能导致的后果将会有()。
在个人商用房贷款的贷后管理和检查环节,要检查的内容包括()。
绿豆:豌豆
在窗体上绘制一个文本框(名称为Text1)和一个命令按钮(名称为Cmd1,标题为Display)。请编写Cmdl的Click事件过程,使得在程序运行后,按Esc键就调用这个事件过程且在文本框中显示VisualBasic,程序运行结果如下图所示。
A、youagreetodosomethingelseinstead.B、youtryyourbesttoignoreitseffects.C、youareawarethatpeopleareusedtooth
最新回复
(
0
)