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
考研
You are going to read a text about the topic of nuclear fusion, followed by a list of explanations(or examples). Choose the best
You are going to read a text about the topic of nuclear fusion, followed by a list of explanations(or examples). Choose the best
admin
2010-11-27
94
问题
You are going to read a text about the topic of nuclear fusion, followed by a list of explanations(or examples). Choose the best explanation/example from the list for each numbered subheading/generalization. There is one extra explanation/example which you do not need to use.
Scientists say they have achieved small-scale nuclear fusion in a tabletop experiment, using tried and true techniques that are expected to generate far less controversy than past such claims.
This latest experiment relied on a tiny crystal to generate a strong electric field. While the energy created was too small to harness cheap fusion power, the technique could have potential uses in medicine, spacecraft propulsion, the oil drilling industry and homeland security, said Seth Putterman, a physicist at the University of California at Los Angeles.
Putterman and his colleagues at UCLA, Brian Naranjo and Jim Gimzewski, report their results in Thursday’s issue of the journal Nature.
(41) Held up to ridicule
Previous claims of tabletop fusion have been met with skepticism and even derision by physicists.
(42) Sound theoretical basis
Fusion experts said the UCLA experiment will face far less skepticism because it conforms to well-known principles of physics.
(43) Energy in waiting
Fusion power has been touted as the ultimate energy source and a cleaner alternative to fossil fuels like coal and oil. Fossil fuels are expected to run short in about 50 years.
(44) Process of fusion
In the UCL’A experiment, scientists placed a tiny crystal that can generate a strong electric field into a vacuum chamber filled with deuterium gas, a form of hydrogen capable of fusion. Then the researchers activated the crystal by heating it.
(45) Commercial uses
UCLA’s Putterman said future experiments will focus on refining the technique for potential commercial uses, including designing portable neutron generators that could be used for oil well drilling or scanning luggage and cargo at airports.
In the Nature report, Putterman and his colleagues said the crystal-based method could be used in "microthrusters for miniature spacecraft". In such an application, the method would not rely on nuclear fusion for power generation, But rather on ion propulsion, Putterman said.
"As wild as it is, that’s a conservative application", he said.
A. In fusion, light atoms are joined in a high-temperature process that frees large amounts of energy. It is considered environmentally friendly because it produces virtually no air pollution and does not pose the safety and long-term radioactive waste concerns associated with modern nuclear power plants, where heavy uranium atoms are split to create energy in a process known as fission.
B. The resulting electric field created a Beam of charged deuterium atoms that struck a nearby target, which was embedded with yet more deuterium. When some of the deuterium atoms in the beam collided with their counterparts in the target, they fused. The reaction gave off an isotope of helium along with subatomic particles known as neutrons, a characteristic of fusion. The experiment did not, however, produce more energy than the amount put in—an achievement that would be a huge breakthrough.
C. Another technique, known as sonoluminescence, generates heat through the collapse of tiny bubbles in a liquid. Some scientists claim that nuclear fusion occurs during the reaction, but those claims have sparked sharp debate.
D. In a Nature commentary, Michael Saltmarsh of the Oak Ridge National Laboratory said the process was in some ways "remarkably low-tech", drawing upon principles that were first recorded by the Greek philosopher Theophrastus in 314 B.C. "This doesn’t have any controversy in it because they’re using a tried and true method", David Ruzic, professor of nuclear and plasma engineering at the University of Illinois at Urbane-Champaign, told The Associated Press. "There’s no mystery in terms of the physics".
E. In one of the most notable cases, Dr. B. Stanley Pons of the University of Utah and Martin Fleischmann of Southampton University in England shocked the world in 1989 when they announced that they had achieved so-called cold fusion at room temperature. Their work was discredited after repeated attempts to reproduce it failed.
F. The technology also could conceivably give rise to implantable radiation sources, which could target cancer cells while minimizing damage to healthy tissue. "You could bring a tiny crystal into the body, place it next to a tumor, turn on the radiation and blast the tumor", Putterman told MSNBC.com.
选项
答案
F
解析
副标题及段首句都是说核聚变的商业前景,F项则说核聚变可以用于癌细胞、肿瘤的医学应用,这符合副标题的语义要求,为正确答案。
转载请注明原文地址:https://www.kaotiyun.com/show/XTZ4777K
0
考研英语一
相关试题推荐
(Continued)exposuretostresshasbeenlinkedto(worsened)functioningoftheimmunesystem,(leaving)apersonmoreliable(f
Inthefollowingtext,somesentenceshavebeenremoved.ChoosethemostsuitableonefromthelistA—Grefitintoeachofthen
Theword"contained"(Line6,Paragraph1)mostprobablymeans______.Thebesttitleforthetextwouldbe______.
Theword"perks"(Line1,Paragraph1)mostprobablymeans______Itcanbeinferredthatacompanywhichcannotaffordexpensi
Theword"perks"(Line1,Paragraph1)mostprobablymeans______Accordingtothetext,thereturnofperksismostlybecause
Youaregoingtoreadatextaboutrelationsbetweenmachineandhuman,followedbyalistofexamples.Choosethebestexample
Hawaii’snativeminorityrefersto______.Whichofthefollowinggroupsholdsalessradicalattitudeonthematterofsovereig
Theword"interest"inthefirstparagraphmostprobablymeans_____.Itcanbeinferredfromthetextthat_____.
WhatdidthewritersayhappenedtoMichaelFayinSingapore?Theword"cacophonous"(Para.3)mostprobablymeans______.
ThebesttitleforthispassagemaybeWhenthewritersaysthattheLondonBridgeTowerwouldnotstandinManhattan,hemeans
随机试题
A、Toletthemtrainyoungfishermen.B、Tointroducethesporttothem.C、Togivethemachanceofrelaxation.D、Toprovidemore
企业在新产品开发过程中,市场因素产生的风险主要有()
A、氟尿嘧啶B、氟他米特C、甲氨蝶呤D、羟基脲E、博来霉素主要用于转移性前列腺癌的药物
小贝购得一只世界杯指定用球后兴奋不已,一脚踢出,恰好落入邻居老马家门前的水井中,正在井边清洗花瓶的老马受到惊吓,手中花瓶落地摔碎。老马从井中捞出足球后,小贝央求老马归还,老马则要求小贝赔偿花瓶损失。对此,下列哪些选项是正确的?()
从数量上看,企业有一定数额的资产,就必然会有一定数额的()。
假定从某一股市采样的股票为A、B、C、D四种。在某一交易日的收盘价分别为8元、10元、18元和25元,基期价格分别为5元、8元、12元和20元。用简单算术平均法计算的该市场股价指数为()。
《巴塞尔新资本协议》的新增内容包括()。
“斯芬克斯之谜”中的“斯芬克斯”的身躯是()。
关于天文学,下列说法错误的是:
根据《物权法》的规定,对于占有改定交付方式的,物权变动的生效时间为()。
最新回复
(
0
)