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
2013-01-25
30
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.
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 UCLA 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 Urbana-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://jikaoti.com/ti/ip0RFFFM
0
考研英语一
相关试题推荐
YouaregoingtoreadatextaboutChina’stradeachievements,followedbyalistofexamples.Choosethebestexamplefromthe
Television—themostpervasiveandpersuasiveofmoderntechnologies,markedbyrapidchangeandgrowth—ismovingintoanewera,
Whatdoesthewriteractuallysayaboutpronouncingforeignlanguages?Whatisitthatteachersaresaidtobeinclinedtoforg
Thephrase"capitalisingon"(Para.1)canbesubstitutedbyITdirectorsfeelcomfortablebecause
Acollegestudentbecomessocompulsiveaboutcleaninghisdormroomthathisgradesbegintoslip.AnexecutivelivinginNewY
ThedateisJanuary18,2008.Youareamemberofthestudentunionofauniversity.Writeamemorandumtotheheadofthestude
ScottMcNealyandJimBarksdaleslammedBillGatesfor______.AccordingtoNickDonatiello,PresidentofOdysseyCommunications
Themeaningsof"science"and"technology"havechangedsignificantlyfromonegenerationtoanother.Moresimilaritiesthandif
Speech,whetheroralorwritten,isausedcommodity.Ifwearetobeheard,wemust(1)_____ourwordsfromthose(2)_____tou
Speech,whetheroralorwritten,isausedcommodity.Ifwearetobeheard,wemust(1)_____ourwordsfromthose(2)_____tou
随机试题
中国改革40多年来之所以能够顺利推进并取得历史性成就,根本原因在于()
不属于第三代移动通信的标准是__________。
真正结缔组织病包括
著作权所包含的下列权利中,受到保护期限制的是()。
银行对工程项目管理的重点是()。
借款人申请经销商汽车贷款,根据规定,经销商的资产负债率不得超过()。
下列不属于代理记账机构及其从业人员义务的是()。
为练习开车、游乐等目的,偷开他人机动车辆,因过失撞死他人的,()。
DuringMcDonald’searlyyearsFrenchfriesweremadefromscratcheveryday.RussetBur-bankpotatoeswere【C1】______,cutintos
某法人机构持有价值1000万美元的股票投资组合,其β系数为1.2,假设S&P500期货指数为870.4,为防范所持股票价格下跌的风险,此法人应该()。
最新回复
(
0
)