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
Few human records survive for long, the 16 000-year-old Paleolithic cave paintings at Lascaux, France, being one exception. Now
Few human records survive for long, the 16 000-year-old Paleolithic cave paintings at Lascaux, France, being one exception. Now
admin
2012-07-05
35
问题
Few human records survive for long, the 16 000-year-old Paleolithic cave paintings at Lascaux, France, being one exception. Now researchers led by Alex Zettl of the University of California, have devised a method that will, they reckon, let people store information electronically for a billion years.
Dr. Zettl and his colleagues constructed their memory cell by taking a particle of iron just a few billionths of a meter or nanometers (纳米) across and placing it inside a hollow carbon nanotube. They attached electrodes (电极) to either end of the tube. By applying a current, they were able to shuttle the particle back and forth. This provides a mechanism to create the "1" and "0" required for digital representation: if the particle is at one end it counts as a "1", and at the other end it is a "0".
The next challenge was to read this electronic information. The researchers found that when electrons flowed through the tube, they scattered when they came close to the particle. The particle’s position thus altered the nanotube’s electrical resistance on a local scale. Although they were unable to discover exactly how this happens, they were able to use the effect to read the stored information.
What makes the technique so durable is that the particle’s repeated movement does not damage the walls of the tube. That is not only because the lining of the tube is so hard; it is also because friction is almost negligible when working at such small scales.
Theoretical studies suggest that the system should retain information for a long time. To switch spontaneously from a "1" to a "0" would entail (使必要) the particle moving some 200 nanometers along the tube using thermal energy. At room temperature, the odds (几率) of that happening are once in a billion years. In tests, the stored digital information was found to be remarkably stable. Yet the distance between the ends of the tube remains small enough to allow for speedy reading and writing of the memory cell when it is in use. The next challenge will be to create an electronic memory that has millions of cells instead of just one. But if Dr. Zettl succeeds in commercializing this technology, digital decay itself could become a thing of the past.
Why does not the particle’s movement damage the tube?
选项
A、The tube is tested before being used.
B、The friction can be neglected in the process.
C、It moves slowly to avoid friction.
D、The whole process can be monitored.
答案
B
解析
事实细节题。定位句表明,粒子的运动不会损坏纳米管的原因有两个:一是纳米管内壁十分坚固,二是小范围内的运动摩擦可以忽略不计。B)“该过程中的摩擦可以忽略不计”符合文意,故为本题正确答案。
转载请注明原文地址:https://jikaoti.com/ti/KvcFFFFM
0
大学英语四级
相关试题推荐
A、Becausethespeakerwasanartist.B、Becauseshewasalwaysahard-workingstudent.C、Becausetheartist’spaintingsappealto
ThecauseofthedeclineofNorthAfricaispopularlyattributedtoclimaticchanges,thetheorybeingthattheareabecamehott
Holidaysarecelebratedforallsortsofreasons.Somehonorheroes,otherscommemoratereligiousevents,butApril1ststandso
Holidaysarecelebratedforallsortsofreasons.Somehonorheroes,otherscommemoratereligiousevents,butApril1ststandso
A、Jacksurvivedtheaccident.B、Jackwastheonlyvictimoftheaccident.C、Jacksavedalltheotherpassengers.D、Itdidlittle
A、ItenablesEarthtostaywarmenoughforlifetosurvive.B、Itmakesyourcarmuchhotterinsidethanoutside.C、Itcanimprov
Luxembourglies______Belgium,GermanyandFrance.
SteamboatsbegantosailupanddowntheMississippiRiveratthebeginningofthe19thcentury,whichcontributedalottheare
Letushopethat______anuclearwar,thehumanracemightstillsurvive.
随机试题
一个进程被中断后,什么时间能再占用处理器是与_______的策略有关。
A.双肺满布干啰音B.局限性湿啰音C.双肺满布湿啰音D.两肺底湿啰音E.局限性干啰音支气管哮喘
根据蒽醌类化合物的酸性强弱不同,可用pH梯度萃取法进行提取与分离,其中酸性强(含COOH)的蒽醌类可溶于
可缓冲呼吸过程中肺泡气PO2和PCO2变化幅度的肺容量是
单位工程施工组织设计中最具决策性的核心内容是( )。
不满10周岁的未成年人是无民事行为能力人。()
一、注意事项1.申论考试是对应考者阅读理解能力、综合分析能力、提出和解决问题能力、文字表达能力的测试。2.作答参考时限:阅读资料40分钟,作答110分钟。3.仔细阅读给定资料,按照后面提出的“作答要求”作答。二、给定资料1
国家工作人员利用职务上的便利,侵吞、窃取、骗取或者以其他手段占有公共财物的,构成()。
(2015年单选39)“八议”是中国古代优遇官僚贵族的法律制度,即指八种人犯罪可经议罪减免刑罚。“八议”中“议宾”的对象是指()。
Weweregreatlyrelievedtolearnthat______(所有紧急事务都已处理完毕).
最新回复
(
0
)