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
If you are a fan of science fiction, you’ve no doubt encountered the term nanotechnology. Yet over the past year also, a series
If you are a fan of science fiction, you’ve no doubt encountered the term nanotechnology. Yet over the past year also, a series
admin
2013-01-29
41
问题
If you are a fan of science fiction, you’ve no doubt encountered the term nanotechnology. Yet over the past year also, a series of breakthroughs have transformed nanotech from sci-fi fantasy into a real world. Applied science, in the process, inspired huge investments by business, academia, and government. In industries as diverse as health care, computers, chemicals, and aerospace, nanotech is overhauling production techniques, resulting in new and improved products, some of which may already be in your home or workplace.
The inspiration for nanotech goes back to a 1959 speech by the late physicist Richard Feynman, then a professor at the California Institute of Technology, titled "There’s Plenty of Room at the Bottom. " Four decades later, Chad Mirkin, a Chemistry professor at Northwestern University’s $ 34 million nanotech center, used a nanoscale device to etch most of Feynman’s speech onto a surface the size of about 10 tobacco smoke particles.
What accounts for the sudden acceleration of nanotechnology? A key breakthrough came in 1990, when researchers at IBM’s Almaden Research Center succeeded in rearranging individual atoms at will. Using a device’ known as a scanning probe microscope, the team slowly moved 35 atoms to spell the three-letter IBM logo, thus proving Feynman right. The entire Logo was less than three nanometers.
Soon, scientists were not only manipulating individual atoms but "spray painting" with them as well. Using a tool known as a molecular beam epitaxy, scientists have learned to create ultra fine films of specialized crystals, built up one molecular layer at a time. This is the technology used today to build read-head components for computer hard drives.
The next stage in the development of nanotechnology borrows a page from nature. Building a supercomputer no bigger than a speck of dust might seem an impossible task, until one realizes that evolution solved such problems more than a billion years ago. Living cells contain all sorts of nanoscale motors made of proteins that perform myriad mechanical and chemical functions, from muscle contraction to photosynthesis. In some instances, such motors may be re-engineered, or imitated, to produce products and processes useful to humans.
How are these biologically inspired machines constructed? Often, they construct themselves, manifesting a phenomenon of nature known as self assembly. The macromolecules of such biological machines have exactly the right shape and chemical binding preferences to ensure that when they combine they will snap together in predesigned ways. For example, the two strands that make up DNA’s double helix match each other exactly, which means that if they are separated in a complex chemical mixture, they are still able to find each other easily.
Which of the following is the function that nanoscale motors perform?
选项
A、rearranging individual atoms.
B、manipulating individual atoms.
C、producing products and process.
D、photosynthesis and muscle concentration.
答案
C
解析
本题的四个选项中,只有C项为正确答案。这可从文中第五段的第三、四句话“Living cells contain all sorts of nanoscale motors...useful to humans. ”推知,即nanoscale motors是用来完成诸如肌肉收缩和光合作用这样一些过程或者生产产品的。
转载请注明原文地址:https://jikaoti.com/ti/r9qYFFFM
0
考博英语
相关试题推荐
FrictionbetweenAmerica’smilitaryanditscivilianoverseersisnothingnew.America’s220-yearexperimentinciviliancontrol
Computersareoftenhardtorelateto,frustratingalotofpeople.AppleComputerInc’sMacintosh,withitsgraphicalsymbols,
Computersareoftenhardtorelateto,frustratingalotofpeople.AppleComputerInc’sMacintosh,withitsgraphicalsymbols,
Whatismeant【51】theword"friend"?Thedictionary【52】itas:."oneattachedto【53】byaffectionoresteem".Americansuset
Whatismeant【51】theword"friend"?Thedictionary【52】itas:."oneattachedto【53】byaffectionoresteem".Americansuset
Whatismeant【51】theword"friend"?Thedictionary【52】itas:."oneattachedto【53】byaffectionoresteem".Americansuset
Science,inpractice,dependsfarlessontheexperimentsitpreparesthanonthepreparednessofthemindsofthemenwhowatcht
Scienceisadominantthemeinourculture.Sinceittouchesalmosteveryfacetofourlife,educatedPeopleneedatleastsome
MargheritaisaLondongirlandarrivingatCapitalwaslikecominghome."IgrewuplisteningtoCapitalRadio,"shesays."Peo
Globalizationisaphenomenonandarevolution.Itissweepingtheworldwithincreasingspeedandchangingthegloballandscape
随机试题
此例可能的诊断是对确定手术适应证最有意义的检查是
下列关于溶血性贫血的描述中,正确的是
糖尿病患者注射正规胰岛素的时间是
下列关于线粒体氧化磷酸化解偶联的叙述,正确的是
下列以“部”为计量单位的是()。
客户的证券交易委托由证券营业部业务员审查后,将委托指令通过终端机输入交易所计算机主机的方式是有形席位申报。( )
单位存入现金时,商业银行的借记科目应是()。
发展我市旅游要抓好哪些工作?
“文化冲突论”是____________提出的。(复旦大学2012)
(2012下集管)在各种绩效报告工具或技巧中,通过______方法可综合范围(或资源)和进度信息作为关键因素。
最新回复
(
0
)