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 nanotechnol-ogy. Yet over the past year also, a series
If you are a fan of science fiction, you’ve no doubt encountered the term nanotechnol-ogy. Yet over the past year also, a series
admin
2017-03-25
38
问题
If you are a fan of science fiction, you’ve no doubt encountered the term nanotechnol-ogy. 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 macromole-cules 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些过程或者生产产品的。
转载请注明原文地址:https://kaotiyun.com/show/iZGO777K
0
考博英语
相关试题推荐
Inaperfectlyfreeandopenmarketeconomy,thetypeofemployer—governmentorprivate—schoolhavelittleornoimpactont
ThetwoclawsofthematureAmericanlobsteraredecidedlydifferentfromeachother.Thecrusherclawisshortandstout;thec
IncomeinequalityintheUnitedStatesremainedrelativelystableforaperiodofnearlyfortyyears.Beginninginthe1970’s,h
Differentculturesaremoreproneto______certainillnessesbecauseofthefoodthatischaracteristicinthesecultures.
Thegirl_______whenshecouldn’tansweredthequestioninthepresenceofallherclassmates.
Thispolicygave______toprivatepropertyandledtodifferencesbetweentherichandthepoor.
ThesenatorofNewYorkcourtedblackvoters,consideredcrucialto_____theDemocraticpresidentialnomination,inaseriesofc
Hewasinextremestateofdistressanddepressionwhenheknewthathehad_____lungcancer.
Usually,companieswouldliketoemployexperiencedapplicants.Formanycollegestudents,theylaytheiremphasisonstudy,and
TheUKhaslongprideditselfonitsroadsafetystandards.Casualtyfiguresarelowcomparedwithmostotherindustrializedcou
随机试题
A.转肽酶B.转位酶C.释放因子D.核蛋白体在翻译过程中能识别终止密码的是
具有SRBC受体的细胞是
吡喹酮为
单纯性牙周炎局部治疗为()
A.心包摩擦音B.心脏杂音突然改变C.心前区舒张期杂音D.心前区收缩期杂音E.主动脉瓣区舒张期杂音
银行或其他金融机构工作人员吸收客户资金不入账的,可判20年以上有期徒刑。()
甲企业2017年产品单位售价为100元,变动成本率为60%,固定成本总额为150万元,利息费用为50万元。2018年预计产品的单位售价、单位变动成本、固定成本总额不变,所得税税率为25%(与往年一致),预计销售量将增加50%。甲企业过去5年的有
王某因劳动合同终止而失业,已办理登记并有求职要求,此系王某首次失业,已知王某与用人单位累计缴纳失业保险费满7年。王某领取失业保险金的最长期限是()。
注册会计师在测试X公司与采购交易相关的内部控制时发现的以下情况中,()最有可能表明采购交易完整性认定存在重大错报风险。
-1,2,3,-1,-10,-6,()
最新回复
(
0
)