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
2014-03-02
71
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, and 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 fight. 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 super-computer 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 ceils 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.
According to the passage, all of the following statements are true EXCEPT ______.
选项
A、The two strands making up DNA’s double helix can find each other easily in a complex chemical mixture
B、Evolution has solved the problem of building a computer smaller than a speck of dust a long time before
C、DNA not only programs cells to replicate themselves but also instructs them how to assemble individual molecules into new materials
D、The read-head components for computer hard drives are constructed by means of the technology known as a molecular beam epitaxy
答案
C
解析
选项A,可以从文章最后一句话看出。选项B,第5段"Building a super-computer... until one realizes that evolution solved such problems..."是说千万年前自然进化就解决了题中所说的问题。选项D在第4段最后一句提到。选项C,文中并没有提及这样一个问题,并且最后一段说这些生物大分子是self assembly(自我组装的),没有什么东西来instructs them,所以C是不符合原文的。所以此题选C。
转载请注明原文地址:https://www.kaotiyun.com/show/FjQO777K
0
考博英语
相关试题推荐
Statesareconsideringmajorchangesinprepaidcollegetuitionprograms-raisingprices,restrictingparticipationofcancelin
Thequestionofwhetherwarisinevitableisonewhichhasconcernedmanyoftheworld’sgreatwriters.Beforeconsideringthis
Intheeveningtheymetatthehotel,bothcontentwiththeirday,happytoeatameal______.togetheranddancealittleafterw
Althoughtoomuch【C1】______tothesun’sultravioletrayscancauseskincancer,sunshinemayhavea【C2】______effectagainstsome
Withaninitialinvestmentofonlytenthousanddollars,bothpartnershaveincreasedtheirmoney______.
TheUnitedStateshashistoricallyhadhigherratesofmarriagethanthoseofotherindustrializedcountries.Thecurrentannual
WhenDonaldarrivedforhisfirstgroup-therapysessionhewasinawheelchair,sufferingfrommalignantmelanomaandseverelyd
Becauseofvariousburdens,the1980sinEcuadorbecameadecadeof______Itwasmadeworsebybadfloodsin1983,thecollapseo
(61)Apple’sIpadmaybelatestandgreatesttechgadget,butoddlyenough,italsorepresentsareturntomodelthatmosttechc
AimlessnesshashardlybeentypicalofthepostwarJapanwhoseproductivityandsocialharmonyaretheenvyoftheUnitedStates
随机试题
降钙素的作用是
A.脉搏短绌B.水冲脉C.奇脉D.颈静脉搏动E.交替脉缩窄性心包炎,多表现为
关于硅酮结构密封胶的施工工艺检测环节,不需检测的项目是()。
对一些企业按计划完成程度不同分为三组:第一组为80%~100%,第二组为100%~120%,第三组为120%以上,则下列各项中选择正确的有()。
某仓库失窃,四个保管员因涉嫌被传讯。四人的口供如下:甲:我们四个人都没有作案乙:我们中有人作案丙:乙和丁至少有一个人没有作案丁:我没有作案 如果四个人中有两人说的是真话,有两个人说的是假话,则以下判
出行:雾霾:口罩
长期生活不规律会导致免疫细胞和胆固醇积聚在血管壁上,变成粥样斑块。这些斑块破碎时会形成血栓,血栓有可能脱落,沿血管流动。由于牙周病菌是一种厌氧菌,而血管中有大量氧气,因此牙周病菌单独进入血管并不能存活。但是,因为免疫细胞能够有效隔绝血管中的氧气,所以人们认
Wewerefrightenedbythe______ofthecrowd.
Wherewouldyoumostliketogoonvacation?Paris?London?TheAmazonRainforest?Eachofthesedestinationsisattractive.【B1
景泰蓝(cloisonne)是一种起源于元代北京的独特艺术。在明代的景泰年间,非常钟情于青铜制造技术(bronze-castingtechniques)的君王发展了色彩加工技术,并且创造了迎合东方审美的亮蓝色。在一次加工技术的突破之后,此君王的大部分日常
最新回复
(
0
)