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
66
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.
It can be inferred that Richard Feynman has been______now.
选项
A、dead
B、decent
C、prominent
D、popular
答案
A
解析
本题的四个选项中,只有A项为正确答案。这可从文中第二段的“late physicist Richard Feynman”推知,late是“已故的”意思,说明Richard Feynman已经去世了。
转载请注明原文地址:https://kaotiyun.com/show/ZZGO777K
0
考博英语
相关试题推荐
Wearewritingtothemanager______therepairsrecentlycarriedoutattheaboveaddress.
Citiesdevelopasaresultoffunctionsthattheycanperform,somefunctionsresultdirectlyfromtheingenuityofthecitizenr
Tobe______Icouldn’tunderstandwhathewasgettingat.Ifyouwantedtoknowyou’dbetterasksomeoneelse.
Couldamechanicaldeviceever______humanintelligence-theultimatetestbeingwhetheritcouldcausearealhumantofallin
Everyyearanumberofstudentsgraduatefromtheschoolwhichwill______newstudentsthefirstweekinSeptember.
It’saseriouscrimethatpeople____goodsoutofChinatoavoidpayingcustomsduty.
Youaretowriteacompositionofnolessthan250wordsanddoyourcompositionneatlyontheAnswerSheet.Ypurcompositionsh
ThanksinnosmallparttoAlGoreandhisfilmproducers,theAmericanpubliciswakinguptotheseriousnessofglobalwarming
Inadditiontoredistributingincomes,inflationmayaffectthetotalrealincomeandproductionofthecommunity.Anincreasein
Afterthe______yearof1957,thebirthrateinCanadabegantodecline.
随机试题
心脏病孕妇最危险时期是
Environmentalofficialsinsistthatsomethingbedoneto______acidrain.
A.肉苁蓉B.山药C.何首乌D.石斛E.麦冬既润肺养阴,又清心除烦的药是
根据《建筑工程施工质量验收统一标准》GB50300—2013,对涉及结构安全和使用功能的重要分部工程应进行()。
社会工作的专业使命是()。[2009年真题]
合作
“人不信于一时,则不信于一世。”诚信并不遥远,诚信就在身边。实践每一句诺言,不迟到、不说空话、不作弊,让诚信融入我们的学习,让诚信渗入我们的生活。培育和践行诚信意识的哲学依据是()。①诚信是实现人生价值的必由之路、根本途径②正确的价
根据以下资料,回答116-120题。2008年上半年贵州农民人均生活现金消费支出为700.92元,考虑价格因素增长5.5%;城镇居民人均生活消费支出为4086.28元,比上年同期名义增长8.46%。支出增加的同时其结构也发生了一些变化。
(2014浙江)刚刚开学一个多星期,一名正在参加军训的大学生就将一大包衣服和七双袜子打包寄回家,让家人帮着洗,然后再寄回去。这则消息毫无悬念地引发了舆论的一阵喧哗,与以往类似的事情一样,痛心疾首者铺天盖地,上纲上线痛批中国教育的也不在少数。中国的校园总能不
如果一个过程不包含RETURN语句,或者RETURN语句中没有指定表达式,那么该过程:
最新回复
(
0
)