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
29
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
Inaperfectlyfreeandopenmarketeconomy,thetypeofemployer—governmentorprivate—schoolhavelittleornoimpactont
Heisholdinga______positioninthecompanyandexpectstobepromotedsoon.
AlthoughmanypeoplespeakEnglish,theydon’tpronounceitorspellthewordtheyusethesameway.TheUnitedStates,in【C1】__
LikenessesofBuddhaarethesedayssocommonplace—thecasualadornmentoffashionablespas,fusionrestaurantsandParisiann
【T1】HalfwaythroughthesemesterinhismarketresearchcourseatRoanokeCollegelastfall,onlymomentsafterannouncingapol
Thewonderswhichmedicalworkershavealreadybroughtaboutinthediagnosisandtreatmentofdiseasesuggestthatatimemayc
Thethreemostimportantissues(ofconcernto)citizenstodayare(prisonreform),(abusingchildren),andtoxic(waste).
______isthequestionofusingexistingresourcestoproduceoriginalandbeneficialsolutions,ideasorproducts.
Thesolutionwassimple:gasthebuildingwithahallucinogenandputtheterroriststosleepbeforetheycould_____thebombsin
Tomaintainaleadingpositioninthemarket,companieshavetodevelopproductswhicharecheaper,more_____andmorereliablet
随机试题
符合法定条件、标准的,申请人有依法取得行政许可的平等权利,行政机关不得歧视()
对鉴别是否肾小球源性血尿最有意义的是
选择产品定价的特点是()。
气浮过程的必要条件不包括()。
工程网络计划按工作持续时间的特点可划分为( )网络计划。
S有限责任公司系外商投资企业,确定的记账本位币为人民币。20×7年1月2日,S有限责任公司收到外商投入的外币资本400000欧元,当日的即期汇率为:1欧元=10元人民币。中外双方签订的投资合同中约定汇率为:1欧元=9.8元人民币。当月的平均汇率为1欧元=1
“超额贷款损失准备可计入部分”属于商业银行资本中的()。
简述音乐的审美特征
【H1】【H12】
A、TheinaccessibleInternet.B、Theservicequality.C、Theannualincome.D、Therailnetwork.B
最新回复
(
0
)