首页
登录
职称英语
If you are a fan of science fiction, you’ve no doubt encountered the term na
If you are a fan of science fiction, you’ve no doubt encountered the term na
游客
2025-03-29
19
管理
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. [br] 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:http://tihaiku.com/zcyy/4016943.html
相关试题推荐
Ifyouareafanofsciencefiction,you’venodoubtencounteredthetermna
Ifyouareafanofsciencefiction,you’venodoubtencounteredthetermna
Thenewly-builtScienceBuildingseems______enoughtolastahundredyears.A、so
Inthelate19thcentury,JulesVerne,themasterofsciencefiction,foresawma
SomuchofmodernfictionintheUnitedStatesisautobiographical,andsomuch
Inscience,atheoryisareasonableexplanationofobservedeventsthatare
Inscience,atheoryisareasonableexplanationofobservedeventsthatare
Inscience,atheoryisareasonableexplanationofobservedeventsthatare
Inscience,atheoryisareasonableexplanationofobservedeventsthatare
Inscience,atheoryisareasonableexplanationofobservedeventsthatare
随机试题
Asapsychotherapistwithmanypatientsintheir20’s,Ican______thefacttha
圆管层流运动过流断面上速度分布为(式中r0为圆管半径):
学龄儿童应该合理食用各类食物,取得平衡膳食,一日中午餐热量占一日总热量的( )
在PowerPoint中放映当前幻灯片的快捷键为( )。A.Shift+F5
共用题干 DarkForcesDominateUniverseThee
覆冰天气时,观察外绝缘的覆冰厚度及冰凌桥接程度,覆冰厚度不超10mm,冰凌桥接长
下图是一块前后两面临街的矩形土地,总深度为30.00m,前街路线价(土地单价)为
工程质量控制关键点的文件中,不包括()A.质量控制关键点明细表 B.工序
(2021年真题)缆索吊装松索应按()顺序。A.拱脚段扣索、次拱脚段扣索、起重索
在某工程网络计划中,已知工作M自由时差为2天,总时差为5天,监理工程师检查实际进
最新回复
(
0
)