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
22
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:https://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
Peterwon’tgowithJuliabecause______.[originaltext]M:Hello,Julia.Whyare
Theonlysurvivorofashipwreckwaswasheduponasmall,uninhabitedislan
Sincewearesocialbeings,thequalityofourlivesdependsinlargemeasur
下列各组词中,属于多义词的有()A.喜好、休息、吹牛、捣鬼 B.帽子、小鞋、辫
行动研究是在实际情境中,针对问题提出改进计划,通过在实践中实施、验证、改进而得到
下列因素中,不会影响固定资产有效工作时间的是()。A.轮班工作时间 B.工
出卖人根据合同约定将标的物运送至买受人指定地点并交付给承运人后,标的物毁损、灭失
已知逻辑函数的简化表达式为L=B⊕D,该函数至少有( )无关项。A.1个 B
吊耳使用要求,不正确的有( )A.设备出厂前应按设计要求做吊耳检测,并出具检测报
某施工企业瞒报生产安全事故,建设行政主管部门应依法对其处以()万元的罚款。A.
最新回复
(
0
)