皮皮学,免费搜题
登录
搜题
【单选题】
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. It can be inferred that Richard Feynman has been ______ now.
A.
dead
B.
decent
C.
prominent
D.
popular
拍照语音搜题,微信中搜索"皮皮学"使用
参考答案:
参考解析:
知识点:
.
..
皮皮学刷刷变学霸
举一反三
【单选题】在选定一个文件或文件夹后,下列的操作中不能修改文件或文件夹名称的是()。
A.
在“文件”菜单中选择“重命名”命令,然后键入新的名字再按回车键
B.
按右键,在打开的快捷菜单中选择“重命名”命令,然后键入新的名称再回车
C.
用鼠标左键单击已选定的文件或文件夹的名称,然后键人新的名字再回车
D.
用鼠标左键单击该文件或文件夹的图标,然后键入新的名字再回车
【多选题】坚定实施区域协调发展战略指的是:
A.
统筹推进东部率先发展
B.
西部大开发
C.
中部崛起
D.
东北振兴
【单选题】统计质量管理的特点是什么( )
A.
事后的、静态的
B.
事中的、动态的
C.
事前的、静态的
D.
事中的、静态的
【多选题】掺混合材硅酸盐水泥的性能表现为 ( ) 。
A.
快硬早强
B.
耐海水腐蚀
C.
耐硫酸盐腐蚀
D.
抗冻性更优
E.
水化热更高
F.
更适合大体积混凝土
【单选题】猪的临床检查中群体检查的基本原则是
A.
静态→饮食状态→动态
B.
动态→静态→饮食状态
C.
饮食状态→静态→动态
D.
静态→动态→饮食状态
E.
饮食状态→动态→静态
【单选题】科学性原则是指创业决策要尽量符合()规律。
A.
自然
B.
社会发展
C.
经济
D.
经营管理活动本身
【简答题】l 自选一个主题,制作一部完整的微电影 l 将素材、项目文件及生成的电影文件一起压缩成 rar 格式上传 l 上传作业: l 文件大小尽量控制在 50M 以内
【判断题】( )粗齿锯条使用于锯削硬材料或较小的切面,细齿锯条使用于锯削软材料或较大的切面。
A.
正确
B.
错误
【单选题】关于静态投资和动态投资的区别与联系的表述中,不正确的是( )。
A.
动态投资包含静态投资
B.
动态投资是静态投资的唯一组成部分
C.
静态投资是动态投资的计算基础
D.
静态投资是动态投资最主要的组成部分
【多选题】掺混合材硅酸盐水泥的性能表现为( )。
A.
块硬早强
B.
耐海水腐蚀
C.
耐硫酸盐腐蚀
D.
抗冻性更优
E.
水化热更高
F.
更适合大体积混凝土
相关题目: