用电铸加工方法制作模具型腔时,为了获得较高的机械强度和硬度、较小的表面粗糙度,电铸材

题型:单项选择题

问题:

用电铸加工方法制作模具型腔时,为了获得较高的机械强度和硬度、较小的表面粗糙度,电铸材料应采用()。

A.电铸镍

B.电铸同

C.电铸铁

D.电铸铝

考点:模具制造工高级模具制造工高级模具制造工题库
题型:单项选择题

There are no exact differences between physics and other natural sciences because all sciences overlap(重叠).In general,however,physics is the scientific study of forces and qualities such as heat,light,sound,pressure,gravity and electricity,and the ways they affect other objects.

One major branch of physics deals with the states of matter—solids,liquids and gases and with their motions.The pioneer achievements of Galileo,Kepler and Newton dealt with solid masses of matter in motion.Such studies deal with forces acting on moving objects.It is the subject of mechanics and belongs to the branch of mechanics called dynamics,the study of matter in motion.This large topic includes not only the motions of stars and ping-pong balls but also the motions of the water pumped by a fire engine and those of the air passing through the jet engine of an airplane.

A branch of mechanics is statics(静力学),the study of matter at rest.The designs of buildings and bridges are examples of problems in statics.Other branches of physics are based on the different kinds of energy,which interact with matter.They deal with electricity and magnetism(磁力),heat,light,and sound.From these branches of physics scientists find clues(线索) which have revealed(揭示) the constructions of atoms and how the atoms react to various kinds of energy. This knowledge is often called the basis of modern physics.Among the many subdivisions(细的分支)of modern physics are electronics and nuclear physics.Physics is closely related to engineering.A person who uses knowledge of physics in solving everyday problems is often called an engineer.For example,electricity is one of the branches of physics;and an electrical engineer is a man who uses the “natural laws” of electricity to help in designing and electric generator(电动机).

小题1:Physics is not exactly different from other natural sciences because_________.

A.physics and other natural sciences have parts in common

B.it is the scientific study of forces and qualities such as heat,light and sound

C.it studies the ways in which forces and qualities affect other objects

D.it is a part of other natural sciences小题2:The following statements are included in the study of dynamics except_________.

A.the design and construction of skyscrapers

B.the motions of heavenly bodies

C.the motions of water pumped by a fire engine

D.the motions of the air passing through the jet engine of an airplane小题3:Among many branches of modern physics is _________.

A.states

B.electricity

C.electronics

D.mechanics小题4:This knowledge” in Paragraph Three refers to_________.

A.electricity and magnetism,light and sound

B.the construction of atoms and their reactions to various kinds of energy

C.the basis of modern physics

D.electronics and nuclear physics

题型:单项选择题

能源是人类生活和社会发展的基础,研究化学反应中的能量变化,有助于更好地利用化学反应为生产和生活服务。阅读下列有关能源的材料,回答有关问题:

(1)从能量的角度看,断开化学键要吸收能量,形成化学键要放出能量。已知拆开1 mol H-H键、1 mol I-I、1 mol H-I键分别需要吸收的能量为436 kJ、151 kJ、299 kJ。则由氢气和碘单质反应(H2+I2=2HI)生成1 mol HI需要             (填“放出”或“吸收”)      ___ kJ的热量。

(2)在生产和生活中经常遇到化学能与电能的相互转化。

在如图甲装置中,负极电极反应式为                      ,发生的是   反应(填“氧化”或“还原”,下同)。正极电极反应式为                              ;总反应的离子方程式为                                           

(3)若用氢氧化钾溶液做电解质溶液,用氢气做燃料,空气做氧化剂制成燃料电池,其负极反应式为                    ;正极反应式为                                   。当有标状下2.24L氢气消耗时,另一极消耗氧气的物质的量为        

(4)在如下图所示的原电池中,铝做        极,导线上电子由       极流向       极。

题型:单项选择题

使用局麻药,下列哪种情况易发生惊厥()。

A.局麻药在安全剂量内

B.局麻药中加用肾上腺素

C.尽量使用低浓度局麻药

D.C02蓄积

E.辅助全麻药

题型:单项选择题

绝缘材料具有良好的()性能,即有较高的()电阻和耐压强度。

题型:单项选择题

我国某空调制造厂欲引进国外先进技术生产空调,经与美国一家空调公司协商,达成共同投资开办中外合资经营企业的协议。该协议的主要内容包括,双方投资总额为400万美元,其中注册资金为200万美元;中方的空调制造厂以货币、厂房、土地使用权出资,出资额为150万美元;外方以设备和空调生产的专利技术作价100万美元作为出资,以合营企业名义向中国银行贷款150万美元作为对合资企业的投资,此笔贷款由拟设立的合营企业所在地的市财政局提供担保;在合营期内如合营双方认为有必要时,可在协商一致的基础上适当减少合营企业的注册资本。
审批机构在审查合同时,提出了协议存在的问题,经修改后,签发了批准证书。后经登记,该合营企业正式成立。
要求:据上述内容,分别回答以下问题:
(1)该合资经营企业协议中存在哪些不符合法律规定的地方
(2)假定合营企业经营两年后,经董事会会议决定,从利润中拨出10万美元先行返还美国公司的投资,此决议是否正确为什么
(3)假定不允许外方先行收回投资,外方可否将其所持股份转止给一个英国企业

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