北科大考研真题
北京科技大学历年数学分析考研真题汇编(2003-2017)
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北京科技大学 2013 年硕士学位研究生入学考试试题
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0 ，求曲线C
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面最远的点和
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试题编号： 613 试题名称：
数学分析
（共 2 页）
适用专业：
数学，统计学
北京科技大学《材料科学基础》考研真题强化教程
考点1：金属键，离子键，共价键，氢键，范德瓦耳斯力的定义。
例1（名词解释）：离子键。
例2：解释金属键。
例3：大多数实际材料键合的特点是（）。
A．几种键合形式同时存在B．以离子键的形式存在C．以金属键的形式存在考点2：金属键，离子键，共价键的特征。
例4：化学键中既有方向性又有饱和性的为（）。
A．共价键B．金属键C．离子键例5：原子的结合键有哪几种？各有什么特点？考点3：依据结合键对于材料的分类。
例6：解释高分子材料与陶瓷材料。
例7：试从结合键的角度，分析工程材料的分类及其特点。
例8：何谓陶瓷？从组织结构的角度解释其主要性能特点。
考点1：以米勒指数描述晶向和晶面1.1 晶面族例1：什么是晶面族？{111}晶面族包含哪些晶面？例2：请分别写出立方晶系中{110}和{100}晶面族包括的晶面。
1.2 晶面夹角和晶面间距例：面心立方结构金属的[100]和[111]晶向间的夹角是多少？{100}面间距是多少？1.3 晶带定理例1（名词解释）：晶带定理。
例4：晶面（110）和(111)所在的晶带，其晶带轴的指数为（）。
1.4 HCP的米勒指数例1：写出如图所示六方晶胞中EFGHIJE面的密勒-布拉菲晶面指数，以及EF、FG、GH、HI、IJ、JE各晶向的密勒-布拉菲晶向指数。
例2：写出如图所示六方晶胞中EFGHIJE晶面、EF晶向、FG晶向、CH晶向、JE晶向的密勒-布拉菲指数。
例3：六方晶系的[100]晶向指数，若改用四坐标轴的密勒指数标定，可表示为（）。
1.5 画晶向和晶面，面密度的求法例2：bcc结构的金属铁，其（112）晶面的原子面密度为9.94×1014atoms/cm3。
（1）请计算（110）晶面的原子面密度；（2）分别计算（112）和（110）晶面的晶面间距；（3）确定通常在那个晶面上最可能产生晶面滑移？为什么？（bcc结构铁的晶格常数为a=0.2866nm）1.6 晶向指数的意义例：一组数[uvw]，称为晶向指数，它是用来表示（）。
北科大材料考研试题
（3）脱溶分解对性能的影响 脱溶分解对材料的力学性能有很大的影响，其 作用决定于脱溶相地形态、大小、数量和分布 等因素。 一般来说，均匀脱溶对性能有利，能起到明显 地强化作用，称为“时效强化”或“沉淀强 化”； 而局部脱溶，尤其是沿着晶界析出（包括不连 续脱溶导致的胞状析出），往往对性能有害， 使材料塑性下降，呈现脆化，强度也因此下降。
①成分不变协同型长大②成分不变非协同型长大 ③成分改变协同型长大 ④成分改变非协同型长大 成分不变的相变无需溶质原子扩散，晶核长大速 度仅与界面点阵重构过程有关。协同型长大原子 调整位置的过程通常可以在很短的时间内完成， 所以晶核长大速度很快；而成分不变的非协同型 长大速度则受控于界面原子调整位置的速度，即 受界面过程所控制。
（3）、屈氏体(T): 片间距约小于200nm，形成于 600 ～ 500℃温度范围内。在光学显微镜下已很难 分辨出铁素体和渗碳体片层状组织形态。电镜观 察。 注意：珠光体、索氏体、屈氏体之间无本质区别， 都是铁素体和渗碳体片层相间组织，其形成温度 也无严格界线，只是其片层厚薄和片间距不同。
（1）共格界面 如果界面上的原子同时属于两相，即两相晶格 在界面上彼此完全衔接，界面上的原子为两相 共有，便可形成共格界面。存在一定的弹性应 力场，其大小取决于相邻两相界面，原子间距 a a 的相对差值δ＝ a 。 δ越大，弹性应变能 越大。共格界面的界面能很低。 （2）半共格界面 δ 增大，为了维持界面上的原子为两相所共有， 须由一系列调配位错进行调节，形成半共格界 面。半共格界面的界面能和弹性应变能介于共 格界面和非共格界面之间。
（3）非共格界面 当δ很大时，界面处两相原子根本无法匹配，形 成非共格界面。这种界面由不规则的原子构成， 厚度约3－4个原子层，性质与大角度晶界相似， 界面能较高而弹性应变能很小。 2界面能 固－固两相界面能比液－固两相界面能高。 一部分是形成新相界面时，因化学键变化引起 的化学能，另一部分时由界面原子的不匹配产 生的点阵畸变能。 界面能：共格界面＜ 半共格界面＜ 非共格界面
北京科技大学考研英语题目(含复试)
一As is vividly depicted by the drawing above, a boy is sleeping soundly① and comfortably in the sofa, with the television on, when his mother comes and turnsoff the television for him, blaming the boy for not having turned off the television again②。
This phenomenon can easily be found anywhere in our daily life. Many people are used to doing③ everything with the television on, not actually watching it at all. Such a habit can cause waste of much electricity and energy, and result in the emission of carbo n. This deviates from the popular concept of “low carbon life” — to reduce the emission of carbon, especially carbon dioxide, to protect our environment and realize sustainable development. According to statistics, if we can decrease the time for having the television on by one hour each day, we can deduce the amount of carbon emission by 4. 71 kilogram each month。
北京科技大学研究生英语考试真题
2004/6 Listening Comprehension1. A. No women were allowed to take part in it.B.Women were only allowed to watch the Games.C.Unmarried girls were allowed to compete with men.D.Unmarried women were allowed to watch itsomewhere.2. A. She needs to buy new clothes.B.She cares a lot about what to wear.C.The man doesn't work hard enough.D.The man should buy some new ties.3. A. Takes a hot bath. B. Takes a long walk.C. Has a few drinks.D. Has more coffee.4. A. They have a very close relationship.B.They don't spend much time together.C.They are getting along with each other better.D. They are generally pretty cold to each other.5. A. His sixth sense told him.B.He is unskillful with his present job.C.His present job pays too little.D.His present job is too demanding.6. A. The accident caused injury or loss of life.B.Seven people were killed in the accident.C.Many people from other cars came to help.D. A lot of vehicles were involved in the accident.7. A. 2754201. B. 2645310.C. 2745301.D. 2654310.8. A. She had no chance to speak.B.She was speechless.C.She talked a lot to the star.D.She saw too many people around the star.9. A. Because it tells the truth most of the time.B.Because it provides a lot of information.C.B ecause it is the top one on the list of newspapers.D. Because it is an inside newspaper.10. A. Because other scientists had raised questionsabout these claims.B.Because some of its scientists had made falseclaims before.C.Because the claims were very important to thestudy of physics.D.Because some of its scientists published too manypapers a year.11. A. He made up false data in the experiment tosupport his new findings.B.He used information from previous work tosupport his new findings.C.He denied other scientists' involvement in hisexperiments.D.He was not productive in writing scientific papers.12. A. They dismissed all Mister Schon's publications.B.They asked Mister Schon to apologize to thepublic.C.They recalled Mister Schon's title as a Nobel Prizewinner.D.They removed Mister Schon from his position.13. A. The winner should write a report to the committeeof the foundation.B.The winner should report to the committee beforethey spend the money.C.The winner should not be a government official.D.The winner should be nominated by thefoundation's directors.14. A. For her achievements in environmental protection.B.For her achievements in developing computersoftware.C.For her achievements in developing warships.D.For her achievements in developing robots.15. A. He was recognized as a genius by the foundation'sdirectors.B.He helped the developing countries to fightagainst earthquakes.C.He helped the third world countries to developquickly.D.He ran a non-profit international organization.16.What did the several hundred college studentscompete to build recently in Washington D.C.? 17.Which department in the United States organized thecompetition?18.How many teams took part in the competition?19.How much did each team spend on equipment andother materials?20.What is the purpose of the competition?Transcript (Jun 20, 2004)1.A: I heard no women were allowed to take part in theOlympic Games in ancient Greece. Is that true? B: But somewhere unmarried girls were allowed to watch or even compete in the Games in those days.They could compete in a separate festival.Q: From this conversation what do we learn about Olympic Games in ancient Greece?1. A. No women were allowed to take part in it.B.Women were only allowed to watch the Games.C.Unmarried girls were allowed to compete with men.D.Unmarried women were allowed to watch itsomewhere.2.A: Now you are in the new company, you may needto buy some new clothes.B: As long as I work hard, nobody cares what I wear.But you may rethink your ties.Q: What does the woman mean?2. A. She needs to buy new clothes.B.She cares a lot about what to wear.C.The man doesn't work hard enough.D.The man should buy some new ties.3.A: What do you usually do when you feel tired?B: I usually listen to some classical music, or take a long hot bath. What about you?A: I usually relax with a few drinks or drink more coffee to keep myself going.Q: What does the woman usually do when she feels tired?3. A. Takes a hot bath. B. Takes a long walk.C. Has a few drinks.D. Has more coffee.4.A: How do you get along with your partner?B: Generally our relationship is pretty good but we both are aware of the importance of spending timealone.Q: What is the relationship between the man and his partner like?4. A. They have a very close relationship.B.They don't spend much time together.C.They are getting along with each other better.D.They are generally pretty cold to each other.5.A: It seems to me that you will switch to another job. B: How do you know?A: My sixth sense told me.B: You are actually right. I'm fed up with working anunskilled job for a minimum wage.Q: Why did the man want to change his job?5. A. His sixth sense told him.B.He is unskillful with his present job.C.His present job pays too little.D.His present job is too demanding.6.A: Did you watch the report about the accident indowntown?B: No. Where was it?A: It was on seventh street. It was a huge wreck and I saw a lot of ambulances at the scene.Q: What do we learn about the accident?6. A. The accident caused injury or loss of life.B.Seven people were killed in the accident.C.Many people from other cars came to help.D. A lot of vehicles were involved in the accident.7.A: Hello. My name is Nathaniel Mumford. I'm astudent of Professor Cohen's. May I speak to himplease?B: Oh, Professor Cohen is at a conference at the moment, but if you leave your phone number hemay call you back when he returns.A: My phone number is 2745301. Thank you for you help.Q: What is the phone number of the student?7. A. 2754201. B. 2645310.C. 2745301.D. 2654310.8.A: Did you speak to the famous star?B: I wanted to, but I was unable to speak when I wasface to face with him.A: Well, many people do that. Before they meet their favorite star they seem to have a lot to say. But when they actually meet them, they can't say anything. Q: What happened to the woman when she met the famous star?8. A. She had no chance to speak.B.She was speechless.C.She talked a lot to the star.D.She saw too many people around the star.9.A: Why are you so keen on this newspaper?B: It's really informative and it is the top one among those offering inside stories.Q: Why does the man like the newspaper?9. A. Because it tells the truth most of the time.B.Because it provides a lot of information.C.B ecause it is the top one on the list of newspapers.D.Because it is an inside newspaper.Mini-Talk OneInvestigators from Bell Labs Murray Hill, New Jersey have found that claims made by some scientists at the laboratory were not based on fact. The investigators dismissed results from a number of studies published between 1998 and 2001. Bell Labs appointed a committee to investigate the wrongdoing after other scientists raised questions about the claims. Some of the claims were once said to be major developments in the study of physics. They included a claim that scientists had created the smallest device to carry electric current ever made.The committee identified at least sixteen examples of scientific wrongdoing. It placed the blame on one Bell Labs physicist, Jan Hendrik Schon. Mr. Schon told the committee that he had no written records of the laboratory experiments. He also said much of the information in his computer had been destroyed.The investigators found that Mr. Schon used information from earlier work to support his findings. They said his did this without the knowledge of the other scientists involved in the experiments. The investigators noted that Mr. Schon and his group produced an average of one scientific paper every eight days. For most scientists, a few papers a year is considered productive.After the committee's report was released, Bell Labs immediately dismissed Jan Hendrik Schon from his position. He was once thought to be a future Nobel Prize winner. After his dismissal, Mr. Schon admitted he had made mistakes in his scientific work. He said he regretted those mistakes.10.Why did Bell Labs appoint a committee to investigatesome of the claims made by its scientists?10. A. Because other scientists had raised questionsabout these claims.B.Because some of its scientists had made falseclaims before.C.Because the claims were very important to thestudy of physics.D.Because some of its scientists published too manypapers a year.11.What did the committee find out when theyinvestigated Mr. Schon?11. A. He made up false data in the experiment tosupport his new findings.B.He used information from previous work tosupport his new findings.C.He denied other scientists' involvement in hisexperiments.D. He was not productive in writing scientific papers.12.What did Bell Labs do after the committee's reportwas released?12. A. They dismissed all Mister Schon's publications.B. They asked Mister Schon to apologize to the public.C. They recalled Mister Schon's title as a Nobel Prizewinner.D.They removed Mister Schon from his position.Mini-Talk TwoThe MacArthur Fellowship is a program that honors individual men and women for their creativity. American businessman John MacArthur used his own money to establish the MacArthur Foundation in 1970. It began to operate after he died eight years later.To be considered for the award, a person must be nominated. And they should not hold an elective or an appointed office in government.Each year, several hundred people are appointed to propose nominations. A twelve-member committee studies information about those nominated to identify the great creativity in their work and proposes winners to the foundation's directors. The foundation does not require or expect reports from individual winners. It also does not ask them how the money will be used.Six hundred and thirty-five MacArthur Fellows have been named since the program started in 1981. Between 20 and 30 winners are named each year.The twenty-four winners this year work in many different areas. They include scientists, writers, and musicians. Daniela Ruth is a professor in Dartmouth College in New Hampshire. She is a computer scientist who develops robots that change shape to deal with changes in their environment.Brian Tucker from California is another winner. Mr. Tucker is an earthquake expert. He is the president of a non-profit group called GeoHazards International. His group works for local officials in developing countries to make their areas safer against earthquakes. Mr. Tucker says that being recognized as a MacArthur Fellow will make a huge difference for his company.13.Which of the following is one of the requirements fora MacArthur Fellowship winner?13. A. The winner should write a report to the committeeof the foundation.B. The winner should report to the committee beforethey spend the money.C. The winner should not be a government official.D.The winner should be nominated by thefoundation's directors.14.Why was Daniela Ruth awarded this year'sMacArthur Fellowship?14. A. For her achievements in environmental protection.B. For her achievements in developing computersoftware.C. For her achievements in developing warships.D.For her achievements in developing robots.15.Why was Brian Tucker given this year's MacArthurFellowship?15. A. He was recognized as a genius by the foundation'sdirectors.B. He helped the developing countries to fight againstearthquakes.C. He helped the third world countries to developquickly.D.He ran a non-profit international organization.Section CExperts say in the near future, many houses in the United States will be powered by energy from the sun. Many people in Washington D.C., recently were able to see what some of those homes might look like. Several hundred college students from across the country took part in a competition to see who could build the best solar-powered house. The United States Department of Energy organized the competition.Students from fourteen colleges and universities took part in this Solar Home Competition. Student teams competed in a series of ten contests to see who could design, build and operate the best house powered only by the sun. The solar homes were built on the National Mall, the grassy open area between the United States Capitol building and the Washington Monument. The solar houses were set up in the middle.Each team included at least twenty students of design, architecture and building sciences. The students gained the money to buy equipment and materials for their house.Each house cost as much as $250,000 to build.A solar-powered house has a roof designed to take in the heat of the sun and change it to energy. That power is then stored in a battery bank which supplies power to the whole house.As part of the competition, the teams were expected to spend most of the day in their homes doing normal activities. The activities used electricity powered by the sun. For example, the students cooked food, used computers, operated lights and washed clothes in machines. They even drove around the solar village in electric cars powered by a solar battery. The competition is designed to show Americans that solar energy works, because the use of solar energy in the United States is less than in other parts of the world. Only about 20,000 American homes are solar-powered.。
北京科技大学616中国通史考研真题及答案
北京科技大学616中国通史考研真题及答案——才聪学习网2021年北京科技大学科技史与文化遗产研究院《616中国通史》考研全套目录•全国名校中国史考研真题汇编（含部分答案）•全国名校中国近（现）代史考研真题汇编（含部分答案）说明：本科目考研真题不对外公布（暂时难以获得），通过分析参考教材知识点，精选了有类似考点的其他院校相关考研真题，以供参考。
•翦伯赞《中国史纲要（增订本）上》配套题库【名校考研真题＋章节题库＋模拟试题】•翦伯赞《中国史纲要（增订本）下》配套题库【名校考研真题＋章节题库＋模拟试题】•李侃《中国近代史》（第4版）笔记和典型题（含考研真题）详解•[预售]李侃《中国近代史》（第4版）配套题库【考研真题精选＋章节题库】说明：以上为本科目参考教材配套的辅导资料。
3．考研题库•[预售]2021年中国古代史考研题库说明：本部分为本科目考试内容的相关题库，并提供了详解。
•试看部分内容名校考研真题第1章史前时代一、单项选择题1我国境内发现的新石器时代文化遗址有六千多处，遍布黄河流域和长江流域。
其中江南地区迄今为止发现的最早的新石器遗址是（）。
[2014北京科技大学研]A．河姆渡文化B．仰韶文化C．马家窑文化D．红山文化【答案】A查看答案【解析】A项，河姆渡文化，1973年发现于浙江余姚河姆渡，是江南地区迄今较早的、最有代表性的新石器遗存。
B项，仰韶文化是新石器时代北方地区的文化。
C项，马家窑文化是位于黄河上游地区。
D项，红山文化分布在辽西及其附近地区。
2下列考古学文化中，与后来游牧文明有密切关系的是（）。
[20 13年统考真题]A．马家窑文化B．红山文化C．仰韶文化D．屈家岭文化【答案】Ｂ查看答案【解析】仰韶文化是新石器时代中期最有典型意义的文化，192 1年发现于河南渑池县仰韶村而得名。
和仰韶文化约略同时的主要有北方的红山文化、黄河上游的马家窑文化、长江流域的屈家岭文化等。
红山文化分布在辽西及其附近地区，契丹族在此兴起，建立契丹国。
北科大材料考研试题
（二）、螺位错
分类：有左、右旋之分，根 据螺旋面旋转方向，符合 右手法则（即以右手拇指 代表螺旋面前进方向，其 他四指代表螺旋面的旋转 方向）的称右旋螺型位错。
图2-12 螺位错形成示意图
（三）、混合位错
在外力作用下，两 部分之间发生相对滑移， 在晶体内部已滑移和未 滑移部分的交线既不垂 直也不平行滑移方向 （伯氏矢量b），这样 的位错称为混合位错。 如右图所示。
五、其他晶体的点缺陷
离子晶体中整体和局部都要求电中性，因此离子晶体 中的点缺陷稍微复杂。 离子晶体中的肖脱基点缺陷只能与等量的正离子空位 和负离子空位同时存在。 另外，由于离子晶体中负离子半径往往比正离子半径 大得多，负离子不易形成间隙原子，所以弗兰克尔 点缺陷只能是等量的正离子空位和正离子间隙原子。
补充几个需要理解的概念
多晶体:
实际应用的工程材料 中，哪怕是一块尺寸很小 材料，绝大多数包含着许 许多多的小晶体，每个小 晶体由大量的位向相同的 晶胞组成，而各个小晶体 之间，彼此的位向却不相 同。称这种由多个小晶体 组成的晶体结构称之为 “多晶体”。
补充ቤተ መጻሕፍቲ ባይዱ个需要理解的概念
晶粒：多晶体材料中每个 小晶体的外形多为不规则 的颗粒状，通常把它们叫 做“晶粒”。 晶界：晶粒与晶粒之间的 分界面叫“晶粒间界”， 或简称“晶界”。为了适 应两晶粒间不同晶格位向 的过渡，在晶界处的原子 排列总是不规则的。
第三章
晶体结构缺陷
晶体结构缺陷的类型
点缺陷
缺陷的 类型
其特点是在三维 方向上的尺寸都 很小，缺陷的尺 寸处在一、两个 原子大小的级别， 又称零维缺陷， 例如空位，间隙 原子和杂质原子 等。
线缺陷
北科大材料考研试题
τ ≈Gb/2R
推倒思路：1、作 用在位错上的力 F=T分量 2、ds/dθ=R 3、dθ很小时
第五节、位错与晶体缺陷间的交互作用
两平行螺型位错交互作用的特点是同号相斥，
异号相吸； 当两个刃型位错的柏氏矢量方向相同时，为 斥力，反之，为引力；情况相对螺型位错复 杂； 位错与点缺陷的交互作用： 柯垂尔气团 固溶强化 史氏气团
晶体中位错柏氏矢量可否是任意的，为何常用柏氏矢 量只有少数几个?(补充资料)
实际晶体中，位错的柏氏矢量不是任意的，
它应符合相应的结构条件和能量条件。 晶体结构条件是指柏氏矢量必须连接晶体中 一个原子平衡位置到另一个平衡位置；能量 条件是指柏氏矢量所表征的位错应尽量处于 最低能量。 因此，实际晶体中存在的位错及其柏氏矢量 只有少数几个。
a 6
a[001]
a 6
[110]
[121]+
[211]
课堂练习：书上4道例题！
位错环运动习题（补充资料）
参考答案
三 扩展位错（ extended dislocation ） 1 面心立方晶体中能量最低的全位错 2 〈110〉可以分 解为两个肖克莱不全位错： 1 a[101] 1/6a[211]+1/6a[112] 2 分解后将使位错能量减少1/6。这种由两个肖克莱不 全位错之间还夹着一片层错的位错称为扩展位错。
不全位错：
肖克莱（Shockley）不全位错和 弗兰克(Frank)不全位错； 在面心立方晶体中，由不均匀滑移造成的不 1 全位错，其柏氏矢量为 6 a〈211〉,称这种不 全位错为肖克莱不全位错； 肖克莱不全位错可以是刃型、螺型或混合型 位错，因其柏氏矢量在滑移面上，故肖克莱 不全位错可以滑移。.
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北 京 科 技 大 学
2011年硕士学位研究生入学考试试题
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试题编号： 802 试题名称： 控制工程基础 （共4页） 适用专业： 机械工程 说明： 所有答案必须写在答题纸上，做在试题或草稿纸上无效。
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一、（每小题2分，合计10分）判断题。
判断下列叙述是否正确。
（1）如果二阶系统的闭环极点是一对共轭复极点，则系统的超调量一定大于零。
（ ）
（2）采用负反馈形式连接后，一定能使干扰引起的误差逐渐减小，最后完全消除。
（ ）
（3）闭环系统的稳定性一定比开环系统好。
（ ）
（4）系统的稳态误差趋于∞，说明系统是不稳定的。
（ ）
（5）如果闭环系统的极点均为负的实数极点，则其阶跃响应是无超调的。
（ ） 二、（每小题2分，合计10分）选择题。
选择正确答案的序号。
（1）在通常的闭环控制系统结构中，系统的控制器和被控对象共同构成了（ ）。
（A ）开环传递函数 （B ）闭环传递函数 （C ）前向通道 （D ）反馈通道
（2）在二阶欠阻尼系统时域性能指标中，与无阻尼振荡角频率无关的是（ ）。
（A ）最大超调量 （B ）峰值时间 （C ）上升时间 （D ）调整时间
（3）已知系统的传递函数为1
51+s ，当系统的输入信号为()t t r ωsin 2=时，系统的稳态
输出信号为（ ）。
（A ）()()ωω5sin 2arctg t t c += （B ）()()ωω5sin 2arctg t t c -= （C ）()()ωωω
5sin 1
2522
arctg t t c ++= （D ）()()ωωω
5sin 1
2522
arctg t t c -+=
（4）已知系统的传递函数为
1
53+s ，则该系统的单位阶跃响应为（ ）。
（A ）5
1t e -- （B ）5
33t e -- （C ）5
55t e -- （D ）5
3t e --
（5）下面分别给出了四个系统的开环极坐标图，并且这四个系统的开环传递函数都没有右极点。
系统闭环后，不稳定的闭环系统有（ ）。
（A ）
（B ）
（C ）
（D
）
三、（20分）计算下图所示系统的等效传递函数
)
()(s R s C 。
四、（20分）已知图（a ）所示系统的阶跃响应曲线如图（b ）所示。
试确定系统参数1K ，2K 和a 的值。
五、（20分）已知最小相位系统的开环对数幅频特性如图所示，其中斜率的单位为dB/dec 。
解答下列问题：
（1）写出系统的开环传递函数。
（2）根据相位裕量判断闭环系统的稳定性。
（3）如果将开环对数幅频特性向左平移十倍频程，试讨论闭环系统稳定性的变化。
六、（20分）已知最小相位系统的开环对数幅频特性)(ωG L 和串联校正装置的对数幅频特性)(ωC L 如图所示，其中斜率的单位为dB/dec 。
解答下列问题： （1）写出该最小相位系统的开环传递函数)(s G ，并计算其相位裕量γ。
（2）写出串联校正装置的传递函数)(s G C 。
（3）在答题纸上画出串联校正后的系统开环对数幅频特性曲线)(ωGC L 。
七、（25分）已知控制系统的传递函数方块图如图所示，其中01>K ，02>K ，0≥β。
试分析：
（1）当β值增大时，系统的稳定性如何变化？
（2）当β值增大时，系统的最大超调量和调整时间如何变化？
（3）如果输入信号为t a t r =)(，当β值增大时，系统的稳态误差如何变化？
八、（25分）复合控制系统结构图如图所示，其中1K ，2K ，1T ，2T 均为大于零的常数。
解答下列问题：
（1）当闭环系统稳定时，确定参数1K ，2K ，1T ，2T 应满足的条件。
（2）当输入为at t r =)(时（其中a 为常数），选择最简单的校正装置)(s G C ，使得系统无稳态误差。