三峡大学 研究生入学考试试题
考试科目： 电子技术基础
（答案必须写在答题纸上，满分150分，考试时间 一、填空（本题30分）
1. 某电路中流过晶体二极管的直流电流为 2mA 二极管的微
变等效电阻为 __________ Q 。
2. 测得工作在放大电路中的晶体三极管电流如图 1所示，该
管是 __________ ，1、2、3脚依次为 __________ 、 __________ 、
__________ , B 为 _____________ 。
3. 用示波器观察PNP t 共射单级放大器输出电压得到图 2所示三
种失真波形，
试指出失真类型a: _________ , b: __________ , c: ________ ，增大R b 可消除
_______ 失真，增大RR 可消除 _________ 真，减小B 可同时消除 _______ 真。
J
v D
/
厂
\
厂
/ \
z -
\ ,
vZ
3 t
\/
3 t [\
c
s t
4. 电流串联负反馈放大器是一种输出端取样量为
输入端比较
量为 _____________ ■勺负反馈放大器，它使输入电阻 _________________ ，输出端电 阻 ____________ 。
5. 一个桥式整流滤波电路如图3所示，已知氏=20方sin ■ t （V ），当电容C 因
虚焊未接上，U 0端对应的直流电压平均值为 __________ 有电容C
第1页共4页
3小时）
0. 1 2
图1
但R_=:则U0
为_______ ，有电容C且R=：：，但有一个二极管因虚焊开路则U0为_______ 。
、（本题10分）
、（本题15分） 电路如图4所示。
1. 指出其反馈组态；
2.对于理想运算放大器,图4电路的A uf 和R f 是多大? 五、（本题10分）
图6是一种小型接近开关的振荡电路，若电路不能振荡，请说明其原因, 并改正。
108
s 已知 A （s ） =（S . e 2）（s 105
）
试画幅频波特图，指出f H, f L 和A o 3.该电路有何特点?
o
O
第3页
六、判断题(本题24分，正确画V错误画X)
1.(1100.1001) 2=(14.44) 8
2.(377) 8=(011111111)2
3.(1100100) 2=(100) 10
4.(CF) 16=(11011111)2
5.正逻辑的约定是：高电平为0,低电平为1。
6.已知F1= A ? BC，其对偶式F'= A (B C)
7.已知F2=AB CD，其反函数F^(A B)(C D)
8.(A B C)(A B C)(A B C) = B AC
七、选择题（本题16分）
1.若将一TTL异或门（输入端为A，B）当作反相器使用，则A，B端应________ 连接。
（a）A或B中有一个接1 （b）A或B中有一个接0
（c）A和B并联使用（d）不能实现
2.单稳态触发器的主要用途是 _________
（a）整形、延时、鉴幅（b）延时、定时、整形
（c）整形、定时、寄存（d）延时、定时、存储
3. _____________________________________________ 用8K*8位的EPROM构成64K*8位存储器，共需要_________________________ EPROM，系统需
要____ 址译码以完成寻址操作。
（a）8 片，64位（b）10片，16 位
（c）16 片，15 位（d）8 片，16 位
4.某计数器的状态转换图如图7所示，它是—计数器，采用_________ 编码。
（a）十进制减，2421 （b）十进制减，5421
（c）十进制加，5421 （d）十进制加，8421
------ C ppgj^：i----------------------- i：Cffl^：l—<^0100 1100 1001 1000
第4页
八、（本题15分）
用集成3线一8线译码器74LS138和与非门设计一个全加器，设A i为被加数，B i为加数，低位进位为C i-i，和为S i，向高位进位为C i。
Y o Y l 丫2 丫3 丫4 丫5 丫6 丫7
74LS138
A 2 A i A o G i G2 G3
III III
图8
九、（本题10分）
由D触发器和与非门组成的单脉冲产生器的逻辑电路如图9所示，时钟CP 和开关K的波形已知，试画Q A、Q B、Q的波形。
CP
_ L
K
'皿 ___________ /儿图g
十、（本题10分）
由555定时器构成锯齿波发生器如图10所示。锗管T 的V BE 可忽略，输 入触发脉冲V i 的波形已知，求电容充电电流和电容电压由0到最大值所需时间, 并定量画出u c 的波形。
--- T ---------------- T ----- T ―c Vcc （9Y ）
2KriR s X y
riRi
15K
Rz
30K
a 01 a
U i (V)
9V —
一 ------------------
H --------- J -------- L=! ----- , t
图10
555
0.5mS
long-distance education long-distance education, It is called network education in the file that released by department of education has introduced some , or called contemporary and long-range education network education. It refers to the use of TV and the Internet and other media teaching mode, the remote education is a very popular teaching model, because it broke through the time and space boundaries, accommodation in the school is different from the traditional teaching mode. Using this kind of teaching model of students, do not need to a specific location, anywhere. Students can also through television and radio, Internet, coaching line, a variety of different methods, such as mutual learning. Online learning has superior side, there are also some disadvantages. Learners can not adapt to the network teaching mode. Network education lack of interactivity and authenticity. On the BBS of the remote education, many netizens agree that network education's biggest drawback is the lack of interactivity and authenticity. In network education, between students and students, between students and the teacher only through BBS, E-mail or other network communication tools to communicate, people had built up a relationship is a kind of virtual environment of interpersonal relationships, interpersonal communication gradually from direct to indirect, from the diversification to the simplification, lost the traditional relationship between university students directly group consciousness gradually indifference. Education of students by this way, the collective idea and the spirit of solidarity and collaboration as generally traditional college students, is not conducive to the development of individuals and society.
ad if 命 封 线 密
A. some modern women prefer a life of individual freedom. B. the family is no longer the basic unit of society in present-day Europe. C. some professional people have too much work to do to feel lonely. D. Most Europeans conceive living a single life as unacceptable. 5.What is the author’s purpose in writing the passage? A. To review the impact of women becoming high earners. B. To contemplate the philosophy underlying individualism. C. To examine the trend of young people living alone. D. To stress the rebuilding of personal relationships. Passage Two American dramas and sitcoms would have been candidates for prime time several years ago. But those programs －though some remain popular －increasingly occupy fringe times slots on foreign networks. Instead, a growing number of shows produced by local broadcasters are on the air at the best times. The shift counters longstanding assumptions that TV shows produced in the United States would continue to overshadow locally produced shows from Singapore to Sicily. The changes are coming at a time when the influence of the United States on international affairs has annoyed friends and foes alike, and some people are expressing relief that at least on television American culture is no longer quite the force it once was. “There has always been a concern that the image of the world would be shaped too much by American culture,” said Dr. Jo Groebek, director general of the European Institu te for the Media, a non-profit group. Given the choice, he adds, foreign viewers often prefer homegrown shows that better reflect local tastes, cultures and historical events. Unlike in the United States, commercial broadcasting in most regions of the world －including Asia, Europe, and a lesser extent Latin America, which has a long history of commercial TV －is a relatively recent development. A majority of broadcasters in many countries were either state-owned or state-subsidized for much of the last century. Governments began to relax their control in the 1980’s by privatizing national broadcasters and granting licenses to dozens of new commercial networks. The rise of cable and satellite pay-television increased the spectrum of channels. Relatively inexperienced and often financed on a shoestring, these new commercial stations needed hours of programming fast. The cheapest and easiest way to fill airtime was to buy shows from American studios, and the bidding wars for popular shows were fierce. The big American studios took advantage of that demand by raising prices and forcing foreign broadcasters to buy less popular programs if they wanted access to the best-selling shows and movies. “The studio priced themselves out of prime time,” said Harry Evans Sloan, chairman of SBS Broadcasting, a Pan-European broadcaster. Mr. Sloan estimates that over the last decade, the price of American programs has increased fivefold even as the international ratings for these shows have declined. American broadcasters are still the biggest buyers of American-made television shows, accounting for 90% of the $25 billion in 2001 sales. But international sales which totaled $2.5 billion last year often make the difference between a profit and a loss on show. As the pace of foreign sales slows －the market is now growing at 5% a year, down from the double-digit growth of the 1990’s －studio executives are rethinking production costs. 6. Which of the following best characterizes the image embodied in American shows? A. Self-contradictory B. Prejudice-free C. Culture-loaded D. Audience-targeted 7. The intervention of governments in the 1980’s resulted in __________ . A. the patenting of domination shows and movies B. the emergence of new commercial networks C. the promotion of cable and satellite pay-television D. the intense competition coming from the outside 8. The phrase “on a shoestring” (Para. 6) most probably means __________. A. in need of capital B. after a fashion C. on second thoughts D. in the interests of themselves 9. The main reason why American dramas and sitcoms are driven out of prime time is that ____. A. they lose competitiveness B. they are not market-oriented C. they are too much priced D. they fall short of audience expectations 10. American studio producers will give thought to production costs __________. A. if they have no access to popular shows B. because their endeavors come to no avail C. since bidding wars are no longer fierce D. as international sales pace slows down Passage Three How shops can exploit people's herd mentality to increase sales 1. A TRIP to the supermarket may not seem like an exercise in psychological warfare—but it is. Shopkeepers know that filling a store with the aroma of freshly baked bread makes people feel hungry and persuades them to buy more food than they had intended. Stocking the most expensive products at eye level makes them sell faster than cheaper but less visible competitors. Now researchers are investigating how “swarm intelligence” (th at is，how ants，bees or any social animal，including humans，behave in a crowd) can be used to influence what people buy. 2. At a recent conference on the simulation of adaptive behaviour in Rome，Zeeshan-ul-hassan Usmani，a computer scientist from the Florida Institute of Technology，described a new way to increase impulse buying using this phenomenon. Supermarkets already encourage shoppers to buy things they did not realise they wanted: for instance，by placing everyday items such as milk and eggs at the back of the store，forcing shoppers to walk past other tempting goods to reach them. Mr Usmani and Ronaldo Menezes，also of the Florida Institute of Technology, set out to enhance this tendency to buy more by playing on the herd instinct. The idea is that, if a certain product is seen to be popular, shoppers are likely to choose it too. The challenge is to keep customers informed about what others are buying. 3. Enter smart-cart technology. In Mr Usmani's supermarket every product has a radio frequency identification tag, a sort of barcode that uses radio waves to transmit information，and every trolley has a scanner that reads this information and relays it to a central computer. As a customer walks past a shelf of goods, a screen on the shelf tells him how many people currently in the shop have chosen that particular product. If the number is high, he is more likely to select it too.
江苏省委党校社会学专业在职研究生入学考试英语复习参考资料 一、完形填空（20分） 二、语句翻译（20分） 1、As far as ability is concerned,I am sure he will qualify for the job. 7、Some of the old fantasies about the space age have come true. 14、In general,prices may be brought down by increasing supply or decreasing demand. 17、Jack didn’t know anything about any of the books on the bookshelf,so his choice was quite arbitrary. 18、We are trying to figure out a solution to these urgent problems. 23、The increase in information and knowledge about management will be more important to top manager. 27、Many American students apply for government loans to pay for their education. 32、We came to the meeting full of expectations,yet we left very disappointed. 34、The spokesman made in clear that the president would not cancel the trip under any circumstances. 40、The government has undertaken a series of new environmental initiatives,as a result, many parks and green belts have sprung up all of the country. 43、It is not unusual for this scientist to go to bed at two or three in the morning. 45、We didn’t like his attitude that he deserved special treatment. 48、These artists devoted all their lives to art,and made great contributions to the artistic field. 52、There are a lot of papers to sign,but the only urgent one is this contract. 53、The government is taking these measure in hopes of bringing down the soaring price of houses. 三、阅读理解（30分） 四、段落翻译（30分） 3、在1991年，巴西在全世界环保主义者的压力下改变了做法，它取消了鼓励砍伐亚马逊雨林的税收优惠，批准了一个新雨林保护项目的资金计划。 牛场主、矿工、移民抗议这一行动并继续破坏雨林，尽管速度比以前要慢。去年当矿工为了夺取一群印第安人的土地而将他们杀死使得矛盾扩大了。政府承诺将保护该地区的原住民，问题是这一承诺真实的程度究竟多大。
一.同义词 16.Children may ridicule other children new to a neighborhood. A. make fun of 17.It is useless to attempt to flee from every danger, some risks must be taken. C. run away 18.Many pure metals have little use because they are too soft, rust too easily, or have some other drawbacks. B. disadvantages 19.Magazines are the fifth most important advertising medium, and magazine advertising requires a substantial investment from advertisers. D. considerable 20.Efforts to ameliorate housing conditions for the poor were halted because government funds were cut off. C. improve 21.Because of the close collaboration of architect and builder, the building was completed ahead of schedule. B. joint work 22.After World War , the Vietnamese believed that the French would allow them to be an autonomous people. A. self-governing 23.Physical well-being presupposes that one should vary his diet and often have some wholesome food. C. healthful 24.The layout of the book, with the text on the left and the notes on the right, makes it a pleasure to use. B. arrangement 25.A child leaving home before he is ready is analogous to bird trying to leave the nest before it can fly. D. similar 单选 26.He had always been oblivious to the way Ruth looked, and had never once paid her a compliment. 27.I like the professor's lecture because he amplified his lecture with some vivid slide shows. 28.On the seminar the historians still cannot agree on the date on which the particular war commenced . 29.Despite the news that her son had been dead years ago, she still clung to the hope that he would return some day. 30.During the night a person's temperature may drop one or two degrees, and it can be difficult to arouse him in the morning if his body hasn't become hot yet. 31.The farmers were more anxious for rain than the people in the city because they had more at stake. 32.Man often wonders how the earth evolved from a hot, violent birth to the celebrated watery planet that stands out in pictures from space. 33.When business is depressed , there is usually an obvious increase in unemployment. 34.Social structure organization is simply the way that people, groups, and institutions are organized with respect. to one another. 35.One of the reasons for his popularity in our village is that he asks after almost everyone every time when he comes back from the big city. 二.同义词 16.The winner was deprived of his gold medal because he was found to have taken stimulants before the race. C. was deprived of 17.The army launched a major assault against the rebel army and many citizens joined the army. A. attack 18.Because Charles had forgotten his key, he was locked out. B. unable to in 19.His behavior had been perturbing me more than had cared to admit. D. troubling 20.Lighting levels are carefully controlled to fall within an acceptable level for optimal reading convenience. A. ideal 21It is said that you can intimidate your enemies by speaking in a low voice and carrying a big stick. C. frighten 22 .If you know in advance that the examination is going to be easy, you have no incentive to study very much. D. motive 23.The soldier discovers martial stirrings in his breast as he puts on his uniform. B. excitement 24.Many pure metals have little use because they are too soft, rust too easily, or have some other drawbacks. C. disadvantages 25.You'll succeed in the final examination if you stick to your belief that you are not a failure. A. adhere to 单选 26Care should be taken to decrease the length of time that one is subjected to loud continuous noise. 27.The teacher set up those obstacles for no other purpose than to challenge the students to overcome them. 28.The police who was lack of experiences was completely, taken in by the thief's disguise. 29.My aunt wound a brightly-colored thread round her finger so as not to forget her appointment. 30.They could not go to the theater together because his free time never coincides with hers. 31.A (n) personnel manager has a variety of role relations with people occupying related statuses. 32.This is a difficult job that needs to be tackled whole-heartedly-not ply at. 33.The curtain had risen hardly when shot startled the audience. 34.He would go to endless trouble to help anyone he thought worthy of encouragement. 35.Some professors prefer to control discussion while others prefer to guide the class without dominating it. 三.同义词 16. If you know in advance that the examination is going to be easy, you have no incentive to study very much. B. motive 17.The mother soothed the disappointed child and then promised to take him on a picnic as soon as it stopped raining. D. comforted 18.It is not easy to remain tranquil when events suddenly change your life. C. calm 19.Sales are an accurate gauge of a book's popularity rather than a representation of it's real value. A. criterion 20.Because Charles had forgotten his key, he was locked out. D. unable to in 21.The army launched a major assault against the rebel army and many citizens joined the army. B. attack 22.The winner was deprived of his gold medal because he was found to have taken stimulants before the race. A. was deprived of 23.At the international conference on the nuclear weapons several dissenting statements were made. D. opposing 24.The dominant theme is of tranquility and peacefulness. C. major 25.A conservative person opposes change and too many new ideas. A. unprogressive 单选 26.It is very likely that the Martian will also be adapted to underground existence, for conditions are much more equable underground. 27.The medicine scientists discovered that the prime reason for her lung cancer is excessive smoking. 28.The interviewer interpreted the applicant's late arrival as a sign of disorganization, undependability or lack of interest in the job. 29.After about an early age of 13, perceptions have already been formed and ambitions cast. 30.South Africa's black majority got its first real say in governing early last December. 31.Technology has facilitated the sharing of information and the storage and 32.delivery of information, thus making more information available to more people. 32.Jack is the very person who can be entrusted with either money or secret information. 33.He stopped the car so abruptly that he was hit by the car behind him. 34.The black people launched civil movement, struggling for abolition of slavery. 35.After a long journey, the tourists who experienced danger and hardship reached their destination at length.
1 The 7 Habits of Highly Effective People: Powerful Lessons in Personal Change was a groundbreaker when it was first published in 1990, and it continues to be a business bestseller with more than 10 million copies sold. Stephen Covey, an internationally respected leadership authority, realizes that true success encompasses a balance of personal and professional effectiveness, so this book is a manual for performing better in both arenas. His anecdotes are as frequently from family situations as from business challenges. Before you can adopt the seven habits, you ll need to accomplish what Covey calls a "paradigm shift"--a change in perception and interpretation of how the world works. Covey takes you through this change, which affects how you perceive and act regarding productivity, time management, positive thinking, developing your "proactive muscles" (acting with initiative rather than reacting), and much more. This isn t a quick-tips-start-tomorrow kind of book. The concepts are sometimes intricate, and you ll want to study this book, not skim it. When you finish, you ll probably have Post-it notes or hand-written annotations in every chapter, and you ll feel like you ve taken a powerful seminar by Covey 2 Malleahiliiy(可变性)of Intelligence Historically intelligence has been regarded as a fixed trait; some- thing that we are born with based entirely upon our genes.It was believed that intelligence was based entirely upon our genes.However, this viewpoint has recently come under much discussion, with some researchers now believing that intelligence has little genetic basis---if any. Most researchers take an intermediate stance(姿态). Various techniques have been Used to assess the genetic nature of intelligence. Qccasionally identical twins are separated at birth. If the twins are raised apart, then they have experienced different environments, and the only thing they have in common is their identical genetic make-up. Therefore, the correlation between their performances on intelligence tests can be a reasonably accurate estimate of the role of genetics in intelligence. Studies have consistently shown that genetics account for approximately half of the variation in test score. However, estimates of the heritability of intelligence vary among ethnic and racial groups, as well as across single groups. Another issue that has arisen is about the possibility of overall increases in intelligence. New Zealand researcher James Flynn has shown that scores on intelligence tests have been significantly rising throughput the world instead of remaining steady. So far this increase has not been adequately explained, and countless factors