814电力电子技术-电子科技大学2015硕士入学考试真题

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621英语水平测试-电子科技大学2015硕士入学考试真题

电子科技大学2015年攻读硕士学位研究生入学考试试题电子科技大学2016年硕士研究生入学考试初试自命题科目及代码汇总•111单独考试政治理论•241法语(二外)•242德语(二外)•243日语(二外)•244英语(二外仅日语方向) •288单独考试英语•601数学分析•602高等数学•613分子生物学•615日语水平测试•616公共管理综合•621英语水平测试•622心理学综合•623新闻传播理论•625宪法学•688单独考试高等数学•689西方行政史•690中国近现代史•691政治学原理•692数学物理基础•694生物学综合•694生物学综合•695口腔综合•804行政法与行政诉讼法学•805新闻传播实务•806行政管理综合•808金融学基础•809管理学原理•811大学物理•812地理信息系统基础•813电磁场与电磁波•814电力电子技术•815电路分析基础•818固体物理•820计算机专业基础•821经济学基础•824理论力学•825密码学基础与网络安全•830数字图像处理•831通信与信号系统•832微电子器件•834物理化学•835线性代数•836信号与系统和数字电路•839自动控制原理•840物理光学•845英美文学基础知识及运用•846英语语言学基础知识及运用•847日语专业基础知识及应用•852近代物理基础•853细胞生物学•854国际政治学•855辩证唯物主义和历史唯物主义•856测控通信原理•857概率论与数理统计•858信号与系统•859测控通信基础•860软件工程学科基础综合电子科技大学2015年攻读硕士学位研究生入学考试试题考试科目:621英语水平测试注：无机读卡，所有答案必须写在答题纸上，写在试卷或草稿纸上无效。

Part I Reading Comprehension (40 points)Directions: In this part there are 5 passages, each with some questions or incomplete statements. Read them carefully and then choose from the four suggested answers marked A, B, C and D to answer the questions or complete the statements. Please write your answers on the Answer Sheet.Passage 1Oh no, not Anthony Weiner again.The older generation never gets it. Anthony Weiner, a candidate for mayor of New York, admitted this week to having sent more snaps of himself to a digital acquaintance. As any youngster could have told him, the way to find love is to send photos of your face.Consider Will, a 24-year-old up-and-coming film director in California. He meets potential dates via a smartphone app called Tinder. It finds potential matches who are nearby—your phone always knows where you are—and shows him photos from their Facebook profiles. Will can like or reject each photo. If a woman he likes also likes him, both are alerted and can start chatting.Tinder is quick (you can scroll through dozens of photos in minutes) and spares your blushes (you never know if someone rejects you). Will has already had three romantic encounters and hundreds of matches, he says. Justin Mateen, a co-founder of Tinder, says it has made 100m matches since its launch in September, and led to 50 marriage proposals. He adds: “The app has only really been going for nine months. There could be a baby popping out soon.”Americans are dating longer, which creates opportunities for matchmakers. Some are quite direct.Bang with Friends (BWF), another app, allows users to specify which of their Facebook friends they would like to spend the night with. If both parties feel the same way, BWF notifies them. If not, no one is any the wiser. BWF was booted from Apple’s app store, but that hasn’t stopped it from creating 200,000 pairings since its January launch. BWF’s boss, admits he came up with the concept while “a bit tipsy”.Such apps make it easier to find potential partners, but don’t seem to have turned America into a nation of bed-hoppers. Young women claim to have had a median of 3.6 male intimate friends while young men 6.1 female ones. These figures may be inaccurate—men may exaggerate; women may undercount—but they have not changed much in years.Parents fret that staring at screens all day has made youngsters socially inept face-to-face. A第1 页共12 页survey by two dating sites found that 36-38% of Americans aged 21-34 ask for dates by text message. But when they meet, they must still make their moves in person. Witty joking and a well-placed wink still have their uses.1. It can be summarized from the first three paragraphs that _________.A. we used to judge a potential match by his or her appearanceB. one can find love by sending his photos to a digital acquaintanceC. Anthony Weiner is trying to win more votes from digital friendsD. Tinder will probably replace traditional matchmakers worldwide2. The sixth paragraph is focused on _________.A. the huge success that BWF has achievedB. the serious consequence of digital datingC. the evolution of matchmaking in the U.S.D. the future developments of Facebook3. The last paragraph implies that _________.A. excessive use of apps leaves youngsters socially awkwardB. most young people find love through text messagesC. people in love often move their homes before marriageD. verbal or non-verbal language is still used during dates4. Potential matches found by Tinder are probably _________.A. young, single, and nearbyB. poor, married, but lonelyC. illiterate, retired, but divorcedD. far-away, busy, and happyPassage 2The human body contains enormous quantities of energy. In fact, the average adult has as much energy stored in fat as a one-ton battery. That energy fuels our everyday activities, but what if those actions could in turn run the electronic devices we rely on? Today, innovators around the world are banking on our potential to do just that.Movement produces kinetic energy, which can be converted into power. In the past, devices that turned human kinetic energy into electricity, such as hand-cranked radios, computers and flashlights, involved a person’s full participation. But a growing field is tapping into our energy without our even noticing it.Consider, for example, a health club. With every step you take on a treadmill and with every muscle curl, you turn surplus calories into motion that could drive a generator and produce electricity. The energy from one person’s workout may not be much, but 100 people could contribute significantly to a facility’s power needs.That’s the idea behind the Green Microgym in Portland, Oregon, where machines likes tationary bikes harvest energy during workouts. Pedaling turns a generator, producing electricity that helps to power the building. For now, body energy supplies only a small fraction of the gym’s needs, but the amount should increase as more machines are adapted. “By being extremely energy-efficient and combining human power, solar and someday wind, I believe we’ll be able to be net-zero for electricity sometime this year,” says the gym’s owner, Adam Boesel. His bikes, by the way, aren’t the flirts to put pedal power to work. In some parts of the world, cyclists have been powering safety第2 页共12 页lights for years with devices called bicycle dynamos, which use a generator to create alternating current with every turn of the wheels.Dance clubs are also getting in on the action. In the Netherlands, Rotterdam’s new Club WATT has a floor that harnesses the energy created by the dancers’ steps. For now, it’s just enough to power LED lights in the floor, but in the future, more output is expected from newer technology.5. Using human body energy as power supplies _________.A. requires us to be strongB. is a great new ideaC. proves to be difficultD. is increasingly popular6. It can be learned that the Green Microgym _________.A. is using human, solar and wind power to produce electricityB. is the first to use bikes to harvest human body energyC. will be able to satisfy its power needs by using green energyD. will introduce the technology to other parts of the world7. What is the author’s most likely comment on the application of body energy?A. It is unrealistic at present.B. It has a promising future.C. Its effect is still unknown.D. It depends on the energy cost.Passage 3The first of Laurence Smith’s two weddings was meant to take place in the midwinter snow not far south of the Arctic Circle. The second foresaw balmy blue skies in Palm Springs, California. As it turned out, the guests were greeted by rain and slush in the far north, then by a chill and more rain in the Californian desert.If the weather is capable of surprising him, why should anyone trust Mr. Smith’s forecast for 2050? Because the growing freakiness of weather is precisely his point. Climate change is one of four mega-trends, along with globalization, population growth and surging demand for natural resources, that he thinks will shape the world over the coming decades. The first part of his book The New North: The World in 2050 is a familiar tale of teeming cities, roaring trade, harder-to-get-at oil and rising sea levels.But Mr. Smith comes into his own when he explores the consequences of these trends (climate change especially) for the quarter of the Earth that lies at latitudes above 45°N. A geographer at the University of California, Los Angeles, he specializes in the frozen lands of Russia, Canada, Alaska and Iceland. The region is about to undergo a great transformation.The planet’s warming may be global, but climate-change models predict it will be amplified in the north. Permafrost will melt and settlement patterns will change. Inland, construction will become trickier and ice roads less dependable, so development will gravitate to the coasts. By mid-century the Arctic Ocean may be briefly free of sea ice in September, a boon to shipping. Crops will spread north as seal hunters become farmers.Interest in the region’s vast and increasingly accessible natural resources is already growing, along with the potential for conflict over the rights to these riches. Mr. Smith believes there is every chance that the development of the “new north” will be peaceful, thanks to habits of cooperation and第3 页共12 页an internationally accepted rule book for laying down rights to the seabed. He sees a leading role for the region’s indigenous peoples.By 2050 the answers to some very big questions should be clear: what happens to the north’s massive stocks of carbon in the soil as it defrosts; whether great schemes to channel freshwater from north to south are attempted; how populous, resource-hungry China works with Russia’s emptying, resource-rich Far East. Mr. Smith reckons an area about one and a half times the size of the United States will be habitable, albeit for much of the year still cold and dark. The development of the new north, he thinks, might resemble that of the American West, dotted with settlements formed for mining and trade.Obscuring the view of 2050, however, is a caveat that looms as large as an Arctic iceberg. Mr. Smith sets ground rules that allow him to extrapolate into the future without worrying about disruptions such as game-changing leaps in technology. This is an “informed thought-experiment”rather than a proper prediction. But for anyone curious about the new north—let alone thinking of investing in Arctic derivatives—it is an instructive exercise.8. The word “boon” in the fourth paragraph can be replaced by _________.A. prohibitionB. prosperityC. benefitD. catastrophe9. According to Laurence Smith, the following are all very likely to happen in the future decadesEXCEPT _________.A. The local people in the “new north” will benefit from the climate changeB. The development of the “new north” will be on a peaceful processC. The natural resources in the “new north” will be able to exploitedD. The large amounts of carbon in the “new north” soils will be safely controlled10. What can be inferred from the passage?A. The author takes a skeptical attitude towards Laurence Smith’s predictions of the Arctic.B. The author reckons Laurence Smith is somewhat optimistic in imagining the “new north”C. Laurence Smith did a lot of experiments in combining geographical predictions andeconomic development.D. Laurence Smith shares with the author that the future of the Article depends on ourawareness and actions.11. Which of the following titles is more appropriate for the passage?A. The Arctic: The de-icing ageB. Climate Change: Humankind’s futureC. A Day Dreamer: Laurence Smith’s new writing styleD. 2050: The end of the worldPassage 4The newspaper must provide for the reader the facts, unalloyed, unslanted, objectively selected facts. But in these days of complex news it must provide more; it must supply interpretation, the meaning of the facts. This is the most important assignment confronting American journalism—to make clear to the reader the problems of the day, to make international news as understandable as第4 页共12 页community news, to recognize that there is no longer any such thing (with the possible exception of such scribbling as society and club news) as “local”news, because any event in the international area has a local reaction in manpower draft, in economic strain, in terms, indeed, of our very way of life.There is in journalism a widespread view that when you embark on interpretation, you are entering choppy and dangerous waters, the swirling tides of opinion. This is nonsense.The opponents of interpretation insist that the writer and the editor shall confine himself to the “facts”. This insistence raises two questions: What are the facts? And: Are the bare facts enough?As to the first query. Consider how a so-called “factual” story cones about. The reporter collects, say, fifty facts; out of these fifty, his space allotment being necessarily restricted, he selects the ten, which he considers most important. This is Judgment Number One. Then he or his editor decides which of these ten facts shall constitute the lead of the piece. This is important decision because many readers do not proceed beyond the first paragraph. This is Judgment Number Two. Then the night editor determines whether the article shall be presented on page one, where it has a large impact, or on page twenty-four, where it has little. Judgment Number Three.Thus, in the presentation of a so-called “factual” or “objective” story, at least three judgments are involved. And they are judgments not at all unlike those involved in interpretation, in which reporter and editor, calling upon their general background, and their “news neutralism,” arrive at a conclusion as to the significance of the news.The two areas of judgment, presentation of the news and its interpretation, are both objective rather then subjective processes—as objective, that is, as any human being can be. (Note in passing: even though complete objectivity can never be achieved, nevertheless the ideal must always be the beacon on the murky news channels.) Of an editor is intent on slanting the news, he can do it in other ways and more effectively than by interpretation. He can do it by the selection of those facts that prop up his particular plea. Or he can do it by the pay he gives a story—promoting it to page one or demoting it to page thirty.12. The title that best expresses the ideas of this passage is _________.A. Interpreting the News.B. Choosing Facts.C. Subjective versus Objective Processes.D. Everything Counts.13. Why does the writer of an article select ten out of fifty available facts?A. His editor is prejudiced.B. Space is limited.C. The subject is not important.D. The newspaper is arbitrary.14. What is the least effective way of “slanting” news?A. Placement.B. Concentration.C. InterpretationD. His editor is prejudiced.15. Why should the lead sentence present the most important fact?A. It will influence the reader to continue.B. It will be the best way to write.C. Some readers do not read beyond the first paragraph.D. It will gratify the editor.第5 页共12 页Passage 5One of the most pivotal moments in American literature occurred near the end of the nineteenth century as authors such as a young man named Stephen Crane began to embrace a literary style forged in Europe a bit earlier and which would come to be known as naturalism. Crane was born to parents in the ministry and grew up in a household grounded in religious beliefs and context. Yet, before long, Crane had, for the most part, rejected religion and the idea of divine intervention in favor of a more hands-on approach to the world. As he began to develop as a writer, naturalist themes of man versus nature, the unrelenting power of nature, and an objective view of the world began to dominate his writing. Naturalists attempted to depict the most accurate view of life unadulterated and unobstructed by external commentary or spiritual intervention. Ultimately Crane’s masterful short story The Open Boat stands as one of the most complete and developed works of the naturalist genre.The first apparent element of naturalism in The Open Boat is its subject matter—a shipwreck. Being as true to life as possible is one of the most common goals of a naturalistic writer, and, in this short story, Crane is no exception. It did not come from Crane’s imagination. Rather, it stemmed from his personal experience. As a young war reporter, Crane was on his way from Florida to Cuba when his vesse1, the Commodore, encountered a violent tempest. Within hours, the ship had sunk, leaving a few lucky survivors on a tiny lifeboat to be subjected to the full of nature. Throughout the story Crane depicts scene after scene as if they were snapshots or a shorn film of what the men in the boat were up against. Through his prose, Crane is able to reveal the unadulterated brutal realism manifest in nature itself.As Crane continues with the theme of man versus nature in The Open Boat, the element of pessimism crucial to any naturalistic work, becomes quite apparent. The men are at the mercy of the storms and the seas and cannot do much to save themselves. In this sense, Crane reveals the indifference of nature and the universe in relation to the life or plight of human beings in general. It’s obvious to him that angels will not swoop down and save the unfortunate men. The situation of the shipwreck is ideal because ordinary, everyday people must face an extreme situation from which it is more than likely that they will perish. Crane continually creates a mood of impending doom and the punishing nature of the universe throughout the story. Along the way, he provides little commentary on the situation, forcing readers to place themselves immediately on the boat with the men while enforcing the dark tone of the story. But, even to Crane and most naturalist writers, all is not lost.While Crane’s work The Open Boat is a dark account of a chance situation that turns fatal for many, but not all, of the crew of the Commodore, it also sets forth the main elements of a naturalistic literary work at the turn of the twentieth century. Despite the fact that nature can be unrelenting and compassionless towards humans at any given moment, Crane ultimately shows how individuals still always have the capacity to strive together to overcome hardships and disaster. Furthermore, the accuracy and detail by Crane shun any possibility of a sugarcoated reality and reveals the true ferocity of nature as it is.16. Which of the following can be inferred from the first paragraph about Stephen Crane?第6 页共12 页A. He enjoyed the ministry and listening to preachers.B. He did not enjoy writing when he was young.C. He was rivaled by no other author of his time.D. He was not in tune with the beliefs of his parents.17. Which of the sentences below best expresses the essential information in the underlinedsentence in the first paragraph?A. Naturalists liked to place their own opinions on spirituality in their writing.B. Naturalists placed more emphasis on representing life as it appeared to them.C. Naturalists tried to embody the most precise view of life by looking to religion.D. Naturalists believed the life was obstructed by outside ambition and spirituality.18. According to the second paragraph, The Open Boat is important as a naturalist work because_________.A. it is true account taken from Crane’s own personal experienceB. the story is completely fabricated from Crane’s imaginationC. it is based on a series of events in a shipwreck that Crane heard ofD. it does not attempt to glorify Crane’s heroism against nature19. The author discusses nature in the third paragraph in order to _________.A. show how Crane believes divine power will save humanityB. note that nature itself is stronger than all of humankindC. indicate that nature does not care for strife among peopleD. reveal how it is pessimistic toward life on Earth20. According to the fourth paragraph, the men in the boat are significant because _________.A. they show that by banding together, human beings can surviveB. they represent the ultimate downfall of life according to CraneC. they allow fate to run its course and decide their own futureD. they discount nature and do not take it seriously until the endPart II Structure and Vocabulary (20 points)Directions: Beneath each of the following sentences, there are four choices marked A, B, C and D. Choose the one that best completes the sentence. Please write your answers on the Answer Sheet.21. The general manager usually _________ a question before he gives his answer.A. pondersB. extractsC. imploresD. enlists22. His classmates dislike him for his _________ as he always boasts about his family.A. reclusionB. pomposityC. prideD. austerity23. The writer told several _________ about his colleagues and made everybody laugh.A. legendsB. mythsC. fablesD. anecdotes24. She must have been pretty _____ to fall for such an old trick.A. interestedB. gullibleC. enthusiasticD. shrewd25. This is the ______ piano on which the composer created some of his greatest works.A. trueB. originalC. realD. genuine第7 页共12 页26. A lack of appetite may be ________ of a major mental or physical disorder.A. inquisitiveB. initiativeC. indicativeD. informative27. The self-image controls a person’s attitudes or _________ of what happens to her.A. interpretationsB. approachesC. commitmentsD. simulations28. By the year 2040, Yale University will need over eight acres of land to _________ its library.A. manipulateB. accommodateC. illuminateD. obligate29. If you don’t know where you’ re going in life, you are _________ to wind up somewhere else.A. possibleB. inevitableC. optionalD. liable30. As far as marriage is concerned, it is mutual care and love that _________.A. mountsB. discountsC. countsD. calculates31. If the ten amendments that _________ the Bill of Rights of the US Constitution were a familyof ten children, you wouldn’t want to be the Third.A. includeB. embraceC. compriseD. involve32. The person in custody must, prior to interrogation, be clearly informed that he has the right toremain _________.A. silentB. taciturnC. speechlessD. consent33. The road wound rather _________ into a valley, in which the Pemberley House was situated.A. unprecedentedlyB. abruptlyC. promptlyD. irreversibly34. There is some reason for not giving up my career and _________ a different one.A. taking inB. bringing aboutC. arising fromD. embarking on35. Their house was in close _________ to ours, so we became intimate friends in time.A. vicinityB. contactC. relationD. community36. What all this _________ rhetoric obscured was the lack of hard evidence that violent mediaactually turns children into killers.A. multiculturalB. innovativeC. hyperbolicD. interactive37. A(n) _________ reading approach to reading is a combination of approaches—global, analyticand synthetic—used to suit the convenience of the reader.A. literalB. innovativeC. liberalD. eclectic38. _________ with languages gives you an edge in many jobs and professional opportunities, butis especially valuable in fields such as advertising, business, education and foreign affairs.A. ThresholdB. FacilityC. SpecializationD. Accommodation39. Rather than dictate how I think it ought to work, I would tell my employees to _________something that will work.A. get back toB. get out ofC. come along withD. come up with40. The visitors were impressed by the facilities planned and programmed ________ theirinterrelationships.A. in terms ofB. in aspects ofC. in units ofD. in case ofPart III Cloze (20 points)Directions: Fill in each blank with ONE appropriate word to complete the passage. Please write your answers on the Answer Sheet.第8 页共12 页Passage A:A new report published on November 4th takes a different approach.GlobalWebIndex (GWI), a market-research firm 41 local partners in 32 countries, surveys 170,000 consumers a year and recently began to ask detailed questions about internet use. It 42 China and India in the top three for Facebook users. SimilarWeb, 43 does IP-based analysis, does not even put China in the top ten.One reason for the 44 is that in many developing markets devices are widely shared. Conversely, more than three-quarters of respondents in the GWI report said they used more than one 45 . 46 factor is the spread of virtual private networks (VPNs) and proxy servers, which 47 it possible to surf the web through a foreign server.Once restricted to the tech-literate, these are now common and easy to use. Chinese citizens who want to vault the Great Firewall to use Facebook can do so with a couple of clicks. Foreign fans of the BBC can use the 48 trick to watch its programs via iPlayer, supposedly barred 49 Britain. Since VPNs and proxy servers are clustered in 50 with favorable rules, such as Sweden and the Netherlands, any count of visits to such sites will be skewed. 41. ____________42. ____________43. ____________44. ____________45. ____________46. ____________47. ____________48. ____________49. ____________50. ____________Passage B:Happy hours are not necessarily happy, 51 do they last for an hour, but they have become a part of the ritual of the office worker and businessman.52 weekdays in pubs and bars throughout America, there is the late afternoon happy hour. The time may 53 from place to place, but usually it is held from four to seven. 54 the workday is finished, office workers in large cities and small towns take a relaxing pause and do not go directly home. They head off 55 for the nearest bar or pub to be with friends, co-workers and colleagues. Within minutes the pub is filled to capacity 56 businessmen and secretaries, office clerks and stock executives. They gather 57 the bar like birds around a fountain or forest animals around a watering hole and chat about the trifles of office life or matters more personal. This is their desert garden, the place to relieve the day’s stress at the office.At these happy hours, social binding occurs 58 people who share the same workplace or similar professions. They may chat about each other or talk about a planned project that has 59 to meet a deadline. In this 60 , these places become extensions of the workplace and constitute a good portion of one’s social life. 51. ____________52. ____________53. ____________54. ____________55. ____________56. ____________57. ____________58. ____________59. ____________60. ____________第9 页共12 页Part IV Paraphrasing (20 points)Directions: Paraphrase the underlined parts. Please write your answers on the Answer Sheet.Consult any encyclopedia and you will find Charles Babbage credited with having conceived the first automatic digital computer. (61) Dig deeper, however, and it quickly becomes apparent that Babbage had a lot of help.Others before him had already tried to build calculating contraptions, notably Gottfried Leibniz, a German mathematician. (62) Babbage held regular salons and founded clubs where his ideas were sharpened. And there was also Ada Lovelace, his collaborator and the world’s first computer programmer.The argument against the great man theory of invention is not new. (63) But the main merit of Walter Isaacson’s new book The Innovators is to show that this is particularly true in information technology—despite the customary lionization of many of its pioneers, from Babbage and Alan Turing to Bill Gates and Linus Torvalds.All appear in Mr. Isaacson’s book, which explains its length. Whether their worlds revolved around the computer itself, the microchip, software, the PC, the internet or everything in between—these are all stories that show that invention always has many fathers (and mothers). (64) In fact, those who tried to go it alone tended to fail.(65) Mr. Isaacson thinks geniuses are important but they have to be seen in the context of times they lived in and the people they collaborated with. John von Neumann was a Hungarian-born polymath who worked on the ENIAC, one of the first programmable machines. His name is associated by many with early advances in programming and software architecture. (66) But it was a group of women who were at the forefront of programming, because back then it often involved plugging in wires and throwing switches. “If the ENIAC’s administrators had known how crucial programming would be…they might have been more hesitant to give such an important role to women,” he quotes one of them, Jean Jennings, as saying.(67) The ENIAC also shines a light on another issue: how innovation should best be commercialized. In 1945 von Neumann published a paper summarizing the project’s ideas—making it impossible for others on the team to patent them. The debate over whether innovation is better served by sharing intellectual property or by protecting it has been heated.(68) Mr. Isaacson clearly thinks that innovation is all about getting the mix right, though he doesn’t put it quite that way. If a brilliant leader is too self-involved, as was the case with William Shockley, an American physicist who helped invent the transistor radio, things fall apart. (69) Similarly, teams that lack a willful visionary often falter, as happened after Steve Jobs left Apple. Groups with a wide variety of specialities and experiences do much better than a bunch of left-brainers.The Innovators has not quite lived up to its own advice of getting the mix right. (70) Mr. Isaacson could have dedicated more pages to what he calls “lessons from the journey”, rather than retelling at length stories that other books have already laid out, even if he does give them credit. Then again, just like great technology, a good book doesn’t just emerge from nowhere.第10 页共12 页。

电子科技大学2015年硕士研究生金融学综合考研真题_电子科技大学专业课真题

电子科技大学2015年攻读硕士学位研究生入学考试试题考试科目：431 金融学综合注：所有答案必须写在答题纸上，写在试卷或草稿纸上均无效。

一、判断题，正确的标注“ü”，错误的标注“û”。

（每题 1 分，共 10 分）1、通常而言，未对信用贷款申请者进行信用记录审核的银行更加可能吸引到低质量的高风险客户，这反映了信贷过程中的“逆向选择（Adverse Selection）”问题。

（）2、某投资者声称“根本无法通过分析股票的历史信息而获得异常回报”，这说明该投资者是“弱式有效市场”的坚信者。

（）3、平均而言，创业板较之主板具有较高市盈率（Price-to-Earning Ratio, 简称PE Ratio）的原因在于，创业板市场的投资者更加非理性，从而导致高的市盈率。

（）4、套期保值者和投机者是金融市场上基本的两类投资者，而投机者的本质就是赌徒。

（）5、远期和期货属于风险对冲的工具，而期权和互换属于保险的工具。

（）6、根据组合选择理论，市场上存在无风险资产的情形下，不同投资者最优的风险资产组合并不依赖于其个人的风险偏好。

（）7、假设你当前建立3个月后到期的、5000蒲式耳的小麦期货空头，并缴纳$2,000的保证金。

第二天，该期货价格下跌5美分，那么你保证金账户的资金余额将为$2,000 + $250 =$2,250。

（）8、2014年5月29日，Apple公司股票的收盘价为每股$921/16。

假设现有以Apple公司股票为标的资产、执行价格为每股$120、到期日为2014年12月25日的看涨期权，那么，可以判断该看涨期权价格为零。

9、其它条件不变的情况下，标的资产的价格波动越大，看涨期权和看跌期权的价格都越高。

（）10、有限责任公司的股东相当于持有以公司资产为标的资产、到期债务总额为执行价格、债务到期日为到期日的一份看涨期权，债权人则相当于持有一份看跌期权。

（）二、单项选择（每题 3 分，共 45分）第 1 页共7 页第 2 页共 7 页1、每份美国国债的面值高达$100,000，现有一位投资者拟将手头的$1,000投资于美国国债。

813电磁场与电磁波-电子科技大学2015硕士入学考试真题

电子科技大学2015年攻读硕士学位研究生入学考试试题电子科技大学2016年硕士研究生入学考试初试自命题科目及代码汇总•111单独考试政治理论•241法语(二外)•242德语(二外)•243日语(二外)•244英语(二外仅日语方向) •288单独考试英语•601数学分析•602高等数学•613分子生物学•615日语水平测试•616公共管理综合•621英语水平测试•622心理学综合•623新闻传播理论•625宪法学•688单独考试高等数学•689西方行政史•690中国近现代史•691政治学原理•692数学物理基础•694生物学综合•694生物学综合•695口腔综合•804行政法与行政诉讼法学•805新闻传播实务•806行政管理综合•808金融学基础•809管理学原理•811大学物理•812地理信息系统基础•813电磁场与电磁波•814电力电子技术•815电路分析基础•818固体物理•820计算机专业基础•821经济学基础•824理论力学•825密码学基础与网络安全•830数字图像处理•831通信与信号系统•832微电子器件•834物理化学•835线性代数•836信号与系统和数字电路•839自动控制原理•840物理光学•845英美文学基础知识及运用•846英语语言学基础知识及运用•847日语专业基础知识及应用•852近代物理基础•853细胞生物学•854国际政治学•855辩证唯物主义和历史唯物主义•856测控通信原理•857概率论与数理统计•858信号与系统•859测控通信基础•860软件工程学科基础综合“电磁场与电磁波”试题共 3 页第 1 页电子科技大学2015年攻读硕士学位研究生入学考试试题考试科目：813 电磁场与电磁波注：所有答案必须写在答题纸上，做在试卷或草稿纸上无效。

一、填空题（每空2分，共30分）1. 在介电常数02.5e e =的电介质中，已知电场强度23V/m x y z E e x e y e z =++r r r r，则介质中的自由电荷体密度为r = 3C /m 、极化（束缚）电荷体密度为p r = 3C /m 。

电力电子技术(本科)电子科技大学含答案

电子科技大学网络教育考卷（A1卷）(20 年至20 学年度第学期)考试时间年月日(120分钟) 课程电力电子技术教师签名_____大题号一二三四五六七八九十合计得分一、填空题(每小题1分，共30分)1、请在空格内标出下面元件的简称：电力晶体管；可关断晶闸管；功率场效应晶体管；绝缘栅双极型晶体管；IGBT 是和的复合管。

2、晶闸管对触发脉冲的要求是、和。

3、多个晶闸管相并联时必须考虑的问题，解决的方法是。

4、在电流型逆变器中，输出电压波形为波，输出电流波形为波。

5、型号为KS100-8的元件表示晶闸管、它的额定电压为伏、额定有效电流为安。

6、180°导电型三相桥式逆变电路，晶闸管换相是在_ 上的上、下二个元件之间进行；而120º导电型三相桥式逆变电路，晶闸管换相是在_ 上的元件之间进行的。

7、当温度降低时，晶闸管的触发电流会、正反向漏电流会；当温度升高时，晶闸管的触发电流会、正反向漏电流会。

8、按逆变后能量馈送去向不同来分类，电力电子元件构成的逆变器可分为逆变器与逆变器两大类。

9、常用的过电流保护措施有、、、。

（写出四种即可）10、由晶闸管构成的逆变器换流方式有换流和换流。

11、一个单相全控桥式整流电路，交流电压有效值为220V ，流过晶闸管的电流有效值为15A ，则这个电路中晶闸管的额定电压可选为；晶闸管的额定电流可选为。

二、单项选择题(每小题1.5分，共15分。

从每小题的四个备选选答案，选出一个正确答案，并将正确答案的号码填在题干后面的括号内。

)1、单相半控桥整流电路的两只晶闸管的触发脉冲依次应相差度。

A 、180°，B 、60°， c 、360°， D 、120°2、α为度时，三相半波可控整流电路，电阻性负载输出的电压波形，处于连续和断续的临界状态。

2015电子科技大学研究生试卷答案

1一．填空题(每空3分，共15分)1.不同构的3阶简单图的个数为__4___。

2．图1中的最小生成树的权值为__20____。

3.基于图2的最优欧拉环游的总权值为____37___。

4.图3中块的个数为___4____。

5.图4中强连通分支的个数为____3____。

二．单项选择(每题3分，共15分)1．关于图的度序列，下列命题错误的是( D ) (A) 同构的两个图的度序列相同；(B) 非负整数序列12(,,,)n d d d 是图的度序列当且仅当1ni i d =∑是偶数；(C) 如果非负整数序列12(,,,)n d d d (2)n ≥是一棵树的度序列，那么序列6 图1图2图3图42中至少有两个整数的值为1；(D). 如果非负整数序列12(,,,)n d d d 是简单图的度序列，那么在同构意义下只能确定一个图。

2．关于n 阶简单图的邻接矩阵()ij n n A a ⨯=，下列说法错误的是（ C ） (A) 矩阵A 的行和等于该行对应顶点的度数； (B) 矩阵所有元素之和等于该图边数的2倍；(C) 不同构的两个图，它们的邻接矩阵特征谱一定不同； (D) 非连通图的邻接矩阵一定可以表示为准对角矩阵形式。

3.关于欧拉图，下面说法正确的是( B ) (A) 欧拉图存在唯一的欧拉环游； (B) 非平凡欧拉图中一定有圈； (C) 欧拉图中一定没有割点； (D) 度数为偶数的图一定是欧拉图。

4.关于哈密尔顿图，下列命题错误的是( B )(A)设G 是3n ≥的简单图，若其闭包是完全图，则G 是哈密尔顿图； (B) 若n 阶单图的闭包不是完全图，则它一定是非哈密尔顿图； (C)若G 是哈密尔顿图，则对于V 的每个非空顶点子集S ，均有()G S S ω-≤；(D) 若G 是3n ≥的非H 单图，则G 度弱于某个,m n C 图。

5.关于偶图，下列说法错误的是( B ) (A) 偶图中不存在奇圈；(B) 非平凡偶图的最大匹配是唯一的；(C) (0)k k 正则偶图存在完美匹配；(D) 偶图中，最大匹配包含的边数等于最小点覆盖包含的顶点数。

电子科技大学【2015 年攻读硕士学位研究生入学考试试题】241专业课真题

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电力电子技术试题20套及答案

考试试卷( 1 )卷一、填空题（本题共8小题，每空1分，共20分）1、电子技术包括______________和电力电子技术两大分支，通常所说的模拟电子技术和数字电子技术就属于前者。

2、为减少自身损耗，提高效率，电力电子器件一般都工作在_________状态。

当器件的工作频率较高时，_________损耗会成为主要的损耗。

3、在PWM控制电路中，载波频率与调制信号频率之比称为_____________，当它为常数时的调制方式称为_________调制。

在逆变电路的输出频率范围划分成若干频段，每个频段内载波频率与调制信号频率之比为桓定的调制方式称为___分段同步_________调制。

4、面积等效原理指的是，___冲量______相等而__形状_____不同的窄脉冲加在具有惯性的环节上时，其效果基本相同。

5、在GTR、GTO、IGBT与MOSFET中，开关速度最快的是__MOSFET_，单管输出功率最大的是__GTO_，应用最为广泛的是__IGBT___。

6、设三相电源的相电压为U2，三相半波可控整流电路接电阻负载时，晶闸管可能承受的最大反向电压为电源线电压的峰值，即，其承受的最大正向电压为。

7、逆变电路的负载如果接到电源，则称为逆变，如果接到负载，则称为逆变。

8、如下图，指出单相半桥电压型逆变电路工作过程中各时间段电流流经的通路(用V1,VD1,V2,VD2表示)。

(1) 0~t1时间段内，电流的通路为___VD1_____；(2) t1~t2时间段内，电流的通路为___V1____；(3) t2~t3时间段内，电流的通路为__VD2_____；(4) t3~t4时间段内，电流的通路为__V2_____；(5) t4~t5时间段内，电流的通路为___VD1____；页脚内容84页脚内容84页脚内容84二、选择题（本题共10小题，前4题每题2分，其余每题1分，共14分）1、单相桥式PWM 逆变电路如下图，单极性调制工作时，在电压的正半周是（ B ） A 、V1与V4导通，V2与V3关断B 、V1常通，V2常断，V3与V4交替通断C 、V1与V4关断，V2与V3导通D 、V1常断，V2常通，V3与V4交替通断2、对于单相交流调压电路，下面说法错误的是（ C ）A 、晶闸管的触发角大于电路的功率因素角时，晶闸管的导通角小于180度B 、晶闸管的触发角小于电路的功率因素角时，必须加宽脉冲或脉冲列触发，电路才能正常工作C 、晶闸管的触发角小于电路的功率因素角正常工作并达到稳态时，晶闸管的导通角为180度D 、晶闸管的触发角等于电路的功率因素角时，晶闸管的导通角不为180度3、在三相三线交流调压电路中，输出电压的波形如下图所示，在t1~t2时间段内，有（）晶闸管导通。

840物理光学-电子科技大学2015硕士入学考试真题

电子科技大学2015年攻读硕士学位研究生入学考试试题电子科技大学2016年硕士研究生入学考试初试自命题科目及代码汇总•111单独考试政治理论•241法语(二外)•242德语(二外)•243日语(二外)•244英语(二外仅日语方向) •288单独考试英语•601数学分析•602高等数学•613分子生物学•615日语水平测试•616公共管理综合•621英语水平测试•622心理学综合•623新闻传播理论•625宪法学•688单独考试高等数学•689西方行政史•690中国近现代史•691政治学原理•692数学物理基础•694生物学综合•694生物学综合•695口腔综合•804行政法与行政诉讼法学•805新闻传播实务•806行政管理综合•808金融学基础•809管理学原理•811大学物理•812地理信息系统基础•813电磁场与电磁波•814电力电子技术•815电路分析基础•818固体物理•820计算机专业基础•821经济学基础•824理论力学•825密码学基础与网络安全•830数字图像处理•831通信与信号系统•832微电子器件•834物理化学•835线性代数•836信号与系统和数字电路•839自动控制原理•840物理光学•845英美文学基础知识及运用•846英语语言学基础知识及运用•847日语专业基础知识及应用•852近代物理基础•853细胞生物学•854国际政治学•855辩证唯物主义和历史唯物主义•856测控通信原理•857概率论与数理统计•858信号与系统•859测控通信基础•860软件工程学科基础综合电子科技大学2015年攻读硕士学位研究生入学考试试题考试科目：840 物理光学注：所有答案必须写在答题纸上，写在试卷或草稿纸上均无效。

一、选择题（每小题3分、共60分）1.可以用复振幅表示光波的条件是。

A. 线性运算B. 非线性运算C. 单色光D. 复色光2. 部分偏振光可以表示为。

A. 两正交线偏振光的叠加B. 线偏振光和圆偏振光的叠加C. 线偏振光和自然光的叠加D. 线偏振光和椭圆偏振光的叠加3. 自然光正入射到界面，其反射光为。

电子科技大学2015年硕士研究生微电子器件考研真题_电子科技大学专业课真题

电子科技大学2015年攻读硕士学位研究生入学考试试题考试科目：832 微电子器件注：所有答案必须写在答题纸上，写在试卷或草稿纸上均无效。

一、填空题（共45分，每空1分）1、泊松方程的积分形式即是（）定理，它的物理意义是：流出一个闭合曲面的电通量等于该闭合曲面围成的体积内的（）。

2、PN结的扩散电容和势垒电容有很多不同之处。

例如：（）只存在于正向偏压之下；（）的正负电荷在空间上是分离的；（）能用作变容二极管。

3、锗二极管和相同掺杂浓度、相同尺寸的硅二极管相比，其反向饱和电流更（），正向导通压降更（）。

4、碰撞电离率是指每个载流子在（）内由于碰撞电离产生的（）的数目。

电场越（），材料的禁带宽度越（），碰撞电离率将越大。

5、温度升高时，PN结的雪崩击穿电压将（），这是因为温度升高将导致晶格振动加强，因而载流子的平均自由程（）。

6、MOSFET用于数字电路时，其工作点设置在（）区和（）区；双极型晶体管用于模拟电路时，其直流偏置点设置在（）区。

7、双极型晶体管的t b既是基区渡越时间，又是（）电阻与（）电容的乘积。

8、双极型晶体管的跨导代表其（）电流受（）电压变化的影响。

双极型晶体管的直流偏置点电流I E越大，跨导越（）；工作温度越高，跨导越（）。

（第三、四个空填“大”或“小”）9、一般来说，双极型晶体管的几个反向电流之间的大小关系为：I ES（）I CS；I CBO（）I CEO；BV CBO（）BV CEO；BV EBO（）BV CBO（填“>”、“<”或“=”）10、当双极型晶体管集电极反偏，发射极开路时，发射极电流（）零，发射结上的偏压（）零。

（填“>”、“<”或“=”）11、增加双极型晶体管的基区宽度将（）厄尔利电压，（）基极电阻，（）基区输运系数。

12、NMOS的衬底相对于源端应该接（）电位。

当|V BS|增加时，其阈值电压将（）。

（第二个空填“增大”、“减小”或“不变”）13、MOSFET的沟道载流子和位于半导体内的载流子相比，除受到（）散射及电离杂质散射作用外，还会受到（）散射，因此，通常沟道载流子的迁移率（）体内载流子迁移率。

809管理学原理-电子科技大学2015硕士入学考试真题

电子科技大学2015年攻读硕士学位研究生入学考试试题电子科技大学2016年硕士研究生入学考试初试自命题科目及代码汇总•111单独考试政治理论•241法语(二外)•242德语(二外)•243日语(二外)•244英语(二外仅日语方向) •288单独考试英语•601数学分析•602高等数学•613分子生物学•615日语水平测试•616公共管理综合•621英语水平测试•622心理学综合•623新闻传播理论•625宪法学•688单独考试高等数学•689西方行政史•690中国近现代史•691政治学原理•692数学物理基础•694生物学综合•694生物学综合•695口腔综合•804行政法与行政诉讼法学•805新闻传播实务•806行政管理综合•808金融学基础•809管理学原理•811大学物理•812地理信息系统基础•813电磁场与电磁波•814电力电子技术•815电路分析基础•818固体物理•820计算机专业基础•821经济学基础•824理论力学•825密码学基础与网络安全•830数字图像处理•831通信与信号系统•832微电子器件•834物理化学•835线性代数•836信号与系统和数字电路•839自动控制原理•840物理光学•845英美文学基础知识及运用•846英语语言学基础知识及运用•847日语专业基础知识及应用•852近代物理基础•853细胞生物学•854国际政治学•855辩证唯物主义和历史唯物主义•856测控通信原理•857概率论与数理统计•858信号与系统•859测控通信基础•860软件工程学科基础综合电子科技大学2015年硕士学位研究生入学考试试题考试科目：809管理学原理注：所有答案必须写在答题纸上，写在试卷或草稿纸上均无效。

一、名词解释（每小题3分，共15分）1.法约尔桥2.权力差距3.职能职权4.保健因素5.德尔菲法二、判断题（每小题1分，共15分。

在正确说法后面写T，在不正确说法后面写F）1.管理主要的目的是使资源成本最小化，因此，追求效率是管理的目标之一。

2015年电子科技大学研究生入学考试《英语翻译基础》真题及答案

2015年电子科技大学研究生入学考试《英语翻译基础》真题(总分：100.00，做题时间：90分钟)一、词语翻译1.英译汉_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________2.VR_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：((Virtual Reality)虚拟现实)3.conditions-based withdrawal_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(有条件撤军)4.UESTC_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：((University of Electronic Science and Technology in China)中国电子科大学)5.ATM_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：((Automatic Teller Machine)自动取款机)6.dynamic equivalence_________________________________________________________________________________ _____________________________________________________________________________________正确答案：(动态对等)7.magic realism literature_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(魔幻现实主义文学)8.foreign capital flow_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(外资流动)9.carbon emission reduction goal_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(碳减排目标)10.International Monetary Foundation_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(国际货币基金会)11.Wuthering Heights_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(《呼啸山庄》)12.most-favored nation treatment______________________________________________________________________________________________________________________________________________________________________正确答案：(最惠国待遇)13.Society Security Number_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(美国社会安全号)14.GDP_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：((Gross Domestic Product)国内生产总值)15.GRE_________________________________________________________________________________ _________正确答案：((Graduate Record Examination)美国研究生入学考试)16.WAN_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：((Wide Area Network)广域网)17.汉译英_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________18.工商管理硕士_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(MBA(Master of Business Administration))19.雅思_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(IELTS(International English Language Testing System))20.文化移情_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(cultural empathy)21.全国翻译资格考试_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(CATTI(China Accreditation Test for Translators and Interpreters))22.短消息服务业务_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(SMS(Short Message Service))23.(美)中期选举_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(Midterm Election)24.中美洲自由贸易协定_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(Central American Free Trade Agreement)25.货币操纵国_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(currency manipulator)26.转基因食品_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(genetically modified food (GMF))27.自主创新能力_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(capacity of independent innovation)28.与时俱进_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(advance with the times; keep pace with the times; keep abreast of the times)29.贸易逆差_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(trade deficit)30.绿色国民经济_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(green national economy)31.风险投资_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________ 正确答案：(venture capital)32.早恋_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：(puppy love)二、英汉互译(总题数：6，分数：8.00)33.英译汉_________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________34.Many people believe that they will be happy once they arrive at some specific goal they set for them selves. However, more often than not, once you arrive "there" you will still feel dissatisfied, and move your "there" vision to yet another point in the future. By always chasing after another "there," you are never really appreciating what you already have right "here". It is important for human beings to keep sober-minded about the age-old drive to look beyond the place where you now stand. On one hand, your life is enhanced by your dreams and aspirations. On the other hand, these drives can pull you farther and farther from your enjoyment of your life right now. By learning the lessons of gratitude and abundance, you can bring yourself closer to fulfilling the challenge of living in the present._________________________________________________________________________________ _____________________________________________________________________________________ _____________________________________________________________________________________正确答案：( 许多人都相信，一旦他们达到了自己所设定的某个特定目标，他们就会开心、快乐。

(完整word版)电力电子技术经典试题.docx

1.什么是电力电子技术？答：应用于电力领域的、使用电力电子器件对电能进行变换和控制的技术。

是一门与电子、控制和电力紧密相关的边缘学科。

2.说“电力电子技术的核心技术是变流技术”对吗？答：对。

3.模拟电子技术和数字电子技术也是电力电子技术吗？答：不是。

4.举几例日常生活中应用电力电子技术的装置。

答：电动自行车的充电器，手机充电器，电警棍等。

5.简答“开关电源”和“线性电源”的主要优缺点。

答：开关电源：优点：体积小、重量轻、效率高、自身抗干扰性强、输入和输出的电压范围宽、可模块化。

缺点：由于开关工作模式和高频工作状态，对周围设备有一定的干扰。

需要良好的屏蔽及接地。

线性电源：优点：电源技术很成熟，可以达到很高的稳定度，波纹也很小，而且没有开关电源具有的噪声干扰。

缺点：是需要庞大而笨重的变压器，所需的滤波电容的体积和重量也相当大，效率低。

将逐步被开关电源所取代。

6.解释：不可控器件 ( 说明导通和关断的条件 ) 、半控型器件、全控型器件，并举出代表性器件的名称。

答：不可控器件：不用控制信号来控制其通、断。

导通和关断取决于其在主电路中承受电压的方向和大小。

典型器件：电力二极管导通条件：正向偏置，即承受正向电压，且正向电压＞阀值电压。

关断条件：反向偏置，即承受反向电压。

半控型器件：用控制信号来控制其导通，一旦导通门极就失去控制作用。

关断取决于其在主电路中承受的电压、电流的方向和大小。

典型器件：晶闸管1全控型器件：导通和关断均由电路的触发控制信号驱动（驱动状态需保持）。

典型器件： GTR、IGBT、 POWER MOSFET。

7.如图示的二极管伏安特性曲线，示意性地在坐标曲线上标注二极管的参数“反向击穿电压 UB”、“门槛电压 UTO”、“正向导通电流 IF ”及其对应的“正向压降 UF”、“反向漏电流”。

答：8.教科书 P42：第 4 题图中阴影部分为晶闸管处于通态区间的电流波形，各波形的电流最大值均为 Im，写出各波形的电流平均值 I d1、I d2、I d3与电流有效值 I 1、I 2、I 3的计算表达式(不必计算出结果)。

华科电气考研814电路2001年至2013年真题全解

华中科技大学2001年招收硕士研究生入学考试试题科目代码及名称：电路理论 814 适用专业：电气工程所有专业、环境工程1.（15分）电路如图所示，是列出其节点电位方程，并求出各独立电源、受控源发出的功率。

Ω2.（15分）电路如图所示，已知V U A I A I S S S 63221===，，，使用网络定理求电压表的读数。

S1S I Ω1Ω3.（15分）电路如图所示，图（a ）中运算放大器为理想运算放大器，求：1）输出电压与输入电压的关系：io u u ； 2）若)(t u i 的波形如图（b ），且Ω=101R Ω=10r ，画出)(t u o 的波形；3）试用一个理想运算放大器构造出对应于图（a ）的最简单的二端口等效电路。

+-i u o)4.（15分）如图所示电路，在开关K 闭合前电路已达到稳态，试求：t ≥0时的相应)(t u cc18V5.（15分）电路如图所示，若在双口网络左端口加一电压源)(t u s 。

求：（1）网络函数)()(s U s U H i o =；（2）冲激响应)(t u o ；（3）当t t u s sin 3)(=伏时，电路的正弦稳态响应)(t u o 。

(t u S )(t u o6.（15分）如图所示为以正序对称三相电路，图中三相负载铭牌上标出：额定线电压为V 3220，额定有功功率为23.232kW ，额定功率因数为0.8（感性）。

当电源的交频率s rad 100=ω，电源的相电压V E A 0220∠=∙，线路阻抗为Ω+=)21(j Z L ，电源端对地电容为F C μ20000=，电源的中性点接的电感为mH L N )350(=。

求：（1）三相负载的参数；（2）线路上的电流A I ∙，B I ∙及C I ∙（3）求当开关K 点闭合后，线路上的稳定电流A I ∙，B I ∙，C I ∙以及接地电感N L 的电流LN I ∙∙∙O7.（10分）如图所示电路，当V t u s 100)(=为直流电压源时，功率表的读数为400W ；将直流电压源)(t u s 换为非正弦电压源V t t u s )sin 290100()(ω+=时，安培表的读数为5A ，功率表的读数为670W ；此时若将电感L 断开，电压表读数为V 61618000，求参数1R ，2R ，L X 及1C X 。

2015年电子科技大学研究生入学考试《新闻与传播专业综合能力(专业硕士)》真题及答案

2015年电子科技大学研究生入学考试《新闻与传播专业综合能力（专业硕士）》真题(总分：150.00，做题时间：180分钟)一、材料分析题(总题数：1，分数：50.00)1.试从新闻报道的角度选择以及文稿的构成要素分析下面一篇新闻稿（要求结合稿件具体说明）。

火车站见证兰考经济变迁本报讯（记者童浩麟） 12 月 2 日下午 3 点 15 分，兰考县南彰镇徐洼村村民李麦花在新疆摘棉 94 天后，乘坐动 352 次火车回到了兰考。

94 天挣了 6100 元，比去年少了 2000 元。

“今年全国涌到新疆摘棉的人有 70 多万人，比去年又多了 10 万。

”李麦花说。

“今年兰考到新疆摘棉的明显减少。

”兰考县火车站总支书记何金峰说，“从火车站出发摘棉的约为 1.8 万人，比去年少了 8000 人。

”兰考县劳动和社会保障局统计数字显示，在 2008 年达到 18 万人次峰值以后，兰考劳务输出总数逐年回落。

今年前 10 个月，兰考就地转移劳力 6 万人，本地就业和外出务工人数比例达到了 74:26 。

“兰考的劳务经济，已从劳务输出进入到回乡创业和带动就业层面。

”兰考县劳动和社会保障局局长孔留书说，“劳务经济的变化和本地经济发展密不可分。

”自 2008 年起，兰考县委、县政府每年春节都举办“返乡创业明星评比活动”，在评出的 52 名创业明星中，无一不是上世纪 90 年代从兰考走出去的务工人员。

第五届创业明星古顺风回报家乡的是投资 1.5 亿元的生态农业科技园。

“公司已促使 2500 亩土地实现流转。

”古顺风说，“1 亩地 2 万元的效益，完全可以让村民不出村就挣钱。

”在古顺风生态农业科技园打工的城关镇姜楼村村民有 470 人，人均月收入 1600 元。

“在家门口就能养家，还能顾家，俺咋还会舍近求远外出打工呢？”村民齐庆竹说。

“兰考火车站虽然是陇海铁路线上一座普普通通的县城车站。

但却见证了兰考人民生存的几次改变。

”焦裕禄纪念园管理处副主任董亚娜说，“1962年焦裕禄来兰考的第一天，在火车站看到外出逃荒的群众直流泪。

2015电子科大考研试题814电力电子技术

2015电子科大考研试题814电力电子技术电子科技大学2015 年攻读硕士学位研究生入学考试试题考试科目：814 电力电子技术注：所有答案必须写在答题纸上，做在试卷或草稿纸上均无效。

一、单项选择题(每小题 2 分，共 28 分。

从每小题的四个备选答案，选出一个正确答案，并将正确答案的号码写在答题纸上。

) 1、经过直接交交变频的软启动器而接在交流电机上的电流频率不会超过A. 50Hz B. 5Hz C. 15Hz D. 400Hz 2、电流型逆变器中间直流环节贮能元件是。

A.电容 B.电感 C.蓄电池 3、压敏电阻在晶闸管整流电路中主要是用来 A. 分流 B. 降压 C. 过电压保护。

D.电动机。

D. 过电流保护4、逆导晶闸管是将大功率二极管与器件集成在一个管芯上而成。

A.大功率三极管B.逆阻型晶闸管C.双向晶闸管D.可关断晶闸管 5、单相全控桥反电动势负载电路中，当控制角α大于不导电角δ时，晶闸管的导通角θ 。

A.π-α B.π+α C.π-δ-α D.π+δ-α 6、在一般可逆电路中，最小逆变角βmin 选在下面那一种范围合理A.30o-35o B.10o-15o C.0o-10o D.0o 。

=7、对于三相半波可控整流电路，换相重叠角γ与哪几个参数有关。

A . α、负载电流 Id 以及变压器漏抗XB B. α以及负载电流IdC . α和U2 D. α、U2 以及变压器漏抗 XB 8、若增大 SPWM 逆变器的输出电压基波频率，可采用的控制方法是。

A.增大三角波幅度 B.增大三角波频率 C.增大正弦调制波频率 D.增大正弦调制波幅度 9、采用多重化电压源型逆变器的目的，主要是为 A.减小输出幅值 C.减小输出谐波。

B.增大输出幅值 D.减小输出功率负载。

10、晶闸管可控整流电路中直流端的直流电动机应该属于 A. 电阻性 B. 电感性 C. 反电动势 D. 阻感反电力电子技术试题第 1 页共 5 页11、功率晶体管 GTR 从高电压小电流向低电压大电流跃变的现象称为 A.一次击穿 B.二次击穿 C.临界饱和 D.反向截止 12、三相半波可控整流电路的自然换相点是A.交流相电压的过零点B.本相相电压与相邻相电压正半周的交点处 C.比三相不控整流电路的自然换相点超前30° D.比三相不控整流电路的自然换相点滞后60° 13、晶闸管两端并联一个 RC 电路的作用是 A. 分流 B. 降压 C. 过电压保护。