05研究生考题B
2005年全国硕士研究生考试英语真题及答案3精选全文完整版
精选全文完整版2005年全国硕士研究生考试英语真题及答案3Text 3Of all the components of a good night’s sleep, dreams seem to be least within our control. In dreams, a window opens into a world where logic is suspended and dead people speak. A century ago, Freud formulated his revolutionary theory that dreams were the disguised shadows of our unconscious desires and fears; by the late 1970s, neurologists had switched to thinking of them as just “mental noise” -- the random byproducts of the neural-repair work that goes on during sleep. Now researchers suspect that dreams are part of the mind’s emotional thermostat, regulating moods while the brain is “off-line.” And one leading authority says that these intensely powerful mental events can be not only harnessed but actually brought under conscious control, to help us sleep and feel better, “It’s your dream,” says Rosalind Cartwright, chair of psychology at Chicago’s Medical Center. “If you don’t like it, change it.”Evidence from brain imaging supports this view. The brain isas active during REM (rapid eye movement) sleep -- when most vivid dreams occur -- as it is when fully awake, says Dr, Eric Nofzinger at the University of Pittsburgh. But not all parts of the brain are equally involved; the limbic system (the “emotional brain”) is especially active, while the prefrontal cortex (the center of intellect and reasoning) is relatively quiet. “We wake up from dreams happy or depressed, and those feelings can stay with us all day.” says Stanford sleep researcher Dr. William Dement.The link between dreams and emotions show up among the patients in Cartwright’s clinic. Most people seem to have more bad dreams early in the night, progressing toward happier ones before awakening, suggesting that they are working through negative feelings generated during the day. Because our conscious mind is occupied with daily life we don’t always think about the emotional significance of the day’s events -- until, it appears, we begin to dream.And this process need not be left to the unconscious. Cartwright believes one can exercise conscious control over recurring bad dreams. As soon as you awaken, identify what is upsetting about the dream. Visualize how you would like it to end instead; the next time is occurs, try to wake up just enough to control itscourse. With much practice people can learn to, literally, do it in their sleep.At the end of the day, there’s probably little reason to pay attention to our dreams at all unless they keep us from sleeping or “we waken up in a panic,” Cartwright says. Terrorism, economic uncertainties and general feelings of insecurity have increased people’s anxiety. Those suffering from persistent nightmares should seek help from a therapist. For the rest of us, the brain has its ways of working through bad feelings. Sleep -- or rather dream -- on it and you’ll feel better in the morning.31. Researchers have come to believe that dreams ________.[A] can be modified in their courses[B] are susceptible to emotional changes[C] reflect our innermost desires and fears[D] are a random outcome of neural repairs32. By referring to the limbic system, the author intends to show ________.[A] its function in our dreams[B] the mechanism of REM sleep[C] the relation of dreams to emotions[D] its difference from the prefrontal cortex33. The negative feelings generated during the day tend to ________.[A] aggravate in our unconscious mind[B] develop into happy dreams[C] persist till the time we fall asleep[D] show up in dreams early at night34. Cartwright seems to suggest that ________.[A] waking up in time is essential to the ridding of bad dreams[B] visualizing bad dreams helps bring them under control[C] dreams should be left to their natural progression[D] dreaming may not entirely belong to the unconscious35. What advice might Cartwright give to those who sometimes have had dreams?[A] Lead your life as usual.[B] Seek professional help.[C] Exercise conscious control.[D] Avoid anxiety in the daytime.Text 4American no longer expect public figures, whether in speech or in writing, to command the English language with skill and gift. Nor do they aspire to such command themselves. In his latest book, Doing Our Own Thing: The Degradation of Language and Musicand Why We Should, Like, Care, John McWhorter, a linguist and controversialist of mixed liberal and conservative views, sees the triumph of 1960s counter-culture as responsible for the decline of formal English.Blaming the permissive 1960s is nothing new, but this is not yet another criticism against the decline in education. Mr. McWhorter’s academic speciality is language history and change, and he sees the gradual disappearance of “whom,” for example, to be natural and no more regrettable than the loss of the case-endings of Old English.But the cult of the aut hentic and the personal, “doing our own thing,” has spelt the death of formal speech, writing, poetry and music. While even the modestly educated sought an elevated tone when they put pen to paper before the 1960s, even the most well regarded writing since then has sought to capture spoken English on the page. Equally, in poetry, the highly personal, performative genre is the only form that could claim real liveliness. In both oral and written English, talking is triumphing over speaking, spontaneity over craft.Illustrated with an entertaining array of examples from both high and low culture, the trend that Mr. McWhorter documents is unmistakable. But it is less clear, to take the question ofhis subtitle, why we should, like, care. As a linguist, he acknowledges that all varieties of human language, including non-standard ones like Black English, can be powerfully expressive -- there exists no language or dialect in the world that cannot convey complex ideas. He is not arguing, as many do, that we can no longer think straight because we do not talk proper.Russians have a deep love for their own language and carry large chunks of memorized poetry in their heads, while Italian politicians tend to elaborate speech that would seem old-fashioned to most English-speakers. Mr. McWhorter acknowledges that formal language is not strictly necessary, and proposes no radical education reforms -- he is really grieving over the loss of something beautiful more than useful. We now take our English “on paper plates instead of china.”A shame, perhaps, but probably an inevitable one.36. According to McWhorter, the decline of formal English ________.[A] is inevitable in radical education reforms[B] is but all too natural in language development[C] has caused the controversy over the counter-culture[D] brought about changes in public attitudes in the 1960s37. The word “talking” (Line 6, paragraph 3) denotes ________.[A] modesty[B] personality[C] liveliness[D] informality38. To which of the following statements would McWhorter most likely agree?[A] Logical thinking is not necessarily related to the way we talk.[B] Black English can be more expressive than standard English.[C] Non-standard varieties of human language are just as entertaining.[D] Of all the varieties, standard English can best convey complex ideas.39. The description of Russians’ love of memorizing poetry shows the author’s ________.[A] interest in their language[B] appreciation of their efforts[C] admiration for their memory[D] contempt for their old-fashionedness40. According to the last paragraph, “paper plates” is to “china” as ________.[A] “temporary” is to “permanent”[B] “radical” is to “conservative”[C] “functional” is to “artistic”[D] “humble” is to “noble”。
05综合真题答案
2005年全国攻读工商管理硕士学位研究生入学考试综合考试试题答案数学真题答案： 1.B1108.5(107)8.5,15%210-+== 2.D80080018.5480280++=⨯⨯ 3.E2(5)20x ⇒++>原方程4.A使g(x)两侧异号的点对应C 1 , C 35.C2222222222()()()(,)2(,)8x y xy x x x y xyf x y xe e f x y xy e +++'=-''= 6.B 两条切线为43,26与轴围成三角形.底边上两顶点3坐标(,0)和(3,0),顶点y 坐标由43,26解得 3.41327于是图形面积为(3)3248y x y x x y x y x y =-=-+=-=-+=⨯-⨯= 7.A1110001100()()()(1)(1)(1)11x x f x dx xf x xf x dx e f x dx f e dx f x e '=--=+--=-⎰⎰⎰⎰⎰ 8.D 12312不成立反例:(1,0,0,0),(0,1,0,0),(0,0,1,0),(0,0,0,0),(0,0,0,1)D αααββ=====9.D10.C()0.6()()()0.6()()0.3()()()0.33()1()0.77()P A B P A P B P AB P B P AB P B A P B P BA P B A P A P A +=⇒+-=⇒-=-⇒====- 11.E"诊断为癌症""真患癌症"()()()()()()()()()0.020.950.0190.1620.020.950.980.10.117B A P A P B A P AB P A B P B P A P B A P A P B A ====+⨯===⨯+⨯ 12.C3(21)2()12142E X E X +=+=⨯+= 13.C><∆>⇒>>-+>⇒>⨯>⇒>+<⇒>++⇒<<021212(0)0,顶点0,5,2,2084014或a<6 (1)x 05 ( 2)x 02 ( 3)(1)(2)(3)56f x ba a a a a x a x a a 14.C0(1),(2)联合()()()0a a ab a a b a b ⎧<⇒⇒-+>+⎨+>⎩ 15.B3333762226(1)()3537(1)15ax C a a a ax C a a⎧-→-=-⎪⇒=-⎨-→=⎪⎩16.E122111[2]88284x a x dx adx a a --++-=⇒=⇒=⇒=⎰⎰17. D18.D1ln 为奇函数1x x -+ 19.B123(1)不充分如A=E,B=0(2)r(A)<r(,,,)3αααβ≤ 20.E1211010021()422,0,0A n r A A A ηη⎡⎤-=⎢⎥⎣⎦-=-=≠= 21.A12(1)20,2,充分(2)并不充分A βααβββ=+⇒≠=- 22.A 316(116)(1)0111(1)11116(2)6k x x a a a k =--=⇒=⎧⎪==⎨⎪⎩∑ 23.B=-=-≠-=⎰441321211(1)10.75163(2)(4)(0)4dx x x F F 逻辑真题答案24．答案选D 。
05年硕士研究生入学考试英语试题及答案
05年硕士研究生入学考试英语试题及答案Directions：Read the following text. Choose the best word（s）for each numbered blank and mark A, B, C or D on ANSWER SHEET 1（10 points） The human nose is an underrated tool. Humans are often thought to be insensitive smellers pared with animals, 1 this is largely because, 2 animals, we stand upright. This means that our noses are 3 to perceiving those smells which float through the air, 4 the majority of smells which stick to surfaces. In fact 5, we are extremely sensitive to smells, 6 we do not generally realize it. Our noses are capable of 7 human smells even when these are 8 to far below one part in one million. Strangely, some people find that they can smell one type of flower but not another, 9 others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate 10 smell receptors in the nose. These receptors are the cells which sense smells and send 11 to the brain. However, it has been found that even people insensitive to a certain smell 12 can suddenly bee sensitive to it when 13 to it often enough.The explanation for insensitivity to smell seems to be that brain finds it 14 to keep all smell receptors working allthe time but can 15 new receptors if necessary. This may 16 explain why we are not usually sensitive to our own smells we simply do not need to be. We are not 17 of the usual smell of our own house but we 18 new smells when we visit someone else's. The brain finds it best to keep smell receptors 19 for unfamiliar and emergency signals 20 the smell of smoke, which might indicate the danger of fire.1.[A]although[B]as[C]but[D]while2.[A]above[B]unlike[C]excluding[D]besides3.[A]limited[B]mitted[C]dedicated[D]confined4.[A]catching[B]ignoring[C]missing[D]tracking5.[A]anyway[B]though[C]instead[D]therefore6.[A]even if[B]if only[C]only if[D]as if7.[A]distinguishing[B]discovering[C]determining[D]detecting8.[A]diluted[B]dissolved[C]determining[D]diffused9.[A]when[B]since[C]for[D]whereas10.[A]unusual[B]particular[C]unique[D]typical11.[A]signs[B]stimuli[C]messages[D]impulses12.[A]at first[B]at all[C]at large[D]at times13.[A]subjected[B]left[C]drawn[D]exposed14.[A]ineffective[B]inpetent[C]inefficient[D]insufficient15.[A]introduce[B]summon[C]trigger[D]create16.[A]still[B]also[C]otherwise[D]nevertheless17.[A]sure[B]sick[C]aware[D]tired18.[A]tolerate[B]repel[C]neglect[D]notice19.[A]availabe[B]reliable[C]identifiable[D]suitable20.[A]similar to[B]such as[C]along with[D]aside from SectionⅡReading ComprehensionPart ADirections：Read the following four texts. Answer the questions below each text by choosing A, B, C or D. Mark your answers on ANSWER SHEET 1（40 points）Text 1Everybody loves a fat pay rise. Yet pleasure at your own can vanish if you learn that a colleague has been given a bigger one. Indeed, if he has a reputation for slacking, you might even be outraged. Such behaviour is regarded as“all too human”, with the underlying assumption that other animals would not be capable of this finely developed sense of grievance. But a study by Sarah Brosnan and Frans de Waal of Emory University inAtlanta, Georgia, which has just been published in Nature, suggests that it all too monkey, as well.The researchers studied the behaviour of female brown capuchin monkeys. They look cute. They are good-natured,co-operative creatures, and they share their food tardily. Above all, like their female human counterparts, they tend to pay much closer attention to the value of“goods and services”than males. Such characteristics make them perfect candidates for Dr. Brosnan's and Dr. de waal's；study. The researchers spent two years teaching their monkeys to exchange tokens for food. Normally, the monkeys were happy enough to exchange pieces of rock for slices of cucumber. However, when two monkeys were placed in separate but adjoining chambers, so that each could observe what the other was getting in return for its rock, their became markedly different.In the world of capuchins grapes are luxury goods（and much preferable to cucumbers）So when one monkey was handed a grape in exchange for her token, the second was reluctant to hand hers over for a mere piece of cucumber. And if one received a grape without having to provide her token in exchange at all, the other either tossed her own token at the researcher or out of the chamber, or refused to；aept the slice of cucumber Indeed,the mere presence of a grape in the other chamber（without an actual monkey to eat it）was enough to reduce resentment in a female capuchin.The researches suggest that capuchin monkeys, like humans, are guided by social emotions, in the wild, they are aco-operative, groupliving species, Such co-operation is likely to be stable only when each animal feels it is not being cheated. Feelings of righteous indignation, it seems, are not the preserve of people alone, Refusing a lesser reward pletely makes these feelings abundantly clear to other members of the group. However, whether such a sense of fairness evolved independently in capuchins and humans, or whether it stems form the mon ancestor that the species had 35 million years ago, is, as yet, an unanswered question.21. In the opening paragraph, the author introduces his topic byA. posing a contrast.B. justifying an assumption.C. making a parison.D. explaining a phenomenon.22. The statement“it is all too monkey”（Last line, paragraph l）implies thatA. monkeys are also outraged by slack rivals.B. resenting unfairness is also monkeys'nature.C. monkeys, like humans, tend to be jealous of each other.D. no animals other than monkeys can develop such emotions.23.Female capuchin monkeys were chosen for the research most probably because they areA. more inclined to weigh what they get.B. attentive to researchers'instructions.C. nice in both appearance and temperament.D. more generous than their male panions24.Dr. Brosnan and Dr. de Waal have eventually found in their study that the monkeysA. prefer grapes to cucumbers.B. can be taught to exchange things.C. will not be co-operative if feeling cheated.D. are unhappy when separated from others.25. What can we infer from the last paragraph？A. Monkeys can be trained to develop social emotions.B. Human indignation evolved from an uncertain source.C. Animals usually show their feelings openly as humans do.D. Cooperation among monkeys remains stable only in the wild.Text 2Do you remember all those years when scientists argued that smoking would kill us but the doubters insisted that we didn't know for sure？That the evidence was inconclusive, the science uncertain？That the antismoking lobby was out to destroy our way of life and the government should stay out of the way？Lots of Americans bought that nonsense, and over three decades, some 10 million smokers went to early graves.There are upsetting parallels today, as scientists in one wave after another try to awaken us to the growing threat of global warming. The latest was a panel from the National Academy of Sciences, enlisted by the White House, to tell us that the Earth's atmosphere is definitely warming and that the problem is largely man-made. The clear message is that we should get moving to protect ourselves. The president内容仅供参考。
考研英语05年真题试卷
考研英语05年真题试卷一、阅读理解（共30分）A节（共20分）Passage 1In recent years, the concept of lifelong learning has gained significant attention. It is widely believed that continuous education is essential for personal development and career advancement. The passage discusses the importance of lifelong learning and its impact on society.Questions 1-4 are based on the passage.1. What is the main idea of the passage?2. According to the passage, why is lifelong learning important for personal development?3. How does the author describe the impact of lifelong learning on society?4. What are some of the challenges faced by individuals pursuing lifelong learning?Passage 2The passage examines the role of technology in education. It explores how technological advancements have transformed the way students learn and teachers teach.Questions 5-8 are based on the passage.5. What is the main focus of the passage?6. How has technology changed the educational landscape?7. What are the benefits of integrating technology into education?8. What are some of the concerns regarding the use of technology in classrooms?B节（共10分）Passage 3This passage discusses the environmental impact of plastic waste and the efforts being made to reduce its usage.Questions 9-10 are based on the passage.9. What is the main concern addressed in the passage?10. What measures are being taken to address the issue of plastic waste?二、完形填空（共20分）For questions 11-30, read the following passage and choose the best answer from the four choices given.The story is about a young man who overcomes various challenges to achieve his dream of becoming a successful entrepreneur. The passage explores his journey, the obstacleshe faced, and the lessons he learned along the way.三、翻译（共20分）Translate the following sentences from English to Chinese.1. The rapid development of technology has brought about significant changes in our daily lives.2. It is crucial to balance work and leisure to maintain a healthy lifestyle.3. The government has implemented new policies to address the issue of air pollution.四、写作（共30分）Write an essay of about 200-250 words on the following topic: "The Influence of Social Media on Modern Society"Your essay should include an introduction, body paragraphs, and a conclusion. Discuss the positive and negative impacts of social media and provide your own perspective on the role of social media in today's world.请注意，以上内容为模拟的考研英语真题试卷，实际的真题试卷内容会有所不同。
北京交通大学企业管理专业真题解析
专业课真题详细解析(05年-09年)北京交通大学2005年硕士研究生入学考试试卷考试科目:管理学原理一、单项选择题（每题2分，共40分）1.现年32岁的李先生是某大型企业集团的总裁助理，工作十分出色，最近被提拔为集团生产总公司的总经理，从而从一个参谋角色转变为独立部门的直线管理负责人,在李先生近日参与的几项活动中，你认为以下哪一项最有可能与他的领导职能无关？(）A.与下属讨论对生产工作目标的认识B.与各分公司经理协商生产计划的落实情况C。
与某大学商讨有关未来技术合作事宜D。
召集公司有关部门的只能人员开联谊会，激励他们相互协作【参考答案】C【分析】A为计划,B为控制，D为激励。
C为作业工作,因此答案选C。
管理工作与作业工作.作业工作是指在组织中专门从事某项具体生产业务活动和专门技术工作的人员所进行的工作，他们大多位于一线，直接从事生产与技术工作；管理工作则是为作业工作提供服务的活动，从本质上讲,就是通过他人并使他人同自己一起去完成组织的目标和任务.2。
泰勒主张在企业中实行职能工长制，这一组织形式违反了：（）A。
分工原则 B。
权责对等原则 C。
统一指挥原则 D。
管理幅度原则【参考答案】C【分析】职能制组织缺点.容易形成多头领导,消弱统一指挥.3。
在现代管理理论学派中，哪一学派认为在企业管理中，没有什么一成不变、普遍使用的“最佳的”管理理论和方法？A。
管理过程学派 B。
行为科学学派 C。
系统管理学派 D.权变理论学派【参考答案】D【分析】权变理论观点。
该理论认为，并没有万能的、固定不变的有效领导类型，某种领导方式在实际工作中是否有效主要取决于具体的情景和场合,应当根据情境之不同而采取不同的领导方式,方位有效.没有最好的领导模式，只有最合适的领导模式。
4。
大邱庄在用人上总结出一条经验:大材小用，一般没用;小材大用,一般可用，这一现象说明：（）A。
人员的素质并不是起决定性作用的B.在乡镇企业中，高级人才的竞争力不如普通人C.学历并不是最重要的,重要的是真才实学和工作干劲D。
2005-考研真题
2005年全国硕士研究生入学统一考试英语试题Section I Use of EnglishDirections:Read the following text. Choose the best word(s) for each numbered blank and mark [A], [B], [C] or [D] on ANSWER SHEET 1(10 point s)The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, （1）_____ this is l argely because, （2）______ animals, we stand upright. This means t hat our noses are （3）______ to perceiving those smells which float through the air, （4）______ the majority of smells which stick to surf aces. In fact, （5）______ , we are extremely sensitive to smells, （6 ______ we do not generally realize it. Our noses are capable of （7）_ _____ human smells even when these are （8）______ to far below o ne part in one million.Strangely, some people find that they can smell one type of flowe r but not another, （9）______ others are sensitive to the smells of b oth flowers. This may be because some people do not have the genes necessary to generate （10）______ smell receptors in the nose. The se receptors are the cells which sense smells and send （11）______ to the brain. However, it has been found that even people insensitive to a certain smell （12）______ can suddenly become sensitive to it when （13）______ to it often enough.The explanation for insensitivity to smell seems to be that the bra in finds it （14）______ to keep all smell receptors working all the ti me but can （15）______ new receptors if necessary. This may （16_ _____ explain why we are not usually sensitive to our own smells—w e simply do not need to be. We are not （17）______ of the usual s mell of our own house, but we （18）______ new smells when we visi t someone else’s. The brain finds it best to keep smell receptors （19）______ for unfamiliar and emergency signals （20）______ the smell of smoke, which might indicate the danger of fire.1. [A] although[B] as[C] but[D] while2. [A] above[B] unlike[C] excluding[D] besides3.[A] limited[B] committed[C] dedicated[D] confined4.[A] catching[B] ignoring[C] missing[D] tracking5.[A] anyway[B] though[C] instead[D] therefore6.[A] even if[B] if only[C] only if[D] as if7.[A] distinguishing[B] discovering[C] determining[D] detecting8.[A] diluted[B] dissolved[C] dispersed[D] diffused9. [A] when[B] since[C] for[D] whereas10. [A] unusual[B] particular[C] unique[D] typical11. [A] signs[B] stimuli[C] messages[D] impulses12. [A] at first[B] at all[C] at large[D] at times13. [A] subjected[B] left[C] drawn[D] exposed14. [A] ineffective[B] incompetent[C] inefficient[D] insufficient15. [A] introduce[B] summon[C] trigger[D] create16. [A] still[B] also[C] otherwise[D] nevertheless17. [A] sure[B] sick[C] aware[D] tired18. [A] tolerate[B] repel[C] neglect[D] notice19. [A] available[B] reliable[C] identifiable[D] suitable20. [A] similar to[B] such as[C] along with[D] aside fromSection II Reading ComprehensionPart ADirections:Read the following four texts. Answer the questions below each text b y choosing [A], [B], [C] or D. Mark your answers on ANSWER SHEE T 1(40 points)Text 1Everybody loves a fat pay rise. Yet pleasure at your own can vani sh if you learn that a colleague has been given a bigger one. Indeed,if he has a reputation for slacking, you might even be outraged. Suc h behaviour is regarded as “all too human,” with the underlying assu mption that other animals would not be capable of this finely develop ed sense of grievance. But a study by Sarah Brosnan and Frans de W aal of Emory University in Atlanta, Georgia, which has just been publi shed in Nature, suggests that it is all too monkey, as well.The researchers studied the behaviour of female brown capuchin monkeys. They look cute. They are good-natured, co-operative creatur es, and they share their food readily. Above all, like their female hum an counterparts, they tend to pay much closer attention to the value of “goods and services” than males.Such characteristics make them perfect candidates for Dr. Brosna n’s and Dr. de Waal’s study. The researchers spent two years teaching their monkeys to exchange tokens for food. Normally, the monkeys were happy enough to exchange pieces of rock for slices of cucumber. However, when two monkeys were placed in separate but adjoining c hambers, so that each could observe what the other was getting in re turn for its rock, their behaviour became markedly different.In the world of capuchins, grapes are luxury goods (and much pr eferable to cucumbers). So when one monkey was handed a grape in exchange for her token, the second was reluctant to hand hers over for a mere piece of cucumber. And if one received a grape without ha ving to provide her token in exchange at all, the other either tossed her own token at the researcher or out of the chamber, or refused to accept the slice of cucumber. Indeed, the mere presence of a grape i n the other chamber (without an actual monkey to eat it) was enoug h to induce resentment in a female capuchin.The researchers suggest that capuchin monkeys, like humans, are guided by social emotions. In the wild, they are a co-operative, grou p-living species. Such co-operation is likely to be stable only when ea ch animal feels it is not being cheated. Feelings of righteous indignati on, it seems, are not the preserve of people alone. Refusing a lesser reward completely makes these feelings abundantly clear to other me mbers of the group. However, whether such a sense of fairness evolv ed independently in capuchins and humans, or whether it stems from the common ancestor that the species had 35 million years ago, is, as yet, an unanswered question.21. In the opening paragraph, the author introduces his topic by ________.[A] posing a contrast[B] justifying an assumption[C] making a comparison[D] explaining a phenomenon22. Th e statement “it is all too monkey” (Last line, Paragraph l) implies that ________.[A] monkeys are also outraged by slack rivals[B] resenting unfairness is also monkeys’ nature[C] monkeys, like humans, tend to be jealous of each other[D] no animals other than monkeys can develop such emotions23. Female capuchin monkeys were chosen for the research most probably because they are ________.[A] more inclined to weigh what they get[B] attentive to researchers’ instructions[C] nice in both appearance and temperament[D] more generous than their male companions24. Dr. Brosnan and Dr. de Waal have eventually found in their studythat the monkeys ________.[A] prefer grapes to cucumbers[B] can be taught to exchange things[C] will not be co-operative if feeling cheated[D] are unhappy when separated from others25. What can we infer from the last paragraph?[A] Monkeys can be trained to develop social emotions.[B] Human indignation evolved from an uncertain source.[C] Animals usually show their feelings openly as humans do.[D] Cooperation among monkeys remains stable only in the wild. Text 2Do you remember all those years when scientists argued that smo king would kill us but the doubters insisted that we didn’t know for s ure? That the evidence was inconclusive, the science uncertain? That the antismoking lobby was out to destroy our way of life and the gov ernment should stay out of the way? Lots of Americans bought that n onsense, and over three decades, some 10 million smokers went to e arly graves.There are upsetting parallels today, as scientists in one wave after another try to awaken us to the growing threat of global warming. T he latest was a panel from the National Academy of Sciences, enliste d by the White House, to tell us that the Earth’s atmosphere is defini tely warming and that the problem is largely man-made. The clear m essage is that we should get moving to protect ourselves. The preside nt of the National Academy, Bruce Alberts, added this key point in th e preface to the panel’s report: “Science n ever has all the answers. B ut science does provide us with the best available guide to the future, and it is critical that our nation and the world base important policie s on the best judgments that science can provide concerning the futu re consequences of present actions.”Just as on smoking, voices now come from many quarters insistin g that the science about global warming is incomplete, that it’s OK to keep pouring fumes into the air until we know for sure. This is a da ngerous game: by the time 100 percent of the evidence is in, it may be too late. With the risks obvious and growing, a prudent people wo uld take out an insurance policy now.Fortunately, the White House is starting to pay attention. But it’s obvious that a majority of the president’s advisers still don’t take glob al warming seriously. Instead of a plan of action, they continue to pre ss for more research -- a classic case of “paralysis by analysis.”To serve as responsible stewards of the planet, we must press for ward on deeper atmospheric and oceanic research. But research alone is inadequate. If the Administration won’t take the legislative initiativ e, Congress should help to begin fashioning conservation measures. A bill by Democratic Senator Robert Byrd of West Virginia, which would offer financial incentives for private industry, is a promising start. Ma ny see that the country is getting ready to build lots of new power pl ants to meet our energy needs. If we are ever going to protect the a tmosphere, it is crucial that those new plants be environmentally sou nd.26. An argument made by supporters of smoking was that ________.[A] there was no scientific evidence of the correlation between smoking and death[B] the number of early deaths of smokers in the past decades was insignificant[C] people had the freedom to choose their own way of life[D] antismoking people were usually talking nonsense27. According to Bruce Alberts, science can serve as ________.[A] a protector[B] a judge[C] a critic[D] a guide28. What does the author mean by “paralysis by analysis” (Last line,Paragraph 4)?[A] Endless studies kill action.[B] Careful investigation reveals truth.[C] Prudent planning hinders progress.[D] Extensive research helps decision-making.29. According to the author, what should the Administration do aboutglobal warming?[A] Offer aid to build cleaner power plants.[B] Raise public awareness of conservation.[C] Press for further scientific research.[D] Take some legislative measures.30. The author associates the issue of global warming with that of smoking because ________.[A] they both suffered from the government’s negligence[B] a lesson from the latter is applicable to the former[C] the outcome of the latter aggravates the former[D] both of them have turned from bad to worseText 3Of all the components of a good night’s sleep, dreams seem to be least within our control. In dreams, a window opens into a world wh ere logic is suspended and dead people speak. A century ago, Freud f ormulated his revolutionary theory that dreams were the disguised sh adows of our unconscious desires and fears; by the late 1970s, neuro logists had switched to thinking of them as just “mental noise” -- the random byproducts of the neural-repair work that goes on during sle ep. Now researchers suspect that dreams are part of the mind’s emot ional thermostat, regulating moods while the brain is “off-line.” And o ne leading authority says that these intensely powerful mental events can be not only harnessed but actually brought under conscious control, to help us sleep and feel better, “It’s your dream,” says Rosalind Cartwright, chair of psychology at Chicago’s Medical Center. “If you do n’t like it, change it.”Evidence from brain imaging supports this view. The brain is as a ctive during REM (rapid eye movement) sleep -- when most vivid dre ams occur -- as it is when fully awake, says Dr, Eric Nofzinger at the University of Pittsburgh. But not all parts of the brain are equally inv olved; the limbic system (the “emotional brain”) is especially active, while the prefrontal cortex (the center of intellect and reasoning) is re latively quiet. “We wake up from dreams happy or depressed, and tho se feelings can stay with us all day.” says Stanford sleep researcher D r. William Dement.The link between dreams and emotions shows up among the patie nts in Cartwright’s clinic. Most people seem to have more bad dreams early in the night, progressing toward happier ones before awakening, suggesting that they are working through negative feelings generated during the day. Because our conscious mind is occupied with daily lif e we don’t always think about the emotional significance of the day’s events -- until, it appears, we begin to dream.And this process need not be left to the unconscious. Cartwright b elieves one can exercise conscious control over recurring bad dreams. As soon as you awaken, identify what is upsetting about the dream. Visualize how you would like it to end instead; the next time it occur s, try to wake up just enough to control its course. With much practic e people can learn to, literally, do it in their sleep.At the end of the day, there’s probably little reason to pay attenti on to our dreams at all unless they keep us from sleeping or “we wa ke up in a panic,” Cartwright says. Terrorism, economic unc ertainties and general feelings of insecurity have increased people’s anxiety. Tho se suffering from persistent nightmares should seek help from a thera pist. For the rest of us, the brain has its ways of working through ba d feelings. Sleep -- or rather dream -- on it and you’ll feel better in t he morning.31. Researchers have come to believe that dreams ________.[A] can be modified in their courses[B] are susceptible to emotional changes[C] reflect our innermost desires and fears[D] are a random outcome of neural repairs32. By referring to the limbic system, the author intends to show ________.[A] its function in our dreams[B] the mechanism of REM sleep[C] the relation of dreams to emotions[D] its difference from the prefrontal cortex33. The negative feelings generated during the day tend to ________.[A] aggravate in our unconscious mind[B] develop into happy dreams[C] persist till the time we fall asleep[D] show up in dreams early at night34. Cartwright seems to suggest that ________.[A] waking up in time is essential to the ridding of bad dreams[B] visualizing bad dreams helps bring them under control[C] dreams should be left to their natural progression[D] dreaming may not entirely belong to the unconscious35. What advice might Cartwright give to those who sometimes havebad dreams?[A] Lead your life as usual.[B] Seek professional help.[C] Exercise conscious control.[D] Avoid anxiety in the daytime.Text 4Americans no longer expect public figures, whether in speech or i n writing, to command the English language with skill and gift. Nor d o they aspire to such command themselves. In his latest book, Doing Our Own Thing: The Degradation of Language and Music and Why We Should, Like, Care, John McWhorter, a linguist and controversialist of mixed liberal and conservative views, sees the triumph of 1960s cou nter-culture as responsible for the decline of formal English.Blaming the permissive 1960s is nothing new, but this is not yet another criticism a gainst the decline in education. Mr. McWhorter’s aca demic speciality is language history and change, and he sees the grad ual disappearance of “whom,” for example, to be natural and no moreregrettable than the loss of the case-endings of Old English.But t he cult of the authentic and the personal, “doing our own thi ng,” has spelt the death of formal speech, writing, poetry and music. While even the modestly educated sought an elevated tone when they put pen to paper before the 1960s, even the most well regarded wri ting since then has sought to capture spoken English on the page. Eq ually, in poetry, the highly personal, performative genre is the only fo rm that could claim real liveliness. In both oral and written English, t alking is triumphing over speaking, spontaneity over craft.Illustrated with an entertaining array of examples from both high and low culture, the trend that Mr. McWhorter documents is unmistak able. But it is less clear, to take the question of his subtitle, why we should, like, care. As a linguist, he acknowledges that all varieties of human language, including non-standard ones like Black English, can be powerfully expressive -- there exists no language or dialect in the world that cannot convey complex ideas. He is not arguing, as many do, that we can no longer think straight because we do not talk prop er.Russians have a deep love for their own language and carry large chunks of memorized poetry in their heads, while Italian politicians t end to elaborate speech that would seem old-fashioned to most Englis h-speakers. Mr. McWhorter acknowledges that formal language is not strictly necessary, and proposes no radical education reforms -- he is really grieving over the loss of something beautiful more than useful. We now take our English “on paper plates instead of china.” A shame, perhaps, but probably an inevitable one.36. According to McWhorter, the decline of formal English ________.[A] is inevitable in radical education reforms[B] is but all too natural in language development[C] has caused the controversy over the counter-culture[D] brought about changes in public attitudes in the 1960s37. The word “talking” (Line 6, Paragraph 3) denotes ________.[A] modesty[B] personality[C] liveliness[D] informality38. To which of the following statements would McWhorter most likelyagree?[A] Logical thinking is not necessarily related to the way we talk.[B] Black English can be more expressive than standard English.[C] Non-standard varieties of human language are just as entertaining.[D] Of all the varieties, standard English can best convey complex ideas.39. The description of Russians’ love of memorizing poetry shows theauthor’s ________.[A] interest in their language[B] appreciation of their efforts[C] admiration for their memory[D] contempt for their old-fashionedness40. According to the last paragraph, “paper plates” is to “china” as ________.[A] “temporary” is to “permanent”[B] “radical” is to “conservative”[C] “functional” is to “artistic”[D] “humble” is to “noble”Part BDirections:In the following text, some sentences have been removed. For Questi ons 41-45, choose the most suitable one from the list A-G to fit into each of the numbered blanks. There are two extra choices, which do not fit in any of the gaps. Mark your answers on ANSWER SHEET 1.(10 points)Canada’s premiers (the leaders of provincial governments), if they have any breath left after complaining about Ottawa at their late Jul y annual meeting, might spare a moment to do something, together, to reduce health-care costs.They’re all groaning about soaring health budgets, the fastest-gro wing component of which are pharmaceutical costs.41. ________What to do? Both the Romanow commission and the Kirby commit tee on health care -- to say nothing of reports from other experts -- recommended the creation of a national drug agency. Instead of each province having its own list of approved drugs, bureaucracy, procedu res and limited bargaining power, all would pool resources, work with Ottawa, and create a national institution.42. ________But “national” doesn’t have to mean that. “National” could mean i nterprovincial -- provinces combining efforts to create one body.Either way, one benefit of a “national” organization would be to n egotiate better prices, if possible, with drug manufacturers. Instead of having one province -- or a series of hospitals within a province -- n egotiate a price for a given drug on the provincial list, the national ag ency would negotiate on behalf of all provinces.Rather than, say, Quebec, negotiating on behalf of seven million p eople, the national agency would negotiate on behalf of 31 million pe ople. Basic economics suggests the greater the potential consumers, t he higher the likelihood of a better price.43. ________A small step has been taken in the direction of a national agency with the creation of the Canadian Co-ordinating Office for Health Tech nology Assessment, funded by Ottawa and the provinces. Under it, a Common Drug Review recommends to provincial lists which new drug s should be included. Predictably, and regrettably, Quebec refused to j oin.A few premiers are suspicious of any federal-provincial deal-makin g. They (particularly Quebec and Alberta) just want Ottawa to fork ov er additional billions with few, if any, strings attached. That’s one reas on why the idea of a national list hasn’t gone anywhere, while drug c osts keep rising fast.44. ________Premiers love to quote Mr. Romanow’s report selectively, especially the parts about more federal money. Perhaps they should read what he had to say about drugs: “A national drug agency would provide go vernments more influence on pharmaceutical companies in order to co nstrain the ever-increasing cost of drugs.”45. ________So when the premiers gather in Niagara Falls to assemble their us ual complaint list, they should also get cracking about something in their jurisdiction that would help their budgets and patients.[A] Quebec’s resistance to a national agency is provincialist ideology.One of the first advocates for a national list was a researcher at L aval University. Quebec’s Drug Insurance Fund has seen its costs skyrocket with annual increases from 14.3 per cent to 26.8 per ce nt![B] Or they could read Mr. Kirby’s report: “the substantial buying power of such an agency would strengthen the public prescription-drug insurance plans to negotiate the lowest possible purchase pricesfrom drug companies.”[C] What doe s “national” mean? Roy Romanow and Senator Michael Kirby recommended a federal-provincial body much like the recently created National Health Council.[D] The problem is simple and stark: health-care costs have been, are, and will continue to increase faster than government revenues.[E] According to the Canadian Institute for Health Information, prescription drug costs have risen since 1997 at twice the rate of overall health-care spending. Part of the increase comes from drugs being used to replace other kinds of treatments. Part of it arises fromnew drugs costing more than older kinds. Part of it is higher pric es.[F] So, if the provinces want to run the health-care show, they should prove they can run it, starting with an interprovincial health listthat would end duplication, save administrative costs, prevent one province from being played off against another, and bargain forbetter drug prices.[G] Of course, the pharmaceutical companies will scream. They like divided buyers; they can lobby better that way. They can use the t hreat of removing jobs from one province to another. They can ho pe that, if one province includes a drug on its list, the pressure w ill cause others to include it on theirs. They wouldn’t like a nation al agency, but self-interest would lead them to deal with it.Part CDirections:Read the following text carefully and then translate the underlined se gments into Chinese. Your translation should be written clearly on AN SWER SHEET 2. (10 points)It is not easy to talk about the role of the mass media in this overwhelmingly significant phase in European history. History and news become confused, and one’s impressions tend to be a mixture of skep ticism and optimism. 46) Television is one of the means by which the se feelings are created and conveyed -- and perhaps never before ha s it served so much to connect different peoples and nations as in th e recent events in Europe. The Europe that is now forming cannot be anything other than its peoples, their cultures and national identities. With this in mind we can begin to analyze the European television sc ene. 47) In Europe, as elsewhere, multi-media groups have been incr easingly successful: groups which bring together television, radio, new spapers, magazines and publishing houses that work in relation to on e another. One Italian example would be the Berlusconi group, while abroad Maxwell and Murdoch come to mind.Clearly, only the biggest and most flexible television companies ar e going to be able to compete in such a rich and hotly-contested mar ket. 48) This alone demonstrates that the television business is not a n easy world to survive in, a fact underlined by statistics that show t hat out of eighty European television networks, no less than 50% too k a loss in 1989.Moreover, the integration of the European community will oblige t elevision companies to cooperate more closely in terms of both produ ction and distribution.49) Creating a “European identity” that respects the different cult ures and traditions which go to make up the connecting fabric of the Old Continent is no easy task and demands a strategic choice -- that of producing programs in Europe for Europe. This entails reducing our dependence on the North American market, whose programs relate t o experiences and cultural traditions which are different from our ow n.In order to achieve these objectives, we must concentrate more o n co-productions, the exchange of news, documentary services and tr aining. This also involves the agreements between European countries for the creation of a European bank for Television Production which, on the model of the European Investments Bank, will handle the fina nces necessary for production costs. 50) In dealing with a challenge o n such a scale, it is no exaggeration to say “United we stand, divided we fall”-- and if I had to choose a slogan it would be “Unity in our diversity.” A unity of objectives that nonetheless respect the varied pe culiarities of each country.Section III WritingPart A51. Directions:Two months ago you got a job as an editor for the magazine Desi gns & Fashions. But now you find that the work is not what you expe cted. You decide to quit. Write a letter to your boss, Mr. Wang, telling him your decision, stating your reason (s), and making an apology.Write your letter with no less than 100 words. Write it neatly on ANSWER SHEET 2.Do not sign your own name at the end of the letter; use “Li Min g” instead.You do not need to write the address. (10 points)Part B52. Directions:Write an essay of 160-200 words based on the following drawing. In your essay, you should first describe the drawing, then interpret its m eaning, and give your comment on it.You should write neatly on ANSWER SHEET 2. (20 points)。
GCT_2005年考试真题及答案(整理好的,可直接打印)
2005年硕士专业学位研究生入学资格考试试卷第一部分语言表达能力测试（50题，每题2分，满分100分）一、选择题1．下面各组词语中，没有错别字的一组是：A．乐此不彼密云不雨墨守成规循规蹈矩 B．靡靡之音诲人不倦漫不经心循循善诱C．坚守自盗杀鸡儆猴出人头地力挽狂澜D．投机取巧骇人听闻目不瑕接龙潭虎穴2．下列加点字的释义全都正确的是A．失宠（偏爱）韬（显示）光养晦老骥伏枥（马槽）B．爽（失）约马革（皮）裹尸作茧自缚（捆绑）C．舞蹈（顿足）既往不咎（过错）悲天悯（怜惜）人D．龌龊（肮脏）不知端倪（头绪）臭（难闻的）味相投3．下没有语病的一句是A．“费改税”能否遏制住愈演愈烈的乱收费现象，这对农村工作是个考验。
B．亚健康状态，往往受到无规律的生活和沉重的学习工作压力而引起。
C．一听说有盛夏的免费音乐节，许多的附近居民早早就赶来，等待观看。
D．就反腐败这样一个国际性的顽疾来说，“公开”是最有效的一剂良药。
4．下面各句中，语意明确、没有歧义的一句是A．据外电报道，昨日新加坡一油轮起火爆炸。
B．小李见老王把他的书撕了，便揪住老王让他赔。
C．几个公司的领导对这个调整方案意见不一，争执不下。
D．工作组来我县调查的前三天，整个县城就己沸沸扬扬。
5．对下面这段话使用的修辞手法分析不当的一项是风是调皮的小男孩，抓把土抛到空中，趁机扯乱女孩子的长发；风是年老的画家，一味选灰色调，造出黄昏的画面；风是不高明的小偷，溜进屋时弄响了门，逃走时还在窗上留下了脚印。
A．这段话使用了拟人的修辞手法。
B．这段话运用了三个长度、句式风格相近的句子，这是排比的修辞手法。
C．这段话使用了明喻，分别把风比作“小男孩”、“年老的画家”、“小偷”。
D．这段话中几种修辞方法结合得不露痕迹，恰到好处。
6．下面这首古诗描述了我国民间一个传统节令的景象，这个节令是中庭地白树栖鸦，冷露无声湿桂花。
今夜月明人尽望，不知秋思落谁家？A．重阳 B．七夕 C．中秋 D．元宵7．下面表述不正确的一项是A．13世纪的《马可·波罗行记》是最早较系统地向欧洲介绍中国的一部游记。
05年考研英语真题(题目选项版)
05Text 121. In the opening paragraph, the author introduces his topic by________.[A] posing a contrast[B] justifying an assumption[C] making a comparison[D] explaining a phenomenon22. The statement “it is all too monkey” (Last line, Paragraph l) implies that ________.[A] monkeys are also outraged by slack rivals[B] resenting unfairness is also monkeys’ nature[C] monkeys, like humans, tend to be jealous of each other[D] no animals other than monkeys can develop such emotions23. Female capuchin monkeys were chosen for the research most probably because they are ________.[A] more inclined to weigh what they get[B] attentive to researchers’ instructions[C] nice in both appearance and temperament[D] more generous than their male companions24. Dr. Brosnan and Dr. de Waal have eventually found in their study that the monkeys ________.[A] prefer grapes to cucumbers[B] can be taught to exchange things[C] will not be co-operative if feeling cheated[D] are unhappy when separated from others25. What can we infer from the last paragraph?[A] Monkeys can be trained to develop social emotions.[B] Human indignation evolved from an uncertain source.[C] Animals usually show their feelings openly as humans do.[D] Cooperation among monkeys remains stable only in the wild.Text 226. An argument made by supporters of smoking was that ________.[A] there was no scientific evidence of the correlation between smoking and death[B] the number of early deaths of smokers in the past decades was insignificant[C] people had the freedom to choose their own way of life[D] antismoking people were usually talking nonsense27. According to Bruce Alberts, science can serve as ________.[A] a protector[B] a judge[C] a critic[D] a guide28. What does the author mean by “paralysis by analysis” (Last line, Paragraph 4)?[A] Endless studies kill action.[B] Careful investigation reveals truth.[C] Prudent planning hinders progress.[D] Extensive research helps decision-making.29. According to the author, what should the Administration do about global warming?[A] Offer aid to build cleaner power plants.[B] Raise public awareness of conservation.[C] Press for further scientific research.[D] Take some legislative measures.30. The author associates the issue of global warming with that of smoking because ________.[A] they both suffered from the government’s negligence[B] a lesson from the latter is applicable to the former[C] the outcome of the latter aggravates the former[D] both of them have turned from bad to worseText 331. Researchers have come to believe that dreams ________.[A] can be modified in their courses[B] are susceptible to emotional changes[C] reflect our innermost desires and fears[D] are a random outcome of neural repairs32. By referring to the limbic system, the author intends to show________.[A] its function in our dreams[B] the mechanism of REM sleep[C] the relation of dreams to emotions[D] its difference from the prefrontal cortex33. The negative feelings generated during the day tend to ________.[A] aggravate in our unconscious mind[B] develop into happy dreams[C] persist till the time we fall asleep[D] show up in dreams early at night34. Cartwright seems to suggest that ________.[A] waking up in time is essential to the ridding of bad dreams[B] visualizing bad dreams helps bring them under control[C] dreams should be left to their natural progression[D] dreaming may not entirely belong to the unconscious35. What advice might Cartwright give to those who sometimes have bad dreams?[A] Lead your life as usual.[B] Seek professional help.[C] Exercise conscious control.[D] Avoid anxiety in the daytime.Text 436. According to McWhorter, the decline of formal English ________.[A] is inevitable in radical education reforms[B] is but all too natural in language development[C] has caused the controversy over the counter-culture[D] brought about changes in public attitudes in the 1960s37. The word “talking” (Line 6, Paragraph 3) denotes ________.[A] modesty[B] personality[C] liveliness[D] informality38. To which of the following statements would McWhorter most likely agree?[A] Logical thinking is not necessarily related to the way we talk.[B] Black English can be more expressive than standard English.[C] Non-standard varieties of human language are just as entertaining.[D] Of all the varieties, standard English can best convey complex ideas.39. The description of Russians’ love of memorizing poetry shows the author’s ________.[A] interest in their language[B] appreciation of their efforts[C] admiration for their memory[D] contempt for their old-fashionedness40. According to the last paragraph, “paper plates” is to “china”as ________.[A] “temporary” is to “permanent”[B] “radical” is to “conservative”[C] “functional” is to “artistic”[D] “humble” is to “noble”__。
2005年考研数学二试题及答案
2005年数学二试题分析、详解和评注一、填空题（本题共6小题，每小题4分，满分24分。
把答案填在题中横线上）（1）设xx y )sin 1(+=,则π=x dy= 。
(2） 曲线xx y 23)1(+=的斜渐近线方程为。
(3)=--⎰1221)2(xxxdx（4） 微分方程x x y y x ln 2=+'满足91)1(-=y 的解为（5）当0→x 时,2)(kx x =α与x x x x cos arcsin 1)(-+=β是等价无穷小，则k= .（6)设321,,ααα均为3维列向量，记矩阵),,(321ααα=A ，)93,42,(321321321ααααααααα++++++=B , 如果1=A ，那么=B 。
二、选择题(本题共8小题，每小题4分,满分32分. 每小题给出的四个选项中,只有一项符合题目要求，把所选项前的字母填在题后的括号内）（7）设函数n nn xx f 31lim )(+=∞→，则f(x ）在),(+∞-∞内（A ） 处处可导。
（B ） 恰有一个不可导点。
（C ） 恰有两个不可导点. （D ） 至少有三个不可导点。
［ ] （8）设F(x ）是连续函数f （x ）的一个原函数，""N M ⇔表示“M 的充分必要条件是N ”，则必有(A) F （x ）是偶函数⇔f(x)是奇函数。
(B ） F （x)是奇函数⇔f （x ）是偶函数。
（C ） F(x)是周期函数⇔f(x)是周期函数.(D ） F （x ）是单调函数⇔f （x ）是单调函数。
［ ］（9)设函数y=y(x ）由参数方程⎩⎨⎧+=+=)1ln(,22t y t t x 确定，则曲线y=y （x ）在x=3处的法线与x 轴交点的横坐标是(A) 32ln 81+。
(B) 32ln 81+-. （C) 32ln 8+-. (D) 32ln 8+。
［ ］（10）设区域}0,0,4),{(22≥≥≤+=y x y x y x D ，f （x ）为D 上的正值连续函数，a,b 为常数，则=++⎰⎰σd y f x f y f b x f a D)()()()((A) πab 。
【考研必备】2005年考研英语真题及解析
[日期] 2 005 年全国硕士研究生入学统一考试英语试题Section I Use of EnglishDirections:Read the following text. Choose the best word(s) for each numbered blank and mark [A], [B], [C] or [D] on ANSWER SHEET 1 (10 points)The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, 1 this is largely because, 2animals, we stand upright. This means that our noses are 3 to perceiving those smells which float through the air, 4 the majority of smells which stick to surfaces. In fact, 5 , we are extremely sensitive to smells, 6 we do not generally realize it. Our noses are capable of 7 human smells even when these are 8 to far below one part in one million.Strangely, some people find that they can smell one type of flower but not another, 9 others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate 10 smell receptors in the nose. These receptors are the cells which sense smells and send 11to the brain. However, it has been found that even peopleinsensitive to a certain smell12 can suddenly become sensitive to it when 13to it often enough.The explanation for insensitivity to smell seems to be that brain finds it 14 to keep all smell receptors working all the time but can 15 new receptors if necessary. This may 16 explain why we are not usually sensitive to our own smells —we simply do not need to be. We are not 17 of the usual smell of our own house, but we 18 new smells when we visit someone else’s. The brain finds it best to keep smell receptors 19 for unfamiliar and emergency signals 20 the smell of smoke, which might indicate the danger of fire.1 2 3 4 5 6 7 8 9 1 1 1 1 1 .[A] although .[A] above [B] as [C] but [D] while[B] unlike [B] committed [B] ignoring [B] though [B] if only [C] excluding [C] dedicated [C] missing [C] instead [C] only if [D] besides[D] confined[D] tracking[D] therefore[D] as if.[A] limited .[A] catching .[A] anyway .[A] even if .[A]distinguishing [B] discovering [C] determining [D] detecting.[A] diluted .[A] when [B] dissolved [B] since [C] dispersed [C] for [D] diffused[D] whereas[D] typical0.[A] unusual 1.[A] signs [B] particular [B] stimuli [B] at all [C] unique [C] messages [C] at large [C] drawn [D] impulses[D] at times[D] exposed[D] insufficient2.[A] at first3.[A] subjected [B] left4.[A] ineffective [B] incompetent [C] inefficient1 1 1 27.[A]sure[B]sick[C]aware[C]neglect[D]tired[D]notice8.[A]tolerate9.[A]available0.[A]similar to[B]repel[B]reliable[C]identifiable[D]suitable[B]such as[C]along with[D]aside fromSection II Reading ComprehensionPart ADirections:Read the following four texts.Answer the questions below each text by choosing[A],[B],[C]or[D].Mark your answers on ANSWER SHEET1.(40points)Text1Everybody loves a fat pay rise.Yet pleasure at your own can vanish if you learn that a colleague has been given a bigger one.Indeed,if he has a reputation for slacking,you might even be outraged.Such behaviour is regarded as“all too human”,with the underlying assumption that other animals would not be capable of this finely developed sense of grievance.But a study by Sarah Brosnan and Frans de Waal of Emory University in Atlanta,Georgia,which has just been published in Nature,suggests that it is all too monkey,as well.The researchers studied the behaviour of female brown capuchin monkeys.They look cute.They are good-natured,co-operative creatures,andthey share their food readily.Above all,like their female human counterparts,they tend to pay much closer attention to the value of“goods and services”than males.Such characteristics make them perfect candidates for Dr.Brosnan’s and Dr.de Waal’s study.The researchers spent two years teaching their monkeys to exchange tokens for food.Normally,the monkeys were happy enough to exchange pieces of rock for slices of cucumber.However,when two monkeys were placed in separate but adjoining chambers,so that each could observe what the other was getting in return for its rock,their behaviour became markedly different.In the world of capuchins grapes are luxury goods(and much preferable to cucumbers).So when one monkey was handed a grape in exchange for her token,the second was reluctant to hand hers over for a mere piece of cucumber.And if one received a grape without having to provide her token in exchange at all,the other either tossed her own token at the researcher or out of the chamber,or refused to accept the slice of cucumber.Indeed, the mere presence of a grape in the other chamber(without an actual monkey to eat it)was enough to induce resentment in a female capuchin.The researchers suggest that capuchin monkeys,like humans,are guided by social emotions.In the wild,they are a co-operative,group-living species.Such co-operation is likely to be stable only when each animal feels it is not being cheated.Feelings of righteous indignation,it seems,are not the preserve of people alone.Refusing a lesser reward completely makes these feelings abundantly clear to other members of the group.However, whether such a sense of fairness evolved independently in capuchins and humans,or whether it stems from the common ancestor that the species had35million years ago,is,as yet,an unanswered question.21.In the opening paragraph,the author introduces his topic by________.[ [ [ [A]posing a contrastB]justifying an assumptionC]making a comparisonD]explaining a phenomenon22.The statement“it is all too monkey”(Last line,Paragraph l)implies that________.[ [ [ [A]monkeys are also outraged by slack rivalsB]resenting unfairness is also monkeys’natureC]monkeys,like humans,tend to be jealous of each otherD]no animals other than monkeys can develop such emotions23.Female capuchin monkeys were chosen for the research most probably because they are________.[A]more inclined to weigh what they get[B]attentive to researchers’instructions[C]nice in both appearance and temperament[D]more generous than their male companions24.Dr.Brosnan and Dr.de Waal have eventually found in their study that the monkeys________.[ [ [ [A]prefer grapes to cucumbersB]can be taught to exchange thingsC]will not be co-operative if feeling cheatedD]are unhappy when separated from others25.What can we infer from the last paragraph?[A]Monkeys can be trained to develop social emotions.[B]Human indignation evolved from an uncertain source.[C]Animals usually show their feelings openly as humans do.[D]Cooperation among monkeys remains stable only in the wild.Text2Do you remember all those years when scientists argued that smoking would kill us but the doubters insisted that we didn’t know for sure?That the evidence was inconclusive,the science uncertain?That the antismoking lobby was out to destroy our way of life and the government should stay out of the way?Lots of Americans bought that nonsense,and over three decades,some10million smokers went to early graves.There are upsetting parallels today,as scientists in one wave after another try to awaken us to the growing threat of global warming.The latestwas a panel from the National Academy of Sciences,enlisted by the White House,to tell us that the Earth’s atmosphere is definitely warming and that the problem is largely man-made. The clear message is that we should get moving to protect ourselves.The president of the National Academy, Bruce Alberts,added this key point in the preface to the panel’s report:“Science never has all the answers.But science does provide us with the best available guide to the future,and it is critical that our nation and the worldbase important policies on the best judgments that science can provide concerning the future consequences of present actions.”Just as on smoking,voices now come from many quarters insisting that the science about global warming is incomplete,that it’s OK to keep pouring fumes into the air until we know for sure.This is a dangerous game:by the time100percent of the evidence is in,it may be too late.With the risks obvious and growing,a prudent people would take out an insurance policy now.Fortunately,the White House is starting to pay attention.But it’s obvious that a majority of the president’s advisers still don’t take global warming seriously.Instead of a plan of action,they continue to press for more research—a classic case of“paralysis by analysis”.To serve as responsible stewards of the planet,we must press forward on deeper atmospheric and oceanic research.But research alone is inadequate.If the Administration won’t take the legislative initiative,Congress should help to begin fashioning conservation measures.A bill by Democratic Senator Robert Byrd of West Virginia,which would offer financial incentives for private industry,is a promising start.Many see that the country is getting ready to build lots of new power plants to meet our energy needs.If we are ever going to protect the atmosphere,it is crucial that those new plants be environmentally sound.26.An argument made by supporters of smoking was that________.[ [ [ [A]there was no scientific evidence of the correlation between smoking and deathB]the number of early deaths of smokers in the past decades was insignificantC]people had the freedom to choose their own way of lifeD]antismoking people were usually talking nonsense27.According to Bruce Alberts,science can serve as________.[ [ [ [A]a protectorB]a judgeC]a criticD]a guide28.What does the author mean by“paralysis by analysis”(Last line,Paragraph4)?[ [ [ [A]Endless studies kill action.B]Careful investigation reveals truth.C]Prudent planning hinders progress.D]Extensive research helps decision-making.29.According to the author,what should the Administration do about global warming?[A]Offer aid to build cleaner power plants.[B]Raise public awareness of conservation.[C]Press for further scientific research.[D]Take some legislative measures.30.The author associates the issue of global warming with that of smoking because______.[A]they both suffered from the government’s negligenceB]a lesson from the latter is applicable to the former[[C]the outcome of the latter aggravates the formerD]both of them have turned from bad to worse[Text3Of all the components of a good night’s sleep,dreams seem to be least within our control.In dreams,a window opens into a world where logic is suspended and dead people speak.A century ago,Freud formulated his revolutionary theory that dreams were the disguised shadows of our unconscious desires and fears;by the late 1970s,neurologists had switched to thinking of them as just“mental noise”—the random byproducts of the neural-repair work that goes on during sleep.Now researcherssuspect that dreams are part of the mind’s emotional thermostat,regulating moods while the brain is“off-line.”And one leading authority says that these intensely powerful mental events can be not only harnessed but actually brought under conscious control,to help us sleep and feel better.“It’s your dream,”says Rosalind Cartwright,chair of psychology at Chicago’s Medical Center.“If you don’t like it,change it.”Evidence from brain imaging supports this view.The brain is as active during REM(rapid eye movement) sleep—when most vivid dreams occur—as it is when fully awake,says Dr.Eric Nofzinger at the University of Pittsburgh.But not all parts of the brain are equally involved;the limbic system(the“emotional brain”)is especially active,while the prefrontal cortex(the center of intellect and reasoning)is relatively quiet.“We wake up from dreams happy or depressed,and those feelings can stay with us all day.”says Stanford sleep researcher Dr.William Dement.The link between dreams and emotions shows up among the patients in Cartwright’s clinic.Most people seem to have more bad dreams early in the night,progressing toward happier ones before awakening,suggesting that they are working through negative feelings generated during the day.Because our conscious mind is occupied with daily life we don’t always think about the emotional significance of the day’s events—until,it appears,we begin to dream.And this process need not be left to the unconscious.Cartwright believes one can exercise conscious control over recurring bad dreams.As soon as you awaken,identify what is upsetting about the dream.Visualize how you would like it to end instead;the next time it occurs,try to wake up just enough to control its course.With much practice people can learn to,literally,do it in their sleep.At the end of the day,there’s probably little reason to pay attention to our dreams at all unless they keep us from sleeping or“we wake up in a panic,”Cartwright says.Terrorism,economic uncertainties and general feelings of insecurity have increased people’s anxiety.Those suffering from persistent nightmares should seek help from a therapist.For the rest of us,the brain has its ways of working through bad feelings.Sleep—or rather dream—on it and you’ll feel better in the morning.31.Researchers have come to believe that dreams________.[ [ [A]can be modified in their coursesB]are susceptible to emotional changesC]reflect our innermost desires and fears[D]are a random outcome of neural repairs32.By referring to the limbic system,the author intends to show________.[ [ [ [A]its function in our dreamsB]the mechanism of REM sleepC]the relation of dreams to emotionsD]its difference from the prefrontal cortex33.The negative feelings generated during the day tend to________.[ [ [ [A]aggravate in our unconscious mindB]develop into happy dreamsC]persist till the time we fall asleepD]show up in dreams early at night34.Cartwright seems to suggest that________.[A]waking up in time is essential to the ridding of bad dreams[B]visualizing bad dreams helps bring them under control[C]dreams should be left to their natural progression[D]dreaming may not entirely belong to the unconscious35.What advice might Cartwright give to those who sometimes have bad dreams?[ [ [ [A]Lead your life as usual.B]Seek professional help.C]Exercise conscious control.D]Avoid anxiety in the daytime.Text4Americans no longer expect public figures,whether in speech or in writing,to command the Englishlanguage with skill and gift.Nor do they aspire to such command themselves.In his latest book,Doing Our Own Thing:The Degradation of language and Music and Why We Should Like,Care,John McWhorter,a linguist and controversialist of mixed liberal and conservative views,sees the triumph of1960s counter-culture as responsible for the decline of formal English.Blaming the permissive1960s is nothing new,but this is not yet another criticism against the decline in education.Mr.McWhorter’s academic speciality is language history and change,and he sees the gradual disappearance of“whom”,for example,to be natural and no more regrettable than the loss of the case-endings of Old English.But the cult of the authentic and the personal,“doing our own thing”,has spelt the death of formal speech, writing,poetry and music.While even the modestly educated sought an elevated tone when they put pen to paper before the1960s,even the most well regarded writing since then has sought to capture spoken English on the page.Equally,in poetry,the highly personal,performative genre is the only form that could claim real liveliness. In both oral and written English,talking is triumphing over speaking,spontaneity over craft.Illustrated with an entertaining array of examples from both high and low culture,the trend that Mr. McWhorter documents is unmistakable.But it is less clear,to take the question of his subtitle,why we should, like,care.As a linguist,he acknowledges that all varieties of human language,including non-standard ones like Black English,can be powerfully expressive—there exists no language or dialect in the world that cannot convey complex ideas.He is not arguing,as many do,that we can no longer think straight because we do not talk proper. Russians have a deep love for their own language and carry large chunks of memorized poetry in their heads, while Italian politicians tend to elaborate speech that would seem old-fashioned to most English-speakers.Mr. McWhorter acknowledges that formal language is not strictly necessary,and proposes no radical education reforms—he is really grieving over the loss of something beautiful more than useful.We now take our English “on paper plates instead of china”.A shame,perhaps,but probably an inevitable one.6.According to McWhorter,the decline of formal English________.3[ [ [ [A]is inevitable in radical education reformsB]is but all too natural in language developmentC]has caused the controversy over the counter-cultureD]brought about changes in public attitudes in the1960s37.The word“talking”(Line6,Paragraph3)denotes________.[ [ [ [A]modestyB]personalityC]livelinessD]informality38.To which of the following statements would McWhorter most likely agree?[A]Logical thinking is not necessarily related to the way we talk.[B]Black English can be more expressive than standard English.[C]Non-standard varieties of human language are just as entertaining.[D]Of all the varieties,standard English can best convey complex ideas.39.The description of Russians’love of memorizing poetry shows the author’s________.[ [ [ [A]interest in their languageB]appreciation of their effortsC]admiration for their memoryD]contempt for their old-fashionedness40.According to the last paragraph,“paper plates”is to“china”as________.[A]“temporary”is to“permanent”[B]“radical”is to“conservative”[C]“functional”is to“artistic”[D]“humble”is to“noble”Part BDirections:In the following text,some sentences have been removed.For Questions41-45,choose the most suitable one from the list A-G to fit into each of the numbered blanks.There are two extra choices,which do not fit in any of the gaps.Mark your answers on ANSWER SHEET1.(10points)Canada’s premiers(the leaders of provincial governments),if they have any breath left after complaining about Ottawa at their late July annual meeting,might spare a moment to do something,together,to reduce health-care costs.They’re all groaning about soaring health budgets,the fastest-growing component of which are pharmaceutical costs.(41)____________What to do?Both the Romanow commission and the Kirby committee on health care—to say nothing of reports from other experts—recommended the creation of a national drug agency.Instead of each province having its own list of approved drugs,bureaucracy,procedures and limited bargaining power,all would pool resources, work with Ottawa,and create a national institution.(42)_____________But“national”doesn’t have to mean that.“National”could mean interprovincial—provinces combining effortsto create one body.Either way,one benefit of a“national”organization would be to negotiate better prices,if possible,with drug manufacturers.Instead of having one province—or a series of hospitals within a province—negotiate a price for a given drug on the provincial list,the national agency would negotiate on behalf of all provinces.Rather than,say,Quebec,negotiating on behalf of seven million people,the national agency would negotiate on behalf of31million people.Basic economics suggests the greater the potential consumers,the higher the likelihood of a better price.(43)_____________A small step has been taken in the direction of a national agency with the creation of the Canadian Co-ordinating Office for Health Technology Assessment,funded by Ottawa and the provinces.Under it,a Common Drug Review recommends to provincial lists which new drugs should be included.Predictably,and regrettably, Quebec refused to join.A few premiers are suspicious of any federal-provincial deal-making.They(particularly Quebec and Alberta) just want Ottawa to fork over additional billions with few,if any,strings attached.That’s one reason why the idea of a national list hasn’t gone anywhere,while drug costskeep rising fast.(44)_____________Premiers love to quote Mr.Romanow’s report selectively,especially the parts about more federal money. Perhaps they should read what he had to say about drugs:“A national drug agency would provide governments more influence on pharmaceutical companies in order to constrain the ever-increasing cost of drugs.”(45)_____________So when the premiers gather in Niagara Falls to assemble their usual complaint list,they should also get cracking about something in their jurisdiction that would help their budgets and patients.[A] Quebec’s resistance to a national agency is provincialist ideology. One of the first advocates for a national list was a researcher at Laval University. Quebec’s Drug Insurance Fund has seen its costs skyrocket with annual increases from 14.3 per cent to 26.8 per cent![ B] Or they could read Mr. Kirby’s report: “the substantial buying power of such an agency would strengthen the public prescription-drug insurance plans to negotiate the lowest possible purchase prices from drug companies.”C] What does “national” mean? Roy Romanow and Senator Michael Kirby recommended a federal-provincial body much like the recently created National Health Council.D] The problem is simple and stark: health-care costs have been, are, and will continue to increase faster than government revenues.E] According to the Canadian Institute for Health Information, prescription drug costs have risen since 1997 at [ [ [ twice the rate of overall health-care spending. Part of the increase comes from drugs being used to replace other kinds of treatments. Part of it arises from new drugs costing more than older kinds. Part of it is higher prices.[F] So, if the provinces want to run the health-care show, they should prove they can run it, starting with an interprovincial health list that would end duplication, save administrative costs, prevent one province from being played off against another, and bargain for better drug prices.[G] Of course, the pharmaceutical companies will scream. They like divided buyers; they can lobby better that way. They can use the threat of removing jobs from one province to another. They can hope that, if one provinceincludes a drug on its list, the pressure will cause others toinclude it on theirs. They wouldn’t like a national agency, but self-interest would lead them to deal with it.Part CDirections:Read the following text carefully and then translate the underlined segments into Chinese. Your translation should be written clearly on ANSWER SHEET 2. (10 points)It is not easy to talk about the role of the mass media in this overwhelmingly significant phase in European history. History and news become confused, and one’s impressions tend to be a mixture of skepticism and optimism. (46)Television is one of the means by which these feelings are created and conveyed —and perhaps never before has it served so much to connect different peoples and nations as in the recent events in Europe. The Europe that is now forming cannot be anything other than its peoples, their cultures and national identities. With this in mind we can begin to analyze the European television scene. (47) In Europe, as elsewhere, multi-media groups have been increasingly successful; groups which bring together television, radio, newspapers, magazines and publishing houses that work in relation to one another.One Italian example would be the Berlusconi group, while abroad Maxwell and Murdoch come to mind.Clearly, only the biggest and most flexible television companies are going to be able to compete in such a rich and hotly-contested market. (48) This alone demonstrates that the television business is not an easy world to survive in, a fact underlined by statistics that show that out of eighty European television networks, no less than 5 0% took a loss in 1989.Moreover, the integration of the European community will oblige television companies to cooperate more closely in terms of both production and distribution.(49)Creating a“European identity”that respects the different cultures and traditions which go to make up the connecting fabric of the Old Continent is no easy task and demands a strategic choice—that of producing programs in Europe for Europe.This entails reducing our dependence on the North American market,whose programs relate to experiences and cultural traditions which are different from our own.In order to achieve these objectives,we must concentrate more on co-productions,the exchange of news, documentary services and training.This also involves the agreements between European countries for thecreation of a European bank for Television Production which,on the model of the European Investments Bank,will handle the finances necessary for production costs.(50)In dealing with a challenge on such a scale,it is no exaggeration to say,“United we stand,divided we fall”—and if I had to choose a slogan it would be“Unity in our diversity.”A unity of objectives that nonetheless respect the varied peculiarities of each country.Section III WritingPart A51.Directions:Two months ago you got a job as an editor for the magazine Designs&Fashions.But now you find that the work is not what you expected.You decide to quit.Write a letter to your boss,Mr.Wang,telling him your decision,stating your reason(s),and making an apology.Write your letter with no less than100words.Write it neatly on ANSWER SHEET2.Do not sign your own name at the end of the letter;use“Li Ming”instead.You do not need to write the address.(10points)Part B52.Directions:Write an essay of160-200words based on the following drawing.In your essay,you should first describe the drawing,then interpret its meaning,and give your comment on it.You should write neatly on ANSWER SHEET2.(20points)2005年全国硕士研究生入学统一考试英语试题答案与解析Section I Use of English一、文章题材结构分析这是一篇科普性说明文，文章主要介绍了人类嗅觉的特点及原因。
2005年考研数学试题详解及评分参考介绍
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2005 年 • 第 3 页
郝海龙：考研数学复习大全·配套光盘·2005 年数学试题详解及评分参考
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2005 年 • 第 1 页
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郝海龙：考研数学复习大全·配套光盘·2005 年数学试题详解及评分参考
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2005年硕士研究生考试英语真题及答案
2005年硕士研究生考试英语真题及答案[ 作者: 转自: 浏览:883 ]【大小】【评论】【打印】【关闭】Section Ⅰ Use of EnglishDirections:Read the following text. Choose the best word(s) for each numb ered blank and mark A,B,C or D on ANSWER SHEET 1(10 points)The human nose is an underrated tool. Humans are often thought to be insensitive smellers compared with animals, 1 this is largely because, 2 animals ,we stand upright. This means that our noses are 3 to perceiving those smells which f loat through the air, 4 the majority of smells which stickto surfaces. In fact5 , we are extremely sensitive to smells,6 we do not g enerally realize it. Our noses are capable of7 human smells even when these are 8 to far below one part in one mill ion.Strangely, some people find that they can smell one type of flower but not another, 9 others are sensitive to the smells of both flowers. This may be because some people do not have the genes necessary to generate 10 smell receptors in the nose. These receptors are the cells which sense smells and send 11 to the brain. However, it has been found that evenpeople insensitive to a certain smell 12 can suddenly bec ome sensitive to it when 13 to it often enough.The explanation for insensitivity to smell seems to be that brain finds it14 to keep all smell receptors working all the time but can 15 new receptors if necessary. This may 16 explain why we are not usually sensitive to our own smells we simply donot need to be. We are not 17 of the usual smell of our own house but we 18 new smells when we visit someone else's. The brain finds it best to keep smell receptors 19 for unfamiliar and emergency signals 20 the smell of smoke, which might indicate the danger of fire.1. ［A］although ［B］as ［C］but ［D］while2. ［A］above ［B］unlike ［C］excluding ［D］besides3. ［A］limited ［B］committed ［C］dedicated ［D］confined4. ［A］catching ［B］ignoring ［C］missing ［D］tracking5. ［A］anyway ［B］though ［C］instead ［D］therefore6. ［A］even if ［B］if only ［C］only if ［D］as if7. ［A］distinguishing［B］discovering ［C］determining［D］detecti ng8. ［A］diluted ［B］dissolved ［C］determining［D］diffused9. ［A］when ［B］since ［C］for ［D］whereas10. ［A］unusual ［B］particular ［C］unique ［D］typical11. ［A］signs ［B］stimuli ［C］messages ［D］impulses12. ［A］at first ［B］at all ［C］at large ［D］at times13. ［A］subjected ［B］left ［C］drawn ［D］exposed14. ［A］ineffective ［B］incompetent ［C］inefficient［D］insuffici ent15. ［A］introduce ［B］summon ［C］trigger ［D］create16. ［A］still ［B］also ［C］otherwise ［D］nevertheless17. ［A］sure ［B］sick ［C］aware ［D］tired18. ［A］tolerate ［B］repel ［C］neglect ［D］notice19. ［A］availabe ［B］reliable［C］identifiable［D］suitable20. ［A］similar to［B］such as ［C］along with ［D］aside from Section ⅡReading ComprehensionPart ADirections:Read the following four texts. Answer the questions below each text b y choosing A,B,C or D. Mark your answers on ANSWER SHEET 1(4 0 points)Text 1Everybody loves a fat pay rise. Yet pleasure at your own can vanish i f you learn that a colleague has been given a bigger one. Indeed, if h e has a reputation for slacking, you might even be outraged. Such beh aviour is regarded as “all too human”, with the unde rlying assumption that other animals would not be capable of this finely developed sense of grievance. But a study by Sarah Brosnan and Frans de Waal of E mory University in Atlanta, Georgia, which has just been published in Nature, suggests that it all too monkey, as well.The researchers studied the behaviour of female brown capuchin mo nkeys. They look cute. They are good-natured, co-operative creatures, a nd they share their food tardily. Above all, like their female human co unterparts, they tend to pa y much closer attention to the value of “goo ds and services” than males. Such characteristics make them perfect ca ndidates for Dr. Brosnan's and Dr. de waal's; study. The researchers sp ent two years teaching their monkeys to exchange tokens for food. Nor mally, the monkeys were happy enough to exchange pieces of rock for slices of cucumber. However, when two monkeys were placed in sepa rate but adjoining chambers, so that each could observe what the otherwas getting in return for its rock, their became markedly different.In the world of capuchins grapes are luxury goods (and much prefe rable to cucumbers) So when one monkey was handed a grape in exch ange for her token, the second was reluctant to hand hers over for a mere piece of cucumber. And if one received a grape without having t o provide her token in exchange at all, the other either tossed her own token at the researcher or out of the chamber, or refused to ;accept t he slice of cucumber Indeed, the mere presence of a grape in the othe r chamber (without an actual monkey to eat it) was enough to reduce resentment in a female capuchin.The researches suggest that capuchin monkeys, like humans, are guid ed by social emotions, in the wild, they are a co-operative, groupliving species, Such co-operation is likely to be stable only when each anim al feels it is not being cheated. Feelings of righteous indignation, it se ems, are not the preserve of people alone, Refusing a lesser reward co mpletely makes these feelings abundantly clear to other members of th e group. However, whether such a sense of fairness evolved independe ntly in capuchins and humans, or whether it stems form the common a ncestor that the species had 35 million years ago, is, as yet, an unans wered question.21. In the opening paragraph, the author introduces his topic byA. posing a contrast.B. justifying an assumption.C. making a comparison.D. explaining a phenomenon.22. The statement “it is all too monkey” (Last line, paragraph l) impli es thatA. monkeys are also outraged by slack rivals.B. resenting unfairness is also monkeys' nature.C. monkeys, like humans, tend to be jealous of each other.D. no animals other than monkeys can develop such emotions.23.Female capuchin monkeys were chosen for the research most probab ly because they areA. more inclined to weigh what they get.B. attentive to researchers' ins tructions.C. nice in both appearance and temperament.D. more generous than the ir male companions24.Dr. Brosnan and Dr. de Waal have eventually found in their study t hat the monkeysA. prefer grapes to cucumbers.B. can be taught to exchange things.C. will not be co-operative if feeling cheated.D. are unhappy when sep arated from others.25. What can we infer from the last paragraph?A. Monkeys can be trained to develop social emotions.B. Human indignation evolved from an uncertain source.C. Animals usually show their feelings openly as humans do.D. Cooperation among monkeys remains stable only in the wild.Text 2Do you remember all those years when scientists argued that smoki ng would killus but the doubters insisted that we didn't know for sure? That the evi dence was inconclusive, the science uncertain? That the antismoking lo bby was out to destroy our way of life and the government should sta y out of the way? Lots of Americans bought that nonsense, and over t hree decades, some 10 million smokers went to early graves.There are upsetting parallels today, as scientists in one wave after an other try to awaken us to the growing threat of global warming. The l atest was a panel from the National Academy of Sciences, enlisted by the White House, to tell us that the Earth's atmosphere is definitely wa rming and that the problem is largely man-made. The clear message is that we should get moving to protect ourselves. The president of the National Academy, Bruce Alberts, added this key point in the preface to the panel's report “Science never has all the answers But science do es provide us with the best available guide to the future, and it is criti cal that out nation and the world base important policies on the best j udgments that science can provide concerning the future consequences of present actions.”Just as on smoking voices now come from many quarters insisting th at the science about global warming is incomplete, that it's Ok to keep pouring fumes into the air until we know for sure. this is a dangerou s game: by the 100 percent of the evidence is in, it may be too late. With the risks obvious and growing, a prudent people would take out an insurance policy now.Fortunately, the White House is starting to pay attention. But it's obv ious that a majority of the president's advisers still don't take global w arming seriously. Instead of a plan of action, they continue to press fo r more research-a classic case of “paralysis by analysis”.To serve as responsible stewards of the planet, we must press forwar d on deeper atmospheric and oceanic research But research alone is in adequate. If the Administration won't take the legislative initiative, Con gress should help to beginfashioning conservation measures A bill by Democratic Senator Robert Byrd of West Virginia, which would offer financial incentives for priva te industry is a promising start Many see that the country is getting re ady to build lots of new power plants to meet our energy needs. If w e are ever going to protect the atmosphere, it is crucial that those new plants be environmentally sound.26. An argument made by supporters of smoking was thatA. there was no scientific evidence of the correlation between smoking and death.B. the number of early deaths of smokers in the past decades was insi gnificant.C. people had the freedom to choose their own way of life.D. antismoking people were usually talking nonsense.27. According to Bruce Alberts, science can serve asA. a protector.B. a judge.C. a critic.D. a guide.28. What does the author mean by “paralysis by analysis” (Last line, paragraph 4)A. Endless studies kill action.B. Careful investigation reveals truth.C. prudent planning hinders.D. Extensive research helps decision-making.29. According to the author, what should the Administration do aboutA. Offer aid to build cleaner power plants.B. Raise public awareness o f conservation.C. Press for further scientific research.D. Take some legislative measur es.30. The author associates the issue of global warming with that of sm oking becauseA. they both suffered from the government's negligence.B. a lesson from the latter is applicable to the former.C. the outcome of the latter aggravates the former.D. both of them have turned from bad to worse.Text 3Of all the components of a good night's sleep, dreams seem to be le ast within our control. In dreams, a window opens into a world where logic is suspended and dead people speak. A century ago, Freud form ulated his revolutionary theory that dreams were the disguised shadows of our unconscious desires and rears, by the late 1970s. neurologists had switched to thinking of them as just “mental noise” the random b yproducts of the neural-repair work that goes on during sleep. Now res earchers suspect that dreams are part of the mind's emotional thermosta t, regulating moods while the brain is “off-line” And one leading autho rity says that these intensely powerful mental events can be not only h arnessed but actually brought under conscious control, to help us sleep and feel better, “It's your dream” says Rosalind Cartwright, chair of p sychology at Chicago's Medical Center. “If you don't like it , change i t.”Evidence from brain imaging supports this view. The brain is as acti ve during REM (rapid eye movement) sleep-when most vivid dreams o ccur-as it is when fully awake, says Dr, Eric Nofzinger at the University of Pittsburgh. But not all parts of the brain are equally involved, th e limbic system (the “emotional brain”)is especial ly active, while the p refrontal cortex (the center of intellect and reasoning) is relatively quie t. “We wake up from dreams happy of depressed, and those feelings c an stay with us all day” says Stanford sleep researcher Dr, William D ement.And this process need not be left to the unconscious. Cartwright beli eves one can exercise conscious control over recurring bad dreams As soon as you awaken, identify what is upsetting about the dream. Visua lize how you would like it to end instead, the next time is occurs, try to wake up just enough to control its course. With much practice peo ple can learn to, literally, do it in their sleep.At the end of the day, there's probably little reason to pay attention to our dreams at all unless they keep us from sleeping of “we wake u in a panic,” Cartwright says Terrorism, economic uncertainties and ge neral feelings of insecurity have increased people's anxiety. Those suffe ring from persistent nightmares should seek help from a therapist For t he rest of us, the brain has its ways of working through bad feelings. Sleep-or rather dream-on it and you'll feel better in the morning.31. Researchers have come to believe that dreamsA. can be modified in their courses.B. are susceptible to emotional cha nges.C. reflect our innermost desires and fears.D. are a random outcome of neural repairs.32. By referring to the limbic system, the author intends to showA. its function in our dreams.B. the mechanism of REM sleep.C. the relation of dreams to emotions.D. its difference from the prefro ntal cortex.33. The negative feelings generated during the day tend toA. aggravate in our unconscious mind.B. develop into happy dreams.C. persist till the time we fall asleep.D. show up in dreams early at ni ght.34.Cartwright seems to suggest thatA. waking up in time is essential to the ridding of bad dreams.B. visualizing bad dreams helps bring them under con troll.C. dreams should be left to their natural progression.D. dreaming may not entirely belong to the unconscious.35. What advice might Cartwright give to those who sometimes have had dreams?A. lead your life as usual.B. Seek professional help.C. Exercise conscious control.D. Avoid anxiety in the daytime.Text 4American no longer expect public figures, whether in speech or in w riting, to command the English language with skill and gift. Nor do th ey aspire to such command themselves. In his latest book, Doing Our Own Thing. The Degradation of language and Music and why we sho uld like, care, John McWhorter, a linguist and controversialist of mixed liberal and conservative views, sees the triumph of 1960scounter-culture as responsible for the decline of formal English.But the cult of the authentic and the personal, “doing our own thin g”, has spelt the death of formal speech, wr iting, poetry and music. W hile even the modestly educated sought an elevated tone when they pu t pen to paper before the 1960s, even the most well regarded writing since then has sought to capture spoken English on the page. Equally, in poetry, the highly personal, performative genre is the only form that could claim real liveliness. In both oral and written English, talking i s triumphing over speaking, spontaneity over craft.Illustrated with an entertaining array of examples from both high and low culture, the trend that Mr. McWhorter documents is unmistakable. But it is less clear, to take the question of his subtitle, why we shou ld, like care. As a linguist, he acknowledges that all varieties of huma n language, including non-standard ones like Black English, can be po werfully expressive-there exists no language or dialect in the world tha t cannot convey complex ideas He is not arguing, as many do, that w e can no longer think straight because we do not talk proper.Russians have a deep love for their own language and carry large c hunks of memorized poetry in their heads, while Italian politicians tend to elaborate speech that would seem old-fashioned to most English-sp eakers. Mr. McWhorter acknowledges that formal language is not strictl y necessary, and proposes no radical education reforms-he is really grie ving over the loss of something beautiful more than useful. We now t ake our English “on paper plates instead of china”. A shame, perhaps, but probably an inevitable one.36. According to Mc Whorter, the decline of formal EnglishA. is inevitable in radical education reforms.B. is but all too natural in language development.C. has caused the controversy over the counter-culture.D. brought about changes in public attitudes in the 1960s.37. The word “talking” (Linge6, paragraph3) denotesA. modesty.B. personality.C. liveliness.D. informality.38. To which of the following statements would Mc Whorter most like ly agree?A. Logical thinking is not necessarily related to the way we talk.B. Black English can be more expressive than standard English.C. Non-standard varieties of human language are just as entertaining.D. Of all the varieties, standard English Can best convey complex ideas.39. The description of Russians' love of memorizing poetry shows the author'sA. interest in their language.B. appreciation of their efforts.C. admiration for their memory.D. contempt for their old-fashionedness.40. According to the last paragraph, “paper plates” is to “china” asA. “temporary” is to “permanent”.B. “radical” is to “conservative”.C. “functional” is to “artistic”.D. “humble” is to “noble”.Part BDirections:In the following text, some sentences have removed. For Questions 41-45, choosethe most suitable one from the list A-G to fit into of the numbered bl ank thereare two extra choices, which do not fit in any of the gaps. Mark your answers onANSWER SHEET1. (10 points)Canada's premiers (the leaders of provincial governments), if they hav e any breath left after complaining about Ottawa at their late July ann ual meeting, might spare a moment to do something, to reduce health-care costs.They're all groaning about soaring health budgets, the fastest-growing component of which are pharmaceutical costs.41.What to do? Both the Romanow commission and the Kirby committee on health care-to say nothing of reports from other experts recommen ded the creation of a national drug agency. Instead of each province h aving its own list of approved drugs , bureaucracy, procedures and lim ited bargaining power, all would pool resources ,work with Ottawa, and create a national institution.42.But “national” doesn't have to mean that. “National” could mean interp rovincial-provinces combining efforts to create one body.Either way, one benefit of a “national” organization would be to neg otiate better prices, if possible, with drug manufacturers. Instead of hav ing one province-or a series of hospitals within a province-negotiate a price for a given drug on the provincial list, the national agency woul d negotiate on behalf of all provinces.Rather than, say, Quebec, negotiating on behalf of seven million peo ple, the national agency would negotiate on behalf 31 million people. Basic economics suggests the greater the potential consumers, the higher the likelihood of a better price.43.A small step has been taken in the direction of a national agency wi th the creation of the Canadian Co-ordinating Office for Health Techn ology Assessment, funded by Ottawa and the provinces. Under it, a Co mmon Drug Review recommends to provincial lists which new drugs s hould be included, predictably and regrettably Quebec refused to join.A few premiers are suspicious of any federal-provincial deal-making. They (particularly Quebec and Alberta) just want Ottawa to fork over additional billions with few, if any, strings attached. That's one reason why the idea of a nationalist hasn't gone anywhere while drug costs k eep rising fast.44.Premiers love to quote Mr. Romanow's report selectively, especially t he parts about more federal money perhaps they should read what he had to say a bout drugs.“A national drug agency would provide governments more influence on pharmaceutical companies in order to constrain the ever-increasing c ost of drugs.”45.So when the premiers gather in Niagara Falls to assemble their usual complaint list, they should also get cracking about something in their jurisdiction that would help their budgets and patients.A. Quebec's resistance to a national agency is provincialist ideology. O ne of the first advocates for a national list was a researcher at Laval University. Quebec's Drug Insurance Fund has seen its costs skyrocket with annual increases from 14.3 per cent to 26.8 per cent!B. Or they could read Mr. Kirby's report:“the substan tial buying power of such an agency would strengthen the public prescription-drug insur ance plans to negotiate the lowest possible purchase prices from drug companies”C. What does “national” mean? Roy Romanow and Senator Michael K irby recommended a federal-provincial body much like the recently cre ated National Health Council.D. The problem is simple and stark: health-care costs have been, are, and will continue to increase faster than government revenues.E. According to the Canadian Institute for Health Information. prescript ion drug costs have risen since 1997 at twice the rate of overall healt h-care spending. Part of the increase comes from drugs being used to replace other kinds of treatments part of it arises from new drugs costi ng more than older kinds. Part of it is higher prices.F. So, if the provinces want to run the health-care show, they should prove they can run it, starting with an interprovincial health list that w ould end duplication, save administrative costs, prevent one province fr om being played off against another, and bargain for better drug price s.G. Of course the pharmaceutical companies will scream. They like divi ded buyers, they can lobby better that way. They can use the threat of removing jobs from one province to another. They can hope that, if one province includes a drug on its, list the pressure will cause others to include it on theirs. They wouldn't like a national agency agency, but self-interest would lead them to deal with it.Part CDirections:Read the following text carefully and then translate the underlined seg ments into Chinese. Your translation should be written clearly on ANS WER SHEET2. (10points)It is not easy to talk about the role of the mass media in this overw helmingly significant phase in European history. History and news beco me confused, and one's impressions tend to be a mixture of skepticism and optimism. (46)Television is one of the means by which these feel ings are created and conveyed-and perhaps never before has it served t o much to connect different peoples and nations as is the recent event s in Europe .The Europe that is now forming cannot be anything other than its peoples, their cultures and national identities. With this in mi nd we can begin to analyze the European television scene. (47) In Eur ope, as elsewhere multi-media groups have been increasingly successful groups which bring together television, radio newspapers, magazines a nd publishing houses that work in relation to one another.One Italian e xample would be the Berlusconi group while abroad Maxwell and Mur doch come to mind.Clearly, only the biggest and most flexible television companies are going to be able to compete complete in such a rich and hotly-contes ted market. (48) This alone demonstrates that the television business is not an easy world to survive in a fact underlined by statistics that sh ow that out of eighty European television networks no less than 50% t ook a loss in 1989.Moreover, the integration of the European community will oblige tele vision companies to cooperate more closely in terms of both productio n and distribution.(49) Creating a “European identity” that respects the different cultures and traditions which go to make up the connecting fabric of the Old continent is no easy task and demands a strategic choice - that of producing programs in Europe for Europe. This entails reducing our depen dence on the North American market, whose programs relate to experie nces and cultural traditions which are different from our own.In order to achieve these objectives, we must concentrate more on co -productions, the exchange of news, documentary services and training. This also involves the agreements between European countries for the creation of a European bank will handle the finances necessary for pr oduction costs. (50) In dealing with a challenge on such a scale, it is no exaggeration to say “Unity we stand, divided we fall” -and if I ha d to choose a slogan it would be “Unity in our diversity.” A unity of objectives that nonetheless respect the varied peculiarities of each cou ntry.Section ⅢWritingPart A51. Directions:Two months ago you got a job as an editor for the magazine Design s & fashions. But now you find that the word is not what you expect ed. You decide to quit. Write a letter to your boss, Mr. Wang, telling him your decision stating your reason(s), and making an apology. Write your letter with no less than 100 words. Write it neatly on A NSWER SHEET2. Do not sign your own name at the end of the lette r, use “Li Ming” instead. You do not need to write the address. (10 p oints)Part B52. Directions:Write an essay of 160-200 words based on the following drawing. In your essay ,you should first describe the drawing the interpret its mea ning, and give your comment on it.You should write neatly on ANSWER SHEET2. (20 points)标准答案:Section I Use of English1-5 C B A C B 6-10 A D A D B11-15 C A D C D16-20 B C D A BSection II Reading ComprehensionPart A21-25 C B A C B 26-30 C D A D B31-35 A C D D A 36-40 B D A B CPart B41-45 E C G F BPart C46．电视是引发和传递这些感受的手段之一--在欧洲近来发生的事件中，它把不同的民族和国家连到一起，其作用之大，前所未有。
人类学考题
北京大学2005年人类学理论试题：一．名词解释（8*5=40）：1．格尔兹 2．文化霸权 3．差序格局 4．进化论 5．历史具体主义二．简答题（15*4=60）：1．英国功能学人类学与以前人类学的主要区别是什么？ 2．简述布朗的单系血统。
3．试述米德的《萨摩亚人的成年》大家庭与小孩子的关系。
4．简述马林诺夫斯基和布朗有关“功能”的不同解释。
三．论述题（25*2=50）：1．试述20世纪中国人类学史的基本演变线索。
2．试论礼物在社会建构中的作用。
2005年人类学方法试题：一．名词解释（8*5=40）：1．地方性知识 2．跨文化比较 3．文本 4．民族语言学 5．参与观察二．简答题（15*4=60）：1．试述人类学进化论的方法论。
2．试述历史材料在民族学中的价值。
3．说明海外民族志和家乡民族志在知识论上各有什么优点？ 4．简述主位方法的基本含义。
四．论述题（25*2=50）：1．Ethnography可以称为“田野志”吗？为什么？ 2．试述民族志方法应用于中国研究时遇到的问题？2004年人类学理论试题一名词解释10 *4社区后殖民主义结构人类学库拉圈二简述15*41.《忧郁的热带》中作者所宣称的人类学立场？2.简述《江村经济》在学术史上的地位3.人类区域关系档案的内容4.哈里斯的文化唯物论的内容三论述25*21.努尔人政治制度的基本特征2.米德《萨摩亚人的成年》的立论是什么？作者又是怎样证明的？2004年人类学方法试题一名词解释10 *41.年龄组制度2.人类学的整体观3.局内人观点4.家乡民族志二简述15*41.解释人类学的方法论特点2.民族中心主义持续存在的根源是什么3.人类学亲属符号表示联合家庭和多偶制家庭4.后现代人类学的基本特征三论述25*21.跨文化研究在人类学中的地位如何2.现代民族志的缺失何在2003年试题人类学理论一:概念解释1.涂尔干2.费孝通3.格尔茨4.传统5.社会结构6.象征人类学二:简述题1.简述博厄斯的人类学理论贡献2.简述新进化论3.简述结构人类学的基本观点4.简述列维-斯特劳斯的亲属关系的基本结构5.什么是文化相对论6.简述埃文思-普里查德的人类学观三:论述题1.举例论述人类学何以是文化批评2.论述经济全球化对没个民族文化的影响3.试论利奇的过程理论人类学方法一:概念解释1.民族志电影2.民族中心主义3.田野工作4.客位研究法5.拉的克里夫_布朗6.遗留物二:简述题1.简述实验民族志的基本特点2.简述仪式研究的社会人类学视角3.简述比较研究对人类学的意义4.简述参与观察所获资料与文献资料的几本差异5.什么是格尔茨解释人类学的“深描”6.简述本尼迪克特《文化模式》的研究方法三:论述题1.试论《努尔人》的方法论意义2.人类学的概念是这样建立的3.试论马林诺斯基《西太平洋的航海者》对人类学方法论的主要贡献2002年试题一. 概念解释1.进化论2.博厄斯3.米德4.结构主义5.利奇二. 简述题1.简述功能主义的基本观点2.简述宗教人类学的主要研究内容3.简述政治人类学的主要研究内容三. 论述题1.试述马林诺斯基的《文化论》的基本内容2.试述20世纪初期西方人类学的主要内容3.试述二战以后西方人类学的主要变化一. 概念解释1.田野工作2.民族志3.跨文化研究4.人类学5.民族中心主义二. 简述题1.简述社会人类学与历史学的差别2.你对人类学在中国"本土化"的看法3.试述人类学的基本研究规则三. 论述题1.试述一个人类学家研究自己民族和他民族时面临的主要困难和便利之处2.试述整体论3.试述归纳法在人类学研究中的意义2001年试题人类学理论一. 概念解释1.马林诺斯基2.新进化论3.文化相对论4.《江村经济》5.结构人类学6.社区研究法7.中华民族多元一体格局8.田野工作二. 简述题1试论功能主义和结构-功能主义的异同 2.试论50年代至70年代(二战后)英,法,美国人类学的基本变化情况 3.简述解释人类学的基本观点三. 论述题1.试从社会文化人类学分支领域(亲属制度,宗教人类学,经济人类学,政治人类学)之一论述本学科的研究特色2.举例说明民族志对于社会人类学的重要性3.略析人类学者在研究中国中面临的认识论挑战人类学方法一. 概念解释1.民族志2.参与观察3.跨文化比较研究4.“浓厚的描述”5.整体论二. 简述题1.简述社会人类学研究的方法论特征2.简述"主位法"和"客位法"的方法论差异三. 论述题1.试比较社会文化人类学研究中的共时方法和历时方法的结合2.论述经验事实与理论阐述之间的关系四.问答题1.《古代社会》的作者是( ) (1)泰勒(2)摩尔根(3)马林诺斯基2.结构人类学的代表人物是( ) (1)格尔茨(2)列维_斯特劳斯(30埃文思_普里查德3.弗里德曼是( ) (1)汉学人类学家(2)非洲人类学家(3)美洲印地安人类学家4田野工作是指( )(1)实地社会实习(2)地理学实地测量工作(3)民族志研究的核心过程(4)社会学的整体论方法上海大学一。
05级研究生复试考题 北交研究生考试
2005年硕士研究生入学考试试卷课程名称：电力电子技术（本试卷共有八道大题，满分为100分，考试时间为120分钟）一、填空题（10分，每题1分）1、某晶闸管若其断态重复峰值电压为500V，反向重复峰值电压为700V，则该晶闸管得额定电压为。
2、若流过晶闸管的电流有效值是157A，则其额定电流为。
（不考虑晶闸管的电流裕量）3、列四种电力电子器件中，属于半控型器件。
a. SCRb. GTOc. IGBTd. MOSFET。
4、三相三电平逆变器共有种工作状态。
？a. 8b. 9c. 16d. 275、获得SPWM波形的基本方法有：硬件生成法、和。
6、在采用SPWM控制的电压型逆变电路中，载波频率越高，则输出电压中的谐波频率越。
7、晶闸管交流调压电路的工作状态与负载性质。
a. 有关b. 无关8、在大电感负载可控整流电路中，换相压降ΔU d与控制角α。
a. 有关b. 无关9、可控整流电路，电阻性负载，当I d一定时，流过晶闸管的电流有效值I T随控制角α的增大而。
a. 增大b. 减小c. 不变10、下列功率器件中，最适合于小功率、高开关频率的变换器。
a. SCRb. IGBTc. MOSFETd. GTO二、判断题，正确的划“√”，不正确的划“×”（共20分，每题2分）（注意：本题共有10个小题。
每个小题后面有4个判断，答对4个判断得2分；答对3个判断得1.5分；答对2个判断得0.5分；其它不得分）1、电力电子器件的驱动电路通常采用的隔离技术有：①磁隔离（）②电容隔离（）③电感隔离（）④光藕隔离（）2、整流变压器漏抗对整流装置的影响有：①使整流装置的功率因数下降（）②使整流装置的输出电压下降（）③使整流装置中晶闸管上流过电流的di/dt下降（）④使电网电压波形中的谐波分量减小（）3、三相半波整流电路的特点有：①整流变压器存在直流磁化（）②可用于有源逆变（）③要求触发脉冲必须为宽脉冲或双窄脉冲（）④存在失控问题（）4、晶闸管有源逆变电路：①当某个晶闸管发生故障、失去开通能力时，肯定会导致逆变失败（）②不论什么原因导致逆变失败，其后果都会造成电流急剧增大（）③可以采用全控电路，也可以采用半控电路（）④交流侧可以与电网连接，也可以与负载连接（）5、Buck—Boost DC—DC变换器：①工作状态（连续或断续）是根据负载电流的情况定义的（）②在连续工作状态下，输入电流是连续的（）③传递能量的元件是电感（）④属于第一象限DC—DC变换器（）6、电压型无源逆变电路：①输出电压与负载性质无关（）②输出电流与负载性质无关（）③直流侧电流有脉动（）④上、下桥臂的控制需遵循“先断后开”的原则（）7、SPWM电压型逆变器采用同步调制，其特点有：①在调频过程中载波频率不变（）②在调频过程中载波比不变（）③低频运行时输出电压波形对称性好（）④低频运行时输出电压谐波分量较小（）8、单相晶闸管交流调压电路接电感性负载：①晶闸管通常采用宽脉冲触发（）②控制角α的移相范围是：0︒~180︒（）③当控制角α增大时，功率因数减小（）④当控制角α增大时，输出电压增大（）9、晶闸管交—交变频电路：①一般采用PWM方式工作（）②可四象限运行（）③与交—直—交变频电路相比输入侧功率因数较高（）④低频输出特性较好，适合于低速大功率交流调速系统（）10、PWM整流器：①可四象限运行（）②功率因数可接近于±1 （）③可用于电力牵引（）④可用于太阳能并网发电系统（）三、单相全控桥式整流电路，带电阻电感反电势负载，工作在有源逆变状态。
2005年硕士研究生入学考试及答案
目录1.05年北师大物理类各方向2.05年长光所3.05年东南大学4.05年中科大5.05年南京大学6.05年华中科大7.05年吉林大学（原子所）8.05年四川大学（原子与分子）9.05年北京理工10.05年河北理工11.05年长春理工北京师范大学2005年招收硕士研究生入学考试试题专业:物理类各专业科目代号:459研究方向:各方向考试科目:量子力学[注意]答案写在答题纸上，写在试题上无效。
1.(20分)一个电子被限制在一维谐振子势场中，活动范围求激发电子到第一激发态所需要的能量（用ev表示）（，，）提示：谐振子能量本征函数可以写成2.（30分）一个电子被限制在二维各向同性谐振子势场中（特征频率为）。
（1）写出其哈密顿量，利用一维谐振子能级公式找到此电子的能级公式和简并度。
（2）请推导电子的径向运动方程。
并讨论其在时的渐近解。
提示：极坐标下3．（50分）两个质量为的粒子，被禁闭在特征频率为的一维谐振子势场中，彼此无相互作用（此题中波函数无须写出具体形式）：（1）如果两个粒子无自旋可分辨，写出系统的基态（两个都在自己的基态）和第一激发能级（即一个在基态，另一个在第一激发态）的波函数和能量（注意简并情形）。
（10分）（2）如果两个粒子是不可分辨的无自旋波色子，写出系统的基态和第一激发态的能量和波函数。
如果粒子间互作用势为，计算基态能级到一级微扰项。
（15分）（3分）如果两个粒子是不可分辨的自旋1/2粒子，写出基态能级和波函数（考虑自旋）。
如果粒子间互作用能为，计算基态能量。
（15分）（4）同（3），解除势阱，两个粒子以左一右飞出。
有两个探测器分别（同时）测量它们的y方向自旋角动量。
请问测量结果为两电子自旋反向的几率是多少？（10分）4．（30分）中心力场中电子自旋与轨道角动量存在耦合能。
总角动量，是的共同本征态。
现有一电子处于态，且。
（1）在一基近似下，可用代替，请问电子的能量与态差多少？（2）请计算该电子产生的平均磁矩，并由此计算在z方向均匀磁场B中电子的能量改变多少？（），当，，当，5．（20分）一个定域（空间位置不动）的电子（自旋1/2）处于z方向强磁场中。
05年全国法律硕士专业学位研究生入学联考试题(综合课)
05年全国法律硕士专业学位研究生入学联考试题(综合课)05年全国法律硕士专业学位研究生入学联考试题(综合课)05年全国法律硕士专业学位研究生入学联考试题(综合课) 一、单项选择题：1 47小题，每小题1分，共47分。
下列每题给出的四个选项中，只有一项是符合试题要求的。
谓在答题卡上将所选项的字母涂黑。
1.关于法律的起源与演进的表述，能够成立的是（）。
a.古希腊斯多葛学派认为法律是民族精神的体现，随着民族的成长而成长b.法律的形成过程是法律日益脱离宗教、道德规范而成为独立的、专门的社会规范的过程c.社会公共事务的简化和人的独立意识的成长，也是促进法律的产生和发展的重要因素d.马克思主义法学认为，法的产生和发展是多种社会因素相互作用的产物，但这些因素又是在政治因素最终起决定作用的条件下相互作用的「答案」b.德国历史法学派（萨维尼）认为法律是民族精神的体现，随着民族的成长而成长。
古希腊斯多葛学派认为，理性作为一中遍及宇宙的普世力量，乃是法律和正义的基础。
因此选项a错误。
法律的起源是由与道德规范、宗教规范混为一体到相对独立的过程。
因此选项b正确。
促进法律的产生和发展的重要因素并非社会公共事务的简化，而是社会公共事务的复杂化。
据此，选项c错误。
马克思主义认为，在政治与经济的关系中，经济决定政治，政治从属于经济。
因此，选项d中政治因素最终起决定作用的说法是错误的。
2.关于资本主义法的表述，能够成立的是（）。
a.在封建社会中后期出现的带有资本主义因素的法律，在本质上已经属于真正意义上的资本主义法律了b.各国资产阶级国家政权的建立虽然在时间上有先有后，但其法律的产生却呈现出大致相同的特征c.维护资本主义私有制是资本主义法律始终不变的核心d.资本主义法与社会主义法相比，主要区别在于前者是公共意志的体现「答案」c.带有资本主义因素的法律，在本质不具有真正意义上的资本主义性质。
选项a错误。
各资产阶级国家的法律产生并不相同，资本主义法的产生在不同国家有不同形式和特点。
2005考研数学一真题及答案解析
2005年全国硕士研究生入学统一考试数学(一)试卷一、填空题(本题共6小题,每小题4分,满分24分.把答案填在题中横线上)(1)曲线122+=x x y 的斜渐近线方程为_____________.(2)微分方程x x y y x ln 2=+'满足91)1(-=y 的解为____________.(3)设函数181261),,(222z y x z y x u +++=,单位向量}1,1,1{31=n ,则)3,2,1(nu∂∂=.________.(4)设Ω是由锥面22y x z +=与半球面222y x R z --=围成的空间区域,∑是Ω的整个边界的外侧,则⎰⎰∑=++zdxdy ydzdx xdydz ____________.(5)设123,,ααα均为3维列向量,记矩阵123(,,)=A ααα,123123123(,24,39)=++++++B ααααααααα,如果1=A ,那么=B .(6)从数1,2,3,4中任取一个数,记为X ,再从X ,,2,1 中任取一个数,记为Y ,则}2{=Y P =____________.二、选择题(本题共8小题,每小题4分,满分32分.每小题给出的四个选项中,只有一项符合题目要求,把所选项前的字母填在题后的括号内)(7)设函数n n n x x f 31lim )(+=∞→,则()f x 在),(+∞-∞内(A)处处可导(B)恰有一个不可导点(C)恰有两个不可导点(D)至少有三个不可导点(8)设()F x 是连续函数()f x 的一个原函数,""N M ⇔表示"M 的充分必要条件是",N 则必有(A)()F x 是偶函数()f x ⇔是奇函数(B)()F x 是奇函数()f x ⇔是偶函数(C)()F x 是周期函数()f x ⇔是周期函数(D)()F x 是单调函数()f x ⇔是单调函数(9)设函数⎰+-+-++=yx y x dt t y x y x y x u )()()(),(ψϕϕ,其中函数ϕ具有二阶导数,ψ具有一阶导数,则必有(A)2222y u x u ∂∂-=∂∂(B)2222yu x u ∂∂=∂∂(C)222yuy x u ∂∂=∂∂∂(D)222xuy x u ∂∂=∂∂∂(10)设有三元方程ln e 1xz xy z y -+=,根据隐函数存在定理,存在点(0,1,1)的一个邻域,在此邻域内该方程(A)只能确定一个具有连续偏导数的隐函数(,)z z x y =(B)可确定两个具有连续偏导数的隐函数(,)x x y z =和(,)z z x y =(C)可确定两个具有连续偏导数的隐函数(,)y y x z =和(,)z z x y =(D)可确定两个具有连续偏导数的隐函数(,)x x y z =和(,)y y x z =(11)设21,λλ是矩阵A 的两个不同的特征值,对应的特征向量分别为12,αα,则1α,12()+A αα线性无关的充分必要条件是(A)01≠λ(B)02≠λ(C)01=λ(D)02=λ(12)设A 为(2)n n ≥阶可逆矩阵,交换A 的第1行与第2行得矩阵**.,B A B 分别为,A B 的伴随矩阵,则(A)交换*A 的第1列与第2列得*B (B)交换*A 的第1行与第2行得*B (C)交换*A 的第1列与第2列得*-B (D)交换*A 的第1行与第2行得*-B (13)设二维随机变量(,)X Y 的概率分布为XY 0100.4a1b0.1已知随机事件}0{=X 与}1{=+Y X 相互独立,则(A)0.2,0.3a b ==(B)0.4,0.1a b ==(C)0.3,0.2a b ==(D)0.1,0.4a b ==(14)设)2(,,,21≥n X X X n 为来自总体(0,1)N 的简单随机样本,X 为样本均值,2S 为样本方差,则(A))1,0(~N X n (B)22~()nS n χ(C))1(~)1(--n t SX n (D)2122(1)~(1,1)nii n X F n X=--∑三、解答题(本题共9小题,满分94分.解答应写出文字说明、证明过程或演算步骤)(15)(本题满分11分)设}0,0,2),{(22≥≥≤+=y x y x y x D ,]1[22y x ++表示不超过221y x ++的最大整数.计算二重积分⎰⎰++Ddxdy y x xy .]1[22(16)(本题满分12分)求幂级数∑∞=--+-121))12(11()1(n n n x n n 的收敛区间与和函数()f x .(17)(本题满分11分)如图,曲线C 的方程为()y f x =,点(3,2)是它的一个拐点,直线1l 与2l 分别是曲线C 在点(0,0)与(3,2)处的切线,其交点为(2,4).设函数()f x 具有三阶连续导数,计算定积分⎰'''+32.)()(dx x f x x(18)(本题满分12分)已知函数()f x 在[0,1]上连续,在(0,1)内可导,且(0)0,(1)1f f ==.证明:(1)存在),1,0(∈ξ使得ξξ-=1)(f .(2)存在两个不同的点)1,0(,∈ζη,使得.1)()(=''ζηf f(19)(本题满分12分)设函数)(y ϕ具有连续导数,在围绕原点的任意分段光滑简单闭曲线L 上,曲线积分24()22Ly dx xydyx yφ++⎰ 的值恒为同一常数.(1)证明:对右半平面0x >内的任意分段光滑简单闭曲线,C 有24()202Cy dx xydyx yφ+=+⎰.(2)求函数)(y ϕ的表达式.(20)(本题满分9分)已知二次型21232221321)1(22)1()1(),,(x x a x x a x a x x x f +++-+-=的秩为2.(1)求a 的值；(2)求正交变换x y =Q ,把),,(321x x x f 化成标准形.(3)求方程),,(321x x x f =0的解.(21)(本题满分9分)已知3阶矩阵A 的第一行是c b a c b a ,,),,,(不全为零,矩阵12324636k ⎡⎤⎢⎥=⎢⎥⎢⎥⎣⎦B (k 为常数),且=AB O ,求线性方程组0x =A 的通解.(22)(本题满分9分)设二维随机变量(,)X Y 的概率密度为(,)f x y =1001,02x y x <<<<其它求:(1)(,)X Y 的边缘概率密度)(),(y f x f Y X .(2)Y X Z -=2的概率密度).(z f Z(23)(本题满分9分)设)2(,,,21>n X X X n 为来自总体(0,1)N 的简单随机样本,X 为样本均值,记.,,2,1n i X X Y i i =-=求:(1)i Y 的方差n i DY i ,,2,1, =.(2)1Y 与n Y 的协方差1Cov(,).n Y Y2005年考研数学一真题解析一、填空题（本题共6小题，每小题4分，满分24分.把答案填在题中横线上）（1）曲线122+=x x y 的斜渐近线方程为.4121-=x y 【分析】本题属基本题型，直接用斜渐近线方程公式进行计算即可.【详解】因为a=212lim )(lim 22=+=∞→∞→x x x x x f x x ，[]41)12(2lim )(lim -=+-=-=∞→∞→x xax x f b x x ，于是所求斜渐近线方程为.4121-=x y （2）微分方程x x y y x ln 2=+'满足91)1(-=y 的解为.91ln 31x x x y -=.【分析】直接套用一阶线性微分方程)()(x Q y x P y =+'的通解公式：⎰+⎰⎰=-])([)()(C dx e x Q e y dx x P dx x P ，再由初始条件确定任意常数即可.【详解】原方程等价为x y x y ln 2=+'，于是通解为⎰⎰+⋅=+⎰⋅⎰=-]ln [1]ln [2222C xdx x x C dx e x e y dx x dx x =2191ln 31x C x x x +-，由91)1(-=y 得C=0，故所求解为.91ln 31x x x y -=（3）设函数181261),,(222z y x z y x u +++=，单位向量}1,1,1{31=n ，则)3,2,1(n u ∂∂=33.【分析】函数u(x,y,z)沿单位向量γβαcos ,cos ,{cos =n }的方向导数为：γβαcos cos cos z uy ux un u∂∂+∂∂+∂∂=∂∂因此，本题直接用上述公式即可.【详解】因为3x x u =∂∂，6y y u =∂∂，9z z u =∂∂，于是所求方向导数为)3,2,1(n u∂∂=.33313131313131=⋅+⋅+⋅（4）设Ω是由锥面22y x z +=与半球面222y x R z --=围成的空间区域，∑是Ω的整个边界的外侧，则⎰⎰∑=++zdxdy ydzdx xdydz 3)221(2R -π.【分析】本题∑是封闭曲面且取外侧，自然想到用高斯公式转化为三重积分，再用球面（或柱面）坐标进行计算即可.【详解】⎰⎰∑=++zdxdy ydzdx xdydz ⎰⎰⎰Ωdxdydz3=.)221(2sin 33200402R d d d R ⎰⎰⎰-=πππθϕϕρρ（5）设321,,ααα均为3维列向量，记矩阵),,(321ααα=A ，)93,42,(321321321ααααααααα++++++=B ，如果1=A ，那么=B 2.【分析】将B 写成用A 右乘另一矩阵的形式，再用方阵相乘的行列式性质进行计算即可.【详解】由题设，有)93,42,(321321321ααααααααα++++++=B =⎥⎥⎥⎦⎤⎢⎢⎢⎣⎡941321111),,(321ααα，于是有.221941321111=⨯=⋅=A B （6）从数1,2,3,4中任取一个数，记为X,再从X ,,2,1 中任取一个数，记为Y,则}2{=Y P =4813.【分析】本题涉及到两次随机试验，想到用全概率公式,且第一次试验的各种两两互不相容的结果即为完备事件组或样本空间的划分.【详解】}2{=Y P =}12{}1{===X Y P X P +}22{}2{===X Y P X P +}32{}3{===X Y P X P +}42{}4{===X Y P X P =.4813)4131210(41=+++⨯二、选择题（本题共8小题，每小题4分，满分32分.每小题给出的四个选项中，只有一项符合题目要求，把所选项前的字母填在题后的括号内）（7）设函数n n n x x f 31lim )(+=∞→，则f(x)在),(+∞-∞内(A)处处可导.(B)恰有一个不可导点.(C)恰有两个不可导点.(D)至少有三个不可导点.[C ]【分析】先求出f(x)的表达式，再讨论其可导情形.【详解】当1<x 时，11lim )(3=+=∞→n n n x x f ；当1=x 时，111lim )(=+=∞→n n x f ；当1>x 时，.)11(lim )(3133x x x x f n n n =+=∞→即.1,11,1,,1,)(33>≤≤--<⎪⎩⎪⎨⎧-=x x x x x x f 可见f(x)仅在x=1±时不可导，故应选(C).（8）设F(x)是连续函数f(x)的一个原函数，""N M ⇔表示“M 的充分必要条件是N”，则必有(A)F(x)是偶函数⇔f(x)是奇函数.（B ）F(x)是奇函数⇔f(x)是偶函数.(C)F(x)是周期函数⇔f(x)是周期函数.(D)F(x)是单调函数⇔f(x)是单调函数.[A ]【分析】本题可直接推证，但最简便的方法还是通过反例用排除法找到答案.【详解】方法一：任一原函数可表示为⎰+=xC dt t f x F 0)()(，且).()(x f x F ='当F(x)为偶函数时，有)()(x F x F =-，于是)()1()(x F x F '=-⋅-'，即)()(x f x f =--，也即)()(x f x f -=-，可见f(x)为奇函数；反过来，若f(x)为奇函数，则⎰x dt t f 0)(为偶函数，从而⎰+=xC dt t f x F 0)()(为偶函数，可见(A)为正确选项.方法二：令f(x)=1,则取F(x)=x+1,排除(B)、(C);令f(x)=x,则取F(x)=221x ,排除(D);故应选(A).（9）设函数⎰+-+-++=yx y x dt t y x y x y x u )()()(),(ψϕϕ,其中函数ϕ具有二阶导数，ψ具有一阶导数，则必有(A)2222y u x u ∂∂-=∂∂.（B ）2222y u xu ∂∂=∂∂.(C)222y u y x u ∂∂=∂∂∂.(D)222x u y x u ∂∂=∂∂∂.[B ]【分析】先分别求出22x u ∂∂、22yu ∂∂、y x u ∂∂∂2，再比较答案即可.【详解】因为)()()()(y x y x y x y x xu --++-'++'=∂∂ψψϕϕ，)()()()(y x y x y x y x yu -+++-'-+'=∂∂ψψϕϕ，于是)()()()(22y x y x y x y x xu -'-+'+-''++''=∂∂ψψϕϕ，)()()()(2y x y x y x y x yx u -'++'+-''-+''=∂∂∂ψψϕϕ，)()()()(22y x y x y x y x yu -'-+'+-''++''=∂∂ψψϕϕ，可见有2222y u xu ∂∂=∂∂，应选(B).（10）设有三元方程1ln =+-xz ey z xy ，根据隐函数存在定理，存在点(0,1,1)的一个邻域，在此邻域内该方程(A)只能确定一个具有连续偏导数的隐函数z=z(x,y).(B)可确定两个具有连续偏导数的隐函数x=x(y,z)和z=z(x,y).(C)可确定两个具有连续偏导数的隐函数y=y(x,z)和z=z(x,y).(D)可确定两个具有连续偏导数的隐函数x=x(y,z)和y=y(x,z).[D ]【分析】本题考查隐函数存在定理，只需令F(x,y,z)=1ln -+-xz e y z xy ,分别求出三个偏导数y x z F F F ,,，再考虑在点(0,1,1)处哪个偏导数不为0，则可确定相应的隐函数.【详解】令F(x,y,z)=1ln -+-xz e y z xy ,则z e y F xz x +='，yz x F y -='，x e y F xz z +-='ln ，且2)1,1,0(='x F ，1)1,1,0(-='y F ，0)1,1,0(='z F .由此可确定相应的隐函数x=x(y,z)和y=y(x,z).故应选(D).（11）设21,λλ是矩阵A 的两个不同的特征值，对应的特征向量分别为21,αα，则1α，)(21αα+A 线性无关的充分必要条件是(A)01≠λ.(B)02≠λ.(C)01=λ.(D)02=λ.[B ]【分析】讨论一组抽象向量的线性无关性，可用定义或转化为求其秩即可.【详解】方法一：令0)(21211=++αααA k k ，则022211211=++αλαλαk k k ，0)(2221121=++αλαλk k k .由于21,αα线性无关，于是有⎩⎨⎧==+.0,022121λλk k k 当02≠λ时，显然有0,021==k k ，此时1α，)(21αα+A 线性无关；反过来，若1α，)(21αα+A 线性无关，则必然有02≠λ(,否则，1α与)(21αα+A =11αλ线性相关)，故应选(B).方法二：由于⎥⎦⎤⎢⎣⎡=+=+21212211121101],[],[)](,[λλαααλαλααααA ，可见1α，)(21αα+A 线性无关的充要条件是.001221≠=λλλ故应选(B).（12）设A 为n （2≥n ）阶可逆矩阵，交换A 的第1行与第2行得矩阵B,**,B A 分别为A,B 的伴随矩阵，则(A)交换*A 的第1列与第2列得*B .(B)交换*A 的第1行与第2行得*B .(C)交换*A 的第1列与第2列得*B -.(D)交换*A 的第1行与第2行得*B -.[C ]【分析】本题考查初等变换的概念与初等矩阵的性质，只需利用初等变换与初等矩阵的关系以及伴随矩阵的性质进行分析即可.【详解】由题设，存在初等矩阵12E （交换n 阶单位矩阵的第1行与第2行所得），使得B A E =12，于是12*11212*12***12*)(E A E E A E A A E B -=⋅===-，即*12*B E A -=,可见应选(C).（13）设二维随机变量(X,Y)的概率分布为X Y 0100.4a1b 0.1已知随机事件}0{=X 与}1{=+Y X 相互独立，则(A)a=0.2,b=0.3(B)a=0.4,b=0.1(C)a=0.3,b=0.2(D)a=0.1,b=0.4[B ]【分析】首先所有概率求和为1，可得a+b=0.5,其次，利用事件的独立性又可得一等式，由此可确定a,b 的取值.【详解】由题设，知a+b=0.5又事件}0{=X 与}1{=+Y X 相互独立，于是有}1{}0{}1,0{=+===+=Y X P X P Y X X P ，即a=))(4.0(b a a ++,由此可解得a=0.4,b=0.1,故应选(B).（14）设)2(,,,21≥n X X X n 为来自总体N(0,1)的简单随机样本，X 为样本均值，2S为样本方差，则(A))1,0(~N X n (B)).(~22n nS χ(C))1(~)1(--n t S X n (D)).1,1(~)1(2221--∑=n F XX n n i i[D ]【分析】利用正态总体抽样分布的性质和2χ分布、t 分布及F 分布的定义进行讨论即可.【详解】由正态总体抽样分布的性质知，)1,0(~10N X n nX =-，可排除(A);又)1(~0-=-n t S X n n S X ，可排除(C);而)1(~)1(1)1(2222--=-n S n S n χ，不能断定(B)是正确选项.因为∑=-n i i n X X 222221)1(~),1(~χχ，且∑=-ni i n X X 222221)1(~)1(~χχ与相互独立，于是).1,1(~)1(1122212221--=-∑∑==n F X X n n X X n i in i i 故应选(D).三、解答题（本题共9小题，满分94分.解答应写出文字说明、证明过程或演算步骤.）（15）（本题满分11分）设}0,0,2),{(22≥≥≤+=y x y x y x D ，]1[22y x ++表示不超过221y x ++的最大整数.计算二重积分⎰⎰++D dxdy y xxy .]1[22【分析】首先应设法去掉取整函数符号，为此将积分区域分为两部分即可.【详解】令}0,0,10),{(221≥≥<+≤=y x y x y x D ，}0,0,21),{(222≥≥≤+≤=y x y x y x D .则⎰⎰++D dxdy y x xy ]1[22=⎰⎰⎰⎰+122D D xydxdy xydxdy dr r d dr r d ⎰⎰⎰⎰+=2021310320cos sin 2cos sin ππθθθθθθ=.834381=+（16）（本题满分12分）求幂级数∑∞=--+-121))12(11()1(n n n x n n 的收敛区间与和函数f(x).【分析】先求收敛半径，进而可确定收敛区间.而和函数可利用逐项求导得到.【详解】因为11)12()12()12)(1(1)12)(1(lim =+--⨯+++++∞→n n n n n n n n n ，所以当21x <时，原级数绝对收敛，当21x >时，原级数发散，因此原级数的收敛半径为1，收敛区间为（－1,1）记121(1)(),(1,1)2(21)n n n S x x x n n -∞=-=∈--∑，则1211(1)(),(1,1)21n n n S x x n -∞-=-'=∈--∑，122211()(1),(1,1)1n n n S x x x x ∞--=''=-=∈-+∑.由于(0)0,(0)0,S S '==所以2001()()arctan ,1x xS x S t dt dt x t '''===+⎰⎰2001()()arctan arctan ln(1).2x x S x S t dt tdt x x x '===-+⎰⎰又21221(1),(1,1),1n n n x x x x ∞-=-=∈-+∑从而22()2()1x f x S x x =++2222arctan ln(1),(1,1).1x x x x x x =-++∈-+（17）（本题满分11分）如图，曲线C 的方程为y=f(x)，点(3,2)是它的一个拐点，直线1l 与2l 分别是曲线C 在点(0,0)与(3,2)处的切线，其交点为(2,4).设函数f(x)具有三阶连续导数，计算定积分⎰'''+302.)()(dx x f x x 【分析】题设图形相当于已知f(x)在x=0的函数值与导数值，在x=3处的函数值及一阶、二阶导数值.【详解】由题设图形知，f(0)=0,2)0(='f ;f(3)=2,.0)3(,2)3(=''-='f f 由分部积分，知⎰⎰⎰+''-''+=''+='''+30303022302)12)(()()()()()()(dx x x f x f x x x f d x x dx x f x x =dx x f x f x x f d x ⎰⎰'+'+-='+-303030)(2)()12()()12(=.20)]0()3([216=-+f f （18）（本题满分12分）已知函数f(x)在[0，1]上连续，在(0,1)内可导，且f(0)=0,f(1)=1.证明：（I ）存在),1,0(∈ξ使得ξξ-=1)(f ；（II ）存在两个不同的点)1,0(,∈ζη，使得.1)()(=''ζηf f 【分析】第一部分显然用闭区间上连续函数的介值定理；第二部分为双介值问题，可考虑用拉格朗日中值定理，但应注意利用第一部分已得结论.【详解】（I ）令x x f x F +-=1)()(，则F(x)在[0，1]上连续，且F(0)=‐1<0,F(1)=1>0,应用零点定理，存在),1,0(∈ξ使得0)(=ξF ，即ξξ-=1)(f .（II ）在],0[ξ和]1,[ξ上对f(x)分别应用拉格朗日中值定理，知存在两个不同的点)1,(),,0(ξζξη∈∈，使得0)0()()(--='ξξηf f f ，ξξζ--='1)()1()(f f f 于是.1111)(1)()()(=-⋅-=--⋅=''ξξξξξξξξζηf f f f （19）（本题满分12分）设函数)(y ϕ具有连续导数，在围绕原点的任意分段光滑简单闭曲线L 上，曲线积分⎰++Ly x xydydx y 4222)(ϕ的值恒为同一常数.（I ）证明：对右半平面x>0内的任意分段光滑简单闭曲线C ，有022)(42=++⎰Cyx xydydx y ϕ；（II ）求函数)(y ϕ的表达式.【分析】证明（I ）的关键是如何将封闭曲线C 与围绕原点的任意分段光滑简单闭曲线相联系，这可利用曲线积分的可加性将C 进行分解讨论；而（II ）中求)(y ϕ的表达式，显然应用积分与路径无关即可.【详解】（I ）如图，将C 分解为：21l l C +=，另作一条曲线3l =++⎰Cy x xydydx y 4222)(ϕ-++⎰+314222)(l l y x xydydx y ϕ022)(3242=++⎰+l l y x xydydx y ϕ.（II ）设2424()2,22y xyP Q x yx yϕ==++，,P Q 在单连通区域0x >内具有一阶连续偏导数，由（Ⅰ）知，曲线积分24()22Ly dx xydyx y ϕ++⎰在该区域内与路径无关，故当0x >时，总有Q Px y∂∂=∂∂.24252422422(2)4242,(2)(2)Q y x y x xy x y y xx y x y ∂+--+==∂++ ①243243242242()(2)4()2()()4().(2)(2)P y x y y y x y y y y y y x y x y ϕϕϕϕϕ'''∂+-+-==∂++②比较①、②两式的右端，得435()2,()4()2. y y y y y y y ϕϕϕ'=-⎧⎨'-=⎩由③得2()y y c ϕ=-+，将()y ϕ代入④得535242,y cy y -=所以0c =，从而2().y y ϕ=-（20）（本题满分9分）已知二次型21232221321)1(22)1()1(),,(x x a x x a x a x x x f +++-+-=的秩为2.（I ）求a 的值；（II ）求正交变换Qy x =，把),,(321x x x f 化成标准形；（III ）求方程),,(321x x x f =0的解.【分析】（I ）根据二次型的秩为2，可知对应矩阵的行列式为0，从而可求a 的值；（II ）是常规问题，先求出特征值、特征向量，再正交化、单位化即可找到所需正交变换；（III ）利用第二步的结果，通过标准形求解即可.【详解】（I ）二次型对应矩阵为⎥⎥⎥⎦⎤⎢⎢⎢⎣⎡-++-=200011011a a a a A ，由二次型的秩为2，知0200011011=-++-=a a a a A ，得a=0.（II ）这里⎥⎥⎥⎦⎤⎢⎢⎢⎣⎡=200011011A ，可求出其特征值为0,2321===λλλ.解0)2(=-x A E ，得特征向量为：⎪⎪⎪⎭⎫⎝⎛=⎪⎪⎪⎭⎫ ⎝⎛=100,01121αα，解0)0(=-x A E ，得特征向量为：.0113⎪⎪⎪⎭⎫ ⎝⎛-=α由于21,αα已经正交，直接将21,αα，3α单位化，得：③④⎪⎪⎪⎭⎫⎝⎛-=⎪⎪⎪⎭⎫ ⎝⎛=⎪⎪⎪⎭⎫ ⎝⎛=01121,100,01121321ηηη令[]321ααα=Q ，即为所求的正交变换矩阵，由x=Qy ，可化原二次型为标准形：),,(321x x x f =.222221y y +（III ）由),,(321x x x f ==+222122y y 0，得k y y y ===321,0,0（k 为任意常数）.从而所求解为：x=Qy=[]⎥⎥⎥⎦⎤⎢⎢⎢⎣⎡-==⎥⎥⎥⎦⎤⎢⎢⎢⎣⎡0003321c c k k ηηηη，其中c 为任意常数.（21）（本题满分9分）已知3阶矩阵A 的第一行是c b a c b a ,,),,,(不全为零，矩阵⎥⎥⎥⎦⎤⎢⎢⎢⎣⎡=k B 63642321（k 为常数），且AB=O,求线性方程组Ax=0的通解.【分析】AB=O,相当于告之B 的每一列均为Ax=0的解，关键问题是Ax=0的基础解系所含解向量的个数为多少，而这又转化为确定系数矩阵A 的秩.【详解】由AB=O 知，B 的每一列均为Ax=0的解，且.3)()(≤+B r A r （1）若k 9≠,则r(B)=2,于是r(A)1≤,显然r(A)1≥,故r(A)=1.可见此时Ax=0的基础解系所含解向量的个数为3‐r(A)=2,矩阵B 的第一、第三列线性无关，可作为其基础解系，故Ax=0的通解为：2121,,63321k k k k k x ⎪⎪⎪⎭⎫ ⎝⎛+⎪⎪⎪⎭⎫ ⎝⎛=为任意常数.(2)若k=9，则r(B)=1,从而.2)(1≤≤A r 1）若r(A)=2,则Ax=0的通解为：11,321k k x ⎪⎪⎪⎭⎫⎝⎛=为任意常数.2）若r(A)=1,则Ax=0的同解方程组为：0321=++cx bx ax ,不妨设0≠a ,则其通解为2121,,1001k k a c k a b k x ⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-+⎪⎪⎪⎪⎪⎭⎫ ⎝⎛-=为任意常数.（22）（本题满分9分）设二维随机变量(X,Y)的概率密度为.,20,10,0,1),(其他x y x y x f <<<<⎩⎨⎧=求：（I ）(X,Y)的边缘概率密度)(),(y f x f Y X ；（II ）Y X Z -=2的概率密度).(z f Z 【分析】求边缘概率密度直接用公式即可；而求二维随机变量函数的概率密度，一般用分布函数法，即先用定义求出分布函数，再求导得到相应的概率密度.【详解】（I ）关于X 的边缘概率密度)(x f X =⎰+∞∞-dy y x f ),(=.,10,0,20其他<<⎪⎩⎪⎨⎧⎰x dy x =.,10,0,2其他<<⎩⎨⎧x x 关于Y 的边缘概率密度)(y f Y =⎰+∞∞-dx y x f ),(=.,20,0,12其他<<⎪⎩⎪⎨⎧⎰y dx y=.,20,0,21其他<<⎪⎩⎪⎨⎧-y y （II ）令}2{}{)(z Y X P z Z P z F Z ≤-=≤=，1）当0<z 时，0}2{)(=≤-=z Y X P z F Z ；2）当20<≤z 时，}2{)(z Y X P z F Z ≤-==241z z -;3)当2≥z 时，.1}2{)(=≤-=z Y X P z F Z 即分布函数为：.2,20,0,1,41,0)(2≥<≤<⎪⎩⎪⎨⎧-=z z z z z z F Z 故所求的概率密度为：.,20,0,211)(其他<<⎪⎩⎪⎨⎧-=z z z f Z （23）（本题满分9分）设)2(,,,21>n X X X n 为来自总体N(0,1)的简单随机样本，X 为样本均值，记.,,2,1,n i X X Y i i =-=求：（I ）i Y 的方差n i DY i ,,2,1, =；（II ）1Y 与n Y 的协方差).,(1n Y Y Cov 【分析】先将i Y 表示为相互独立的随机变量求和，再用方差的性质进行计算即可；求1Y 与n Y 的协方差),(1n Y Y Cov ，本质上还是数学期望的计算，同样应注意利用数学期望的运算性质.【详解】由题设，知)2(,,,21>n X X X n 相互独立，且),,2,1(1,0n i DX EX i i ===，.0=X E （I ）∑≠--=-=nij j i i i X n X n D X X D DY ]111[()(=∑≠+-nij ji DXnDX n 22111(=.1)1(1)1(222n n n n n n -=-⋅+-（II ）)])([(),(111n n n EY Y EY Y E Y Y Cov --==)])([()(11X X X X E Y Y E n n --==)(211X X X X X X X E n n +--=211(2)(XE X X E X X E n +-=22121)(][20X E X D X X X E n nj j +++-∑==.112nn n -=+-。
2005考研英语真题答案解析课件.doc
2005 年全国硕士研究生入学统一考试英语试题答案Section I Use of English(10 points)1-5. CBACB 6-10. ADADB 11-15. CADCD 16-20. BCDABSection II Reading Comprehension(60 points)Part A (40 points) 21-25. CBACB 26-30. CDADB 31-35. ACDDA 36-40. BDABCPart B (10 points) 41-45. ECGFBPart C (10 points)46. 电视是创造和传递感情的手段之一。
也许在此之前，就加强不同的民族和国家之间的联系而言，电视还从来没有像在最近的欧洲事件中起过如此大的作用。
47. 多媒体集团在欧洲就像在其他地方一样越来越成功了。
这些集团把相互关系密切的电视台、电台、报纸、杂志、出版社整合到了一起。
48. 仅这一点就表明在电视行业不是一个容易生存的领域。
这个事实通过统计数字一目了然，统计表明在80 家欧洲电视网中1989 年出现亏损的不少于50%。
49. 创造一个尊重不同文化和传统的“欧洲统一体”绝非易事，需要战略性选择。
正是这些文化和传统组成了连接欧洲大陆的纽带。
50. 在应付一个如此规模的挑战过程中，我们可以毫不夸张地说，“团结，我们就会站起来；分裂，我们就会倒下去。
”Section ⅢWriting (30 points)Part A (10 points) A Letter, to QuitJun 22, 2005 Dear Mr. Wang,First of all, please allow me to express my deep sorry to you for my resignation. I do know that this will bring about much trouble to you so that I write to you for my explanation.I decided to quit for some reasons as follows. To begin with, the job as an editor for the magazine Designs & Fashions is not suitable to me. What ’s more, I ’mpreparindegree and I prefer to further my study. Again, I apologize for my resignation to you!I am looking forward to your early reply.Yours Sincerely,Li MingPart B (20 points)A Helpless FatherThe picture ironically shows that a pitiable old man in rags is being helplessly kicked off by his three sons and a daughter,who all wear decent clothes. The father ’s negligent ch are all guarding their home gates lest their old father “roll into ”their households. In other words, they four ignore their m o t r h a e l s r e n s p s e o n o s f i b a i s l i s t y u m f o i r n t g h e i r old father eventhough they may be all living a satisfying life. That is a painful scene we often encounter in our daily life.Sad to say, the moral decline of the younger generations may be a rather explosive situation in our modern society. People definitely have their living conditions improved by wider and wider margins, as evidenced by the four children ’s decent dressing, but their moral sense still remains sadly unchanged or in some cases becomes dramatically d o w n g r.a M d i o n s g t peoplemight have become too much self-centered, and even worse, they discard the tradition of giving respect to the elderly. They no longer care for their elders, let alone their neighbors or the disadvantaged; instead they try every means to avoid responsibility for other citizens. When one cares for others, one might even appear stupid or may even be distrusted.Therefore, we have to take some useful measures to avoid the scene that is mentioned above. We must launch a variety of campaigns about the return to the good tradition of giving help and love the elderly. Moreover, we must appeal to our government to establish some relevant laws to punish those who avoid their duties. The last but not the least, our respect for age is an indication of the progress of human society, as imperatives of traditions require. We sincerely wish that the old man could be welcome to any of the four households, elegantly dressed, anda smile on the face.2005 年全国硕士研究生入学统一考试英语(一)试题答案详解Section I Use of English1. C 空格前讲的是，和动物相比，人的嗅觉常被认为不灵敏，空格后讲的是，⋯这主要是因为，⋯动物，我们是直立的。
2005年研究生入学考试数学二模拟试题参考答案 .doc
本人提供的文档均由本人编辑如成，如对你有帮助，请下载支持！2005年研究生入学考试数学二模拟试题参考答案一、填空题（本题共6小题，每小题4分，满分24分. 把答案填在题中横线上（1）[解] 2000011ln(1)1111limlimlim (ln(1)1)lim 2(1)22x x x x x x xx x x x x xxxI e eeee →→→→--+-++--+=====.（2）[解] 222111000011|(1)22y y y y I e dy dx ye dy e e ====-⎰⎰⎰. （3）[解] cos (1cos )cos sin (1cos )sin x x a y y a ρθθθρθθθ==+⎧⎧⇒⎨⎨==+⎩⎩. 2sin (1cos )cos cos cos 23cot sin cos (1cos )sin sin sin 22dydy a a d dx dx a a d θθθθθθθθθθθθθθ-+++===-=---++. （4）[解] 将,θϕ看作,x y 的隐函数，于是，由sin cos x R θϕ=，sin sin y R θϕ=，对x求偏导.得：1cos cos sin (sin )0cos sin sin cos R R x xR R x x θϕθϕθϕθϕθϕθϕ∂∂⎧=+-⎪⎪∂∂⎨∂∂⎪=+⎪∂∂⎩. 用克莱姆法则解出cos cos x R θϕθ∂=∂. 另解：2222sin x y R θ+=，两边对x 求偏导， 得： 222s i nc o s x R x θθθ∂=∂，即 2sin cos sin cos R R xθθϕθθ∂=∂. 得：c o s c o s x R θϕθ∂=∂. 同理，可得：cos sin y R ϕϕθ∂=∂.本人提供的文档均由本人编辑如成，如对你有帮助，请下载支持！（5） [解] 110220211111limarctan 2|arctan 2212221()nn k dx I x k nx n→∞==⋅===++∑⎰. （6）[解] 由题设，()()3,() 1 () 2 ||0P A P B P B P A A +≤≥⇒≤⇒=.843862805t t t ⇒-+++--=⇒=.二、选择题（本题共8小题，每小题4分，满分32分，每小题给出四个选项中，只有一项符合题目要求，把所选项前的字母填在题后的括号内）（7）[解] 要使()f x 在0x =处连续，必须使2222022000sin sin 2sin limlim lim 12x x x x t x dt x x t x k x x x→→→⋅====⎰. 选（B ）.（8） [解]22cos 1cos dydydydy dt dt t dxdx dt dtt===. 22222222(cos )(cos )(2sin cos cos )cos d y d dy d dy dt dy d y t t t t t t dx dx dt dt dt dx dt dt===-+⋅ 2422cos sin 2cos d y dyt t t dt dt=-. 选（D ）.（9）[解] ln yy x x e =⇒=，故ln ln by aS e dy =⎰.x题9本人提供的文档均由本人编辑如成，如对你有帮助，请下载支持！（10）[解] ()2()()10f x f x f x '''--=. 令0x x =，0()0f x '=，0()10f x ''∴=>. 选（B ）.（11）[解] 52424211111()()()||25xxxx t g x x x g t tdt t dt g t ''⋅=⇒=⇒=⎰⎰.令2x =，得132167((4)(1)) (4)2555g g g -=-⇒=. 选（C ）. （12）[解] 2(25)1sin 2D D y x -+=+.*2111(1sin 2)sin 225512y x x D D D =+=+-+-211211sin 2(sin 24cos 2)514517D x x x D +=+=++-. 选（D ）. （13）[解] 由题设，特征值λ：23,,1.3-- 2||(3)()123A =-⨯-⨯=. *35A E +的特征值为||35A λ+：23()533⋅+=-，23()5423⋅+=--，23()5111⋅+=.故 *|35|3(4)11132A E +=⨯-⨯=-. 选（D ）.（14）[解] 由题设，()ij m n A a ⨯=，()R A r =. 选（A ）. 三、解答题（本题共9小题，满分94分，解答应写出文字说明、证明过程或演算步骤）（15）（本题满分10分）本人提供的文档均由本人编辑如成，如对你有帮助，请下载支持！[解]2222200011sinsin 1lim lim lim sin 0sin x x x x x x x x x x x→→→===.0001113ln(3)ln(2)lim()limln()lim12sin sin 2303lim()2xxx xx x x e e e x xxxx x x ex e eee e x→→→----+--++-→-====+1I e -∴=.（16）（本题满分10分）[解] 令1x y ==，由()()() (1)(1)(1) (1)0f xy yf x f y f f f f =+⇒=+⇒=.0()()[(1)]()()limlim y y f x xy f x f x y f x f x xy xy →→+-+-'== 0(1)(1)()()limy f y y f x f x xy→+++-=0(1)(1)()(1)()lim y f y f yf x f f x xy xy x x →'⎡⎤+-=+=+⎢⎥⎣⎦ (1)1f '=，()1()f x f x x x'∴=+ （*） ①()()() ln ()ln ln ()()f x df x dxf x f x x c f x cx x f x x'=⇒=⇒=+⇒=. ②令()()f x c x x =为（*）的解，将其代入并整理，得： 1()c x x x '=，21()c x c x=-+. 故 221()()1f x c x c x x=-+=-+. 令1x =，得：2201 1c c =-+⇒=. 故 ()1f x x =-+.本人提供的文档均由本人编辑如成，如对你有帮助，请下载支持！（17）（本题满分11分） [解] 设对12x x <，12,(,)x x a b ∈，12()()0f x f x ==.用反证法.若()g x 在12(,)x x 内恒不为0，令()()()f x F xg x =， ()()()()0f x g x f x g x ''-≠在(,)a b 内成立，又12()()0f x f x ==，12(),()g x g x ∴必不为0.于是，()F x 在12[,]x x 上连续，在12(,)x x 内可导，且12()()0F x F x ==. 由洛尔定理，∃一个12(,)x x ξ∈，使2()()()()()0()f g f g F g ξξξξξξ''-'==.与()()()()0f g f g ξξξξ''-≠矛盾. 命题得证.（18）（本题满分12分）[证明] ①00()()2()xxF x xf t dt tf t dt =-⎰⎰0()()2()x xF x x f t dt tf t dt ---=--⎰⎰()()2()()()xxu t x f u d u u f u d u =--------⎰⎰令 0()2()xxx f t dt tf t dt =---⎰⎰() ()2()()x xf x x f t dt tf t dt F x -=⎰⎰为偶函数.故()f x 为偶函数.②0()()()2()xF x f t dt xf x xf x '=+-⎰()()xf t dt xf x =-⎰(0,) ()()[()()]x xf xf x x f f x ξξξ∃∈-=-由积分中值定理，.当0x >时，0x ξ≤≤，由()f x 非增，()() ()0f f x F x ξ'≥⇒≥；本人提供的文档均由本人编辑如成，如对你有帮助，请下载支持！ 当0x <时，0x ξ≤≤，由()f x 非增，()() ()0f f x F x ξ'≤⇒≥； 当0x =时，()0F x '=.综上所述，()0F x '≥. 故()F x 非减.（19）（本题满分12分） [解] [(),()]vuZ f x y xh y ϕ=-，()()u v Zf x f h y xϕ∂'''=⋅+⋅∂. 2(()())u v Z x f h y f x y yϕ∂∂'''=⋅+⋅∂∂∂ 22()[(1)()]()()[(1)()]uvv vu u v x f f xh y h y f h y f f xh y ϕ'''''''''''''=⋅-+⋅+⋅+⋅-+⋅22()[()()()]()()()uvv u v x f x x h y h y f xh y h y f h y f ϕϕ''''''''''''=-+-++. (1)()u v Zf f xh y y∂'''=⋅-+⋅∂. 22[()]u v Z f xh y f y y∂∂'''=-+∂∂ 22[(1)()]()()[(1)()]uvv vu u v f f xh y xh y f xh y f f xh y ''''''''''''''=--+⋅++-+⋅ 22222()()()uvv u v f xh y f x h y f xh y f '''''''''''=-++.（20）（本题满分11分）[解] ()()()()()xaaxg x x t f t dt t x f t dt -=-+-⎰⎰()()()()xxaaaaxxx f t dt tf t dt tf t dt x f t dt --=-+-⎰⎰⎰⎰.本人提供的文档均由本人编辑如成，如对你有帮助，请下载支持！ ①()()()()()()()()()x a x aaxaxg x f t dt xf x xf x xf x f t dt xf x f t dt f t dt --'=+---+=-⎰⎰⎰⎰.()()()2()0g x f x f x f x ''=+=>.故()g x '单调增大. ②令()0 0g x x '=⇒=. ③0220(0)||()() 1 ()()()()1aaaag t f t dt f a a t f t dt tf t dt f a a --==--⇒-+=--⎰⎰⎰. （*）两边对a 求导，得：()()()2af a af a f a a '-+=-.()()f t f t -=2()2()()2 2 ln[()1]()1f a af a f a a a f a a c f a ''∴=-⇒=⇒+=++.由（*）可知(0)1f =，代入上式，得：ln 2c =. 故222ln2()12 ()21aa t f a e e f t e ++==⇒=-.（21）（本题满分10分）解：由以上分析可得：1 dhc h ct c dt =⇒=+，0,0t h ==，10c ⇒=.于是h ct =. 代入dx k dt h =，得：dx A dt t =（k A c=常数）ln x A t B ⇒=+（B 为任意常数）.将t T =时，0x =；1t T =+时，2x =；2t T =+时，3x =代入，得： l n 0A TB += ① ln(1)2A T B ++= ② ln(2)3A T B ++= ③本人提供的文档均由本人编辑如成，如对你有帮助，请下载支持！ ②-①T+1Aln2T ⇒=，③-②2ln 11T A T +⇒=+，22121() 10 3712T T T T T T T ++⇒=⇒+-=⇒=≈+（分）. 下雪从上午7点23分开始.（22）（本题满分9分）[解] ①设Ax x λ=，0x ≠.λ为A 的特征值，则有kkA x x λ=.0 0 0k k A x λλ=⇒=⇒=.而()(1)A E x Ax Ex x x x x λλ+=+=+=+=.（0λ=）可知，A E +得特征值全为1.故||1A E +=.②用反证法.若A 可对角化，则存在可逆阵P ，使1P AP -=Λ，其中Λ是由A 的特征值构成的对角阵，即0Λ=.从而0A ⇒=.与0A ≠矛盾.这说明A 不能对角化.（23）（本题满分9分）[解] 由题设可知(1,1,0,2)T -为Ax β=的特解.(1,1,2,0)T-为0Ax =的基础解系，且可知向量组1234,,,,ααααβ的秩为3.①设β可由123,,ααα线性表示，则有11223340k k k βαααα=+++，即123(,,,0)Tk k k 为Ax β=的解.于是，123123(,,,0)(1,1,0,2)(1,1,,2)T T Tk k k k k k --=+--是0Ax=的解.故它可由(1,1,2,0)T -线性表示.而123(1,1,,2)T k k k +--与(1,1,2,0)T -线性无关，矛盾.故β不能由123,,ααα线性表示.②(1,1,2,0)T-是方程组0Ax =的解，123120 αααα∴-+=⇒可由234,,ααα线性表示. 又β可由1234,,,αααα线性表示，所以又β可由234,,ααα线性表示.又向量组1234,,,,ααααβ的秩为3，故234,,ααα是向量组1234,,,,ααααβ的一个极大无关组.。
2005年全国部分高校研究生数学建模竞赛B题
2005年全国部分高校研究生数学建模竞赛B 题空 中 加 油对飞行中的飞机进行空中加油，可以大大提高飞机的直航能力。
为了简化问题，便于讨论，我们作如下假设。
设A 为空军基地，基地有一架作战飞机（简称主机）和n 架加油机（简称辅机）。
主机与辅机的速度和单位时间的耗油量均相同且为常数，油箱装满油后的最大航程均为L （公里）。
辅机可以对主机加油，辅机之间也可以相互加油。
今主机要执行某作战任务（如侦察或空投），所有飞机在完成自身的任务后均要求返回基地。
主机的最大作战半径（简称作战半径）是指主机在n 架辅机的协助下所能飞到的（并安全返回）离基地A 的最远距离。
显然当0=n 时，作战半径2/0L r =。
问题1 设飞机垂直起飞、垂直降落、空中转向、在地面或空中加油的耗时均忽略不计，每架飞机只能上天一次，在上述假设下的作战半径记为n r 。
当4,3,2,1=n 时，求作战半径n r 。
问题2 在问题1的假设下，当4>n 时，尽你的可能求出n r （提示：先假设辅机可以分为两类，第一类专为主机前进服务，第二类专为主机返回服务，再考虑一般情形），或给出n r 的上、下界； 讨论当∞→n 的过程中n r 与n 的渐近关系； 试给出判断最优作战方案（主机能够飞到n r 处）的必要条件或充分条件。
问题3 若每架辅机可以多次上天，辅机从机场上空降落及在地面检修、加油、再起飞到机场上空的时间相当于飞行12/L 的时间，飞机第一次起飞、转向、在空中加油的耗时仍忽略不计，此时的作战半径记为n R ，讨论与问题1、问题2类似的问题。
问题4 若另有2个待建的空军基地（或航空母舰）21,A A ，有n 架辅机，主机从基地A 起飞，向一给定的方向飞行，必须在基地A 降落，辅机可在任一基地待命，可多次起飞，且可在任一基地降落。
其他同问题3的假设，讨论21,A A 的选址和主机的作战半径*n R 。
问题5 设ABCD 为矩形，L AB 4=，L AD 2=，D B A ,,为三个空军基地，主机从A 起飞，到C 执行任务（执行任务时间仍忽略不计）再返回A 。
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北京邮电大学2005年硕士研究生入学考试试题
考试科目：信号与系统（B ）
请考生注意：所有答案（包括选择题和填空题）一律写在答题纸上，写清题号，否则不计成绩。
计算题要算出具体答案，可以用计算器，但不能互相借用。
1. （8分）已知()t f 25−的波形如图1所示，画出()t f 的波形。
图1
2. （5分）某连续系统的框图如图2所示，写出该系统的微分方程。
f
图2
3. （7分）已知()t f 1和()t
f 2的波形如图3所示，试分段写出卷积
()
()()t f t f t f 21∗=的表达式，并画出()t f 波形
图3
4. （5分）计算卷积和：()()()n h n x n y ∗=，其中()()()2−−=n u n u n x ，
()()n u n h n
=41。
5. （5分）系统1是一个()()()t u e t t h t −−=δ1的高通RC 电路，系统2是一个
()()t u e t h t −=2的低通滤波器。
（a ）求系统2与系统1串联的冲激响应()t h 21
（b ）求一个与()t h 21并联后生成()()t t h p δ=的系统的冲激响应()t h 3 6. （5分）如图4所示信号，()t f 1的傅里叶变换()ωj F 1已知，求信号()t f 2的
傅里叶变换()ωj F 2。
图4
7. （10分）考察周期2=T 的连续时间周期信号()t x ，傅立叶级数系数为n F 如
下，求()t x 的傅立叶级数表达式。
100=F ，j F 23= j F 23−=− ，55=F 55=−F n others F n 0
=
8. （10分）用傅里叶变换性质和灵活方法，求图5所示信号()
t x 的傅里叶变换
（不用傅里叶变换定义直接求）。
图5
9. （10分）一个因果稳定的LTI 系统的频率响应函数为()ω
ωωωj j j H 564
2
+−+= (a) 确定该系统关于输入()t x 和输出()t y 的微分方程； (b) 确定该系统的冲激响应()t h ；
(c) 当输入()()()t u te t u e t x t t 44−−−=时，计算输出()t y 。
10. （5分）傅里叶变换为()ωj X 的信号()t x ，经冲激序列抽样得到
()()()nT t nT x t x n p −=
∑∞
−∞
=δ，其中 s T 410−=。
在 ()()0=∗ωωj X j X πω15000>
条件下，根据抽样定理，()t x 能够从()t x p 中正确的恢复吗？证明你的答案。
11. （5分）已知一线性时不变系统的幅频特性和相频特性如图6示，通过系统不产生失真的是下面哪一个信号，说明理由。
（A ）()t t t f 8cos cos +=（B ）()t t t f 4sin 2sin += （C ）()t t t f 4sin 2sin ⋅=（D ）()()t Sa t f π2=
图6
12. （15分）连续时间LTI 系统输入()t x 与输出()t y 关系由下列微分方程确定
()()()()()dt t dx dt t x d t y dt t dy dt t y d 2652222−=++
(a) 确定系统的传输函数()s H ；
(b)在()s H 的零极点图上画出所有可能的收敛域（ROCs ）;
(c)由给出的ROC 确定一个稳定系统（也就是()00
<=t t h ），并计算它的
冲激响应()t h
13. （15分）如图7所示RLC 电路实现的连续时间LTI 系统，电压源()t x 作为
系统的输入，电路中的电流()t y 作为系统的输出。
(
t x
图7
(a)画出这个系统的s 域模型图；； (b)求系统的系统函数()s H ；
(c)如果电阻R 可以调整，确定满足系统不震荡的R 的数值范围。
14. （15分）离散时间系统如图8所示，
图8
（a ）写出系统的差分方程式； （b ）求系统函数()z H ；
（c ）对于因果系统，判断系统的稳定性，并说明理由。
15. （15分）一个LTI 系统由下列一阶差分方程描述，
()()()n x n ay n y =−−1
(a) 确定系统的频率响应函数()
ωj e H 和单位样值响应()n h ； (b) 求幅频特性()
ωj e H 的表达式；
(c) 如果60.a =，画出幅频特性图()
ωω~e H j (d)根据幅频特性图，确定系统是低通、高通还是带通。
16. （5分）“一个信号()t f 不可能既是时间有限信号(即()τ>=t t f 当0)又是频
率有限信号(()[]σω>=当0t f F )”是信号分析中的基本常识之一。
请举两方面的例子论述。
17. （5分）确定下列系统是否为因果的、线性的，并证明你的结论。
()()()t x t x t y −+−=21
18. （5分）已知状态方程的矩阵
−=2010A ，求状态转移矩阵（矩阵指数）t
e A 。