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西工大线性系统考博真题

西工大线性系统考博真题
西工大线性系统考博真题

西北工业大学博士入学考试材料物理、材料综合复习题

2001博士秋季入学考试试题 1(16分)共价键的数目(为配位电子数)和方向(电子云密度最大方向)取决于什么?利用杂化轨道理论解释金刚石(sp 3)结构中的共价键,并计算碳的sp 3键的键角(109.28)。 2(12分)离子晶体在平衡时的结合能为:)11(80020n R NMe U E b -==πε,M 称为马德隆常数。试解释M 的意义。(西工大固体物理P41;M 是与晶体结构有关的常数) 3(12分)试比较经典的和量子的金属自由电子理论。(方俊鑫P285;黄昆P275) 4(12分)举例说明能带理论在解释固体材料有关性质(绝缘、半导、导体)、设计新材料中的应用。(西工大P111) 5(12分)解释金属及半导体的电阻率(高温时、低温时)随温度变化的规律。(西工大P192)

6(12分)分析固体表面的成分可采用那些分析技术和方法。(电子能谱:光电子能谱、俄歇电子、离子中和谱;离子谱:低能离子散射、高能离子散射、二次离子质谱、溅射中性粒子谱、致脱附离子角分布) 7(12分)晶体致的电缺陷有那些类型?分析其形成原因及对晶体性质的影响。(西工大P149、151) 8(12分)简述物质超到态的主要特征。(西工大P206、零电阻,充合抗磁) 答:1,低能电子衍射;2,表面敏感扩展X 吸收精细结构;3,场离子显微镜;4,电子显微镜;5,投射电子显微镜,扫描电子显微镜;6,扫描隧道显微镜;7,原子力显微镜;8,摩擦力显微镜 2001博士春季入学考试试题 1(16)N 对离子组成的NaCl 晶体的总互作用势能为 ??????-=R e R B N R U n 024)(πεα 其中α是马德隆常数,B 为晶格参量,n 为玻恩指数。 (1) 证明平衡原子间距为n e B R n 2 0104απε=- (2) 证明平衡时的结合能为)11(4)(0020n R Ne R U --=πεα

哈工大博士英语考试冲刺试题三

哈工大博士英语考试冲刺试题三 Passage 1 The realm of product liability is one that has always put legal scholars and practitioners at odds. Viewed by some as genuine efforts to protect the public from dangerous goods and others as an excuse for dirty lawyers to sue rich companies, the matter has yet to be resolved. Product liability, and its implications for disgruntled consumers wishing to sue the makers of what they buy, continues to be debated. Those who argue that current product liability laws are positive assert that without such laws, manufacturers would be free to do as they please without regard for the safety of the consumers who buy their products. As a result, they argue, shoddy merchandise would emerge, with every possible corner cut in order to lower costs, at the expense of quality. Not only would the shoddy merchandise be a rip-off, however, but the products could likely be harmful as well. Proponents of this point of view hail the new wave of warning labels and increased quality assurance that has resulted from recent product liability legislation, confident in their conviction that it has made the American marketplace a safer place to shop. Opponents of the current status-quo, however, cite the overwhelming amount of litigation that has taken place as a result of stricter product liability. A moderate approach id advised by this group, between the necessary safeguards that would prevent abuse of the system by the companies and the excessive consumer-protection laws that allow producers to be sued at the drop of a hat. These people argue that greed and the alluring possibility of easy money lead unscrupulous buyers to look for any excuse to bring minor grievances to court, hoping for a million-dollar outcome. As the situation stands now, the former camp is getting its way, reflecting society's priority of safety over economics. Recent lobbying by producers have begun to shift the tide, however, as abuse of product liability laws continues and grows, courts are beginning to note the trend and take appropriate measures, casting a keener eye on such cases so as to distinguish between frivolous cases and more serious claims. In regard to the future of product liability legislation and its relation to our ever increasingly litigious society, only time will tell. 1.It is stated that consumers who bring product liability problems to litigation ____ A.Are primarily motivated by the possibility of quick money through a lawsuit B.Suffer injures from faulty merchandise and deserve appropriate compensation C.Will find their options limited in the future as product liability laws will move toward a more moderate position D.Bring their issues to litigation based on both legitimate and profit-seeking groups 2.Manufacturers in the text tend to ____ A.Invariable produce dangerous products that require legislation to ensure safety B.Hold profit and cost-cutting in higher regard than consumer safety C.Be the victims of a legal institution that unfairly targets them D.Be bound by the current system, causing them to take caution in producing their products 3.Those who favor less strict product liability laws believe that ____ A.Such laws curb producers' ability to create shoddy merchandise to attain greater profit B.The laws need to be modified to better serve the needs both consumers and producers

考博英语(阅读理解)-试卷80.doc

考博英语(阅读理解)-试卷80 (总分:40.00,做题时间:90分钟) 一、Reading Comprehensio(总题数:4,分数:40.00) Too much alcohol dulls your senses, but a study in Japan shows that moderate drinkers have a higher IQ than teetotalers. Researchers at the National Institute for Longevity Sciences in Aichi Prefecture, 250 kilometers west of Tokyo, tested the IQs of 2000 people between the ages of 40 and 79. They found that, on average, men who drank moderately — defined as less than 540 milliliters of sake or wine a day — had an IQ that was 3. 3 points higher that men who did not drink at all. Women drinkers scored 2. 5 points higher than female teetotalers. The type of alcohol didn't influence the results. The volunteers tried a variety of tipples, which ranged from beer and whisky to wine and sake. The researchers are quick to point out that the results do not necessarily show that drinking will make you more intelligent. "It's very difficult to show a cause-effect relationship," says senior researcher Hiroshi Shimokata. "We screened subjects for factors such as income and education, but there may be other factors such as lifestyle and nutritional intake. " Shimokata says that people who drink sake, or Japanese rice wine, tend to eat more raw fish. This could be a factor in enhanced intelligence, as fish often contain essential fatty acids that have been linked to brain development. Similarly, wine drinkers eat a lot of cheese, which is not something Japanese people normally consume or buy. Shimokata says the high fat content of cheese is thought to be good for the brain. If alcoholic drinks are directly influencing IQ, Shimokata believes chemicals such as polyphenols could be the critical factor. They are known to have antioxidant properties and other beneficial effects on ageing bodies, such as dilating constricted coronary arteries. The study is part of a wider research project to find out why brain function deteriorates with age.(分数:10.00) (1).The Japanese study was carried out on______.(分数:2.00) A.the development of IQ B.the secret of longevity C.the brain food in a glass D.the amount of healthy drinking (2).The Japanese researchers found a higher IQ in______.(分数:2.00) A.female teetotalers than in male ones B.female drinkers than in male ones C.moderate drinkers D.teetotalers (3).When he says that it is very difficult to show cause-effect relationship, Shimokata means that______.(分数:2.00) A.the study failed to involve such variables as income and education B.he is doubtful of the findings of the investigation C.there are some other contributing factors D.the results were just misleading (4).From Shimokata's mention of fish and cheese we can infer that in enhancing intelligence______.(分数:2.00) A.sake or wine is a perfect match for fish and cheese B.they promote the drinking effect of sake or wine C.they are not as effective as sake and wine D.sake or wine is not alone (5).Based on the study, Shimokata would say that______.(分数:2.00) A.intelligence improves with age

哈工大考博英语真题及答案

General English Admission Test For Non-English Major Ph.D. program (Harbin Institute of Technology) Passage One Questions 1-7 are based on the following passage: According to a recent theory, Archean-age gold-quartz vein systems were formed over two billion years ago from magmatic fluids that originated from molten granitelike bodies deep beneath the surface of the Earth. This theory is contrary to the widely held view that the systems were deposited from metamorphic fluids, that is, from fluids that formed during the dehydration of wet sedimentary rocks. The recently developed theory has considerable practical importance. Most of the gold deposits discovered during the original gold rushes were exposed at the Earth’s surface and were found because the y had shed trails of alluvial gold that were easily traced by simple prospecting methods. Although these same methods still leas to an occasional discovery, most deposits not yet discovered have gone undetected because they are buried and have no surface expression. The challenge in exploration is therefore to unravel the subsurface geology of an area and pinpoint the position of buried minerals. Methods widely used today include analysis of aerial images that yield a broad geological overview, geophysical techniques that provide data on the magnetic, electrical, and mineralogical properties of the rocks being investigated, and sensitive chemical tests that are able to detect : the subtle chemical halos that often envelop mineralization. However, none of these high-technology methods are of any value if the sites to which they are applied have never mineralized, and to maximize the chances of discovery the explorer must therefore pay particular attention to selecting the ground formations most likely to be mineralized. Such ground selection relies to varying degrees on conceptual models, which take into account theoretical studies of relevant factors. These models are constructed primarily from empirical observations of known mineral deposits and from theories of ore-forming processes. The explorer uses the models to identify those geological features that are critical to the formation of the mineralization being modeled, and then tries to select areas for exploration that exhibit as many of the critical features as possible. 1. The author is primarily concerned with . A. advocating a return to an older methodology. B. explaining the importance of a recent theory. C. enumerating differences between two widely used methods D. describing events leading to a discovery 2. According to passage, the widely held view of Archean-age gold-quartz vein

西工大博士入学面试题【博士生面试英语自我介绍】

西工大博士入学面试题【博士生面试英语自 我介绍】 自我介绍的第一句话,很关键,不用说的很复杂。可以是一个简单句,但一定要铿锵有力。展示出自信和实力。千万不要来一句“sorry, my English is poor”,以下是X 为你整理的博士生面试英语自我介绍,希望大家喜欢。 博士生面试英语自我介绍篇1 Good morning, Dear Professors: It’s my honor to introduce myself. My name is XXX, I am fromXXCountyXXProvince, December XXXX I was born in a poor family, and my parents are farmers, I love and respect them very much. We were delight with my bexxing a fresh man in September 1997. Luckily, I was permitted to be a graduate student after 4 years colorful life on campus. I received my Bachelor degree20XX inXX Institute of Science and Technology, then a Master degree20XX inXX University of Science and Technology. For those 7 years my major was Die Design. Before I received my Master degree, I had done the subject of XXXXXXXXXXX. For the past 3 years, I have been inXXXXXXCollege, where I have been and still am

2017年武汉大学考博英语真题及答案

2017年武汉大学考博英语真题及答案 注意:所有的答题内容必须写在答案纸上,凡写在试题或草稿纸上的一律无效。 Part I Reading Comprehension (2’×20 = 40 points) Directions: In this part of the test, there will be 5 passages for you to read. Each passage is followed by 4 questions or unfinished statements, and each question or unfinished statement is followed by four choices marked A, B, C and D. You are to decide on the best choice by blackening the corresponding letter on the ANSWER SHEET. Passage One Mr Gordon is right that the second industrial revolution involved never-to-be-repeated changes. But that does not mean that driverless cars count for nothing. Messrs Erixon and Weigel are also right to worry about the West’s dismal recent record in producing new companies. But many old firms are not run by bureaucrats and have reinvented themselves many times over: General Electric must be on at least its ninth life. And the impact of giant new firms born in the past 20 years such as Uber, Google and Facebook should not be underestimated: they have all the Schumpeterian characteristics the authors admire. On the pessimists’ side the strongest argument relies not on closely watching corporate and investor behavior but rather on macro-level statistics on productivity. The figures from recent years are truly dismal. Karim Foda, of the Brookings Institution, calculates that labor productivity in the rich world is growing at its slowest rate since 1950. Total factor productivity (which tries to measure innovation) has grown at just 0.1% in advanced economies since 2004, well below its historical average. Optimists have two retorts. The first is that there must be something wrong

2008西工大博士考试英语真题答案及解析

Part 1 Reading comprehension Passage 1 Opinion poll surveys show that the public see scientists in a rather unflattering light. Commonly, the scientist is also seen as being male. It is true that most scientists are male, but the picture of science as a male activity may be a major reason why fewer girls than boys opt for science, except when it comes to biology, which is seen as “female.” The image most people have of science and scientists comes from their own experience of school science, and from the mass media. Science teachers themselves see it as a problem that so many school pupils find school science an unsatisfying experience, though over the last few years more and more pupils, including girls, have opted for science subjects. In spite of excellent documentaries, and some good popular science magazines, scientific stories in the media still usually alternate between miracle and scientific threat. The popular stereotype of science is like the magic of fairy tales: it has potential for enormous good or awful harm. Popular fiction is full of “good” scientists saving the world, and “mad” scientists trying to destroy it. From all the many scientific stories which might be given media treatment, those which are chosen are usually those which can be framed in terms of the usual news angles: novelty, threat, conflict or the bizarre. The routine and often tedious work of the scientist slips from view, to be replaced with a picture of scientists forever offending public moral sensibilities (as in embryo research), threatening public health (as in weapons research), or fighting it out with each other (in giving evidence at public enquiries such as those held on the issues connected with nuclear power). The mass media also tends to over-personalize scientific work, depicting it as the product of individual genius, while neglecting the social organization which makes scientific work possible. A further effect of this is that science comes to be seen as a thing in itself: a kind of unpredictable force; a tide of scientific progress. It is no such thing, of course. Science is what scientists do; what they do is what a particular kind of society facilitates, and what is done with their work depends very much on who has the power to turn their discoveries into technology, and what their interests are. 1. According to the passage, ordinary people have a poor opinion of science and scientists partly because ______. A) of the misleading of the media B) opinion polls are unflattering C) scientists are shown negatively in the media D) science is considered to be dangerous 2.. Fewer girls than boys study science because ______.

2017武大考博英语试题及答案

武汉大学 2017年攻读博士学位研究生外语综合水平考试试题 (满分值100分) 科目名称:英语科目代码:1101 注意:所有的答题内容必须写在答案纸上,凡写在试题或草稿纸上的一律无效。 Part I Reading Comprehension (2’×20 = 40 points) Directions:In this part of the test, there will be 5 passages for you to read. Each passage is followed by 4 questions or unfinished statements, and each question or unfinished statement is followed by four choices marked A, B, C and D. You are to decide on the best choice by blackening the corresponding letter on the ANSWER SHEET. Passage One Mr Gordon is right that the second industrial revolution involved never-to-be-repeated changes. But that does not mean that driverless cars count for nothing. Messrs Erixon and Weigel are also right to worry about the West’s dismal recent record in producing new companies. But many old firms are not run by bureaucrats and have reinvented themselves many times over: General Electric must be on at least its ninth life. And the impact of giant new firms born in the past 20 years such as Uber, Google and Facebook should not be underestimated: they have all the Schumpeterian characteristics the authors admire. On the pessimists’ side the strongest argument relies not on closely watching corporate and investor behavior but rather on macro-level statistics on productivity. The figures from recent years are truly dismal. Karim Foda, of the Brookings Institution, calculates that labor productivity in the rich world is growing at its slowest rate since 1950. Total factor productivity (which tries to measure innovation) has grown at just 0.1% in advanced economies since 2004, well below its historical average. Optimists have two retorts. The first is that there must be something wrong with the figures. One possibility is that they fail to count the huge consumer surplus given away free of charge on the internet. But this is unconvincing. The official figures may well be understating the impact of the internet revolution, just as they downplayed the impact of electricity and cars in the past, but they are not understating it enough to explain the recent decline in productivity growth. Another, second line of argument that the productivity revolution has only just begun is more persuasive. Over the past decade many IT companies may have focused on things that were more “fun than fundamental” in Paul Krugman’s phrase.But Silicon Valley’s best companies are certainly focusing on things that change the material world.

2015年北师大考博英语真题试卷

2015年北京师范大学考博英语真题试卷 (总分68, 做题时间90分钟) 1. Reading Comprehension The human ear contains the organ for hearing and the organ for balance. Both organs involve fluid-filled channels containing hair cells that produce electrochemical impulses when the hairs are stimulated by moving fluid. The ear can be divided into three regions: outer, middle, and inner. The outer ear collects sound waves and directs them to the eardrum separating the outer ear from the middle ear. The middle ear conducts sound vibrations through three small bones to the inner ear. The inner ear is a network of channels containing fluid that moves in response to sound or movement. To perform the function of hearing, the ear converts the energy of pressure waves moving through the air into nerve impulses that me brain perceives as sound. Vibrating objects, such as the vocal cords of a speaking person, create waves in me surrounding air. These waves cause the eardrum to vibrate with the same frequency. The three bones of the middle ear amplify and transmit the vibrations to the oval window, a membrane on the surface of the cochlea, the organ of hearing. Vibrations of me oval window produce pressure waves in the fluid inside me cochlea. Hair cells in the cochlea convert the energy of the vibrating fluid into impulses that travel along the auditory nerve to the brain. The organ for balance is also located in the inner ear. Sensations related to body position are generated much like sensations of sound. Hair cells in the inner ear respond to changes in head position with respect to gravity and movement. Gravity is always pulling down on the hairs, sending a constant series of impulses to the brain. When the position of the head changes—as when the head bends forward—the force on the hair cells changes its output of nerve impulses. The brain then interprets these changes to determine the head's new position. 1. What can be inferred about the organs for hearing and balance? A Both organs evolved in humans at the same time. B Both organs send nerve impulses to the brain. C Both organs contain the same amount of fluid. D Both organs are located in me ear's middle region. 2. Hearing involves all of the following EXCEPT______. A motion of the vocal cords so that they vibrate B stimulation of hair cells in fluid-filled channels C amplification of sound vibrations

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