郑景婷考研英语1420打印终极完整版

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Neural Network-based Correction and Interpolation of Encoder Signals for Precision Motion Control
Kok-Zuea Tang*, Kok-Kiong Tant , Tong-Heng Leet and Chek-Sing Teos *t@Department of Electrical and Computer Engineering
I. INTRODUCTION
In precision control, it is desirable to improve the resolution and accuracy of the overall control system. One way to achieve this aim is to improve the precision of the encoders used. However, the current state of the manufacturing technology of the encoders limits the achievable precision of encoders. Specifically, the scale grating on linear optical encoders can be manufactured to less than four micrometers in pitch, but clearly, further reduction in pitch will be greatly constrained by physical considerations. This implies an optical resolution of one micrometer can be currently achievable. Interpolation using soft techniques provides an interesting possibility to further improve on the encoder resolution, by processing the analog encoder signals online to derive the small intermediate positions. The error sources associated with positional information obtained this way can he classified under pitch and interpolation errors. Pitch errors arise mainly due t o scale manufacturing tolerances and mounting distortion. They can be compensated via the same prc+ cedures which are carried out for general geometrical error compensation. Interpolation errors, on the other hand, are associated with the accuracy of subdivision within a pitch. Ideal signals from encoders are a pair of sinusoids with a quadrature phase difference between them. Interpolation operates on the relative difference in the amplitudes and phases of these paired sinusoids. Therefore, interpolation errors will occur if the pairperiodic signals deviate from the ideal waveforms on which the interpolation computations are based. These

要不要报考辅导班？关于考研辅导班的研究介绍

要不要报考辅导班？关于考研辅导班的研究介绍关于考研辅导班下面说的这些都是建立在翻看论坛里面前辈们的帖子和各大考研结构2010免费动员班和宣传册的成果。

一、英语英语是考研里面最难的，但却是最没有必要报辅导班的，但是辅导班可以不上，课还是要听的，听新东方的有以下几个理由：1、考研英语每年变化不大，以前的解题思路技巧完全适用于最新的考试2、新东方的2009全套课程网上都有下载（基础班+强化班+冲刺班+各种单项）3、那些可下载的课程是专门为网络设计的，课件制作非常精细，效果非常好，而且都配发文本讲义，其他辅导班虽然也有录音下载但都是前辈们私录，效果参差不齐而且没有讲义教材不过这些只是次要的，新东方虽然强大，但他最多只能教你方法和思路，最关键的还是要靠自己下来练习，消化也就是说，不能把希望寄托于辅导班，辅导班只起辅助作用，不起决定作用二、数学我不考数学，但是因为前辈们的文章里面经常有介绍，所以顺带着看过，因为我不学，没有发言权，不过我对数学有一个感受就是数学辅导班的师资重合率很高也就是说，很多老师都在多家辅导班兼职，比如李永乐，我看了好几个辅导班的宣传册，都有他的名字，好奇搜索一下，貌似口碑也不错我的意思就是，数学似乎各个辅导班并没有明显的差距，但是因为不学，其他的我不敢多说三、政治政治是2010最纠结的一门课，因为换考试科目了，虽然万变不离其宗，但是很多东西是以前没有的，所以我感觉政治报班还是有必要的看了各个辅导班的宣传材料后，我感觉政治领域很混乱，老师很多不过我总结了一下，考研政治领域主要是两帮人，一个是人大的老师，特别是人大马克思主义学院，里面出来的老师太多了，另外一个就是西安交大，这个主要是以任汝芬为代表我仔细的看过论坛里面前辈们的经验，基本可以得出这样一个结论，任汝芬的书很好，但是讲课一般而人大的老师较为分散，也就是说不集中，可能这个老师擅长这门课那个老师又擅长那门课关于政治还要继续考察，不过好在政治的复习可以靠后一些，再考察一段时间再说四、总结还是那句话，这句话贯穿辅导班全程“不能把希望寄托于辅导班，辅导班只起辅助作用，不起决定作用，关键还是自己的努力”更不能相信辅导班能押题甚至漏题的鬼话另外辅导班现在都是商业化运作，宣传都是天花乱坠的，极具煽动性诱惑性，大家一定要淡定！淡定！全方位考察后再决定，浪费金钱事小，关键是浪费时间和精力另外还有一点，大家不能相信百度知道和百度贴吧，因为里面几乎全部是托，有正托也有反托，总之很混乱PS：发现两个无良考研机构，不过鉴于这篇帖子我是以一种客观的态度来写，这里就不明说了全国性考研辅导班概况评析1. 文都品牌实力：92--这是在考研辅导届子虚乌有的东西简评：1996年成立，办学11年，全国120个直属及加盟分校。

句句真研标静姐分数线考研英语语法

句句真研标静姐分数线考研英语语法Understanding the Syntax and Grammar of English Language for the Graduate English ExaminationIntroductionIn this document, we will delve into the intricacies of English syntax and grammar in preparation for the graduate English examination. We will explore key concepts such as sentence structure, parts of speech, verb tense, subject-verb agreement, and word order. Understanding these aspects of English language will not only help improve your writing and communication skills but also aid in achieving a high score on the examination. Let's begin our journey into the world of English language syntax and grammar.Sentence StructureEnglish sentences are typically structured in asubject-verb-object format. The subject is the entity performing the action, the verb is the action itself, and the object is the entity receiving the action. For example, in the sentence "Mary (subject) ate (verb) an apple (object)," Mary is the subject, ate is the verb, and apple is the object.Parts of SpeechThere are eight parts of speech in English: nouns, pronouns, verbs, adjectives, adverbs, prepositions, conjunctions, and interjections. Nouns are words that represent people, places, things, or ideas. Pronouns replace nouns in a sentence. Verbs express action or state of being. Adjectives describe nouns or pronouns. Adverbs modify verbs, adjectives, or other adverbs. Prepositions show the relationship between a noun or pronoun and other words in a sentence. Conjunctions connect words, phrases, or clauses. Interjections express emotion or sentiment.Verb TenseVerbs in English have different tenses to indicate when an action took place. The three primary verb tenses are past, present, and future. Each tense can be further subdivided into simple, continuous, perfect, and perfect continuous forms. For example, the simple past tense is used to describe actions that occurred in the past, such as "She walked to the store." The present continuous tense describes actions that are currently happening, as in "He is eating dinner."Subject-Verb AgreementSubject-verb agreement is essential to maintain grammatical correctness in a sentence. The verb in a sentence must agree with the subject in terms of number (singular or plural). Forexample, in the sentence "The cat (singular subject) is (singular verb) sleeping," the singular subject "cat" requires the singular verb "is." However, in the sentence "The cats (plural subject) are (plural verb) sleeping," the plural subject "cats" requires the plural verb "are."Word OrderIn English, word order plays a crucial role in conveying meaning. While the basic word order in English issubject-verb-object, there are variations based on the type of sentence (declarative, interrogative, imperative, or exclamatory) and the emphasis placed on certain words. For example, in a declarative sentence, the word order is subject-verb-object, as in "She (subject) plays (verb) the piano (object)." In an interrogative sentence, the word order is often inverted, as in "Does she (auxiliary verb) play (verb) the piano (object)?"ConclusionMastering the syntax and grammar of English language is essential for success in the graduate English examination. By understanding sentence structure, parts of speech, verb tense, subject-verb agreement, and word order, you can improve your writing skills and communication abilities. Remember to practice regularly and seek feedback to enhance your proficiency inEnglish language. Good luck with your preparations for the examination!。

(完整word版)研究生公共英语教材阅读B第3、4、10、11、14课文原文及翻译

Unite 3 Doctor's Dilemma: Treat or Let Die？Abigail Trafford1。

Medical advances in wonder drugs，daring surgical procedures，radiation therapies，and intensive—care units have brought new life to thousands of people. Yet to many of them, modern medicine has become a double-edged sword。

2。

Doctor’s power to treat with an array of space—age techniques has outstripped the body's capacity to heal. More medical problems can be treated，but for many patients，there is little hope of recovery. Even the fundamental distinction between life and death has been blurred。

3。

Many Americans are caught in medical limbo, as was the South Korean boxer Duk Koo Kim，who was kept alive by artificial means after he had been knocked unconscious in a fight and his brain ceased to function。

With the permission of his family，doctors in Las Vegas disconnected the life-support machines and death quickly followed。

最新2000-考研英语历年真题和答案(英语一)

ui2013年考研英语（一）真题.................................................................................................. 5Section I Use of English5 Section II Reading Comprehension. 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Choose the best word(s) for each numbered blank and mark A, B, C or D on ANSWER SHEET 1. (10 points)People are, on the whole, poor at considering background information when making individual decisions. At first glance this might seem like a strength that ___1___ the ability to make judgments which are unbiased by ___2___ factors. But Dr Simonton speculated that an inability to consider the big ___3___ was leading decision-makers to be biased by the daily samples of information they were working with. ___4___, he theorized that a judge ___5___ of appearing too soft ___6___crime might be more likely to send someone to prison ___7___he had already sentenced five or six other defendants only to forced community service on that day.To ___8___this idea, they turned their attention to the university-admissions process. In theory, the ___9___ of an applicant should not depend on the few others___10___ randomly for interview during the same day, but Dr Simonton suspected the truth was___11___.He studied the results of 9,323 MBA interviews ___12___ by 31 admissions officers. The interviewers had ___13___ applicants on a scale of one to five. This scale ___14___ numerous factors into consideration. The scores were ___15___ used in conjunction w ith an applicant’s score on the GMAT, a standardized exam which is ___16___out of 800 points, to make a decision on whether to accept him or her.Dr Simonton found if the score of the previous candidate in a daily series of interviewees was 0.75 points or more higher than that of the one ___17___ that, then the score for the next applicantwould___18___ by an average of 0.075 points. This might sound small, but to___19___the effects of such a decrease a candidate would need 30 more GMAT points than would otherwise have been ___20___.1. A grants B submits C transmits D delivers2. A minor B external C crucial D objective3. A issue B vision C picture D moment4. A Above all B On average C In principle D For example5. A fond B fearful C capable D thoughtless6. A in B for C to D on7. A if B until C though D unless8. A. test B. emphasize C. share D. promote9. A. decision B. quality C. status D. success10. A. found B. studied C. chosen D. identified11. A. otherwise B. defensible C. replaceable D. exceptional12. A. inspired B. expressed C. conducted D. secured13. A. assigned B. rated C. matched D. arranged14. A. put B. got C. took D. gave15. A. instead B. then C. ever D. rather16. A. selected B. passed C. marked D. introduced17. A below B after C above D before18. A jump B float C fluctuate D drop19. A achieve B undo C maintain D disregard20. A necessary B possible C promising D helpfulSection 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 SHEET 1. (40 points)Text 1In the 2006 film version of The Devil Wears Prada ,Miranda Priestly, played by Meryl Streep, scolds her unattractive assistant for imagining that high fashion doesn’t affect her, Priestly explains how the deep blue color of the assistant’s sweater descended over the years from fashion shows to departments stores and to the bargain bin in which the poor girl doubtless found her garment.This top-down conception of the fashion business couldn`t be more out of date or at odds with the feverish would described in Overdressed, Elizabeth Cline`s three-year indictment of “fast fashion”. In the last decade or so, advances in technology have allowed mass-market labels such as Zara, H&M, and Uniqlo to react to trends more quickly and anticipate demand more precisely. Quicker turnarounds mean less wasted inventory, more frequent release, and more profit. These labels encourage style-conscious consumers to see clothes as disposable-meant to last only a wash or two, although they don’t advertise that –and to renew their wardrobe every few weeks. By offering on-trend items at dirt-cheap prices, Cline argues, these brands have hijacked fashion cycles, shaking an industry long accustomed to a seasonal pace.The victims of this revolution, of course, are not limited to designers. For H&M to offer a $5.95 knit miniskirt in all its 2,300-pius stores around the world, it must rely on low-wage overseas labor, order in volumes that strain natural resources, and use massive amounts of harmful chemicals.Overdressed is the fashion world`s answer to consumer-activist bestsellers like Michael Pollan`s. The Omnivore`s Dilemma. “Mass-produced clothing ,like fast food, fills a hunger and need, yet is non-durable and wasteful,”Cline argues. Americans, she finds, buy roughly 20 billion garments a year – about 64 items per person – and no matter how much they give away, this excess leads to waste.Towards the end of Overdressed, Cline introduced her ideal, a Brooklyn woman named Sarah Kate Beaumont, who since 2008 has made all of her own clothes –and beautifully. But as Cline is the first to note, it took Beaumont decades to perfect her craft; he r example can’t be knocked off.Though several fast-fashion companies have made efforts to curb their impact on labor and the environment –including H&M, with its green Conscious Collection line –Cline believes lasting change can only be effected by the customer. She exhibits the idealism common to many advocates of sustainability, be it in food or in energy. Vanity is a constant; people will only start shopping more sustainably when they can’t afford not to.21. Priestly criticizes her assistant for her[A] poor bargaining skill.[B] insensitivity to fashion.[C] obsession with high fashion.[D] lack of imagination.22. According to Cline, mass-market labels urge consumers to[A] combat unnecessary waste.[B] shut out the feverish fashion world.[C] resist the influence of advertisements.[D] shop for their garments more frequently.23. The word “indictment”(Line 3, Para.2) is closest in meaning to[A] accusation.[B] enthusiasm.[C] indifference.[D] tolerance.24. Which of the following can be inferred from the last paragraph?[A] Vanity has more often been found in idealists.[B] The fast-fashion industry ignores sustainability.[C] People are more interested in unaffordable garments.[D] Pricing is vital to environment-friendly purchasing.25. What is the subject of the text?[A] Satire on an extravagant lifestyle.[B] Challenge to a high-fashion myth.[C] Criticism of the fast-fashion industry.[D] Exposure of a mass-market secret.Text 2An old saying has it that half of all advertising budgets are wasted-the trouble is, no one knows which half. In the internet age, at least in theory, this fraction can be much reduced. By watching what people search for, click on and say online, compani es can aim “behavioral” ads at those most likely to buy.In the past couple of weeks a quarrel has illustrated the value to advertisers of such fine-grained information: Should advertisers assume that people are happy to be tracked and sent behavioral ads? Or should they have explicit permission?In December 2010 America's Federal Trade Commission (FTC) proposed adding a "do not track "(DNT) option to internet browsers ,so that users could tell advertisers that they did not want to be followed .Microsoft's Internet Explorer and Apple's Safari both offer DNT ;Google's Chrome is due to do so this year. In February the FTC and Digital Advertising Alliance (DAA) agreed that the industry would get cracking on responding to DNT requests.On May 31st Microsoft Set off the row: It said that Internet Explorer 10, the version due to appear windows 8, would have DNT as a default.It is not yet clear how advertisers will respond. Getting a DNT signal does not oblige anyone to stop tracking, although some companies have promised to do so. Unable to tell whether someone really objects to behavioral ads or whether they are sticking w ith Microsoft’s default, some may ignore a DNT signal and press on anyway.Also unclear is why Microsoft has gone it alone. After all, it has an ad business too, which it says will comply with DNT requests, though it is still working out how. If it is trying to upset Google, which relies almost wholly on default will become the norm. DNT does not seem an obviously huge selling point for windows 8-though the firm has compared some of its other products favorably with Google's on that count before. Brendon Lynch, MMicrosoft's chief privacy officer, blogged: "we believe consumers should have more control." Could it really be that simple?26. It is suggested in paragraph 1 that “behavioral”ads help advertisers to:[A] ease competition among themselves[B] lower their operational costs[C] avoid complaints from consumers[D] provide better online services27. “The industry”(Line 6,Para.3) refers to:[A] online advertisers[B] e-commerce conductors[C] digital information analysis[D] internet browser developers28. Bob Liodice holds that setting DNT as a default[A] many cut the number of junk ads[B] fails to affect the ad industry[C] will not benefit consumers[D] goes against human nature29. which of the following is true according to Paragraph.6?[A] DNT may not serve its intended purpose[B] Advertisers are willing to implement DNT[C] DNT is losing its popularity among consumers[D] Advertisers are obliged to offer behavioral ads30. The author's attitude towards what Brendon Lynch said in his blog is one of:[A] indulgence[B] understanding[C] appreciation[D] skepticismText 3Up until a few decades ago, our visions of the future were largely - though by no means uniformly - glowingly positive. Science and technology would cure all the ills of humanity, leading tolives of fulfillment and opportunity for all.Now utopia has grown unfashionable, as we have gained a deeper appreciation of the range of threats facing us, from asteroid strike to epidemic flu and to climate change. You might even be tempted to assume that humanity has little future to look forward to.But such gloominess is misplaced. The fossil record shows that many species have endured for millions of years - so why shouldn't we? Take a broader look at our species' place in the universe, and it becomes clear that we have an excellent chance of surviving for tens, if not hundreds, of thousands of years . Look up Homo sapiens in the "Red List" of threatened species of the International Union for the Conversation of Nature (IUCN) ,and you will read: "Listed as Least Concern as the species is very widely distributed, adaptable, currently increasing, and there are no major threats resulting in an overall population decline."So what does our deep future hold? A growing number of researchers and organizations are now thinking seriously about that question. For example, the Long Now Foundation has its flagship project a medical clock that is designed to still be marking time thousands of years hence.Perhaps willfully, it may be easier to think about such lengthy timescales than about the more immediate future. The potential evolution of today's technology, and its social consequences, is dazzlingly complicated, and it's perhaps best left to science fiction writers and futurologists to explore the many possibilities we can envisage. That's one reason why we have launched Arc, a new publication dedicated to the near future.But take a longer view and there is a surprising amount that we can say with considerable assurance. As so often, the past holds the key to the future: we have now identified enough of the long-term patterns shaping the history of the planet, and our species, to make evidence-based forecasts about the situations in which our descendants will find themselves.This long perspective makes the pessimistic view of our prospects seem more likely to be a passing fad. To be sure, the future is not all rosy. But we are now knowledgeable enough to reduce many of the risks that threatened the existence of earlier humans, and to improve the lot of those to come.31. Our vision of the future used to be inspired by[A] our desire for lives of fulfillment[B] our faith in science and technology[C] our awareness of potential risks[D] our belief in equal opportunity32. The IUCN`s “Red List”suggest that human being are[A] a sustained species[B] a threaten to the environment[C] the world`s dominant power[D] a misplaced race33. Which of the following is true according to Paragraph 5?[A] Arc helps limit the scope of futurological studies.[B] Technology offers solutions to social problem.[C] The interest in science fiction is on the rise.[D] Our Immediate future is hard to conceive.34. To ensure the future of mankind, it is crucial to[A] explore our planet`s abundant resources[B] adopt an optimistic view of the world[C] draw on our experience from the past[D] curb our ambition to reshape history35. Which of the following would be the best title for the text?[A] Uncertainty about Our Future[B] Evolution of the Human Species[C] The Ever-bright Prospects of Mankind[D] Science, Technology and HumanityText 4On a five to three vote, the Supreme Court knocked out much of Arizona's immigration law Monday-a modest policy victory for the Obama Administration. But on the more important matter of the Constitution, the decision was an 8-0 defeat for the federal government and the states.In Arizona, United States, the majority overturned three of the four contested provisions of Arizona's controversial plan to have state and local police enforce federal immigrations law. The Constitutional principles that Washington alone has the power to "establish a uniform Rule of naturalization" and that federal laws precede state laws are noncontroversial. Arizona had attempted to fashion state police that ran to the existing federal ones.Justice Anthony Kennedy, joined by Chief Justice John Roberts and the Court's liberals, ruled that the state flew too close to the federal sun. On the overturned provisions the majority held the congress had deliberately "occupied the field" and Arizona had thus intruded on the federal's privileged powersHowever, the Justices said that Arizona police would be allowed to verify the legal status of people who come in contact with law enforcement. That`s because Congress has always envisioned joint federal-state immigration enforcement and explicitly encourages state officers to share information and cooperate with federal colleagues.Two of the three objecting Justice-Samuel Alito and Clarence Thomas-agreed with this Constitutional logic but disagreed about which Arizona rules conflicted with the federal statute. The only major objection came from Justice Antonin Scalia, who offered an even more robust defense of state privileges going back to the alien and Sedition Acts.The 8-0 objection to President Obama turns on what Justice Samuel Alito describes in his objection as “a shocking assertion of federal executive power”. The White House argued the Arizona`s laws conflicted with its enforcement priorities, even if state laws complied with federal statutes to the letter. In effect, the White House claimed that it could invalidate any otherwise legitimate state law that it disagrees with.Some powers do belong exclusively to the federal government, and control of citizenship and the borders is among them. But if Congress wanted to prevent states from using their own resources to check immigration status. It never did so. The administration was in essence asserting that because it didn't want to carry out Congress's immigration wishes, no state should be allowed to do so either. Every Justice rightly rejected this remarkable claim.36. Three provisions of Arizona`s plan were overturned because they[A] deprived the federal police of Constitutional powers.[B] disturbed the power balance between different states.[C] overstepped the authority of federal immigration law.[D] contradicted both the federal and state policies.37. On which of the following did the Justices agree, according to Paragraph4?[A] Federal officers` duty to withhold immigrants` information.[B] States` independence from federal immigration law.[C] States` legitimate role in immigration enforcement.[D] Congress`s intervention in immigration enforcement.38. It can be inferred from Paragraph 5 that the Alien and Sedition Acts[A] violated the Constitution.[B] undermined the states` interests.[C] supported the federal statute.[D] stood in favor of the states.39. The White House claims that its power of enforcement[A] Outweighs that held by the states.[B] is dependent on the states` support.[C] is established by federal statutes.[D] rarely goes against state laws.40. What can be learned from the last paragraph?[A] Immigration issues are usually decided by Congress.[B] Justices intended to check the power of the Administration.[C] Justices wanted to strengthen its coordination with Congress.[D] The Administration is dominant over immigration issues.Part BDirections:In the following text, some sentences have been removed. For Questions 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 blanks. Mark your answers on ANSWER SHEET1.（10 points）The social sciences are flourishing. As of 2005, there were almost half a million professional socialscientists from all fields in the world, working both inside and outside academia. According to the World Social Science Report 2010, the number of social-science students worldwide has swollen by about 11% every year since 2000.Yet this enormous resource in not contributing enough to today`s global challenges including climate change, security, sustainable development and health.(41)______Humanity has the necessary agro-technological tools to eradicate hunger , from genetically engineered crops to artificial fertilizers . Here, too, the problems are social: the organization and distribution of food, wealth and prosperity.(42)____This is a shame—the community should be grasping the opportunity to raise its influence in the real world. To paraphrase the great social scientist Joseph Schumpeter: there is no radical innovation without creative destruction.Today, the social sciences are largely focused on disciplinary problems and internal scholarly debates, rather than on topics with external impact.Analyses reveal that the number of papers including the keywords “environmental changed”or “climate change”have increased rapidly since 2004,(43)____When social scientists do tackle practical issues, their scope is often local: Belgium is interested mainly in the effects of poverty on Belgium for example .And whether the community’s work contributes much to an overall accumulation of knowledge is doubtful.The problem is not necessarily the amount of available funding (44)____this is an adequate amount so long as it is aimed in the right direction. Social scientists who complain about a lack of funding should not expect more in today`s economic climate.The trick is to direct these funds better. The European Union Framework funding programs have long had a category specifically targeted at social scientists. This year, it was proposed that system bechanged: Horizon 2020, a new program to be enacted in 2014, would not have such a category. This has resulted in protests from social scientists. But the intention is not to neglect social science; rather, the complete opposite. (45)____That should create more collaborative endeavors and help to develop projects aimed directly at solving global problems.[A] It could be that we are evolving two communities of social scientists: one that is discipline-oriented and publishing in highly specialized journals, and one that is problem-oriented and publishing elsewhere, such as policy briefs.[B] However, the numbers are still small: in 2010, about 1,600 of the100,000 social-sciences papers published globally included one of these keywords.[C] The idea is to force social to integrate their work with other categories, including health and demographic change food security, marine research and the bio-economy, clear, efficient energy; and inclusive, innovative and secure societies.[D] The solution is to change the mindset of the academic community, and what it considers to be its main goal. Global challenges and social innovation ought to receive much more attention from scientists, especially the young ones.[E] These issues all have root causes in human behavior. All require behavioral change and social innovations, as well as technological development. Stemming climate change, for example, is as much about changing consumption patterns and promoting tax acceptance as it is about developing clean energy.[F] Despite these factors, many social scientists seem reluctant to tackle such problems. And in Europe, some are up in arms over a proposal to drop a specific funding category for social-science research and to integrate it within cross-cutting topics of sustainable development.[G] During the late 1990s , national spending on social sciences and the humanities as apercentage of all research and development funds-including government, higher education, non-profit and corporate -varied from around 4% to 25%; in most European nations , it is about 15%. 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 speculated that gardens arise from a basic need in the individuals who made them: the need for creative expression. There is no doubt that gardens evidence an impossible urge to create, express, fashion, and beautify and that self-expression is a basic human urge; (46) Yet when one looks at the photographs of the garden created by the homeless, it strikes one that, for all their diversity of styles, these gardens speak of various other fundamental urges, beyond that of decoration and creative expression.One of these urges had to do with creating a state of peace in the midst of turbulence, a “still point of the turning world,”to borrow a phrase from T. S. Eliot. (47)A sacred place of peace, however crude it may be, is a distinctly human need, as opposed to shelter, which is a distinctly animal need. This distinction is so much so that where the latter is lacking, as it is for these unlikely gardens, the former becomes all the more urgent. Composure is a state of mind made possible by the structuring of one’s relation to one’s environment. (48) The gardens of the homeless which are in effect homeless gardens introduce from into an urban environment where it either didn’t exist or was not discernible as such. In so doing they give composure to a segment of the inarticulate environment in which they take their stand.Another urge or need that these gardens appear to respond to, or to arise from is so intrinsic that we are barely ever conscious of its abiding claims on us. When we are deprived of green, of plants, of trees, (49) most of us give into a demoralization of spirit which we usually blame on some。

AADE-14-FTCE-05

Copyright 2014, AADEThis paper was prepared for presentation at the 2014AADE Fluids Technical Conference and Exhibition held at the Hilton Houston North Hotel, Houston, Texas, April 15-16, 2014. This conference was sponsored by the American Association of Drilling Engineers. The information presented in this paper does not reflect any position, claim or endorsement made or implied by the American Association of Drilling Engineers, their officers or members. Questions concerning the content of this paper should be directed to the individual(s) listed as author(s) of this work.AbstractDuring cementing operation, it is critical to determine the flowing of cement slurry between the casing and formation, depth of the circulation losses and fluid loss, setting of cement in place and performance of the cement after hardening. Recent case studies on cementing failures have clearly identified some of these issues that resulted in various types of delays in the cementing operations. At present there is no technology available to monitor cementing operations in real time from the time of placement through the borehole service life. Also, there is no reliable method to determine the length of the competent cement supporting the casing.In this study oil well cement with better sensing properties, henceforth called smart cement, was used to verify that its behavior can be monitored at various stages of construction and during its service life. A series of experiments evaluated the smart well cement behavior with and without up to 0.3% sodium metasilicate (SMS) to determine the sensitivity of the electrical resistivity of cement from curing to hardened state was investigated. The test results showed that SMS reduced the electrical resistivity of the water and cement slurries based on the amount. The SMS up to 0.3% also affected the rheological properties, setting characteristics, and the piezoresistive properties of the smart cement. In a 24-hour period the maximum change in the electrical resistivity (RI24) for the cement without SMS (0.4 water-to-cement ratio) was 175%. The RI24for the cement with SMS varied with the amount of SMS. Addition of 0.2% SMS had a minimal effect on the compressive strength. The smart cement was piezoresistive with the addition of SMS but the sensitivity was decreased.IntroductionAs deepwater exploration and production of oil and gas expands around the world, there are unique challenges in well construction beginning at the seafloor. Recent case studies on cementing failures have clearly identified several issues that resulted in various types of delays in the cementing operations. Also preventing the loss of fluids to the formations and proper well cementing have become critical issues in well construction to ensure wellbore integrity because of varying down hole conditions (Labibzadeh et al., 2010; Eoff et al., 2009; Ravi et al,. 2007; Gill et al., 2005; Fuller et al., 2002). Moreover, the environmental friendliness of the cements is a critical issue that is becoming increasingly important (Dom et al., 2007; Thaemlitz et al., 1999; Durand et al., 1995). Lack of cement returns may compromise the casing support, and excess cement returns can cause problems with flow and control lines (Ravi et al. 2007; Gill et al. 2005; Fuller et al. 2002). Hence there is a need for monitoring the cementing operation in real time. At present there is no technology available to monitor the cementing operation real time from the time of placement through the entire service life of the borehole. Also, there is no reliable method to determine the length of the competent cement supporting the casing.In characterize the behavior of cementitious materials several methods such as X-ray diffraction, calorimetric analysis, scanning electron microscopy, and ultrasonic methods have been in used. Electrical resistivity measurement has been applied by many researches on concrete and other cementing applications (Taylor and Arulanandan, 1974; McCarter et al., 1998and 2006; Vipulanandan et al. 2006), but there are no reports in the literature of electrical resistivity measurements for characterizing oilwell cement. Electrical response characteristics measurement has appropriate sensitivity in monitoring the characteristics of cementitious materials (McCarter et al., 1998). The advantages in using this technique include its accuracy, ease of testing and procedures, and nondestructive characteristics (Vipulanandan et al., 2004-2013). Additionally, this method can be used for monitoring the long term behavior of cement in practice.Electrical resistivity of cement is affected by a number of factors, such as pore structure (continuity and tortuosity), pore solution composition, cementitious content, water-cement (w/c) ratio, moisture content, and temperature (Polder et al., 2001). Moreover, electrical resistivity of cement is dramatically affected by admixtures, due to the resistivity contrast between cement and the admixture substances. Vipulanandan et al. (2004, 2006-2013) have studied the change in electrical resistivity with applied stress, referred to as piezoresistive behavior of modified cementitious and polymer composites. The studies showed that the changes inAADE-14-FTCE-05Characterizing Smart Cement with Sodium Metasilicate for Real Time Monitoring of Ultra-Deepwater Oil Well Cementing ApplicationsCumaraswamy Vipulanandan and Kausar Ali, CIGMAT-University of Houston, Guido Narvaez, Baker Hughes; Donald A.Richardson and James M. Pappas, Research Partnership to Secure Energy for America2 C. Vipulanandan, K. Ali, G. Narvvaez, D. Richardson and J. Pappas AADE-14-FTCE-05resistivity with the applied stress were 30 to 50 times higher than the strain in the materials. Hence, the change in resistivity has the potential to be used to determine the integrity of the materials.Sodium metasilicate (SMS)From the initial use in the late 1800’s sodium silicate based compounds have been used in a number of applications including cementing, grouting, emulsifying, and in cleaning agents. Of the various forms of sodium silicate based compounds, sodium meta silicates (anhydrous) have been used in oil and gas industry related applications. Because of its emulsification and interfacial tension reduction characteristics, SMS has been used in alkaline flooding, a chemical recovery method to recover oil from various types of geological formations and sand (Larrondo et al. 1985).Based on the chemical composition of sodium metasilicate (Na2SiO3), it can react with the cement hydration products, forming various types of calcium silicate hydration gels. Fasesan et al. (2005) investigated the use of 0.5% of sodium metasilicate (by weight of cement) in 50:50 class H cement slurry to replace the 2% bentonite. The study showed that the sodium metasilicate was effective in controlling free water and fluid loss. In many parts of the world, severe lost circulation and weak formations with low fracture characteristics are common. These situations require the use of low-density cement systems that reduce the hydrostatic pressure of the fluid column during the cement placement process. Hence lightweight additives (also known as extenders) are used to reduce the weight of the slurry. Malyshev et al. (2013) used SMS as the extender for a lightweight cement system of density 1500 kg/m3 (12.6 ppg). Hence SMS has multifunctional ability to modify the oil well cement.ObjectivesThe overall objective of the study was to determine the effect of sodium metasilicate on the behavior of smart oil well cement. The specific objectives are as follows:(i) Effect of SMS on the rheological, curing, and electricalproperties of smart oil well cement.(ii) Effect of SMS on the piezoresistive behavior of hardened smart oil well cement.Materials and MethodsMaterialsSmart CementCommercially available oil well cement (Class H cement) was modified with additives to make it a piezoresistive material.Sodium MetasilicateSodium metasilicate, also known as disodium metasilicate, used in this study is a white, odorless, granular anhydrous powder. Based on the data sheet provided by the chemical manufacturer, it has a molecular weight of 122 g/mol, pH of12.5 at 10 g/l at 20 °C (68 °F), melting point of1,090 °C (1,994 °F), density of 2.61 g/cm3 at 20 °C (68 °F), and water solubility of 350 g/L at 20 °C (68 °F).MethodsSodium metasilicate (SMS) solutionThe samples were prepared by mixing selected amount of SMS powder (by weight of water) in water at room temperature. The mixture was blended using a table top blender and the pH was monitored at the end of mixing. Up to 5% SMS solution was prepared to characterize the electrical resistivity properties. Water with and without SMS was used to prepare the cement specimens.Cement MixtureThe samples were prepared according to the API standards. Smart cement with a cement-to-water ratio of 0.4 was used in this study. Two series of cement slurries were prepared with and without selected amount of SMS (0.2%). Cement Specimen PreparationAfter mixing, specimens were prepared using cylindrical molds with a diameter of 2 inches and a height of 4 inches. Two conductive wires were placed in all of the molds which were 5 cm apart. All specimens were capped to minimize moisture loss and were cured up to the day of testing for the piezoresisitivity under compressive loading. Rheological TestsRheological properties determine the ability of cement to be pumped. The rheology tests were performed by utilizing a rotational viscometer at room pressure and temperature at rpms ranging from 3 to 600, and related shear stresses were recorded. The viscometers were calibrated using several standard solutions.Electrical ResistivitySMS SolutionA commercially available conductivity probe was used to measure the conductivity (inverse of resistivity) of the fluids. The resistivity measuring range was from 0.1 Ω.mto10,000Ω.m.Cemen tBased on the results of past studies, electrical resistivity was selected as a monitoring parameter to quantify the performance of modified cement during the curing and hardening process (Vipulanandan et al.2004-2013). Electrical resistivity of the slurries was measured using an API standard resistivity meter. Further, electrical resistance was measured using an inductance –capacitance - resistance (LCR) meter during the curing time. To minimize the contact resistances, the resistance was measured at 300 kHz using the two-wireAADE-14-FTCE-05Characterizing Smart Cement with Sodium Metasilicate for Real Time Monitoring of Oil Well Cement 3method (Vipulanandan et al., 2013). The principle of measuring the resistance is shown in Figure1. Each specimen was calibrated to obtain the electrical resistivity (ρ) from the measured electrical resistance (R) based on the Eqn. (1).ρ = RA/L = R/(L/A) = R/K (1)where L is the distance between the wires, A is the cross-sectional area through which the current is flowing, and L/A is called the geometry factor K. Where parameter K=L/A, the ratio of the cross-sectional area and the length of the material is defined for a particular set-up. If we know the resistivity and the resistance of the material then from the relationship in Eqn. (1) we can determine the parameter K. The resistivity of each cement slurry was determined using the API resistivity meter. Figure 2 shows K values determine for four different cement slurries such as cement slurry with and without Sodium Meta-silicate (SMS). After about 5 hours (300 min), the K value stabilized and it was used to determine the resistivity of the hardened cement specimens. Compressive Strength Tests.Compressive strength of cement determines the ability of cement to stabilize casing in the wellbore. The cylindrical specimen was capped and tested at a predetermined controlled displacement rate. Compression tests were performed on cement samples after 2 and 7 days of curing using a hydraulic compression machine.Piezoresistivity Tests.Piezoresisitivity describes the change in electrical resistivity of a material under pressure. Since oil well cement serves as a pressure-bearing part of wells in real applications, the piezoresistivity of smart cement with and without SMS was investigated under compressive loading. During each compression test, electrical resistance was measured in the stress axis. To eliminate the polarization effect, alternating current (AC) resistance measurements were made using a LCR meter at a frequency of 300 KHz. Furthermore, changes in resistivity were related to the applied stress.Results and DiscussionsResultsThe average unit weight of the cement slurry was 121. 5 pcf.SMS SolutionpHAddition of SMS to the water increased the pH as shown in Figure 3. With the addition of 0.1% SMS, the water pH increased from 7.7 to 11.8, a 50% change in the pH. With the addition of 0.3% SMS the pH was 12.4.ResistivityThe resistivity of sodium metasilicate solution was determined with the conductivity probe. SMS solution was very sensitive to electrical resistivity. The resistivity of water decreased from 21Ω.m to 4.15 Ω.m with an addition of only 0.1% SMS (Figure 4), 80% reduction in resistivity. The addition of more SMS further reduced the resistivity of the solution. The following relationship is proposed based on the experimental results:ρ = ρo– S/(E +DS) (2)where:ρ = resistivity of the sodium metasilicate solutionρo = resistivity of tap water without sodium metasilicate(21 Ω.m)S = Concentration of sodium metasilicate (% byweight)Parameters E and D are model parameters: parameter E represent the initial rate of change and parameter D determines the ultimate resistivity. Experimental results matched very well with the proposed model with a coefficient of determination (R2) of 0.98, and parameters E and D were found as 0.0016/Ω.m and 0.047/Ω.m, respectively. Rheological propertiesGel StrengthFor the smart cement, after 10 seconds gel strength was 12 lb/100 ft2, and after 10 minutes gel strength was 14 lb/100 ft2.With the addition of 0.2% SMS to the cement the 10-second gel strength was 15 lb/100 ft2and the 10-minute gel strength was 17 lb/100 ft2. Hence, addition of 0.2 SMS increased the 10-second gel strength by 25% and the 10-minute gel strength by 21%.Effect of SMSIt was evident from the rheological tests on cement slurries with and without 0.2% SMS that the addition of SMS negatively affects the shear-thinning behavior of cement. Addition of SMS increased the viscous behavior of the cement. For instance, the viscosity of cement without SMS at a shear strain rate of 100 (1/sec) was 146 cP. At the same shear strain rate the 0.2 percent SMS sample had viscosity of 225 cP, a 54% increase in viscosity.ModelingDue to the shear-thinning behavior of the cement slurries the Bingham plastic model was not an accurate model to estimate the shear strain rate – shear stress relationship. To predict the shear strain rate - shear stress relationship, the Herschel-Bulkley model (Eqn.3) and hyperbolic model (Eqn.4) were used to predict the experimental data.The Herschel–Bulkley (H-B) model follows:τ = τo+ k γn (3)where:τ= shear stressγ= shear rateτo= yield stressk and n are model parameters.From the smart cement, the k and n were found to be4 C. Vipulanandan, K. Ali, G. Narvvaez, D. Richardson and J. Pappas AADE-14-FTCE-051.09 and 0.78, respectively (Figure 5). The coefficient of determination (R2) was 0.97. The yield stress was found as 1.87 lb/100 ft2.For the cement slurry with 0.2% sodium meta-silicate the k and n (for Herschel–Bulkley model)were found to be 0.61 and 0.88, respectively (Figure 6). The coefficient of correlation was 0.99. The yield stress was 13.8 lb/100 ft2, a notable increase in the yield stress with the addition of 0.2% SMS.The hyperbolic model is as follows:τ= τo + γ/(A+Bγ) (4)where.τ= shear stressτo= yield stressA andB are model parameters.Here for the smart cement parameters A and B were found as 2.83(Pa.sec)-1and 0.001Pa-1,respectively, and the coefficient of determination (R2) was 0.97. The yield stress was 5.01 lb/100 ft2. The apparent viscosity at 600 RPM was 106 cP.For the smart cement with 0.2 SMS, the hyperbolic model parameters A and B were found as3.21(Pa.sec)-1and 0.0004Pa-1,respectively, and the coefficient of determination (R2) was found to be 0.99. The yield stress was17.4lb/100 ft2.With the addition of 0.2% SMS the apparent viscosity at 600 RPM was 136 cP, a 28% increase.Fluid LossFor the smart cement the total fluid loss was 137 cc. Smart cement (w/c ratio of 0.4) with the addition of 0.2% SMS had a fluid loss of 145 cc (Figure 7), hence a 6% increase in the fluid loss.Electrical ResistivityInitial ResistivityThe electrical resistivity of the cement slurry with and without SMS was determined. The initial resistivity of the smart cement slurry was 0.97 Ω.m, and it decreased with the addition of sodium metasilicate, as shown in Figure8. With the addition of 0.1% SMS the resistivity decreased to 0.92 Ω.m, a 5% reduction. With the addition of 0.2% and 0.3%SMS the resistivity were 0.9 Ω.m and 0.88 Ω.m. Hence the resistivity was sensitive to the concentration of SMS in the cement. Resistivity during Curing ProcessElectrical resistivity could be used as a fingerprint of the curing process. Figure 9 illustrates the change in electrical resistivity (ρ) during curing time for smart cement with and without SMS. It was observed that the curves of the different samples, with and without SMS, follow a similar trend with time. The electrical resistivity dropped to a minimum value, and then gradually increased with time. After initially mixing cement with water, resistivity decreased to a minimum value (ρmin), and the corresponding time to reach the minimum resistivity was t min. The decrease in resistivity immediately after mixing was due to dissolution of soluble ions from the cement particles after cement was mixed with water, and the dissolving process of the ions caused the resistivity decrease during early periods. The term t min can be used as an index of speed of chemical reactions and cement set times. With the formation of resistive solid hydration products that block the conduction path, resistivity increased sharply with curing time. The following increase in electrical resistivity was caused by the formation of a large amount of hydration products in the cement matrix. Finally, a relatively stable increasing trend was reached by the ion diffusion control of hydration process. Resistivity increased steadily up to 24 hours and reached a value of ρ24. Change in electrical resistivity with respect to minimum resistivity quantifies the formation of solid hydration products, which leads to the strength development in the curing cement. Therefore, by tracking the change in resistivity of oil well cement, a clear understanding of the hydration process and strength development can be obtained. Hence the Resistivity Index at 24 hours (RI24) is defined as the maximum change in resistivity in 24 hours to reflect the changes in resistivity.Variations in electrical resistivity with time for samples with different amounts of SMS are summarized in Table 1. Increasing SMS content decreased the minimum resistivity of cement (ρmin). This is another indicator of the increased chemical reaction between the cement and SMS. With 0.2 percent SMS the minimum resistivity of cement decreased from 0.81 Ω.m to 0.75 Ω.m,a 7.5% percent decrease. Also, addition of SMS increased both the t min, and the rate of change in resistivity. RI(24)for the smart cement was 175 percent (Table 1). With the addition of SMS, RI(24) varied from 178 to 196 (%). In general, higher change in electrical resistivity (ρ24–ρmin) indicates that increased hydration products are developed in the hydrating cement system.Compressive StrengthEffect of SMSThe compressive strength of smart cement without any SMS was 1.0 ksi and 2.5 ksi after 2 days and 7 days of curing, respectively. As shown in Figs. 10 and 11, the addition of 0.2% SMS did not affect the compressive strength of cement. PiezoresistivityThe piezoresistive behavior (compressive stress versus change in resistivity) of cement with and without SMS is shown in Figs. 10 and 11 after 2 days and 7 days curing, respectively. Electrical resistivity was sensitive to compressive stress. Figures 10 and 11 show that electrical resistivity increased during compressive loading. Addition of SMS reduced the piezoresistive response of smart cement. After two days of curing the smart cement failed at a resistivity change of 550 percent, while the 0.2 percent SMS added cement failed at a resistivity change of 150 percent. After seven days of curing the smart cement failed at a resistivity change of 800 percent, while the 0.2 percent SMS added cement failed at a resistivity change of 200 percent. The failure strain is 0.25 percent, and hence the change in the resistivity of cement with 0.2 percent of SMS was 800 times higher than the strain.AADE-14-FTCE-05Characterizing Smart Cement with Sodium Metasilicate for Real Time Monitoring of Oil Well Cement 5ConclusionsBased on this experimental and analytical study on smart cement with the addition of sodium metasilicate (SMS), the following conclusions are advanced:1)Addition of 0.1% SMS increased the pH and reducedthe resistivity of water by 50% and 80%,respectively. The change in resistivity of water withthe addition of SMS has been modeled.2)Addition of 0.2% SMS increased both the 10-secondand 10-minute gel strength by over 20%.3)Addition of 0.2% SMS increased the yield strength,viscosity, and fluid loss. Shear stress and shear strainrate relationships have been modeled.4)Electrical resistivity developments with hydrationtime of the cement with different amounts of SMSfollow a similar pattern: they first drop to a minimumpoint and then gradually increase with time. Theminimum resistivity decreased, and the time toachieve minimum resistivity (rate of change)increased with the addition of increasing SMS. Theresistivity index (RI(24)) of the cement with andwithout SMS were comparable.5)The smart cement showed piezoresistive behavior.Addition of SMS reduced the piezoresistive behaviorof the smart cement. Addition of 0.2% SMS did notaffect the compressive strength of the smart cement. AcknowledgementsThis study was supported by the Center for Innovative Grouting Materials and Technology (CIGMAT) at the University of Houston, Texas. Funding for the project (Project No. 10121-4501-01) is provided through the “Ultra-Deepwater and Unconventional Natural Gas and Other Petroleum Resources Research and Development Program” authorized by the Energy Policy Act of 2005. This program—funded from lease bonuses and royalties paid by industry to produce oil and gas on federal lands—is designed to assess and mitigate risk enhancing the environmental sustainability of oil and gas exploration and production activities. RPSEA is under contract with the U.S. Department of Energy’s National Energy Technology Laboratory to administer three areas of research. RPSEA is a 501(c) (3) nonprofit consortium with more than 180 members, including 24 of the nation's premier research universities, five national laboratories, other major research institutions, large and small energy producers and energy consumers. The mission of RPSEA, headquartered in Sugar Land, Texas, is to provide a stewardship role in ensuring the focused research, development and deployment of safe and environmentally responsible technology that can effectively deliver hydrocarbons from domestic resources to the citizens of theUnited States. Additional information can be found at .References1.API Recommended Practice 10B (1997),Recommended Practice for Testing Well CementsExploration and Production Department, 22nd Edition. 2.API Recommended Practice 65 (2002) CementingShallow Water Flow Zones in Deepwater Wells.3.Banthia, N. and Dubeau, S. 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(1997) "Mud ManagementSpecial Slurries Improve Deepwater CementingOperations,” Oil and Gas Journal, Vol. 95, No. 42, pp.49-51.14.Heidari, M., Vipulanandan, C., and Richardson, D.(2013), “Change in Resistance of Modified Oil WellCement with Silica Fume,”Proceedings, CIGMAT -2013,(/sites/cigmat/files/conference/poster/2013/10_2.pdf).15.John B. (1992). “Class G and H Basic Oil WellCements,” World Cement.6 C. Vipulanandan, K. Ali, G. Narvvaez, D. Richardson and J. Pappas AADE-14-FTCE-0516.Kim, J. and Vipulanandan, C. (2006)"Removal ofLead from Contaminated Water and Clay Soil Using a Biosurfactant," Journal of Environmental Engineering, Vol. 132, No. 7, pp.857-865.17.Kim, J. and Vipulanandan, C. (2003) "Effect of pH,Sulfate and Sodium on the EDTA titration of Calcium," Cement and Concrete Research, Vol. 33(5), pp. 621-627.bibzadeh, M., Zhhabizadeh, B., and Khajehdezfuly,A. (2010) "Early Age Compressive StrengthAssessment of Oil Well Class G Cement Due to Borehole Pressure and Temperature Changes,”Journal of American Science, Vol. 6, No.7, pp.38-47.rrondo, L. E., Urness, C. M., and Milosz, G. M.,.(1985) “Laboratory Evaluation of Sodium Hydroxide, Sodium Orthosilicate and Sodium Metasilicate as Alkaline Flooding Agents for a Western Canada R eservoir,” SPE 13577, Phoenix, Arizona.20.Liu, J., Vipulanandan, C., and Richardson, D. (2013),“Piezoresistive Behavior of Modified oil Well Cement with Nickel,” Proceedings, CIGMAT -2013 (/sites/cigmat/files/conference/poster/2013/7_2.pdf)21.Malyshev, A., Doronina, T. Popov, M. andRyabchikov, A.. (2013) “Optimizing Particle Size Distribution Lightweight Cement at low temperatures:Case Study from Eastern Siberia Russi a,” SPE 166849, Moscow, Russia.22.McCarter, W. J. (2006) “Monitoring the Influence ofWater and Ionic Ingress on Cover-Zone Concrete Subjected to Repeated Absorption,” Cement, C oncrete and Aggregates 18.23. McCarter, W. J.and Ezirim H. C. (1998) “Monitoringthe Early Hydration of Pozzolan-Ca(OH)2 Mixtures Using Electrical Methods”[J]. Advances in Cement Research, 10(4): 161-168.24.Mirza, J. et al. (2002) "Basic Rheological andmechanical properties of High Volume Fly Ash Grouts," Construction and Building Materials, Vol.16, pp.353-363.25.Park, J., Vipulanandan, C., Kim, J., and Oh, M. H.(2006) "Effect of Surfactants and Electrolyte Solutions on the Properties of Soils," Journal of Environmental Geology, Vol. 49, pp.977-989.26.Ravi, K. et al. (2007) "Comparative Study ofmechanical Properties of Density-reduced Cement Compositions,” SPE Drilling & Completion, Vol. 22, No. 2, pp. 119-126.27.Ramachandran, V. S. (1984) Concrete AdmixtureHandbook, Noyes Publication, Park Ridge, New Jersey, 628 pp.28.Taylor, M. A. and Arulanandan, K.. (1974)."Relationship Between Elecetrical and Physical properties of Cement paste, Cement and Concrete Research, Vol. 4, pp. 881.29.Thaemlitz, J., A. D. Patel, et al. (1999). "Newenvironmentally safe high-temperature water-baseddrilling-fluid system." SPE Drilling & Completion Vol. 14(3), 185-189.30.Vipulanandan, C. and Prashanth, P. (2013)"Impedance Spectroscopy Characterization of a Piezoresistive Structural Polymer Composite Bulk Sensor,”Journal of Testing and Evaluation, ASTM, Vol. 41, No. 6, pp. 898-904.31.Vipulanandan, C. and Garas, V. (2008) "ElectricalResistivity, Pulse Velocity and Compressive Properties of Carbon Fiber Reinforced Cement Mortar,” Journal of Materials in Civil Engine ering, Vol. 20, No. 2 , pp. 93-101.32.Vipulanandan, C. and Liu, J. (2005) "PolyurethaneBased Grouts for Deep Off-Shore Pipe-in-Pipe Application", Proceedings, Pipelines 2005, ASCE, Houston, TX, pp. 216-227.33.Vipulanandan, C.,and Garas, V. (2006),"Piezoresistivity of Carbon Fiber Reinforced Cement Mortar", Proceedings, Engineering, Construction and Operations in Challenging Environments,”Earth & Space 2006, Proceedings ASCE Aerospace Division, League City, TX, CD-ROM.34.Vipulanandan, C. and Sett, K. (2004) "Developmentand Characterization of Piezoresistive Smart Structural Materials," Proceedings, Engineering, Construction and Operations in Challenging Environments, Earth & Space 2004, ASCE Aerospace Division, League City, TX, pp. 656-663.35.Wang, S. Y. and Vipulanandan, C. (1996)"Leachability of Lead From Solidified Cement-Fly Ash Binders," Cement and Concrete Research, Vol.26, No. 6, pp. 895-905.36.Zhang M., Sisomphon K., Ng T.S, and Sun D.J.(2010). “Effect of superplasticizers on workability retention and ini tial setting time of cement pastes,”Construction and Building Materials 24, 1700–1707.37.Zhang J., Weissinger E.A, Peethamparan S., andScherer G.W. 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(完整word版)新视角研究生英语读说写1(1-6单元习题答案)(word文档良心出品).docx

1.The country is heavily dependent on its oil exports.A. reliant onB. complaint withC. yielding toD.attached to2.An alternative approach is to define words according to the sentence contexts in which they occur.A. outlineB. explainC. specifyD. term3. A second hospital has been accused of mixing up a baby’s name tag , making the mother fear she had the wrong child.A. codeB. paperC. boardD. label4.The director will have to shift his roles and expectations when he’s asked by the rest of the board to answer criticism of company performance.A. moveB. stintC. alterD. transit5.Japanese computer makers are turning to scientists overseas to help them develop software and applications for massively parallel supercomputers.A. heavilyB. immenselyC. solidlyD. ponderously6.There is also evidence that younger people expect to transfer the sourceof their main emotional support to their spouse when they marry.A. move ... toB. subtract ... fromC. distract ... fromD. deflect ... to7.Psychometric tests which attempt to measure students ’ ability to use the library have been developed and made use of primarily in the USA.A. arbitrateB. assessC. calculateD. reckon8.Consequently, the neighborhood they live in, the interests they have, the lifestyle of their friends and colleagues, will necessarily determine whatreality is for the child.A. residential pathB. residential streetC.residential districtD. residential part9.The aim is to help participants identify their own learning needs in this area and then to suggest ways in which they can increase their knowledge.A. affirmB. confirmC. assumeD. recognize10. As we shall see later, they have been one of the factors that have helped to tip the economic balance firmly against the nuclear option.A. tiltB. inclineC. slideD. slant1.Don’t interrupt him. He is now working seriously on his dissertation that is due at the end of this semester.A. buckling down toB. buckling underC. buckling up withD. buckling to2.He has a bad temper and always falls into a fury for the slightest reason, which makes him extremely unwelcome among all the friends.A. sadnessB. depressionC. an extreme angerD. great disappointment3.Through reading the novel, the students realized that the hunchback’s hideous appearance could not conceal his noble characters.A. spectacularB. ugly and unpleasantC. impressiveD.striking and terrible4.When the World War II broke out and the area was bombed severely,many city dwellers had to move to the sticks and led a totally different life.A. small townsB. country areasC. surroundingsD. neighborhoods5.In the general conference, his coarse speaking tone irritated the delegate from the neighboring country and then everyone was involved in a fierce debate.A. ironicB. sarcasticC. angryD. rude6.The police had to keep track of all the actions of the suspects in order to identify the real criminal.A. be informed aboutB. be contacted withC. follow up withD.take notice about7.Confronted with all these evidences and the witnesses, the drunk driver conceded that it was he who caused the fatality of the 3victims in the traffic accident.A. surrenderB. grandC. admitD. yield8.When famine and drought became more severe, the president said he couldnot size up the whole situation and take any action unless he had receiveda complete report.A. bring upB. come up withC. make upD. make a judgment about9.Gaping at the TV screen and watching the fire and smoke,the whole world was startled and could not believe the World Trade Center turned into ruins.A. LookingB. StaringC. GlancingD. Watching10. When thousands of bodies, including those of women and children,were discovered in the forest,everyone and all the media took the same side, criticizing the monstrous mass murder with full bullets.A. tremendousB. incidentalC. famousD. evil读说写 1 第 3 单元1.With a(n) __________ network of committees, sports clubs and societies, each student is encouraged to play a full part in this aspect of student life.A. thrivingB. encouragingC. excitingD. succeeding2.They may pick up ideas almost at random from skimming journals,ideas that may __________ new trains of thought or fruitful new cross-connections.A. steerB. pilotC. sparkD. lead3.Being a good listener is not only useful because you will hear what others miss, but you will find that people will tell you things that they __________ others.A. shield onB. shield fromC. shield inD. shield out4.What right did he have to come back into her life like this,trying to __________ it into small pieces that couldn ’t be put back together for a second time?A. crashB. crushC. shatterD. explode5.In many areas local services were provided by numerous different authorities, which often gave rise to __________ co-ordination problems.A. acuteB. accurateC. accusativeD. alternative6.The awful truth that he was suffering from lung cancer__________him, though his family members tried very hard to keep the secret.A. came uponB. dawned onC. fell toD. went for7.I suppose yoga enthusiasts would find it painless, but for most of us an hour spent in this position was a(n)__________.A. trialB. testC. examD. ordeal8.But rules that strengthen banks in good times can__________them in recessions.A. crippleB. reduceC. slashD. decrease9.There are few more __________ places on earth than the plains surroundinga volcano in the aftermath of its eruption.A. fertileB. unproblematicC. barrenD. unprofitable10. The minds of many of these young offenders appear to have been __________ by greed and indifference to violence.A. retardedB. numbedC. idledD. fooled读说写 1 第 4 单元1.Her reputation suffered a _________ blow as the result of the scandal.A. mortalB. shamefulC. humiliatingD. disgraceful2.In explaining this situation, it might be possible to point to sources _________ to the nation: its culture,mentality, religions, or geography.A. inheritedB. hereditaryC. inherentD. heritable3.His ________ difficulties may make it impossible for him to recognize you and his family.A. perceptualB. appreciableC. understandableD. recognizable4.He had never previously thought of himself as________or even as particularly materialistic.A. inquisitiveB. interactiveC. positiveD. acquisitive5.Like a dreamer, the young artist is absorbed in________of something outside himself and does not identify with it.A. illusionB. contemplationC. conceptionD. fantasy6.The club, where I am staying, releases forgotten gusts of memory,like those lilies which only________ their sweet perfume at night.A. exhaleB. inhaleC. relaxD. relieve7.If it is a technique which works for you then, use it ________.A. by all meansB. by no meansC. in one wayD. by the way8. You would ________ some responsibility immediately for particular areas and additional responsibilities are available to those with the ability andenthusiasm to undertake.A. bear onB. take onC. carry onD. hold on9. This raises the question whether the education of children in rural communities is prejudiced by the________ of a curriculum devised for urban conditions.A. publicationB. compulsionC. computationD. imposition10. The weak point in the school is due to the_________of parents who remove their sons from the school at too early an age.A. follyB. prudenceC. crazinessD. madness读说写 1 第 6 单元1.Even though the Duke was convicted of treason,most of the parliament members still supported him and his book was very popular among the publicA. betrayal of one’s countryB. surrender to the enemyC.hurt to people ’s feelingD. control of others2.This method may seem unorthodox , but it has been proved to be very efficient.A. fitfulB. accidentalC. irregularD. unconventional3.Many people settle down in urban areas instead of the countryside,since it is not time to take a sheer rest and they need to work in cities.A. comfortableB. completeC. relaxingD. permanent4.His voice began to falter at the mention of his sufferings in the old days.A. hesitateB. stutterC. decreaseD. shake5.Politically, Wisconsin is a bit of a maverick, and this nature was firmly established by 1848 when it became a state.A. dissenterB. proponentC. opponentD. extremist6.For over 30 years, Singapore has grown from a poor country with hardlyany resources to an affluent,modern and developed nation.A. abundantB. influentC. wealthyD. stimulant7.The doctor told the single father that his son needed to be coddled after the tuberculosis.A. isolated from othersB. treated with great careC. accompanied by othersD. cured with skill8.As a long-term fancier of the classical music, he spent a lot of money in watching live music concertsA. toastB. collaboratorC. shamblesD. zealot9. The architect said that his countrymen hadn’t learned to cherish the old, and they were too quick to tear old buildings down.A. preferB. treasureC. decorateD. renew10. The proud lady wondered how to lower her pride to approach the girl she had been so scornful of.A. hatefulB. convictedC. contemptuousD. doubtful。

Generation

of anOptimized Code ThecorrectnessGenerationTorb enPoort LangeComputer Science Departmen tyAarh usUniv ersitNovember1992Abstractprogramming language w itha lazy standard s e-Fora functionalby meansofabstract in terpre-mantics,we deﬂnea strictnessanalysisanalysiswe are able ing theinformationfromthestrictnesswhic h a voids dela y ing the ev aluation of the todeﬂnea co degenerationonding function argumen ttoan application,pro vided that thecorrespis strict.To sho w thecorrectnesswe will a dopt theoftheco de generation,and deﬂne a la yerofpredicateswhic h framew orkoflogical relationsis correct withresp e ct to ﬂnally w ill ensure that theco de generationthestandard s eman tics.1In tro ductionprogramming l anguage oneoften co defor a lazy functionalWhen generatingisin terested ingetting themoste–cien t co de,that isa voiding e xp ensiv eofa function f toan instructions.Consider a san example theapplicationargumen t x.If we do notkno w whether theargumen t will be usedby f, we m ust enclose the co defor x with a delay closure(also c alled thunk),th ussho ws dela y ing the ev aluation of x un til n eeded by f.Howev er,if ananalysis1that the argumen t so oner orlater will b eev aluated,wemigh taswell e v aluate it before calling the function f ,sothat wecana void the generation of a dela y closure atall.The information needed canbe obtained froma strictness analysis [1,6,11],whic h wewill d e ﬂnefor the language.The co degenerationtobede ﬂnedwill then usethis information toimpro v e theco de.To pro vethe correctnessof the co degeneration,wede ﬂnea standard seman-tics t ocapture t hemeaning ofexpressions.W e will thende ﬂne a la yerof admissible predicates that ensure t hat thestrictness analysis is correct and that theco degenerated beha vesasexp ected.Section 2will in tro d uceourprogramming language,Section 3de ﬂnesthe in terpretations,Section 4describ estheframew orkfor correctness,Section 5pro vesthecorrectness ofthestrictness analysis and Section 6pro vesthe correctness oftheco de generation.Finally ,Section 7concludes withsome references torelated work.Thispap eris an extended a bstract ofm y M.Sc.-thesis [13],whic h is based on thework[16]and[18]by HanneRiis Nielson andFlemming Nielson.Familiarit y with basic d omain theoretic asp ects (lattices,partial orders,c hains)isassumed,aswell aselemen t ary concepts fromthelam bda calculus and combinatory logic.2The LanguageThe functional language w ill c onsist ofa traditional t yped lam bda calculus toexpress en tities ofcompile-time anda t ypedcombinatory logic toexpress en tities ofrun-time.Underlining will b e used todenote run-time objects.Example The expression e oft ype t 1!t 2willb e a compile-time function from t 1to t 2,whereas e 0oft ype t 01!t02will b e a run-time function from t 01to t 02.When generatingco dewe will c onsider expressions ofthelatter t ype.¥The t ypesare de ﬂnedast ::=A i j t £t j t !t j A i j t £t j t !t 2where A i are someground t ypes,e.g.Bo ol and In t .The syn taxofexpressions ise ::=x i [t ]jf i [t ]jh e;e ij fst e j snde j ‚x i [t ]:e j e (e )jﬂx [t ]e j if e thene el see j F i [t ]j Id [t ]j 2[t ](e ;e )Tupl e [t ](e ;e )j Fst [t ]j Snd [t ]j C ond [t ](e ;e;e )jAppl y [t ]j C ur r y [t ]e j Fix [t ]ewhere f i [t ]denotes a primitiv e function suc h assubtraction ({[In t £In t !In t ])ortesting for zero (isz e r o [In t !Bo ol ]),orconstan tssuc h asin tegers (7[I n t ]).The combinators areclosed l am bda expressionsand thefollo winginformal de ﬂnitions clarify ourin ten tions:⁄[In t £In t !In t ]·‚h x 1;x 2i :x 1⁄x 22[(t 0!t2)!(t 1!t 0)!(t 1!t 2)]·‚f:‚g:‚x:f (g x )Tupl e [(t 0!t 1)!(t 0!t 2)!(t 0!t1£t 2)]·‚f:‚g:‚x:h f x;g x i Appl y [((t 1!t 2)£t 1)!t 2]·‚hf;x i :(f x )C ur r y [((t 0£t 1)!t 2)!(t 0!(t 1!t 2))]·‚f:‚x:‚y:f h x;y i The use ofcombinators will p ro ve useful when de ﬂning an in terpretation for expressions.Example The Miranda TM -lik e factorial functionfac n =1;if n =0=n ⁄fac(n-1),otherwisewith theargumen t n supplied atrun-time is writtenfac =ﬂx (‚f.Cond (Iszer o,1,2(⁄,Tuple (Id,2(f,2({,Tuple (Id,1)))))))where we disp e nse with t ypesfor readabilit y .¥33P arameterized Seman ticsAs we wan t toin terpret thelanguage i ndiﬁeren t wa ys,it is con venien t toofthebasic i ngredients. p ar ameterize theseman tics u pon an in terpretationof t,wheret ype then[[t]](I)will b e thein terpretationIf t is a compile-timetherun-time t ypes.W e ha veI is a function whic h in terprets[[A i]](I)=A i[[t1£t2]](I)=[[t1]](I)£[[t2]](I)[[t1!t2]](I)=[[t1]](I)![[t2]](I)[[t1!t2]](I)=I(t1!t2)pro duct where A i will b ethe atdomain of abase t ype,£forms the cartesianand!forms thecon tin u ousfunction space.is deﬂnedin m uc h the samewa y.To handle The in terpretationof expressionse clauses arewe needan en vironmen t env,sosomeillustrativv ariables[[x i[t]]](I)=‚env:env(x i[t])[[‚x i[t]:e]](I)=‚env:‚v:([[e]](I)env[v x i[t]])[[f i[t]]](I)=‚env I(f i[t])[e1]](I)env)([[e2]](I)env)[[2[t](e1;e2)]](I)=‚env:I(2[t])([It should be clear h o w toextend this deﬂnition tothewhole language. 3.1The StandardSeman tics Sm ustcapture t hein tuitive notion ab outthet ypesand Thisin terpretationinourlanguage.W e deﬂneexpressionsS(A i)=A iS(t1£t2)=(S(t1)£S(t2))S(t1!t2)=(S(t1)!S(t2))anduse liftingbet weene.g.t he undeﬂnedpair andthe pair of todistinguishundeﬂnedelemen t s.4To relate elemen t sfroma domain D with bottomelemen t ?D and domain D ?with bottomelemen t ?we de ﬂne up :D !D ?and dn :D ?!D by8d 2D :up (d )=d 8d 2D ?:up (d )=‰?D if d =?d;otherwiseThe in terpretation ofexpressions is mostly rather s traigh tforw ard.Some ex-amples areS (⁄[t ])=up (‚x:x 1⁄x 2where(x 1;x 2)=dn (x ))S (2[t ])=‚g 1:‚g 2:‰up (‚x:dn (g 1)(dn (g 2)(x )));if g 16=?^g 26=??;otherwise S (C ond [t ])=‚g 1:‚g 2:‚g 3:8>>>><>>>>:up (‚x:8<:dn (g 2)(x );if dn (g 1)(x )=tr ue dn (g 3)(x );if dn (g 1)(x )=fal se ?;if dn (g 1)(x )=?9=;);if g 16=?^g 26=?^g 36=??;otherwiseForthe ﬂx [(t !t )!t ]op erator we m ust restrict ourself tothecases w here t do esnotcon tain an y underlined t ype constructor (t is pur e ),where t hastheform t 1£t 2butis notpure,and ﬂnally w here t hastheform t 1!t2(t is a fr o ntier t ype).The missing c ase is when t =t 1!t 2butnotpure.In this c ase there d o esnotexist a general de ﬂnition,butby making restrictions (e.g.on thewell-formedness rules)we cana void this t ype [15].W e de ﬂneS (ﬂx [(t !t )!t ])=‚G:Fn ‚0G n (?),if t is pureS (ﬂx [(t !t )!t ])=‚G:(G 1;G 2(G 1)),if t =t 1£t 1andnotpurewhere G 1=S (ﬂx [(t 1!t 1)!t 1])(‚x 1:w 1where(w 1;w 2)=G (x 1;G 2(x 1)))G 2=‚x 1:S (ﬂx [(t 2!t 2)!t 2])(‚x 2:w 2where(w 1;w 2)=G (x 1;x 2))The latter de ﬂnition arises froma version ofBeki •c ’s Theorem[2,18].To motiv a tethemissing d e ﬂnition f or fron tier t ypes t =t 1!t2,consider theexpression ‚G:t n ‚0G n (?)whic h isthenatural d e ﬂnition t o usefor5S (ﬂx [(t !t )!t ]).Howev er,when G belongs t o[[(t 1!t 2)!(t 1!t 2)]](S )itislik elythat G (?)=?as we ha ve made thein terpretation strict in?2[[t 1!t 2]](S ),so that t n ‚0G n (?)=G (?)=?whic h isundesirable.Instead,let ususetheelemen t up (?)just ab o ve thebottomelemen t ?and de ﬂneS (ﬂx [(t !t )!t ])=‚G:t n ‚1G n (up (?));if t =t 1!t2whic h is well-deﬂnedas G (up (?))=?implies G (?)=?and S (ﬂx [(t !t )!t ])=?,and G (up (?))A ?implies that (G (up (?)))n ‚1isa c hain.Example The in terpretation of fac by S is Example The in terpretation of fac by S is[[fac ]](S )=‚env :G n ‚1(‚f :up (‚x:‰1;if x =0x ⁄dn (f (x ¡1);if x 6=0 ))n (‚x:?)if S (Isz er o [t ])=up (‚x:x =0)and S (1[t ])=up (‚x:1).¥3.2The Strictness Analysis AThe strictness analysis will b eform ulated a sanabstract in terpretation [1,6].All ground t ypeswill b e in terpreted by thedomain(f 0;1g ;v )with 0v 1,sowe ha veA (A i )=f 0;1g A (t 1£t2)=(A (t 1)£A (t 2))?A (t 1!t 2)=(A (t 1)!A (t 2))?Thein terpretation of expressions is rather standard [1,6,11,16](with resp e ct toour domains),andfor a fewillustrativ ecombinators andop erators weha veA (⁄[t ])=up (‚a:a 1u a 2where(a 1;a 2)=dn (a ))A (2[t ])=‚s 1:‚s 2:8<:up (‚a:dn (s 1)(dn (s 2)(a )));if s 16=?^s 26=??;otherwise6A (C ond [t ])=‚s 1:‚s 2:‚s 3:8>><>>:up (‚a:‰dn (s 2)(a )t dn (s 3)(a );if dn (s 1)(a )=1?if dn (s 1)(a )=0 );if s 16=?^s 26=?^s 36=??;otherwiseA (fix [(t !t )!t ])=‚F:F n ‚1F n (up (?));if t =t 1!t2Example If A (Isxer o [t ])=up (‚a:a )and A (1[t ])=up (‚a:1)we get[[fac ]](A )=‚env :up (‚a:a )sothat fac indeed is a strict function.¥3.3The Co de Generation CThe co de to be generated will be for a stac k based machine.The stac k con tains b ase values s uc h asbooleans a ndin tegers,p airs of the form h v 1;v 2i ,thunks f C;v g topostp o nethe actual ev aluation of C with v onthe top of the stac k,and closur es f C ;v g torepresen tfunctions asdata objects.W e de ﬂne Val tobe theset ofall stac k v alues.The instructions tomanipulate thestac k areins ::=const b j sub j mult j iszero j enter j switch jbranch (C ;C )j tuple j fst j snd j curry (C )j apply jdelay (C )j resume j callrec (l ;C )j call l j recb ::=true j false j 0j 1j 2j¢¢¢The instruction se quenc e C isa mem berof Code ,theset ofall possible mstructlon sequences:C ode =f i 1:i 2:::::i k j k ‚1;i j isan instruction for 1•j •k g [f †g 7The symbol†2C ode denotes t heempt y instructionsequence.seman tics i sdeﬂnedby therelation7!on conﬂgurations. The op erationalareSome example transitions(const b:C;v:ST)7!(C;b:ST)(sub:C;h v1;v2i:ST)7!(C;v1¡v2:ST)(enter:C;v:st)7!(C;v:v:ST)(switch:C;v1:v2:ST)7!(C;v2:v1:ST)(b ranch(C1;C2):C;true:ST)7!(C1:C;ST)(b ranch(C1;C2):C;false:ST)7!(C2:C;ST)(tuple:C;v1:v2:ST)7!(C;h v1:v2i:ST)(delay(C0):C;v:ST)7!(C;f C0;v g:ST)(resume:C;f C0;v g:ST))7!(C0:resume:C;v:ST)(resume:C;v:ST)7!(C;ST),if v is nota th unk(callrec(l;C0):C;ST)7!(C0[callrec(l;C0)=l]:C;ST)\call l"with sequence C[C0=l]is C where ev ery instructionThe instructionsequence C0.a free l ab el\l"is substitutedwith theinstructionExample IfC=enter:call1:resume:tuple:multC0=resume:iszerothen C[C0=l]=enter:resume:iszero:resume:tuple:mult but C[C0=2]=C asthelab el2do esnotoccur in C.callrec(1;C)[C0=1]=callrec(1;C)asthelab elinthein-Furthermore,\call1"in C becomes bound,and callrec(2;C)[C0=1]=structionfree.¥callrec(2;C[C0=1])asthelab el1in C is stillWith exe cution s e quenc e s we mean sequences oftheform¢=(C0;ST0)7!(C1;ST1)7!¢¢¢7!(C i;ST i)7!¢¢¢whic h may beﬂnite o rinﬂnite.W e will w rite¢(i)for(C i;ST i)and¢(i:::)(C i;ST i)7!(C i+1;ST i+1)7!¢¢¢.Furthermore,for thesub-sequencelet usfor ev ery l2f⁄;!;1g[I N deﬂne8E xSeq(⁄)=f¢j¢isﬂnite gE xSeq(!)=f¢j¢is inﬂnite gE xSeq(1)=f¢j¢isﬂnite orinﬂnite gE xSeq(m)=f¢2E xSeq(⁄)j thelength o f¢;#¢,is m gE xSeq(l;C)=f¢2E xSeq(l)j9ST:¢(0)=(C;ST)gE xSeq(l;C;v)=f¢2E xSeq(l)j¢(0)=(C;[v])gsequence C=enter:const3:switch:tuple:sub Example Theinstructiontheexecution sequenceandthestac k ST=[7]initiates¢=(enter:const3:switch:tuple:sub;[7])7!(const3:switch:tuple:sub;[7;7])7!(switch:tuple:sub;[3;7])7!(tuple:sub;[7;3])7!(sub;[(7;3)])7!(†;[4])sothat¢2E xSeq(5) E xSeq(⁄)and¢(5)=(†;[4]).of t ype Since w ewan ttogenerate co defor run-time functions,i.e.expressionst1!t2,it is natural toexp ect C(t1!t2)=C ode?.(Thebottom elemen t?iswe tomake Code a domain.)H owev er,when coming torecursion necessaryfor the lab els,solet usinstead generate r elo c atable c o de, need fresh v ariablesthat is co defromthe domain RelCode=I N!C ode?with the ordering vdeﬂnedbyR C l v R C2()8d2I N:R C1(d)=?_R C1(d)=R C2(d)then isThe t ype part oftheco degenerationC(t1!t2)=[[t1!t2]](A)£RelCodesothat theresultsA are a v ailable.analysisfromthestrictnessco dewe will o bserv e t wo conditions:IngeneratingA:The co de makesno assumptions ab outwhether theinitialv alue on top ofthestac k is a th unk ornot.9B:Iftheexecution oftheco de terminates thenthetopofthestac k willnev erbe a th unk,andexcept f or the topv alue,t he stac ksinthe initial andﬂnal con ﬂgurations will b e thesame.When expressing correctness of the co degeneration with resp e ct tothe stan-dardseman tics w e will s ho w that these conditions are observ ed.Consider theclause for ⁄[t ]:C (⁄[t ])=(A (⁄[t ]);‚d:resume:enter:snd:resume:switch:fst:resume:tuple:mult)The ﬂrst resume instruction is duetocondition A ,andthe mult instruction ensure that we do notlea v e a th unk on thestac k (condition B ),sothat it isnotnecessary toterminate theinstruction sequence w ithan additional resume instruction.Thisis similar toa co de generation withno strictness analysis [18].When lo oking at 2[(t 0!t 2)!(t 1!t 0)!(t 1!t 2)]we canusethe strictness information togenerate sligh tly better c o de:C (2[t ])=‚(s 1;R C 1):‚(s 2;R C 2):(s;R C )where s =A (2[t ])(s 1)(s 2)R C =‚d:8>><>>:‰R C 2(d ):R C 1(d );if dn (s 1(?)=?delay (R C 2(d )):R C 1(d );otherwise ;if R C 1(d )6=?^R C 2(d )6=??;otherwiseIf the ﬂrst argumen t expression to 2[t ]is strict (i.e.dn (s 1)(?)=?),we can disp e nse with the delay instruction,unlik e inthesimple c o degeneration.Concerning t he ﬂx [(t !t )!t ]op erator i nthecase of t =t 1!t 2,we calculate thestrictness information by ignoring theco de,sothatC (ﬂx [(t !t )!t ])=‚F:(s;R C );if t =t 1!t2where s =t n ‚1(‚s 0:(w 1where (w 1;w 2)=F (s 0;¢)))n (up (?))10R C =‚d:‰callrec (d;C d );if C d 6=??;otherwiseC d =(w 2where (w 1;w 2)=F (s;‚d 0:call d ))(d +1)The dot\¢"in F (s 0;¢)is a shorthand for the relo catable instruction sequence ‚d:?.W e will l ater see that sis indep e nden t ofthe actual c hoice o finstruc-tion sequence,sothat an y instruction sequence would be feasible.Example Ifwe de ﬂne C (Isz er o [t ])=(up (‚a:a );‚d:resume :iszero )and C (1[t ])=(up (‚a:1);‚d:const 1)we get[[fac ]](C )=‚env :(up (‚a:a );‚d:callrec (d;C ))whereC =enter:resume:iszero:branch (const 1,enter:delay(e nter:delay(const 1):switch:delay(resume):tuple:C :calld):switch:delay(resume):tuple:C ⁄)C =resume:enter:snd:resume:switch:fst:resume:tuple:sub C ⁄=resume:enter:snd:resume:switch:fst:resume:tuple:mult Our analysis detects thestrictness ofsubtraction,m ultiplication and the recursiv e call,and we areth us able toa voidthegeneration ofa delay in-struction around theco defor theﬂrst argumen t toall 2[t ]-com binators.¥4Correctness usingPredicatesInorder toexpress t hecorrectness ofthestrictness analysis and theco de generation,we will adopttheframew orkof lo g ic a lr elations [20,21]and Kripke-lo gic a lr elations [21,22].Deﬂnition1(F rom [17])An indexed relation overtheinterpr etations I 1;:::;I m is a c ol le c tion o fr elations11R t:[[t]](I)£:::£[[t]](I m)!f tr ue;fal se g onefor e achtyp e t.It is a logicalrelationif andonly ifR t1!t2(f1;:::;f m)·8(x1;:::;x m):R t1(x1;:::;x m))R t2(f1(x1);:::;f m(x m))holds for al ltyp e s t1and t2.A Kripk e-indexed relationover a non-empty p artiallyor der e d set›andthe interpretations I1;:::;I m is a c ol le c tion o fr elationsR[§]t:[[t]](I1)£:::£[[t]](I m)!f tr ue;fal se gonefor e achtyp e t,wher e8§0w§:R[§]t(x1;:::;x m))R[§0]t(x1;:::;x m)holds foral l typ e s t.Itisa Kripk e-logicalrelationif and only if itisa Kripke-indexed r elation andR[§]t1!t2(f1;:::;f m)·8§0w§:8(x1;:::;x m):R[§0]t1(x1;:::;x m))R[§0]t2(f1(x1);:::;f m(x m))holds for al ltyp e s t1and t2.When coming totheﬂx[t]-op erator it is necessarytoensure t he admissibility ofourpredicates.Deﬂnition2A pr e dic a te R on the domain D is admissibleif1.R(?)holds.2.If(d n)n is a chain on D and R(d n)holds,then R(t n(d n)n)holds.To sho w that the relationshold we will u se the principleofstructuralinduc-tion.Deﬂnition3(F rom[17])An indexe d r elation R over I1;:::;I m admit structuralinductionwhenever i t satisﬂes,that if12R t0([[`]](I1);:::;[[`]]I m))holds for al lb asic op er ators and c ombinators`oftyp e t’o c curring i nan expr e ssion e oftyp e t,thenR t([[e]](I1);:::;[[e]]I m))holds.A Kripke-indexed r elation R over›and I1;:::;I m admit structuralinduc-ﬂes,that iftion whenever i t satisR[§]t0([[`]](I1);:::;[[`]]I m))holds for al l§2›andfor al lb asic op er ators andc ombinators`oftyp e t’o c cuning inan expr e ssion e oftyp e t,thenR[§]t([[e]](I1);:::;[[e]]I m))holds.W e no w ha vegic a l r elationsadmitaswel lasKripke-loFact4(F rom[17])Lo gic a l r elationsalinduction.structurwing.This fact will b e utilizedinthefollo5Correctness ofthe Strictness Analysisin C is correct with resp e ctcollectedinformationTo verify that the strictnessval A t for t run-time and tothe standard seman tics,wedeﬂnet wo predicates:tforw ard:The deﬂnitions are quite s traighcompA t for tcompile-time.val A t:[[t]](A)£[[t]](S)!f tr ue;fal se g(a;x)·x6=?)a=1val A Ai13val A t1£t2(a;x)·x6=?)(a6=?)^val A t1(a1;x1)^val A t2(a2;x2) 1;a2)=dn(a);(x1;x2)=dn(x)val A t1!t2(s;g)·g6=?)(s6=?)^(8a;x:val A t1(a;x))val A t2(dn(s)(a);dn(g)(x)))W e seethat8a:val A t(a;?)and8x:val A t(>;x)bothhold,i.e.ev ery abstract v alue describestheseman tic v alue?and ev eryseman tic v alue is describedby thetopelemen t oftheappropriateabstract domain.compA t:[[t]](C)£[[t]](S)!f tr ue;fal se gcompA Ai(x;y)·x=ycompA t1£t2((x1;x2);(y1;y2))·compA t1(x1;y1)^compA t2(x2;y2)compA t1!t2(F;G)·8x;y:compA t1(x;y))compA t2(F(x);G(y))compA t1!t2((s;R C);g)·val A t1!t2(s;g)Lemma5The clauses for c ompA deﬂne an admissiblepr e dic a te.Proof A simple s tructuralinductionon thet ype t.¥The correctnessofthestrictnessanalysis no w amoun tsto sho wing that compA holds for all basic o p erators andcombinators.Proposition6The pr e dic a te compA t([[e]](C);[[e]](S))holds f or every expr e s-sion e oftyp e t.Proof As c ompA is a logicalrelationwe only needtoconsider eac h combi-nator and op erator(F act4).It is quite s traightforw ard,see e.g.[13],solet usonly consider theop eratorﬂx[(t!t)!t]inthecase t=t1!t2. Assume compA t!t(F;G),deﬂnes n=(‚s0:(w1where(w1;w2)=F(s0;¢)))n(up(?))g n=G n(up(?))andlet usby inductionon n sho w that148R C:compA t((s n;R C);g n)(P n)y of compA.The base case n=0is immediate b y admissibilitUsing(P n)and compA t!t(F;G)we get compA t(F(s n;¢);G(g n)),butg n+1=G n+1(up(?))=G(g n)ands n+1=(‚s0:(w1where(w1;w2)=F(s0;¢)))(s n)=w1where(w1;w2)=F(s n;¢)whic h completes thepro of,since c ompA t((s n;R C);g n)·val A t(s n;g n)and y of compA.¥by admissibilitisinformation oftheab o ve pro of,we see that thestrictnessAs a corollaryofﬂx[t]by C,infact, indep e nden t oftheco de,sothat thein terpretationmake sense.is[1,4],where a suit-analysisof a strictnessOther approac hes tocorrectnessho wev er,is just a nother function is deﬂned.The predicates,able abstractionfunctionﬁt:if whenev er val A t(a;x)also wa y ofdeﬂning suc h an abstractionprop erties ofan abstrac-ﬁt(x)v a,thenﬁt would resp e ct the c haracteristiction function.6Correctness ofthe Co de Generationed by awill consist ofthree la yers,eac h describThe pro ofofcorrectness,thesecond predicate.Theﬂrst la yerensures t hatﬂx[t]isusedcorrectlyensures that the generated co debeha veswell o n the stac k, la yeradditionallyanalysis and,ﬂnally,thelast la yerensures thecorrectnessofthestrictness andthegenerated co de.need toincorp orate t he This approac h is similar to[18],butwe additionallypredicate.This will,aswe shall s ee, analysisin tothecorrectnessstrictnesscause no di–culties.156.1The Substitution Propert yThisprop ert y isneeded toguaran t eethat theco de forﬂx[t]will only be applied t ofunctionsthat may be regarded a srelo catable co de withholes. First,deﬂnecompS0[§]t:[[t]](C)£[[t]](C)!f tr ue;fal se gcompS0[§]Ai(x;y)·x=ycompS0[§]tt£t2((x1;x2);(y1;y2))·compS0[§]t1(x1;y1)^compS0[§]t2(x2;y2)compS0[§]tt!t2(F;G)·8§0¶§:8x;y:compS0[§0]t1(x;y))compS0[§0]t2(F(x);G(y))compS0[§]t1!t2((s1;R C1);(s2;R C2))·8d>max(dom( )):compS00[§]t1!t2(R C1(d);R C2(d))where comps00[§]t1!t2(C1;C2)·(C2=?)C1=?)^(C26=?)(C16=?)^C1[§]=C2^F r eeLab(C1) dom(§)) The function Fr e eL ab:Code!f D j D I N g collectsthefree lab els inan instructionsequence.The parameter§,denoting a substitution,is a set of pairs o flab els andco de.With dom(§)we mean the set f l j(l;C)2§g,and whenev er(l;C1)2§and(l;C2)2§then C1=C2.Lemma7The clauses for c ompS’[§]deﬂne an admissiblepr e dic a te. Proof A simple s tructuralinductionon thet ype t.¥The desired prop ert y can no w be stated a s the Substitution P ropert y [15,18]:Proposition8Assume that compS0[§]t!t(F0;F)holds for every typ e t= t1!t2andthat for d>max(dom(§))andevery s2[[t]](A)we have deﬂne d C=(w2where(w1;w2)=F(s;‚d0:call d))(d+1)C0=callrec(d;C)C00=(w2where(w1;w2)=F(s;‚d0:C0))(d+1)ThenC6=?)C[C0=d]=C00^F r eeLab(C0) dom(§)16holds.\call l"may The prop osition sa ysthat the\hole"in C(the instructionC00.safely be substitutedwith C0yieldingProof Assume C6=?,deﬂne C0using F0inthesamewa y as C is deﬂned using F,andconsider thet wo stages1and2.Stage1:Extend§to§1=§[f(d;call d)g.FromcompS0[§2]t((s;‚d0:call d);(s;‚d0:call d))we get compS0[§1]t((¢;‚d0:C0);(¢;‚d0:C))sothat F r eeLab(C) dom(§)[ f d g and C=C0[§].Stage2:to§2=§[f(d;C0)g.FromcompS0[§2]t((s;‚d0:cal ld);(s;‚d0:C0))we get compS0[§2]t((¢;‚d0:C0);(¢;‚d0:C00))so that C00=(C0[§])[C0=d]= C[C0=d]whic h completes thepro of.¥tobe able to W e only needtosho w that compS0holds for ev eryexpressionuseProp osition8:Proposition9The pr e dic a te compS0[§]t([[e]](C);[[e]](C))holds for every§andevery expr e ssion e oftyp e t.it is su–cien trelationProof As the predicatecompS0[§]is a Kripk e-logicaltosho w that compS0[;]t([[e]](C);[[e]](C))holds.F orev eryop erator a nd com-tforw ard,for theﬂx[t]op erator w e binator o ther thanﬂx[t]this isstraighmimicStage1ofProp osition8.¥;and iden t ical argu-As we only use compS0withan empt y substitutioncompS t:[[t]](C)!f tr ue;fal se g byrelationments,let usdeﬂne thelogicalcompS t(x)·compS0[;]t(x;x)andusethis deﬂnition inthefollowing.176.2The W ell-b eha vednessPredicateTo ensure that theco de only transformsthetopelemen t ofthestac k in to another w ell-beha vedelemen t,weuse the val W and compW predicates.The val W predicateensures thewell-beha vedness o fa stac k elemen t:val W t:V al!f tr ue;fal se gval W Ai (b)·tr ue for all basic v alues b oft ype Aival W t1£t2(h v1;v2i)·val W t1(v1)^val W t2(v2)val W t1!t2(h C;v0i)·8v1:val W t1(v1))val W t2(f C;h v0;v1i g)val W t(f C;v g)·8¢2E xSeq(⁄;C;v):postW t(¢)^nothunk(¢) The predicatepostW tells uswhether a co de sequence¢ends with a well-beha vedelemen t on the stac k,and nothunk ensures that the last e lemen t on thestac k is nota th unk.postW t;nothunk:E xSeq(m)!f tr ue;fal se gpostW t(¢)·9v:¢(m)=(†;[v])^val W t(v)nothunk(¢)·:9C;C0;v;ST:¢(m)=(C;f C0;v g:ST)The deﬂnition of val W t(f C;v g)sa ys,that if we execute C with v on topof thestac k,we endup with a well-beha vedelemen t on thestac k whic h is not a th unk.The well-beha vedness p redicatecompW t:[[t]](C)!f tr ue;fal se g is deﬂned asfollows:compW Ai(x)·tr uecompW t1£t2((x1;x2))·compW t1(x1)^compW t2(x2)compW t1!t2(F)·compS t1!t2(F)^(8x:compW t1(x))compW t2(F(X)))compW t1!t2((s;R C))·compSW t1!t2((s;R C))^(8d>0:compSW t1!t2(R C(d)))where compSW t1!t2(C)·C6=?)(8v2V al:val W t1(v))val W t2(f C;v g))18Lemma 10The clauses for c ompW deﬂne an admissible pr e dic a te.Proof First w e m ust de ﬂnea well-founded order …on t ypesandv alues b y(t 1;v 1)…(t 2;v 2)()(t 1is a prop ersubt y pe of t 2)_(t 1=t 2^v 1isnota th unk ^v 2is a th unk)Consider t heneac h clause f or val W t (v ).If v isnota th unk,theneac hval W t 0(v 0)on therigh t hand side has(t 0;v 0)…(t;v )since t 0isa subt y pe of t .If v is a th unk,thenwe ha ve val W t 0(v 0)on therigh t hand side with t =t 0,but v 0is nota th unk by nothunk ,so(t 0;v 0)…(t;v ).As the predicate val W no w is well-de ﬂned,the admissibilit y of compW is aneasy structuralinduction on thet ypes.¥W e are no w ready tosho w that compW holds for all op erators and combi-nators.Proposition 11The pr e dic a te compW t ([[e ]](C );[[e ]](S ))holds for every ex-pr ession e oftyp e t.Proof Even though compW is nota logical relation,it is an instance ofa Kripk e -la yered predicate whic h admits structural induction [17].Therefore,for eac h op erator orcombinator,consider an execution sequence¢2E xSeq (m;C 1:C 2:::::C k )anddecomp oseit in toexecutionsequences ¢i (m i ;C i )for i 2f 1;:::;k g .Then either use the induction hypothesis on ¢i orwrite ¢i outindetail toget the desired result.A full p ro ofofwell-b eha vedness c anbe found in[18],yetfor a simpler co degeneration.¥6.3The Correctness PredicateForrun-time objects we de ﬂne val C t :V al £[[t ]](S )!f tr ue;fal se g asfol-lo ws:val C A i (b ;x )·val W A i (b )^B i [[b ]]=x val C t 1£t 2(h v 1;v 2i ;x )·9x 1;x 2:x =up (x 1;x 2)^19val C t 1(v 1;x 1)^val C t 2(v 2;x 2)val C t 1!t 2(f C ;v 0g ;g )·val W t 1!t 2(f C ;v 0g )^(g 6=?)^(8v 1;x :val C t 1(v 1;x ))val C t 2(f C;h v 0;v 1i g ;dn (g )(x )))val C t (f C;v g ;x )·val W t (f C;v g )^val W C t (f C;v g ;x )where val W C t ·8¢2E xSeq (1;C;v ):(¢2E xSeq (!))x =?)^(¢2E xSeq (⁄))postC t (¢;x )^nothunk (¢))The function B i :V al ![[A i ]](S )maps a basic v alue to its appropriate coun terpart inthestandard s eman tics.F oran example,B bool (true )=true and B int (7)=7.The predicate postC is de ﬂnedm uc h as postW ,theonly di ﬁerence b eing an additional parameter t otheseman tic v alue and using val C instead of val W .W e omitthedetails.Finally ,we de ﬂne compC t :[[t ]](C )£[[t ]](S )!f tr ue;fal se g by thefollo wing clauses:compC A i (x;y )·x =ycompC t 1£t 2((x 1;x 2);(y 1;y 2))·compC t 1(x 1;y 1)^C ompC t 2(x 2;y 2)compC t 1!t 2(F;G )·compW t 1!t 2(F )^compA t 1!t 2(F;G )^compW C t 1!t 2(F;G )where comp W C t 1!t 2(F;G )·8x;y :compC t 1(x;y ))compC t 2(F (x );G (y ))compC t 1!t 2((s;R C );g )·compW t 1!t 2((s;R C ))^compA t 1!t 2((s;R C );g )^(8d >0:compW C t 1!t 2(R C (d );g ))where comp W C t 1!t 2(C;g )·(C =?)g =?)^(C 6=?)g 6=?^(8v;x :val C t 1(v;x ))val C t 2(C;v;dn (g )(x ))))Before c on tin u ing with the pro of of correctness,wem ust besure the predicate is well-de ﬂned.Lemma 12The clauses for c ompC deﬂne an admissible pr e dic a te.Proof Similar tothepro ofofLemma 10,this is a structural induction on thet ype t .¥20。

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考研英语高频词汇1.a host of = a lot of 大量2.abandon = give up 放弃3.absence 没有，不存在4.abide by = obey; comply with, conform to 遵守5.ab normal ities 不正常6.absolute of: relative; com parative 绝对的7.absor ption 吸收，理解8.abstract of: concrete 抽象的；摘要9.abundance—abundant ly=rich (ness) 充足；大量10.ab use滥用11.accelerate—acceleration =speed up 加速12.access to—access ible 接近；获得13.accommodate—accommodation 提供食宿；以适应14.accomplish ment =achievem ent 成就，圆满完成15.account for 解释；占据百分比16.ac count ant 会计17.accumulat ion 积累18.accura cy—accura te 精确性19.ac know ledge 公认、承认20.acquaint ance 熟人；熟悉（with）21.acquir e—acqui sition—acqui sitive 获得；学会；习得；合并22.act on 对…起作用23.act ively 积极地；主动地24.adapt to 适应25.addict 上瘾26.address 称呼；强调27.adjoin 毗邻28.adjust 调节29.admir ation 景仰；崇拜30.admi ssion 录取；允许进入；门票31.adopt 领养；采纳32.adventur ous 冒险的；历险的33.advis ability—advis able—advis or—advi s ory 可取性—值得建议的—建议者—指导性的34.advocate 支持；拥护（者）35.affiliate 附属36.affinity 关系；酷爱37.afford 买得起；承受得起代价38.agenda 议事日程39.agent 代理人；主体40.aggravate=worsen 恶化41.aggressive 挑衅的，好斗的；积极进取的42.aging 衰老的43.agony （身心的）极大痛苦44.aid=help45.aim目标46.alien to 不相容的；与…相反的47.align with 与…一致48.all but=almost49.alleg ation 陈述；声称50.allocat ion 分配，拨给（款项）51.allow for 把…考虑在内52.alone 仅就…而言53.along one track 顺着某一做事方式54.alphabet—alphabet ically 字母表—按字母表顺序的55.alter 改变（衣服大小和容貌）56.alternative—alternative ly 选择；可供选择的—可供选择地57.am ateur 业余的58.am azed—amaz ing 惊异的—令人惊异的59.am biguous 容易引起歧义的；模棱两可的60.am bition 雄心；野心61.amid=in the middle of62.am ount to=reach 达到；到达63.am ple 大的；充足的64.analogous 类似物，近似物65.analys is—analyst 分析66.ancestor 祖先67.anchor 抛锚；停泊68.angle 角度69.announce 宣告70.anonymous 匿名的71.anticipate=expect72.anxi ety 焦虑73.anything but=not at all 一点也不74.apart from=besides 除…以外还有75.apparatus 设备；装置76.apparent—apparent ly 明显地77.appeal to=attract 吸引78.appli ance—appli cable—appli cation 用具；器具—申请；应用79.appreciate 欣赏；理解；感激80.apprehensive 忧虑的81.approach 途径；接近82.appropriate 合适的；恰当的83.arbiter 权威人士；仲裁员84.arbitrary 武断的；刚愎自用的85.arriv al 到达86.articulate 明确而有力地表达87.artist ic 艺术的88.aspired 有灵感的89.assault=attack 袭击90.assem ble =get together 集合；组装91.assert 断言；声称92.assess—assess able 评估93.assign 安排；布置94.assimilate—assimilat ion 同化95.assist—assist ance =help 帮助96.assum e—assum ption= take on 假设；承担；呈现97.assure 使某人确信98.astonish ing 令人震惊的99.at a loss =confused 迷惑的100.at random 随机地101.at the m ercy of 任由某人处置102.at will 任意地；随意地103.attach importance to 强调；重视104.attain 达到；获得105.attempt 企图；试图106.attendance—attentive to 关注107.attitude 态度108.attribute to 把…归因于109.auditor 审计员；查帐人110.augment 扩大；增加；提高111.authentic 地道的112.authority—authori ze 权威—授权113.autom ate 自动化114.auxiliary 辅助的115.average 普通的；平均的116.a wake n 唤醒；唤起117.aware 意识到；知道118.awkwardly 尴尬地119.baby boom 婴儿潮120.back bone 栋梁；中坚121.bait 鱼饵，诱饵122.ban 禁止123.bank on 寄希望于124.barely 几乎不125.bargain 讨价还价；便宜货126.barrier 障碍127.baseline 底线128.be absorbed in 全神贯注于129.be bound up with 某事物关系密切130.be com posed of 由…组成131.be confined to 局限于132.be engaged in 从事于133.be fascinated with 被…迷住了134.be indicat ive of 表明135.be obliged to 被迫做某事136.be opposed to 反对137.be rooted in 以…为根源138.bear able 可以忍受的139.belt 带状物140.benefi cial—benefit 有好处的—利益；对…有好处141.betray 背叛142.better off 经济状况变得更好143.beyond dispute毋庸质疑144.bias 偏见145.bilingual 双语的146.bill 法案147.bind ing 受法律约束的148.bio medical 生物医学的149.bitter 苦涩的，激烈的150.blind 盲目的151.block 阻碍152.bold 大胆的；冒进的153.bomb ard…with 攻击某人/物154.bonus 奖金；意外的好处155.boom热潮156.booth 电话亭157.bore 使厌烦158.bound 注定；装订159.boundary 边界160.brake 刹车；阻碍因素161.brand 品牌162.break down 崩溃163.break through—breakthrough突破164.breakout 爆发165.breed 种；血统；滋生166.bright ening 照亮的167.bring out 产生168.bring under control 控制住169.broad ly 从广义上说170.brochure 小册子171.broker 经纪人172.bubble 冒泡；充满喜悦之情173.budget 预算174.build up 建立175.bulk 大块；大量176.bunch 一束；一簇177.burden some 造成负担的178.bureaucracy 官僚机构179.business 事务180.by a large margin 以较大差距赢利181.bypass 偏路182.byproduct 副产品183.call for 要求184.call on 拜访185.call up 打电话；召集186.cam paign （没有硝烟的）战争187.candidate 候选人188.canteen 食堂189.cap ability—cap able 能力—能干的190.capacity 能力；容量191.capital—capital ism首要的/资本—资本主义192.captive—capture 俘虏—捕获193.care free 无忧无虑的194.carry out 实现；完成195.carry weight 有影响；有份量；有力196.casual—casual ly 随意地197.cater to 迎合，满足198.caution—cauti ous—cauti ously 小心；谨慎199.cease =stop 停止200.cem ent 水泥；巩固，加强201.census 人口普查202.central ization—central ize 中央集权化203.chain 连串；连锁店204.chair 主持205.channel 频道；渠道206.characteristics 特征207.cheery 喜气洋洋的208.chief ly 主要地209.child bearing 生孩子210.chip 薄片；芯片；电脑211.circ uits 电路；封闭线路212.circ umstance 条件213.citizen ry 公民身份214.civil—civil ization—civil ize 国内的—文明—使文明215.claim—claiming声称（对…具有所有权）216.clash 冲突217.class—class ify类别—分类218.classic 古典的；经典的219.clear-cut 明确的220.client 当事人；顾客221.climbing ladder 升职路径222.cling to 附着223.clinics 诊所224.clone 克隆；复制225.cluster 簇；丛/ 聚集226.code 方式227.co incidence 巧合228.collapse 坍塌229.col league 同事230.colony 殖民地 bat 战斗；对抗 e into being形成 e on 进步；成长mand 掌握；精通mercial—commercial ized商业的；广告—商业化mi ssion—commit—commit ment 佣金；回扣—犯（罪，错误）modity 商品munity 一个群体mute 通勤（固定往返于两地之间） pany 陪伴par ative—compar ison 比较而言的—比较passion ate 有同情心的 pel=force 强迫 pensate—compensat ion=make up弥补；补偿petent ly能干地 petition—competiti veness—co mpeti tor竞争—竞争激烈—竞争者 pile编撰plement ary补充的 ponent组成成分 prehension 理解 prehensive 全面的，综合的 press 压缩 pulsion—com pulsive 强制254.concept=idea 观念；概念255.concern担心，关心256.concise简洁的257.conclu sive结论性的258.concrete具体的259.con dense 浓缩260.conduct—conductive行为；进行，实施261.confer—confer ence商讨；授予—会议262.confess承认（坏事）263.confide泄露秘密264.con firm进一步证实265.conflict冲突266.conform—conform ity to 遵守；符合267.confront—confront ation面对；面临268.confus ion迷惑269.connotation 言外之意270.conscious有意识的271.consensus共识272.consent同意273.consequen ce—consequen t—conse quen tly结果—因此的—因此274.conserv ation—conserv ative保护；保守—保护的；保守的275.consider ably相当大地，相当多地276.consist—consist ently包含—前后一致地277.con solid ation巩固；加强278.conspicuous 明显的279.constitute—constitut ional组成—合乎宪法的280.construct = build建造281.consult ant—consult ation 咨询专家282.contem plative深思熟虑的；沉思的283.contem porary当代的；同时代的284.contem pt—contempt ible轻视；蔑视—可鄙的285.contend—conten tion 主张；争辩286.context上下文；环境（抽象）287.continu ally—continu ous 断断续续的—连续不断的288.contract合同；收缩289.contradict—contradict ion—contrad ict ory 矛盾，对立，反驳290.contrari ly 相反291.contribute—contribut ing导致，造成292.controversial 有争议的293.convention—convention al常规—常规的294.convey= express表达295.convince—convinc ing使确信—有说服力的296.co operation—co-operative 合作—具有合作精神的297.coordinate—coordinat or 协调—协调员298.cope对付299.corporate—corporat ion 团体的，联合的—公司300.cor relation相互联系301.correspond—correspond ing一致；通信—有联系的302.cost ly昂贵的303.council市议会，市政厅304.counsel劝告，忠告/ 法律顾问305.counter balance—counter part平衡力，起平衡作用—相对应的人或物306.courage ous 无畏的，勇敢的307.course路线；课程308.cover the cost支付费用309.craft工艺310.creat ionism—creat ivity 创造主义—创造性311.credi bility可信度312.crisis危机313.criteria标准314.critical—critical ly—criticize—critics 评论—批评的，关键的—批评地，关键地—批评家315.crop收获，收割316.crucial关键的317.cruel ty残忍318.cultivate—cultivat ion培养319.cure治愈；疗法320.custom ary—custom ize习惯的，惯例的—顾客化（按顾客意见做）321.cut and dried 过分简洁的322.cut off 切断323.cute 可爱的324.cycle 周期325.data base 数据库326.dazzl ingly 令人目眩地327.deal with 处理；和…有关328.dece ptive 欺骗性的329.declar ation 宣告330.decline 下降；拒绝331.dedicate 有献身精神的332.deduce 演绎；推断333.deem=t hink 认为；相信334.deep en深化335.defeat打败336.defect ive有问题的337.defend—defend ant—defend er防御；辩护—被告—后卫338.defer ence 尊重，遵从，服从，顺从339.define—defin ition 下定义—定义340.definitely 确定无疑地341.de grad ation 降级342.delay =hold up耽误343.deliberately= on purpose 故意地344.delicate脆弱的，易损的345.deliver—deliver y送货；发言的方式技巧346.dem and要求；需求347.democra cy—democra tic 民主—民主的348.dem ographer人口学家349.dem onstrate—demonstrat ion=show 表明350.dense ly populated人口稠密的351.deny否认；否决352.depend ent upon依靠353.depict=describe 描写，描绘354.depletion削减；消耗355.depress ion抑郁症；经济萧条356.derive from=com e from; result from 来自357.descend ant子孙后代358.desert沙漠；遗弃359.deserve理应得到360.desir able称心如意的361.despair—desperate绝望—不顾一切的362.detach of: attach 分离363.destin y 命运364.destr uction 毁灭365.detect ing 探测的366.determine—determin ism决定—决定论367.deteriorate 恶化368.detrimental =harmful 有害的369.de value d 贬值的370.devised 设计的371.devote 贡献372.die out 消亡373.differ—d iffer entiation不同—差异；区别对待374.diffuse 消散375.digi tal 数字的；数码的376.dignity 尊严377.dilute 稀释378.dimension 空间；维度379.di mini sh 逐渐变小；逐渐消失380.direct ory 电话簿381.dis able 残疾382.dis advantaged 处于劣势的383.discard 抛弃384.discern 辨别；识别385.discipline 纪律；学科386.dis comfort 不舒适387.dis connect 断开连接388.dis content with不满意；不满足389.discourse 话语390.dis cover y 发现391.discriminat ion歧视；鉴别；区别392.dis grace d 丢脸的393.disguise 伪装394.dis honest 不诚实395.dis honor 丢脸396.dis integrate 分解；瓦解；崩溃397.dis junction 不交汇398.dis order 无序；紊乱399.dis organize d无组织的400.disparaging贬低性言语401.dis passion无激情402.disperse 驱散403.dispute争执404.dis regard漠视，不关心405.dis satisfaction 不满意406.dis solve 溶解407.distant 遥远的408.dis taste for 无品味409.distinct ion—distinct ly 区别；明显地410.distinguish fro m区别411.distort歪曲；扭曲412.dis tract使分心413.dis trust 不信任414.diverse—diversity多元的，多样的—多元化，多样化415.diver sion 偏离，转向416.divi sive 造成分裂的417.do one’s bid 努力418.doctrine 教义419.dom e 圆顶420.dom estic 国内的；家庭的421.dominant—dominate占主导地位的—主导，支配422.doom注定；劫数423.dos age—dose 剂量424.down scale 裁员425.down shifting 下降趋势426.down size 裁员427.doze off 打盹428.draft 草稿，初稿429.drama tic—drama tically—drama tize 戏剧性地—戏剧性的—戏剧化430.draw from 从中提取431.draw up 草拟；制订432.draw back 缺陷，不足433.dread—dread ful 可怕；可怕的434.drift 漂流435.driving force 驱动力436.drop out 中途退出437.dubious ly 怀疑地，犹豫地438.dull 笨拙的；沉闷的439.duplicat ion=copy 复制440.dur able 耐久的441.dwell 居住，详细讨论，总是考虑442.dynamic 动态的443.eager ness 热心，渴望444.effect 影响；导致—效果445.effort less 毫不费力的446.e labor ate 详尽的447.electronic—electronics电子的—电子学448.elegant 优雅的449.elevate 抬起，举起，升高450.eliminate—eliminat ion 消除451.elite—elit ism精英—精英主义452.em ber 余烬453.em brace 拥抱，包含；体现454.em erge—emerge nce 出现455.em ergency 紧急情况456.eminent =outstanding; remarkable; fam ous457.emit 发出，散发458.emphasi s 重点459.en counter 遇见460.en danger 使有危险461.endeavor 努力462.end less 无尽的463.ends 目的464.endure 忍受465.energ etic 精力充沛的466.enhance加强，增强467.en light en 启发468.en list注册；招募469.enquir y 询问；调查470.en rich 使丰富471.en sure 确保472.entail 使…成为必要473.enterprise 事业；企业474.entertain er 娱乐者475.en throne 使就任；提拔476.enthusiastic 热心的，热情的477.entire ly 完全地478.entitle 使有权做某事479.entrepreneur 企业家480.envy 嫉妒481.epidemic 流行性的482.episode 片断483.epithet 描述性短语484.equa te…with 等同于485.equi valent 相等的486.essen tial 必要的487.ethical—ethics 道德的488.even ly 均匀的489.eventual ly =in the end最终的490.evolutio nary—evolve 进化的，发展的—进化，发展491.exaggerat ion 夸张492.exceed 超过except for—except ion—exception al 除了—例外—格外的493.excessive过多的，过度的494.ex change交换，交流495.executive行政管理的（人员）496.exemplify 举例说明497.exercise 行使498.exert 强加499.exhaust 耗尽500.exotic 来自外国的501.expan sion 扩充502.expect ation 期望503.expla natory 解释性的504.explicit ly 明确地505.exploit ation 开发、利用506.explos ion—explosive 爆炸—爆炸性的507.expose—expos ure暴露508.express ive表达能力强的；富有表现力的509.extend—extend ed family 延伸—大家庭510.ex ternal外部的511.extinct灭绝512.extinguish熄灭513.extravagantly奢侈的514.fabric结构515.fabricate锻造，伪造516.fact ual事实的；真实的517.faculty才能；教职工；学院518.fade—fad ing 褪色，逐渐消失519.faith fully 忠诚地；忠实地520.fall short of 不足521.fall victim to 成为牺牲品522.fam e 名声523.fanci ful—fancy富于幻想的—想象524.far from一点也不525.farfetched牵强的；夸张的526.far-reaching（影响）深远的527.fascinat ion魅力528.fashion 时尚529.fat 丰厚的530.fatal 致命的531.feature特色532.federal联邦制的533.fertile肥沃的；多产的534.fever ishly心急如焚的535.fiction小说536.fierce强烈的537.figure数字538.finance 财政；提供资金539.find fault with挑剔540.finite 有限的541.fix 修理；固定542.flat 扁平的；断然的543.flaw 瑕疵；缺陷544.flee =escape 逃跑545.float 漂浮546.flourish繁荣；昌盛；兴旺547.fluctuate波动548.focus 焦点549.for the sake of为了…的缘故550.forbid禁止551.force fully—force强有力地—力552.formulate —form ulation制订；确切表达—公式；确切表达553.forsake 放弃554.fortune 运气；发财555.forum 论坛556.fraction 一部分557.fram e 框架558.freight （运输）货物559.frenzy 极度狂热560.frequent ly 经常561.frown 皱眉；反对562.fruit ful—fruitless 富有成果的563.frustrate—frustrat ion 挫败564.fuel 燃料；加燃料，促进565.fulfill 实现566.function—function al 功能；起作用567.further 进一步；推进568.futur ist 未来学家569.gamble 赌博570.gender 性别571.general ization 归纳572.gene rate—generat ion—genetic ally 产生—代—从基因来看573.geological—geology 地理的—地理学574.get stuck 卡住，陷入不动575.giant 巨大的576.gigantic 巨大的577.give birth to 产生，导致578.give rise to 产生，导致579.give thought to 考虑某事580.glimpse 一瞥581.global ization 全球化582.gloomy 阴郁的；不景气的583.glowing 热烈的584.go off 变质/ 爆炸585.gold rush 淘金热586.good-for-nothing 无用的人587.good ness 善良，美德，精华ern 统治589.grand 宏伟的590.granted 被批准的591.graph 图表592.grasp 抓住；理解593.gravity 重力594.greedy 贪婪的595.griev ance 悲痛596.grip 紧抓住597.gross 总的598.guarantee 保证，担保；质保599.guard against 防御，抵制，防止600.guid ance—guide line 指导—指南601.guilt y 有罪的；内疚的602.habit ual 习惯性的603.halve (half) 对半分；减半604.handicap 残疾；不足605.handle = deal with 处理606.harbor 港口；庇护607.harmoni ous 和谐的608.harness 利用609.hasten 使匆忙610.haunt 萦绕611.have one’s way 自有一套612.head line 头条613.head-scratch ing 令人头疼的614.heavi ly 程度深地615.heighten 提高616.heritage 遗产（文化）617.hesitate 犹豫618.high light 强调619.hinder 阻碍620.histor ian 历史学家621.hold back 阻止；抑制；克制622.hold on 坚持623.hook 钩子；钩住624.horizon 地平线；眼界；（知识的）范围625.horrify 令人害怕626.hospitality 好客627.host 男主人；男主持人628.hostil ity—hostile 敌意629.house hold 家庭630.human e—human ity 仁慈的—人性631.humble 谦卑的，谦恭的632.humiliation 不光彩；耻辱633.husbandry 农牧业634.hyper active 多动的635.identical 一模一样的636.identif iable—identify识别；辨别637.ideology 意识形态638.ignor ance—ignor ant 无知；不知道639.ill-treat 虐待640.illuminating 富有启发性的641.illustrate 举例说明642.imagin ation—imagi native 想象力—富有想象力的643.imitate 模仿644.immense 巨大的645.immigrant 移民646.im moral 不道德的647.immune to —immun ization对…有免疫力—不受影响648.impact （深远的）影响649.im part ial 公正的，不偏袒的650.im patien t 不耐烦的651.imperative 必要的，强制性的652.impetus 推动；刺激；促进653.implement ation 实施654.impli cation 外之意655.implicit 暗示的656.im polite 不礼貌的657.impose 强加658.im pover ished 使贫困659.im practical 不切实际的660.im prison 囚禁661.im proper 不恰当的662.im pulse冲动；刺激；推动力663.in brief 总而言之664.in case 万一665.in contrast with/to 和…形成对比、相反666.in despair 绝望地667.in effect =in fact 事实上668.in favor of 支持，赞成669.in honor of 为了纪念…;为了表示敬意670.in no time 立刻；马上671.in no way 不同意672.in one wave after another 一批接一批673.in proportion (to)和…成比例674.in quest of 寻求，搜寻675.in question 正被考虑或讨论676.in return 作为回报677.in the face of 面对某事；不顾678.in the light of 鉴于，考虑到。