The Golden Gate Bridge had the longest suspension bridge span in the world when it was completed in 1937 and has become an internationally recognized symbol of San Francisco and California.Since its completion,th

“明天我們?nèi)タ唇痖T橋，”彼得說，“我從來沒有見過金色的橋?！北说玫母赣H微笑著并沒有說什么。彼得很快就會看到那座橋了。第二天早上，父親帶著彼得去那座橋。它看起來是多么大呀！而且這座橋是紅色的?！八⒉皇且?/p>

the city is a truly beautiful thing to see.金門大橋看起來非常美，而海灣大橋是適合觀賞景色的美麗橋梁。晚上，舊金山大樓的燈會亮起來，從海灣大橋看上去，這座城市真的很漂亮。

The Golden Gate Bridge (這個大橋叫“金門大橋”）The Golden Gate Bridge is a suspension bridge spanning over 1,280 meters to connect San Fransisco to the surrounding northern Californian counties. The bridge was

介紹金門橋英語短文帶翻譯

土木工程的英文是Civil Engineering ,直譯是民用工程,它是建造各種工程的統(tǒng)稱。它既指建設的對象,即建造在地上,地下,水中的工程設施,也指應用的材料設備和進行的勘測,設計施工,保養(yǎng),維修等專業(yè)技術。土木工程隨著人類社會的進步而發(fā)展,至

we first study the application of the protection pipe sliding method for the construction. This paper introduces the protection pipe outside sliding method installation "steel set of directly buried steam pipeline s

3.3.2 in the assembly process, the class and group leaders and assembly should carefully read the map and record important data, processes, and installation of pipelines to the scope, found problems in a

與成本控制,最重要的決議的質(zhì)量,在設備完成設計和規(guī)劃階段,而不是在施工期間。正是在這種初步階段,即組件配置、物料規(guī)范和功能性能決定。施工過程的質(zhì)量控制,由大量的確保符合原先的設計和規(guī)劃的決定。

Construction Safty:Safty in construction is the most important item in all construction items. it covers all the safty matters during the operation, including management, finance and logistic system et al.The gove

Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works such as bridges, roads, canals, da

我們比以往任何時候更多地依賴于團隊建設承包商和發(fā)明人誰設計和建造以及維護復雜的環(huán)境，環(huán)繞著我們的日常生活。一個民間的施工隊伍的工作/工程師以上僅僅是這些基礎設施建設方面。他們有很多活動，包括起草，決策，人機交互，通

求一篇施工方面文章及英文翻譯 謝

請各位英文高手幫我翻譯一個句子,謝謝啦! Every body knows the principle:a mistake every one will make often--a rainbow will tell you in the sky after being rainy,"fet yourself,get more. " 我是意譯高手,不喜死譯。我

then I picked it up.It turned out to be a purse.Immediately,I gave it to the policaman because I was in a hurry to school.At 10pm,

1、We are ready to do our best to help the poor mothers 2、Our Community will pay the cost of Bill's coming to college.3、That secondary school have built a laboratory for the students.4、Our college

他怎么能救那孩子在罐子里？然后他很快地工作的危險。突然他想到了一個好主意。他被石頭撞罐子放在一邊。很快他犯了一個大洞，在大罐。立刻，水沖出罐子，孩子得救了。

but particularly in the first two or three years. Mathematics is very important in all branches of engineering,so

急急急!請英語高手幫我翻譯一篇英文,要人工的,謝謝了,回答的好的話還可以加分哦

翻譯:建筑類型和設計建筑物與人們有著緊密的聯(lián)系,他為人們提供必要的空間,用以工作和生活。根據(jù)適用類型不同,建筑物可以分為兩類:工業(yè)建筑和民用建筑。工業(yè)建筑包括各個工廠或工業(yè)生產(chǎn)所使用建筑,民用建筑是指那些人們用以居住,就業(yè),教育

If You Build It …People say the government should be run more like a business. So imagine yourself as CEO. Your bridges are crumbling. Your air-traffic control system doesn’t use GPS. The Society of

On these will hinge the future property acquisitions and settlements made by the right-of-way agents. 由地段權政府代表做出的今后所有權的獲得和結算都將依此而定。Large-scale topographic maps or other special

a large number of new entrants making a relatively large number of engineering consulting firm, and the annual increase rapidly, out of less. Engineering

Engineering has been an aspect of life since the beginnings of human existence. Civil engineering might be considered properly commencing between 4000 and 2000 BC in Ancient Egypt and Mesopotamia when humans started

土木工程是一個概念，涉及的設計，建造和保養(yǎng)身體和自然的建筑環(huán)境。民間建筑和工程的行為，包括橋梁，道路，運河， **，水壩和其他建筑物。這些都只是僅是民用建設工程，是幾個例子。土木工程是最古老的工程后，軍事工程學科

Engineersconsider many factors when developing a new product. For example, in developing an industrial robot, engineers precisely specify the functional requirements; design and test the robot抯 components; integrate

求1000字左右的土木工程英語文章 帶翻譯的

Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including works such as bridges, roads, canals, dams and buildings. Civil engineering is the oldest engineering discipline after military engineering, and it was defined to distinguish non-military engineering from military engineering. It is traditionally broken into several sub-disciplines including environmental engineering, geotechnical engineering, structural engineering, transportation engineering, municipal or urban engineering, water resources engineering, materials engineering, coastal engineering, surveying, and construction engineering. Civil engineering takes place on all levels: in the public sector from municipal through to federal levels, and in the private sector from individual homeowners through to international companies. History of civil engineering Civil engineering is the application of physical and scientific principles, and its history is intricately linked to advances in understanding of physics and mathematics throughout history. Because civil engineering is a wide ranging profession, including several separate specialized sub-disciplines, its history is linked to knowledge of structures, materials science, geography, geology, soils, hydrology, environment, mechanics and other fields. Throughout ancient and medieval history most architectural design and construction was carried out by artisans, such as stone masons and carpenters, rising to the role of master builder. Knowledge was retained in guilds and seldom supplanted by advances. Structures, roads and infrastructure that existed were repetitive, and increases in scale were incremental. One of the earliest examples of a scientific approach to physical and mathematical problems applicable to civil engineering is the work of Archimedes in the 3rd century BC, including Archimedes Principle, which underpins our understanding of buoyancy, and practical solutions such as Archimedes' screw. Brahmagupta, an Indian mathematician, used arithmetic in the 7th century AD, based on Hindu-Arabic numerals, for excavation (volume) computations. 土木工程是一門學科，專業(yè)工程的設計，施工和維護自然的物理和環(huán)境建設，包括橋梁，道路，河渠，堤壩和建筑物的工程協(xié)議。土木工程是最古老的軍事工程后，工程學科，它被定義為區(qū)分軍事工程非軍事工程。這是傳統(tǒng)分解成若干子學科包括環(huán)境工程，巖土工程，結構工程，交通工程，市政工程或城市，水資源工程，材料工程，海岸工程，測量，施工工程。土木工程需要在所有層次上進行：在從市政公用部門通過聯(lián)邦的水平，并在私營部門，個別業(yè)主通過向國際公司 土木工程的歷史 土木工程是物理和科學原理的應用，它的歷史是錯綜復雜的聯(lián)系在物理學和數(shù)學的了解整個歷史的進步。由于土木工程是一個廣泛的行業(yè)，包括一些獨立的專門的子學科，它的歷史是聯(lián)系在一起的結構，材料科學，地理，地質(zhì)，土壤，水文，環(huán)境，機械和其他領域的知識。 在整個歷史上最古老的和中世紀的建筑設計和施工進行了如石匠和木匠手藝，上升到建筑師的角色。知識是保留在很少的行會和進步所取代。構筑物，道路和基礎設施存在的重復，并在規(guī)模上升的增量。 對科學方法的物理和數(shù)學問題適用于土木工程最早的例子之一是阿基米德在公元前3世紀，包括阿基米德的原則，鞏固我們的浮力的認識，如阿基米德螺旋切實可行的解決辦法的工作。婆羅門，印度數(shù)學家，用在公元7世紀算法的基礎上，印度教，阿拉伯數(shù)字，挖掘（卷）計算。
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如果這是一份非常非常重要的文件, 那么樓主還需要再精雕細琢一下, 畢竟我也不是native speaker 找同學什么的再改一改. 另外 身體真的很重要啊!!! 革命的本錢不能亂揮霍噠~~ 希望你早日康復咯~ Cheers, 小胖同學 I am really honored that you gave me this working opportunity before. If it was not for you, I think I shall never have a chance to get involved in this area. When asked for leaving at first, not only did you persuade me to stay, but had me move to a non overtime-working group. I thank you from the bottom of my heart. During that time I promised myself that I would work hard not to disappoint you. But due to my physical condition, I disappoint you anyway. To be honest I am really hoping to work on this position. But today my long-term illness relapsed again. I was in deep stomach pain this morning at work. Doctor suggested I should stay in hospital for future recovery. I am feeling deeply guilty for not accomplishing your work and alongside the trouble I brought to you. Since my mother will come and look after me next week, I could still work this week. Again I apologize for all the inconvenient, and again, thank you very much.
早起在很多方面都很有好處。我們都需要新鮮空氣，但是任何時候的空氣從來不會比早晨的空氣更新鮮。除此以外，晨練也是很有好處的。 第二，早起可以為一天的工作制定計劃。沒有一個好計劃，我們是不能很好工作的。 第三，早起讓我們有充足的時間為工作做準備。比如洗臉，洗手，吃早餐。 晚起的人們可能覺得形成早起的習慣很困難。他們需要付出很大的努力才能做到。正如英語諺語所說“早睡早起讓一個人健康，富有，聰明”。
Health care A new prescription for the poor 為貧窮者新開的處方 America is developing a two-tier health system, one for those with private insurance, the other for the less well-off 美國正在發(fā)展一個雙重的健康系統(tǒng)，一重是為那些有個人保險的人群，而另一重則是為那些不那么富裕的人群 Oct 8th 2011 | NEW YORK | from the print edition “IT’S time for Dancing with the Stars!”, a woman announces enthusiastically. At this New York health centre, wedged between housing projects to the east and Chinatown to the west, “dancing with the stars” means dancing with a physical therapist. An old man stands up with a nurse and begins a determined samba. “是時候和明星一起跳舞了！”一位女士滿懷熱情地宣告。在這個坐落于房屋工程的西面，唐人街東面的紐約健康中心，“和明星起舞”的意思是和一位物理治療師跳舞。一位老者和一個護士站起來，開始跳事先確定好的桑巴舞。 Comprehensive Care Management (CCM), which runs this centre, tries to keep old people active. To do so, explains Joseph Healy, the chief operating officer, is in the company’s best interest. The government pays CCM a capped rate for the care of its members. If someone gets sick, his health costs rise and the company’s margin shrinks. Mr Healy argues that the system is the best way to provide good care at a low cost. Increasingly others seem to agree. 經(jīng)營這個中心的綜合護理管理部門（CCM）努力保持老人們的活力。約瑟夫-海莉，首席運營官解釋說，這樣做符合公司 的最佳利益。政府給這個部門一個封頂?shù)慕蛸N來讓他們照顧這些人。如果有人生病了，他的健康成本就會上升，公司的利潤就會萎縮。海莉先生確定說這個系統(tǒng)能夠 在一個低成本上提供最佳的護理。其他人也逐漸同意這個觀點。 Medicaid, America’s health programme for the poor, is in the process of being transformed. Over the next three years, New York will move its entire Medicaid population into “managed care”, paying companies a set rate to tend to the poor, rather than paying a fee for each service. New York is not alone. States from California to Mississippi are expanding managed care. It is the culmination of a steady shift in the way most poor Americans receive their health-care treatment. 公共醫(yī)療補助，即美國的窮人健康計劃，正在被改造的過程中。在接下來的 三年內(nèi)，紐約將把整個接受窮人健康計劃的人群納入“管理關懷”之中，付給公司們一個事先定好的費用來照顧那些窮人，而不是按照項目來付費。紐約不是唯一這 樣做的州。加州，密西西比州正在拓展管理關懷計劃。這代表一種正在進行中的穩(wěn)步轉(zhuǎn)變，即大部分貧窮美國人接受健康關懷方式的轉(zhuǎn)變。 Medicaid is America’s sin*** biggest health programme. This year roughly one in five Americans will be covered by Medicaid for a month or more. It gobbles more federal and local money than any state programme, other than education. Costs will rise even more when Barack Obama’s health-care reform expands the programme by easing eligibility rules in 2014. Congress’s “supercommittee” is already considering cuts. However, there are more immediate pressures behind the present drive for change. 公 共醫(yī)療補助是美國最大的單一健康計劃。今年，五個美國人中的一個就會被納入該計劃一個月或更長時間。除了教育之外，它比其他任何州的財政計劃耗去更多聯(lián)邦 和地方的經(jīng)費。當2014年奧巴馬的健康保險改革放寬適用人群而使整個計劃更加龐大的時候，成本將會進一步上升。眾議院的“超級委員會”已經(jīng)在考慮削減經(jīng) 費。然而，選擇這種變化，將會有更多即刻的壓力存在。 Enrolment in Medicaid jumped during the downturn, from 42.7m in December 2007 to 50.3m in June 2010. Mr Obama’s stimulus bill helped to pay for some of this, but that money has dried up. Faced with gaping deficits, some desperate governors slashed payments to hospitals and doctors, or refused to pay for trips to the dentist or oculist. But much the most important result has been structural: the expansion of managed care. 公共醫(yī)療補助計劃的參與人數(shù)在經(jīng)濟滑坡期間從2007年 12月的 4270萬人跳到了2010年6月的5030萬人。奧巴馬先生的經(jīng)濟刺激經(jīng)費能夠幫助付掉其中的一部分，但是錢已經(jīng)被用光。面對資金短缺，一些絕望的州長 砍掉了給醫(yī)院和醫(yī)生的補助，或是拒絕支付牙醫(yī)和眼科醫(yī)生的旅行費用。但是，更多地，最重要的結果是結構上的：管理關懷的拓展。 States have dabbled in managed care for decades. The trend accelerated in the 1990s, with the share of Medicaid patients under this form of care reaching 72% by 2009. Now, however, there is a strong push for the remainder. States that did not have managed care, such as Louisiana, are introducing it. Other states are extending it to people previously deemed off limits: California and New York, for example, are moving the elderly and disabled into that system of care. Texas is targeting more than 400,000 Medicaid beneficiaries in the Rio Grande Valley. Local politicians had resisted the move, nervous that care might deteriorate. But the yawning deficit meant that they were overruled. 各個州涉足管理關懷已經(jīng)有幾 十年的歷史了。這個趨勢在90年代得到**發(fā)展，在2009年前使用這種護理方式的公共醫(yī)療補助病人占到了72%?，F(xiàn)在，對于剩下的人，這也是很強的推動 力。像路易斯安那州這樣沒有管理關懷的州正在引進管理關懷。其他州也把這個拓展到原先被認為不適用的人群：舉例說像加州和紐約州，正在把老人和殘障人士納 入這個系統(tǒng)中，德州的目標是在格蘭德河谷超過400000公共醫(yī)療補助收益人群。地方政治家反對這個舉動，他們擔心這個護理系統(tǒng)將會變質(zhì)。但是巨大的赤字 意味著他們的觀點注定要被批駁。 The result is a country with two distinct tiers of health care. Most Americans with private insurance are still horrified by thoughts of health-management organisations and prefer to pay fees for each medical service. For the poor, managed care is becoming the norm. 結果就是一個國家有兩套截然不同的健康保險系統(tǒng)。大多數(shù)有個人保險的美國人仍舊害怕那些健康管理組織的想法而寧愿為單獨的醫(yī)療服務付費。對于窮人來說，管理關懷已經(jīng)成為一種常規(guī)。 Advocates of managed care have high expectations. First, they hope that it will make costs more predictable. Second, they believe that the change will improve patients’ health. In managed care, a patient has a network of doctors and specialists. If the programme works properly, doctors can monitor all aspects of care, in contrast to the fragmented fee-for-service system. The contracts that states have with firms can set standards for quality. Texas, for instance, will cut 5% from a company’s payment if it does not meet what is required. 管理關懷的鼓吹者有著很高的 期待。首先，他們希望這能讓成本變得可以預測，其次，他們相信，這個改變可以改善病人的健康。在管理關懷中，一個病人有一個由醫(yī)生和專家組成的網(wǎng)絡。如果 這個計劃運行良好，醫(yī)生可以監(jiān)測關懷的各個方面，相對于分離的的按服務付錢的系統(tǒng)來說。州政府和公司的合同可以為質(zhì)量定下標準。德州，舉例說，將會在付款 中扣除5%如果公司沒有達到要求的標準。 The next step is to integrate care for those eligible for both Medicaid and Medicare, the federal programme for the old. These “duals” account for almost 40% of Medicaid’s costs and just 15% of its population. “If managed care can really deliver better care than fee-for-service”, says Diane Rowland, chair of the commission that advises Congress on Medicaid, “this is the population that could prove it.” 下一步是整合那些同時符合公共醫(yī)療補助和長者醫(yī)療補助計劃（聯(lián)邦老人醫(yī)療補助）的人群。這些“雙符合”人群占據(jù)了將近40%的公共醫(yī)療補 助成本和僅僅15%的人口數(shù)量?！叭绻芾黻P懷能真正比按項目付費帶來更好的服務”，戴安-羅蘭德，委員會（指導國會在公共醫(yī)療補助政策上進行決策）主任 說：“這是一群能證明管理關懷可行的人?！? But some, such as Norma Vescovo, are sceptical. As the head of the non-profit Independent Living Centre of Southern California (ILCSC), Ms Vescovo serves Medicaid patients with severe health problems. Over the years she has often sued California on policies that she thinks will hurt her vulnerable clients. On October 3rd her case moved to the Supreme Court. 但是一些人，例如像諾瑪-凡斯科夫就對此表示懷疑。作為非盈利的南加州獨立生活中心主任，凡斯科夫女士服務于那些有嚴重健康問題的接受公共醫(yī)療補助的病人。在這些年間，她經(jīng)?？馗婕又菡谝恍┱呱蠒λ囊恍┐嗳醯目蛻?。在10月3日，她的案子被移到了上訴法院。 The outcome of Douglas v Independent Living Centre will have profound implications for the future of Medicaid. Ms Vescovo’s suit concerns cuts to hospitals and doctors. But the case will also guide the course of managed care. If ILCSC and its co-plaintiffs win, private groups will continue to be able to challenge states on policies they think violate federal Medicaid law. Ms Vescovo, who argues that California’s payment cuts would eviscerate her clients’ access to services, worries that under managed care the disabled might not be able to see the specialists they need. 道格拉斯 v 獨立生活中心的結果將會對公共醫(yī)療補助有深遠的意義。凡斯科夫女士的訴訟影響到醫(yī)院和醫(yī)生的津貼削減。但是這個案子將會引領管理關懷的進程。如果中心和其 他原告勝訴，私人團體將會繼續(xù)在那些他們認為違反聯(lián)邦法律的政策上挑戰(zhàn)州政府。凡斯科夫女士認為說加州的支付削減計劃會讓她的客戶失去得到服務的機會，她 還擔心，在管理關懷之下，那些殘障人士可能不能見到那些他們需要的專家。 The question is how to supervise the experiments with managed care that are being carried out in various states. To date, Medicaid beneficiaries have been able to challenge the states in court. However, if the Supreme Court rules against ILCSC, that avenue will be closed. The Centres for Medicare and Medicaid Services (CMS) technically can intervene if states do not provide proper access to care. In reality, CMS has few tools to do so. 問 題是怎么監(jiān)管在不同州試運行的管理關懷。到目前為止，公共醫(yī)療補助受益者已經(jīng)能夠在法庭中挑戰(zhàn)政府。然而，如果上訴法庭結果不利于中心，那么這條路將會被 關閉。如果州政府沒有提供合適的關懷的話，公共醫(yī)療補助和長者醫(yī)療關懷中心理論上是能對此進行干涉，但事實上，他們沒有太多辦法。 “I’m a big fan of managed care”, says Sara Rosenbaum, a professor at George Washington University, “but this transformation may happen with almost no federal oversight.” Medicaid beneficiaries are vulnerable, in worse health than Americans as a whole. Companies may strug*** to cut costs and provide good care as well. If states do not draft their contracts properly, or fail to be vigilant in monitoring patients’ health, their experiment in managed care could be a disaster. On the other hand, if states are careful they could provide an answer to the question that has vexed America for years: how to provide good, cheap health care. “我是 管理關懷的擁護者”，薩拉-羅森博姆，一位喬治華盛頓大學教授說，“但是這種轉(zhuǎn)變可能在沒有聯(lián)邦監(jiān)管的情況下發(fā)生?！惫册t(yī)療補助的受益者和你脆弱，健康 程度整體上比一般美國人要差。公司可能在削減成本的同時掙扎著同樣提供良好的服務。如果州政府們不好好起草他們的合同，或沒有警覺地監(jiān)控病人的健康的話， 他們在管理關懷上的實驗可能會是一場災難。另一方面，如果州政府們認真的話，他們能為那個困擾美國人多年的問題提供答案，即怎么提供優(yōu)質(zhì)的便宜的健康關 懷。
Electric Power Systems 電力系統(tǒng) The modern society depends on the electricity supply more heavily than ever before. 現(xiàn)代社會的電力供應依賴于更多地比以往任何時候。 It can not be imagined what the world should be if the electricity supply were interrupted all over the world. 它無法想象的世界應該是什么，如果電力供應中斷了世界各地。 Electric power systems (or electric energy systems), providing electricity to the modern society, have become indispensable components of the industrial world. 電力系統(tǒng)（或電力能源系統(tǒng)），提供電力到現(xiàn)代社會，已成為不可缺少的組成部分產(chǎn)業(yè)界的。 The first complete electric power system (comprising a generator, cable, fuse, meter, and loads) was built by Thomas Edison – the historic Pearl Street Station in New York City which began operation in September 1882. 第一個完整的電力系統(tǒng)（包括發(fā)電機，電纜，熔斷器，計量，并加載）的托馬斯愛迪生所建-站紐約市珍珠街的歷史始于1882年9月運作。 This was a DC system consisting of a steam-engine-driven DC generator supplying power to 59 customers within an area roughly 1.5 km in radius. The load, which consisted entirely of incandescent lamps, was supplied at 110 V through an underground cable system. 這是一個半徑直流系統(tǒng)組成的一個蒸汽發(fā)動機驅(qū)動的直流發(fā)電機面積約1.5公里至59供電范圍內(nèi)的客戶。負載，其中包括完全的白熾燈，為V提供110通過地下電纜系統(tǒng)。 Within a few years similar systems were in operation in most large cities throughout the world. With the development of motors by Frank Sprague in 1884, motor loads were added to such systems. This was the beginning of what would develop into one of the largest industries in the world. In spite of the initial widespread use of DC systems, they were almost completely superseded by AC systems. By 1886, the limitations of DC systems were becoming increasingly apparent. They could deliver power only a short distance from generators. 在一個類似的系統(tǒng)在大多數(shù)大城市在世界各地運行數(shù)年。隨著馬達的弗蘭克斯普拉格發(fā)展在1884年，電機負載被添加到這些系統(tǒng)。這是什么開始發(fā)展成為世界上最大的產(chǎn)業(yè)之一。在最初的直流系統(tǒng)廣泛使用盡管如此，他們幾乎完全被空調(diào)系統(tǒng)所取代。到1886年，直流系統(tǒng)的局限性也日益明顯。他們可以提供功率只有很短的距離從發(fā)電機。 To keep transmission power losses ( I 2 R ) and voltage drops to acceptable levels, voltage levels had to be high for long-distance power transmission. Such high voltages were not acceptable for generation and consumption of power; therefore, a convenient means for voltage transformation became a necessity. 為了保持發(fā)射功率損失（我2 R）和電壓下降到可接受的水平，電壓等級，必須長途輸電高。如此高的電壓不發(fā)電和電力消耗可以接受的，因此，電壓轉(zhuǎn)換成為一個方便的手段的必要性。 The development of the transformer and AC transmission by L. Gaulard and JD Gibbs of Paris, France, led to AC electric power systems. 在發(fā)展的變壓器，法國和交流輸電由L.巴黎戈拉爾和JD吉布斯導致交流電力系統(tǒng)。 In 1889, the first AC transmission line in North America was put into operation in Oregon between Willamette Falls and Portland. 1889年，第一次在北美交流傳輸線將在俄勒岡州波特蘭之間威拉梅特大瀑布和實施。 It was a sin***-phase line transmitting power at 4,000 V over a distance of 21 km. With the development of polyphase systems by Nikola Tesla, the AC system became even more attractive. By 1888, Tesla held several patents on AC motors, generators, transformers, and transmission systems. Westinghouse bought the patents to these early inventions, and they formed the basis of the present-day AC systems.這是一個單相線路傳輸功率為4,000公里，超過21 V系統(tǒng)的距離。隨著交流的發(fā)展多相系統(tǒng)由尼古拉特斯拉，成為更具吸引力的。通過1888年，特斯拉舉行交流多項專利電動機，發(fā)電機，變壓器和輸電系統(tǒng)。西屋公司購買了這些早期的發(fā)明專利，并形成了系統(tǒng)的基礎，現(xiàn)在的交流。 In the 1890s, there was considerable controversy over whether the electric utility industry should be standardized on DC or AC. By the turn of the century, the AC system had won out over the DC system for the following reasons: 在19世紀90年代，有很大的爭議或交流電力行業(yè)是否應該統(tǒng)一于直流。到了世紀之交的，在交流系統(tǒng)贏得了原因出在下面的直流系統(tǒng)為： （1）Voltage levels can be easily transformed in AC systems, thus providing the flexibility for use of different voltages for generation, transmission, and consumption. （1）電壓水平可以很容易地改變了空調(diào)系統(tǒng)，從而提供了傳輸?shù)撵`活性，發(fā)電用不同的電壓和消費。 （2）AC generators are much simpler than DC generators. （2）交流發(fā)電機簡單得多比直流發(fā)電機。 （3）AC motors are much simpler and cheaper than DC motors. （三）交流電機和電機便宜簡單得多，比直流。 The first three-phase line in North America went into operation in 1893——a 2,300 V, 12 km line in southern California. 前三個階段的美國北線投產(chǎn)于1893年- 1 2300五，南加州12公里路線研究。 In the early period of AC power transmission, frequency was not standardized. 在電力傳輸初期交流，頻率不規(guī)范。 Many different frequencies were in use: 25, 50, 60, 125, and 133 Hz. 有許多不同頻率的使用：25，50，60，125，和133赫茲。 This poses a problem for interconnection. Eventually 60 Hz was adopted as standard in North America, although 50 Hz was used in many other countries. 這對互連的問題。最后60赫茲標準獲得通過，成為美國在北美，雖然是50赫茲在許多其他國家使用。 The increasing need for transmitting large amounts of power over longer distance created an incentive to use progressively high voltage levels. To avoid the proliferation of an unlimited number of voltages, the industry has standardized voltage levels. In USA, the standards are 115, 138, 161, and 230 kV for the high voltage (HV) class, and 345, 500 and 765 kV for the extra-high voltage (EHV) class. In China, the voltage levels in use are 10, 35, 110 for HV class, and 220, 330 (only in Northwest China) and 500 kV for EHV class . 較長的距離越來越需要大量的電力傳輸多激勵他們逐步使用高壓的水平。為了避免電壓增殖數(shù)量無限，業(yè)界標準電壓水平。在美國，標準是115，138， 161，和230千伏的高電壓（高壓）類，345，500和765千伏級的特高電壓（超高壓）。在中國，各級使用電壓為10，35，110級高壓， 220，中國330（僅在西北）和500千伏超高壓類。 The first 750 kVtransmission line will be built in the near future in Northwest China. 第一個750 kVtransmission線將建在不久的將來在中國西北地區(qū)。 With the development of the AC/DC converting equipment, high voltage DC (HVDC) transmission systems have become more attractive and economical in special situations. 隨著交流的發(fā)展/直流轉(zhuǎn)換設備，高壓直流高壓直流（HVDC）傳輸系統(tǒng)已經(jīng)成為更具吸引力的經(jīng)濟和情況特殊。 The HVDC transmission can be used for transmission of large blocks of power over long distance, and providing an asynchronous link between systems where AC interconnection would be impractical because of system stability consideration or because nominal frequencies of the systems are different. 在高壓直流輸電可用于輸電塊以上的大長途電話，并提供不同系統(tǒng)間的異步連接在AC聯(lián)網(wǎng)系統(tǒng)將是不切實際的，因為穩(wěn)定考慮，或因標稱頻率的系統(tǒng)。 The basic requirement to a power system is to provide an uninterrupted energy supply to customers with acceptable voltages and frequency. 基本要求到電源系統(tǒng)是提供一個不間斷的能源供應，以客戶可接受的電壓和頻率。 Because electricity can not be massively stored under a simple and economic way, the production and consumption of electricity must be done simultaneously. A fault or misoperation in any stages of a power system may possibly result in interruption of electricity supply to the customers. 由于電力無法大量儲存在一個簡單的方法和經(jīng)濟，電力的生產(chǎn)和消費必須同時進行。系統(tǒng)的故障或誤操作的權力在任何階段可能導致電力供應中斷給客戶。 Therefore, a normal continuous operation of the power system to provide a reliable power supply to the customers is of paramount importance. 因此，一個正常的電力系統(tǒng)連續(xù)運行的，提供可靠的電力供應給客戶的重要性是至關重要的。 Power system stability may be broadly defined as the property of a power system that enables it to remain in a state of operating equilibrium under normal operating conditions and to regain an acceptable state of equilibrium after being subjected to a disturbance. 電力系統(tǒng)穩(wěn)定，可廣泛定義為干擾財產(chǎn)的權力系統(tǒng)，可繼續(xù)經(jīng)營的狀態(tài)下正常運行的平衡條件和后向遭受恢復一個可以接受的平衡狀態(tài)。 Instability in a power system may be manifested in many different ways depending on the system configuration and operating mode. 在電力系統(tǒng)的不穩(wěn)定可能會表現(xiàn)在經(jīng)營方式和多種不同的方式取決于系統(tǒng)配置。 Traditionally, the stability problem has been one of maintaining synchronous operation. Since power systems rely on synchronous machines for generation of electrical power, a necessary condition for satisfactory system operation is that all synchronous machines remain in synchronism or, colloquially "in step". This aspect of stability is influenced by the dynamics of generator rotor an***s and power-an*** relationships, and then referred to " rotor an*** stability ". 傳統(tǒng)上，穩(wěn)定性問題一直是一個保持同步運行。由于電力系統(tǒng)的發(fā)電電力，一個令人滿意的系統(tǒng)運行的必要條件是，依靠同步電機同步電機都留在同步或通俗的“步驟”。這一方面是受穩(wěn)定的發(fā)電機轉(zhuǎn)子的動態(tài)角度和功角的關系，然后提到“轉(zhuǎn)子角穩(wěn)定”。
夏威夷： 威基基海灘、國王皇宮、恐龍灣 。 B.美國本土 應該分東部和西部來看美國的景點： 東部： 紐約（國際購物街—第五大道、洛克菲勒廣場、世貿(mào)中心遺址、帝國大廈等）－費城－華盛頓（國會大廈、白宮、林肯紀念堂等）－水牛城（尼亞加拉大瀑布） 西部： 舊金山（金門大橋等）－賭城拉斯維加斯－大峽谷 或洛杉磯（好萊塢影城等）－舊金山－－賭城拉斯維加斯－大峽谷 加州在冬天去最好，其天氣不冷不熱的。 我想推薦的是夏威夷、好萊塢-明星大道 黃石公園 尼亞加拉瀑布。 美國最熱門的25個旅游景點排名 　　　　福布斯旅游在線日前公布了他們調(diào)查得出的美國最熱門的25個旅游景點，這張清單里不僅包括類似于尼亞加拉大瀑布這樣鬼斧神工的自然風光，也包括一些令人流連忘返的游樂場所，如迪斯尼樂園或者環(huán)球影城主題公園等?？纯雌渲惺遣皇且灿心阆蛲挠斡[勝地呢？ 1、時代廣場（紐約） 年游客數(shù)：3500萬 站在時代廣場上，能看到絢麗多彩的廣告牌，川流不息的人群，更能感受到紐約的藝術氣息以及商業(yè)文化的巨大魅力。時代廣場聯(lián)盟引用了一個數(shù)據(jù)，據(jù)統(tǒng)計，在工作日，平均每十五分鐘就會有2000個人穿越曼哈頓七號大街。在新年前夕，就會有超過100萬的狂歡者匯聚到廣場上慶祝新年。 2、拉斯維加斯大道（內(nèi)華達州拉斯維加斯） 年游客數(shù)：3100萬 這條霓虹大道鋪設了拉斯維加斯瑰麗的夜生活，它不僅包含了這個罪惡之城的心臟，同時也是美國聯(lián)邦政府國家風景道計劃的一員。據(jù)統(tǒng)計，每年在這條大道上徜徉的游客人數(shù)占據(jù)了整個拉斯維加斯城市旅游人數(shù)的百分之八十。 3、國家廣場和紀念公園（華盛頓） 年游客數(shù)：2400萬 云中★漫荹〃編輯國家廣場和紀念公園占地1000多英畝，游客可以在這里發(fā)現(xiàn)很多美國歷史發(fā)展的紀念里程碑。這里還有華盛頓、林肯、杰斐遜等美國總統(tǒng)的紀念館，以及朝鮮戰(zhàn)爭和越南戰(zhàn)爭的老兵紀念館。 4、法尼爾廳市場（馬薩諸塞州波士頓） 年游客數(shù)：2000萬 1742年，富有的波士頓商人皮特·法尼爾建立了這個市場。多個世紀以來，法尼爾廳市場都是作為城市的商業(yè)中心，同時也是一個著名的演說地點，當年塞繆爾·亞當斯也曾在這里進行過演講。 5、迪斯尼世界魔幻王國（佛羅里達州奧蘭多） 年游客數(shù)：1710萬 根據(jù)全球主題公園入場人數(shù)統(tǒng)計報告，相比2006年，佛羅里達迪斯尼主題樂園游客人數(shù)增長了2。5個百分點。 6、迪斯尼公園（加利福尼亞州阿納海姆） 年游客數(shù)：1490萬 1955年，沃爾特·迪斯尼在加利福尼亞創(chuàng)建了世界上第一個迪斯尼樂園。這里有著名的海底總動員之旅，游客們可以在這里乘坐潛水艇，透過身邊圓形的視窗來賞析海底世界。 7、舊金山漁人碼頭/金門國家娛樂區(qū)（加利福尼亞州） 年游客數(shù)：1400萬 舊金山鄰近海峽，每年大約會有1580萬的游客。作為舊金山標志性景區(qū)，漁人碼頭是游客的必到之地，也是舊金山最充滿歡樂氣息的地方。金門國家娛樂區(qū)是世界最大的都市公園，包括金門大橋及海灣地區(qū)沿線廣博的區(qū)域。 　 8、尼亞加拉大瀑布（紐約州西北部） 年游客數(shù)：1200萬 瀑布位于美國和加拿大交界的尼亞加拉河中段，從19世紀中葉開始，就飽受游客的青睞。不管是站在瞭望塔上，坐在船里，還是徒步探險，游客們都能看到壯觀的大瀑布奔流而下的水勢。 9、大霧山國家公園（北卡羅來納州/田納西州） 年游客數(shù)：940萬 大霧山國家公園是美國最受歡迎的國家公園，這里有著充沛的降雨和密布的溪流，10條大瀑布和眾多小瀑布是這里的一大美景。大霧山得名于山上終年不散的煙霧，煙霧閃爍著淺藍光芒，彌漫在整個低地山巒，美不勝收。 10、海軍軍港（伊里諾斯州芝加哥） 年游客數(shù)：860萬 海軍軍港開放于1916年，它曾經(jīng)是海軍訓練場所和集會廣場，也曾是伊利諾斯大學最初的臨時校地?，F(xiàn)在，它擁有占地50英畝的商店、餐館以及博物館等公共設施。芝加哥莎士比亞劇院以及兒童博物館都在這里，游客們在夜間還能欣賞煙火表演。 11、密湖國家游樂區(qū)（亞利桑那州/內(nèi)華達州） 年游客數(shù)：760萬 密湖國家游樂區(qū)地處于拉斯維加斯東南方向30英里處，是個游泳、露營、劃船、釣魚及水上運動的勝地，也是個度假的好地方。密湖是由胡佛大壩截流科羅拉多河而形成的，它是美國最大的人工湖，同時也是美國西南部的重要水源地。 12、環(huán)球影城/冒險島（佛羅里達州奧蘭多） 年游客數(shù)：620萬 云中★漫荹〃編輯佛羅里達環(huán)球影城有兩個主題公園，一個是具有大量影視資料的環(huán)球影城，一個是可以給游客帶來驚險刺激體驗的冒險島。同時，影城推出的4D電影也吸引了不少游客。 13、奧蘭多海洋世界（佛羅里達州奧蘭多） 年游客數(shù)：600萬 奧蘭多海洋世界提供了很多大型海洋生物表演節(jié)目，海豚、海獅、海豹、海象、鯊魚和鯨魚都會在節(jié)目中亮相，其中就是殺人鯨秀場和鯨豚劇院。 14、圣安東尼奧河濱步道（德克薩斯州） 年游客數(shù)：510萬 圣安東尼奧河的河濱步道號稱是德克薩斯州第一娛樂勝地，這條綠蔭大道吸引來了來自世界各地的游客。河道兩旁聚集了餐館、商店等眾多娛樂場所。游客們游走在河濱步道上，沐浴著河面的微風，更能感受到一股濃濃的詩意。 15、圣殿廣場（猶他州鹽湖城） 年游客數(shù)：500萬 作為摩門教的中心，圣殿廣場目前已經(jīng)不僅僅是一個宗教圣地。2007年，來這里參觀的游客人數(shù)就已經(jīng)接近500萬，這也讓圣殿廣場成為了猶他州首屈一指的游覽勝地。 16、特拉華峽谷國家娛樂區(qū)（賓夕法尼亞州/新澤西州） 年游客數(shù)：480萬 特拉華峽谷國家娛樂區(qū)位于賓夕法尼亞州和新澤西州交界處，公園以河流景觀為主。 17、好萊塢環(huán)球影城（加利福尼亞州好洛杉磯） 年游客數(shù)：470萬 作為環(huán)球主題公園的旗艦品牌，好萊塢環(huán)球影城號稱是洛杉磯的娛樂之都，游客們可以親身體驗影視劇激動人心的場景。 18、紐約大都會博物館（紐約） 年游客數(shù)：450萬 大都會博物館成立于1870年，并于1880年遷址到了現(xiàn)在所在的中央公園。這是美國最大的藝術博物館，其中藝術作品就超過了200萬件。 19、威基基海灘（夏威夷） 年游客數(shù)：450萬 威基基海灘是游客心目中最典型的夏威夷海灘。這里可以沖浪、劃船、欣賞落日余暉。此外，這里商店、飯店、購物中心云集，欣賞自然美景的同時還可享受周到服務。 20、大峽谷國家公園（亞利桑拿州） 年游客數(shù)：441萬 云中★漫荹〃編輯聞名于世的大峽谷是由科羅拉多河在地質(zhì)時期長年侵蝕而形成。峽谷兩岸的不同地質(zhì)年代形成的地層斷面隨處可見，巖層清晰，是一部活生生的地質(zhì)“教科書”。1919年，大峽谷被設立為國家公園。 21、非洲布希公園（佛羅里達州坦帕灣） 年游客數(shù)：440萬 這個以非洲為主題的公園馴養(yǎng)了2700多頭動物，園內(nèi)野性十足，讓人仿佛置身非洲大陸。園區(qū)內(nèi)分為不同的主題，游客們不僅可以和野生動物親密接觸，而且還能欣賞到非洲傳統(tǒng)的民族風情。 22、科德角國家海岸（馬薩諸塞州） 年游客數(shù)：435萬 高聳的燈塔，迷人的酸果蔓池塘，還有沙丘和森林，這些無與倫比的景色讓科德角海峽熠熠生輝。在這個44600英畝的保護區(qū)里，環(huán)境優(yōu)美，細沙綿綿，游客們不僅可以感受大海的氣息，還可以徒步旅行，欣賞沿途風光。 23、圣地亞哥海洋世界（加利福尼亞州圣地亞哥） 年游客數(shù)：426萬 圣地亞哥海洋世界創(chuàng)辦于1964年，有趣的是，最初的創(chuàng)建者只是想開一間水下餐廳。目前，圣地亞哥海洋世界是世界上最大的海洋主題公園，游客們在這里不僅能欣賞到精彩的演出，而且可以親自與海洋生活進行互動游戲。 24、美國自然歷史博物館（紐約） 年游客數(shù)：400萬 美國自然歷史博物館地處于紐約曼哈頓西區(qū)，擁有45個永久展出的展廳，是世界上規(guī)模最大的自然歷史博物館。此館館藏豐富，展現(xiàn)了世界自然科學的廣博與魅力。 25、大西洋城木板路（新澤西州） 年游客數(shù)：400萬 木板路沿著海灘綿延四英里，除去唯美的自然風光，路邊還聳立著酒店、商店和各種娛樂場所。游客們信步在這條大道上，還可以順便參觀大西洋城歷史博物館和藝術中心。
The Golden Gate Bridge had the longest suspension bridge span in the world when it was completed in 1937 and has become an internationally recognized symbol of San Francisco and California. Since its completion, the span length has been surpassed by eight other bridges. It still has the second longest suspension bridge main span in the United States, after the Verrazano-Narrows Bridge in New York City. In 2007, it was ranked fifth on the List of America's Favorite Architecture by the American Institute of Architects.