工程畢業(yè)翻譯.doc

Mechanical EngineeringEngineering is an applied science. The engineer has knowledge of the mathematical and natural science gained by study, experience, and practice which is applied to develop ways to utilize economically the materials and forces of nature for the benefit of mankind. The engineer is a problem solver, using knowledge and ability to device or improves the solution to technological problems. The engineer is concerned with learning why a system or concept operates and how it might be directed toward useful beneficial products.Perhaps the broadest of the engineering disciplines, mechanical engineering is concerned with the application of science and technology in the solution of the countless problems facing our increasingly complex world.Mechanical engineers are innovators, developing devices and systems to perform useful services. They are involved in the conception, planning, design, analysis, testing, production, and utilization of facilities, systems, and machines. They are concerned with the production and use of energy, and with combustion processes, environmental control, industrial pollution, materials processing and handling, the design of transportation vehicles and propulsion systems, and the safety of products. The field of mechanical engineering may be divided into two major areas: thermosciences and design.In the thermosciences area, the mechanical engineering is concerned with thermodynamics, fluid mechanics, and heat transfer-the behavior of solids, liquids, and gases-in engineering applications. Emphasis is placed on energy conversion systems, energy analysis, the design and development of engines and propulsion systems, and the use of energy.In the design area, mechanical engineers are concerned with the development of new and improved laborsaving devices and machines. They work toward the development of devices to transmit and control mechanical power for useful purposes. Emphasis is placed on machine design, mechanisms, kinematics, and automatic controls. Mechanical engineers, for example, have had a hand in the design of a great variety of commodities. They have also been instrumental in the development of machines to produce these commodities.Metals and Their UseIt is known that metals are very important in our life. Metals have the greatest importance for industry. All machines and other engineering constructions have metal parts. Some of them consist only of metal parts.There are two large groups of metals:1. Simple metals-more or less pure chemical elements.2. Alloys-materials consisting of a simple metal combined with some other elements.About two thirds of all elements found in the earth are metals, but not all metals may be used in industry. Those metals which are used in industry are called engineering metal. The most important engineering metal is iron (Fe) which in the form of alloys with carbon (C) and other elements, finds greater use than any other metal. Metals consisting of iron combined with some other elements are known as ferrous metals; all the other metals are called nonferrous metals. The most important nonferrous metals are cooper (Cu), aluminum (Al), lead (Pb), zinc (Zn), tin (Sn), but all these metals are used much less than ferrous metals, because the ferrous metals are much cheaper.If we take all the metal produced by the worlds metallurgical industry during one year for 100 percent, we shall see that the production of ferrous metals is about 94 percent, the production of copper is about 2 percent, zinc about 1.52 percent, aluminum about 0.6 percent, etc.Engineering metals are used in industry in the form if alloys because the properties of alloys are better than the properties of pure metals. Only aluminum may be largely used in the form of a simple metal.People begin to use metals after wood and stone, but now metals are more important for industry than these two old materials. Metals have such a great importance because of their useful properties. Metals are much stronger and harder than wood and that is why some engineering constructions and machines were impossible when people did not know how to produce and how to use metals. Metal is not so brittle as stone which was the first engineering material for people. Strength, hardness, and plasticity of metals are the properties which made metals so useful for industry. It is possible to find some very plastic wood, but it will be much softer than many metals; stone may be very hard, but it is not plastic at all. Only metals have a combination of these three most useful engineering properties.But it is much more difficult to get the metals from the earth in which they are found than to find some stone or wood. That is why people began to use metals after stone and wood. The first metal which was produced by the people was copper. Iron was produced much later.Different metals are produced in different ways, but almost all the metals are found in the form of metal ore (iron ore, copper ore, etc.)The ore is a mineral consisting of a metal combined with some impurities. In order to produce a metal from some metal ore, we must separate these impurities from the metal; that is done by metallurgy.The Main Tasks of an EngineerThere are many types of industries active today. All industries require a great deal of engineer to keep new ideas and developments coming and to refine and improve manufacturing techniques.As we know, these are the main task of engineers: to explore new ways, invent new solutions to problems, and design new devices. In the research stage of a project, the engineer usually has found a new way of doing a job and is analyzing it (using mathematics and computer) to see how feasible the idea is and how well it will work. The development stage then follows. Here the idea is carried out in the laboratory. The processes vary among different project, but the basic point is the same: Turn the idea into a working reality. The development stage lasts as long as it needs to, until the working device has been constructed and tested. Then the manufacturing stage begins, during which it may be necessary to change some plan in the light of practical manufacturing condition.Following the development of a new device or product, it must be manufactured, usually in large quantities. In the last few decades a whole field of automated manufacturing techniques has been developed, requiring new engineering skills to invent and improve machines that automatically construct other machines effieiently and reliably.During production and at the end of the assembly line, a product must be carefully tested to determine if it will perform its job properly and reliably. Frequently this testing procedure must be done automatically as well. Engineers are now developing procedures and machines to carry out what can be a very complicated sequence of tests. For example, consider the enormous problem of testing a large computer to see if it will perform all its tasks correctly.In a large-scale production operation, be it many identical small items such as radios of cars or a single items such as an oil refinery, there are many problems for an engineer to deal with. In an industrial environment the engineers basic job is to plan the sequence of steps necessary for the completion of a task at minimum cost.翻譯：機械工程工程學(xué)是一種應(yīng)用科學(xué)。工程師具有從研究、經(jīng)驗和實踐中獲得的數(shù)學(xué)和自然學(xué)知識，并將其應(yīng)用到有益于人類的合理利用自然資源的可持續(xù)發(fā)展中。工程師是一個解決問題的能手，用知識和能力去設(shè)計或改善解決技術(shù)問題。工程師是以學(xué)習(xí)系統(tǒng)或概念，使其有益于產(chǎn)品。機械工程也許是工程學(xué)科中內(nèi)容最廣泛的，它涉及涉及應(yīng)用科學(xué)和技術(shù)，用于解決現(xiàn)今越來越父愛的世界中的各種問題。機械工程師是發(fā)展設(shè)備和系統(tǒng)并對其進行有效操作和保養(yǎng)的改革者。他們參與設(shè)備、系統(tǒng)和機器的概念、規(guī)劃、涉及、分析、測試、生產(chǎn)和利用。他們關(guān)注于生產(chǎn)和能源的利用、燃料燃燒過程、環(huán)境的控制、工業(yè)污染、材料的加工和處理、設(shè)計運輸車輛和推進系統(tǒng)，以及產(chǎn)品的安全性。機械工程的領(lǐng)域可以分成兩個主要領(lǐng)域 ：熱學(xué)和設(shè)計。在熱學(xué)方面，機械工程師在工程應(yīng)用中通常會接觸到熱力學(xué)、流體力學(xué)和傳熱學(xué)，即固體、液體和氣體的性能。強調(diào)的重點是能量轉(zhuǎn)換系統(tǒng)、能量分析、設(shè)計和發(fā)動機動力系統(tǒng)和能源利用的開發(fā)及發(fā)展。在設(shè)計層面，機械工程師關(guān)注于發(fā)展新的和改進節(jié)省勞動力的設(shè)備和機器。他們努力發(fā)展傳送及控制設(shè)備和機械力量的合理利用。重點在于機械設(shè)計、機制、運動學(xué)和自動控制。機械工程師，例如，他們參與各種商品的設(shè)計。他們也推動機器的發(fā)展來生產(chǎn)這些商品。金屬及其用途眾所周知，金屬在我們的生活中非常重要。金屬在工業(yè)中有有最為重要的作用。所有的及其和其他工程建筑含有金屬部分。它們中的一部分僅由金屬部分組成。金屬分為兩大類：1簡單金屬或多或少的純元素組成。2. 合金材料由一種簡單金屬結(jié)合其他一些元素組成。在地球上找到的元素中2/3是金屬，但不是所有的金屬都能應(yīng)用在工業(yè)中。在工業(yè)中使用的金屬稱為工程金屬。鐵是最重要的工程金屬，它和碳元素以及其他元素形成合金，但它比其他任何金屬的用途都大。金屬包括眾所周知的由鐵和其他元素組成的鐵質(zhì)金屬；所有其他的金屬稱為非鐵金屬。最重要的非鐵金屬有銅（Cu）、鋁（Al）、鉑（Pb）、鋅（Zn）、錫（Sn），但所有的這些金屬的使用都比鐵質(zhì)金屬少得多，因為鐵質(zhì)金屬更為便宜。如果把全世界冶金工業(yè)一年中所生產(chǎn)的金屬分為100分，我將看到鐵質(zhì)金屬的產(chǎn)量大約是94%，銅的產(chǎn)量大約是2%，鋅大約是1.52%，鋁大約是0.6%因為合金的性質(zhì)比純金屬的性質(zhì)優(yōu)越，所以工程金屬以合金的形式運用于工業(yè)中。只有鋁以簡單金屬的形式大量運用。人們開始使用金屬晚于木頭和石頭，但現(xiàn)在金屬對于工業(yè)遠比這兩種老材料重要。金屬因為他們有用的性