毕业设计英文资料翻译

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毕业设计英文作文范文

毕业设计英文作文范文

毕业设计英文作文范文Title: The Importance of the Graduation Project in Academic Development。

The graduation project holds a pivotal role in the academic journey of students. It serves as a culmination of years of learning, a platform to showcase acquired skills, and an opportunity to delve deep into a specific subject matter. In this essay, I will elaborate on the significance of the graduation project and its impact on academic development.Firstly, the graduation project fosters independent learning and critical thinking skills. Unlike regular coursework where the parameters are often well-defined, the graduation project requires students to identify a research question or a problem statement independently. This process necessitates thorough literature review, data collection, and analysis, thereby honing research and analytical abilities. Moreover, formulating hypotheses, designingexperiments, or proposing solutions demand creativethinking and problem-solving skills, which are essentialfor academic and professional success.Secondly, the graduation project encourages interdisciplinary learning and collaboration. Many projects involve aspects from various fields, prompting students to integrate knowledge acquired from different courses. This interdisciplinary approach not only enriches the project but also broadens students' perspectives, enabling them to appreciate the interconnectedness of different subjects. Furthermore, collaboration with peers, mentors, or industry professionals enhances teamwork, communication, and project management skills, which are indispensable in any academic or professional setting.Additionally, the graduation project cultivates resilience and perseverance. Research, by its nature, is fraught with challenges, setbacks, and uncertainties. Students encounter obstacles ranging from experimental failures to data inconsistencies, requiring them to adapt, troubleshoot, and persist in the face of adversity.Overcoming these hurdles instills resilience and fortitude, attributes that are invaluable not only in academia but also in life.Moreover, the graduation project offers a platform for personal and intellectual growth. It provides students with the autonomy to explore topics of their interest, delveinto uncharted territories, and push the boundaries of knowledge. This journey of self-discovery not only enhances academic curiosity but also fosters a sense of ownership and accomplishment. Furthermore, presenting findings, defending arguments, and receiving feedback during project evaluations contribute to the development of presentation, communication, and critical evaluation skills, which are essential for academic and professional success.In conclusion, the graduation project is a cornerstone of academic development, offering students a unique opportunity to apply theoretical knowledge to real-world problems, fostering independent learning, interdisciplinary collaboration, resilience, and personal growth. By engaging in this endeavor, students not only demonstrate theiracademic prowess but also equip themselves with essential skills and attributes for future endeavors. Therefore, the graduation project stands as a testament to the culmination of academic journey and the beginning of a new chapter in students' intellectual and professional pursuits.。

办公楼毕业设计英文翻译(外文翻译)

办公楼毕业设计英文翻译(外文翻译)

办公楼毕业设计英文翻译(外文翻译)原文:The future of the tall buildingAnd structure of buildingsZoning effects on the density of tall buildings and solar design may raise ethical challenge.A combined project of old and new buildings may bring back human scale to our cities. Owners and conceptual designers will be challenged in the 1980s to produce economically sound, people-oriented buildings.In 1980 the Level House, designed by Skidmore, Owings and Merril1 (SOM) received the 25-year award from the American Institut e of Architects “in recognition of architectural design of enduring significance”. This award is given once a year for a building between 25and 35 years old .Lewis Mumford described the Lever House as “the first office building in which modern materials, m odern construction, modern functions have been combined with a modern plan”. At the time, this daring concept could only be achieved by visionary men like Gordon Bunshaft , the designer , and Charles Luckman , the owner and then-president of Lever Brothers . The project also included a few “first” : (1) it was the first sealed glass tower ever built ; (2) it was the first office building designed by SOM ;and (3) it was the first office building on Park Avenue to omit retail space on the first floor. Today, after hundreds of look-alike and variations on the grid design, we have reached what may be the epitome of tall building design: the nondescript building. Except for a few recently completed buildings that seem to be people-oriented in their lower floors, most tall buildings seem to be a repletion of the dull, graph-paper-like monoliths in many of our cities. Can this be the end of the design-line for tall buildings? Probably not. There are definite signs that are most encouraging. Architects and owners have recently begun to discuss the design problem publicly. Perhaps we are at the threshold of a new era. The 1980s may bring forth some new visionaries like Bunshaft and Luckman. If so, what kinds of restrictions or challenges do they face?译文:高层建筑展望及建筑结构区域规划对高层建筑物的密度和对自然采光设计可能引起道德问题将产生影响。

java毕业设计中英文翻译

java毕业设计中英文翻译

java毕业设计中英文翻译篇一:JAVA外文文献+翻译Java and the InternetIf Java is, in fact, yet another computer programming language, you may question why it is so important and why it is being promoted as a revolutionary step in computer programming. The answer isn’t immediately obvious if you’re coming from a traditional programming perspective. Although Java is very useful for solving traditional stand-alone programming problems, it is also important because it will solve programming problems on the World Wide Web.1. Client-side programmingThe Web’s initial server-browser design provided for interactive content, but the interactivity was completely provided by the server. The server produced static pages for the client browser, which would simply interpret and display them. Basic HTML contains simple mechanisms for data gathering: text-entry boxes, check boxes, radio boxes, lists and drop-down lists, as well as a button that can only be programmed to reset the data on the form or “submit” the data on the form backto the server. This submission passes through the Common Gateway Interface (CGI) provided on all Web servers. The text within the submission tells CGI what to do with it. The most common action is to run a program located on the server in a directory that’s typically called “cgi-bin.” (If you watch the address window at the top of your browser when you push a button on a Web page, you can sometimes see “cgi-bin” within all the gobbledygook there.) These programs can be written in most languages. Perl is a common choice because it is designed for text manipulation and is interpreted, so it can be installed on any server regardless of processor or operating system. Many powerful Web sites today are built strictly on CGI, and you can in fact do nearly anything with it. However, Web sites built on CGI programs can rapidly become overly complicated to maintain, and there is also the problem of response time. The response of a CGI program depends on how much data mustbe sent, as well as the load on both the server and the Internet. (On top of this, starting a CGI program tends to be slow.) The initial designers of the Web didnot foresee how rapidly this bandwidth would be exhausted for the kinds of applications people developed. For example, any sort of dynamic graphing is nearly impossible to perform with consistency because a GIF file must be created and moved from the server to the client for each version of the graph. And you’ve no doubt had direct experience with something as simple as validating the data on an input form. You press the submit button on a page; the data is shipped back to the server; the server starts a CGI program that discovers an error, formats an HTML page informing you of the error, and then sends the page back to you; you must then back up a page and try again. Not only is this slow, it’s inelegant.The solution is client-side programming. Most machines that run Web browsers are powerful engines capable of doing vast work, and with the original static HTML approach they are sitting there, just idly waiting for the server to dish up the next page. Client-side programming means that the Web browser is harnessed to do whatever work it can, and the result for the user is a much speedier and more interactive experience atyour Web site.The problem with discussions of client-side programming is that they aren’t very different from discussions of programming in general. The parameters are almost the same, but the platform is different: a Web browser is like a limited operating system. In the end, you must still program, and this accounts for the dizzying array of problems and solutions produced by client-side programming. The rest of this section provides an overview of the issues and approaches in client-side programming.2.Plug-insOne of the most significant steps forward in client-side programming is the development of the plug-in. This is a way for a programmer to add new functionality to the browser by downloading a piece of code that plugs itself into the appropriate spot in the browser. It tells the browser “from now on you can perform this new activity.” (You need to download the plug-in only once.) Some fast and powerful behavior is added to browsers via plug-ins, but writing a plug-in is not a trivial task, and isn’t something you’d wantto do as part of the process of building a particular site. The value of the plug-in for client-side programming is that it allows an expert programmer to develop a new language and add that language to a browser without the permission of the browser manufacturer. Thus, plug-ins provide a “back door”that allows the creation of new client-side programming languages (although not all languages are implemented as plug-ins).3.Scripting languagesPlug-ins resulted in an explosion of scripting languages. With a scripting language you embed the source code for your client-side program directly into the HTML page, and the plug-in that interprets that language is automatically activated while the HTML page is being displayed. Scripting languages tend to be reasonably easy to understand and, because they are simply text that is part of an HTML page, they load very quickly as part of the single server hit required to procure that page. The trade-off is that your code is exposed for everyone to see (and steal). Generally, however, you aren’t doing amazingly sophisticatedthings with scripting languages so this is not too much of a hardship.This points out that the scripting languages used inside Web browsers are really intended to solve specific types of problems, primarily the creation of richer and more interactive graphical user interfaces (GUIs). However, a scripting language might solve 80 percent of the problems encountered in client-side programming. Your problems might very well fit completely within that 80 percent, and since scripting languages can allow easier and faster development, you should probably consider a scripting language before looking at a more involved solution such as Java or ActiveX programming.The most commonly discussed browser scripting languages are JavaScript (which has nothing to do with Java; it’s named that way just to grab some of Java’s marketing momentum), VBScript (which looks like Visual Basic), andTcl/Tk, which comes from the popular cross-platform GUI-building language. There are others out there, and no doubt more in development.JavaScript is probably the most commonly supported. It comes built into both Netscape Navigator and the Microsoft Internet Explorer (IE). In addition, there are probably more JavaScript books available than there are for the other browser languages, and some tools automatically create pages using JavaScript. However, if you’re already fluent in Visual Basic or Tcl/Tk, you’ll be more productive using those scripting languages rather than learning a new one. (You’ll have your hands full dealing with the Web issues already.)4.JavaIf a scripting language can solve 80 percent of the client-side programming problems, what about the other 20 percent—the “really hard stuff?” The most popular solution today is Java. Not only is it a powerful programming language built to be secure, cross-platform, and international, but Java is being continually extended to provide language features and libraries that elegantly handle problems that are difficult in traditional programming languages, such as multithreading, database access, network programming, and distributed computing. Java allowsclient-side programming via the applet.An applet is a mini-program that will run only under a Web browser. The applet is downloaded automatically as part of a Web page (just as, for example, a graphic is automatically downloaded). When the applet is activated it executes a program. This is part of its beauty—it provides you with a way to automatically distribute the client software from the server at the time the user needs the client software, and no sooner. The user gets the latest version of the client software without fail and without difficult reinstallation. Because of the way Java is designed, the programmer needs to create only a single program, and that program automatically works with all computers that have browsers with built-in Java interpreters. (This safely includes the vast majority of machines.) Since Java is a full-fledged programming language, you can do as much work as possible on the client before and after making requests of theserver. For example, you won’t need to send a request form across the Internet to discover that you’ve gotten a date or some other parameter wrong, and yourclient computer can quickly do the work of plotting data instead of waiting for the server to make a plot and ship a graphic image back to you. Not only do you get the immediate win of speed and responsiveness, but the general network traffic and load on servers can be reduced, preventing the entire Internet from slowing down.One advantage a Java applet has over a scripted program is that it’s in compiled form, so the source code isn’t available to the client. On the other hand, a Java applet can be decompiled without too much trouble, but hiding your code is often not an important issue. Two other factors can be important. As you will see later in this book, a compiled Java applet can comprise many modules and take multiple server “hits” (accesses) to download. (In Java 1.1 and higher this is minimized by Java archives, called JAR files, that allow all the required modules to be packaged together and compressed for a single download.) A scripted program will just be integrated into the Web page as part of its text (and will generally be smaller and reduce server hits). This could be important to the responsiveness of your Website. Another factor is the all-important learning curve. Regardless of what you’ve heard, Java is not a trivial language to learn. If you’re a Visual Basic programmer, moving to VBScript will be your fastest solution, and since it will probably solve most typical client/server problems you might be hard pressed to justify learning Java. If you’re experienced with a scripting language you will certainly benefit from looking at JavaScript or VBScript before committing to Java, since they might fit your needs handily and you’ll be more productive sooner.to run its applets withi5.ActiveXTo some degree, the competitor to Java is Microsoft’s ActiveX, although it takes a completely different approach. ActiveX was originally a Windows-only solution, although it is now being developed via an independent consortium to become cross-platform. Effectively, ActiveX says “if your program connects to篇二:JAVA思想外文翻译毕业设计文献来源:Bruce Eckel. Thinking in Java [J]. Pearson Higher Isia Education,XX-2-20.Java编程思想 (Java和因特网)既然Java不过另一种类型的程序设计语言,大家可能会奇怪它为什么值得如此重视,为什么还有这么多的人认为它是计算机程序设计的一个里程碑呢?如果您来自一个传统的程序设计背景,那么答案在刚开始的时候并不是很明显。

毕业设计中英文翻译

毕业设计中英文翻译

Bridge Waterway OpeningsIn a majority of cases the height and length of a bridge depend solely upon the amount of clear waterway opening that must be provided to accommodate the floodwaters of the stream. Actually, the problem goes beyond that of merely accommodating the floodwaters and requires prediction of the various magnitudes of floods for given time intervals. It would be impossible to state that some given magnitude is the maximum that will ever occur, and it is therefore impossible to design for the maximum, since it cannot be ascertained. It seems more logical to design for a predicted flood of some selected interval ---a flood magnitude that could reasonably be expected to occur once within a given number of years. For example, a bridge may be designed for a 50-year flood interval; that is, for a flood which is expected (according to the laws of probability) to occur on the average of one time in 50 years. Once this design flood frequency, or interval of expected occurrence, has been decided, the analysis to determine a magnitude is made. Whenever possible, this analysis is based upon gauged stream records. In areas and for streams where flood frequency and magnitude records are not available, an analysis can still be made. With data from gauged streams in the vicinity, regional flood frequencies can be worked out; with a correlation between the computed discharge for the ungauged stream and the regional flood frequency, a flood frequency curve can be computed for the stream in question. Highway CulvertsAny closed conduit used to conduct surface runoff from one side of a roadway to the other is referred to as a culvert. Culverts vary in size from large multiple installations used in lieu of a bridge to small circular or elliptical pipe, and their design varies in significance. Accepted practice treats conduits under the roadway as culverts. Although the unit cost of culverts is much less than that of bridges, they are far more numerous, normally averaging about eight to the mile, and represent a greater cost in highway. Statistics show that about 15 cents of the highway construction dollar goes to culverts, as compared with 10 cents for bridge. Culvert design then is equally as important as that of bridges or other phases of highway and should be treated accordingly.Municipal Storm DrainageIn urban and suburban areas, runoff waters are handled through a system of drainage structures referred to as storm sewers and their appurtenances. The drainage problem is increased in these areas primarily for two reasons: the impervious nature of the area creates a very high runoff; and there is little room for natural water courses. It is often necessary to collect the entire storm water into a system of pipes and transmit it over considerable distances before it can be loosed again as surface runoff. This collection and transmission further increase the problem, since all of the water must be collected with virtually no ponding, thus eliminating any natural storage; and though increased velocity the peak runoffs are reached more quickly. Also, the shorter times of peaks cause the system to be more sensitive to short-duration, high-intensity rainfall. Storm sewers, like culverts and bridges, are designed for storms of various intensity –return-period relationship, depending upon the economy and amount of ponding that can be tolerated.Airport DrainageThe problem of providing proper drainage facilities for airports is similar in many ways to that of highways and streets. However, because of the large and relatively flat surface involved the varying soil conditions, the absence of natural water courses and possible side ditches, and the greater concentration of discharge at the terminus of the construction area, some phases of the problem are more complex. For the average airport the overall area to be drained is relatively large and an extensive drainage system is required. The magnitude of such a system makes it even more imperative that sound engineeringprinciples based on all of the best available data be used to ensure the most economical design. Overdesign of facilities results in excessive money investment with no return, and underdesign can result in conditions hazardous to the air traffic using the airport.In other to ensure surfaces that are smooth, firm, stable, and reasonably free from flooding, it is necessary to provide a system which will do several things. It must collect and remove the surface water from the airport surface; intercept and remove surface water flowing toward the airport from adjacent areas; collect and remove any excessive subsurface water beneath the surface of the airport facilities and in many cases lower the ground-water table; and provide protection against erosion of the sloping areas. Ditches and Cut-slope DrainageA highway cross section normally includes one and often two ditches paralleling the roadway. Generally referred to as side ditches these serve to intercept the drainage from slopes and to conduct it to where it can be carried under the roadway or away from the highway section, depending upon the natural drainage. To a limited extent they also serve to conduct subsurface drainage from beneath the roadway to points where it can be carried away from the highway section.A second type of ditch, generally referred to as a crown ditch, is often used for the erosion protection of cut slopes. This ditch along the top of the cut slope serves to intercept surface runoff from the slopes above and conduct it to natural water courses on milder slopes, thus preventing the erosion that would be caused by permitting the runoff to spill down the cut faces.12 Construction techniquesThe decision of how a bridge should be built depends mainly on local conditions. These include cost of materials, available equipment, allowable construction time and environmental restriction. Since all these vary with location and time, the best construction technique for a given structure may also vary. Incremental launching or Push-out MethodIn this form of construction the deck is pushed across the span with hydraulic rams or winches. Decks of prestressed post-tensioned precast segments, steel or girders have been erected. Usually spans are limited to 50~60 m to avoid excessive deflection and cantilever stresses , although greater distances have been bridged by installing temporary support towers . Typically the method is most appropriate for long, multi-span bridges in the range 300 ~ 600 m ,but ,much shorter and longer bridges have been constructed . Unfortunately, this very economical mode of construction can only be applied when both the horizontal and vertical alignments of the deck are perfectly straight, or alternatively of constant radius. Where pushing involves a small downward grade (4% ~ 5%) then a braking system should be installed to prevent the deck slipping away uncontrolled and heavy bracing is then needed at the restraining piers.Bridge launching demands very careful surveying and setting out with continuous and precise checks made of deck deflections. A light aluminum or steel-launching nose forms the head of the deck to provide guidance over the pier. Special teflon or chrome-nickel steel plate bearings are used to reduce sliding friction to about 5% of the weight, thus slender piers would normally be supplemented with braced columns to avoid cracking and other damage. These columns would generally also support the temporary friction bearings and help steer the nose.In the case of precast construction, ideally segments should be cast on beds near the abutments and transferred by rail to the post-tensioning bed, the actual transport distance obviously being kept to the minimum. Usually a segment is cast against the face of the previously concerted unit to ensure a good fit when finally glued in place with an epoxy resin. If this procedure is not adopted , gaps of approximately 500mm shold be left between segments with the reinforcements running through andstressed together to form a complete unit , but when access or space on the embankment is at a premium it may be necessary to launch the deck intermittently to allow sections to be added progressively .The correponding prestressing arrangements , both for the temporary and permanent conditions would be more complicated and careful calculations needed at all positions .The pricipal advantage of the bridge-launching technique is the saving in falsework, especially for high decks. Segments can also be fabricated or precast in a protected environment using highly productive equipment. For concrete segment, typically two segment are laid each week (usually 10 ~ 30 m in length and perhaps 300 to 400 tonnes in weight) and after posttensioning incrementally launched at about 20 m per day depending upon the winching/jacking equipment.Balanced Cantiulever ConstructionDevelopment in box section and prestressed concrete led to short segment being assembled or cast in place on falsework to form a beam of full roadway width. Subsequently the method was refined virtually to eliminate the falsework by using a previously constructed section of the beam to provide the fixing for a subsequently cantilevered section. The principle is demonsrated step-by-step in the example shown in Fig.1.In the simple case illustrated, the bridge consists of three spans in the ratio 1:1:2. First the abutments and piers are constructed independently from the bridge superstructure. The segment immediately above each pier is then either cast in situ or placed as a precast unit .The deck is subsequently formed by adding sections symmetrically either side.Ideally sections either side should be placed simultaneously but this is usually impracticable and some inbalance will result from the extra segment weight, wind forces, construction plant and material. When the cantilever has reached both the abutment and centre span,work can begin from the other pier , and the remainder of the deck completed in a similar manner . Finally the two individual cantilevers are linked at the centre by a key segment to form a single span. The key is normally cast in situ.The procedure initially requires the first sections above the column and perhaps one or two each side to be erected conventionally either in situ concrete or precast and temporarily supported while steel tendons are threaded and post-tensioned . Subsequent pairs of section are added and held in place by post-tensioning followed by grouting of the ducts. During this phase only the cantilever tendons in the upper flange and webs are tensioned. Continuity tendons are stressed after the key section has been cast in place. The final gap left between the two half spans should be wide enough to enable the jacking equipment to be inserted. When the individual cantilevers are completed and the key section inserted the continuity tendons are anchored symmetrically about the centre of the span and serve to resist superimposed loads, live loads, redistribution of dead loads and cantilever prestressing forces.The earlier bridges were designed on the free cantilever principle with an expansion joint incorporated at the center .Unfortunately,settlements , deformations , concrete creep and prestress relaxation tended to produce deflection in each half span , disfiguring the general appearance of the bridge and causing discomfort to drivers .These effects coupled with the difficulties in designing a suitable joint led designers to choose a continuous connection, resulting in a more uniform distribution of the loads and reduced deflection. The natural movements were provided for at the bridge abutments using sliding bearings or in the case of long multi-span bridges, joints at about 500 m centres.Special Requirements in Advanced Construction TechniquesThere are three important areas that the engineering and construction team has to consider:(1) Stress analysis during construction: Because the loadings and support conditions of the bridge are different from the finished bridge, stresses in each construction stage must be calculated to ensurethe safety of the structure .For this purpose, realistic construction loads must be used and site personnel must be informed on all the loading limitations. Wind and temperature are usually significant for construction stage.(2) Camber: In order to obtain a bridge with the right elevation, the required camber of the bridge at each construction stage must be calculated. It is required that due consideration be given to creep and shrinkage of the concrete. This kind of the concrete. This kind of calculation, although cumbersome, has been simplified by the use of the compiters.(3) Quality control: This is important for any method construction, but it is more so for the complicated construction techniques. Curing of concrete, post-tensioning, joint preparation, etc. are detrimental to a successful structure. The site personnel must be made aware of the minimum concrete strengths required for post-tensioning, form removal, falsework removal, launching and other steps of operations.Generally speaking, these advanced construction techniques require more engineering work than the conventional falsework type construction, but the saving could be significant.大桥涵洞在大多数情况中桥梁的高度和跨度完全取决于河流的流量,桥梁的高度和跨度必须能够容纳最大洪水量.事实上,这不仅仅是洪水最大流量的问题,还需要在不同时间间隔预测不同程度的水灾。

毕业设计(论文)外文资料翻译(学生用)

毕业设计(论文)外文资料翻译(学生用)

毕业设计外文资料翻译学院:信息科学与工程学院专业:软件工程姓名: XXXXX学号: XXXXXXXXX外文出处: Think In Java (用外文写)附件: 1.外文资料翻译译文;2.外文原文。

附件1:外文资料翻译译文网络编程历史上的网络编程都倾向于困难、复杂,而且极易出错。

程序员必须掌握与网络有关的大量细节,有时甚至要对硬件有深刻的认识。

一般地,我们需要理解连网协议中不同的“层”(Layer)。

而且对于每个连网库,一般都包含了数量众多的函数,分别涉及信息块的连接、打包和拆包;这些块的来回运输;以及握手等等。

这是一项令人痛苦的工作。

但是,连网本身的概念并不是很难。

我们想获得位于其他地方某台机器上的信息,并把它们移到这儿;或者相反。

这与读写文件非常相似,只是文件存在于远程机器上,而且远程机器有权决定如何处理我们请求或者发送的数据。

Java最出色的一个地方就是它的“无痛苦连网”概念。

有关连网的基层细节已被尽可能地提取出去,并隐藏在JVM以及Java的本机安装系统里进行控制。

我们使用的编程模型是一个文件的模型;事实上,网络连接(一个“套接字”)已被封装到系统对象里,所以可象对其他数据流那样采用同样的方法调用。

除此以外,在我们处理另一个连网问题——同时控制多个网络连接——的时候,Java内建的多线程机制也是十分方便的。

本章将用一系列易懂的例子解释Java的连网支持。

15.1 机器的标识当然,为了分辨来自别处的一台机器,以及为了保证自己连接的是希望的那台机器,必须有一种机制能独一无二地标识出网络内的每台机器。

早期网络只解决了如何在本地网络环境中为机器提供唯一的名字。

但Java面向的是整个因特网,这要求用一种机制对来自世界各地的机器进行标识。

为达到这个目的,我们采用了IP(互联网地址)的概念。

IP以两种形式存在着:(1) 大家最熟悉的DNS(域名服务)形式。

我自己的域名是。

所以假定我在自己的域内有一台名为Opus的计算机,它的域名就可以是。

软件工程专业毕业设计外文文献翻译

软件工程专业毕业设计外文文献翻译

软件工程专业毕业设计外文文献翻译1000字本文将就软件工程专业毕业设计的外文文献进行翻译,能够为相关考生提供一定的参考。

外文文献1: Software Engineering Practices in Industry: A Case StudyAbstractThis paper reports a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The study investigated the company’s software development process, practices, and techniques that lead to the production of quality software. The software engineering practices were identified through a survey questionnaire and a series of interviews with the company’s software development managers, software engineers, and testers. The research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company follows a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The findings of this study provide a valuable insight into the software engineering practices used in industry and can be used to guide software engineering education and practice in academia.IntroductionSoftware engineering is the discipline of designing, developing, testing, and maintaining software products. There are a number of software engineering practices that are used in industry to ensure that software products are of high quality, reliable, and maintainable. These practices include software development processes, software configuration management, software testing, requirements engineering, and project management. Software engineeringpractices have evolved over the years as a result of the growth of the software industry and the increasing demands for high-quality software products. The software industry has developed a number of software development models, such as the Capability Maturity Model Integration (CMMI), which provides a framework for software development organizations to improve their software development processes and practices.This paper reports a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The objective of the study was to identify the software engineering practices used by the company and to investigate how these practices contribute to the production of quality software.Research MethodologyThe case study was conducted with a large US software development company that produces software for aerospace and medical applications. The study was conducted over a period of six months, during which a survey questionnaire was administered to the company’s software development managers, software engineers, and testers. In addition, a series of interviews were conducted with the company’s software development managers, software engineers, and testers to gain a deeper understanding of the software engineering practices used by the company. The survey questionnaire and the interview questions were designed to investigate the software engineering practices used by the company in relation to software development processes, software configuration management, software testing, requirements engineering, and project management.FindingsThe research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company’s software development process consists of five levels of maturity, starting with an ad hoc process (Level 1) and progressing to a fully defined and optimized process (Level 5). The company has achieved Level 3 maturity in its software development process. The company follows a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The software engineering practices used by the company include:Software Configuration Management (SCM): The company uses SCM tools to manage software code, documentation, and other artifacts. The company follows a branching and merging strategy to manage changes to the software code.Software Testing: The company has adopted a formal testing approach that includes unit testing, integration testing, system testing, and acceptance testing. The testing process is automated where possible, and the company uses a range of testing tools.Requirements Engineering: The company has a well-defined requirements engineering process, which includes requirements capture, analysis, specification, and validation. The company uses a range of tools, including use case modeling, to capture and analyze requirements.Project Management: The company has a well-defined project management process that includes project planning, scheduling, monitoring, and control. The company uses a range of tools to support project management, including project management software, which is used to track project progress.ConclusionThis paper has reported a case study of software engineering practices in industry. The study was conducted with a large US software development company that produces software for aerospace and medical applications. The study investigated the company’s software development process,practices, and techniques that lead to the production of quality software. The research found that the company has a well-defined software development process, which is based on the Capability Maturity Model Integration (CMMI). The company uses a set of software engineering practices that ensure quality, reliability, and maintainability of the software products. The findings of this study provide a valuable insight into the software engineering practices used in industry and can be used to guide software engineering education and practice in academia.外文文献2: Agile Software Development: Principles, Patterns, and PracticesAbstractAgile software development is a set of values, principles, and practices for developing software. The Agile Manifesto represents the values and principles of the agile approach. The manifesto emphasizes the importance of individuals and interactions, working software, customer collaboration, and responding to change. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases. This paper presents an overview of agile software development, including its principles, patterns, and practices. The paper also discusses the benefits and challenges of agile software development.IntroductionAgile software development is a set of values, principles, and practices for developing software. Agile software development is based on the Agile Manifesto, which represents the values and principles of the agile approach. The manifesto emphasizes the importance of individuals and interactions, working software, customer collaboration, and responding to change. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases.Agile Software Development PrinciplesAgile software development is based on a set of principles. These principles are:Customer satisfaction through early and continuous delivery of useful software.Welcome changing requirements, even late in development. Agile processes harness change for the customer's competitive advantage.Deliver working software frequently, with a preference for the shorter timescale.Collaboration between the business stakeholders and developers throughout the project.Build projects around motivated individuals. Give them the environment and support they need, and trust them to get the job done.The most efficient and effective method of conveying information to and within a development team is face-to-face conversation.Working software is the primary measure of progress.Agile processes promote sustainable development. The sponsors, developers, and users should be able to maintain a constant pace indefinitely.Continuous attention to technical excellence and good design enhances agility.Simplicity – the art of maximizing the amount of work not done – is essential.The best architectures, requirements, and designs emerge from self-organizing teams.Agile Software Development PatternsAgile software development patterns are reusable solutions to common software development problems. The following are some typical agile software development patterns:The Single Responsibility Principle (SRP)The Open/Closed Principle (OCP)The Liskov Substitution Principle (LSP)The Dependency Inversion Principle (DIP)The Interface Segregation Principle (ISP)The Model-View-Controller (MVC) PatternThe Observer PatternThe Strategy PatternThe Factory Method PatternAgile Software Development PracticesAgile software development practices are a set ofactivities and techniques used in agile software development. The following are some typical agile software development practices:Iterative DevelopmentTest-Driven Development (TDD)Continuous IntegrationRefactoringPair ProgrammingAgile Software Development Benefits and ChallengesAgile software development has many benefits, including:Increased customer satisfactionIncreased qualityIncreased productivityIncreased flexibilityIncreased visibilityReduced riskAgile software development also has some challenges, including:Requires discipline and trainingRequires an experienced teamRequires good communicationRequires a supportive management cultureConclusionAgile software development is a set of values, principles, and practices for developing software. Agile software development is based on the Agile Manifesto, which represents the values and principles of the agile approach. Agile software development practices include iterative development, test-driven development, continuous integration, and frequent releases. Agile software development has many benefits, including increased customer satisfaction, increased quality, increased productivity, increased flexibility, increased visibility, and reduced risk. Agile software development also has some challenges, including the requirement for discipline and training, the requirement for an experienced team, the requirement for good communication, and the requirement for a supportive management culture.。

毕业设计论文化学系毕业论文外文文献翻译中英文

毕业设计论文化学系毕业论文外文文献翻译中英文

毕业设计论文化学系毕业论文外文文献翻译中英文英文文献及翻译A chemical compound that is contained in the hands of the problemsfor exampleCatalytic asymmetric carbon-carbon bond formation is one of the most active research areas in organic synthesis In this field the application of chiral ligands in enantioselective addition of diethylzinc to aldehydes has attracted much attention lots of ligands such as chiral amino alcohols amino thiols piperazines quaternary ammonium salts 12-diols oxazaborolidines and transition metal complex with chiral ligands have been empolyed in the asymmetric addition of diethylzinc to aldehydes In this dissertation we report some new chiral ligands and their application in enantioselective addition of diethylzinc to aldehydes1 Synthesis and application of chiral ligands containing sulfur atomSeveral a-hydroxy acids were prepared using the literature method with modifications from the corresponding amino acids valine leucine and phenylalanine Improved yields were obtained by slowly simultaneous addition of three fold excess of sodium nitrite and 1 tnolL H2SO4 In the preparation of a-hydroxy acid methyl esters from a-hydroxy acids following the procedure described by Vigneron a low yield 45 was obtained It was found that much better results yield 82 couldbe obtained by esterifying a-hydroxy acids with methanol-thionyl chlorideThe first attempt to convert S -2-hydroxy-3-methylbutanoic acid methyl ester to the corresponding R-11-diphenyl-2-mercapto-3-methyl-l-butanol is as the following S-2-Hydroxy-3-methylbutanoic acid methyl ester was treated with excess of phenylmagnesium bromide to give S -11-diphenyl-3-methyl-12-butanediol which was then mesylated to obtain S -11-diphenyl-3-methyl-2-methanesulfonyloxy -l-butanol Unfortunately conversion of S-11-diphenyl-3-methyl-2- methanesulfonyloxy -l-butanol to the corresponding thioester by reacting with potassium thioacetate under Sn2 reaction conditions can be achieved neither in DMF at 20-60 nor in refluxing toluene in the presence of 18-crown-6 as catalyst When S -1ll-diphenyl-3-methyl-2- methane sulfonyloxy -l-butanol was refluxed with thioacetic acid in pyridine an optical active epoxide R-22-diphenyl -3-isopropyloxirane was obtained Then we tried to convert S -11-diphenyl-3-methyl-l2-butanediol to the thioester by reacting with PPh3 DEAD and thioacetic acid the Mitsunobu reaction but we failed either probably due to the steric hindrance around the reaction centerThe actually successful synthesis is as described below a-hydroxy acid methyl esters was mesylated and treated with KSCOCH3 in DMF to give thioester this was than treated with phenyl magnesium bromide to gave the target compound B-mercaptoalcohols The enantiomeric excesses ofp-mercaptoalcohols can be determined by 1H NMR as their S -mandeloyl derivatives S -2-amino-3-phenylpropane-l-thiol hydrochloride was synthesized from L-Phenylalanine L-Phenylalanine was reduced to the amino alcohol S -2-amino-3-phenylpropanol Protection of the amino group using tert-butyl pyrocarbonate gave S -2-tert-butoxycarbonylamino-3-phenylpropane-l-ol which was then O-mesylated to give S -2-tert-butoxycarbonylamino-3-phenylpropyl methanesulfonate The mesylate was treated with potassium thioacetate in DMF to give l-acetylthio-2-tert-butoxycarbonylamino-3-phenylpropane The acetyl group was then removed by treating with ammonia in alcohol to gave S -2-tert-butoxycarbonylamino-3-phenyl-propane-l-thiol which was then deprotected with hydrochloric acid to give the desired S-2-amino-3-phenylpropane-1-thiol hydrochlorideThe enantioselective addition of diethylzinc to aldehydes promoted by these sulfur containing chiral ligands produce secondary alcohols in 65-79 Synthesis and application of chiral aminophenolsThree substituted prolinols were prepared from the naturally-occurring L-proline using reported method with modifications And the chiral aminophenols were obtained by heating these prolinols with excess of salicylaldehyde in benzene at refluxThe results of enantioselective adBelow us an illustration forexampleN-Heterocyclic carbenes and L-Azetidine-2-carboxylicacidN-Heterocyclic carbenesN-Heterocyclic carbenes have becomeuniversal ligands in organometallic and inorganic coordination chemistry They not only bind to any transition metal with low or high oxidation states but also to main group elements such as beryllium sulfur and iodine Because of their specific coordination chemistry N-heterocyclic carbenes both stabilize and activate metal centers in quite different key catalytic steps of organic syntheses for example C-H activation C-C C-H C-O and C-N bond formation There is now ample evidence that in the new generation of organometallic catalysts the established ligand class of organophosphanes will be supplemented and in part replaced byN-heterocyclic carbenes Over the past few years this chemistry has become the field of vivid scientific competition and yielded previously unexpected successes in key areas of homogeneous catalysis From the work in numerous academic laboratories and in industry a revolutionary turningpoint in oraganometallic catalysis is emergingIn this thesis Palladium Ⅱ acetate and NN"-bis- 26-diisopropylphenyl dihydro- imidazolium chloride 1 2 mol were used to catalyze the carbonylative coupling of aryl diazonium tetrafluoroborate salts and aryl boronic acids to form aryl ketones Optimal conditions include carbon monoxide 1 atm in 14-dioxane at 100℃ for 5 h Yields for unsymmetrical aryl ketones ranged from 76 to 90 for isolated materials with only minor amounts of biaryl coupling product observed 2-12 THF as solvent gave mixtures of products 14-Dioxane proved to be the superior solvent giving higher yieldsof ketone product together with less biphenyl formation At room temperature and at 0℃ with 1 atm CO biphenyl became the major product Electron-rich diazonium ion substrates gave a reduced yield with increased production of biaryl product Electron-deficient diazonium ions were even better forming ketones in higher yields with less biaryl by-product formed 2-Naphthyldiazonium salt also proved to be an effective substrate givingketones in the excellent range Base on above palladium NHC catalysts aryl diazonium tetrafluoroborates have been coupled with arylboron compounds carbon monoxide and ammonia to give aryl amides in high yields A saturated yV-heterocyclic carbene NHC ligand H2lPr 1 was used with palladium II acetate to give the active catalyst The optimal conditions with 2mol palladium-NHC catalyst were applied with various organoboron compounds and three aryl diazonium tetrafluoroborates to give numerous aryl amides in high yield using pressurized CO in a THF solution saturated with ammonia Factors that affect the distribution of the reaction products have been identified and a mechanism is proposed for this novel four-component coupling reactionNHC-metal complexes are commonly formed from an imidazolium salt using strong base Deprotonation occurs at C2 to give a stable carbene that adds to form a a-complex with the metal Crystals were obtained from the reaction of imidazolium chloride with sodium t- butoxide Nal and palladium II acetate giving a dimeric palladium II iodide NHC complex The structure adopts a flat 4-memberedring u2 -bridged arrangement as seen in a related dehydro NHC complex formed with base We were pleased to find that chloride treated with palladium II acetate without adding base or halide in THF also produced suitable crystals for X-ray anaysis In contrast to the diiodide the palladium-carbenes are now twisted out of plane adopting a non-planar 4-ring core The borylation of aryldiazonium tetrafluoroborates with bis pinacolatoborane was optimized using various NHC ligand complexes formed in situ without adding base NN"-Bis 26-diisopropylphenyl-45-dihydroimidazolium 1 used with palladium acetate in THF proved optimal giving borylated product in 79 isolated yield without forming of bi-aryl side product With K2CO3 and ligand 1 a significant amount of biaryl product 24 was again seen The characterization of the palladium chloride complex by X-ray chrastallography deL-Azetidine-2-carboxylic acidL-Azetidine-2-carboxylic acid also named S -Azetidine-2-carboxylic acid commonly named L-Aze was first isolated in 1955 by Fowden from Convallaria majalis and was the first known example of naturally occurring azetidine As a constrained amino acid S -Azetidine-2-carboxylic acid has found many applications in the modification of peptides conformations and in the area of asymmetric synthesis which include its use in the asymmetric reduction of ketones Michael additions cyclopropanations and Diels-Alder reactions In this dissertation five ways for synthesize S-Azetidine-2-carboxylic acid were studied After comparing all methods theway using L-Aspartic acid as original material for synthesize S-Azetidine-2-carboxylic acid was considered more feasible All mechanisms of the way"s reaction have also been studied At last the application and foreground of S -Azetidine-2-carboxylic acid were viewed The structures of the synthetic products were characterized by ThermalGravity-Differential Thermal Analysis TG-DTA Infrared Spectroscopy IR Mass Spectra MS and 1H Nuclear Magnetic Resonance 1H-NMR Results showed that the structures and performances of the products conformed to the anticipation the yield of each reaction was more than 70 These can conclude that the way using L-Aspartie acid as original material for synthesize S -Azetidine-2-carboxylic acid is practical and effective杂环化合物生成中包含手性等问题如催化形成不对称碳碳键在有机合成中是一个非常活跃的领域在这个领域中利用手性配体诱导的二乙基锌和醛的不对称加成引起化学家的广泛关注许多手性配体如手性氨基醇手性氨基硫醇手性哌嗪手性四季铵盐手性二醇手性恶唑硼烷和过渡金属与手性配体的配合物等被应用于二乙基锌对醛的不对称加成中在本论文中我们报道了一些新型的手性配体的合成及它们应用于二乙基锌对醛的不对称加成的结果1含硫手性配体的合成和应用首先从氨基酸缬氨酸亮氨酸苯丙氨酸出发按照文献合成α-羟基酸并发现用三倍量的亚硝酸钠和稀硫酸同时滴加进行反应能适当提高反应的产率而根据Vigneron等人报道的的方法用浓盐酸催化从α-羟基酸合成α-羟基酸甲酯时只能获得较低的产率改用甲醇-二氯亚砜的酯化方法时能提高该步骤的产率从 S -3-甲基-2-羟基丁酸甲酯合成 R -3-甲基-11-二苯基-2-巯基-1-丁醇经过了以下的尝试 S -3-甲基-2-羟基丁酸甲酯和过量的格氏试剂反应得到 S -3-甲基-11-二苯基-12-丁二醇进行甲磺酰化时位阻较小的羟基被磺酰化生成 S -3-甲基-11-二苯基-2- 甲磺酰氧基 -1-丁醇但无论将 S -3-甲基-11-二苯基-2- 甲磺酰氧基 -1-丁醇和硫代乙酸钾在DMF中反应 20~60℃还是在甲苯中加入18-冠-6作为催化剂加热回流都不能得到目标产物当其与硫代乙酸在吡啶中回流时得到的不是目标产物而是手性环氧化合物 R -3-异丙基-22-二苯基氧杂环丙烷从化合物 S -3-甲基-11-二苯基-12-丁二醇通过Mitsunobu反应合成硫代酯也未获得成功这可能是由于在反应中心处的位阻较大造成的几奥斯塑手村犯体的合成裁其在不对称奋成中肠左用摘要成功合成疏基醇的合成路是将a-轻基酸甲酷甲磺酞化得到相应的磺酞化产物并进行与硫代乙酸钾的亲核取代反应得到硫酷进行格氏反应后得到目标分子p一疏基醇用p一疏基醇与 R 义一一甲氧基苯乙酞氯生成的非对映体经H侧NM吸测试其甲氧基峰面积的积分求得其ee值 3一苯基一氨基丙硫醇盐酸盐从苯丙氨酸合成斗3一苯基一氨基丙醇由L一苯丙氨酸还原制备氨基保护后得到习一3一苯基一2一叔丁氧拨基氨基一1一丙醇甲磺酞化后得到习一3一苯基一2一叔丁氧拨基氨基一1一丙醇甲磺酸酷用硫代乙酸钾取代后得匀一3-苯基一2一叔丁氧拨基氨基一1一丙硫醇乙酸酷氨解得习一3一苯基一2一叔丁氧拨基氨基一1一丙硫醇用盐酸脱保护后得到目标产物扔3一苯基屯一氨基丙硫醇盐酸盐手性含硫配体诱导下的二乙基锌与醛的加成所得产物的产率为65一79值为O井92手性氨基酚的合成和应用首先从天然的L一脯氨酸从文献报道的步骤合成了三种脯氨醇这些手性氨基醇与水杨醛在苯中回流反应得到手性氨基酚手性氨基酚配体诱导下的二乙基锌与醛的加成所得产物的产率为45一98值为0一90手性二茂铁甲基氨基醇的合成和应用首先从天然氨基酸绿氨酸亮氨酸苯丙氨酸和脯氨酸合成相应的氨基醇这些氨基醇与二茂铁甲醛反应生成的NO一缩醛经硼氢化钠还原得到手性二茂铁甲基氨基醇手性二茂铁甲基氨基醇配体诱导下的二乙基锌与醛的加成所得产物的产率为66一97下面我们举例说明一下例如含氮杂环卡宾和L-氮杂环丁烷-2-羧酸含氮杂环卡宾含氮杂环卡宾已广泛应用于有机金属化学和无机配合物化学领域中它们不仅可以很好地与任何氧化态的过渡金属络合还可以与主族元素铍硫等形成配合物由于含氮杂环卡宾不但使金属中心稳定而且还可以活化此金属中心使其在有机合成中例如C-H键的活化C-CC-HC-O和C-N键形成反应中有着十分重要的催化效能现有的证据充分表明在新一代有机金属催化剂中含氮杂环卡宾不但对有机膦类配体有良好的互补作用而且在有些方面取代有机膦配体成为主角近年来含氮杂环卡宾及其配合物已成为非常活跃的研究领域在均相催化这一重要学科中取得了难以想象的成功所以含氮杂环卡宾在均相有机金属催化领域的研究工作很有必要深入地进行下去本文研究了乙酸钯和NN双 26-二异丙基苯基 -45-二氢咪唑氯化物1作为催化剂催化芳基四氟硼酸重氮盐与芳基硼酸的羰基化反应合成了一系列二芳基酮并对反应条件进行了优化使反应在常温常压下进行一个大气压的一氧化碳14-二氧杂环己烷作溶剂100℃反应5h 不同芳基酮的收率达7690仅有微量的联芳烃付产物 212 反应选择性良好当采用四氢呋喃或甲苯作溶剂时得到含较多副产物的混合物由此可以证明14-二氧杂环己烷是该反应最适宜的溶剂在室温或0℃与一个大气压的一氧化碳反应联芳烃变成主产物含供电子取代基的芳基重氮盐常常给出较低收率的二芳基酮而含吸电子取代基的芳基重氮盐却给出更高收率的二芳基酮及较少量的联芳烃付产物实验证明2-萘基重氮盐具有很好的反应活性和选择性总是得到优异的反应结果在此基础上由不同的芳基四氟硼酸重氮盐与芳基硼酸一氧化碳和氨气协同作用以上述含氮杂环卡宾作配体与乙酸钯生成的高活性含氮杂环卡宾钯催化剂催化较高收率地得到了芳基酰胺优化的反应条件是使用2mol的钯-H_2IPr 1五个大气压的一氧化碳以氨气饱和的四氢呋喃作溶剂由不同的有机硼化合物与三种芳基重氮盐的四组份偶联反应同时不仅对生成的多种产物进行了定 L-氮杂环丁烷-2-羧酸L-氮杂环丁烷-2-羧酸又称 S -氮杂环丁烷-2-羧酸简称为L-Aze1955年由Fowden从植物铃兰 Convallaria majalis 中分离得到成为第一个被证实的植物中天然存在的氮杂环丁烷结构作为一种非典型的氨基酸已经发现 S -氮杂环丁烷-2-羧酸可广泛用于对多肽结构的修饰以及诸如不对称的羰基还原Michael 加成环丙烷化和Diels-Alder反应等不对称合成中的多个领域本文通过对 S -氮杂环丁烷-2-羧酸合成路线的研究综述了五种可行的合成路线及方法通过比较选用以L-天冬氨酸为初始原料合成 S -氮杂环丁烷-2-羧酸的路线即通过酯化反应活泼氢保护格氏反应内酰胺化反应还原反应氨基保护氧化反应脱保护等反应来合成 S -氮杂环丁烷-2-羧酸分析了每步反应的机理并对 S -氮杂环丁烷-2-羧酸的应用及前景给予展望通过热分析红外质谱核磁等分析手段对合成的化合物的结构进行表征结果表明所得的产物符合目标产物所合成的化合物的结构性能指标与设计的目标要求一致每步反应的收率都在70%以上可以判定以L-天冬氨酸为初始原料合成 S -氮杂环丁烷的路线方案切实可行。

毕业设计(论文)外文翻译

毕业设计(论文)外文翻译

华南理工大学广州学院本科生毕业设计(论文)翻译外文原文名Agency Cost under the Restriction of Free Cash Flow中文译名自由现金流量的限制下的代理成本学院管理学院专业班级会计学3班学生姓名陈洁玉学生学号200930191100指导教师余勍讲师填写日期2015年5月11日外文原文版出处:译文成绩:指导教师(导师组长)签名:译文:自由现金流量的限制下的代理成本摘要代理成本理论是资本结构理论的一个重要分支。

自由现金流代理成本有显着的影响。

在这两个领域相结合的研究,将有助于建立和扩大理论体系。

代理成本理论基础上,本研究首先分类自由现金流以及统计方法的特点。

此外,投资自由现金流代理成本的存在证明了模型。

自由现金流代理成本理论引入限制,分析表明,它会改变代理成本,进而将影响代理成本和资本结构之间的关系,最后,都会影响到最优资本结构点,以保持平衡。

具体地说,自由现金流增加,相应地,债务比例会降低。

关键词:资本结构,现金流,代理成本,非金钱利益1、介绍代理成本理论,金融契约理论,信号模型和新的啄食顺序理论,新的资本结构理论的主要分支。

财务con-道的理论侧重于限制股东的合同行为,解决股东和债权人之间的冲突。

信令模式和新的啄食顺序理论中心解决投资者和管理者之间的冲突。

这两种类型的冲突是在商业组织中的主要冲突。

代理成本理论认为,如何达到平衡这两种类型的冲突,资本结构是如何形成的,这是比前两次在一定程度上更多的理论更全面。

……Agency Cost under the Restriction of Free Cash FlowAbstractAgency cost theory is an important branch of capital structural theory. Free cash flow has significant impact on agency cost. The combination of research on these two fields would help to build and extend the theoretical system. Based on agency cost theory, the present study firstly categorized the characteristics of free cash flow as well as the statistical methodologies. Furthermore, the existence of investing free cash flow in agency cost was proved by a model. Then free cash flow was introduced into agency cost theory as restriction, the analysis shows that it will change agency cost, in turn, will have an impact on the relationship between agency cost and capital structure, finally, will influence the optimal capital structure point to maintain the equilibrium. Concretely, with the increasing free cash flow, correspondingly, debt proportion will decrease.Keywords:Capital Structure,Free Cash Flow,Agency Cost,Non-Pecuniary Benefit1. IntroductionAgency cost theory, financial contract theory, signaling model and new pecking order theory are the main branches of new capital structure theory. Financial con-tract theory focuses on restricting stockholders’ behavior by contract and solving the conflict between stockholders and creditors. Signaling model and new pecking order theory center on solving the conflict between investors and managers. These two types of conflict are the main conflict in business organizations. Agency cost theory considers how equilibrium is reached in both types of conflict and how capital structure is formed, which is more theory is more comprehensive than the previous two to some degree.……。

毕业设计论文外文文献翻译智能交通信号灯控制中英文对照

毕业设计论文外文文献翻译智能交通信号灯控制中英文对照

英语原文Intelligent Traffic Light Controlby Marco Wiering The topic I picked for our community project was traffic lights. In a community, people need stop signs and traffic lights to slow down drivers from going too fast. If there were no traffic lights or stop signs, people’s lives would be in danger from drivers going too fast.The urban traffic trends towards the saturation, the rate of increase of the road of big city far lags behind rate of increase of the car.The urban passenger traffic has already become the main part of city traffic day by day and it has used about 80% of the area of road of center district. With the increase of population and industry activity, people's traffic is more and more frequent, which is unavoidable. What means of transportation people adopt produces pressure completely different to city traffic. According to calculating, if it is 1 to adopt the area of road that the public transport needs, bike needs 5-7, car needs 15-25, even to walk is 3 times more than to take public transits. So only by building road can't solve the city traffic problem finally yet. Every large city of the world increases the traffic policy to the first place of the question.For example,according to calculating, when the automobile owning amount of Shanghai reaches 800,000 (outside cars count separately ), if it distributes still as now for example: center district accounts for great proportion, even when several loop-lines and arterial highways have been built up , the traffic cannot be improved more than before and the situation might be even worse. So the traffic policy Shanghai must adopt , or called traffic strategy is that have priority to develop public passenger traffic of city, narrow the scope of using of the bicycle progressively , control the scale of growth of the car traffic in the center district, limit the development of the motorcycle strictly.There are more municipals project under construction in big city. the influence on the traffic is greater.Municipal infrastructure construction is originally a good thing of alleviating the traffic, but in the course of constructing, it unavoidably influence the local traffic. Some road sections are blocked, some change into an one-way lane, thus the vehicle can only take a devious route . The construction makes the road very narrow, forming the bottleneck, which seriously influence the car flow.When having stop signs and traffic lights, people have a tendency to drive slower andlook out for people walking in the middle of streets. To put a traffic light or a stop sign in a community, it takes a lot of work and planning from the community and the city to put one in. It is not cheap to do it either. The community first needs to take a petition around to everyone in the community and have them sign so they can take it to the board when the next city council meeting is. A couple residents will present it to the board, and they will decide weather or not to put it in or not. If not put in a lot of residents might be mad and bad things could happened to that part of the city.When the planning of putting traffic lights and stop signs, you should look at the subdivision plan and figure out where all the buildings and schools are for the protection of students walking and riding home from school. In our plan that we have made, we will need traffic lights next to the school, so people will look out for the students going home. We will need a stop sign next to the park incase kids run out in the street. This will help the protection of the kids having fun. Will need a traffic light separating the mall and the store. This will be the busiest part of the town with people going to the mall and the store. And finally there will need to be a stop sign at the end of the streets so people don’t drive too fast and get in a big accident. If this is down everyone will be safe driving, walking, or riding their bikes.In putting in a traffic light, it takes a lot of planning and money to complete it. A traffic light cost around $40,000 to $125,000 and sometimes more depending on the location. If a business goes in and a traffic light needs to go in, the business or businesses will have to pay some money to pay for it to make sure everyone is safe going from and to that business. Also if there is too many accidents in one particular place in a city, a traffic light will go in to safe people from getting a severe accident and ending their life and maybe someone else’s.The reason I picked this part of our community development report was that traffic is a very important part of a city. If not for traffic lights and stop signs, people’s lives would be in danger every time they walked out their doors. People will be driving extremely fast and people will be hit just trying to have fun with their friends. So having traffic lights and stop signs this will prevent all this from happening.Traffic in a city is very much affected by traffic light controllers. When waiting for a traffic light, the driver looses time and the car uses fuel. Hence, reducing waiting times before traffic lights can save our European society billions of Euros annually. To make traffic light controllers more intelligent, we exploit the emergence of novel technologies such as communication networks and sensor networks, as well as the use of more sophisticated algorithms for setting traffic lights. Intelligent traffic light control does not only mean thattraffic lights are set in order to minimize waiting times of road users, but also that road users receive information about how to drive through a city in order to minimize their waiting times. This means that we are coping with a complex multi-agent system, where communication and coordination play essential roles. Our research has led to a novel system in which traffic light controllers and the behaviour of car drivers are optimized using machine-learning methods.Our idea of setting a traffic light is as follows. Suppose there are a number of cars with their destination address standing before a crossing. All cars communicate to the traffic light their specific place in the queue and their destination address. Now the traffic light has to decide which option (ie, which lanes are to be put on green) is optimal to minimize the long-term average waiting time until all cars have arrived at their destination address. The learning traffic light controllers solve this problem by estimating how long it would take for a car to arrive at its destination address (for which the car may need to pass many different traffic lights) when currently the light would be put on green, and how long it would take if the light would be put on red. The difference between the waiting time for red and the waiting time for green is the gain for the car. Now the traffic light controllers set the lights in such a way to maximize the average gain of all cars standing before the crossing. To estimate the waiting times, we use 'reinforcement learning' which keeps track of the waiting times of individual cars and uses a smart way to compute the long term average waiting times using dynamic programming algorithms. One nice feature is that the system is very fair; it never lets one car wait for a very long time, since then its gain of setting its own light to green becomes very large, and the optimal decision of the traffic light will set his light to green. Furthermore, since we estimate waiting times before traffic lights until the destination of the road user has been reached, the road user can use this information to choose to which next traffic light to go, thereby improving its driving behaviour through a city. Note that we solve the traffic light control problem by using a distributed multi-agent system, where cooperation and coordination are done by communication, learning, and voting mechanisms. To allow for green waves during extremely busy situations, we combine our algorithm with a special bucket algorithm which propagates gains from one traffic light to the next one, inducing stronger voting on the next traffic controller option.We have implemented the 'Green Light District', a traffic simulator in Java in which infrastructures can be edited easily by using the mouse, and different levels of road usage can be simulated. A large number of fixed and learning traffic light controllers have already been tested in the simulator and the resulting average waiting times of cars have been plotted and compared. The results indicate that the learning controllers can reduce average waiting timeswith at least 10% in semi-busy traffic situations, and even much more when high congestion of the traffic occurs.We are currently studying the behaviour of the learning traffic light controllers on many different infrastructures in our simulator. We are also planning to cooperate with other institutes and companies in the Netherlands to apply our system to real world traffic situations. For this, modern technologies such as communicating networks can be brought to use on a very large scale, making the necessary communication between road users and traffic lights possible.中文翻译:智能交通信号灯控制马克·威宁我所选择的社区项目主题是交通灯。

毕业设计英文翻译中英文对照版

毕业设计英文翻译中英文对照版

Feasibility assessment of a leading-edge-flutter wind power generator前缘颤振风力发电机的可行性评估Luca Caracoglia卢卡卡拉克格里亚Department of Civil and Environmental Engineering, Northeastern University, 400 Snell Engineering Center, 360 Huntington A venue, Boston, MA 02115, USA美国东北大学土木与环境工程斯内尔工程中心400,亨廷顿大道360,波士顿02115This study addresses the preliminary technical feasibility assessment of a mechanical apparatus for conversion of wind energy. 这项研究涉及的是风能转换的机械设备的初步技术可行性评估。

The proposed device, designated as ‘‘leading-edge-fl utter wind power generator’’, employs aeroelastic dynamic instability of a blade airfoil, torsionally rotating about its leading edge. 这种被推荐的定义为“前缘颤振风力发电机”的设备,采用的气动弹性动态不稳定叶片翼型,通过尖端旋转产生扭矩。

Although the exploitation of aeroelastic phenomena has been proposed by the research community for energy harvesting, this apparatus is compact, simple and marginally susceptible to turbulence and wake effects.虽然气动弹性现象的开发已经有研究界提出可以通过能量采集。

机械设计制造及其自动化毕业论文中英文资料外文翻译

机械设计制造及其自动化毕业论文中英文资料外文翻译

机械设计创造及其自动化毕业论文外文文献翻译INTEGRATION OF MACHINERY译文题目专业机械设计创造及其自动化外文资料翻译INTEGRATION OF MACHINERY(From ELECTRICAL AND MACHINERY INDUSTRY)ABSTRACTMachinery was the modern science and technology development inevitable result, this article has summarized the integration of machinery technology basic outline and the development background .Summarized the domestic and foreign integration of machinery technology present situation, has analyzed the integration of machinery technology trend of development.Key word: integration of machinery ,technology, present situation ,product t,echnique of manufacture ,trend of development0. Introduction modern science and technology unceasing development, impelled different discipline intersecting enormously with the seepage, has caused the project domain technological revolution and the transformation .In mechanical engineering domain, because the microelectronic technology and the computer technology rapid development and forms to the mechanical industry seepage the integration of machinery, caused the mechanical industry the technical structure, the product organization, the function and the constitution, the production method and the management systemof by machinery for the characteristic integration ofdevelopment phase.1. Integration of machinery outline integration of machinery is refers in the organization new owner function, the power function, in the information processing function and the control function introduces the electronic technology, unifies the system the mechanism and the computerization design and the software which constitutes always to call. The integration of machinery development also has become one to have until now own system new discipline, not only develops along with the science and technology, but also entrusts with the new content .But its basic characteristic may summarize is: The integration of machinery is embarks from the system viewpoint, synthesis community technologies and so on utilization mechanical technology, microelectronic technology, automatic control technology, computer technology, information technology, sensing observation and control technology, electric power electronic technology, connection technology, information conversion technology as well as software programming technology, according to the system function goal and the optimized organization goal, reasonable disposition and the layout various functions unit, in multi-purpose, high grade, redundant reliable, in the low energy consumption significance realize the specific function value, and causes the overall system optimization the systems engineering technology .From this produces functional system, then becomes an integration of machinery systematic or the integration of machinery product. Therefore, of coveringtechnology is based on the above community technology organic fusion one kind of comprehensive technology, but is not mechanical technical, the microelectronic technology as well as other new technical simple combination, pieces together .This is the integration of machinery and the machinery adds the machinery electrification which the electricity forms in the concept basic difference .The mechanical engineering technology has the merely technical to develop the machinery electrification, still was the traditional machinery, its main function still was replaces with the enlargement physical strength .But after develops the integration of machinery, micro electron installment besides may substitute for certain mechanical parts the original function, but also can entrust with many new functions,like the automatic detection, the automatic reduction information, demonstrate the record, the automatic control and the control automatic diagnosis and the protection automatically and so on .Not only namely the integration of machinery product is human's hand and body extending, human's sense organ and the brains look, has the intellectualized characteristic is the integration of machinery and the machinery electrification distinguishes in the function essence.2. Integration of machinery development condition integration of machinery development may divide into 3 stages roughly.20th century 60's before for the first stage, this stage is called the initial stage .In this time, the people determination not on own initiative uses the electronic technology the preliminary achievement to consummate the mechanical product the performance .Specially in Second World War period, the war has stimulated the mechanical product and the electronic technology union, these mechanical and electrical union military technology, postwar transfers civilly, to postwar economical restoration positive function .Developed and the development at that time generally speaking also is at the spontaneouscondition .Because at that time the electronic technology development not yet achieved certain level, mechanical technical and electronic technology union also not impossible widespread and thorough development, already developed the product was also unable to promote massively. The 20th century 70~80 ages for the second stage, may be called the vigorous development stage .This time, the computer technology, the control technology, the communication development, has laid the technology base for the integration of machinery development . Large-scale, ultra large scale integrated circuit and microcomputer swift and violent development, has provided the full material base for the integration of machinery development .This time characteristic is :①A mechatronics word first generally is accepted in Japan, probably obtains the quite widespread acknowledgment to 1980s last stages in the worldwide scale ;②The integration of machinery technology and the product obtained the enormous development ;③The various countries start to the integration of machinery technology and the product give the very big attention and the support. 1990s later periods, started the integration of machinery technology the new stagewhich makes great strides forward to the intellectualized direction, the integration of machinery enters the thorough development time .At the same time, optics, the communication and so on entered the integration of machinery, processes the technology also zhan to appear tiny in the integration of machinery the foot, appeared the light integration of machinery and the micro integration of machinery and so on the new branch; On the other hand to the integration of machinery system modeling design, the analysis and the integrated method, the integration of machinery discipline system and the trend of development has all conducted the thorough research .At the same time, because the hugeprogress which domains and so on artificial intelligence technology, neural network technology and optical fiber technology obtain, opened the development vast world for the integration of machinery technology .These research, will urge the integration of machinery further to establish the integrity the foundation and forms the integrity gradually the scientific system. Our country is only then starts from the beginning of 1980s in this aspect to study with the application .The State Councilsummary had considered fully on international the influence which and possibly brought from this about the integration of machinery technology developmenttrend .Many universities, colleges and institutes, the development facility and some large and middle scale enterprises have done the massive work to this technical development and the application, does not yield certain result, but and so on the advanced countries compared with Japan still has the suitable disparity.3. Integration of machinery trend of development integrations of machinery are the collection machinery, the electron, optics, the control, the computer, the information and so on the multi-disciplinary overlapping syntheses, its development and the progress rely on and promote the correlation technology development and the progress .Therefore, the integration of machinery main development direction is as follows:3.1 Intellectualized intellectualizations are 21st century integration of machinery technological development important development directions .Theartificial intelligence obtains day by day in the integration of machinery constructor's research takes, the robot and the numerical control engine bedis to the machine behavior description, is in the control theory foundation, the absorption artificial intelligence, the operations research, the computer science, the fuzzy mathematics, the psychology, the physiology and the chaos dynamics and so on the new thought, the new method, simulate the human intelligence, enable it to have abilities and so on judgment inference, logical thinking, independent decision-making, obtains the higher control goal in order to .Indeed, enable the integration of machinery product to have with the human identical intelligence, is not impossible, also is nonessential .But, the high performance, the high speed microprocessor enable the integration of machinery product to have preliminary intelligent or human's partial intelligences, then is completely possible and essential.In the modern manufacture process, the information has become the control manufacture industry the determining factor, moreover is the most active actuation factor .Enhances the manufacture system information-handling capacity to become the modern manufacture science development a key point .As a result of the manufacture system information organization and structure multi-level, makes the information the gain, the integration and the fusion presents draws up the character, information measure multi-dimensional, as well as information organization's multi-level .In the manufacture information structural model, manufacture information uniform restraint, dissemination processing and magnanimous data aspects and so on manufacture knowledge library management, all also wait for further break through.Each kind of artificial intelligence tool and the computation intelligence method promoted the manufacture intelligence development in the manufacture widespread application .A kind based on the biological evolution algorithm computation intelligent agent, in includes thescheduling problem in the combination optimization solution area of technology, receives the more and more universal attention, hopefully completes the combination optimization question when the manufacture the solution speed and the solution precision aspect breaks through the question scale in pairs the restriction .The manufacture intelligence also displays in: The intelligent dispatch, the intelligent design, the intelligent processing, the robot study, the intelligent control, the intelligent craft plan, the intelligent diagnosis and so on are various These question key breakthrough, may form the product innovation the basic research system. Between 2 modern mechanical engineering front science different science overlapping fusion will have the new science accumulation, the economical development and society's progress has had the new request and the expectation to the science and technology, thus will form the front science .The front science also has solved and between the solution scientific question border area .The front science has the obvious time domain, the domain and the dynamic characteristic .The project front science distinguished in the general basic science important characteristic is it has covered the key science and technology question which the project actual appeared.Manufacture system is a complex large-scale system, for satisfies the manufacture system agility, the fast response and fast reorganization ability, must profit from the information science, the life sciences and the social sciences and so on the multi-disciplinary research results, the exploration manufacture system new architecture, the manufacture pattern and the manufacture system effective operational mechanism .Makes the system optimization the organizational structure and the good movement condition is makes the system modeling , the simulation and the optimized essential target .Not only the manufacture system new architecture to makes the enterprise the agility and may reorganize ability to the demand response ability to have the vital significance, moreover to made the enterprise first floor production equipment the flexibility and may dynamic reorganization ability set a higher request .The biological manufacture view more and more many is introduced the manufacture system, satisfies the manufacture system new request.The study organizes and circulates method and technique of complicated system from the biological phenomenon, is a valid exit which will solve many hard nut to cracks that manufacturing industry face from now on currently .Imitating to living what manufacturing point is mimicry living creature organ of from the organization, from match more, from growth with from evolution etc. function structure and circulate mode of a kind of manufacturing system and manufacturing process.The manufacturing drives in the mechanism under, continuously by one's own perfect raise on organizing structure and circulating mode and thus to adapt the process of[with] ability for the environment .For from descend but the last product proceed together a design and make a craft rules the auto of the distance born, produce system of dynamic state reorganization and product and manufacturing the system tend automatically excellent provided theories foundation and carry out acondition .Imitate to living a manufacturing to belong to manufacturing science and life science of"the far good luck is miscellaneous to hand over", it will produce to the manufacturing industry for 21 centuries huge of influence .机电一体化摘要机电一体化是现代科学技术发展的必然结果,本文简述了机电一体化技术的基本概要和发展背景。

论文英文翻译最终版

论文英文翻译最终版

序号(学号):040940131长春光华学院毕业设计(论文)译文Electronic technique电子技术姓名盛遵义教学院电气信息学院专业电子信息工程班级电信09401指导教师张淑艳(讲师)2013 年04 月10 日┊┊┊┊┊┊┊┊┊┊┊┊┊装┊┊┊┊┊订┊┊┊┊┊线┊┊┊┊┊┊┊┊┊┊┊┊┊Electronic techniqueFrom the world of radio in the world to a single chip, modern computer technology, industrial revolution, the world economy from the capital into the economy to knowledge economy。

Field in the electronic world, from the 20th century into the era of radio to computer technology in the 21st century as the center of the intelligent modern era of electronic systems。

The basic core of modern electronic systems are embedded computer systems (referred to as embedded systems), while the microcontroller is the most typical and most extensive and most popular embedded systems。

radio has created generations of excellence in the world Fifties and sixties in the 20th century,the most representative of the advanced electronic technology is wireless technology, including radio broadcasting, radio,wireless communications (telegraph),Amateur Radio, radio positioning,navigation and other telemetry, remote control, remote technology。

建筑设计毕业论文中英文资料外文翻译文献

建筑设计毕业论文中英文资料外文翻译文献

毕业论文中英文资料外文翻译文献Architecture StructureWe have and the architects must deal with the spatial aspect of activity, physical, and symbolic needs in such a way that overall performance integrity is assured. Hence, he or she well wants to think of evolving a building environment as a total system of interacting and space forming subsystems. Is represents a complex challenge, and to meet it the architect will need a hierarchic design process that provides at least three levels of feedback thinking: schematic, preliminary, and final.Such a hierarchy is necessary if he or she is to avoid being confused , at conceptual stages of design thinking ,by the myriad detail issues that can distract attention from more basic consideration s .In fact , we can say that an architect’s ability to distinguish the more basic form the more detailed issues is essential to his success as a designer .The object of the schematic feed back level is to generate and evaluate overall site-plan, activity-interaction, and building-configuration options .To do so the architect must be able to focus on the interaction of the basic attributes of the site context, the spatial organization, and the symbolism as determinants of physical form. This means that ,in schematic terms ,the architect may first conceive and model a building design as an organizational abstraction of essential performance-space in teractions.Then he or she may explore the overall space-form implications of the abstraction. As an actual building configuration option begins to emerge, it will be modified to include consideration for basic site conditions.At the schematic stage, it would also be helpful if the designer could visualize his or her options for achieving overall structural integrity and consider the constructive feasibility and economic of his or her scheme .But this will require that the architect and/or a consultant be able to conceptualize total-system structural options in terms of elemental detail .Such overall thinking can be easily fed back to improve the space-form scheme.At the preliminary level, the architect’s emphasis will shift to the elaboration of his or her more promising schematic design options .Here the architect’s structural needs will shift toapproximate design of specific subsystem options. At this stage the total structural scheme is developed to a middle level of specificity by focusing on identification and design of major subsystems to the extent that their key geometric, component, and interactive properties are established .Basic subsystem interaction and design conflicts can thus be identified and resolved in the context of total-system objectives. Consultants can play a significant part in this effort; these preliminary-level decisions may also result in feedback that calls for refinement or even major change in schematic concepts.When the designer and the client are satisfied with the feasibility of a design proposal at the preliminary level, it means that the basic problems of overall design are solved and details are not likely to produce major change .The focus shifts again ,and the design process moves into the final level .At this stage the emphasis will be on the detailed development of all subsystem specifics . Here the role of specialists from various fields, including structural engineering, is much larger, since all detail of the preliminary design must be worked out. Decisions made at this level may produce feedback into Level II that will result in changes. However, if Levels I and II are handled with insight, the relationship between the overall decisions, made at the schematic and preliminary levels, and the specifics of the final level should be such that gross redesign is not in question, Rather, the entire process should be one of moving in an evolutionary fashion from creation and refinement (or modification) of the more general properties of a total-system design concept, to the fleshing out of requisite elements and details.To summarize: At Level I, the architect must first establish, in conceptual terms, the overall space-form feasibility of basic schematic options. At this stage, collaboration with specialists can be helpful, but only if in the form of overall thinking. At Level II, the architect must be able to identify the major subsystem requirements implied by the scheme and substantial their interactive feasibility by approximating key component properties .That is, the properties of major subsystems need be worked out only in sufficient depth to very the inherent compatibility of their basic form-related and behavioral interaction . This will mean a somewhat more specific form of collaboration with specialists then that in level I .At level III ,the architect and the specific form of collaboration with specialists then that providing for all of the elemental design specifics required to produce biddable construction documents .Of course this success comes from the development of the Structural Material.1.Reinforced ConcretePlain concrete is formed from a hardened mixture of cement ,water ,fine aggregate, coarse aggregate (crushed stone or gravel),air, and often other admixtures. The plastic mix is placed and consolidated in the formwork, then cured to facilitate the acceleration of the chemical hydration reaction lf the cement/water mix, resulting in hardened concrete. The finished product has high compressive strength, and low resistance to tension, such that its tensile strength is approximately one tenth lf its compressive strength. Consequently, tensile and shear reinforcement in the tensile regions of sections has to be provided to compensate for the weak tension regions in the reinforced concrete element.It is this deviation in the composition of a reinforces concrete section from the homogeneity of standard wood or steel sections that requires a modified approach to the basic principles of structural design. The two components of the heterogeneous reinforced concrete section are to be so arranged and proportioned that optimal use is made of the materials involved. This is possible because concrete can easily be given any desired shape by placing and compacting the wet mixture of the constituent ingredients are properly proportioned, the finished product becomes strong, durable, and, in combination with the reinforcing bars, adaptable for use as main members of any structural system.The techniques necessary for placing concrete depend on the type of member to be cast: that is, whether it is a column, a bean, a wall, a slab, a foundation. a mass columns, or an extension of previously placed and hardened concrete. For beams, columns, and walls, the forms should be well oiled after cleaning them, and the reinforcement should be cleared of rust and other harmful materials. In foundations, the earth should be compacted and thoroughly moistened to about 6 in. in depth to avoid absorption of the moisture present in the wet concrete. Concrete should always be placed in horizontal layers which are compacted by means of high frequency power-driven vibrators of either the immersion or external type, as the case requires, unless it is placed by pumping. It must be kept in mind, however, that over vibration can be harmful since it could cause segregation of the aggregate and bleeding of the concrete.Hydration of the cement takes place in the presence of moisture at temperatures above 50°F. It is necessary to maintain such a condition in order that the chemical hydration reaction can take place. If drying is too rapid, surface cracking takes place. This would result in reduction of concrete strength due to cracking as well as the failure to attain full chemical hydration.It is clear that a large number of parameters have to be dealt with in proportioning a reinforced concrete element, such as geometrical width, depth, area of reinforcement, steel strain, concrete strain, steel stress, and so on. Consequently, trial and adjustment is necessary in the choice ofconcrete sections, with assumptions based on conditions at site, availability of the constituent materials, particular demands of the owners, architectural and headroom requirements, the applicable codes, and environmental reinforced concrete is often a site-constructed composite, in contrast to the standard mill-fabricated beam and column sections in steel structures.A trial section has to be chosen for each critical location in a structural system. The trial section has to be analyzed to determine if its nominal resisting strength is adequate to carry the applied factored load. Since more than one trial is often necessary to arrive at the required section, the first design input step generates into a series of trial-and-adjustment analyses.The trial-and –adjustment procedures for the choice of a concrete section lead to the convergence of analysis and design. Hence every design is an analysis once a trial section is chosen. The availability of handbooks, charts, and personal computers and programs supports this approach as a more efficient, compact, and speedy instructional method compared with the traditional approach of treating the analysis of reinforced concrete separately from pure design.2. EarthworkBecause earthmoving methods and costs change more quickly than those in any other branch of civil engineering, this is a field where there are real opportunities for the enthusiast. In 1935 most of the methods now in use for carrying and excavating earth with rubber-tyred equipment did not exist. Most earth was moved by narrow rail track, now relatively rare, and the main methods of excavation, with face shovel, backacter, or dragline or grab, though they are still widely used are only a few of the many current methods. To keep his knowledge of earthmoving equipment up to date an engineer must therefore spend tine studying modern machines. Generally the only reliable up-to-date information on excavators, loaders and transport is obtainable from the makers.Earthworks or earthmoving means cutting into ground where its surface is too high ( cuts ), and dumping the earth in other places where the surface is too low ( fills). Toreduce earthwork costs, the volume of the fills should be equal to the volume of the cuts and wherever possible the cuts should be placednear to fills of equal volume so as to reduce transport and double handlingof the fill. This work of earthwork design falls on the engineer who lays out the road since it is the layout of the earthwork more than anything else which decides its cheapness. From the available maps ahd levels, the engineering must try to reach as many decisions as possible in the drawing office by drawing cross sections of the earthwork. On the site when further information becomes available he can make changes in jis sections and layout,but the drawing lffice work will not have been lost. It will have helped him to reach the best solution in the shortest time.The cheapest way of moving earth is to take it directly out of the cut and drop it as fill with the same machine. This is not always possible, but when it canbe done it is ideal, being both quick and cheap. Draglines, bulldozers and face shovels an do this. The largest radius is obtained with thedragline,and the largest tonnage of earth is moved by the bulldozer, though only over short distances.The disadvantages of the dragline are that it must dig below itself, it cannot dig with force into compacted material, it cannot dig on steep slopws, and its dumping and digging are not accurate.Face shovels are between bulldozers and draglines, having a larger radius of action than bulldozers but less than draglines. They are anle to dig into a vertical cliff face in a way which would be dangerous tor a bulldozer operator and impossible for a dragline. Each piece of equipment should be level of their tracks and for deep digs in compact material a backacter is most useful, but its dumping radius is considerably less than that of the same escavator fitted with a face shovel.Rubber-tyred bowl scrapers are indispensable for fairly level digging where the distance of transport is too much tor a dragline or face shovel. They can dig the material deeply ( but only below themselves ) to a fairly flat surface, carry it hundreds of meters if need be, then drop it and level it roughly during the dumping. For hard digging it is often found economical to keep a pusher tractor ( wheeled or tracked ) on the digging site, to push each scraper as it returns to dig. As soon as the scraper is full,the pusher tractor returns to the beginning of the dig to heop to help the nest scraper.Bowl scrapers are often extremely powerful machines;many makers build scrapers of 8 cubic meters struck capacity, which carry 10 m ³ heaped. The largest self-propelled scrapers are of 19 m ³struck capacity ( 25 m ³ heaped )and they are driven by a tractor engine of 430 horse-powers.Dumpers are probably the commonest rubber-tyred transport since they can also conveniently be used for carrying concrete or other building materials. Dumpers have the earth container over the front axle on large rubber-tyred wheels, and the container tips forwards on most types, though in articulated dumpers the direction of tip can be widely varied. The smallest dumpers have a capacity of about 0.5 m ³, and the largest standard types are of about 4.5 m ³. Special types include the self-loading dumper of up to 4 m ³ and the articulated type of about 0.5 m ³. The distinction between dumpers and dump trucks must be remembered .dumpers tip forwards and the driver sits behind the load. Dump trucks are heavy, strengthened tipping lorries, the driver travels in front lf the load and the load is dumped behind him, so they are sometimes called rear-dump trucks.3.Safety of StructuresThe principal scope of specifications is to provide general principles and computational methods in order to verify safety of structures. The “ safety factor ”, which according to modern trends is independent of the nature and combination of the materials used, can usually be defined as the ratio between the conditions. This ratio is also proportional to the inverse of the probability ( risk ) of failure of the structure.Failure has to be considered not only as overall collapse of the structure but also asunserviceability or, according to a more precise. Common definition. As the reaching of a “ limit state ” which causes the construction not to accomplish the task it was designed for. Ther e are two categories of limit state :(1)Ultimate limit sate, which corresponds to the highest value of the load-bearing capacity. Examples include local buckling or global instability of the structure; failure of some sections and subsequent transformation of the structure into a mechanism; failure by fatigue; elastic or plastic deformation or creep that cause a substantial change of the geometry of the structure; and sensitivity of the structure to alternating loads, to fire and to explosions.(2)Service limit states, which are functions of the use and durability of the structure. Examples include excessive deformations and displacements without instability; early or excessive cracks; large vibrations; and corrosion.Computational methods used to verify structures with respect to the different safety conditions can be separated into:(1)Deterministic methods, in which the main parameters are considered as nonrandom parameters.(2)Probabilistic methods, in which the main parameters are considered as random parameters.Alternatively, with respect to the different use of factors of safety, computational methods can be separated into:(1)Allowable stress method, in which the stresses computed under maximum loads are compared with the strength of the material reduced by given safety factors.(2)Limit states method, in which the structure may be proportioned on the basis of its maximum strength. This strength, as determined by rational analysis, shall not be less than that required to support a factored load equal to the sum of the factored live load and dead load ( ultimate state ).The stresses corresponding to working ( service ) conditions with unfactored live and dead loads are compared with prescribed values ( service limit state ) . From the four possible combinations of the first two and second two methods, we can obtain some useful computational methods. Generally, two combinations prevail:(1)deterministic methods, which make use of allowable stresses.(2)Probabilistic methods, which make use of limit states.The main advantage of probabilistic approaches is that, at least in theory, it is possible to scientifically take into account all random factors of safety, which are then combined to define the safety factor. probabilistic approaches depend upon :(1) Random distribution of strength of materials with respect to the conditions of fabrication and erection ( scatter of the values of mechanical properties through out the structure );(2) Uncertainty of the geometry of the cross-section sand of the structure ( faults andimperfections due to fabrication and erection of the structure );(3) Uncertainty of the predicted live loads and dead loads acting on the structure;(4)Uncertainty related to the approximation of the computational method used ( deviation of the actual stresses from computed stresses ).Furthermore, probabilistic theories mean that the allowable risk can be based on several factors, such as :(1) Importance of the construction and gravity of the damage by its failure;(2)Number of human lives which can be threatened by this failure;(3)Possibility and/or likelihood of repairing the structure;(4) Predicted life of the structure.All these factors are related to economic and social considerations such as:(1) Initial cost of the construction;(2) Amortization funds for the duration of the construction;(3) Cost of physical and material damage due to the failure of the construction;(4) Adverse impact on society;(5) Moral and psychological views.The definition of all these parameters, for a given safety factor, allows construction at the optimum cost. However, the difficulty of carrying out a complete probabilistic analysis has to be taken into account. For such an analysis the laws of the distribution of the live load and its induced stresses, of the scatter of mechanical properties of materials, and of the geometry of the cross-sections and the structure have to be known. Furthermore, it is difficult to interpret the interaction between the law of distribution of strength and that of stresses because both depend upon the nature of the material, on the cross-sections and upon the load acting on the structure. These practical difficulties can be overcome in two ways. The first is to apply different safety factors to the material and to the loads, without necessarily adopting the probabilistic criterion. The second is an approximate probabilistic method which introduces some simplifying assumptions ( semi-probabilistic methods ) .文献翻译建筑师必须从一种全局的角度出发去处理建筑设计中应该考虑到的实用活动,物质及象征性的需求。

毕业设计外文文献翻译

毕业设计外文文献翻译

毕业设计外文文献翻译Graduation Design Foreign Literature Translation (700 words) Title: The Impact of Artificial Intelligence on the Job Market Introduction:Artificial Intelligence (AI) is a rapidly growing field that has the potential to revolutionize various industries and job markets. With advancements in technologies such as machine learning and natural language processing, AI has become capable of performing tasks traditionally done by humans. This has raised concerns about the future of jobs and the impact AI will have on the job market. This literature review aims to explore the implications of AI on employment and job opportunities.AI in the Workplace:AI technologies are increasingly being integrated into the workplace, with the aim of automating routine and repetitive tasks. For example, automated chatbots are being used to handle customer service queries, while machine learning algorithms are being employed to analyze large data sets. This has resulted in increased efficiency and productivity in many industries. However, it has also led to concerns about job displacement and unemployment.Job Displacement:The rise of AI has raised concerns about job displacement, as AI technologies are becoming increasingly capable of performing tasks previously done by humans. For example, automated machines can now perform complex surgeries with greaterprecision than human surgeons. This has led to fears that certain jobs will become obsolete, leading to unemployment for those who were previously employed in these industries.New Job Opportunities:While AI might potentially replace certain jobs, it also creates new job opportunities. As AI technologies continue to evolve, there will be a greater demand for individuals with technical skills in AI development and programming. Additionally, jobs that require human interaction and emotional intelligence, such as social work or counseling, may become even more in demand, as they cannot be easily automated.Job Transformation:Another potential impact of AI on the job market is job transformation. AI technologies can augment human abilities rather than replacing them entirely. For example, AI-powered tools can assist professionals in making decisions, augmenting their expertise and productivity. This may result in changes in job roles and the need for individuals to adapt their skills to work alongside AI technologies.Conclusion:The impact of AI on the job market is still being studied and debated. While AI has the potential to automate certain tasks and potentially lead to job displacement, it also presents opportunities for new jobs and job transformation. It is essential for individuals and organizations to adapt and acquire the necessary skills to navigate these changes in order to stay competitive in the evolvingjob market. Further research is needed to fully understand the implications of AI on employment and job opportunities.。

液压专业毕业设计外文翻译(有译文、外文文献)值得收藏哦!

液压专业毕业设计外文翻译(有译文、外文文献)值得收藏哦!

外文原文:The Analysis of Cavitation Problems in the Axial Piston Pumpshu WangEaton Corporation,14615 Lone Oak Road,Eden Prairie, MN 55344This paper discusses and analyzes the control volume of a piston bore constrained by the valve plate in axial piston pumps. The vacuum within the piston bore caused by the rise volume needs to be compensated by the flow; otherwise, the low pressure may cause the cavitations and aerations. In the research, the valve plate geometry can be optimized by some analytical limitations to prevent the piston pressure below the vapor pressure. The limitations provide the design guide of the timings and overlap areas between valve plate ports and barrel kidneys to consider the cavitations and aerations. _DOI: 10.1115/1.4002058_Keywords: cavitation , optimization, valve plate, pressure undershoots1 IntroductionIn hydrostatic machines, cavitations mean that cavities or bubbles form in the hydraulic liquid at the low pressure and collapse at the high pressure region, which causes noise, vibration, and less efficiency.Cavitations are undesirable in the pump since the shock waves formed by collapsed may be strong enough to damage components. The hydraulic fluid will vaporize when its pressure becomes too low or when the temperature is too high. In practice, a number of approaches are mostly used to deal with the problems: (1) raise the liquid level in the tank, (2) pressurize the tank, (3) booster the inlet pressure of the pump, (4) lower the pumping fluid temperature, and (5) design deliberately the pump itself.Many research efforts have been made on cavitation phenomena in hydraulic machine designs. The cavitation is classified into two types in piston pumps: trapping phenomenon related one (which can be preventedby the proper design of the valve plate) and the one observed on the layers after the contraction or enlargement of flow passages (caused by rotating group designs) in Ref. (1). The relationship between the cavitation and the measured cylinder pressure is addressed in this study. Edge and Darling (2) reported an experimental study of the cylinder pressure within an axial piston pump. The inclusion of fluid momentum effects and cavitations within the cylinder bore are predicted at both high speed and high load conditions. Another study in Ref. (3) provides an overview of hydraulic fluid impacting on the inlet condition and cavitation potential. It indicates that physical properties (such as vapor pressure, viscosity, density, and bulk modulus) are vital to properly evaluate the effects on lubrication and cavitation. A homogeneous cavitation model based on the thermodynamic properties of the liquid and steam is used to understand the basic physical phenomena of mass flow reduction and wave motion influences in the hydraulic tools and injection systems (4). Dular et al. (5, 6) developed an expert system for monitoring and control of cavitations in hydraulic machines and investigated the possibility of cavitation erosion by using the computational fluid dynamics (CFD) tools. The erosion effects of cavitations have been measured and validated by a simple single hydrofoil configuration in a cavitation tunnel. It is assumed that the severe erosion is often due to the repeated collapse of the traveling vortex generated by a leading edge cavity in Ref. (7). Then, the cavitation erosion intensity may be scaled by a simple set of flow parameters: the upstream velocity, the Strouhal number, the cavity length, and the pressure. A new cavitation erosion device, called vortex cavitation generator, is introduced to comparatively study various erosion situations (8).More previous research has been concentrated on the valve plate designs, piston, and pump pressure dynamics that can be associated with cavitations in axial piston pumps. The control volume approach and instantaneous flows (leakage) are profoundly studied in Ref. [9]. Berta et al. [10] used the finite volume concept to develop a mathematical model in which the effects of port plate relief grooves have been modeled andthe gaseous cavitation is considered in a simplified manner. An improved model is proposed in Ref. [11] and validated by experimental results. The model may analyze the cylinder pressure and flow ripples influenced by port plate and relief groove design. Manring compared principal advantages of various valve plate slots (i.e., the slots with constant, linearly varying, and quadratic varying areas) in axial piston pumps [12]. Four different numerical models are focused on the characteristics of hydraulic fluid, and cavitations are taken into account in different ways to assist the reduction in flow oscillations [13].The experiences of piston pump developments show that the optimization of the cavitations/aerations shall include the following issues: occurring cavitation and air release, pump acoustics caused by the induced noises, maximal amplitudes of pressure fluctuations, rotational torque progression, etc. However, the aim of this study is to modify the valve plate design to prevent cavitation erosions caused by collapsing steam or air bubbles on the walls of axial pump components. In contrastto literature studies, the research focuses on the development of analytical relationship between the valve plate geometrics and cavitations. The optimization method is applied to analyze the pressure undershoots compared with the saturated vapor pressure within the piston bore.The appropriate design of instantaneous flow areas between the valveplate and barrel kidney can be decided consequently.2 The Axial Piston Pump and Valve PlateThe typical schematic of the design of the axis piston pump is shown in Fig. 1. The shaft offset e is designed in this case to generate stroking containment moments for reducing cost purposes.The variation between the pivot center of the slipper and swash rotating center is shown as a. The swash angle αis the variable that determines the amount of fluid pumped per shaft revolution. In Fig. 1, the n th piston-slipper assembly is located at the angle ofθ. The displacement of the n thnpiston-slipper assembly along the x-axis can be written asx n= R tan(α)sin(θ)+ a sec(α)+ e tan(α) (1)nwhere R is the pitch radius of the rotating group.Then, the instantaneous velocity of the n th piston isx˙n = R 2sec ()αsin (n θ)α+ R tan (α)cos (n θ)ω+ R 2sec ()αsin (α)α + e 2sec ()αα (2)where the shaft rotating speed of the pump is ω=d n θ / dt .The valve plate is the most significant device to constraint flow inpiston pumps. The geometry of intake/discharge ports on the valve plateand its instantaneous relative positions with respect to barrel kidneys areusually referred to the valve plate timing. The ports of the valve plateoverlap with each barrel kidneys to construct a flow area or passage,which confines the fluid dynamics of the pump. In Fig. 2, the timingangles of the discharge and intake ports on the valve plate are listed as(,)T i d δ and (,)B i d δ. The opening angle of the barrel kidney is referred to asϕ. In some designs, there exists a simultaneous overlap between thebarrel kidney and intake/discharge slots at the locations of the top deadcenter (TDC) or bottom dead center (BDC) on the valve plate on whichthe overlap area appears together referred to as “cross -porting” in thepump design engineering. The cross-porting communicates the dischargeand intake ports, which may usually lower the volumetric efficiency. Thetrapped-volume design is compared with the design of the cross-porting,and it can achieve better efficiency 14]. However, the cross-porting isFig. 1 The typical axis piston pumpcommonly used to benefit the noise issue and pump stability in practice.3 The Control Volume of a Piston BoreIn the piston pump, the fluid within one piston is embraced by the piston bore, cylinder barrel, slipper, valve plate, and swash plate shown in Fig. 3. There exist some types of slip flow by virtue of relativeFig. 2 Timing of the valve platemotions and clearances between thos e components. Within the control volume of each piston bore, the instantaneous mass is calculated asM= n V(3)nwhere ρ and n V are the instantaneous density and volumesuch that themass time rate of change can be given asFig. 3 The control volume of the piston boren n n dM dV d V dt dt dtρρ=+ (4) where d n V is the varying of the volume.Based on the conservation equation, the mass rate in the control volume isn n dM q dtρ= (5)where n q is the instantaneous flow rate in and out of one piston. From the definition of the bulk modulus,n dP d dt dtρρβ= (6) where Pn is the instantaneous pressure within the piston bore. Substituting Eqs. (5) and (6) into Eq. (4) yields(?)n n n n n ndP q dV d V w d βθθ=- (7) where the shaft speed of the pump is n d dtθω=. The instantaneous volume of one piston bore can be calculated by using Eq. (1) asn V = 0V + P A [R tan (α)sin (n θ)+ a sec (α) + e tan(α) ] (8)where P A is the piston sectional area and 0V is the volume of eachpiston, which has zero displacement along the x-axis (when n θ=0, π).The volume rate of change can be calculated at the certain swash angle, i.e., α =0, such thattan cos n p n ndV A R d αθθ=()() (9) in which it is noted that the piston bore volume increases or decreaseswith respect to the rotating angle of n θ.Substituting Eqs. (8) and (9) into Eq. (7) yields0[tan()cos()] [tan sin sec tan() ]n P n n n p n q A R dP d V A R a e βαθωθαθαα-=-++()()()(10)4 Optimal DesignsTo find the extrema of pressure overshoots and undershoots in the control volume of piston bores, the optimization method can be used in Eq. (10). In a nonlinear function, reaching global maxima and minima is usually the goal of optimization. If the function is continuous on a closed interval, global maxima and minima exist. Furthermore, the global maximum (or minimum) either must be a local maximum (or minimum) in the interior of the domain or must lie on the boundary of the domain. So, the method of finding a global maximum (or minimum) is to detect all the local maxima (or minima) in the interior, evaluate the maxima (or minima) points on the boundary, and select the biggest (or smallest) one. Local maximum or local minimum can be searched by using the first derivative test that the potential extrema of a function f( · ), with derivative ()f ', can solve the equation at the critical points of ()f '=0 [15].The pressure of control volumes in the piston bore may be found as either a minimum or maximum value as dP/ dt=0. Thus, letting the left side of Eq. (10) be equal to zero yieldstan()cos()0n p n q A R ωαθ-= (11)In a piston bore, the quantity of n q offsets the volume varying and thendecreases the overshoots and undershoots of the piston pressure. In this study, the most interesting are undershoots of the pressure, which may fall below the vapor pressure or gas desorption pressure to cause cavitations. The term oftan()cos()p n A R ωαθ in Eq. (11) has the positive value in the range of intake ports (22ππθ-≤≤), shown in Fig. 2, which means that the piston volume arises. Therefore, the piston needs the sufficient flow in; otherwise, the pressure may drop.In the piston, the flow of n q may get through in a few scenariosshown in Fig. 3: (I) the clearance between the valve plate and cylinder barrel, (II) the clearance between the cylinder bore and piston, (III) the clearance between the piston and slipper, (IV) the clearance between the slipper and swash plate, and (V) the overlapping area between the barrel kidney and valve plate ports. As pumps operate stably, the flows in the as laminar flows, which can be calculated as [16]312IV k k Ln i I k h q p L ωμ==∑ (12)where k h is the height of the clearance, k L is the passage length,scenarios I –IV mostly have low Reynolds numbers and can be regarded k ω is the width of the clearance (note that in the scenario II, k ω =2π· r, in which r is the piston radius), and p is the pressure drop defined in the intake ports as p =c p -n p (13)where c p is the case pressure of the pump. The fluid films through theabove clearances were extensively investigated in previous research. The effects of the main related dimensions of pump and the operating conditions on the film are numerically clarified inRefs. [17,18]. The dynamic behavior of slipper pads and the clearance between the slipper and swash plate can be referred to Refs. [19,20]. Manring et al. [21,22] investigated the flow rate and load carrying capacity of the slipper bearing in theoretical and experimental methods under different deformation conditions. A simulation tool calledCASPAR is used to estimate the nonisothermal gap flow between the cylinder barrel and the valve plate by Huang and Ivantysynova [23]. The simulation program also considers the surface deformations to predict gap heights, frictions, etc., between the piston and barrel andbetween the swash plate and slipper. All these clearance geometrics in Eq.(12) are nonlinear and operation based, which is a complicated issue. In this study, the experimental measurements of the gap flows are preferred. If it is not possible, the worst cases of the geometrics or tolerances with empirical adjustments may be used to consider the cavitation issue, i.e., minimum gap flows.For scenario V, the flow is mostly in high velocity and can be described by using the turbulent orifice equation as((Tn d i d d q c A c A θθ= (14)where Pi and Pd are the intake and discharge pressure of the pump and ()i A θ and ()d A θ are the instantaneous overlap area between barrel kidneys and inlet/discharge ports of the valve plate individually.The areas are nonlinear functions of the rotating angle, which is defined by the geometrics of the barrel kidney, valve plate ports,silencing grooves, decompression holes, and so forth. Combining Eqs.(11) –(14), the area can be obtained as3()K IV A θ==(15)where ()A θ is the total overlap area of ()A θ=()()i d A A θλθ+, and λ is defined as=In the piston bore, the pressure varies from low tohigh while passing over the intake and discharge ports of the valve plates. It is possible that the instantaneous pressure achieves extremely low values during the intake area( 22ππθ-≤≤ shown in Fig. 2) that may be located below the vapor pressure vp p , i.e., n vp p p ≤;then cavitations canhappen. To prevent the phenomena, the total overlap area of ()A θ mightbe designed to be satisfied with30()K IV A θ=≥(16)where 0()A θ is the minimum area of 0()A θ=0()()i d A A θλθ+ and 0λis a constant that is0λ=gaseous form. The vapor pressure of any substance increases nonlinearly with temperature according to the Clausius –Clapeyron relation. With the incremental increase in temperature, the vapor pressure becomes sufficient to overcome particle attraction and make the liquid form bubbles inside the substance. For pure components, the vapor pressure can be determined by the temperature using the Antoine equation as /()10A B C T --, where T is the temperature, and A, B, and C are constants[24].As a piston traverse the intake port, the pressure varies dependent on the cosine function in Eq. (10). It is noted that there are some typical positions of the piston with respect to the intake port, the beginning and ending of overlap, i.e., TDC and BDC (/2,/2θππ=- ) and the zero displacement position (θ =0). The two situations will be discussed as follows:(1) When /2,/2θππ=-, it is not always necessary to maintain the overlap area of 0()A θ because slip flows may provide filling up for the vacuum. From Eq. (16), letting 0()A θ=0,the timing angles at the TDC and BDC may be designed as31cos ()tan()122IV c vpk k i I P k p p h A r L ωϕδωαμ--≤+∑ (17) in which the open angle of the barrel kidney is . There is nocross-porting flow with the timing in the intake port.(2) When θ =0, the function of cos θ has the maximum value, which can provide another limitation of the overlap area to prevent the low pressure undershoots suchthat 30(0)K IVA =≥ (18)where 0(0)A is the minimum overlap area of 0(0)(0)i A A =.To prevent the low piston pressure building bubbles, the vaporpressure is considered as the lower limitation for the pressure settings in Eq. (16). The overall of overlap areas then can be derived to have adesign limitation. The limitation is determined by the leakage conditions, vapor pressure, rotating speed, etc. It indicates that the higher the pumping speed, the more severe cavitation may happen, and then the designs need more overlap area to let flow in the piston bore. On the other side, the low vapor pressure of the hydraulic fluid is preferred to reduce the opportunities to reach the cavitation conditions. As a result, only the vapor pressure of the pure fluid is considered in Eqs. (16)–(18). In fact, air release starts in the higher pressure than the pure cavitation process mainly in turbulent shear layers, which occur in scenario V.Therefore, the vapor pressure might be adjusted to design the overlap area by Eq. (16) if there exists substantial trapped and dissolved air in the fluid.The laminar leakages through the clearances aforementioned are a tradeoff in the design. It is demonstrated that the more leakage from the pump case to piston may relieve cavitation problems.However, the more leakage may degrade the pump efficiency in the discharge ports. In some design cases, the maximum timing angles can be determined by Eq. (17)to not have both simultaneous overlapping and highly low pressure at the TDC and BDC.While the piston rotates to have the zero displacement, the minimum overlap area can be determined by Eq. 18 , which may assist the piston not to have the large pressure undershoots during flow intake.6 ConclusionsThe valve plate design is a critical issue in addressing the cavitation or aeration phenomena in the piston pump. This study uses the control volume method to analyze the flow, pressure, and leakages within one piston bore related to the valve plate timings. If the overlap area developed by barrel kidneys and valve plate ports is not properly designed, no sufficient flow replenishes the rise volume by the rotating movement. Therefore, the piston pressure may drop below the saturated vapor pressure of the liquid and air ingress to form the vapor bubbles. To control the damaging cavitations, the optimization approach is used to detect the lowest pressure constricted by valve plate timings. The analytical limitation of the overlap area needs to be satisfied to remain the pressure to not have large undershoots so that the system can be largely enhanced on cavitation/aeration issues.In this study, the dynamics of the piston control volume is developed by using several assumptions such as constant discharge coefficients and laminar leakages. The discharge coefficient is practically nonlinear based on the geometrics, flow number, etc. Leakage clearances of the control volume may not keep the constant height and width as well in practice due to vibrations and dynamical ripples. All these issues are complicated and very empirical and need further consideration in the future. Theresults presented in this paper can be more accurate in estimating the cavitations with these extensive studies.Nomenclature0(),()A A θθ= the total overlap area between valve plate ports and barrel kidneys 2()mmAp = piston section area 2()mmA, B, C= constantsA= offset between the piston-slipper joint and surface of the swash plate 2()mmd C = orifice discharge coefficiente= offset between the swash plate pivot and the shaft centerline of the pump 2()mmk h = the height of the clearance 2()mmk L = the passage length of the clearance 2()mmM= mass of the fluid within a single piston (kg)N= number of pistonsn = piston and slipper counter,p p = fluid pressure and pressure drop (bar)Pc= the case pressure of the pump (bar)Pd= pump discharge pressure (bar)Pi = pump intake pressure (bar)Pn = fluid pressure within the nth piston bore (bar)Pvp = the vapor pressure of the hydraulic fluid(bar)qn, qLn, qTn = the instantaneous flow rate of each piston(l/min)R = piston pitch radius 2()mmr = piston radius (mm)t =time (s)V = volume 3()mmwk = the width of the clearance (mm)x ,x ˙= piston displacement and velocity along the shaft axis (m, m/s) x y z --=Cartesian coordinates with an origin on the shaft centerline x y z '''--= Cartesian coordinates with an origin on swash plate pivot ,αα=swash plate angle and velocity (rad, rad/s)β= fluid bulk modulus (bar)δδ= timing angle of valve plates at the BDC and TDC (rad),B Tϕ= the open angle of the barrel kidney(rad)ρ= fluid density(kg/m3),θω= angular position and velocity of the rotating kit (rad, rad/s)μ=absolute viscosity(Cp),λλ= coefficients related to the pressure drop外文中文翻译:在轴向柱塞泵气蚀问题的分析本论文讨论和分析了一个柱塞孔与配流盘限制在轴向柱塞泵的控制量设计。

毕业设计英文 翻译(原文)

毕业设计英文 翻译(原文)

编号:毕业设计(论文)外文翻译(原文)院(系):桂林电子科技大学专业:电子信息工程学生姓名: xx学号: xxxxxxxxxxxxx 指导教师单位:桂林电子科技大学姓名: xxxx职称: xx2014年x月xx日Timing on and off power supplyusesThe switching power supply products are widely used in industrial automation and control, military equipment, scientific equipment, LED lighting, industrial equipment,communications equipment,electrical equipment,instrumentation, medical equipment, semiconductor cooling and heating, air purifiers, electronic refrigerator, LCD monitor, LED lighting, communications equipment, audio-visual products, security, computer chassis, digital products and equipment and other fields.IntroductionWith the rapid development of power electronics technology, power electronics equipment and people's work, the relationship of life become increasingly close, and electronic equipment without reliable power, into the 1980s, computer power and the full realization of the switching power supply, the first to complete the computer Power new generation to enter the switching power supply in the 1990s have entered into a variety of electronic, electrical devices, program-controlled switchboards, communications, electronic testing equipment power control equipment, power supply, etc. have been widely used in switching power supply, but also to promote the rapid development of the switching power supply technology .Switching power supply is the use of modern power electronics technology to control the ratio of the switching transistor to turn on and off to maintain a stable output voltage power supply, switching power supply is generally controlled by pulse width modulation (PWM) ICs and switching devices (MOSFET, BJT) composition. Switching power supply and linear power compared to both the cost and growth with the increase of output power, but the two different growth rates. A power point, linear power supply costs, but higher than the switching power supply. With the development of power electronics technology and innovation, making the switching power supply technology to continue to innovate, the turning points of this cost is increasingly move to the low output power side, the switching power supply provides a broad space for development.The direction of its development is the high-frequency switching power supply, high frequency switching power supply miniaturization, and switching power supply into a wider range of application areas, especially in high-tech fields, and promote the miniaturization of high-tech products, light of. In addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental protection are of great significance.classificationModern switching power supply, there are two: one is the DC switching power supply; the other is the AC switching power supply. Introduces only DC switching power supply and its function is poor power quality of the original eco-power (coarse) - such as mains power or battery power, converted to meet the equipment requirements of high-quality DC voltage (Varitronix) . The core of the DC switching power supply DC / DC converter. DC switching power supply classification is dependent on the classification of DC / DC converter. In other words, the classification of the classification of the DC switching power supply and DC/DC converter is the classification of essentially the same, the DC / DC converter is basically a classification of the DC switching power supply.DC /DC converter between the input and output electrical isolation can be divided into two categories: one is isolated called isolated DC/DC converter; the other is not isolated as non-isolated DC / DC converter.Isolated DC / DC converter can also be classified by the number of active power devices. The single tube of DC / DC converter Forward (Forward), Feedback (Feedback) two. The double-barreled double-barreled DC/ DC converter Forward (Double Transistor Forward Converter), twin-tube feedback (Double Transistor Feedback Converter), Push-Pull (Push the Pull Converter) and half-bridge (Half-Bridge Converter) four. Four DC / DC converter is the full-bridge DC / DC converter (Full-Bridge Converter).Non-isolated DC / DC converter, according to the number of active power devices can be divided into single-tube, double pipe, and four three categories. Single tube to a total of six of the DC / DC converter, step-down (Buck) DC / DC converter, step-up (Boost) DC / DC converters, DC / DC converter, boost buck (Buck Boost) device of Cuk the DC / DC converter, the Zeta DC / DC converter and SEPIC, the DC / DC converter. DC / DC converters, the Buck and Boost type DC / DC converter is the basic buck-boost of Cuk, Zeta, SEPIC, type DC / DC converter is derived from a single tube in this six. The twin-tube cascaded double-barreled boost (buck-boost) DC / DC converter DC / DC converter. Four DC / DC converter is used, the full-bridge DC / DC converter (Full-Bridge Converter).Isolated DC / DC converter input and output electrical isolation is usually transformer to achieve the function of the transformer has a transformer, so conducive to the expansion of the converter output range of applications, but also easy to achieve different voltage output , or a variety of the same voltage output.Power switch voltage and current rating, the converter's output power is usually proportional to the number of switch. The more the number of switch, the greater the output power of the DC / DC converter, four type than the two output power is twice as large,single-tube output power of only four 1/4.A combination of non-isolated converters and isolated converters can be a single converter does not have their own characteristics. Energy transmission points, one-way transmission and two-way transmission of two DC / DC converter. DC / DC converter with bi-directional transmission function, either side of the transmission power from the power of lateral load power from the load-lateral side of the transmission power.DC / DC converter can be divided into self-excited and separately controlled. With the positive feedback signal converter to switch to self-sustaining periodic switching converter, called self-excited converter, such as the the Luo Yeer (Royer,) converter is a typical push-pull self-oscillating converter. Controlled DC / DC converter switching device control signal is generated by specialized external control circuit.the switching power supply.People in the field of switching power supply technology side of the development of power electronic devices, while the development of the switching inverter technology, the two promote each other to promote the switching power supply annual growth rate of more than two digits toward the light, small, thin, low-noise, high reliability, the direction of development of anti-jamming. Switching power supply can be divided into AC / DC and DC / DC two categories, AC / AC DC / AC, such as inverters, DC / DC converter is now modular design technology and production processes at home and abroad have already matured and standardization, and has been recognized by the user, but AC / DC modular, its own characteristics make the modular process, encounter more complex technology and manufacturing process. Hereinafter to illustrate the structure and characteristics of the two types of switching power supply.Self-excited: no external signal source can be self-oscillation, completely self-excited to see it as feedback oscillation circuit of a transformer.Separate excitation: entirely dependent on external sustain oscillations, excited used widely in practical applications. According to the excitation signal structure classification; can be divided into pulse-width-modulated and pulse amplitude modulated two pulse width modulated control the width of the signal is frequency, pulse amplitude modulation control signal amplitude between the same effect are the oscillation frequency to maintain within a certain range to achieve the effect of voltage stability. The winding of the transformer can generally be divided into three types, one group is involved in the oscillation of the primary winding, a group of sustained oscillations in the feedback winding, there is a group of load winding. Such as Shanghai is used in household appliances art technological production of switching power supply, 220V AC bridge rectifier, changing to about 300V DC filter added tothe collector of the switch into the transformer for high frequency oscillation, the feedback winding feedback to the base to maintain the circuit oscillating load winding induction signal, the DC voltage by the rectifier, filter, regulator to provide power to the load. Load winding to provide power at the same time, take up the ability to voltage stability, the principle is the voltage output circuit connected to a voltage sampling device to monitor the output voltage changes, and timely feedback to the oscillator circuit to adjust the oscillation frequency, so as to achieve stable voltage purposes, in order to avoid the interference of the circuit, the feedback voltage back to the oscillator circuit with optocoupler isolation.technology developmentsThe high-frequency switching power supply is the direction of its development, high-frequency switching power supply miniaturization, and switching power supply into the broader field of application, especially in high-tech fields, and promote the development and advancement of the switching power supply, an annual more than two-digit growth rate toward the light, small, thin, low noise, high reliability, the direction of the anti-jamming. Switching power supply can be divided into AC / DC and DC / DC two categories, the DC / DC converter is now modular design technology and production processes at home and abroad have already matured and standardized, and has been recognized by the user, but modular AC / DC, because of its own characteristics makes the modular process, encounter more complex technology and manufacturing process. In addition, the development and application of the switching power supply in terms of energy conservation, resource conservation and environmental protection are of great significance.The switching power supply applications in power electronic devices as diodes, IGBT and MOSFET.SCR switching power supply input rectifier circuit and soft start circuit, a small amount of applications, the GTR drive difficult, low switching frequency, gradually replace the IGBT and MOSFET.Direction of development of the switching power supply is a high-frequency, high reliability, low power, low noise, jamming and modular. Small, thin, and the key technology is the high frequency switching power supply light, so foreign major switching power supply manufacturers have committed to synchronize the development of new intelligent components, in particular, is to improve the secondary rectifier loss, and the power of iron Oxygen materials to increase scientific and technological innovation in order to improve the magnetic properties of high frequency and large magnetic flux density (Bs), and capacitor miniaturization is a key technology. SMT technology allows the switching power supply has made considerable progress, the arrangement of the components in the circuit board on bothsides, to ensure that the light of the switching power supply, a small, thin. High-frequency switching power supply is bound to the traditional PWM switching technology innovation, realization of ZVS, ZCS soft-switching technology has become the mainstream technology of the switching power supply, and a substantial increase in the efficiency of the switching power supply. Indicators for high reliability, switching power supply manufacturers in the United States by reducing the operating current, reducing the junction temperature and other measures to reduce the stress of the device, greatly improve the reliability of products.Modularity is the overall trend of switching power supply, distributed power systems can be composed of modular power supply, can be designed to N +1 redundant power system, and the parallel capacity expansion. For this shortcoming of the switching power supply running noise, separate the pursuit of high frequency noise will also increase, while the use of part of the resonant converter circuit technology to achieve high frequency, in theory, but also reduce noise, but some The practical application of the resonant converter technology, there are still technical problems, it is still a lot of work in this field, so that the technology to be practical.Power electronics technology innovation, switching power supply industry has broad prospects for development. To accelerate the pace of development of the switching power supply industry in China, it must take the road of technological innovation, out of joint production and research development path with Chinese characteristics and contribute to the rapid development of China's national economy.Developments and trends of the switching power supply1955 U.S. Royer (Roger) invented the self-oscillating push-pull transistor single-transformer DC-DC converter is the beginning of the high-frequency conversion control circuit 1957 check race Jen, Sen, invented a self-oscillating push-pull dual transformers, 1964, U.S. scientists canceled frequency transformer in series the idea of switching power supply, the power supply to the size and weight of the decline in a fundamental way. 1969 increased due to the pressure of the high-power silicon transistor, diode reverse recovery time shortened and other components to improve, and finally made a 25-kHz switching power supply.At present, the switching power supply to the small, lightweight and high efficiency characteristics are widely used in a variety of computer-oriented terminal equipment, communications equipment, etc. Almost all electronic equipment is indispensable for a rapid development of today's electronic information industry power mode. Bipolar transistor made of 100kHz, 500kHz power MOS-FET made, though already the practical switching power supply is currently available on the market, but its frequency to be further improved. Toimprove the switching frequency, it is necessary to reduce the switching losses, and to reduce the switching losses, the need for high-speed switch components. However, the switching speed will be affected by the distribution of the charge stored in the inductance and capacitance, or diode circuit to produce a surge or noise. This will not only affect the surrounding electronic equipment, but also greatly reduce the reliability of the power supply itself. Which, in order to prevent the switching Kai - closed the voltage surge, RC or LC buffers can be used, and the current surge can be caused by the diode stored charge of amorphous and other core made of magnetic buffer . However, the high frequency more than 1MHz, the resonant circuit to make the switch on the voltage or current through the switch was a sine wave, which can reduce switching losses, but also to control the occurrence of surges. This switch is called the resonant switch. Of this switching power supply is active, you can, in theory, because in this way do not need to greatly improve the switching speed of the switching losses reduced to zero, and the noise is expected to become one of the high-frequency switching power supply The main ways. At present, many countries in the world are committed to several trillion Hz converter utility.the principle of IntroductionThe switching power supply of the process is quite easy to understand, linear power supplies, power transistors operating in the linear mode and linear power, the PWM switching power supply to the power transistor turns on and off state, in both states, on the power transistor V - security product is very small (conduction, low voltage, large current; shutdown, voltage, current) V oltammetric product / power device is power semiconductor devices on the loss.Compared with the linear power supply, the PWM switching power supply more efficient process is achieved by "chopping", that is cut into the amplitude of the input DC voltage equal to the input voltage amplitude of the pulse voltage. The pulse duty cycle is adjusted by the switching power supply controller. Once the input voltage is cut into the AC square wave, its amplitude through the transformer to raise or lower. Number of groups of output voltage can be increased by increasing the number of primary and secondary windings of the transformer. After the last AC waveform after the rectifier filter the DC output voltage.The main purpose of the controller is to maintain the stability of the output voltage, the course of their work is very similar to the linear form of the controller. That is the function blocks of the controller, the voltage reference and error amplifier can be designed the same as the linear regulator. Their difference lies in the error amplifier output (error voltage) in the drive before the power tube to go through a voltage / pulse-width conversion unit.Switching power supply There are two main ways of working: Forward transformand boost transformation. Although they are all part of the layout difference is small, but the course of their work vary greatly, have advantages in specific applications.the circuit schematicThe so-called switching power supply, as the name implies, is a door, a door power through a closed power to stop by, then what is the door, the switching power supply using SCR, some switch, these two component performance is similar, are relying on the base switch control pole (SCR), coupled with the pulse signal to complete the on and off, the pulse signal is half attentive to control the pole voltage increases, the switch or transistor conduction, the filter output voltage of 300V, 220V rectifier conduction, transmitted through the switching transformer secondary through the transformer to the voltage increase or decrease for each circuit work. Oscillation pulse of negative semi-attentive to the power regulator, base, or SCR control voltage lower than the original set voltage power regulator cut-off, 300V power is off, switch the transformer secondary no voltage, then each circuit The required operating voltage, depends on this secondary road rectifier filter capacitor discharge to maintain. Repeat the process until the next pulse cycle is a half weeks when the signal arrival. This switch transformer is called the high-frequency transformer, because the operating frequency is higher than the 50HZ low frequency. Then promote the pulse of the switch or SCR, which requires the oscillator circuit, we know, the transistor has a characteristic, is the base-emitter voltage is 0.65-0.7V is the zoom state, 0.7V These are the saturated hydraulic conductivity state-0.1V-0.3V in the oscillatory state, then the operating point after a good tune, to rely on the deep negative feedback to generate a negative pressure, so that the oscillating tube onset, the frequency of the oscillating tube capacitor charging and discharging of the length of time from the base to determine the oscillation frequency of the output pulse amplitude, and vice versa on the small, which determines the size of the output voltage of the power regulator. Transformer secondary output voltage regulator, usually switching transformer, single around a set of coils, the voltage at its upper end, as the reference voltage after the rectifier filter, then through the optocoupler, this benchmark voltage return to the base of the oscillating tube pole to adjust the level of the oscillation frequency, if the transformer secondary voltage is increased, the sampling coil output voltage increases, the positive feedback voltage obtained through the optocoupler is also increased, this voltage is applied oscillating tube base, so that oscillation frequency is reduced, played a stable secondary output voltage stability, too small do not have to go into detail, nor it is necessary to understand the fine, such a high-power voltage transformer by switching transmission, separated and after the class returned by sampling the voltage from the opto-coupler pass separated after class, so before the mains voltage, and after the classseparation, which is called cold plate, it is safe, transformers before power is independent, which is called switching power supply.the DC / DC conversionDC / DC converter is a fixed DC voltage transformation into a variable DC voltage, also known as the DC chopper. There are two ways of working chopper, one Ts constant pulse width modulation mode, change the ton (General), the second is the frequency modulation, the same ton to change the Ts, (easy to produce interference). Circuit by the following categories:Buck circuit - the step-down chopper, the average output voltage U0 is less than the input voltage Ui, the same polarity.Boost Circuit - step-up chopper, the average output voltage switching power supply schematic U0 is greater than the input voltage Ui, the same polarity.Buck-Boost circuit - buck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, the inductance transmission.Cuk circuit - a buck or boost chopper, the output average voltage U0 is greater than or less than the input voltage Ui, the opposite polarity, capacitance transmission.The above-mentioned non-isolated circuit, the isolation circuit forward circuits, feedback circuit, the half-bridge circuit, the full bridge circuit, push-pull circuit. Today's soft-switching technology makes a qualitative leap in the DC / DC the U.S. VICOR company design and manufacture a variety of ECI soft-switching DC / DC converter, the maximum output power 300W, 600W, 800W, etc., the corresponding power density (6.2 , 10,17) W/cm3 efficiency (80-90)%. A the Japanese Nemic Lambda latest using soft-switching technology, high frequency switching power supply module RM Series, its switching frequency (200 to 300) kHz, power density has reached 27W/cm3 with synchronous rectifier (MOSFETs instead of Schottky diodes ), so that the whole circuit efficiency by up to 90%.AC / DC conversionAC / DC conversion will transform AC to DC, the power flow can be bi-directional power flow by the power flow to load known as the "rectification", referred to as "active inverter power flow returned by the load power. AC / DC converter input 50/60Hz AC due must be rectified, filtered, so the volume is relatively large filter capacitor is essential, while experiencing safety standards (such as UL, CCEE, etc.) and EMC Directive restrictions (such as IEC, FCC, CSA) in the AC input side must be added to the EMC filter and use meets the safety standards of the components, thus limiting the miniaturization of the volume of AC / DC power, In addition, due to internal frequency, high voltage, current switching, making the problem difficult to solve EMC also high demands on the internal high-density mountingcircuit design, for the same reason, the high voltage, high current switch makes power supply loss increases, limiting the AC / DC converter modular process, and therefore must be used to power system optimal design method to make it work efficiency to reach a certain level of satisfaction.AC / DC conversion circuit wiring can be divided into half-wave circuit, full-wave circuit. Press the power phase can be divided into single-phase three-phase, multiphase. Can be divided into a quadrant, two quadrant, three quadrants, four-quadrant circuit work quadrant.he selection of the switching power supplySwitching power supply input on the anti-jamming performance, compared to its circuit structure characteristics (multi-level series), the input disturbances, such as surge voltage is difficult to pass on the stability of the output voltage of the technical indicators and linear power have greater advantages, the output voltage stability up to (0.5)%. Switching power supply module as an integrated power electronic devices should be selected。

本科毕业设计(论文)英文翻译模板

本科毕业设计(论文)英文翻译模板

本科毕业设计(论文)英文翻译论文标题(中文)学院******姓名***专业*******班级**********大气探测2班学号*************** 大气探测、信处、两个专业填写电子信息工程。

生物医学工程、电子信息科学与技术、雷电防护科学与技术As its name implies, region growing is a procedure that groups pixels or subregions into larger regions based on predefined criteria. The basic approach is to start with a set of “seed ” points and from these grow regions by appending to each seed those gray level or color).be used to assignpixels to regions during the centroid of these clusters can be used as seeds.… … …左右手共面波导的建模与带通滤波器设计速发展之势,而它的出现却是源于上世纪本研究提出了一种新型混合左右手(CPW )的独特功能。

目前这种有效电长度为0°的新型混合左右手共面波导(CRLH CPW )谐振器正在兴起,这种谐振器工作在5GHz 时的体积比常规结构的谐振器缩减小49.1%。

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毕业设计英文资料翻译Translation of the English Documents for Graduation Design课题名称院(系)专业姓名学号起讫日期指导教师2011 年 02 月 20 日译文:室内设计室内设计不仅包括装修及家具的空间,而且还考虑到空间规划,灯光,与用户行为有关的程序化问题,包括从具体问题的可及性到在空间中的活动的性质。

在商业和公共空间显著的变化后,室内设计如今的标志是一个新的弹性类型学。

室内设计不仅包括方案规划也包括室内空间的物理治疗:预测其使用的性质以及它的家具和表面,包括墙,地面,天花板。

在职权范围上,室内设计有别于室内装修工程。

装修关心的是家具的选择,然而设计者要把离散的装饰元素整合成方案关注的空间和使用。

室内设计师在从底层向上的内部的空间时间方面与与建筑师合作,但是他们仍然独立的工作,尤其在翻修的情况下。

历史上,植根于总体艺术作品的概念,曾经都是建筑师设计的。

总体艺术作品的概念源于十九世纪末和二十世纪初的工艺美术运动。

其支持者(从弗兰克·劳埃德·赖特到凡德罗)在室内设计专业的起源期间延长其做法以包括内饰领域行为并不是偶然的。

事实上,这是一个建筑师采取的防御措施,建筑师们把室内装修或设计师的形式上的干预看作是对他们完整的艺术性的一种威胁。

如今,除了像理查德·迈耶那样的非常重视均匀性的现代主义者,扮演室内设计师角色的建筑师(数量在增长)更有倾向于理论与实践的折衷,并联21世纪的定价多元化。

尽管如此,对室内设计师以及室内设计领域的偏见持续存在。

由于室内被视为一个集装箱的蜉蝣,从而阻碍了对室内的批评性的讨论。

此外,对室内的传统观点充满了偏见:阶级偏见与百年历史的协会商人有关,性别偏见与把装饰行业描述成主要是妇女和男性同性恋的领域。

因此,室内设计作为文化价值的表达的信誉已被严重损坏。

然而,对文化大系统的理解在全球化的影响下一直在变化。

在一个更宽容的环境中,鼓励不同文化间的融合,高文化和低文化的区别被消除。

同样,有更频繁的生产性借贷的事例发生在建筑,设计,装修等曾经被看作是专有领地的领域。

并且建筑,室内设计,室内装修领域仍然有不同的教育协议以及不同的关注重点,他们表现出更大的互相的兴趣。

另一种考虑这种新兴的合成的方法是用现代,技术和历史替代建筑,室内设计和装修的三合一。

后现代时代的特征之一是提高了对过去影响现在的角色的认识。

在室内,这表现在一个新的兴趣饰品,工艺和重要性以及空间复杂性,所有平行于正在运行的现代化的项目。

更重要的是,有一种新的弹性类型学。

如今,传统的室内类型例如房子,仓库,办公室,餐厅等,尽力控制它们的边界。

方案收敛的表现能在公共场合以及商业空间被清晰的发现,渴望更加界面友好和有消费意识。

越来越多的私立医院(竞争患者)雇用设施并形成灵感来自豪华温泉的语言;同时,许多体育馆以及健身俱乐部采用临床医疗设施以向客户介绍自己服务的价值。

同样的室内协议能够在办公室中发现,指派非正式的,现场工作理论的艺术家的仓库。

在旅馆使用美术馆的语言。

相似的,越来越多的杂货店和书店包括用于饮食和交际的空间以及家具。

同时,有一种新的舒适的在室内风格上趋同,从设计的历史上私有和重组不同的报价。

这些室内布局是艺术的混合,它们不是简单的混合以及匹配家具和风格,而是通过当代的镜头进行过滤。

现代室内布局的另一个标志是叙事的公开结合。

在零售空间坚持严格的环境主题,例如拉尔夫·劳伦服装店和像拉斯维加斯的赌场那样的娱乐场所。

然而,更好玩的小线性办法说明越来越普遍。

在所有的室内类型学中,住宅已经被改变所轻微的影响,除了短暂的趋势,如室外厨房和浴室的魅力。

然而,住宅设计占据室内设计全面的主导地位。

它已经成为反思的催化剂,使得一系列空间坚定的从中分离出来,从秘书室到护士站再到图书馆的阅览室。

办公室的个人住宿的考虑,医院色彩的使用,图书馆提供沙发正变的很平常,仅仅引用这三个例子。

这种环境(与窗帘,壁纸,除其他住宅要素)为以前的地域提供了更多的舒适性,安心,愉悦,而这是以前惯例所禁止和社会所排除的。

毫无疑问的,这些公共领域以及商业空间的变化是由20世纪60年代的解放运动带来的。

这些运动反对种族,阶级,性别的障碍,以及作为更大气候以及好客和住宿基础的身体能力。

在流行的住宅模式中发现一个完全不同的议程也是可能的。

把国内设施投入到商业空间,例如办公室室内的娱乐空间也可以解释为一个更广泛的尝试的一部分,尝试把更容易既接受的氛围引入自由资本主义市场。

从这点上来看,室内设计肩负着娱乐的任务,没有什么新的把戏。

每一个室内布局都是舞台设置的基础。

它也不是特别隐匿-只要自负是透明的。

然而,当幻想变成妄想,也就是当为疾病的现实而设计补偿过度时,或者当由于全天候经济的无情的要求使得办公室变成代理人的公寓时,这是危险的表现。

在这些情况下,设计放弃其潜力改变日常生活,金额略多于一个浅显的重新命名空间。

另外一种力量正在推动室内设计的演化,扩大公众对设计以及设计师的认识。

设计作为市容和地位的象征的需求在逐渐增长,受住房杂志扩散的影响,电视节目专门讨论家庭装饰以及广告系列的商业实体,例如塔吉特和宜家家居。

在西方,繁荣再加上媒体的胃口,已经全部迷恋室内设计,也反映了自恋的消费推动型社会。

一方面,越来越多的公众形象设计产生出的有正面的民主的成果,这些设计能够在DIY网络站点上看到,并且像家庭百货那样的企业强调自力更生。

这也可以更普遍的认为重新审议美中隐含的定价设计是一种社会现象,由其倾向去激励情况有所改善。

另一方面,室内设计的通过人物例如菲利普斯塔克,玛莎斯图尔特和芭芭拉巴里的流行已经鼓励肤浅理解内部的注意力更多地集中在物体而不是对行为和相互作用的对象。

在室内设计方面,所有最近的爆炸事件,仍然存在根本的保守的舞台设计,因为它是根深蒂固的安全性与舒适性的观念中。

这种看法由于特殊行动而加剧了,例如,医疗和盛情款待。

虽然这些企业了深入了解心理学,力学和经济学知识的特殊环境,但是它们还长期区别阻碍更有机结合的办法,内部的延伸架构,甚至外面的风景。

一个显著的例外是设计和建筑公司的增加,增加了的支撑材料以及其在室内应用方面的专门的技术。

同时,设计公司用持久性标识自己,并提升自己为环保主义者。

一场用行动承担环境责任的活动正在开展。

在过去的四十年间,人们努力使室内设计领域专业化并给予它与建筑平等的地位。

在美国和加拿大,室内教育学会以前叫做教育研究基金会,讨论在学院以及大学里的室内设计教育以形成实践的标准。

此外,国际工业设计会议把室内设计包含在其范围内,把它定义为是“智力性的专业,而非仅仅是交易或者一种娱乐服务”的一部分。

然而,室内设计人员的教育仍然随着无标准教育而存在惊人的变数。

因此,室内设计仍然被认为是对专家和业余人员都开放的领域。

这种观念的形成和这个领域较短的历史以及更广阔的文化外力相互包含相互作用导致的全球化有关。

原文:Interior DesignSusan YelavichInterior design embraces not only the decoration and furnishing of space, but also considerations of space planning, lighting, and programmatic issues pertaining to user behaviors, ranging from specific issues of accessibility to the nature of the activities to be conducted in the space. The hallmark of interior design today is a new elasticity in typologies, seen most dramatically in the domestication of commercial and public spaces.Interior design encompasses both the programmatic planning and physical treatment of interior space: the projection of its use and the nature of its furnishings and surfaces, that is, walls, floors, and ceilings. Interior design is distinguished from interior decoration in the scope of its purview. Decorators are primarily concerned with the selection of furnishings, while designers integrate the discrete elements of décor into programmatic concerns of space and use. Interior designers generally practice collaboratively with architects on the interiors of spaces built from the ground up, but they also work independently, particularly in the case of renovations. There is also a strong history of architect-designed interiors, rooted in the concept of Gesamtkunstwerk, the total work of art, that came out of the Arts & Crafts movement of the late nineteenth and early twentieth century. It is no accident that its strongest proponents (from Frank Lloyd Wright to Mies van der Rohe) extended their practices to include the realm of interiors during the nascency of the interior-design profession. Indeed, it was a defensive measure taken by architects who viewed formal intervention by an interior decorator or designer as a threat to the integrity of their aesthetic.Today, apart from strict modernists like Richard Meier who place a premium on homogeneity, architects who take on the role of interior designer (and their numbers are growing) are more likely to be eclectic in philosophy and practice, paralleling the twenty-firstcentury's valorization of plurality. Nonetheless, the bias against interior designers and the realm of the interior itself continues to persist. Critical discussions of the interior have been hampered by its popular perception as a container of ephemera. Furthermore, conventional views of the interior have been fraught with biases: class biases related to centuries-old associations with tradesmen and gender biases related to the depiction of the decorating profession as primarily the domain of women and gay men. As a result, the credibility of the interior as an expressionof cultural values has been seriously impaired.However, the conditions and the light in which culture-at-large is understood are changing under the impact of globalization. The distinctions between “high” culture and “low” culture are dissipating in a more tolerant climate that encourages the cross-fertilization between the two poles. Likewise, there are more frequent instances of productive borrowings among architecture, design, and decoration, once considered exclusive domains. And while the fields of architecture, interior design, and interior decoration still have different educational protocols and different concentrations of emphasis, they are showing a greater mutuality of interest.Another way to think of this emergent synthesis is to substitute the triad of “architecture, interior design, and decoration” with “modernity, technology, and history.” One of the hallmarks of the postmodern era is a heightened awareness of the role of the past in shaping the present. In the interior, this manifests itself in a renewed interest in ornament, in evidence of craft and materiality, and in spatial complexities, all running parallel to the ongoing project of modernity.Even more significantly, there is a new elasticity in typologies. Today, the traditional typologies of the interior—house, loft, office, restaurant, and so on—strain to control their borders. Evidence of programmatic convergences can clearly be seen in public and commercial spaces that aspire to be both more user-friendly and consumer-conscious. Growing numbers of private hospitals (in competition for patients) employ amenities and form languages inspired by luxury spas; at the same time, many gyms and health clubs are adopting the clinical mien of medical facilities to convince their clients of the value of their services. The same relaxation of interior protocols can be seen in offices that co-opt the informal, live-work ethic of the artist's loft, and in hotels that use the language (and contents) of galleries. Similarly, increasing numbers of grocery stores and bookstores include spaces and furniture for eating andsocializing.Likewise, there is a new comfort with stylistic convergences in interiors that appropriate and recombine disparate quotations from design history. These are exemplified in spaces such as Rem Koolhaas' Casa da Musica (2005) in Porto, Portugal (with its inventive use of traditional Portuguese tiles), and Herzog & de Meuron's Walker Art Center (2005) in Minneapolis, Minnesota (where stylized acanthus-leaf patterns are used to mark gallery entrances). These interiors make an art out of hybridism. They do not simply mix and match period furnishings and styles, but refilter them through a contemporary lens.Another hallmark of the contemporary interior is the overt incorporation of narrative. Tightly themed environments persist in retail spaces such as Ralph Lauren's clothing stores and in entertainment spaces like Las Vegas casinos. However, a more playful and less linear approach to narrative is increasingly common.Of all the typologies of the interior, the residence has been least affected by change, apart from ephemeral trends such as outdoor kitchens and palatial bathrooms. However, the narrative of the residence dominates interior design at large. It has become the catalyst for rethinking a host of spaces once firmly isolated from it, ranging from the secretary's cubicle, to the nurse's station, to the librarian's reading room. Considerations such as the accommodation of personal accessories in the work space, the use of color in hospitals, and the provision of couches in libraries are increasingly common, to cite just three examples. The domestication of such environments (with curtains and wallpaper, among other residential elements) provides more comfort, more reassurance, and more pleasure to domains formerly defined by institutional prohibitions and social exclusions. Unquestionably, these changes in public and commercial spaces are indebted to the liberation movements of the late 1960s. The battles fought against barriers of race, class, gender, and physical ability laid the groundwork for a larger climate of hospitality and accommodation.It is also possible to detect a wholly other agenda in the popularity of the residential model. The introduction of domestic amenities into commercial spaces, such as recreation spaces in office interiors, can also be construed as part of a wider attempt to put a more acceptable face on the workings of free-market capitalism. In this view, interior design dons the mask of entertainment. There is nothing new about the charade. Every interior is fundamentally a stageset. Nor is it particularly insidious—as long as the conceit is transparent. Danger surfaces, however, when illusion becomes delusion—when design overcompensates for the realities of illness with patronizing sentiment, or when offices become surrogate apartments because of the relentless demands of a round-the-clock economy. In these instances, design relinquishes its potential to transform daily life in favor of what amounts to little more than a facile re-branding of space.Another force is driving the domestication of the interior and that is the enlarged public awareness of design and designers. There is a growing popular demand for design as amenity and status symbol, stimulated by the proliferation of shelter magazines, television shows devoted to home decorating, and the advertising campaigns of commercial entities such as Target and Ikea. In the Western world, prosperity, combined with the appetite of the media, has all but fetishized the interior, yielding yet another reflection of the narcissism of aconsumer-driven society. On the one hand, there are positive, democratic outcomes of the growing public profile of design that can be seen in the rise of do-it-yourself web sites and enterprises like Home Depot that emphasize self-reliance. It can also be argued, more generally, that the reconsideration of beauty implicit in the valorization of design is an ameliorating social phenomenon by virtue of its propensity to inspire improvement. On the other hand, the popularization of interior design through personas such as Philippe Starck, Martha Stewart, and Barbara Barry has encouraged a superficial understanding of the interior that is more focused on objects than it is on behaviors and interactions among objects.For all the recent explosion of interest in interior design, it remains, however, a fundamentally conservative arena of design, rooted as it is in notions of enclosure, security, and comfort. This perception has been exacerbated by the growth of specialized practices focused, for example, on healthcare and hospitality. While such firms offer deep knowledge of the psychology, mechanics, and economies of particular environments, they also perpetuate distinctions that hinder a more integral approach to the interior as an extension of architecture and even the landscape outside. One notable exception is the growth of design and architecture firms accruing expertise in sustainable materials and their applications to the interior. At the same time that design firms are identifying themselves with sustainability and promoting themselves as environmentalists, a movement is building to incorporate environmentalresponsibility within normative practice.Over the past four decades, efforts have intensified to professionalize the field of interior design and to accord it a status equal to that of architecture. In the US and Canada the Council for Interior Design Accreditation, formerly known as FIDER, reviews interior design education programs at colleges and universities to regulate standards of practice. Furthermore, the International Council of Societies of Industrial Design (ICSID) embraces interior design within its purview, defining it as part of “intelle ctual profession, and not simply a trade or a service for enterprises.”Yet, the education of interior designers remains tremendously variable, with no uniformity of pedagogy. Hence, interior design continues to be perceived as an arena open to the specialist and the amateur. This perception is indicative of both the relatively short history of the profession itself and the broader cultural forces of inclusion and interactivity that mark a global society.原文来源:Board of International Research in Design,Design Dictionary Perspectives on Design Terminology,Birkhäuser V erlag AG 2008。

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