毕业设计(论文)外文文献译文
本科毕业论文外文翻译【范本模板】
本科毕业论文外文翻译外文译文题目:不确定条件下生产线平衡:鲁棒优化模型和最优解解法学院:机械自动化专业:工业工程学号: 201003166045学生姓名: 宋倩指导教师:潘莉日期: 二○一四年五月Assembly line balancing under uncertainty: Robust optimization modelsand exact solution methodÖncü Hazır , Alexandre DolguiComputers &Industrial Engineering,2013,65:261–267不确定条件下生产线平衡:鲁棒优化模型和最优解解法安库·汉泽,亚历山大·多桂计算机与工业工程,2013,65:261–267摘要这项研究涉及在不确定条件下的生产线平衡,并提出两个鲁棒优化模型。
假设了不确定性区间运行的时间。
该方法提出了生成线设计方法,使其免受混乱的破坏。
基于分解的算法开发出来并与增强策略结合起来解决大规模优化实例.该算法的效率已被测试,实验结果也已经发表。
本文的理论贡献在于文中提出的模型和基于分解的精确算法的开发.另外,基于我们的算法设计出的基于不确定性整合的生产线的产出率会更高,因此也更具有实际意义。
此外,这是一个在装配线平衡问题上的开创性工作,并应该作为一个决策支持系统的基础。
关键字:装配线平衡;不确定性; 鲁棒优化;组合优化;精确算法1.简介装配线就是包括一系列在车间中进行连续操作的生产系统。
零部件依次向下移动直到完工。
它们通常被使用在高效地生产大量地标准件的工业行业之中。
在这方面,建模和解决生产线平衡问题也鉴于工业对于效率的追求变得日益重要。
生产线平衡处理的是分配作业到工作站来优化一些预定义的目标函数。
那些定义操作顺序的优先关系都是要被考虑的,同时也要对能力或基于成本的目标函数进行优化。
就生产(绍尔,1999)产品型号的数量来说,装配线可分为三类:单一模型(SALBP),混合模型(MALBP)和多模式(MMALBP)。
毕业论文(设计)外文文献翻译及原文
金融体制、融资约束与投资——来自OECD的实证分析R.SemenovDepartment of Economics,University of Nijmegen,Nijmegen(荷兰内梅亨大学,经济学院)这篇论文考查了OECD的11个国家中现金流量对企业投资的影响.我们发现不同国家之间投资对企业内部可获取资金的敏感性具有显著差异,并且银企之间具有明显的紧密关系的国家的敏感性比银企之间具有公平关系的国家的低.同时,我们发现融资约束与整体金融发展指标不存在关系.我们的结论与资本市场信息和激励问题对企业投资具有重要作用这种观点一致,并且紧密的银企关系会减少这些问题从而增加企业获取外部融资的渠道。
一、引言各个国家的企业在显著不同的金融体制下运行。
金融发展水平的差别(例如,相对GDP的信用额度和相对GDP的相应股票市场的资本化程度),在所有者和管理者关系、企业和债权人的模式中,企业控制的市场活动水平可以很好地被记录.在完美资本市场,对于具有正的净现值投资机会的企业将一直获得资金。
然而,经济理论表明市场摩擦,诸如信息不对称和激励问题会使获得外部资本更加昂贵,并且具有盈利投资机会的企业不一定能够获取所需资本.这表明融资要素,例如内部产生资金数量、新债务和权益的可得性,共同决定了企业的投资决策.现今已经有大量考查外部资金可得性对投资决策的影响的实证资料(可参考,例如Fazzari(1998)、 Hoshi(1991)、 Chapman(1996)、Samuel(1998)).大多数研究结果表明金融变量例如现金流量有助于解释企业的投资水平。
这项研究结果解释表明企业投资受限于外部资金的可得性。
很多模型强调运行正常的金融中介和金融市场有助于改善信息不对称和交易成本,减缓不对称问题,从而促使储蓄资金投着长期和高回报的项目,并且提高资源的有效配置(参看Levine(1997)的评论文章)。
因而我们预期用于更加发达的金融体制的国家的企业将更容易获得外部融资.几位学者已经指出建立企业和金融中介机构可进一步缓解金融市场摩擦。
本科毕业设计(论文)外文翻译基本规范
本科毕业设计(论文)外文翻译基本规范一、要求1、与毕业论文分开单独成文。
2、两篇文献。
二、基本格式1、文献应以英、美等国家公开发表的文献为主(Journals from English speaking countries)。
2、毕业论文翻译是相对独立的,其中应该包括题目、作者(可以不翻译)、译文的出处(杂志的名称)(5号宋体、写在文稿左上角)、关键词、摘要、前言、正文、总结等几个部分。
3、文献翻译的字体、字号、序号等应与毕业论文格式要求完全一致。
4、文中所有的图表、致谢及参考文献均可以略去,但在文献翻译的末页标注:图表、致谢及参考文献已略去(见原文)。
(空一行,字体同正文)5、原文中出现的专用名词及人名、地名、参考文献可不翻译,并同原文一样在正文中标明出处。
二、毕业论文(设计)外文翻译(一)毕业论文(设计)外文翻译的内容要求外文翻译内容必须与所选课题相关,外文原文不少于6000个印刷符号。
译文末尾要用外文注明外文原文出处。
原文出处:期刊类文献书写方法:[序号]作者(不超过3人,多者用等或et al表示).题(篇)名[J].刊名(版本),出版年,卷次(期次):起止页次.原文出处:图书类文献书写方法:[序号]作者.书名[M].版本.出版地:出版者,出版年.起止页次.原文出处:论文集类文献书写方法:[序号]作者.篇名[A].编著者.论文集名[C]. 出版地:出版者,出版年.起止页次。
要求有外文原文复印件。
(二)毕业论文(设计)外文翻译的撰写与装订的格式规范第一部分:封面1.封面格式:见“毕业论文(设计)外文翻译封面”。
普通A4纸打印即可。
第二部分:外文翻译主题1.标题一级标题,三号字,宋体,顶格,加粗二级标题,四号字,宋体,顶格,加粗三级标题,小四号字,宋体,顶格,加粗2.正文小四号字,宋体。
第三部分:版面要求论文开本大小:210mm×297mm(A4纸)版芯要求:左边距:25mm,右边距:25mm,上边距:30mm,下边距:25mm,页眉边距:23mm,页脚边距:18mm字符间距:标准行距:1.25倍页眉页角:页眉的奇数页书写—浙江师范大学学士学位论文外文翻译。
毕业设计(论文)外文资料及译文(模板)
大连东软信息学院
毕业设计(论文)外文资料及译文
系所:
专业:
班级:
姓名:
学号:
大连东软信息学院
Dalian Neusoft University of Information
外文资料和译文格式要求
一、装订要求
1、外文资料原文(复印或打印)在前、译文在后、最后为指导教师评定成绩。
2、译文必须采用计算机输入、打印。
3、A4幅面打印,于左侧装订。
二、撰写要求
1、外文文献内容与所选课题相关。
2、本科学生译文汉字字数不少于4000字,高职学生译文汉字字数不少于2000字。
三、格式要求
1、译文字号:中文小四号宋体,英文小四号“Times New Roman”字型,全文统一,首行缩进2个中文字符,1.5倍行距。
2、译文页码:页码用阿拉伯数字连续编页,字体采用“Times New Roman”字体,字号小五,页底居中。
3、译文页眉:眉体使用单线,页眉说明五号宋体,居中“大连东软信息学院本科毕业设计(论文)译文”。
毕业设计论文外文文献翻译
毕业设计(论文)外文文献翻译院系:财务与会计学院年级专业:201*级财务管理姓名:学号:132148***附件: 财务风险管理【Abstract】Although financial risk has increased significantly in recent years risk and risk management are not contemporary issues。
The result of increasingly global markets is that risk may originate with events thousands of miles away that have nothing to do with the domestic market。
Information is available instantaneously which means that change and subsequent market reactions occur very quickly。
The economic climate and markets can be affected very quickly by changes in exchange rates interest rates and commodity prices。
Counterparties can rapidly become problematic。
As a result it is important to ensure financial risks are identified and managed appropriately. Preparation is a key component of risk management。
【Key Words】Financial risk,Risk management,YieldsI. Financial risks arising1.1What Is Risk1.1.1The concept of riskRisk provides the basis for opportunity. The terms risk and exposure have subtle differences in their meaning. Risk refers to the probability of loss while exposure is the possibility of loss although they are often used interchangeably。
外文文献翻译——参考格式
广东工业大学华立学院本科毕业设计(论文)外文参考文献译文及原文系部经济学部专业经济学年级 2007级班级名称 07经济学6班学号 16020706001学生姓名张瑜琴指导教师陈锶2011 年05月目录1挑战:小额贷款中的进入和商业银行的长期承诺 (1)2什么商业银行带给小额贷款和什么把他们留在外 (2)3 商业银行的四个模型进入小额贷款之内 (4)3.1内在的单位 (4)3.2财务子公司 (5)3.3策略的同盟 (5)3.4服务公司模型 (6)4 合法的形式和操作的结构比较 (8)5 服务的个案研究公司模型:厄瓜多尔和Haiti5 (9)1 挑战:小额贷款中的进入和商业银行的长期承诺商业银行已经是逐渐重要的运动员在拉丁美洲中的小额贷款服务的发展2到小额贷款市场是小额贷款的好消息客户因为银行能提供他们一完整类型的财务的服务,包括信用,储蓄和以费用为基础的服务。
整体而言,它也对小额贷款重要,因为与他们广泛的身体、财务的和人类。
如果商业银行变成重的运动员在小额贷款,他们能提供非常强烈的竞争到传统的小额贷款机构。
资源,银行能廉宜地发射而且扩张小额贷款服务rela tively。
如果商业广告银行在小额贷款中成为严重的运动员,他们能提出非常强烈的竞争给传统的小额贷款机构。
然而,小额贷款社区里面有知觉哪一商业银行进入进入小额贷款将会是短命或浅的。
举例来说,有知觉哪一商业银行首先可能不搬进小额贷款因为时候建立小额贷款操作到一个有利润的水平超过银行的标准投资时间地平线。
或,在进入小额贷款,银行之后可能移动在-上面藉由增加贷款数量销售取利润最大值-或者更坏的事,退出如果他们是不满意与小额贷款的收益性的水平。
这些知觉已经被特性加燃料商业银行的情形进入小额贷款和后来的出口之内。
在最极端的,一些开业者已经甚至宣布,”降低尺度死!”而且抛弃了与主意合作的商业银行。
在最 signific 看得到的地方,蚂蚁利益商业银行可能带给小额贷款,国际的ACCION 发展发射而且扩张的和一些商业银行的关系小额贷款操作。
外文参考文献译文及原文
广东工业大学华立学院本科毕业设计(论文)外文参考文献译文及原文系部城建学部专业土木工程年级 2011级班级名称 11土木工程9班学号 23031109000学生姓名刘林指导教师卢集富2015 年5 月目录一、项目成本管理与控制 0二、Project Budget Monitor and Control (1)三、施工阶段承包商在控制施工成本方面所扮演的作用 (2)四、The Contractor's Role in Building Cost Reduction After Design (4)一、外文文献译文(1)项目成本管理与控制随着市场竞争的激烈性越来越大,在每一个项目中,进行成本控制越发重要。
本文论述了在施工阶段,项目经理如何成功地控制项目预算成本。
本文讨论了很多方法。
它表明,要取得成功,项目经理必须关注这些成功的方法。
1.简介调查显示,大多数项目会碰到超出预算的问……功控制预算成本。
2.项目控制和监测的概念和目的Erel and Raz (2000)指出项目控制周期包括测量成……原因以及决定纠偏措施并采取行动。
监控的目的就是纠偏措施的...标范围内。
3.建立一个有效的控制体系为了实现预算成本的目标,项目管理者需要建立一……被监测和控制是非常有帮助的。
项目成功与良好的沟通密...决( Diallo and Thuillier, 2005)。
4.成本费用的检测和控制4.1对检测的优先顺序进行排序在施工阶段,很多施工活动是基于原来的计……用完了。
第四,项目管理者应该检测高风险活动,高风险活动最有...重要(Cotterell and Hughes, 1995)。
4.2成本控制的方法一个项目的主要费用包括员工成本、材料成本以及工期延误的成本。
为了控制这些成本费用,项目管理者首先应该建立一个成本控制系统:a)为财务数据的管理和分析工作落实责任人员b)确保按照项目的结构来合理分配所有的……它的变化--在成本控制线上准确地记录所有恰...围、变更、进度、质量)相结合由于一个工程项目......虑时间价值影响后的结果。
计算机专业毕业设计论文外文文献中英文翻译——java对象
1 . Introduction To Objects1.1The progress of abstractionAll programming languages provide abstractions. It can be argued that the complexity of the problems you’re able to solve is directly related to the kind and quality of abstraction。
By “kind” I mean,“What is it that you are abstracting?” Assembly language is a small abstraction of the underlying machine. Many so—called “imperative” languages that followed (such as FORTRAN,BASIC, and C) were abstractions of assembly language。
These languages are big improvements over assembly language,but their primary abstraction still requires you to think in terms of the structure of the computer rather than the structure of the problem you are trying to solve。
The programmer must establish the association between the machine model (in the “solution space,” which is the place where you’re modeling that problem, such as a computer) and the model of the problem that is actually being solved (in the “problem space,” which is the place where the problem exists). The effort required to perform this mapping, and the fact that it is extrinsic to the programming language,produces programs that are difficult to write and expensive to maintain,and as a side effect created the entire “programming methods” industry.The alter native to modeling the machine is to model the problem you’re trying to solve。
建筑学毕业设计的外文文献及译文
建筑学毕业设计的外文文献及译文文献、资料题目:《Advanced Encryption Standard》文献、资料发表(出版)日期:2004.10.25系(部):建筑工程系生:陆总LYY外文文献:Modern ArchitectureModern architecture, not to be confused with Contemporary architecture1, is a term given to a number of building styles with similar characteristics, primarily the simplification of form and the elimination of ornament. While the style was conceived early in the 20th century and heavily promoted by a few architects, architectural educators and exhibits, very few Modern buildings were built in the first half of the century. For three decades after the Second World War, however, it became the dominant architectural style for institutional and corporate building.1. OriginsSome historians see the evolution of Modern architecture as a social matter, closely tied to the project of Modernity and hence to the Enlightenment, a result of social and political revolutions.Others see Modern architecture as primarily driven by technological and engineering developments, and it is true that the availability of new building materials such as iron, steel, concrete and glass drove the invention of new building techniques as part of the Industrial Revolution. In 1796, Shrewsbury mill owner Charles Bage first used his "fireproof design, which relied on cast iron and brick with flag stone floors. Such construction greatly strengthened the structure of mills, which enabled them to accommodate much bigger machines. Due to poor knowledge of iron's properties as a construction material, a number of early mills collapsed. It was not until the early 1830s that Eaton Hodgkinson introduced the section beam, leading to widespread use of iron construction, this kind of austere industrial architecture utterly transformed the landscape of northern Britain, leading to the description, πDark satanic millsπof places like Manchester and parts of West Yorkshire. The Crystal Palace by Joseph Paxton at the Great Exhibition of 1851 was an early example of iron and glass construction; possibly the best example is the development of the tall steel skyscraper in Chicago around 1890 by William Le Baron Jenney and Louis Sullivan∙ Early structures to employ concrete as the chief means of architectural expression (rather than for purely utilitarian structure) include Frank Lloyd Wright,s Unity Temple, built in 1906 near Chicago, and Rudolf Steiner,s Second Goetheanum, built from1926 near Basel, Switzerland.Other historians regard Modernism as a matter of taste, a reaction against eclecticism and the lavish stylistic excesses of Victorian Era and Edwardian Art Nouveau.Whatever the cause, around 1900 a number of architects around the world began developing new architectural solutions to integrate traditional precedents (Gothic, for instance) with new technological possibilities- The work of Louis Sullivan and Frank Lloyd Wright in Chicago, Victor Horta in Brussels, Antoni Gaudi in Barcelona, Otto Wagner in Vienna and Charles Rennie Mackintosh in Glasgow, among many others, can be seen as a common struggle between old and new.2. Modernism as Dominant StyleBy the 1920s the most important figures in Modern architecture had established their reputations. The big three are commonly recognized as Le Corbusier in France, and Ludwig Mies van der Rohe and Walter Gropius in Germany. Mies van der Rohe and Gropius were both directors of the Bauhaus, one of a number of European schools and associations concerned with reconciling craft tradition and industrial technology.Frank Lloyd Wright r s career parallels and influences the work of the European modernists, particularly via the Wasmuth Portfolio, but he refused to be categorized with them. Wright was a major influence on both Gropius and van der Rohe, however, as well as on the whole of organic architecture.In 1932 came the important MOMA exhibition, the International Exhibition of Modem Architecture, curated by Philip Johnson. Johnson and collaborator Henry-Russell Hitchcock drew together many distinct threads and trends, identified them as stylistically similar and having a common purpose, and consolidated them into the International Style.This was an important turning point. With World War II the important figures of the Bauhaus fled to the United States, to Chicago, to the Harvard Graduate School of Design, and to Black Mountain College. While Modern architectural design never became a dominant style in single-dwelling residential buildings, in institutional and commercial architecture Modernism became the pre-eminent, and in the schools (for leaders of the profession) the only acceptable, design solution from about 1932 to about 1984.Architects who worked in the international style wanted to break with architectural tradition and design simple, unornamented buildings. The most commonly used materials are glass for the facade, steel for exterior support, and concrete for the floors and interior supports; floor plans were functional and logical. The style became most evident in the design of skyscrapers. Perhaps its most famous manifestations include the United Nations headquarters (Le Corbusier, Oscar Niemeyer, Sir Howard Robertson), the Seagram Building (Ludwig Mies van der Rohe), and Lever House (Skidmore, Owings, and Merrill), all in New York. A prominent residential example is the Lovell House (Richard Neutra) in Los Angeles.Detractors of the international style claim that its stark, uncompromisingly rectangular geometry is dehumanising. Le Corbusier once described buildings as πmachines for living,∖but people are not machines and it was suggested that they do not want to live in machines- Even Philip Johnson admitted he was πbored with the box∕,Since the early 1980s many architects have deliberately sought to move away from rectilinear designs, towards more eclectic styles. During the middle of the century, some architects began experimenting in organic forms that they felt were more human and accessible. Mid-century modernism, or organic modernism, was very popular, due to its democratic and playful nature. Alvar Aalto and Eero Saarinen were two of the most prolific architects and designers in this movement, which has influenced contemporary modernism.Although there is debate as to when and why the decline of the modern movement occurred, criticism of Modern architecture began in the 1960s on the grounds that it was universal, sterile, elitist and lacked meaning. Its approach had become ossified in a πstyleπthat threatened to degenerate into a set of mannerisms. Siegfried Giedion in the 1961 introduction to his evolving text, Space, Time and Architecture (first written in 1941), could begin ,,At the moment a certain confusion exists in contemporary architecture, as in painting; a kind of pause, even a kind of exhaustion/1At the Metropolitan Museum of Art, a 1961 symposium discussed the question πModern Architecture: Death or Metamorphosis?11In New York, the coup d r etat appeared to materialize in controversy around the Pan Am Building that loomed over Grand Central Station, taking advantage of the modernist real estate concept of πair rights,∖[l] In criticism by Ada Louise Huxtable and Douglas Haskell it was seen to ,,severπthe Park Avenue streetscape and πtarnishπthe reputations of its consortium of architects: Walter Gropius, Pietro Belluschi and thebuilders Emery Roth & Sons. The rise of postmodernism was attributed to disenchantment with Modern architecture. By the 1980s, postmodern architecture appeared triumphant over modernism, including the temple of the Light of the World, a futuristic design for its time Guadalajara Jalisco La Luz del Mundo Sede International; however, postmodern aesthetics lacked traction and by the mid-1990s, a neo-modern (or hypermodern) architecture had once again established international pre-eminence. As part of this revival, much of the criticism of the modernists has been revisited, refuted, and re-evaluated; and a modernistic idiom once again dominates in institutional and commercial contemporary practice, but must now compete with the revival of traditional architectural design in commercial and institutional architecture; residential design continues to be dominated by a traditional aesthetic.中文译文:现代建筑现代建筑,不被混淆与‘当代建筑’,是一个词给了一些建筑风格有类似的特点,主要的简化形式,消除装饰等.虽然风格的设想早在20世纪,并大量造就了一些建筑师、建筑教育家和展品,很少有现代的建筑物,建于20世纪上半叶.第二次大战后的三十年,但最终却成为主导建筑风格的机构和公司建设.1起源一些历史学家认为进化的现代建筑作为一个社会问题,息息相关的工程中的现代性, 从而影响了启蒙运动,导致社会和政治革命.另一些人认为现代建筑主要是靠技术和工程学的发展,那就是获得新的建筑材料,如钢铁,混凝土和玻璃驱车发明新的建筑技术,它作为工业革命的一部分.1796年,Shrewsbury查尔斯bage首先用他的‘火’的设计,后者则依靠铸铁及砖与石材地板.这些建设大大加强了结构,使它们能够容纳更大的机器.由于作为建筑材料特性知识缺乏,一些早期建筑失败.直到1830年初,伊顿Hodgkinson预计推出了型钢梁,导致广泛使用钢架建设,工业结构完全改变了这种窘迫的面貌,英国北部领导的描述,〃黑暗魔鬼作坊〃的地方如曼彻斯特和西约克郡.水晶宫由约瑟夫paxton的重大展览,1851年,是一个早期的例子, 钢铁及玻璃施工;可能是一个最好的例子,就是1890年由William乐男爵延长和路易沙利文在芝加哥附近发展的高层钢结构摩天楼.早期结构采用混凝土作为行政手段的建筑表达(而非纯粹功利结构),包括建于1906年在芝加哥附近,劳埃德赖特的统一宫,建于1926 年瑞士巴塞尔附近的鲁道夫斯坦纳的第二哥特堂,.但无论原因为何,约有1900多位建筑师,在世界各地开始制定新的建筑方法,将传统的先例(比如哥特式)与新的技术相结合的可能性.路易沙利文和赖特在芝加哥工作,维克多奥尔塔在布鲁塞尔,安东尼高迪在巴塞罗那,奥托瓦格纳和查尔斯景mackintosh格拉斯哥在维也纳,其中之一可以看作是一个新与旧的共同斗争.2现代主义风格由1920年代的最重要人物,在现代建筑里确立了自己的名声.三个是公认的柯布西耶在法国,密斯范德尔德罗和瓦尔特格罗皮乌斯在德国.密斯范德尔德罗和格罗皮乌斯为董事的包豪斯,其中欧洲有不少学校和有关团体学习调和工艺和传统工业技术.赖特的建筑生涯中,也影响了欧洲建筑的现代艺术,特别是通过瓦斯穆特组合但他拒绝被归类与他们.赖特与格罗皮乌斯和Van der德罗对整个有机体系有重大的影响.在1932年来到的重要moma展览,是现代建筑艺术的国际展览,艺术家菲利普约翰逊. 约翰逊和合作者亨利-罗素阁纠集许多鲜明的线索和趋势,内容相似,有一个共同的目的, 巩固了他们融入国际化风格这是一个重要的转折点.在二战的时间包豪斯的代表人物逃到美国,芝加哥,到哈佛大学设计黑山书院.当现代建筑设计从未成为主导风格单一的住宅楼,在成为现代卓越的体制和商业建筑,是学校(专业领导)的唯一可接受的,设计解决方案,从约1932年至约1984 年.那些从事国际风格的建筑师想要打破传统建筑和简单的没有装饰的建筑物。
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。
外文文献翻译范例
StatusComplete
Type:Office
Location:Hong Kong
Construction started:18 April 1985
Completed:1990
Opening:17 May 1990
HeightAntenna spire:367.4 m (1,205.4 ft)
2011年6月8日
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建筑师:Bruce Graham, design partner, Skidmore, Owings and Merrill
地点:Chicago
甲方:Sears Roebuck and Company
工程师:Fazlur Khan of Skidmore, Owings and Merrill.项目年份:2008
香港1985年4月18日开工建设1990年完成1990年5月17日开幕高度天线尖顶三百六十七点四米2418英尺屋顶三百一十五点米10335英尺顶层二百八十八点二米九百四十五点五英尺技术细节地上楼层数724层楼建筑面积一十三点五万平方米1450000平方英尺电梯数45由奥的斯电梯公司生产的设计与施工主要承建商香港建设控股有限公司引文需要熊谷组香港贝聿铭建筑师事务所建筑师事务所谢尔曼西贡有限公司sl的托马斯博阿达莱斯利罗伯逊结构工程师协会rllp参考文献对中国塔简称中银大厦银行是中环香港最知名的摩天大楼之一
毕业设计论文外文文献翻译
xxxx大学xxx学院毕业设计(论文)外文文献翻译系部xxxx专业xxxx学生姓名xxxx 学号xxxx指导教师xxxx 职称xxxx2013年3 月Introducing the Spring FrameworkThe Spring Framework: a popular open source application framework that addresses many of the issues outlined in this book. This chapter will introduce the basic ideas of Spring and dis-cuss the central “bean factory” lightweight Inversion-of-Control (IoC) container in detail.Spring makes it particularly easy to implement lightweight, yet extensible, J2EE archi-tectures. It provides an out-of-the-box implementation of the fundamental architectural building blocks we recommend. Spring provides a consistent way of structuring your applications, and provides numerous middle tier features that can make J2EE development significantly easier and more flexible than in traditional approaches.The basic motivations for Spring are:To address areas not well served by other frameworks. There are numerous good solutions to specific areas of J2EE infrastructure: web frameworks, persistence solutions, remoting tools, and so on. However, integrating these tools into a comprehensive architecture can involve significant effort, and can become a burden. Spring aims to provide an end-to-end solution, integrating spe-cialized frameworks into a coherent overall infrastructure. Spring also addresses some areas that other frameworks don’t. For example, few frameworks address generic transaction management, data access object implementation, and gluing all those things together into an application, while still allowing for best-of-breed choice in each area. Hence we term Spring an application framework, rather than a web framework, IoC or AOP framework, or even middle tier framework.To allow for easy adoption. A framework should be cleanly layered, allowing the use of indi-vidual features without imposing a whole worldview on the application. Many Spring features, such as the JDBC abstraction layer or Hibernate integration, can be used in a library style or as part of the Spring end-to-end solution.To deliver ease of use. As we’ve noted, J2EE out of the box is relatively hard to use to solve many common problems. A good infrastructure framework should make simple tasks simple to achieve, without forcing tradeoffs for future complex requirements (like distributed transactions) on the application developer. It should allow developers to leverage J2EE services such as JTA where appropriate, but to avoid dependence on them in cases when they are unnecessarily complex.To make it easier to apply best practices. Spring aims to reduce the cost of adhering to best practices such as programming to interfaces, rather than classes, almost to zero. However, it leaves the choice of architectural style to the developer.Non-invasiveness. Application objects should have minimal dependence on the framework. If leveraging a specific Spring feature, an object should depend only on that particular feature, whether by implementing a callback interface or using the framework as a class library. IoC and AOP are the key enabling technologies for avoiding framework dependence.Consistent configuration. A good infrastructure framework should keep application configuration flexible and consistent, avoiding the need for custom singletons and factories. A single style should be applicable to all configuration needs, from the middle tier to web controllers.Ease of testing. Testing either whole applications or individual application classes in unit tests should be as easy as possible. Replacing resources or application objects with mock objects should be straightforward.To allow for extensibility. Because Spring is itself based on interfaces, rather than classes, it is easy to extend or customize it. Many Spring components use strategy interfaces, allowing easy customization.A Layered Application FrameworkChapter 6 introduced the Spring Framework as a lightweight container, competing with IoC containers such as PicoContainer. While the Spring lightweight container for JavaBeans is a core concept, this is just the foundation for a solution for all middleware layers.Basic Building Blockspring is a full-featured application framework that can be leveraged at many levels. It consists of multi-ple sub-frameworks that are fairly independent but still integrate closely into a one-stop shop, if desired. The key areas are:Bean factory. The Spring lightweight IoC container, capable of configuring and wiring up Java-Beans and most plain Java objects, removing the need for custom singletons and ad hoc configura-tion. Various out-of-the-box implementations include an XML-based bean factory. The lightweight IoC container and its Dependency Injection capabilities will be the main focus of this chapter.Application context. A Spring application context extends the bean factory concept by adding support for message sources and resource loading, and providing hooks into existing environ-ments. Various out-of-the-box implementations include standalone application contexts and an XML-based web application context.AOP framework. The Spring AOP framework provides AOP support for method interception on any class managed by a Spring lightweight container.It supports easy proxying of beans in a bean factory, seamlessly weaving in interceptors and other advice at runtime. Chapter 8 dis-cusses the Spring AOP framework in detail. The main use of the Spring AOP framework is to provide declarative enterprise services for POJOs.Auto-proxying. Spring provides a higher level of abstraction over the AOP framework and low-level services, which offers similar ease-of-use to .NET within a J2EE context. In particular, the provision of declarative enterprise services can be driven by source-level metadata.Transaction management. Spring provides a generic transaction management infrastructure, with pluggable transaction strategies (such as JTA and JDBC) and various means for demarcat-ing transactions in applications. Chapter 9 discusses its rationale and the power and flexibility that it offers.DAO abstraction. Spring defines a set of generic data access exceptions that can be used for cre-ating generic DAO interfaces that throw meaningful exceptions independent of the underlying persistence mechanism. Chapter 10 illustrates the Spring support for DAOs in more detail, examining JDBC, JDO, and Hibernate as implementation strategies.JDBC support. Spring offers two levels of JDBC abstraction that significantly ease the effort of writing JDBC-based DAOs: the org.springframework.jdbc.core package (a template/callback approach) and the org.springframework.jdbc.object package (modeling RDBMS operations as reusable objects). Using the Spring JDBC packages can deliver much greater pro-ductivity and eliminate the potential for common errors such as leaked connections, compared with direct use of JDBC. The Spring JDBC abstraction integrates with the transaction and DAO abstractions.Integration with O/R mapping tools. Spring provides support classesfor O/R Mapping tools like Hibernate, JDO, and iBATIS Database Layer to simplify resource setup, acquisition, and release, and to integrate with the overall transaction and DAO abstractions. These integration packages allow applications to dispense with custom ThreadLocal sessions and native transac-tion handling, regardless of the underlying O/R mapping approach they work with.Web MVC framework. Spring provides a clean implementation of web MVC, consistent with the JavaBean configuration approach. The Spring web framework enables web controllers to be configured within an IoC container, eliminating the need to write any custom code to access business layer services. It provides a generic DispatcherServlet and out-of-the-box controller classes for command and form handling. Request-to-controller mapping, view resolution, locale resolution and other important services are all pluggable, making the framework highly extensi-ble. The web framework is designed to work not only with JSP, but with any view technology, such as Velocity—without the need for additional bridges. Chapter 13 discusses web tier design and the Spring web MVC framework in detail.Remoting support. Spring provides a thin abstraction layer for accessing remote services without hard-coded lookups, and for exposing Spring-managed application beans as remote services. Out-of-the-box support is inc luded for RMI, Caucho’s Hessian and Burlap web service protocols, and WSDL Web Services via JAX-RPC. Chapter 11 discusses lightweight remoting.While Spring addresses areas as diverse as transaction management and web MVC, it uses a consistent approach everywhere. Once you have learned the basic configuration style, you will be able to apply it in many areas. Resources, middle tier objects, and web components are all set up using the same bean configuration mechanism. You can combine your entireconfiguration in one single bean definition file or split it by application modules or layers; the choice is up to you as the application developer. There is no need for diverse configuration files in a variety of formats, spread out across the application.Spring on J2EEAlthough many parts of Spring can be used in any kind of Java environment, it is primarily a J2EE application framework. For example, there are convenience classes for linking JNDI resources into a bean factory, such as JDBC DataSources and EJBs, and integration with JTA for distributed transaction management. In most cases, application objects do not need to work with J2EE APIs directly, improving reusability and meaning that there is no need to write verbose, hard-to-test, JNDI lookups.Thus Spring allows application code to seamlessly integrate into a J2EE environment without being unnecessarily tied to it. You can build upon J2EE services where it makes sense for your application, and choose lighter-weight solutions if there are no complex requirements. For example, you need to use JTA as transaction strategy only if you face distributed transaction requirements. For a single database, there are alternative strategies that do not depend on a J2EE container. Switching between those transac-tion strategies is merely a matter of configuration; Spring’s consistent abstraction avoids any need to change application code.Spring offers support for accessing EJBs. This is an important feature (and relevant even in a book on “J2EE without EJB”) because the u se of dynamic proxies as codeless client-side business delegates means that Spring can make using a local stateless session EJB an implementation-level, rather than a fundamen-tal architectural, choice.Thus if you want to use EJB, you can within a consistent architecture; however, you do not need to make EJB the cornerstone of your architecture. This Spring feature can make devel-oping EJB applications significantly faster, because there is no need to write custom code in service loca-tors or business delegates. Testing EJB client code is also much easier, because it only depends on the EJB’s Business Methods interface (which is not EJB-specific), not on JNDI or the EJB API.Spring also provides support for implementing EJBs, in the form of convenience superclasses for EJB implementation classes, which load a Spring lightweight container based on an environment variable specified in the ejb-jar.xml deployment descriptor. This is a powerful and convenient way of imple-menting SLSBs or MDBs that are facades for fine-grained POJOs: a best practice if you do choose to implement an EJB application. Using this Spring feature does not conflict with EJB in any way—it merely simplifies following good practice.Introducing the Spring FrameworkThe main aim of Spring is to make J2EE easier to use and promote good programming practice. It does not reinvent the wheel; thus you’ll find no logging packages in Spring, no connection pools, no distributed transaction coordinator. All these features are provided by other open source projects—such as Jakarta Commons Logging (which Spring uses for all its log output), Jakarta Commons DBCP (which can be used as local DataSource), and ObjectWeb JOTM (which can be used as transaction manager)—or by your J2EE application server. For the same reason, Spring doesn’t provide an O/R mapping layer: There are good solutions for this problem area, such as Hibernate and JDO.Spring does aim to make existing technologies easier to use. For example, although Spring is not in the business of low-level transactioncoordination, it does provide an abstraction layer over JTA or any other transaction strategy. Spring is also popular as middle tier infrastructure for Hibernate, because it provides solutions to many common issues like SessionFactory setup, ThreadLocal sessions, and exception handling. With the Spring HibernateTemplate class, implementation methods of Hibernate DAOs can be reduced to one-liners while properly participating in transactions.The Spring Framework does not aim to replace J2EE middle tier services as a whole. It is an application framework that makes accessing low-level J2EE container ser-vices easier. Furthermore, it offers lightweight alternatives for certain J2EE services in some scenarios, such as a JDBC-based transaction strategy instead of JTA when just working with a single database. Essentially, Spring enables you to write appli-cations that scale down as well as up.Spring for Web ApplicationsA typical usage of Spring in a J2EE environment is to serve as backbone for the logical middle tier of a J2EE web application. Spring provides a web application context concept, a powerful lightweight IoC container that seamlessly adapts to a web environment: It can be accessed from any kind of web tier, whether Struts, WebWork, Tapestry, JSF, Spring web MVC, or a custom solution.The following code shows a typical example of such a web application context. In a typical Spring web app, an applicationContext.xml file will reside in the WEB-INF directory, containing bean defini-tions according to the “spring-beans” DTD. In such a bean definition XML file, business objects and resources are defined, for example, a “myDataSource” bean, a “myInventoryManager” bean, and a “myProductManager” bean. Spring takes care of their configuration, their wiring up, and their lifecycle.<beans><bean id=”myDataSource” class=”org.springframework.jdbc. datasource.DriverManagerDataSource”><property name=”driverClassName”> <value>com.mysql.jdbc.Driver</value></property> <property name=”url”><value>jdbc:mysql:myds</value></property></bean><bean id=”myInventoryManager” class=”ebusiness.DefaultInventoryManager”> <property name=”dataSource”><ref bean=”myDataSource”/> </property></bean><bean id=”myProductManager” class=”ebusiness.DefaultProductManage r”><property name=”inventoryManager”><ref bean=”myInventoryManager”/> </property><property name=”retrieveCurrentStock”> <value>true</value></property></bean></beans>By default, all such beans have “singleton” scope: one instance per context. The “myInventoryManager” bean will automatically be wired up with the defined DataSource, while “myProductManager” will in turn receive a reference to the “myInventoryManager” bean. Those objects (traditionally called “beans” in Spring terminology) need to expos e only the corresponding bean properties or constructor arguments (as you’ll see later in this chapter); they do not have to perform any custom lookups.A root web application context will be loaded by a ContextLoaderListener that is defined in web.xml as follows:<web-app><listener> <listener-class>org.springframework.web.context.ContextLoaderListener</listener-class></listener>...</web-app>After initialization of the web app, the root web application context will be available as a ServletContext attribute to the whole web application, in the usual manner. It can be retrieved from there easily via fetching the corresponding attribute, or via a convenience method in org.springframework.web. context.support.WebApplicationContextUtils. This means that the application context will be available in any web resource with access to the ServletContext, like a Servlet, Filter, JSP, or Struts Action, as follows:WebApplicationContext wac = WebApplicationContextUtils.getWebApplicationContext(servletContext);The Spring web MVC framework allows web controllers to be defined as JavaBeans in child application contexts, one per dispatcher servlet. Such controllers can express dependencies on beans in the root application context via simple bean references. Therefore, typical Spring web MVC applications never need to perform a manual lookup of an application context or bean factory, or do any other form of lookup.Neither do other client objects that are managed by an application context themselves: They can receive collaborating objects as bean references.The Core Bean FactoryIn the previous section, we have seen a typical usage of the Spring IoC container in a web environment: The provided convenience classes allow for seamless integration without having to worry about low-level container details. Nevertheless, it does help to look at the inner workings to understand how Spring manages the container. Therefore, we will now look at the Spring bean container in more detail, starting at the lowest building block: the bean factory. Later, we’ll continue with resource setup and details on the application context concept.One of the main incentives for a lightweight container is to dispense with the multitude of custom facto-ries and singletons often found in J2EE applications. The Spring bean factory provides one consistent way to set up any number of application objects, whether coarse-grained components or fine-grained busi-ness objects. Applying reflection and Dependency Injection, the bean factory can host components that do not need to be aware of Spring at all. Hence we call Spring a non-invasive application framework.Fundamental InterfacesThe fundamental lightweight container interface is org.springframework.beans.factory.Bean Factory. This is a simple interface, which is easy to implement directly in the unlikely case that none of the implementations provided with Spring suffices. The BeanFactory interface offers two getBean() methods for looking up bean instances by String name, with the option to check for a required type (and throw an exception if there is a type mismatch).public interface BeanFactory {Object getBean(String name) throws BeansException;Object getBean(String name, Class requiredType) throws BeansException;boolean containsBean(String name);boolean isSingleton(String name) throws NoSuchBeanDefinitionException;String[] getAliases(String name) throws NoSuchBeanDefinitionException;}The isSingleton() method allows calling code to check whether the specified name represents a sin-gleton or prototype bean definition. In the case of a singleton bean, all calls to the getBean() method will return the same object instance. In the case of a prototype bean, each call to getBean() returns an inde-pendent object instance, configured identically.The getAliases() method will return alias names defined for the given bean name, if any. This mecha-nism is used to provide more descriptive alternative names for beans than are permitted in certain bean factory storage representations, such as XML id attributes.The methods in most BeanFactory implementations are aware of a hierarchy that the implementation may be part of. If a bean is not foundin the current factory, the parent factory will be asked, up until the root factory. From the point of view of a caller, all factories in such a hierarchy will appear to be merged into one. Bean definitions in ancestor contexts are visible to descendant contexts, but not the reverse.All exceptions thrown by the BeanFactory interface and sub-interfaces extend org.springframework. beans.BeansException, and are unchecked. This reflects the fact that low-level configuration prob-lems are not usually recoverable: Hence, application developers can choose to write code to recover from such failures if they wish to, but should not be forced to write code in the majority of cases where config-uration failure is fatal.Most implementations of the BeanFactory interface do not merely provide a registry of objects by name; they provide rich support for configuring those objects using IoC. For example, they manage dependen-cies between managed objects, as well as simple properties. In the next section, we’ll look at how such configuration can be expressed in a simple and intuitive XML structure.The sub-interface org.springframework.beans.factory.ListableBeanFactory supports listing beans in a factory. It provides methods to retrieve the number of beans defined, the names of all beans, and the names of beans that are instances of a given type:public interface ListableBeanFactory extends BeanFactory {int getBeanDefinitionCount();String[] getBeanDefinitionNames();String[] getBeanDefinitionNames(Class type);boolean containsBeanDefinition(String name);Map getBeansOfType(Class type, boolean includePrototypes,boolean includeFactoryBeans) throws BeansException}The ability to obtain such information about the objects managed by a ListableBeanFactory can be used to implement objects that work with a set of other objects known only at runtime.In contrast to the BeanFactory interface, the methods in ListableBeanFactory apply to the current factory instance and do not take account of a hierarchy that the factory may be part of. The org.spring framework.beans.factory.BeanFactoryUtils class provides analogous methods that traverse an entire factory hierarchy.There are various ways to leverage a Spring bean factory, ranging from simple bean configuration to J2EE resource integration and AOP proxy generation. The bean factory is the central, consistent way of setting up any kind of application objects in Spring, whether DAOs, business objects, or web controllers. Note that application objects seldom need to work with the BeanFactory interface directly, but are usu-ally configured and wired by a factory without the need for any Spring-specific code.For standalone usage, the Spring distribution provides a tiny spring-core.jar file that can be embed-ded in any kind of application. Its only third-party dependency beyond J2SE 1.3 (plus JAXP for XML parsing) is the Jakarta Commons Logging API.The bean factory is the core of Spring and the foundation for many other services that the framework offers. Nevertheless, the bean factory can easily be used stan-dalone if no other Spring services are required.Derivative:networkSpring 框架简介Spring框架:这是一个流行的开源应用框架,它可以解决很多问题。
本科毕业设计外文文献及译文1
本科毕业设计外文文献及译文文献、资料题目:Transit Route Network Design Problem:Review文献、资料来源:网络文献、资料发表(出版)日期:2007.1院(部):xxx专业:xxx班级:xxx姓名:xxx学号:xxx指导教师:xxx翻译日期:xxx外文文献:Transit Route Network Design Problem:Review Abstract:Efficient design of public transportation networks has attracted much interest in the transport literature and practice,with manymodels and approaches for formulating the associated transit route network design problem _TRNDP_having been developed.The presentpaper systematically presents and reviews research on the TRNDP based on the three distinctive parts of the TRNDP setup:designobjectives,operating environment parameters and solution approach.IntroductionPublic transportation is largely considered as a viable option for sustainable transportation in urban areas,offering advantages such as mobility enhancement,traffic congestion and air pollution reduction,and energy conservation while still preserving social equity considerations. Nevertheless,in the past decades,factors such as socioeconomic growth,the need for personalized mobility,the increase in private vehicle ownership and urban sprawl have led to a shift towards private vehicles and a decrease in public transportation’s share in daily commuting (Sinha2003;TRB2001;EMTA2004;ECMT2002;Pucher et al.2007).Efforts for encouraging public transportation use focuses on improving provided services such as line capacity,service frequency,coverage,reliability,comfort and service quality which are among the most important parameters for an efficient public transportation system(Sinha2003;Vuchic2004.) In this context,planning and designing a cost and service efficientpublic transportation network is necessary for improving its competitiveness and market share. The problem that formally describes the design of such a public transportation network is referred to as the transit route network design problem(TRNDP);it focuses on the optimization of a number of objectives representing the efficiency of public transportation networks under operational and resource constraints such as the number and length of public transportation routes, allowable service frequencies,and number of available buses(Chakroborty2003;Fan and Machemehl2006a,b).The practical importance of designing public transportation networks has attractedconsiderable interest in the research community which has developed a variety of approaches and modelsfor the TRNDP including different levels of design detail and complexity as well as interesting algorithmic innovations.In thispaper we offer a structured review of approaches for the TRNDP;researchers will obtain a basis for evaluating existing research and identifying future research paths for further improving TRNDP models.Moreover,practitioners will acquire a detailed presentation of both the process and potential tools for automating the design of public transportation networks,their characteristics,capabilities,and strengths.Design of Public Transportation NetworksNetwork design is an important part of the public transportation operational planning process_Ceder2001_.It includes the design of route layouts and the determination of associated operational characteristics such as frequencies,rolling stock types,and so on As noted by Ceder and Wilson_1986_,network design elements are part of the overall operational planning process for public transportation networks;the process includes five steps:_1_design of routes;_2_ setting frequencies;_3_developing timetables;_4_scheduling buses;and_5_scheduling drivers. Route layout design is guided by passenger flows:routes are established to provide direct or indirect connection between locations and areas that generate and attract demand for transit travel, such as residential and activity related centers_Levinson1992_.For example,passenger flows between a central business district_CBD_and suburbs dictate the design of radial routes while demand for trips between different neighborhoods may lead to the selection of a circular route connecting them.Anticipated service coverage,transfers,desirable route shapes,and available resources usually determine the structure of the route network.Route shapes areusually constrained by their length and directness_route directness implies that route shapes are as straight as possible between connected points_,the usage of given roads,and the overlapping with other transit routes.The desirable outcome is a set of routesconnecting locations within a service area,conforming to given design criteria.For each route, frequencies and bus types are the operational characteristics typically determined through design. Calculations are based on expected passenger volumes along routes that are estimated empirically or by applying transit assignmenttechniques,under frequency requirement constraints_minimum and maximum allowedfrequencies guaranteeing safety and tolerable waiting times,respectively_,desired load factors, fleet size,and availability.These steps as well as the overall design.process have been largely based upon practical guidelines,the expert judgment of transit planners,and operators experience_Baaj and Mahmassani1991_.Two handbooks by Black _1995_and Vuchic_2004_outline frameworks to be followed by planners when designing a public transportation network that include:_1_establishing the objectives for the network;_2_ defining the operational environment of the network_road structure,demand patterns,and characteristics_;_3_developing;and_4_evaluating alternative public transportation networks.Despite the extensive use of practical guidelines and experience for designing transit networks,researchers have argued that empirical rules may not be sufficient for designing an efficient transit network and improvements may lead to better quality and more efficient services. For example,Fan and Machemehl_2004_noted that researchers and practitioners have been realizing that systematic and integrated approaches are essential for designing economically and operationally efficient transit networks.A systematic design process implies clear and consistent steps and associated techniques for designing a public transportation network,which is the scope of the TRNDP.TRNDP:OverviewResearch has extensively examined the TRNDP since the late1960s.In1979,Newell discussed previous research on the optimal design of bus routes and Hasselström_1981_ analyzed relevant studies and identified the major features of the TRNDP as demand characteristics,objective functions,constraints,passengerbehavior,solution techniques,and computational time for solving the problem.An extensive review of existing work on transit network design was provided by Chua_1984_who reported five types of transit system planning:_1_manual;_2_marketanalysis;_3_systems analysis;_4_systems analysis with interactive graphics;and_5_ mathematical optimization approach.Axhausemm and Smith_1984_analyzed existing heuristic algorithms for formulating the TRNDP in Europe,tested them,anddiscussed their potential implementation in the United States.Ceder and Wilson_1986_reportedprior work on the TRNDP and distinguished studies into those that deal with idealized networks and to those that focus on actual routes,suggesting that the main features of the TRNDP include demand characteristics,objectivesand constraints,and solution methods.At the same period,Van Nes et al._1988_grouped TRNDP models into six categories:_1_ analytical models for relating parameters of the public transportation system;_2_models determining the links to be used for public transportation route construction;_3_models determining routes only;_4_models assigning frequencies to a set of routes;_5_two-stage models for constructing routes and then assigning frequencies;and_6_models for simultaneously determining routes and frequencies.Spacovic et al._1994_and Spacovic and Schonfeld_1994_proposed a matrix organization and classified each study according to design parameters examined,objectives anticipated,network geometry,and demand characteristics. Ceder and Israeli_1997_suggested broad categorizations for TRNDP models into passenger flow simulation and mathematical programming models.Russo_1998_adopted the same categorization and noted that mathematical programming models guarantee optimal transit network design but sacrifice the level of detail in passenger representation and design parameters, while simulation models address passenger behavior but use heuristic procedures obtaining a TRNDP solution.Ceder_2001_enhanced his earlier categorization by classifying TRNDP models into simulation,ideal network,and mathematical programming models.Finally,in a recent series of studies,Fan and Machemehl_2004,2006a,b_divided TRNDP approaches into practical approaches,analytical optimization models for idealized conditions,and metaheuristic procedures for practical problems.The TRNDP is an optimization problem where objectives are defined,its constraints are determined,and a methodology is selected and validated for obtaining an optimal solution.The TRNDP is described by the objectives of the public transportation network service to be achieved, the operational characteristics and environment under which the network will operate,and the methodological approach for obtaining the optimal network design.Based on this description of the TRNDP,we propose a three-layer structure for organizing TRNDP approaches_Objectives, Parameters,and Methodology_.Each layer includes one or more items that characterize each study.The“Objectives”layer incorporates the goals set when designing a public transportation system such as the minimization of the costs of the system or the maximization of the quality of services provided.The“Parameters”layer describes the operating environment and includes both the design variables expected to be derived for the transit network_route layouts,frequencies_as well as environmental and operational parameters affecting and constraining that network_for example,allowable frequencies,desired load factors,fleet availability,demand characteristics and patterns,and so on_.Finally,the“Methodology”layer covers the logical–mathematical framework and algorithmic tools necessary to formulate and solve the TRNDP.The proposed structure follows the basic concepts toward setting up a TRNDP:deciding upon the objectives, selecting the transit network items and characteristics to be designed,setting the necessary constraints for the operating environment,and formulating and solving the problem. TRNDP:ObjectivesPublic transportation serves a very important social role while attempting to do this at the lowest possible operating cost.Objectives for designing daily operations of a public transportation system should encompass both angles.The literature suggests that most studies actually focus on both the service and economic efficiency when designing such a system. Practical goals for the TRNDP can be briefly summarized as follows_Fielding1987;van Oudheudsen et al.1987;Black1995_:_1_user benefit maximization;_2_operator cost minimization;_3_total welfare maximization;_4_capacity maximization;_5_energy conservation—protection of the environment;and_6_individual parameter optimization.Mandl_1980_indicated that public transportation systems have different objectives to meet. He commented,“even a single objective problem is difficult to attack”_p.401_.Often,these objectives are controversial since cutbacks in operating costs may require reductions in the quality of services.Van Nes and Bovy_2000_pointed out that selected objectives influence the attractiveness and performance of a public transportation network.According to Ceder and Wilson_1986_,minimization of generalized cost or time or maximization of consumer surplus were the most common objectives selected when developing transit network design models. Berechman_1993_agreed that maximization of total welfare is the most suitable objective for designing a public transportation system while Van Nes and Bovy_2000_argued that the minimization of total user and system costs seem the most suit able and less complicatedobjective_compared to total welfare_,while profit maximization leads to nonattractive public transportation networks.As can be seen in Table1,most studies seek to optimize total welfare,which incorporates benefits to the user and to the er benefits may include travel,access and waiting cost minimization,minimization of transfers,and maximization of coverage,while benefits for the system are maximum utilization and quality of service,minimization of operating costs, maximization of profits,and minimization of the fleet size used.Most commonly,total welfare is represented by the minimization of user and system costs.Some studies address specific objectives from the user,theoperator,or the environmental perspective.Passenger convenience,the number of transfers, profit and capacity maximization,travel time minimization,and fuel consumption minimization are such objectives.These studies either attempt to simplify the complex objective functions needed to setup the TRNDP_Newell1979;Baaj and Mahmassani1991;Chakroborty and Dwivedi2002_,or investigate specific aspects of the problem,such as objectives_Delle Site and Fillipi2001_,and the solution methodology_Zhao and Zeng2006;Yu and Yang2006_.Total welfare is,in a sense,a compromise between objectives.Moreover,as reported by some researchers such as Baaj and Mahmassani_1991_,Bielli et al._2002_,Chackroborty and Dwivedi_2002_,and Chakroborty_2003_,transit network design is inherently a multiobjective problem.Multiobjective models for solving the TRNDP have been based on the calculation of indicators representing different objectives for the problem at hand,both from the user and operator perspectives,such as travel and waiting times_user_,and capacity and operating costs _operator_.In their multiobjective model for the TRNDP,Baaj and Majmassani_1991_relied on the planner’s judgment and experience for selecting the optimal public transportation network,based on a set of indicators.In contrast,Bielli et al._2002_and Chakroborty and Dwivedi_2002_,combined indicators into an overall,weighted sum value, which served as the criterion for determining the optimaltransit network.TRNDP:ParametersThere are multiple characteristics and design attributes to consider for a realistic representation of a public transportation network.These form the parameters for the TRNDP.Part of these parameters is the problem set of decision variables that define its layout and operational characteristics_frequencies,vehicle size,etc._.Another set of design parameters represent the operating environment_network structure,demand characters,and patterns_, operational strategies and rules,and available resources for the public transportation network. These form the constraints needed to formulate the TRNDP and are,a-priori fixed,decided upon or assumed.Decision VariablesMost common decision variables for the TRNDP are the routes and frequencies of the public transportation network_Table1_.Simplified early studies derived optimal route spacing between predetermined parallel or radial routes,along with optimal frequencies per route_Holroyd1967; Byrne and Vuchic1972;Byrne1975,1976;Kocur and Hendrickson1982;Vaughan1986_,while later models dealt with the development of optimal route layouts and frequency determination. Other studies,additionally,considered fares_Kocur and Hendrickson1982;Morlok and Viton 1984;Chang and Schonfeld1991;Chien and Spacovic2001_,zones_Tsao and Schonfeld1983; Chang and Schonfeld1993a_,stop locations_Black1979;Spacovic and Schonfeld1994; Spacovic et al.1994;Van Nes2003;Yu and Yang2006_and bus types_Delle Site and Filippi 2001_.Network StructureSome early studies focused on the design of systems in simplified radial_Byrne1975;Black 1979;Vaughan1986_,or rectangular grid road networks_Hurdle1973;Byrne and Vuchic1972; Tsao and Schonfeld1984_.However,most approaches since the1980s were either applied to realistic,irregular grid networks or the network structure was of no importance for the proposed model and therefore not specified at all.Demand PatternsDemand patterns describe the nature of the flows of passengers expected to be accommodated by the public transportation network and therefore dictate its structure.For example,transit trips from a number of origins_for example,stops in a neighborhood_to a single destination_such as a bus terminal in the CBD of a city_and vice-versa,are characterized as many-to-one_or one-tomany_transit demand patterns.These patterns are typically encountered in public transportation systems connecting CBDs with suburbs and imply a structure of radial orparallel routes ending at a single point;models for patterns of that type have been proposed by Byrne and Vuchic_1972_,Salzborn_1972_,Byrne_1975,1976_,Kocur and Hendrickson _1982_,Morlok and Viton_1984_,Chang and Schonfeld_1991,1993a_,Spacovic and Schonfeld_1994_,Spacovic et al._1994_,Van Nes_2003_,and Chien et al._2003_.On the other hand,many-to-many demand patterns correspond to flows between multiple origins and destinations within an urban area,suggesting that the public transportation network is expected to connect various points in an area.Demand CharacteristicsDemand can be characterized either as“fixed”_or“inelastic”_or“elastic”;the later meaning that demand is affected by the performance and services provided by the public transportation network.Lee and Vuchic_2005_distinguished between two types of elastic demand:_1_demand per mode affected by transportation services,with total demand for travel kept constant;and_2_total demand for travel varying as a result of the performance of the transportation system and its modes.Fan and Machemehl_2006b_noted that the complexity of the TRNDP has led researchers intoassuming fixed demand,despite its inherent elastic nature.However,since the early1980s, studies included aspects of elastic demand in modeling the TRNDP_Hasselstrom1981;Kocur and Hendrickson1982_.Van Nes et al._1988_applied a simultaneous distribution-modal split model based on transit deterrence for estimatingdemand for public transportation.In a series of studies,Chang and Schonfeld_1991,1993a,b_ and Spacovic et al._1994_estimated demand as a direct function of travel times and fares with respect to their elasticities,while Chien and Spacovic2001_,followed the same approach assuming that demand is additionally affected by headways,route spacing and fares.Finally, studies by Leblanc_1988_,Imam_1998_,Cipriani et al._2005_,Lee and Vuchic_2005_;and Fan and Machemehl_2006a_based demand estimation on mode choice models for estimating transit demand as a function of total demand for travel.中文译文:公交路线网络设计问题:回顾摘要:公共交通网络的有效设计让交通理论与实践成为众人关注的焦点,随之发展出了很多规划相关公交路线网络设计问题(TRNDP)的模型与方法。
20外文文献翻译原文及译文参考样式
20外⽂⽂献翻译原⽂及译⽂参考样式华北电⼒⼤学科技学院毕业设计(论⽂)附件外⽂⽂献翻译学号: 0819******** 姓名:宗鹏程所在系别:机械⼯程及⾃动化专业班级:机械08K1指导教师:张超原⽂标题:Development of a High-PerformanceMagnetic Gear年⽉⽇⾼性能磁齿轮的发展1摘要:本⽂提出了⼀个⾼性能永磁齿轮的计算和测量结果。
上述分析的永磁齿轮有5.5的传动⽐,并能够提供27 Nm的⼒矩。
分析表明,由于它的弹簧扭转常数很⼩,因此需要特别重视安装了这种⾼性能永磁齿轮的系统。
上述分析的齿轮也已经被应⽤在实际中,以验证、预测其效率。
经测量,由于较⼤端齿轮传动引起的磁⼒齿轮的扭矩只有16 Nm。
⼀项关于磁齿轮效率损失的系统研究也展⽰了为什么实际⼯作效率只有81%。
⼀⼤部分磁损耗起源于轴承,因为机械故障的存在,此轴承的备⽤轴承在此时是必要的。
如果没有源于轴的少量磁泄漏,我们估计能得到⾼达96%的效率。
与传统的机械齿轮的⽐较表明,磁性齿轮具有更好的效率和单位体积较⼤扭矩。
最后,可以得出结论,本⽂的研究结果可能有助于促进传统机械齿轮向磁性齿轮发展。
关键词:有限元分析(FEA)、变速箱,⾼转矩密度,磁性齿轮。
⼀、导⾔由于永久磁铁能产⽣磁通和磁⼒,虽然⼏个世纪过去了,许多⼈仍然着迷于永久磁铁。
,在过去20年的复兴阶段,正是这些优点已经使得永久磁铁在很多实际中⼴泛的应⽤,包括在起重机,扬声器,接头领域,尤其是在永久磁铁电机⽅⾯。
其中对永磁铁的复兴最常见于效率和转矩密度由于永磁铁的应⽤显著提⾼的⼩型机器的领域。
在永久磁铁没有获取⾼度重视的⼀个领域是传动装置的领域,也就是说,磁⼒联轴器不被⼴泛⽤于传动装置。
磁性联轴器基本上可以被视为以传动⽐为1:1磁⼒齿轮。
相⽐标准电⽓机器有约10kN m/m的扭矩,装有⾼能量永久磁铁的磁耦有⾮常⾼的单位体积密度的扭矩,变化范围⼤约300–400 kN 。
自动化专业毕业设计外文翻译--走进数字博物馆展览智能化:模块化的框架,艺术审美的超媒体
毕业设计(论文)外文文献翻译译文一:文献出处:Int J Digit Libr (2004) 4: 64–68/Digital Object Identifier (DOI)10.1007/s00799-003-0059-3走进数字博物馆展览智能化:模块化的框架,艺术审美的超媒体摘要在目前基于Web的超媒体环境下,建设和维持一个大规模的互动展览超媒体是一项艰巨的任务。
特别是编排风格繁多的多媒体创作,非常费时费力。
我们把发展智能数字博物馆展览系统作为第一步,本文提出了一种细粒度的模块化框架即分解一个典型的超媒体造型并将其介绍成细粒式模块(FGSM)。
一个基于“单声道媒体处理程序”的超媒体文档和一个数字博物馆展览管理框架已经被设计出来用以帮助我们理解FGSM的概念。
我们已经实施了基于Web的创作系统,允许内容提供商能够有效地构建起集媒体中心,互动性,美观于一体的超媒体网站。
今后,有关的优化和约束求解技术将用来最终实现数字博物馆智能展览的目标。
关键词:数字博物馆;展览;超媒体1.简介“博物馆是人们能够探索灵感,学习和享受的地方。
他们是机构收集,维护和访问,通过文物标本展现他们的社会。
”一个博物馆的基本任务包括收集,保存,研究和教育。
所有这些活动汇集在博物馆展览的公共展坛,目前这些都是博物馆对公众的主要吸引力。
同样,数字博物馆也是意料中必须建设的大型虚拟展览,实现高层次出席。
虚拟展览的主题基本上是一个编舞介绍数位典藏文物。
不论对身体还是虚拟博物馆展览的发展都是一个多学科的任务,通常需要观众专家,内容专家,通信专家和技术专家的积极参与。
由于参观者对博物馆的欣赏模式展览包括思考,理解,发现的相互作用,虚拟展览设计预计将超越只是提供单调平原网页的最终用户。
相反,考虑到美学展览需要提供先进的多媒体演示。
数字博物馆展览网站还必须考虑信息技术可用性优势,提高参与一个互动的个人设置。
然而,在当前基于Web的超媒体环境中,建设和维持一个大规模的吸引力展览的互动超媒体是复杂和困难的。
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毕业设计(论文)外文文献译文及原文学生:李树森学号:201006090217院(系):电气与信息工程学院专业:网络工程指导教师:王立梅2014年06月10日JSP的技术发展历史作者:Kathy Sierra and Bert Bates来源:Servlet&JSPJava Server Pages(JSP)是一种基于web的脚本编程技术,类似于网景公司的服务器端Java脚本语言—— server-side JavaScript(SSJS)和微软的Active Server Pages(ASP)。
与SSJS和ASP相比,JSP具有更好的可扩展性,并且它不专属于任何一家厂商或某一特定的Web服务器。
尽管JSP规范是由Sun 公司制定的,但任何厂商都可以在自己的系统上实现JSP。
在Sun正式发布JSP之后,这种新的Web应用开发技术很快引起了人们的关注。
JSP为创建高度动态的Web应用提供了一个独特的开发环境。
按照Sun的说法,JSP能够适应市场上包括Apache WebServer、IIS4.0在内的85%的服务器产品。
本文将介绍JSP相关的知识,以及JavaBean的相关内容,当然都是比较粗略的介绍其中的基本内容,仅仅起到抛砖引玉的作用,如果读者需要更详细的信息,请参考相应的JSP的书籍。
1.1 概述JSP(Java Server Pages)是由Sun Microsystems公司倡导、许多公司参与一起建立的一种动态网页技术标准,其在动态网页的建设中有其强大而特别的功能。
JSP与Microsoft的ASP技术非常相似。
两者都提供在HTML代码中混合某种程序代码、由语言引擎解释执行程序代码的能力。
下面我们简单的对它进行介绍。
JSP页面最终会转换成servlet。
因而,从根本上,JSP页面能够执行的任何任务都可以用servlet 来完成。
然而,这种底层的等同性并不意味着servlet和JSP页面对于所有的情况都等同适用。
问题不在于技术的能力,而是二者在便利性、生产率和可维护性上的不同。
毕竟,在特定平台上能够用Java 编程语言完成的事情,同样可以用汇编语言来完成,但是选择哪种语言依旧十分重要。
和单独使用servlet相比,JSP提供下述好处:JSP中HTML的编写与维护更为简单。
JSP中可以使用常规的HTML:没有额外的反斜杠,没有额外的双引号,也没有暗含的Java语法。
能够使用标准的网站开发工具。
即使是那些对JSP一无所知的HTML工具,我们也可以使用,因为它们会忽略JSP标签。
可以对开发团队进行划分。
Java程序员可以致力于动态代码。
Web开发人员可以将经理集中在表示层上。
对于大型的项目,这种划分极为重要。
依据开发团队的大小,及项目的复杂程度,可以对静态HTML和动态内容进行弱分离和强分离。
此处的讨论并不是说人们应该放弃使用servlet而仅仅使用JSP。
事实上,几乎所有的项目都会同时用到这两种技术。
在某些项目中,更适宜选用servlet,而针对项目中的某些请求,我们可能会在MVC构架下组合使用这两项技术。
我们总是希望用适当的工具完成相对应的工作,仅仅是servlet并不一定能够胜任所有工作。
1.2 JSP的由来Sun公司的JSP技术,使Web页面开发人员可以使用HTML或者XML标识来设计和格式化最终页面。
使用JSP标识或者小脚本来生成页面上的动态内容(内容是根据请求来变化的)。
Java Servlet是JSP技术的基础,而且大型的Web应用程序的开发需要Java Servlet和JSP配合才能完成,Servlet这个名称源于Applet,现在国内的翻译方式很多,本书为了避免误会,决定直接采用Servlet而不做任何翻译,读者如果愿意,可以称之为“小服务程序”。
Servlet其实和传统的CGI、ISAPI、NSAPI等Web程序开发工具的作用是相似的,在使用Java Servlet以后,用户不必再使用效率低下的CGI方式,也不必使用只能在某个固定Web服务器平台运行的API方式来动态生成Web页面。
许多Web服务器都支持Servlet,即使不直接支持Servlet的Web服务器也可以通过附加的应用服务器和模块来支持Servlet。
得益于Java的跨平台的特性,Servlet也是平台无关的,实际上,只要符合Java Servlet 规范,Servlet是完全与平台无关且是与服务器无关的。
由于Java Servlet内部是以线程方式提供服务,不必对于每个请求都启动一个进程,并且利用多线程机制可以同时为多个请求服务,因此Java ServleWebt效率非常高。
但Java Servlet也不是没有缺点,和传统的CGI、ISAPI、NSAPI方式相同,Java Servlet是利用输出HTML语句来实现动态网页的,如果用Java Servlet来开发整个网站,动态部分和静态页面的整合过程会非常难以实现。
为了解决Java Servlet的这种缺点,SUN推出了JSP。
许多年前,Marty受到邀请,参加一个有关软件技术的小型研讨会.坐在Marty旁边的人是James Gosling--- Java编程语言的发明者。
隔几个位置,是来自华盛顿一家大型软件公司的高级经理。
在讨论过程中,研讨会的主席提出了Jini的议题,这在当时是一项新的Java技术。
主席向该经理询问他的想法.他回答说,虽然现在言之过早,但这看起来会是非常有前途的一项技术。
他们会持续关注这项技术,如果这项技术变得流行起来,他们会遵循公司的“接受并扩充”的策略.此时, Gosling随意地插话说“你的意思其实就是不接受且不扩充。
”在此, Gosling的抱怨显示出,他感到这个公司会从其他公司那里拿走技术,用于他们自己的目的.出人意料的是,形势已经完全不同。
Java团队并没有发明这一思想----将页面设计成由静态HTML和用特殊标签标记的动态代码混合组成.。
ColdFusion多年前就已经这样做了。
甚至ASP(来自于前述经理所在公司的一项产品)都在JSP出现之前推广了这种方式。
实际上,JSP不只采用了这种通用概念,它甚至使用许多和ASP相同的特殊标签。
JSP是建立在Java servlets模型之上的表达层技术,它使编写HTML变得更简单。
像SSJS一样,它也允许你将静态HTML内容与服务器端脚本混合起来生成动态输出。
JSP把Java作为默认的脚本语言,然而,就像ASP可以使用其他语言(如JavaScript和VBScript)一样,JSP规范也允许使用其他语言。
1.3 JSP的特点按照脚本语言是服务于某一个子系统的语言这种论述,JSP应当被看作是一种脚本语言。
然而,作为一种脚本语言,JSP又显得过于强大了,在JSP中几乎可以使用全部的Java类。
作为一种基于文本的、以显示为中心的开发技术,JSP提供了Java Servlet的所有好处,并且,当与一个JavaBeans类结合在一起时,JSP提供了一种使内容和显示逻辑分开的简单方式。
分开内容和显示逻辑的好处是,更新页面外观的人员不必懂得Java代码,而更新JavaBeans类的人员也不必是设计网页的行家里手,就可以用带JavaBeans类的JSP页面来定义Web模板,以建立一个由具有相似的外观的页面组成的网站。
JavaBeans类完成数据提供,这样在模板中就没有Java代码,这意味着这些模板可以由一个HTML编写人员来维护。
当然,也可以利用Java Servlet来控制网站的逻辑,通过Java Servlet调用JSP文件的方式来将网站的逻辑和内容分离。
一般来说,在实际的JSP引擎中,JSP页面在执行时是编译式,而不是解释式的。
解释式的动态网页开发工具如ASP、PHP3等由于速度等原因已经满足不了当前大型电子商务应用的需要了,传统的开发技术都在向编译执行的方式改变,如ASP→ASP+;PHP3→PHP4。
在JSP规范书中,并没有明确要求JSP中的程序代码部分(称为Scriptlet)一定要用Java来写。
实际上,有一些JSP引擎就是采用的其他脚本语言,如EMAC-Script、WebL等,但实际上这几种脚本语言也是构建在Java上面,编译为Servlet来实现的。
按照JSP规范书写,和Java没有任何关系的Scriptlet 也是可以的,不过,由于JSP的强大功能主要在于能和JavaBeans、Enterprise JavaBeans共同运转,所以即使是Scriptlet部分不使用Java,编译成的执行代码也应该是与Java相关的。
1.4 JSP的机制要理解JSP怎样联合以上各种所提到的技术的优点,从而轻而易举地实现各种效果,用户必须首先了解“组件为中心的网页开发”和“页面为中心的网页开发”的区别。
SSJS和ASP都是在几年前推出的,那时网络还很年轻,没有人知道除了把所有的商务、数据和表达逻辑统统堆进原始网页中之外还有什么更好的解决方法。
这种以页面为中心的模型容易学习并且得到相当快速的发展。
然而,随着时间的推移,人们认识到这种方法不适于构建大型的、可升级的Web应用程序。
在脚本环境中书写的表达逻辑被锁在页面内,只有通过剪切和粘贴才能被重用。
表达逻辑通常和商务及数据逻辑混在一起,这使得当程序员试图改变一个应用程序的外观而不想破坏与之紧密结合的商务逻辑时,应用程序的维护就变得十分艰难。
其事实上,企业中可重用组件的应用早已经很成熟,没有人愿意为它们的应用程序重写那些逻辑。
HTML和图形设计师把它们的设计的实施工作交给了Web编写者,使他们不得不加倍工作——常常是手工编写,因为没有合适的工具可以把服务器端脚本与HTML内容结合起来。
简而言之,随着Web应用程序的复杂性不断提升,以页面为中心的开发方式的局限性变得明显起来。
与此同时,人们一直在寻找建立Web应用程序的更好方法,组件在客户机/服务器领域流行起来。
JavaBeans和ActiveX被“快速应用程序开发(RAD)工具”发行商推广给Java和Windows应用程序开发者用来快速开发复杂的程序。
这些技术使某领域内的专家可以为本领域内的垂直应用编写组件,而开发者可以直接拿来使用而不必掌握这一领域的专门技术。
作为一种以组件为中心的开发平台,JSP出现了。
它以JavaBeans和Enterprise JavaBeans(EJB)组件包含商务和数据逻辑的模型为基础,提供大量标签和一个脚本平台用来在HTML页中显示由JavaBeans产生或回送的内容。
由于JSP的以组件为中心的性质,它可以被Java和非Java开发者同样使用。
非Java开发者可以通过JSP的标签来使用高级Java开发者创建的JavaBeans。