文献翻译+原文
英文文献翻译
外文文献原稿和译文原稿Sodium Polyacrylate:Also known as super-absorbent or “SAP”(super absorbent polymer), Kimberly Clark used to call it SAM (super absorbent material). It is typically used in fine granular form (like table salt). It helps improve capacity for better retention in a disposable diaper, allowing the product to be thinner with improved performance and less usage of pine fluff pulp. The molecular structure of the polyacrylate has sodium carboxylate groups hanging off the main chain. When it comes in contact with water, the sodium detaches itself, leaving only carboxylions. Being negatively charged, these ions repel one another so that the polymer also has cross-links, which effectively leads to a three-dimensional structure. It has hige molecular weight of more than a million; thus, instead of getting dissolved, it solidifies into a gel. The Hydrogen in the water (H-O-H) is trapped by the acrylate due to the atomic bonds associated with the polarity forces between the atoms. Electrolytes in the liquid, such as salt minerals (urine contains 0.9% of minerals), reduce polarity, thereby affecting superabsorbent properties, especially with regard to the superabsorbent capacity for liquid retention. This is the main reason why diapers containing SAP should never be tested with plain water. Linear molecular configurations have less total capacity than non-linear molecules but, on the other hand, retention of liquid in a linear molecule is higher than in a non-linear molecule, due to improved polarity. For a list of SAP suppliers, please use this link: SAP, the superabsorbent can be designed to absorb higher amounts of liquids (with less retention) or very high retentions (but lower capacity). In addition, a surface cross linker can be added to the superabsorbent particle to help it move liquids while it is saturated. This helps avoid formation of "gel blocks", the phenomenon that describes the impossibility of moving liquids once a SAP particle gets saturated.History of Super Absorbent Polymer ChemistryUn til the 1980’s, water absorbing materials were cellulosic or fiber-based products. Choices were tissue paper, cotton, sponge, and fluff pulp. The water retention capacity of these types of materials is only 20 times their weight – at most.In the early 1960s, the United States Department of Agriculture (USDA) was conducting work on materials to improve water conservation in soils. They developed a resin based on the grafting of acrylonitrile polymer onto the backbone of starch molecules (i.e. starch-grafting). The hydrolyzed product of the hydrolysis of this starch-acrylonitrile co-polymer gave water absorption greater than 400 times its weight. Also, the gel did not release liquid water the way that fiber-based absorbents do.The polymer came to be known as “Super Slurper”.The USDA gave the technical know how several USA companies for further development of the basic technology. A wide range of grating combinations were attempted including work with acrylic acid, acrylamide and polyvinyl alcohol (PVA).Since Japanese companies were excluded by the USDA, they started independent research using starch, carboxy methyl cellulose (CMC), acrylic acid, polyvinyl alcohol (PVA) and isobutylene maleic anhydride (IMA).Early global participants in the development of super absorbent chemistry included Dow Chemical, Hercules, General Mills Chemical, DuPont, National Starch & Chemical, Enka (Akzo), Sanyo Chemical, Sumitomo Chemical, Kao, Nihon Starch and Japan Exlan.In the early 1970s, super absorbent polymer was used commercially for the first time –not for soil amendment applications as originally intended –but for disposable hygienic products. The first product markets were feminine sanitary napkins and adult incontinence products.In 1978, Park Davis (d.b.a. Professional Medical Products) used super absorbent polymers in sanitary napkins.Super absorbent polymer was first used in Europe in a baby diaper in 1982 when Schickendanz and Beghin-Say added the material to the absorbent core. Shortly thereafter, UniCharm introduced super absorbent baby diapers in Japan while Proctor & Gamble and Kimberly-Clark in the USA began to use the material.The development of super absorbent technology and performance has been largely led by demands in the disposable hygiene segment. Strides in absorption performance have allowed the development of the ultra-thin baby diaper which uses a fraction of the materials – particularly fluff pulp – which earlier disposable diapers consumed.Over the years, technology has progressed so that there is little if any starch-grafted super absorbent polymer used in disposable hygienic products. These super absorbents typically are cross-linked acrylic homo-polymers (usually Sodium neutralized).Super absorbents used in soil amendments applications tend to be cross-linked acrylic-acrylamide co-polymers (usually Potassium neutralized).Besides granular super absorbent polymers, ARCO Chemical developed a super absorbent fiber technology in the early 1990s. This technology was eventually sold to Camelot Absorbents. There are super absorbent fibers commercially available today. While significantly more expensive than the granular polymers, the super absorbent fibers offer technical advantages in certain niche markets including cable wrap, medical devices and food packaging.Sodium polyacrylate, also known as waterlock, is a polymer with the chemical formula [-CH2-CH(COONa)-]n widely used in consumer products. It has the ability to absorb as much as 200 to 300 times its mass in water. Acrylate polymers generally are considered to possess an anionic charge. While sodium neutralized polyacrylates are the most common form used in industry, there are also other salts available including potassium, lithium and ammonium.ApplicationsAcrylates and acrylic chemistry have a wide variety of industrial uses that include: ∙Sequestering agents in detergents. (By binding hard water elements such as calcium and magnesium, the surfactants in detergents work more efficiently.) ∙Thickening agents∙Coatings∙Fake snowSuper absorbent polymers. These cross-linked acrylic polymers are referred to as "Super Absorbents" and "Water Crystals", and are used in baby diapers. Copolymerversions are used in agriculture and other specialty absorbent applications. The origins of super absorbent polymer chemistry trace back to the early 1960s when the U.S. Department of Agriculture developed the first super absorbent polymer materials. This chemical is featured in the Maximum Absorbency Garment used by NASA.译文聚丙烯酸钠聚丙烯酸钠，又可以称为超级吸收剂或者又叫高吸水性树脂，凯博利克拉克教授曾经称它为SAM即：超级吸收性物质。
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。
文献翻译 译文+原文
09届本科毕业设计(论文)外文文献翻译学 院： 物理与电子工程学院专 业： 光电信息工程姓 名： 徐 驰学 号： Y05209222 外文出处： Surface & Coatings Technology214（2013）131-137附 件： 1.外文资料翻译译文；2.外文原文。
(用外文写)附件1：外文资料翻译译文气体温度通过PECVD沉积对Si：H薄膜的结构和光电性能的影响摘要气体温度的影响（TG）在等离子体增强化学气相沉积法（PECVD）生长的薄膜的结构和光电特性：H薄膜已使用多种表征技术研究。
气体的温度被确定为制备工艺的优化、结构和光电薄膜的性能改进的一个重要参数。
薄膜的结构性能进行了研究使用原子力显微镜（AFM），傅立叶变换红外光谱（FTIR），拉曼光谱，和电子自旋共振（ESR）。
此外，光谱椭偏仪（SE），在紫外线–可见光区域的光传输的测量和电气测量被用来研究的薄膜的光学和电学性能。
它被发现在Tg的变化可以修改的表面粗糙度，非晶网络秩序，氢键模式和薄膜的密度，并最终提高光学和电学性能。
1.介绍等离子体增强化学气相沉积法（PECVD）是氢化非晶硅薄膜制备一种技术，具有广泛的实际应用的重要材料。
它是用于太阳能电池生产，在夜视系统红外探测器，和薄膜晶体管的平板显示装置。
所有这些应用都是基于其良好的电气和光学特性以及与半导体技术兼容。
然而，根据a-Si的性质，PECVD制备H薄膜需要敏感的沉积条件，如衬底温度，功率密度，气体流量和压力。
许多努力已经花在制备高品质的薄膜具有较低的缺陷密度和较高的结构稳定性的H薄膜。
众所周知，衬底温度的强烈影响的自由基扩散的生长表面上，从而导致这些自由基更容易定位在最佳生长区。
因此，衬底温度一直是研究最多的沉积参数。
至于温度参数在PECVD工艺而言，除了衬底温度，气体温度（Tg）美联储在PECVD反应室在辉光放电是定制的a-Si的性能参数：H薄膜的新工艺。
英文文献整篇翻译
英文文献整篇翻译Title: The Impact of Climate Change on BiodiversityClimate change is a pressing issue that has significant impacts on biodiversity worldwide. Changes in temperature, precipitation patterns, and extreme weather events are altering ecosystems and threatening the survival of many species. The loss of biodiversity not only affects the natural world but also has implications for human societies.One of the major impacts of climate change onbiodiversity is the shifting of habitats. As temperatures rise, many species are forced to move to higher latitudesor elevations in search of suitable conditions. This can disrupt ecosystems and lead to the decline or extinction of species that are unable to adapt to the new conditions.In addition to habitat loss, climate change is also causing changes in the timing of biological events such as flowering, migration, and reproduction. These changes can disrupt the delicate balance of ecosystems and lead to mismatches between species that depend on each other for survival.Furthermore, climate change is exacerbating otherthreats to biodiversity such as habitat destruction, pollution, and overexploitation. The combination of these factors is putting immense pressure on many species and pushing them closer to extinction.It is essential that we take action to mitigate the impacts of climate change on biodiversity. This includes reducing greenhouse gas emissions, protecting and restoring habitats, and implementing conservation measures to safeguard vulnerable species. By addressing the root causes of climate change and protecting biodiversity, we canensure a sustainable future for both the natural world and human societies.气候变化对生物多样性的影响气候变化是一个紧迫的问题，对全球的生物多样性产生重大影响。
外文文献翻译(图片版)
本科毕业论文外文参考文献译文及原文学院经济与贸易学院专业经济学（贸易方向）年级班别2007级 1 班学号3207004154学生姓名欧阳倩指导教师童雪晖2010 年 6 月 3 日目录1 外文文献译文（一）中国银行业的改革和盈利能力（第1、2、4部分） (1)2 外文文献原文（一）CHINA’S BANKING REFORM AND PROFITABILITY（Part 1、2、4） (9)1概述世界银行（1997年）曾声称，中国的金融业是其经济的软肋。
当一国的经济增长的可持续性岌岌可危的时候，金融业的改革一直被认为是提高资金使用效率和消费型经济增长重新走向平衡的必要（Lardy，1998年，Prasad，2007年）。
事实上，不久前，中国的国有银行被视为“技术上破产”，它们的生存需要依靠充裕的国家流动资金。
但是，在银行改革开展以来，最近，强劲的盈利能力已恢复到国有商业银行的水平。
但自从中国的国有银行在不久之前已经走上了改革的道路，它可能过早宣布银行业的改革尚未取得完全的胜利。
此外，其坚实的财务表现虽然强劲，但不可持续增长。
随着经济增长在2008年全球经济衰退得带动下已经开始软化，银行预计将在一个比以前更加困难的经济形势下探索。
本文的目的不是要评价银行业改革对银行业绩的影响，这在一个完整的信贷周期后更好解决。
相反，我们的目标是通过审查改革的进展和银行改革战略，并分析其近期改革后的强劲的财务表现，但是这不能完全从迄今所进行的改革努力分离。
本文有三个部分。
在第二节中，我们回顾了中国的大型国有银行改革的战略，以及其执行情况，这是中国银行业改革的主要目标。
第三节中分析了2007年的财务表现集中在那些在市场上拥有浮动股份的四大国有商业银行：中国工商银行（工商银行），中国建设银行（建行），对中国银行（中银）和交通银行（交通银行）。
引人注目的是中国农业银行，它仍然处于重组上市过程中得适当时候的后期。
第四节总结一个对银行绩效评估。
外文文献翻译译稿和原文
外文文献翻译译稿1卡尔曼滤波的一个典型实例是从一组有限的，包含噪声的，通过对物体位置的观察序列（可能有偏差）预测出物体的位置的坐标及速度。
在很多工程应用（如雷达、计算机视觉）中都可以找到它的身影。
同时，卡尔曼滤波也是控制理论以及控制系统工程中的一个重要课题。
例如，对于雷达来说，人们感兴趣的是其能够跟踪目标。
但目标的位置、速度、加速度的测量值往往在任何时候都有噪声。
卡尔曼滤波利用目标的动态信息，设法去掉噪声的影响，得到一个关于目标位置的好的估计。
这个估计可以是对当前目标位置的估计（滤波），也可以是对于将来位置的估计（预测），也可以是对过去位置的估计（插值或平滑）。
命名[编辑]这种滤波方法以它的发明者鲁道夫.E.卡尔曼（Rudolph E. Kalman）命名，但是根据文献可知实际上Peter Swerling在更早之前就提出了一种类似的算法。
斯坦利。
施密特（Stanley Schmidt）首次实现了卡尔曼滤波器。
卡尔曼在NASA埃姆斯研究中心访问时，发现他的方法对于解决阿波罗计划的轨道预测很有用，后来阿波罗飞船的导航电脑便使用了这种滤波器。
关于这种滤波器的论文由Swerling（1958）、Kalman (1960)与Kalman and Bucy（1961）发表。
目前，卡尔曼滤波已经有很多不同的实现。
卡尔曼最初提出的形式现在一般称为简单卡尔曼滤波器。
除此以外，还有施密特扩展滤波器、信息滤波器以及很多Bierman, Thornton开发的平方根滤波器的变种。
也许最常见的卡尔曼滤波器是锁相环，它在收音机、计算机和几乎任何视频或通讯设备中广泛存在。
以下的讨论需要线性代数以及概率论的一般知识。
卡尔曼滤波建立在线性代数和隐马尔可夫模型（hidden Markov model）上。
其基本动态系统可以用一个马尔可夫链表示，该马尔可夫链建立在一个被高斯噪声（即正态分布的噪声）干扰的线性算子上的。
系统的状态可以用一个元素为实数的向量表示。
外文文献及翻译
外文文献及翻译1. 文献："The Effects of Exercise on Mental Health"翻译：运动对心理健康的影响Abstract: This article explores the effects of exercise on mental health. The author discusses various studies that have been conducted on this topic, and presents evidence to support the claim that exercise can have positive impacts on mental well-being. The article also examines the mechanisms through which exercise affects mental health, such as the release of endorphins and the reduction of stress hormones. Overall, the author concludes that exercise is an effective strategy for improving mental health and recommends incorporating physical activity into daily routines.摘要：本文探讨了运动对心理健康的影响。
作者讨论了在这个主题上进行的各种研究，并提出证据支持运动对心理健康有积极影响的观点。
该文章还探讨了运动如何影响心理健康的机制，如内啡肽的释放和压力激素的减少。
总的来说，作者得出结论，运动是改善心理健康的有效策略，并建议将体育活动纳入日常生活。
2. 文献： "The Benefits of Bilingualism"翻译：双语能力的好处Abstract: This paper examines the benefits of bilingualism. The author presents research findings that demonstrate the cognitiveadvantages of being bilingual, such as enhanced problem-solving skills and improved attention control. The article also explores the social and cultural benefits of bilingualism, such as increased cultural awareness and the ability to communicate with people from different backgrounds. Additionally, the author discusses the positive effects of bilingualism on mental health, highlighting its role in delaying the onset of cognitive decline and in providing a buffer against age-related memory loss. Overall, the author concludes that bilingualism offers a range of advantages and recommends promoting bilingual education and language learning. 摘要：本文研究了双语能力的好处。
外文文献翻译译稿
外文文献翻译译稿1可用性和期望值来自Willliam S.Green, Patrick W.Jordan.产品的愉悦：超越可用性根据人机工程学会（HFES）的观点，人机工程学着眼于“发现和共享可用于各种系统和设备设计的、关于人的特点的知识”。
人们通常只是把它作为生物力学和人体测量所关注的内容，实际上它是从更广泛的意义上的一种对人（产品用户）的全面和综合的理解。
HFES从二战中有军方从事的系统分析中发展而来。
其中的三种主要研究的是人体测量、复杂信息的解释和管理，以及在部队和装备调配中应用的系统分析。
系统分析在尺度和复杂性方面跨度很大，大的系统分析有类似于诺曼底登陆准备的大型系统规划，小到去理解如何从合理性和规模的角度才最佳的布置和装备人员。
诺曼底登陆是20世纪最复杂的事件之一。
他要求建立一个在战斗开始之前还不确定的庞大的人员和物资的合理分配系统。
在更小的规模上，装备和军事人物的布置意味着如何去组织、训练和安排战士，最大限度的发挥他们的长处。
士兵必须迅速地接受训练，并且能够有效地使用和维护在二战中发展起来的一系列技术装备。
其中，对于飞行员、潜艇人员和坦克驾驶员有神采的限制。
复杂的新装备的开发要求找到最好的税收、密码便医院、破译人员、雷达和声纳操作员、轰炸机驾驶员和机组人员。
在战后，随着公司及其产品在尺度、领域和复杂性方面的增长，很多系统分析人员在商用领域找到了发展机会。
尽管是战后的发展才导致了1957年人机工程协会（HFES）的建立，但人机研究的起源可以追溯到大批量生产方式的成型阶段，是当时提高生产效率的要求。
随着工作方式从手工生产和农业生产中的转移，新的工厂工作的概念逐步发展起来。
福特的流水生产线和泰勒的效率理论开始对生产的规划和教育产生影响。
即使在家庭生活中，妇女们也开始接受了现代家庭管理理论，并运用这些理论来组织和规划家庭。
在20世纪末，一种涵盖面更广的人机工程正在发展之中。
新的人机工程学是为了适应已经被广泛意识到的对用户行为模式更深入的需求而诞生的，它开始应用定型研究方法，并探索人的情感和认知因素。
英文文献全文翻译
英文文献全文翻译全文共四篇示例，供读者参考第一篇示例：LeGuin, Ursula K. (December 18, 2002). "Dancing at the Edge of the World: Thoughts on Words, Women, Places".《世界边缘的舞蹈：关于语言、女性和地方的思考》Introduction:In "Dancing at the Edge of the World," Ursula K. LeGuin explores the intersection of language, women, and places. She writes about the power of words, the role of women in society, and the importance of our connection to the places we inhabit. Through a series of essays, LeGuin invites readers to think critically about these topics and consider how they shape our understanding of the world.Chapter 1: LanguageConclusion:第二篇示例：IntroductionEnglish literature translation is an important field in the study of language and culture. The translation of English literature involves not only the linguistic translation of words or sentences but also the transfer of cultural meaning and emotional resonance. This article will discuss the challenges and techniques of translating English literature, as well as the importance of preserving the original author's voice and style in the translated text.Challenges in translating English literature第三篇示例：Title: The Importance of Translation of Full English TextsTranslation plays a crucial role in bringing different languages and cultures together. More specifically, translating full English texts into different languages allows for access to valuable information and insights that may otherwise be inaccessible to those who do not speak English. In this article, we will explore the importance of translating full English texts and the benefits it brings.第四篇示例：Abstract: This article discusses the importance of translating English literature and the challenges translators face when putting together a full-text translation. It highlights the skills and knowledge needed to accurately convey the meaning and tone of the original text while preserving its cultural and literary nuances. Through a detailed analysis of the translation process, this article emphasizes the crucial role translators play in bridging the gap between languages and making English literature accessible to a global audience.IntroductionEnglish literature is a rich and diverse field encompassing a wide range of genres, styles, and themes. From classic works by Shakespeare and Dickens to contemporary novels by authors like J.K. Rowling and Philip Pullman, English literature offers something for everyone. However, for non-English speakers, accessing and understanding these works can be a challenge. This is where translation comes in.Translation is the process of rendering a text from one language into another, while striving to preserve the original meaning, tone, and style of the original work. Translating afull-length English text requires a deep understanding of both languages, as well as a keen awareness of the cultural andhistorical context in which the work was written. Additionally, translators must possess strong writing skills in order to convey the beauty and complexity of the original text in a new language.Challenges of Full-text TranslationTranslating a full-length English text poses several challenges for translators. One of the most significant challenges is capturing the nuances and subtleties of the original work. English literature is known for its rich and layered language, with intricate wordplay, metaphors, and symbolism that can be difficult to convey in another language. Translators must carefully consider each word and phrase in order to accurately convey the author's intended meaning.Another challenge of full-text translation is maintaining the author's unique voice and style. Each writer has a distinct way of expressing themselves, and a good translator must be able to replicate this voice in the translated text. This requires a deep understanding of the author's writing style, as well as the ability to adapt it to the conventions of the target language.Additionally, translators must be mindful of the cultural and historical context of the original work. English literature is deeply rooted in the history and traditions of the English-speaking world, and translators must be aware of these influences in orderto accurately convey the author's intended message. This requires thorough research and a nuanced understanding of the social, political, and economic factors that shaped the work.Skills and Knowledge RequiredTo successfully translate a full-length English text, translators must possess a wide range of skills and knowledge. First and foremost, translators must be fluent in both the source language (English) and the target language. This includes a strong grasp of grammar, syntax, and vocabulary in both languages, as well as an understanding of the cultural and historical context of the works being translated.Translators must also have a keen eye for detail and a meticulous approach to their work. Every word, sentence, and paragraph must be carefully considered and translated with precision in order to accurately convey the meaning of the original text. This requires strong analytical skills and a deep understanding of the nuances and complexities of language.Furthermore, translators must possess strong writing skills in order to craft a compelling and engaging translation. Translating a full-length English text is not simply a matter of substituting one word for another; it requires creativity, imagination, and a deep appreciation for the beauty of language. Translators mustbe able to capture the rhythm, cadence, and tone of the original work in their translation, while also adapting it to the conventions of the target language.ConclusionIn conclusion, translating a full-length English text is a complex and challenging task that requires a high level of skill, knowledge, and creativity. Translators must possess a deep understanding of both the source and target languages, as well as the cultural and historical context of the work being translated. Through their careful and meticulous work, translators play a crucial role in making English literature accessible to a global audience, bridging the gap between languages and cultures. By preserving the beauty and complexity of the original text in their translations, translators enrich our understanding of literature and bring the works of English authors to readers around the world.。
论文外文文献翻译
论文外文文献翻译以下是一篇700字左右的论文外文文献翻译：原文题目：The Role of Artificial Intelligence in Medical Diagnostics: A Review原文摘要：In recent years, there has been a growing interest in the use of artificial intelligence (AI) in the field of medical diagnostics. AI has the potential to improve the accuracy and efficiency of medical diagnoses, and can assist clinicians in making treatment decisions. This review aims to examine the current state of AI in medical diagnostics, and discuss its advantages and limitations. Several AI techniques, including machine learning, deep learning, and natural language processing, are discussed. The review also examines the ethical and legal considerations associated with the use of AI in medical diagnostics. Overall, AI has shown great promise in improving medical diagnostics, but further research is needed to fully understand its potential benefits and limitations.AI在医学诊断中发挥的作用：一项综述近年来，人工智能（AI）在医学诊断领域的应用引起了越来越多的关注。
外文文献翻译酒店服务质量管理
毕设附件外文文献翻译原文及译文（3500 字）原文Study of Service Quality Management in Hotel IndustryBorkar；SameerAbstractIt is an attempt to understand the role of quality improvement process in hospitality industry and effectiveness in making it sustainable business enterprise. It is a survey of the presently adopted quality management tools which are making the hotels operations better focused and reliable and meet the customer expectations。
Descriptive research design is used to know the parameters of service quality management in hospitality industry。
Exploratory research design is undertaken to dig out the service quality management practices and its effectiveness. Data analysis is done and presented；hypothesis is tested against the collected data. Since the industry continuously tries to improve upon their services to meet the levels of customer satisfaction; Study presents tools for continuous improvement process and how it benefits all the stake holders。
英文文献翻译
外文翻译（原文）Catalytic wet peroxide oxidation of azo dye (Congo red) using modified Y zeolite as catalystAbstractThe present study explores the degradation of azo dye (Congo red) by catalytic wet peroxide oxidation using Fe exchanged commercial Y zeolite as a catalyst. The effects of various operating parameters like temperature, initial pH, hydrogen peroxide concentration and catalyst loading on the removal of dye,color and COD from an aqueous solution were studied at atmospheric pressure. The percent removals of dye, color and COD at optimum pH07, 90◦C using 0.6 ml H 2 O2/350 ml solution and 1 g/l catalyst was 97% (in 4 h), 100% (in 45 min) and 58% (in 4 h), respectively. The % dye removal has been found to be less in comparison to % color removal at all conditions, e.g. dye removal in 45 min and at above conditions was 82%, whereas the color removal was 100%. The results indicate that the Fe exchanged Y zeolite is a promising catalyst for dye removal. Fe exchanged catalyst is characterized using XRD, SEM/EDAX, surface area analyzer and FTIR. Though the dye, color and COD removals were maximum at pH02 but as the leaching of Fe from the catalyst was more in acidic pH range, pH0 7 was taken as operating pH due to almost comparable removals as of pH0 2 and no leaching of Fe ions.© 2008 Elsevier B.V. All rights reserved.1. IntroductionReactive azo dyes from textile and dyeing industries pose grave environmental problem. An estimate shows that textiles account for 14% of India’s industrial production and around 27% of its export earnings[1]. Production during 2006 registered a growth of about 3.5% at 29,500 tonnes and the textile industry accounts for the largest consumption of dyestuffs at nearly 80% [2]. The waste containing these azo dyes is non-degradable. The process of dyeing is a combination of bleaching and coloring, which generates huge quantities of wastewaters causing environmental problems. The effluents from these industries consist of large quantities of sodium, chloride, sulphate, hardness, carcinogenic dye ingredients and total dissolved solids with very high BOD and COD values over 1500 mg/l and over 5000 mg/l, respectively [3]. Various methods have been used for dye removal like adsorption, coagulation, electrocoagulation, Fenton’s reagent and combination of these processes. Though these treatment processes are efficient in dye removal, they generate adsorbed waste/sludge, etc. which further causes a secondary pollution. In wet oxidation the sludge is disposed off to a great extent by oxidizing the organic pollutant. Catalytic wet oxidation method (CWAO and CWPO) is gaining more popularity. CWPO process using H2O2, in particular has advantages like better oxidation ability thanusing oxygen,as the former is carried out at lower pressure (atmospheric pres-sure).WAO usually acts under high temperatures (200–325◦C)and pressure (50–150 bar). A comparable oxidation efficiency is obtained at a less temperature of 100–120◦C when using hydrogen peroxide as the oxi dizing agent instead of oxygen [4].WAO is capital intensive whereas WPO needs limited capital but generates little higher running costs [4].Rivas et al.[5] showed that the addition of H2O2(as a source of free radicals) enhanced wet air oxidation of phenol, a highly non-degradable substance and found that the combined addition of H2O2 and a bivalent metal (i.e. Cu, Co or Mn) enhanced the rate of phenol removal. Various oxidation catalysts have been studied for the removal of different compounds like phenol, benzoic acid, dyes, etc. by CWPO process. Catalysts like Fe2O3/CeO2and WO3/CeO2 in the removal of phenolic solution, (Al–Fe) pillared clay named FAZA in the removal of 4-hydroxy benzoic acid, mixed (Al–Fe) pillared clays in the removal of organic compounds have been used[6–8] .Removal of dyes by CWPO process is gaining importance in recent times with a large number of catalysts. Kim and Lee [9] used Cu/Al2O3 and copper plate in treatment of dye house effluents. Liu and Sun [10] removed acid orange 52, acid orange 7 and reactive black 5 using CeO2doped Fe2O3/ -Al2O3 from dye waste water. Kim and Lee [11] reported the treatment of reactive dye solutions by using Al–Cu pillared clays as catalyst.Among these catalysts, modified zeolites are preferred for improved efficiency, lower by-product formation and less severe experimental conditions (temperatures and pressures). Theimproved efficiency of the catalyst is ascribed to its structure and large surface area with the ability of forming complex compounds. Zeolites can be ion exchanged using transition metal ions like Fe,Cu, Mn and others like Ca, Ba, etc. Zeolites are negatively charged because of the substitution of Si(IV) by Al(III) in the tetrahedral accounts for a negative charge of the structure and hence the Si/Al ratio determines the properties of zeolites like ion exchange capacity [12] . These metal ions neutralizethe negative charge on zeolites and their position, size and number determine the properties of zeolite. These metal ions are fixed to the rigid zeolite framework which prevents leaching and precipitation in various reactions[13–21] .In this work, catalytic wet peroxide oxidation of Congo red azo dye using Fe exchanged Y zeolite has been presented. Effect of variables like temperature, initial pH, peroxide concentration and catalyst loading on catalytic wet peroxide oxidation were examined and the optimum conditions evaluated.2.Materials and methods2.1. ChemicalsHydrogen peroxide (30% analytical grade), manganese dioxide,sodium hydroxide pellets (AR) and hydrochloric acid were obtained from RFCL limited (Mumbai), India. Congo red was obtained from Loba Chemie Pvt. Ltd. (Mumbai) and were obtained from RFCL limited (Mumbai), India.Commercial Na–Y zeolite was obtained from Sud chemie Pvt.Ltd. (Baroda), India. Commercial catalyst was iron exchanged with excess 1 M Fe(NO3)3 at 80◦C for 6 h. The process was repeated three times and the sample was thoroughly washed with distilled water and dried in oven in air at60◦C for 10-12 h. The amount of iron exchanged was 1.53 wt% estimated by A.A.S.2.2. Apparatus and procedureThe experimental studies were carried out in a 0.5 l three-necked glass reactor equipped with a magnetic stirrer with heater and a total reflux (Fig. 13). Water containing Congo red dye was transferred to the three-necked glass reactor. Thereafter, the catalyst was added to the solution. The temperature of the reaction mixture was raised using heater to the desired value and maintained by a P.I.D. temperature controller, which was fitted in one of the necks through the thermocouple. The raising of the temperature of the reaction mixture to 90◦C from ambient took about 30 min.The total reflux prevents any loss of vapor and magnetic stirrer to agitate the mixture. Hydrogen peroxide was added, the runs were conducted at 90◦C and the samples were taken at periodic intervals. The samples after collection were raised to pH-11 by adding 0.1N NaOH (so that no further reaction takes place) and the residual hydrogen peroxide was removed by adding MnO2 which catalyzed the decomposition of peroxide to water and oxygen. The samples were allowed to settle for overnight or one day (or centrifuged) and filtered. The supernatant was tested for color and COD. After the completion of the run, the mixture was allowed to cool and settle overnight.2.3. CharacterizationThe determination of structure of the heterogeneous catalyst was done by X-ray diffractometer (Bruker AXS, Diffraktometer D8,Germany). The catalyst structure was confirm ed by using Cu Kα as a source and Ni as a filter. Goniometer speed was kept at 1cm/min and the chart speed was 1 cm/min. The range of scanning angle(2θ) was kept at 3–60◦. The intensity peaks indicate the values of2θ , where Bragg’s law is applicable. The formation of compounds was tested by comparing the XRD patternusing JCPDS files (1971).The determination of images and composition of catalyst were done by SEM/EDAX QUANTA 200 FEG. Scanning for zeolite samples was taken at various magnifications and voltage to account for the crystal structure and size. From EDAX, the composition of the elements in weight percentage and atomic percentage were obtained along with the spectra for overall compositions and particular local area compositions. BET surface area of the samples was analyzed by Micromeritics CHEMISORB 2720. The FTIR spectra of the catalyst was recorded on a FTIR Spectrometer (Thermo Nicolet, USA, Software used: NEXUS) in the 4000–480 cm−1wave number range using KBr pellets. The internal tetrahedra and external linkage of the zeolites formed are identified and confirmed by FTIR. The IR spectra data in Table 2 is taken from literature[22] .2.4. AnalysisThe amount of the dye present in the solution was analyzed by direct reading TVS 25 (A) Visible Spectrophotometer. The visible range absorbance at the characteristic wavelength of the sample at 497 nm was recorded to follow the progress of decolorization during wet peroxide oxidation.The COD of the dye solution was estimated by the Standard Dichromator Closed Reflux Method (APHA-1989) using a COD analyzer (Aqualytic, Germany). The color in Pt–Co unit was estimated using a color meter (Hanna HI93727, Hanna Instruments, Singapore) at 470 nm and the pH was measured using a Thermo Orion, USA make pH meter. The treated dye solutions were centrifuged (Model R24, Remi Instruments Pvt. Ltd., Mumbai, India) to obtain the supernatant free of solid MnO2.A.A.S (Avanta GBC, Australia) was used to find the amount of iron exchanged and leached.3. Results and discussionDue to the iron present after the exchange process, the Y peaks diminished along with the rise in Fe peaks. Similar phenomena has also been observed by Yee and Yaacob [23] who obtained zeolite iron oxide by adding NaOH and H2O2(drop wise) at 60◦C to Na–Y zeolite. XRD pattern ( Fig. 2) showed diminishing zeolite peaks along with evolution of peaks corresponding to y-Fe2O3 with increasing NaOH concentration. The IR assignments from FTIR (Fig. 3) remain satisfied even after iron exchanging. The EDAX data (Table 1) show clearly an increase in the value of Fe conc. after ion exchange of Y-zeolite. The BET surface area (Table 1) has been found to decrease from 433 to 423 m2/g after Fe exchange. SEM image is shown in Fig. 1 . Table 2 presents FTIR specifications of zeolites (common to all zeolites).The effect of temperature, initial pH, hydrogen peroxide concentration and catalyst loading on catalytic wet peroxide oxidation of azo dye Congo red were investigated in detail.Fig. 1. SEM image of Fe-exchanged Y zeolite.Fig. 2. XRD of commercial and Fe-exchanged commercial Y zeolite.BET surface area (commercial Na–Y): 433.4 m2/g.BET surface area (Fe exchanged commercial Na–Y): 423 m2/g.Table 2Zeolite IR assignments (common for all zeolites) from FTIR.3.1. Effect of temperature on dye, color and COD removalThe temperatures during the experiments were varied from50◦Cto100◦C. A maximum conversion of dye of 99.1% was observed at 100◦C in 4 h (and 97% at 90◦C). The dye rem ovals at 80◦C, 70◦C, 60◦C and 50◦C and at 4 h are 56%, 52%, 42% and 30%,respectively. Fig. 4 shows that at a particular temperature, the dye concentration gradually decreases with time. The initial red color of the dye solution decreased into brown color in due course and finally the brown color disappeared into a colorless solution. Dye concentration decreases at faster rates with temperatures for initial 30 min and thereafter it decreases from 1 h to 2 h. The initial concentrations of dye did not change after a brief contact period of dye solution with the Fe-exchanged zeolite catalyst (before CWPO)confirming that there is negligible adsorption of the dye by the catalyst.Fig. 5 shows the results obtained for color removal as a function of time and temperature. The maximum color removal (100%) is obtained at 100◦C in 30 min and also at 90◦C in 45 min. At a particular temperature, the color continuously decreases with time atFig. 3. FTIR of Fe-exchanged Y zeolite.Fig. 4. % dye removal as function of temperature.faster rate in first few minutes until a certain point ( t = 45 min) and then remaining almost unchanged. At 50◦C, the color removal is very low, whereas at 60◦C, there is a sudden shift towards its greater removal. The color removal is much higher at higher temperatures(70–100◦C).Fig. 6 depicts the results obtained for %COD removal as a function of time and temperature. A maximum COD removal of 66% was obtained at 100◦C (at 4 h) followed by 58% at 90◦C (at 4 h). Until60◦C, the rate of COD removal is less and during 70–100◦C, the rate is much faster.3.2. Effect of initial pH on dye, color and COD removalThe influence of initial pH on dye (Congo red) removal was studied at different pH (pH0 2, 4, 7, 8, 9 and 11) without any adjustment of pH during the experiments. A maximum conversion of 99% was obtained at pH0 2 followed by 97% at pH0 7. The dye removal at pH0 4, 8, 9 and 11 were 94%, 29%, 5% and 0.6%, respectively. All the runs were conducted for 4 h duration. The color of the solution is violet blue at pH0 2 (a colloidal solution) and greenish blue at pH0 4 (colloidal solution). In neutral and basic pH0(7, 8, 9 and 11) range, color of the solution did not change during treatment and was same as original solution, i.e. red color. Fe cations can leach out from zeolite structure into the solution causing secondary pollution. Leaching of Fe cations out of zeolitesFig. 5. % color removal as function of temperature.Fig. 6. %COD removal as function of temperature.Fig. 7. % color removal as function of pH0depends strongly on pH of the solution. The leaching of iron ions was enhanced at low pH values [24,25] . In order to determine dissolved Fe concentration, final pH values of the solutions were analyzed by A.A.S. At initial pH0 2 and 4, Fe detected in the solution was 7.8 ppm and 3.9 ppm, respectively. At pH0 7 and in alkaline range, there wasFig. 8. %COD removal as function of pH0.Fig. 9. % color removal as function of peroxide concentration.Fig. 10. %COD removal as function of peroxide concentration.almost no leaching. pH0 7, therefore, was chosen to be optimum pH for future experiments. The final pH values pH f after the reaction corresponding to pH0 2, 4, 6, 8, 9 and 11 were 2.1, 4.2, 7.2, 7.7 and 8.7, respectively. This show that the pH f tend to reach to neutral pH for all starting pH values.Fig. 7 presents the results obtained for color removal as a function of time and pH0. A maximum color removal of 100% was obtained at pH0 2 (in 10 min) and also at pH0 7 (in 45 min). The color removal at a particular pH0 decreases at a faster rateinitially (0–1 h) and thereafter it has a slower rate. The lowest removal was observed at pH0 11 with almost no removal.Fig. 11. % color removal as function of catalyst loading.Fig. 12. %COD removal as function of catalyst loading.The results obtained for COD removal as a function of time and pH0 are shown in Fig. 8 . A maximum COD removal of 69% was obtained at pH0 2 in 4 h followed by 63% at pH0 4 and 58% at pH0 7in4h.Fig. 8 shows maximum decrease in COD value in the initial 30 mines at all pH0. The decrease in COD is not appreciable thereafter. The COD removal is more in acidic range with a maximum removal of 69%, moderate in neutral region and least in basic region.3.3. Effect of peroxide concentration on dye, color and COD removalThe influence of H2O2 concentration on dye removal was investigated at different concentrations of hydrogen peroxide (in the range 0–6 ml). A maximum removal of 99.02% was obtained at H2O2 concentration of 3 ml per 350 ml of solution, followed by 98.3% at 1ml and 97% at 0.6 ml. The dye removal at H2O2concentrations of 6 ml,0.3 ml and 0 ml (and at 4 h) were 94%, 82% and 8%, respectively. The dye removal rate at 90◦C temperature is gradual at all conc entrations of peroxide. At peroxide concentration of 0 ml, there is very little removal of dye, hardly 8%. Hence, it can be inferred that catalytic thermolysis (a process of effluent treatment by heating the effluent with/without catalyst) is not active and cannot be applied for dye removal.At the beginning of the reaction, the OH•radicals which are produced additionally when peroxide concentration is increased,speeds up the azo dye degradation. After a particular peroxide concentration, on further increase of the peroxide, the dye removal isFig. 13. Schematic diagram of the reactor.not increased. This may be because of the presence of excess peroxide concentration, hydroperoxyl radicals (HO2•) are produced from hydroxyl radicals that are already formed. The hydroperoxyl radicals do not contribute to the oxidative degradation of the organic substrate and are much less reactive. The degradation of the organic substrate occurs only by reaction with HO•[26] .The % color removal at a particular peroxide concentration increases at a faster rate in the initial 45 min and then at slower rates afterwards (Fig. 9). As H2O2 concentration increases, the rate of removal is much faster, reaching 100% in 45 minusing 6 ml H2O2 per 350 ml solution, whereas it is 100% in 1 h for both 0.3 ml and3ml.Fig. 10 shows the results obtained for COD removal as a function of time and H2O2 concentration. The maximum COD removal, 63% is obtained for H2O2 conc. 3 ml at 90◦C, pH0 7 and 2 h duration.3.4. Effect of catalyst loading on dye, color and COD removalThe influence of catalyst concentration on dye removal was investigated at different concentrations (in the range 0.5–1.5 g/l). A maximum dye removal of 98.6% was observed at 1.5 g/l followed by 98.3% at 1 g/l and 87.3% at 0.5 g/l in 4 h duration. The % dye removal without catalyst was very low with only 36% dye removal in 4 h. By comparing the results for the dye removal without catalyst and1.5 g/l catalyst, the removal for 1.5 g/l is approximately three times to that of without catalyst. The rate of removal is also more for higher concentrations of catalyst and increases with it.Fig. 11 shows the results obtained for color removal as a function of time and catalyst concentration. The maximum color removal of 100% was obtained using 1.5 g/l catalyst conc. in 1.5 h and also using 1 g/l catalyst in 3 h.Fig. 12 presents the results obtained for %COD removal as a function of time and catalyst concentration. A maximum COD removal of 58% was obtained at catalyst conc. 1 g/l, 51.8% at 1.5 g/l and 50.5% at 0.5 g/l in 4 h. Without catalyst, the COD removal was only 35%.4. ConclusionsThe % removals of dye, color and COD by catalytic wet peroxide oxidation obtained at 100◦C, 4 h duration using 0.6 ml H2O2/350 ml solution, 1 g/l Fe–Y catalyst and pH0 7 were 99.1%, 100% (30 min)and 66%, respectively. As at 100◦C the solution has tendency to vaporize during the operation, 90◦C was taken as operating temperature. The corresponding % removals at 90◦C were 97% dy e, 100%color (in 45 min) and 58% COD. Acidic range gave higher % removals in comparison to neutral and alkaline range. At pH0 2, the dye, color and COD removals of 99%,100% (in 10 min) and 69% were observed after 4 h duration. As at pH0 2, the leaching of Fe ions from Y zeolite catalyst is predominant,pH0 7 was taken as operating pH. Fe concentration of 7.8 ppm was observed in the solution at pH0 2. The values of removals, however,are comparable to pH0 2, with dye removal of 97%, color removal of100% (in 45 min) and COD removal of 58% in 4 h.The H2O2concentration was found to be optimum at 3 ml/350 ml solution giving dye, color and COD removals of 99%,100% (in 1 h) and 63%, respectively.The study on the effect of catalyst loading revealed 1.5 g/l as best among the catalyst concentrations studied. The results with 1 g/l and 1.5 g/l catalyst concentration were almost comparable.外文翻译（译文）使用改性Y沸石为催化剂湿式催化过氧化氢氧化偶氮染料(刚果红)摘要本研究主要探讨了使用改性Y沸石固载铁离子作为催化剂湿式催化过氧化氢氧化降解偶氮染料(刚果红)。
翻译文献英文原文
NET-BASED TASK MANAGEMENT SYSTEMHector Garcia-Molina, Jeffrey D. Ullman, Jennifer WisdomABSTRACTIn net-based collaborative design environment, design resources become more and more varied and complex. Besides common information management systems, design resources can be organized in connection with design activities.A set of activities and resources linked by logic relations can form a task. A task has at least one objective and can be broken down into smaller ones. So a design project can be separated into many subtasks forming a hierarchical structure.Task Management System (TMS) is designed to break down these tasks and assign certain resources to its task nodes．As a result of decomposition.al1 design resources and activities could be managed via this system.KEY WORDS：Collaborative Design, Task Management System (TMS), Task Decomposition, Information Management System1 IntroductionAlong with the rapid upgrade of request for advanced design methods, more and more design tool appeared to support new design methods and forms. Design in a web environment with multi-partners being involved requires a more powerful and efficient management system .Design partners can be located everywhere over the net with their own organizations. They could be mutually independent experts or teams of tens of employees. This article discusses a task management system (TMS) which manages design activities and resources by breaking down design objectives and re-organizing design resources in connection with the activities. Comparing with common information management systems (IMS) like product data management system and document management system, TMS can manage the whole design process. It has two tiers which make it much more f1exible in structure.The lower tier consists of traditional common IMSS and the upper one fulfills logic activity management through controlling a tree-like structure, allocating design resources and makingdecisions about how to carry out a design project. Its functioning paradigm varies in different projects depending on the project’s scale and purpose. As a result of this structure, TMS can separate its data model from its logic mode1.It could bring about structure optimization and efficiency improvement, especially in a large scale project.2 Task Management in Net-Based Collaborative Design Environment2.1 Evolution of the Design EnvironmentDuring a net-based collaborative design process, designers transform their working environment from a single PC desktop to LAN, and even extend to WAN. Each design partner can be a single expert or a combination of many teams of several subjects, even if they are far away from each other geographically. In the net-based collaborative design environment, people from every terminal of the net can exchange their information interactively with each other and send data to authorized roles via their design tools. The Co Design Space is such an environment which provides a set of these tools to help design partners communicate and obtain design information. Code sign Space aims at improving the efficiency of collaborative work, making enterprises increase its sensitivity to markets and optimize the configuration of resource.2.2 Management of Resources and Activities in Net-Based Collaborative EnvironmentThe expansion of design environment also caused a new problem of how to organize the resources and design activities in that environment. As the number of design partners increases, resources also increase in direct proportion. But relations between resources increase in square ratio. To organize these resources and their relations needs an integrated management system which can recognize them and provide to designers in case of they are needed.One solution is to use special information management system (IMS).An IMS can provide database, file systems and in/out interfaces to manage a given resource. For example there are several IMS tools in Co Design Space such as Product Data Management System, Document Management System and so on. These systems can provide its special information which design users want.But the structure of design activities is much more complicated than these IM S could manage, because even a simple design project may involve different design resources such asdocuments, drafts and equipments. Not only product data or documents, design activities also need the support of organizations in design processes. This article puts forward a new design system which attempts to integrate different resources into the related design activities. That is task management system (TMS).3 Task Breakdown Model3.1 Basis of Task BreakdownWhen people set out to accomplish a project, they usually separate it into a sequence of tasks and finish them one by one. Each design project can be regarded as an aggregate of activities, roles and data. Here we define a task as a set of activities and resources and also having at least one objective. Because large tasks can be separated into small ones, if we separate a project target into several lower—level objectives, we define that the project is broken down into subtasks and each objective maps to a subtask. Obviously if each subtask is accomplished, the project is surely finished. So TMS integrates design activities and resources through planning these tasks.Net-based collaborative design mostly aims at products development. Project managers (PM) assign subtasks to designers or design teams who may locate in other cities. The designers and teams execute their own tasks under the constraints which are defined by the PM and negotiated with each other via the collaborative design environment. So the designers and teams are independent collaborative partners and have incompact coupling relationships. They are driven together only by theft design tasks. After the PM have finished decomposing the project, each designer or team leader who has been assigned with a subtask become a 1ow-class PM of his own task. And he can do the same thing as his PM done to him, re-breaking down and re-assigning tasks.So we put forward two rules for Task Breakdown in a net-based environment, incompact coupling and object-driven. Incompact coupling means the less relationship between two tasks. When two subtasks were coupled too tightly, the requirement for communication between their designers will increase a lot. Too much communication wil1 not only waste time and reduce efficiency, but also bring errors. It will become much more difficult to manage project process than usually in this situation. On the other hand every task has its own objective. From the view point of PM of a superior task each subtask could be a black box and how to execute these subtasks is unknown. The PM concerns only the results and constraints of these subtasks, and may never concern what will happen inside it.3.2 Task Breakdown MethodAccording to the above basis, a project can be separated into several subtasks. And when this separating continues, it will finally be decomposed into a task tree. Except the root of the tree is a project, all eaves and branches are subtasks. Since a design project can be separated into a task tree, all its resources can be added to it depending on their relationship. For example, a Small-Sized-Satellite.Design (3SD) project can be broken down into two design objectives as Satellite Hardware. Design (SHD) and Satellite-Software-Exploit (SSE). And it also has two teams. Design team A and design team B which we regard as design resources. When A is assigned to SSE and B to SHD. We break down the project as shown in Fig 1.It is alike to manage other resources in a project in this way. So when we define a collaborative design project’s task model, we should first claim the project’s targets. These targets include functional goals, performance goals, and quality goals and so on. Then we could confirm how to execute this project. Next we can go on to break down it. The project can be separated into two or more subtasks since there are at 1east two partners in a collaborative project. Either we could separate the project into stepwise tasks, which have time sequence relationships in case of some more complex projects and then break down the stepwise tasks according to their phase-to-phase goals.There is also another trouble in executing a task breakdown. When a task is broken into s evera1 subtasks; it is not merely “a simple sum motion” of other tasks. In most cases their subtasks could have more complex relations.To solve this problem we use constraints. There are time sequence constraint (TSC) and logic constraint (LC). The time sequence constraint defines the time relationships among subtasks. The TSC has four different types, FF, FS, SF and SS. F means finish and S presents start. If we say T abb is FS and lag four days, it means Tb should start no later than four days after Ta is finished.The logic constraint is much more complicated. It defines logic relationship among multiple tasks.Here is given an example:“Task TA is separated into three subtasks, Ta, T b and Tc. But there are two more rules.Tb and Tc can not be executed until Ta is finished.Tb and Tc can not be executed both，that means if Tb was executed, Tc should not be executed, and vice versa. This depends on the result of Ta.”So we say Tb and Tc have a logic constraint. After finishing breaking down the tasks, we canget a task tree as Fig, 2 illustrates.4 TMS Realization4.1 TMS StructureAccording to our discussion about task tree model and task breakdown basis, we can develop a Task Management System (TMS) based on Co Design Space using Java language, JSP technology and Microsoft SQL 2000. The task management system’s structure is shown in Fig. 3.TMS has four main modules namely Task Breakdown, Role Management, Statistics and Query and Data Integration. The Task Breakdown module helps users to work out task tree. Role Management module performs authentication and authorization of access control. Statistics and Query module is an extra tool for users to find more information about their task. The last Data Integration Module provides in/out interface for TMS with its peripheral environment.4.2 Key Points in System Realization4.2.1 Integration with Co Design SpaceCo Design Space is an integrated information management system which stores, shares and processes design data and provides a series of tools to support users. These tools can share all information in the database because they have a universal Data Mode1. Which is defined in an XML (extensible Markup Language) file, and has a hierarchical structure. Based on this XML structure the TMS h data mode1 definition is organized as following.<?xml version= 1.0 encoding= UTF-8’?><!--comment：Common Resource Definitions Above．The Followingare Task Design--><!ELEMENT ProductProcessResource (Prcses?, History?，AsBuiltProduct*，ItemsObj?, Changes?, ManufacturerParts?，SupplierParts?，AttachmentsObj? ，Contacts?，PartLibrary?，AdditionalAttributes*)><!ELEMENT Prcses (Prcs+) ><!ELEMENT Prcs (Prcses，PrcsNotes?，PrcsArc*，Contacts?，AdditionalAttributes*，Attachments?)><!ELEM ENT PrcsArc EMPTY><!ELEMENT PrcsNotes(PrcsNote*)><!ELEMENT PrcsNote EMPTY>Notes: Element “Pros” is a task node object, and “Process” is a task set object which contains subtask objects and is belongs to a higher class task object. One task object can have no more than one “Presses”objects. According to this definition, “Prcs” objects are organized in a tree-formation process. The other objects are resources, such as task link object (“Presage”), task notes (“Pros Notes”), and task documents (“Attachments”) .These resources are shar ed in Co Design database.。
英文文献原文及翻译
外文文献翻译学生姓名：周千琪论文题目：基于的图书管理系统指导教师：武新丽技术职称：讲师原文：Visual Basic language and arithmeticThe summary of Microsoft Visual StudioMicrosoft Visual Basic (abbreviate VB) as tool the most of application program one of under Windows operating platform. No matter beginner or professional developer, VB has all offered a whole set of tools to them, Development application program that it can be relaxed and convenient. So VB as most computer first-selected the ABC of programming language of beginner." Visual" mean method to adopt visual user of development figure interface (GUI), need and write a large number of code go and describe interface appearance and position of element seldom, Tow and show controlling part that need corresponding position to get screen can help figure design interface, user of figure,; " Basic" means BASIC language, because VB is developed on the basis of already existing BAISC language.VB is a kind of programming language in common use of Microsoft, It, including VBA of the numerous Windows application software use VB language in Microsoft Excel, Microsoft Accessed., For users to carry on the secondary development; Make web page use more VBScript script language sub collection of VB too at present.Utilize data of VB visit characteristic user can establish the data base to most data base forms including Microsoft SQL Server and other enterprises data base With the application program of front, and adjustable service end part. Utilize ActiveX(TM) technology, VB can use word processor, electronic data list he Windows function that application program offers extremely, Excel of Microsoft,, Word of Microsoft,, Even can use by VB specialty edition or enterprise application program and target that edition establish directly.Integrated development environmentsIntegrated environment of VB call IDE, made up of a lot of parts , include title board, menu fence, tool fence, controlling part case, And window body window, engineering management devicewindow, attribute window, code window and window body overall arrangement window bodyoverall arrangement, etc. of designing etc.. Have covered all functions, such as design which develops the application program, editting, compiling and debugging, etc .In VB, the application program calls the project too. When start VB and open a new project for the first time, can see and pursue integrated development environment interface that show.VB come and organize development of application program through project, use project come and manage and form files of application program. One project uses the environment to make up by several window bodies, standard module generally. The system manages project through the project menu, for instance add the window body, quote . System allow turn on and manage a lot of projects besides.Visual Basic language brief introductionsBasic use and do the elementary high-level language that used often most. Its full name is Beginner' s All-purpose Symbolic Instruction Code, abbreviate as BASIC. As its name suggests, Basic one specially for language that beginner design, because it easy to learn easy to know, So the body is popular. Early Basic language to belong to and solve translating type, so can carry out line by line , So it can see the result carried out at once , this is a very convenient design for beginner. But it have concept of structure either, one that is in procedure maintain and management have as much as other language problems. But back-end Basic correct shortcoming of the above (such as Quick Basic), make it may used for and develop the large-scaler procedure too.The language is the basic composition, which forms VB procedure. VB has stipulated the form ofsentences and function.Grammar:The sentence defines incantations [Sentence body]Sentence define agree with and used in fixed function of sentence, sentence body appoint concrete content or want concrete operation that carry out of sentence. All set of sentence VB language, carry on with VB sentence organic association finish a certain specific function the procedure. Interface + procedure can solve a certain application problem.VB application program code window write in" code editing machine" generally. " editing machine of code" is like the word processing software of a piece of height specialization, there aremany easies function of writing VB code, Pursue to show [Example Ex-Hello ]In" code editing machine" code that window written.“Editing machine of code” windowDevelop the application program with Visual BasicUse VB programming, design appearance of application program first generally, write every target procedure code or other treatment procedure of incident respectively, Work of programming should be light more.The procedure of establishing the application program is as follows:Establish application program interfaceThe interface is the mutual bridge of user and procedure, Generally formed of window body and vision frame of the button, menu, text frameset. with standard WINDOWS interface of application program that VB establish. Require according to function of procedure and user and need of information interchange of procedure, Come to confirm that need those targets , plan the overall arrangement of the interface.2. Design by each attributes of target in interfaceDemand and set up each attribute of target such as appearance, name,, size of targeted. according to interface of planning.Most attribute person who fetch can set up through the attribute window when design already, Too can set up revising when operating in procedure through programming in procedure code. Have the targets respond programming by procedure code3. Respond procedure code of programming targetInterface determine appearance of procedure only, design window add codes through" code editing machine" soon after the interface, Realize some make the tasks, such as responding, information processing,etc. after accepting external message, Add code , realize some response, information processing that make after accepting external information task.4. Keep projectOne VB procedure one project, at the time of designing a application program, system will set up one be expanded and called. Project file of vbp, project file include all relevant information of file that project set up this, Keep project keep associated documents of project this at the same time. For example the window body produced when design interfaces is kept and being expanded andbeing called. Frm sum. In the window body of foxfire. At the time of opening a project( file), this project relevant files load at the same time.5. Operate and debugged by procedureOperate the procedure thoroughpin operate" selecting in the menu, when the mistake appears, VB system can offer information prompt can looked for and get rid of the mistake thoroughpin debug" within operate" menus too.6. Can produce by executive programFor make procedure can break away from VB environment, order to become next life through" file"" producing project 1.exe" of menu but executive program (eyeful), Can carry out this file directly after this. In produce, + executive program, and then through install guide bale all associated documents, Can run independently after installation under the environment of windows 9 x/2000 as a software product.Visual Basic algorithmIn computer system's any software, is by the every large or small each kind of software constituent constitution, defers to the specific algorithm to realize respectively, the algorithm quality direct decision realizes the software performance fit and unfit quality. Designs the algorithm with any method, what resources designs the algorithm to need, requires how many running time, how many storage space, how to determine an algorithm the quality, when realizes a software, is must give to solve. In computer system's operating system, the language compiling system, the database management system as well as in various computer application system's software, must use each one concrete algorithm to realize. Therefore, the algorithm design and the analysis are the computer science and a technical core question.The algorithm is the problem-solving step, we may define the algorithm Cheng Jie a determination class question the random one special method. In the computer science, the algorithm needs to use the computer algorithmic language to describe, the algorithm represents with the computer solves a kind of question precisely, the effective method. The algorithm construction of data = procedure, solves one to assign may calculate or the solvable question, the different person may compile the different procedure, solves the identical problem, here has two problems: First, with computational method close related algorithm question; Second, programming technical question. Between the algorithm and the procedure has the close relationship. The algorithm is a group has the poor rule, they had stipulated solves some specifictype question a series of operations, is to the problem solving plan accurate and the complete description. Formulates an algorithm, generally must pass through stages and so on design, confirmation, analysis, code, test, debugging, time. To algorithm study including five aspect contents:①Design algorithm. The algorithm design work is impossible completely the automation, should study the understanding already by the practice to prove that was the useful some basic algorithm design method, these basic design method was not only suitable for the computer science, moreover was suitable for domains and so on electrical engineering, operations research;② Expresses the algorithm. The description algorithm's method has many kinds of forms, for example the natural language and the algorithmic language, have the suitable environment and the characteristic respectively;③Confirms the algorithm. The algorithm confirmed the goal is causes the people to believe firmly that this algorithm can work unmistakably correctly, namely this algorithm has the circularity. The correct algorithm describes with the computer algorithmic language, constitutes the computer program, the computer program moves on the computer, obtains the algorithm operation result;④ Parsing algorithm. The algorithmic analysis is requires how many computing time and the storage space to an algorithm makes the quota the analysis. The parsing algorithm may forecast that what environment this algorithm does suit in moves effectively, to solves the identical question different algorithm validity to make the comparison;⑤Confirmation algorithm. With machine language description algorithm whether can calculate effectively, reasonable, must carry on the test to the procedure, the test order work and makes the space and time distribution map by the debugging to be composed.But the algorithm has certain characteristic, it includes:① Determinism. Algorithm each kind of operation must have the determination significance, this kind of operation should carry out what kind of movement should not to have the ambiguity, the goal is clear;②Effectiveness. Requests the operation which in the algorithm waits for realizing is basic, each kind of operation can at least completes in the principle by the human with the paper and the pen in the limited time;③ Input. An algorithm has 0 or the many inputs, before the algorithm operation starts gives the algorithm to need the data the starting value, these inputs are from the specific object set;④Output. Does for the algorithm operation result, an algorithm has or many outputs, the output has some kind of specific relational quantity with the input;⑤ Has poor. An algorithm always after carrying out had the poor step operation has terminated, namely this algorithm was may reach.Satisfies a first four characteristic group of rule not to be able to be called the algorithm, can only be called the computational process, the operating system is a computational process example, the operating system uses for to manage the computer resources, controls the manufacture industry movement, when has not made industry the movement, the computational process does not stop, but is at the waiting status.The algorithm complexity is the algorithm efficiency measure, when appraises the algorithm performance, the complexity is an important basis. The algorithm complex degree with moves computer resources how many which this algorithm needs related, needs the resources are more, indicated that this algorithm the complexity is higher; Needs the resources are less, indicated that this algorithm the complexity is lower.The spatial resources, which computer’s resources, operate most importantly, needs the time which and the stored routine and the data need, the algorithm complexity has division time complexity and the spatial complexity.The algorithm carries out the operation on the computer, needs the data which certain storage space depositing description algorithm the procedure and the algorithm need, the computer completes the operation task to require certain time. The procedure which writes according to the different algorithm places when on the computer operates, needs the time and the space are different, the algorithm complexity is needs the time and the spatial one kind of measure to the algorithm operation. The different computer its operating speed difference is very big, is weighing an algorithm the complexity to note this point.Regarding question, which assigns willfully, a profitable target which designs, the complex low algorithm is as far as possible when designs algorithm considered. Moreover, when the question, which assigns already when has many kinds of algorithms, an important criterion which choice complexity low, is when selects algorithm should follow. Therefore, the algorithm complex analysis or selects to the algorithm design has the important guiding sense and the use value.外文文献中文翻译学生姓名：周千琪论文题目：基于的图书管理系统指导教师：武新丽技术职称：讲师译文：Visual Basic 语言与算法Visual Basic的概述Microsoft Visual Basic(简称VB)是在Windows操作平台下设计应用程序的最速度、最简捷的工具之一。
英文文献小短文(原文加汉语翻译)
A fern that hyperaccumulates arsenic(这是题目，百度一下就能找到原文好，原文还有表格，我没有翻译)A hardy, versatile, fast-growing plant helps to remove arsenic from contaminated soilsContamination of soils with arsenic,which is both toxic and carcinogenic, is widespread1. We have discovered that the fern Pteris vittata (brake fern) is extremely efficient in extracting arsenic from soils and translocating it into its above-ground biomass. This plant —which, to our knowledge, is the first known arsenic hyperaccumulator as well as the first fern found to function as a hyperaccumulator— has many attributes that recommend it for use in the remediation of arsenic-contaminated soils.We found brake fern growing on a site in Central Florida contaminated with chromated copper arsenate (Fig. 1a). We analysed the fronds of plants growing at the site for total arsenic by graphite furnace atomic absorption spectroscopy. Of 14 plant species studied, only brake fern contained large amounts of arsenic (As;3,280–4,980 p.p.m.). We collected additional samples of the plant and soil from the contaminated site (18.8–1,603 p.p.m. As) and from an uncontaminated site (0.47–7.56 p.p.m. As). Brake fern extracted arsenic efficiently from these soils into its fronds: plants growing in the contaminated site contained 1,442–7,526p.p.m. Arsenic and those from the uncontaminated site contained 11.8–64.0 p.p.m. These values are much higher than those typical for plants growing in normal soil, which contain less than 3.6 p.p.m. of arsenic3.As well as being tolerant of soils containing as much as 1,500 p.p.m. arsenic, brake fern can take up large amounts of arsenic into its fronds in a short time (Table 1). Arsenic concentration in fern fronds growing in soil spiked with 1,500 p.p.m. Arsenic increased from 29.4 to 15,861 p.p.m. in two weeks. Furthermore, in the same period, ferns growing in soil containing just 6 p.p.m. arsenic accumulated 755 p.p.m. Of arsenic in their fronds, a 126-fold enrichment. Arsenic concentrations in brake fern roots were less than 303 p.p.m., whereas those in the fronds reached 7,234 p.p.m.Addition of 100 p.p.m. Arsenic significantly stimulated fern growth, resulting in a 40% increase in biomass compared with the control (data not shown).After 20 weeks of growth, the plant was extracted using a solution of 1:1 methanol:water to speciate arsenic with high-performance liquid chromatography–inductively coupled plasma mass spectrometry. Almostall arsenic was present as relatively toxic inorganic forms, with little detectable organoarsenic species4. The concentration of As(III) was greater in the fronds (47–80%) than in the roots (8.3%), indicating that As(V) was converted to As(III) during translocation from roots to fronds.As well as removing arsenic from soils containing different concentrations of arsenic (Table 1), brake fern also removed arsenic from soils containing different arsenic species (Fig. 1c). Again, up to 93% of the arsenic was concentrated in the fronds. Although both FeAsO4 and AlAsO4 are relatively insoluble in soils1, brake fern hyperaccumulated arsenic derived from these compounds into its fronds (136–315 p.p.m.)at levels 3–6 times greater than soil arsenic.Brake fern is mesophytic and is widely cultivated and naturalized in many areas with a mild climate. In the United States, it grows in the southeast and in southern California5. The fern is versatile and hardy, and prefers sunny (unusual for a fern) and alkaline environments (where arsenic is more available). It has considerable biomass, and is fast growing, easy to propagate,and perennial.We believe this is the first report of significant arsenic hyperaccumulationby an unmanipulated plant. Brake fern has great potential to remediate arsenic-contaminated soils cheaply and could also aid studies of arsenic uptake, translocation, speciation, distribution and detoxification in plants. *Soil and Water Science Department, University ofFlorida, Gainesville, Florida 32611-0290, USAe-mail: lqma@†Cooperative Extension Service, University ofGeorgia, Terrell County, PO Box 271, Dawson,Georgia 31742, USA‡Department of Chemistry & SoutheastEnvironmental Research Center, FloridaInternational University, Miami, Florida 33199,1. Nriagu, J. O. (ed.) Arsenic in the Environment Part 1: Cyclingand Characterization (Wiley, New York, 1994).2. Brooks, R. R. (ed.) Plants that Hyperaccumulate Heavy Metals (Cambridge Univ. Press, 1998).3. Kabata-Pendias, A. & Pendias, H. in Trace Elements in Soils and Plants 203–209 (CRC, Boca Raton, 1991).4. Koch, I., Wang, L., Ollson, C. A., Cullen, W. R. & Reimer, K. J. Envir. Sci. Technol. 34, 22–26 (2000).5. Jones, D. L. Encyclopaedia of Ferns (Lothian, Melbourne, 1987).积累砷的蕨类植物耐寒，多功能，生长快速的植物，有助于从污染土壤去除砷有毒和致癌的土壤砷污染是非常广泛的。
外文文献翻译原文+译文
外文文献翻译原文Analysis of Con tin uous Prestressed Concrete BeamsChris BurgoyneMarch 26, 20051、IntroductionThis conference is devoted to the development of structural analysis rather than the strength of materials, but the effective use of prestressed concrete relies on an appropriate combination of structural analysis techniques with knowledge of the material behaviour. Design of prestressed concrete structures is usually left to specialists; the unwary will either make mistakes or spend inordinate time trying to extract a solution from the various equations.There are a number of fundamental differences between the behaviour of prestressed concrete and that of other materials. Structures are not unstressed when unloaded; the design space of feasible solutions is totally bounded；in hyperstatic structures, various states of self-stress can be induced by altering the cable profile, and all of these factors get influenced by creep and thermal effects. How were these problems recognised and how have they been tackled?Ever since the development of reinforced concrete by Hennebique at the end of the 19th century (Cusack 1984), it was recognised that steel and concrete could be more effectively combined if the steel was pretensioned, putting the concrete into compression. Cracking could be reduced, if not prevented altogether, which would increase stiffness and improve durability. Early attempts all failed because the initial prestress soon vanished, leaving the structure to be- have as though it was reinforced; good descriptions of these attempts are given by Leonhardt (1964) and Abeles (1964).It was Freyssineti’s observations of the sagging of the shallow arches on three bridges that he had just completed in 1927 over the River Allier near Vichy which led directly to prestressed concrete (Freyssinet 1956). Only the bridge at Boutiron survived WWII (Fig 1). Hitherto, it had been assumed that concrete had a Young’s modulus which remained fixed, but he recognised that the de- ferred strains due to creep explained why the prestress had been lost in the early trials. Freyssinet (Fig. 2) also correctly reasoned that high tensile steel had to be used, so that some prestress would remain after the creep had occurred, and alsothat high quality concrete should be used, since this minimised the total amount of creep. The history of Freyssineti’s early prestressed concrete work is written elsewhereFigure1:Boutiron Bridge,Vic h yFigure 2: Eugen FreyssinetAt about the same time work was underway on creep at the BRE laboratory in England ((Glanville 1930) and (1933)). It is debatable which man should be given credit for the discovery of creep but Freyssinet clearly gets the credit for successfully using the knowledge to prestress concrete.There are still problems associated with understanding how prestressed concrete works, partly because there is more than one way of thinking about it. These different philosophies are to some extent contradictory, and certainly confusing to the young engineer. It is also reflected, to a certain extent, in the various codes of practice.Permissible stress design philosophy sees prestressed concrete as a way of avoiding cracking by eliminating tensile stresses; the objective is for sufficient compression to remain after creep losses. Untensionedreinforcement, which attracts prestress due to creep, is anathema. This philosophy derives directly from Freyssinet’s logic and is primarily a working stress concept.Ultimate strength philosophy sees prestressing as a way of utilising high tensile steel as reinforcement. High strength steels have high elastic strain capacity, which could not be utilised when used as reinforcement; if the steel is pretensioned, much of that strain capacity is taken out before bonding the steel to the concrete. Structures designed this way are normally designed to be in compression everywhere under permanent loads, but allowed to crack under high live load. The idea derives directly from the work of Dischinger (1936) and his work on the bridge at Aue in 1939 (Schonberg and Fichter 1939), as well as that of Finsterwalder (1939). It is primarily an ultimate load concept. The idea of partial prestressing derives from these ideas.The Load-Balancing philosophy, introduced by T.Y. Lin, uses prestressing to counter the effect of the permanent loads (Lin 1963). The sag of the cables causes an upward force on the beam, which counteracts the load on the beam. Clearly, only one load can be balanced, but if this is taken as the total dead weight, then under that load the beam will perceive only the net axial prestress and will have no tendency to creep up or down.These three philosophies all have their champions, and heated debates take place between them as to which is the most fundamental.2、Section designFrom the outset it was recognised that prestressed concrete has to be checked at both the working load and the ultimate load. For steel structures, and those made from reinforced concrete, there is a fairly direct relationship between the load capacity under an allowable stress design, and that at the ultimate load under an ultimate strength design. Older codes were based on permissible stresses at the working load; new codes use moment capacities at the ultimate load. Different load factors are used in the two codes, but a structure which passes one code is likely to be acceptable under the other.For prestressed concrete, those ideas do not hold, since the structure is highly stressed, even when unloaded. A small increase of load can cause some stress limits to be breached, while a large increase in load might be needed to cross other limits. The designer has considerable freedom to vary both the working load and ultimate load capacities independently; both need to be checked.A designer normally has to check the tensile and compressive stresses, in both the top and bottom fibre of the section, for every load case. The critical sections are normally, but not always, the mid-span and the sections over piers but other sections may become critical ，when the cable profile has to be determined.The stresses at any position are made up of three components, one of which normally has a different sign from the other two; consistency of sign convention is essential.If P is the prestressing force and e its eccentricity, A and Z are the area of the cross-section and its elastic section modulus, while M is the applied moment, then where ft and fc are the permissible stresses in tension and compression.c e t f ZM Z P A P f ≤-+≤Thus, for any combination of P and M , the designer already has four in- equalities to deal with.The prestressing force differs over time, due to creep losses, and a designer isusually faced with at least three combinations of prestressing force and moment;• the applied moment at the time the prestress is first applied, before creep losses occur,• the maximum applied moment after creep losses, and• the minimum applied moment after creep losses.Figure 4: Gustave MagnelOther combinations may be needed in more complex cases. There are at least twelve inequalities that have to be satisfied at any cross-section, but since an I-section can be defined by six variables, and two are needed to define the prestress, the problem is over-specified and it is not immediately obvious which conditions are superfluous. In the hands of inexperienced engineers, the design process can be very long-winded. However, it is possible to separate out the design of the cross-section from the design of the prestress. By considering pairs of stress limits on the same fibre, but for different load cases, the effects of the prestress can be eliminated, leaving expressions of the form:rangestress e Perm issibl Range Mom entZ These inequalities, which can be evaluated exhaustively with little difficulty, allow the minimum size of the cross-section to be determined.Once a suitable cross-section has been found, the prestress can be designed using a construction due to Magnel (Fig.4). The stress limits can all be rearranged into the form:()M fZ PA Z e ++-≤1 By plotting these on a diagram of eccentricity versus the reciprocal of the prestressing force, a series of bound lines will be formed. Provided the inequalities (2) are satisfied, these bound lines will always leave a zone showing all feasible combinations of P and e. The most economical design, using the minimum prestress, usually lies on the right hand side of the diagram, where the design is limited by the permissible tensile stresses.Plotting the eccentricity on the vertical axis allows direct comparison with the crosssection, as shown in Fig. 5. Inequalities (3) make no reference to the physical dimensions of the structure, but these practical cover limits can be shown as wellA good designer knows how changes to the design and the loadings alter the Magnel diagram. Changing both the maximum andminimum bending moments, but keeping the range the same, raises and lowers the feasible region. If the moments become more sagging the feasible region gets lower in the beam.In general, as spans increase, the dead load moments increase in proportion to the live load. A stage will be reached where the economic point (A on Fig.5) moves outside the physical limits of the beam; Guyon (1951a) denoted the limiting condition as the critical span. Shorter spans will be governed by tensile stresses in the two extreme fibres, while longer spans will be governed by the limiting eccentricity and tensile stresses in the bottom fibre. However, it does not take a large increase in moment ，at which point compressive stresses will govern in the bottom fibre under maximum moment.Only when much longer spans are required, and the feasible region moves as far down as possible, does the structure become governed by compressive stresses in both fibres.3、Continuous beamsThe design of statically determinate beams is relatively straightforward; the engineer can work on the basis of the design of individual cross-sections, as outlined above. A number of complications arise when the structure is indeterminate which means that the designer has to consider, not only a critical section,but also the behaviour of the beam as a whole. These are due to the interaction of a number of factors, such as Creep, Temperature effects and Construction Sequence effects. It is the development of these ideas whichforms the core of this paper. The problems of continuity were addressed at a conference in London (Andrew and Witt 1951). The basic principles, and nomenclature, were already in use, but to modern eyes concentration on hand analysis techniques was unusual, and one of the principle concerns seems to have been the difficulty of estimating losses of prestressing force.3.1 Secondary MomentsA prestressing cable in a beam causes the structure to deflect. Unlike the statically determinate beam, where this motion is unrestrained, the movement causes a redistribution of the support reactions which in turn induces additional moments. These are often termed Secondary Moments, but they are not always small, or Parasitic Moments, but they are not always bad.Freyssinet’s bridge across the Marne at Luzancy, started in 1941 but not completed until 1946, is often thought of as a simply supported beam, but it was actually built as a two-hinged arch (Harris 1986), with support reactions adjusted by means of flat jacks and wedges which were later grouted-in (Fig.6). The same principles were applied in the later and larger beams built over the same river.Magnel built the first indeterminate beam bridge at Sclayn, in Belgium (Fig.7) in 1946. The cables are virtually straight, but he adjusted the deck profile so that the cables were close to the soffit near mid-span. Even with straight cables the sagging secondary momentsare large; about 50% of the hogging moment at the central support caused by dead and live load.The secondary moments cannot be found until the profile is known but the cablecannot be designed until the secondary moments are known. Guyon (1951b) introduced the concept of the concordant profile, which is a profile that causes no secondary moments; es and ep thus coincide. Any line of thrust is itself a concordant profile.The designer is then faced with a slightly simpler problem; a cable profile has to be chosen which not only satisfies the eccentricity limits (3) but is also concordant. That in itself is not a trivial operation, but is helped by the fact that the bending moment diagram that results from any load applied to a beam will itself be a concordant profile for a cable of constant force. Such loads are termed notional loads to distinguish them from the real loads on the structure. Superposition can be used to progressively build up a set of notional loads whose bending moment diagram gives the desired concordant profile.3.2 Temperature effectsTemperature variations apply to all structures but the effect on prestressed concrete beams can be more pronounced than in other structures. The temperature profile through the depth of a beam (Emerson 1973) can be split into three components for the purposes of calculation (Hambly 1991). The first causes a longitudinal expansion, which is normally released by the articulation of the structure; the second causes curvature which leads to deflection in all beams and reactant moments in continuous beams, while the third causes a set of self-equilibrating set of stresses across the cross-section.The reactant moments can be calculated and allowed-for, but it is the self- equilibrating stresses that cause the main problems for prestressed concrete beams. These beams normally have high thermal mass which means that daily temperature variations do not penetrate to the core of the structure. The result is a very non-uniform temperature distribution across the depth which in turn leads to significant self-equilibrating stresses. If the core of the structure is warm, while the surface is cool, such as at night, then quite large tensile stresses can be developed on the top and bottom surfaces. However, they only penetrate a very short distance into the concrete and the potential crack width is very small. It can be very expensive to overcome the tensile stress by changing the section or the prestress。
机械类外文文献翻译(中英文翻译)
机械类外文文献翻译(中英文翻译)英文原文Mechanical Design and Manufacturing ProcessesMechanical design is the application of science and technology to devise new or improved products for the purpose of satisfying human needs. It is a vast field of engineering technology which not only concerns itself with the original conception of the product in terms of its size, shape and construction details, but also considers the various factors involved in the manufacture, marketing and use of the product.People who perform the various functions of mechanical design are typically called designers, or design engineers. Mechanical design is basically a creative activity. However, in addition to being innovative, a design engineer must also have a solid background in the areas of mechanical drawing, kinematics, dynamics, materials engineering, strength of materials and manufacturing processes.As stated previously, the purpose of mechanical design is to produce a product which will serve a need for man. Inventions, discoveries and scientific knowledge by themselves do not necessarily benefit people; only if they are incorporated into a designed product will a benefit be derived. It should be recognized, therefore, that a human need must be identified before a particular product is designed.Mechanical design should be considered to be an opportunity to use innovative talents to envision a design of a product, to analyze the systemand then make sound judgments on how the product is to be manufactured. It is important to understand the fundamentals of engineering rather than memorize mere facts and equations. There are no facts or equations which alone can be used to provide all the correct decisions required to produce a good design.On the other hand, any calculations made must be done with the utmost care and precision. For example, if a decimal point is misplaced, an otherwise acceptable design may not function.Good designs require trying new ideas and being willing to take a certain amount of risk, knowing that if the new idea does not work the existing method can be reinstated. Thus a designer must have patience, since there is no assurance of success for the time and effort expended. Creating a completely new design generally requires that many old and well-established methods be thrust aside. This is not easy since many people cling to familiar ideas, techniques and attitudes. A design engineer should constantly search for ways to improve an existing product and must decide what old, proven concepts should be used and what new, untried ideas should be incorporated.New designs generally have "bugs" or unforeseen problems which must be worked out before the superior characteristics of the new designs can be enjoyed. Thus there is a chance for a superior product, but only at higher risk. It should be emphasized that, if a design does not warrant radical new methods, such methods should not be applied merely for the sake of change.During the beginning stages of design, creativity should be allowedto flourish without a great number of constraints. Even though many impractical ideas may arise, it is usually easy to eliminate them in the early stages of design before firm details are required by manufacturing. In this way, innovative ideas are not inhibited. Quite often, more than one design is developed, up to the point where they can be compared against each other. It is entirely possible that the design which is ultimately accepted will use ideas existing in one of the rejected designs that did not show as much overall promise.Psychologists frequently talk about trying to fit people to the machines they operate. It is essentially the responsibility of the design engineer to strive to fit machines to people. This is not an easy task, since there is really no average person for which certain operating dimensions and procedures are optimum.Another important point which should be recognized is that a design engineer must be able to communicate ideas to other people if they are to be incorporated. Communicating the design to others is the final, vital step in the design process. Undoubtedly many great designs, inventions, and creative works have been lost to mankind simply because the originators were unable or unwilling to explain their accomplishments to others. Presentation is a selling job. The engineer, when presenting a new solution to administrative, management, or supervisory persons, is attempting to sell or to prove to them that this solution is a better one. Unless this can be done successfully, the time and effort spent on obtaining the solution have been largely wasted.Basically, there are only three means of communication available tous. These are the written, the oral, and the graphical forms. Therefore the successful engineer will be technically competent and versatile in all three forms of communication. A technically competent person who lacks ability in any one of these forms is severely handicapped. If ability in all three forms is lacking, no one will ever know how competent that person is!The competent engineer should not be afraid of the possibility of not succeeding in a presentation. In fact, occasional failure should be expected because failure or criticism seems to accompany every really creative idea. There is a great deal to be learned from a failure, and the greatest gains are obtained by those willing to risk defeat. In the final analysis, the real failure would lie in deciding not to make the presentation at all. To communicate effectively, the following questions must be answered:(1) Does the design really serve a human need?(2) Will it be competitive with existing products of rival companies?(3) Is it economical to produce?(4) Can it be readily maintained?(5) Will it sell and make a profit?Only time will provide the true answers to the preceding questions, but the product should be designed, manufactured and marketed only with initial affirmative answers. The design engineer also must communicate the finalized design to manufacturing through the use of detail and assembly drawings.Quite often, a problem will occur during the manufacturing cycle [3].It may be that a change is required in the dimensioning or tolerancing of a part so that it can be more readily produced. This fails in the category of engineering changes which must be approved by the design engineer so that the product function will not be adversely affected. In other cases, a deficiency in the design may appear during assembly or testing just prior to shipping. These realities simply bear out the fact that design is a living process. There is always a better way to do it and the designer should constantly strive towards finding that better way.Designing starts with a need, real or imagined. Existing apparatus may need improvements in durability, efficiently, weight, speed, or cost. New apparatus may be needed to perform a function previously done by men, such as computation, assembly, or servicing. With the objective wholly or partly defined, the next step in design is the conception of mechanisms and their arrangements that will perform the needed functions.For this, freehand sketching is of great value, not only as a record of one's thoughts and as an aid in discussion with others, but particularly for communication with one's own mind, as a stimulant for creative ideas.When the general shape and a few dimensions of the several components become apparent, analysis can begin in earnest. The analysis will have as its objective satisfactory or superior performance, plus safety and durability with minimum weight, and a competitive east. Optimum proportions and dimensions will be sought for each critically loaded section, together with a balance between the strength of the several components. Materials and their treatment will be chosen. These important objectives can be attained only by analysis based upon the principles ofmechanics, such as those of statics for reaction forces and for the optimumutilization of friction; of dynamics for inertia, acceleration, and energy; of elasticity and strength of materials for stress。
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 。
儿童教育外文翻译文献
儿童教育外文翻译文献(文档含中英文对照即英文原文和中文翻译)原文：The Role of Parents and Community in the Educationof the Japanese ChildHeidi KnipprathAbstractIn Japan, there has been an increased concern about family and community participation in the child’s educat ion. Traditionally, the role of parents and community in Japan has been one of support and less one of active involvement in school learning. Since the government commenced education reforms in the last quarter of the 20th century, a more active role for parents and the community in education has been encouraged. These reforms have been inspired by the need to tackle various problems that had arisen, such as the perceived harmful elements of society’spreoccupation with academic achievement and the problematic behavior of young people. In this paper, the following issues are examined: (1) education policy and reform measures with regard to parent and community involvement in the child’s education; (2) the state of parent and community involvement at the eve of the 20th century.Key Words: active involvement, community, education reform, Japan, parents, partnership, schooling, supportIntroduction: The Discourse on the Achievement GapWhen western observers are tempted to explain why Japanese students attain high achievement scores in international comparative assessment studies, they are likely to address the role of parents and in particular of the mother in the education of the child. Education mom is a phrase often brought forth in the discourse on Japanese education to depict the Japanese mother as being a pushy, and demanding home-bound tutor, intensely involved in the child’s education due to severe academic competition. Although this image of the Japanese mother is a stereotype spread by the popular mass media in Japan and abroad, and the extent by which Japanese mothers are absorbed in their children is exaggerated (Benjamin, 1997, p. 16; Cummings, 1989, p. 297; Stevenson & Stigler, 1992, p. 82), Stevenson and Stigler (1992) argue that Japanese parents do play an indispensable role in the academic performance of their children. During their longitudinal and cross-national research project, they and their collaborators observed that Japanese first and fifth graders persistently achieved higher on math tests than American children. Besides reciting teacher’s teaching style, cultural beliefs, and organization of schooling, Stevenson and Stigler (1992) mention parent’s role in supporting the learning conditions of the child to explain differences in achievement between elementary school students of the United States and students of Japan. In Japan, children receive more help at home with schoolwork (Chen & Stevenson, 1989; Stevenson & Stigler, 1992), and tend to perform less household chores than children in the USA (Stevenson et al., 1990; Stevenson & Stigler, 1992). More Japanese parents than American parents provide space and a personal desk and purchase workbooks for their children to supplement their regular text-books at school (Stevenson et al., 1990; Stevenson & Stigler, 1992). Additionally, Stevenson and Stigler (1992) observed that American mothers are much more readily satisfied with their child’s performance than Asian parents are, have less realistic assessments of their child’s academic perform ance, intelligence, and other personality characteristics, and subsequently have lower standards. Based on their observation of Japanese, Chinese and American parents, children and teachers, Stevenson and Stigler (1992) conclude that American families can increase the academic achievement of their children by strengthening the link between school and home, creating a physical and psychological environment that is conducive to study, and by making realistic assessments and raising standards. Also Benjamin (1997), who performed ‘day-to-day ethnography’ to find out how differences in practice between American and Japanese schools affect differences in outcomes, discusses the relationship between home and school and how the Japanese mother is involved in the academic performance standards reached by Japanese children. She argues that Japanese parents are willing to pay noticeable amounts of money for tutoring in commercial establishments to improve the child’s performance on entrance examinations, to assist in ho mework assignments, to facilitate and support their children’s participation in school requirements and activities, and to check notebooks of teachers on the child’s progress and other school-related messages from the teacher. These booklets are read and written daily by teachers and parents. Teachers regularly provide advice and reminders to parents, and write about homework assignments of the child, special activities and the child’s behavior (Benjamin, 1997, p. 119, p. 1993–1995). Newsletters, parents’ v isits to school, school reports, home visits by the teacher and observation days sustain communication in later years at school. According toBenjamin (1997), schools also inform parents about how to coach their children on proper behavior at home. Shimahara (1986), Hess and Azuma (1991), Lynn (1988) and White (1987) also try to explain national differences in educational achievement. They argue that Japanese mothers succeed in internalizing into their children academic expectations and adaptive dispositions that facilitate an effective teaching strategy, and in socializing the child into a successful person devoted to hard work.Support, Support and SupportEpstein (1995) constructed a framework of six types of involvement of parents and the community in the school: (1) parenting: schools help all families establish home environments to support children as students; (2) communicating: effective forms of school-to-home and home-to-school communications about school programs and children’s progress; (3) volu nteering: schools recruit and organize parents help and support; (4) learning at home: schools provide information and ideas to families about how to help students at home with homework and other curriculum-related activities, decisions and planning; (5) decision making: schools include parents in school decisions, develop parent leaders and representatives; and (6) collaborating with the community: schools integrate resources and services from the community to strengthen school programs, family practices, and student learning and development. All types of involvement mentioned in studies of Japanese education and in the discourse on the roots of the achievement gap belong to one of Epstein’s first four types of involvement: the creation of a conducive learn ing environment (type 4), the expression of high expectations (type 4), assistance in homework (type 4), teachers’ notebooks (type 2), mother’s willingness to facilitate school activities (type3) teachers’ advice about the child’s behavior (type 1), observ ation days by which parents observe their child in the classroom (type 2), and home visits by the teachers (type 1). Thus, when one carefully reads Stevenson and Stigler’s, Benjamin’s and other’s writings about Japanese education and Japanese students’ high achievement level, one notices that parents’ role in the child’s school learning is in particular one of support, expected and solicited by the school. The fifth type (decision making) as well as the sixth type (community involvement) is hardly ever mentioned in the discourse on the achievement gap.In 1997, the OECD’s Center for Educational Research and Innovation conducted a cross-national study to report the actual state of parents as partners in schooling in nine countries, including Japan. In its report, OECD concludes that the involvement of Japanese parents in their schools is strictly limited, and that the basis on which it takes place tends to be controlled by the teacher (OECD, 1997, p. 167). According to OECD (1997), many countries are currently adopting policies to involve families closely in the education of their children because (1) governments are decentralizing their administrations; (2) parents want to be increasingly involved; and (3) because parental involvement is said to be associated with higher achievement in school (p. 9). However, parents in Japan, where students already score highly on international achievement tests, are hardly involved in governance at the national and local level, and communication between school and family tends to be one-way (Benjamin, 1997; Fujita, 1989; OECD, 1997). Also parent–teacher associations (PTA, fubo to kyoshi no kai ) are primarily presumed to be supportive of school learning and not to participate in school governance (cf. OECD, 2001, p. 121). On the directionsof the occupying forces after the second world war, PTA were established in Japanese schools and were considered with the elective education boards to provide parents and the community an opportunity to participate actively in school learning (Hiroki, 1996, p. 88; Nakata, 1996, p. 139). The establishment of PTA and elective education boards are only two examples of numerous reform measures the occupying forces took to decentralize the formal education system and to expand educational opportunities. But after they left the country, the Japanese government was quick to undo liberal education reform measures and reduced the community and parental role in education. The stipulation that PTA should not interfere with personnel and other administrative tasks of schools, and the replacement of elective education boards by appointed ones, let local education boards believe that parents should not get involved with school education at all (Hiroki, 1996, p. 88). Teachers were regarded to be the experts and the parents to be the laymen in education (Hiroki, 1996, p. 89).In sum, studies of Japanese education point into one direction: parental involvement means being supportive, and community involvement is hardly an issue at all. But what is the actual state of parent and community involvement in Japanese schools? Are these descriptions supported by quantitative data?Statistics on Parental and Community InvolvementTo date, statistics of parental and community involvement are rare. How-ever, the school questionnaire of the TIMSS-R study did include some interesting questions that give us a clue about the degree of involvement relatively compared to the degree of involvement in other industrialized countries. The TIMSS-R study measured science and math achievement of eighth graders in 38 countries. Additionally, a survey was held among principals, teachers and students. Principals answered questions relating to school management, school characteristics, and involvement. For convenience, the results of Japan are only compared with the results of those countries with a GNP of 20650 US dollars or higher according to World Bank’s indicators in 1999.Unfortunately, only a very few items on community involvement were measured. According to the data, Japanese principals spend on average almost eight hours per month on representing the school in the community (Table I). Australian and Belgian principals spend slightly more hours and Dutch and Singaporean principals spend slightly less on representing the school and sustaining communication with the community. But when it comes to participation from the community, Japanese schools report a nearly absence of involvement (Table II). Religious groups and the business community have hardly any influence on the curriculum of the school. In contrast, half of the principals report that parents do have an impact in Japan. On one hand, this seems a surprising result when one is reminded of the centralized control of the Ministry of Education. Moreover, this control and the resulting uniform curriculum are often cited as a potential explanation of the high achievement levels in Japan. On the other hand, this extent of parental impact on the curriculum might be an indicator of the pressure parents put on schools to prepare their children appropriately for the entrance exams of senior high schools.In Table III, data on the extent of other types of parental involvement in Japan and other countries are given. In Japan, parental involvement is most common in case of schools volunteering for school projects and programs, and schools expecting parents to make sure that thechild completes his or her homework. The former is together with patrolling the grounds of the school to monitor student behavior most likely materialized through the PTA. The kinds and degree of activities of PTA vary according to the school, but the activities of the most active and well-organized PTA’s of 395 elementary schools investigated by Sumida (2001)range from facilitating sport and recreation for children, teaching greetings, encouraging safe traffic, patrolling the neighborhood, publishing the PTA newspaper to cleaning the school grounds (pp. 289–350). Surprisingly, less Japanese principals expect from the parents to check one’s child’s completion of homework than principals of other countries. In the discourse on the achievement gap, western observers report that parents and families in Japan provide more assistance with their children’s homework than parents and families outside Japan. This apparent contradiction might be the result of the fact that these data are measured at the lower secondary level while investigations of the roots of Japanese students’ high achievement levels focus on childhood education and learning at primary schools. In fact, junior high school students are given less homework in Japan than their peers in other countries and less homework than elementary school students in Japan. Instead, Japanese junior high school students spend more time at cram schools. Finally, Japanese principals also report very low degrees of expectations toward parents with regard to serving as a teacher aid in the classroom, raising funds for the school, assisting teachers on trips, and serving on committees which select school personnel and review school finances. The latter two items measure participation in school governance.In other words, the data support by and large the descriptions of parental of community involvement in Japanese schooling. Parents are requested to be supportive, but not to mount the territory of the teacher nor to be actively involved in governance. Moreover, whilst Japanese principals spend a few hours per month on communication toward the community, involvement from the community with regard to the curriculum is nearly absent, reflecting the nearly absence of accounts of community involvement in studies on Japanese education. However, the reader needs to be reminded that these data are measured at the lower secondary educational level when participation by parents in schooling decreases (Epstein, 1995; OECD, 1997; Osakafu Kyoiku Iinkai, unpublished report). Additionally, the question remains what stakeholders think of the current state of involvement in schooling. Some interesting local data provided by the Osaka Prefecture Education Board shed a light on their opinion.ReferencesBenjamin, G. R. (1997). Japanese lessons. New York: New York University Press.Cave, P. (2003). Educational reform in Japan in the 1990s: ‘Individuality’ and other uncertainties. Comparative Education Review, 37(2), 173–191.Chen, C., & Stevenson, H. W. (1989). Homework: A cross-cultural examination. Child Development, 60(3), 551–561.Chuo Kyoiku Shingikai (1996). 21 seiki o tenbo shita wagakuni no kyoiku no arikata ni tsu-ite [First Report on the Model for Japanese Education in the Perspective of theCummings, W. K. (1989). The American perception of Japanese parative Education, 25(3), 293–302.Epstein, J. L. (1995). School/family/community partnerships. Phi Delta Kappan , 701–712.Fujita, M. (1989). It’s all mother’s fault: childcare and the socialization of working mothers in Japan. The Journal of Japanese Studies , 15(1), 67–91.Harnish, D. L. (1994). Supplemental education in Japan: juku schooling and its implication. Journal of Curriculum Studies , 26(3), 323–334.Hess, R. D., & Azuma, H. (1991). Cultural support for schooling, contrasts between Japanand the United States. Educational Researcher , 20(9), 2–8, 12.Hiroki, K. (1996). Kyoiku ni okeru kodomo, oya, kyoshi, kocho no kenri, gimukankei[Rights and duties of principals, teachers, parents and children in education. InT. Horio & T. Urano (Eds.), Soshiki toshite no gakko [School as an organization](pp. 79–100). Tokyo: Kashiwa Shobo. Ikeda, H. (2000). Chiiki no kyoiku kaikaku [Local education reform]. Osaka: Kaiho Shup-pansha.Kudomi, Y., Hosogane, T., & Inui, A. (1999). The participation of students, parents and the community in promoting school autonomy: case studies in Japan. International Studies in Sociology of Education, 9(3), 275–291.Lynn, R. (1988).Educational achievement in Japan. London: MacMillan Press.Martin, M. O., Mullis, I. V. S., Gonzalez, E. J., Gregory, K. D., Smith, T. A., Chrostowski,S. J., Garden, R. A., & O’Connor, K. M. (2000). TIMSS 1999 Intern ational science report, findings from IEA’s Repeat of the Third International Mathematics and ScienceStudy at the Eight Grade.Chestnut Hill: The International Study Center.Mullis, I. V. S., Martin, M. O., Gonzalez, E. J., Gregory, K. D., Garden, R. A., O’Connor, K. M.,Chrostowski, S. J., & Smith, T. A.. (2000). TIMSS 1999 International mathemat-ics report, findings from IEA’s Repeat of the Third International Mathematics and Science Study at the Eight Grade.Chestnut Hill: The International Study Center. Ministry of Education, Science, Sports and Culture (2000).Japanese government policies in education, science, sports and culture. 1999, educational reform in progress. Tokyo: PrintingBureau, Ministry of Finance.Monbusho Ed. (1999).Heisei 11 nendo, wagakuni no bunkyoshisaku : Susumu kaikaku [Japanese government policies in education, science, sports and culture 1999: Educational reform in progress]. Tokyo: Monbusho.Educational Research for Policy and Practice (2004) 3: 95–107 © Springer 2005DOI 10.1007/s10671-004-5557-6Heidi KnipprathDepartment of MethodologySchool of Business, Public Administration and TechnologyUniversity of Twente P.O. Box 2177500 AE Enschede, The Netherlands译文：家长和社区在日本儿童教育中的作用摘要在日本，人们越来越关心家庭和社区参与到儿童教育中。
- 1、下载文档前请自行甄别文档内容的完整性，平台不提供额外的编辑、内容补充、找答案等附加服务。
- 2、"仅部分预览"的文档,不可在线预览部分如存在完整性等问题,可反馈申请退款(可完整预览的文档不适用该条件!)。
- 3、如文档侵犯您的权益，请联系客服反馈,我们会尽快为您处理(人工客服工作时间：9:00-18:30)。
一种马来西亚车牌定位识别系统Velappa GANAPATHY 1School of Engineering, Monash University Malaysia 2 Jalan Kolej, Bandar Sunway, PetalingJaya, Selangor MalaysiaandWen Lik Dennis LUI 2School of Engineering, Monash University Malaysia2 Jalan Kolej, Bandar Sunway, Petaling Jaya, Selangor Malaysia摘要：在交通系统中，智能科技产品广受欢迎。
这些只能系统给不仅有助于交通检测，在机动车安全，执法机关和商业应用中也大有益处。
本文提出了一种适于马来西亚车辆的车牌定位和识别系统。
此系统基于数字图像处理开发，且可以方便的应用于商业泊车系统并为停车服务提供文本记录，保障车库安全，并且可以预防车辆盗窃事件。
本文中提出的车牌定位算法基于一个形态学和改进的霍夫变换方法处理得到，车牌识别通过使用前向传播和反向传播人造神经网络。
一个复杂室外环境中捕捉到的589张图片的成功识别率为95%。
关键词：车牌，霍夫变换，反向传播，定位，字符分割识别和自动改正。
1.引言：通常来说，要给自动车牌定位和识别系统（ALPR）由三个模块组成；车牌定位，字符分割和光学字符识别模块（图.1）。
图.1.传统ALPR系统的流程图数字图像的车牌定位一般是通过使用边缘提取，直方图分析，形态算子或霍夫变换实现。
边缘提取通常比较简单和快捷。
但是，对方对噪声敏感。
如果车牌是由直线段组的则使用霍夫变换可以得到很好的结果。
但是，需要车牌的轮廓明显。
且需要很大的内存空间和相当长的运算时间。
另一方面，基础的直方图处理不能处理有大量噪声和倾斜的车牌。
最后：使用形态学方法处理不易受到噪声的影响，但是执行起来很慢。
单独使用这些技术不足以满足现代系统的需求。
现在，一个智能车牌定位和识别系统需要稳定的运行在复杂的背景环境和光强度变化。
因此:已经提出了很多解决方案来应对这些问题。
比如：Kim，S. et al[1]提出了一种基于边缘提取的在弱光环境下的车牌定位方法。
它由两步组成。
第一步包含对输入图像的梯度信息的相应区域进行搜索，第二步确定车牌的在候选区域的位置，并通过引用一个车牌模板调整边缘。
此外，Sarfraz，M.et al[2]利用垂直边缘检测和沙特阿拉伯车牌。
可以看出车牌图像拥有更多的水平线条，这种方法通过仅仅检测垂直线条而减少了计算时间。
在[3]和[4]中，讨论更多的边缘提取方法。
在使用形态学方法的案例中，Dubey，P.[5]修改常见的形态学方法使用试探法得到一个在复杂图像处理的更简洁的结果。
相应的，Wu，C. et al [6]结合形态学算子和一个澳门车辆搜索算法映射。
这个搜索映射算法通过水平和垂直映射检测车牌中的字符区域。
澳门车牌风格和马来西亚的车牌风格非常相似，因此，其可以作为一个可靠的参考方案。
车牌定位之后是自负分割。
常见的自负分割方法是基于直方图和阈值分析。
近期被提出的方法，比如Fukumi，M. et al [7]使用人工神经网络确定最有的阈值，Kahraman，F. et al [8]使用Gabor变换和向量量化方法，Song，H. et al [9]。
系统的最后一个阶段是字符识别。
Wu，C. et al [6] 、Naito，T. et al [10] 采用更易实施的模板匹配法。
但是，为了处理从多种车牌中读取的各种字符，需要分割字符以进行一些处理步骤，如：归一化和倾斜矫正。
这些额外的步骤被证明有效的减少了所需的计算时间。
例如：Sarfraz，M. et al [2]通过在模板匹配之前进行归一化改进了模板匹配法。
更先进技术包括使用神经网络[10,11]和自组织地图[12]。
2.系统概述和其核心概念在此项工作中主要使用的软件是Matlab R2006a（v.7.2）。
使用此软件的核心组件是图像处理工具包（IPT）和神经网络工具包。
使用一个英特尔奔腾3.0GHz双核处理器和1Gb 内存的计算机执行此软件，使用一个索尼DSC-P10数码相机捕捉到589张数码图像。
数码图像拥有1百万像素的分辨率不使用相机的任何附加功能。
刻意这样做是为了使实验结果能够验证所提算法的鲁棒性。
图2.索尼DSC-P10 数码相机自动车牌识别系统的历史是相当复杂的，且有很多已经被成功的应用的在商业用途。
然而，在马来西亚设计一个车牌识别系统不仅需要系统处理车牌光照变化，污染，扭曲等客观环境。
也需要系统处理一些非标准的马来西亚风格车牌。
为了使系统在这些环境下稳定的运行，提出并开发了一个基于形态处理和改进的霍夫变换相结合的方式。
通常，霍夫变换被用来定位车牌的垂直和水平边缘。
这在Tran，D. D. et al [13]的工作中有清楚的说明。
实验小组结合霍夫变换和用于探测封闭边缘对象轮廓的算法。
此技术降低了内存空间和运算需求。
然而，这不适用于马来西亚的车牌定位。
这主要是由于大多数马来西亚车牌没有一个清晰的边界。
且白色的字符在黑色背景上不像其他国家车牌的黄色或白色背景那样易于区分。
这样，为此系统开发的车牌定位过程的核心概念仅仅基于字符特征而不是车牌的轮廓。
这是因为自符是车牌上面最容易分辨的对象。
接下来的部分讨论定位，自负分割和识别模块。
接着，文章会在结束之前分析和讨论实验结果。
3.车牌定位如前所述，车牌定位过程是一个形态学过程和改进的霍夫变化方法的结合。
为了执行形态处理，通常将原始的RGB图像转换为一个灰度图转换为二进制图像会更方便。
Otsu的通用阈值转换方法被用在此系统中将灰度图转换为二进制图。
这项技术推荐最小化目标和背景像素的内部类型差异用来得到一个最优的阈值。
这个通用阈值转换方法会将生成如图3所指的二进制图像。
图3.Otsu通用阈值转换结果如图3所示，可以清楚的看到，车牌的字符已经被正确的从其背景中分离了出来。
接着，在二进制图像上面执行多种形态处理和霍夫变换。
在接下来的分段中讨论自动倾斜矫正和候选区域评估，从而完成车牌定位模块。
形态处理形态处理的目的是去除图像中所有的无关对象并且确保车牌上的字符被完整保留。
然而，为了保证算法足够完善以满足各种大小的字符，将在此图像中进行若干形态处理。
这是为了保证能够为每个过程指定一个宽松的上限和有限的下线。
基于已测得的对象性质，将会校对已指定的上限和下限用来决定其是否保留或从图像中移除。
主要有三个形态处理过程被用于此图像。
每个二进制图像的宽度，高度，和小孔的数量将被核对。
超过指定上限和下限的值将从图像中移除。
这个步骤在从图像中填充和清除边界对象和去除微小对象处理之后。
图4清楚的阐明了这些步骤。
图4.形态处理流程图改进的霍夫变换如上述所说，霍夫变换通常用于检测车牌的边缘。
在此系统中，检测的重点是车牌的字符。
在使用霍夫变换的大多数案例中，输入图像一般是边缘图像。
案后，定位车牌的水平和垂直边框。
然而，在本系统中，不需要边缘图像。
相反地，霍夫变换被直接应用于经过形态处理后字符特征得到保留的图片。
通常，一旦得到霍夫变换后的图像，峰值就被确 Binary Image Fill Image Clear Boundary ObjectsRemove Small ObjectsWidth, Height and Holes定了，这些峰值对应图像中直线的位置，然后和一个空的二进制图像对比（全为0）。
在空图像中这些线段所对应的像素值被置为1。
目标中的线段彼此交叉。
最终，这会使对象的边界位置容易被找到。
因此，通过检索图像中所有的交叉线段边界框的特征，得到这些线段围成的候选区域，接着被显示在原始图中。
图5.说明了改进的霍夫变换处理为了确保使用这种方法能够得到一个满意的结果，指定这些参数的合理值是非常重要的，如霍夫变换中用来确定峰值的阈值，检测峰值个数和线段的最大和最小长度。
图5.改进的霍夫变换的流程图如果检测到了过多的线条，则此过程将很慢。
反之亦然，如果检测到的线条数目与理论值相差很大。
则可能不会差生一个覆盖整个车牌的候选区域。
同样的，理想的配置是从最小的线条中提取到整个车牌。
需要注意的是，通常会得到不止一个候选区域。
在对候选区域进行评估之前，需要执行自动倾斜校正。
自动倾斜校正自动校正的主要目标是改进候选评估过程和提高字符识别模块的识别成功率。
自动校正也是基于霍夫变换的。
改进霍夫变换得到的最终候选区域作为此步处理的输入。
图6. 显示了一些包含车牌的候选区域样本。
从这些样本可以看出，之后的提取被成功的执行了，但是经过第一次形态处理得到的图像总任然存在一些不需要的目标。
为了去除这些目标，进行第二次形态处理，包括边框过滤，紧接着进行候选区的小目标去除和填充。
值得注意的是，第二次形态处理不包括清楚便捷对象以避免字符被移除。
Plotting Lines on Empty ImageDisplay on Grayscale ImageLocating Peaks on Hough Transform After Morpho. Processes图6.候选区样本在使用霍夫变换实现自动校正的案例中，第二次形态处理的结果图像使用Sobel 算子获得轮廓。
相似的，峰值对应的直线位置在霍夫图中标示出，检测到的线条标示在轮廓图中。
目标线段是最上方线段（所有字符边缘的上方）或最下方线段（所有字符边缘的下方）。
这两条线段将帮助计算车牌的相对于水平轴的倾斜角。
在此系统中，将最底部线段作为目标线段。
同样的，对于所有的候选区域来说，最低线将被确定。
为了在霍夫图中的所以的线段中找到这条线，需要建立几个标准。
最低线的最明显的特征是，它的有坐标平均值-从起点到终点最大（Matlab 中的图像坐标系统）。
但是，可能出现这种情况，由于候选区中异物的影响目标线段可能会丢失这种特征。
外物的存在主要原因是第二次形态处理失败。
这样，为了控制这种情况，每条线的长度和斜度将被纳入考虑范围。
成功定位最低线之后，车牌对于水平轴的角度可以使用简单的三角定理得到。
图7.阐明了自动校正过程图7.自动校正处理流程图候选区判定如前文所述，改进的霍夫变换法通常会定位不止一个的候选区（图8中有说明）。
为了确定包含车牌的正确的候选区需要对候选区进行判定。
此判定过程有几个测试组成，这些测试检测候选区中存在车牌的可能性。
只有通过所有测试的候选区才会被判定为车牌。
这 Plot and Locate Bottom Most LineAuto Skew Correction on Original Candidate Region Locating Peaks on Hough Plot After 2 ndMorph. Process Locating Peaks on Hough Plot Auto Skew Correction on Original Candidate RegionPlot and Locate Bottom Most LineAfter 2 nd Morph. Process些测试包括：候选区的宽高比和候选区中封闭图形的个数。