外文文献-翻译

合集下载

外文文献及翻译

外文文献及翻译

外文文献原稿和译文原稿DATABASEA database may be defined as a collection interrelated data store together with as little redundancy as possible to serve one or more applications in an optimal fashion .the data are stored so that they are independent of programs which use the data .A common and controlled approach is used in adding new data and in modifying and retrieving existing data within the data base .One system is said to contain a collection of database if they are entirely separate in structure .A database may be designed for batch processing , real-time processing ,or in-line processing .A data base system involves application program, DBMS, and database.THE INTRODUCTION TO DATABASE MANAGEMENT SYSTEMSThe term database is often to describe a collection of related files that is organized into an integrated structure that provides different people varied access to the same data. In many cases this resource is located in different files in different departments throughout the organization, often known only to the individuals who work with their specific portion of the total information. In these cases, the potential value of the information goes unrealized because a person in other departments who may need it does not know it or it cannot be accessed efficiently. In an attempt to organize their information resources and provide for timely and efficient access, many companies have implemented databases.A database is a collection of related data. By data, we mean known facts that can be recorded and that have implicit meaning. For example, the names, telephone numbers, and addresses of all the people you know. You may have recorded this data in an indexed address book, or you may have stored it on a diskette using a personalcomputer and software such as DBASE Ⅲor Lotus 1-2-3. This is a collection of related data with an implicit meaning and hence is a database.The above definition of database is quite general. For example, we may consider the collection of words that made up this page of text to be usually more restricted. A database has the following implicit properties:● A database is a logically coherent collection of data with some inherent meaning. A random assortment of data cannot be referred to as a database.● A database is designed, built, and populated with data for a specific purpose. It has an intended group of user and some preconceived applications in which these users are interested.● A database represents some aspect of the real world, sometimes called the miniworld. Changes to the miniworld are reflected in the database.In other words, a database has some source from which data are derived, some degree of interaction with events in the real world, and an audience that is actively interested in the contents of the database.A database management system (DBMS) is composed of three major parts: (1) a storage subsystem that stores and retrieves data in files; (2)a modeling and manipulation subsystem that provides the means with which to organize the data and to add, delete, maintain, and update the data; and (3) an interface between the DBMS and its users. Several major trends are emerging that enhance the value and usefulness of database management systems.●Managers who require more up-to-date information to make effective decisions.●Customers who demand increasingly sophisticated information services and more current information about the status of their orders, invoices, and accounts.●Users who find that they can develop custom applications with database systems in a fraction of the time it takes to use traditional programming languages.●Organizations that discover information has a strategic value; they utilize their database systems to gain an edge over their competitors.A DBMS can organize, process, and present selected data elements from the database. This capability enables decision makers to search, probe, and query database contents in order to extract answers to nonrecurring and unplanned questions that aren’t available in regular reports. These questions might initially be vague and/or p oorly defined, but people can “browse” through the database until they have the needed information. In short, the DBMS will “mange” the stored data items and assemble the needed items from the common database in response to the queries of those who aren’t programmers. In a file-oriented system, user needing special information may communicate their needs to a programmer, who, when time permits, will write one or more programs to extract the data and prepare the information. The availability of a DBMS, however, offers users a much faster alternative communications path.DATABASE QUERYIf the DBMS provides a way to interactively enter and update the database ,as well as interrogate it ,this capability allows for managing personal database. However, it does not automatically leave an audit trail of actions and does not provide the kinds of controls necessary in a multi-user organization .There controls are only available when a set of application programs is customized for each data entry and updating function.Software for personal computers that perform some of the DBMS functions has been very popular .Individuals for personal information storage and processing intended personal computers for us .Small enterprises, professionals like doctors, architects, engineers, lawyers and so on have also used these machines extensively. By the nature of intended usage ,database system on there machines are except from several of the requirements of full-fledged database systems. Since data sharing is not intended, concurrent operations even less so ,the software can be less complex .Security and integrity maintenance are de-emphasized or absent .as data volumes will be small, performance efficiency is also less important .In fact, the only aspect of a database system that is important is data independence. Data independence ,as stated earlier ,means that application programs and user queries need not recognize physical organization of data on secondary storage. The importance of this aspect , particularly for the personal computer user ,is that this greatly simplifies database usage . The user can store ,access and manipulate data at ahigh level (close to the application)and be totally shielded from the low level (close to the machine )details of data organization.DBMS STRUCTURING TECHNIQUESSpatial data management has been an active area of research in the database field for two decades ,with much of the research being focused on developing data structures for storing and indexing spatial data .however, no commercial database system provides facilities for directly de fining and storing spatial data ,and formulating queries based on research conditions on spatial data.There are two components to data management: history data management and version management .Both have been the subjects of research for over a decade. The troublesome aspect of temporal data management is that the boundary between applications and database systems has not been clearly drawn. Specifically, it is not clear how much of the typical semantics and facilities of temporal data management can and should be directly incorporated in a database system, and how much should be left to applications and users. In this section, we will provide a list of short-term research issues that should be examined to shed light on this fundamental question.The focus of research into history data management has been on defining the semantics of time and time interval, and issues related to understanding the semantics of queries and updates against history data stored in an attribute of a record. Typically, in the context of relational databases ,a temporal attribute is defined to hold a sequence of history data for the attribute. A history data consists of a data item and a time interval for which the data item is valid. A query may then be issued to retrieve history data for a specified time interval for the temporal attribute. The mechanism for supporting temporal attributes is to that for supporting set-valued attributes in a database system, such as UniSQL.In the absence of a support for temporal attributes, application developers who need to model and history data have simply simulated temporal attributes by creating attribute for the time interval ,along with the “temporal” attribute. This of course may result in duplication of records in a table, and more complicated search predicates in queries. The one necessary topic of research in history data management is to quantitatively establish the performance (and even productivity) differences betweenusing a database system that directly supports attributes and using a conventional database system that does not support either the set-valued attributes or temporal attributes.Data security, integrity, and independenceData security prevents unauthorized users from viewing or updating the database. Using passwords, users are allowed access to the entire database of the database, called subschemas. For example, an employee database can contain all the data about an individual employee, but one group of users may be authorized to view only payroll data, while others are allowed access to only work history and medical data.Data integrity refers to the accuracy, correctness, or validity of the data in the database. In a database system, data integrity means safeguarding the data against invalid alteration or destruction. In large on-line database system, data integrity becomes a more severe problem and two additional complications arise. The first has to do with many users accessing the database concurrently. For example, if thousands of travel agents book the same seat on the same flight, the first agent’s booking will be lost. In such cases the technique of locking the record or field provides the means for preventing one user from accessing a record while another user is updating the same record.The second complication relates to hardware, software or human error during the course of processing and involves database transaction which is a group of database modifications treated as a single unit. For example, an agent booking an airline reservation involves several database updates (i.e., adding the passenger’s name and address and updating the seats-available field), which comprise a single transaction. The database transaction is not considered to be completed until all updates have been completed; otherwise, none of the updates will be allowed to take place.An important point about database systems is that the database should exist independently of any of the specific applications. Traditional data processing applications are data dependent.When a DMBS is used, the detailed knowledge of the physical organization of the data does not have to be built into every application program. The application program asks the DBMS for data by field name, for example, a coded representationof “give me customer name and balance due” would be sent to the DBMS. Without a DBMS the programmer must reserve space for the full structure of the record in the program. Any change in data structure requires changes in all the applications programs.Data Base Management System (DBMS)The system software package that handles the difficult tasks associated with creating ,accessing and maintaining data base records is called a data base management system (DBMS). A DBMS will usually be handing multiple data calls concurrently.It must organize its system buffers so that different data operations can be in process together .It provides a data definition language to specify the conceptual schema and most likely ,some of the details regarding the implementation of the conceptual schema by the physical schema.The data definition language is a high-level language, enabling one to describe the conceptual schema in terms of a “data model “.At the present time ,there are four underling structures for database management systems. They are :List structures.Relational structures.Hierarchical (tree) structures.Network structures.Management Information System(MIS)An MIS can be defined as a network of computer-based data processing procedures developed in an organization and integrated as necessary with manual and other procedures for the purpose of providing timely and effective information to support decision making and other necessary management functions.One of the most difficult tasks of the MIS designer is to develop the information flow needed to support decision making .Generally speaking ,much of the information needed by managers who occupy different levels and who have different levels and have different responsibilities is obtained from a collection of exiting information system (or subsystems)Structure Query Language (SQL)SQL is a data base processing language endorsed by the American NationalStandards Institute. It is rapidly becoming the standard query language for accessing data on relational databases .With its simple ,powerful syntax ,SQL represents a great progress in database access for all levels of management and computing professionals.SQL falls into two forms : interactive SQL and embedded SQL. Embedded SQL usage is near to traditional programming in third generation languages .It is the interactive use of SQL that makes it most applicable for the rapid answering of ad hoc queries .With an interactive SQL query you just type in a few lines of SQL and you get the database response immediately on the screen.译文数据库数据库可以被定义为一个相互联系的数据库存储的集合。

外文文献翻译译稿和原文

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。

外文文献翻译(图片版)

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。

毕业设计论文外文文献翻译

毕业设计论文外文文献翻译

毕业设计(论文)外文文献翻译院系:财务与会计学院年级专业:201*级财务管理姓名:学号:132148***附件: 财务风险管理【Abstract】Although financial risk has increased significantly in recent years risk and risk management are not contemporary issues。

The result of increasingly global markets is that risk may originate with events thousands of miles away that have nothing to do with the domestic market。

Information is available instantaneously which means that change and subsequent market reactions occur very quickly。

The economic climate and markets can be affected very quickly by changes in exchange rates interest rates and commodity prices。

Counterparties can rapidly become problematic。

As a result it is important to ensure financial risks are identified and managed appropriately. Preparation is a key component of risk management。

【Key Words】Financial risk,Risk management,YieldsI. Financial risks arising1.1What Is Risk1.1.1The concept of riskRisk provides the basis for opportunity. The terms risk and exposure have subtle differences in their meaning. Risk refers to the probability of loss while exposure is the possibility of loss although they are often used interchangeably。

外文文献及翻译

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

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。

外文文献及翻译

外文文献及翻译

Yunnan Ethnic pattern in Packaging DesignAbstract: Art is a folk Mother of the arts,is the source of the new art, From which to draw a strong tradition of high—grade Nutrition。

The persons belonging to national folk arts Ethnic patterns,are folk arts Intraoperative a gem, its development Research,and with the means of modern art,art wind Grid,professional skills combine to form a unique Style and features a modern design There are important applications,this paper focuses on Minority Folk pattern in modern packaging design Meter applications are discussed.Keywords: Yunnan Ethnic. Pattern。

Packaging Design.IntroductionYunnan is a multi-ethnic province, Here multiply survive the Han, Yi, Bai More than twenty families, Zhuang, Miao, Dai, etc。

Nation. Long history of various ethnic groups in Yunnan Province, the source is far Long, creating a rich and colorful Folk art。

外文参考文献(带中文翻译)

外文参考文献(带中文翻译)

外文资料原文涂敏之会计学 8051208076Title:Future of SME finance(c)Background – the environment for SME finance has changedFuture economic recovery will depend on the possibility of Crafts, Trades and SMEs to exploit their potential for growth and employment creation.SMEs make a major contribution to growth and employment in the EU and are at the heart of the Lisbon Strategy, whose main objective is to turn Europe into the most competitive and dynamic knowledge-based economy in the world. However, the ability of SMEs to grow depends highly on their potential to invest in restructuring, innovation and qualification. All of these investments need capital and therefore access to finance.Against this background the consistently repeated complaint of SMEs about their problems regarding access to finance is a highly relevant constraint that endangers the economic recovery of Europe.Changes in the finance sector influence the behavior of credit institutes towards Crafts, Trades and SMEs. Recent and ongoing developments in the banking sector add to the concerns of SMEs and will further endanger their access to finance. The main changes in the banking sector which influence SME finance are:•Globalization and internationalization have increased the competition and the profit orientation in the sector;•worsening of the economic situations in some institutes (burst of the ITC bubble, insolvencies) strengthen the focus on profitability further;•Mergers and restructuring created larger structures and many local branches, which had direct and personalized contacts with small enterprises, were closed;•up-coming implementation of new capital adequacy rules (Basel II) will also change SME business of the credit sector and will increase its administrative costs;•Stricter interpretation of State-Aide Rules by the European Commission eliminates the support of banks by public guarantees; many of the effected banks are very active in SME finance.All these changes result in a higher sensitivity for risks and profits in the financesector.The changes in the finance sector affect the accessibility of SMEs to finance.Higher risk awareness in the credit sector, a stronger focus on profitability and the ongoing restructuring in the finance sector change the framework for SME finance and influence the accessibility of SMEs to finance. The most important changes are: •In order to make the higher risk awareness operational, the credit sector introduces new rating systems and instruments for credit scoring;•Risk assessment of SMEs by banks will force the enterprises to present more and better quality information on their businesses;•Banks will try to pass through their additional costs for implementing and running the new capital regulations (Basel II) to their business clients;•due to the increase of competition on interest rates, the bank sector demands more and higher fees for its services (administration of accounts, payments systems, etc.), which are not only additional costs for SMEs but also limit their liquidity;•Small enterprises will lose their personal relationship with decision-makers in local branches –the credit application process will become more formal and anonymous and will probably lose longer;•the credit sector will lose more and more i ts “public function” to provide access to finance for a wide range of economic actors, which it has in a number of countries, in order to support and facilitate economic growth; the profitability of lending becomes the main focus of private credit institutions.All of these developments will make access to finance for SMEs even more difficult and / or will increase the cost of external finance. Business start-ups and SMEs, which want to enter new markets, may especially suffer from shortages regarding finance. A European Code of Conduct between Banks and SMEs would have allowed at least more transparency in the relations between Banks and SMEs and UEAPME regrets that the bank sector was not able to agree on such a commitment.Towards an encompassing policy approach to improve the access of Crafts, Trades and SMEs to financeAll analyses show that credits and loans will stay the main source of finance for the SME sector in Europe. Access to finance was always a main concern for SMEs, but the recent developments in the finance sector worsen the situation even more.Shortage of finance is already a relevant factor, which hinders economic recovery in Europe. Many SMEs are not able to finance their needs for investment.Therefore, UEAPME expects the new European Commission and the new European Parliament to strengthen their efforts to improve the framework conditions for SME finance. Europe’s Crafts, Trades and SMEs ask for an encompassing policy approach, which includes not only the conditions for SMEs’ access to l ending, but will also strengthen their capacity for internal finance and their access to external risk capital.From UEAPME’s point of view such an encompassing approach should be based on three guiding principles:•Risk-sharing between private investors, financial institutes, SMEs and public sector;•Increase of transparency of SMEs towards their external investors and lenders;•improving the regulatory environment for SME finance.Based on these principles and against the background of the changing environment for SME finance, UEAPME proposes policy measures in the following areas:1. New Capital Requirement Directive: SME friendly implementation of Basel IIDue to intensive lobbying activities, UEAPME, together with other Business Associations in Europe, has achieved some improvements in favour of SMEs regarding the new Basel Agreement on regulatory capital (Basel II). The final agreement from the Basel Committee contains a much more realistic approach toward the real risk situation of SME lending for the finance market and will allow the necessary room for adaptations, which respect the different regional traditions and institutional structures.However, the new regulatory system will influence the relations between Banks and SMEs and it will depend very much on the way it will be implemented into European law, whether Basel II becomes burdensome for SMEs and if it will reduce access to finance for them.The new Capital Accord form the Basel Committee gives the financial market authorities and herewith the European Institutions, a lot of flexibility. In about 70 areas they have room to adapt the Accord to their specific needs when implementing itinto EU law. Some of them will have important effects on the costs and the accessibility of finance for SMEs.UEAPME expects therefore from the new European Commission and the new European Parliament:•The implementation of the new Capital Requirement Directive will be costly for the Finance Sector (up to 30 Billion Euro till 2006) and its clients will have to pay for it. Therefore, the implementation – especially for smaller banks, which are often very active in SME finance –has to be carried out with as little administrative burdensome as possible (reporting obligations, statistics, etc.).•The European Regulators must recognize traditional instruments for collaterals (guarantees, etc.) as far as possible.•The European Commission and later the Member States should take over the recommendations from the European Parliament with regard to granularity, access to retail portfolio, maturity, partial use, adaptation of thresholds, etc., which will ease the burden on SME finance.2. SMEs need transparent rating proceduresDue to higher risk awareness of the finance sector and the needs of Basel II, many SMEs will be confronted for the first time with internal rating procedures or credit scoring systems by their banks. The bank will require more and better quality information from their clients and will assess them in a new way. Both up-coming developments are already causing increasing uncertainty amongst SMEs.In order to reduce this uncertainty and to allow SMEs to understand the principles of the new risk assessment, UEAPME demands transparent rating procedures –rating procedures may not become a “Black Box” for SMEs: •The bank should communicate the relevant criteria affecting the rating of SMEs.•The bank should inform SMEs about its assessment in order to allow SMEs to improve.The negotiations on a European Code of Conduct between Banks and SMEs , which would have included a self-commitment for transparent rating procedures by Banks, failed. Therefore, UEAPME expects from the new European Commission and the new European Parliament support for:•binding rules in the framework of the new Capital Adequacy Directive,which ensure the transparency of rating procedures and credit scoring systems for SMEs;•Elaboration of national Codes of Conduct in order to improve the relations between Banks and SMEs and to support the adaptation of SMEs to the new financial environment.3. SMEs need an extension of credit guarantee systems with a special focus on Micro-LendingBusiness start-ups, the transfer of businesses and innovative fast growth SMEs also depended in the past very often on public support to get access to finance. Increasing risk awareness by banks and the stricter interpretation of State Aid Rules will further increase the need for public support.Already now, there are credit guarantee schemes in many countries on the limit of their capacity and too many investment projects cannot be realized by SMEs.Experiences show that Public money, spent for supporting credit guarantees systems, is a very efficient instrument and has a much higher multiplying effect than other instruments. One Euro form the European Investment Funds can stimulate 30 Euro investments in SMEs (for venture capital funds the relation is only 1:2).Therefore, UEAPME expects the new European Commission and the new European Parliament to support:•The extension of funds for national credit guarantees schemes in the framework of the new Multi-Annual Programmed for Enterprises;•The development of new instruments for securitizations of SME portfolios;•The recognition of existing and well functioning credit guarantees schemes as collateral;•More flexibility within the European Instruments, because of national differences in the situation of SME finance;•The development of credit guarantees schemes in the new Member States;•The development of an SBIC-like scheme in the Member States to close the equity gap (0.2 – 2.5 Mio Euro, according to the expert meeting on PACE on April 27 in Luxemburg).•the development of a financial support scheme to encourage the internalizations of SMEs (currently there is no scheme available at EU level: termination of JOP, fading out of JEV).4. SMEs need company and income taxation systems, whichstrengthen their capacity for self-financingMany EU Member States have company and income taxation systems with negative incentives to build-up capital within the company by re-investing their profits. This is especially true for companies, which have to pay income taxes. Already in the past tax-regimes was one of the reasons for the higher dependence of Europe’s SMEs on bank lending. In future, the result of rating w ill also depend on the amount of capital in the company; the high dependence on lending will influence the access to lending. This is a vicious cycle, which has to be broken.Even though company and income taxation falls under the competence of Member States, UEAPME asks the new European Commission and the new European Parliament to publicly support tax-reforms, which will strengthen the capacity of Crafts, Trades and SME for self-financing. Thereby, a special focus on non-corporate companies is needed.5. Risk Capital – equity financingExternal equity financing does not have a real tradition in the SME sector. On the one hand, small enterprises and family business in general have traditionally not been very open towards external equity financing and are not used to informing transparently about their business.On the other hand, many investors of venture capital and similar forms of equity finance are very reluctant regarding investing their funds in smaller companies, which is more costly than investing bigger amounts in larger companies. Furthermore it is much more difficult to set out of such investments in smaller companies.Even though equity financing will never become the main source of financing for SMEs, it is an important instrument for highly innovative start-ups and fast growing companies and it has therefore to be further developed. UEAPME sees three pillars for such an approach where policy support is needed:Availability of venture capital•The Member States should review their taxation systems in order to create incentives to invest private money in all forms of venture capital.•Guarantee instruments for equity financing should be further developed.Improve the conditions for investing venture capital into SMEs•The development of secondary markets for venture capital investments in SMEs should be supported.•Accounting Standards for SMEs should be revised in order to easetransparent exchange of information between investor and owner-manager.Owner-managers must become more aware about the need for transparency towards investors•SME owners will have to realise that in future access to external finance (venture capital or lending) will depend much more on a transparent and open exchange of information about the situation and the perspectives of their companies.•In order to fulfil the new needs for transparency, SMEs will have to use new information instruments (business plans, financial reporting, etc.) and new management instruments (risk-management, financial management, etc.).外文资料翻译涂敏之会计学 8051208076题目:未来的中小企业融资背景:中小企业融资已经改变未来的经济复苏将取决于能否工艺品,贸易和中小企业利用其潜在的增长和创造就业。

汽车 专业 外文 文献 英文 翻译

汽车 专业 外文 文献 英文 翻译

外文文献原稿和译文原稿A New Type Car -- Hybrid Electric VehicleWith skyrocketing fuel prices and changes in weather patterns, many car manufacturers claimed to develop the kind of vehicles that will increase the mileage and reduce the emissions. Hybrid car is a kind of vehicle which can meet above requirements. A hybrid car features a small fuel-efficient gas engine combined with an electric motor that assists the engine.The reasons of building such a complicated machine are twofold: to reduce tailpipe emissions and to improve mileage. Firstly, hybrid cars are good for the environment. They can reduce smog by 90 percent and they use far less gasoline than conventional cars. Meanwhile, hybrid cars burn less gasoline per mile, so they release fewer greenhouse gases. Secondly, hybrid cars are economical. Hybrid cars, which run on gas and electricity, can get up to 55 to 60 miles per gallon in city driving, while a typical SUV might use three times as much gas for the same distance! There are three reasons can mainly account for that: 1) Hybrid engines are much smaller than those on conventional cars. A hybrid car engine is to accommodate the 99% of driving time when a car is not going up hills or accelerating quickly. When extra acceleration power is needed, it relies on the battery to provide additional force. 2) Hybrid gasoline engine can shut off when the car is stopped and run off their electric motor and battery.3) Hybrid cars often recover braking energy. Electric motors could take the lost kinetic energy in braking and use it to charge the battery. Furthermore, hybrids are better than all-electric cars because hybrid car batteries recharge as you drive so there is no need to plug in. Most electric cars need to be recharged every 50-100miles. Also, most electric cars cannot go faster than 50-60 mph, while hybrids can.Hybrid cars bridge the gap between electric and gasoline-powered cars by traveling further and driving faster and hybrid gas-electric cars are proving to be a feasible alternative at a time of high gas prices. So, in my opinion, hybrid cars will have a bright future.How Does Hybrid Electric Vehicle Work?You probably own a gasoline or diesel-engine car. You may have heard of electric vehicles too. A hybrid vehicle or hybrid electric vehicle (HEV) is a combination of both. Hybrid vehicles utilize two or more sources of energy for propulsion. In the case of HEVs, a combustion engine and an electric motor are used.How it works depends on the type of drive train it has. A hybrid vehicle can either have a parallel or series or parallel-series drive train.Parallel HybridThe parallel hybrid car has a gas tank, a combustion engine, transmission,electric motor, and batteries.A parallel hybrid is designed to run directly from either the combustion engine or the electric motor. It can run using both the engine and the motor. As a conventional vehicle, the parallel hybrid draws its power from the combustion engine which will then drive the transmission that turns the wheels. If it is using the electric motor, the car draws its power from the batteries. The energy from the batteries will then power the electric motor that drives the transmission and turns the wheel.Both the combustion engine and the electric motor are used at the same time during quick acceleration, on steep ascend, or when either the engine or the motor needs additional boost.Since the engine is directly connected to the wheels in a parallel drive train, it eliminates the inefficiency of converting mechanical energy into electrical energy and back. This makes a very effective vehicle to drive on the highway.Series HybridThe series hybrid car also has a gas tank, a combustion engine, transmission, electric motor, and batteries with the addition of the generator. The generator can be the electric motor or it can be another separate component.The series configuration is the simplest among the 3. The engine is not connected to the transmission rather it is connected to the electric motor. This means that the transmission can be driven only by the electric motor which draws its energy from the battery pack, the engine or the generator.A hybrid car with a series drive train is more suited for city driving conditions since the engine will not be subjected to the varying speed demands (stop, go, and idle) that contributes to fuel consumption.Series-Parallel HybridThe series-parallel configuration solves the individual problems of the parallel and series hybrid. By combining the 2 designs, the transmission can be directly connected to the engine or can be separated for optimum fuel consumption. The Toyota Prius and the Ford Escape Hybrid use this technology.Honda’s hybridFor those of you who have toyed with the idea of buying a hybrid but were discouraged by the price, you are not alone. In fact, despite the growing concern for the environment, not to mention the skyrocketing price of gas, hybrid cars still only represent a small percentage of global car sales, and a major reason for this is the cost.Hybrids are considered the wave of the future because they not only reduce emissions, addressing the issue of climate change, but they get great gas mileage, an important consideration with the current price of oil. It should be noted that hybrids can also improve the power of the engine, which compromises any advantages in fuel efficiency and emissions. Whatever the application, however, the technology makes the cars more expensive.Because of this, they are the vehicle of choice for only a small niche of people who can afford them, and they currently enjoy a special status amongst the image conscious celebrity-set. For most average consumers, however, they are not an option.That may soon change.Honda Motor Corporation, one of the largest car manufacturers in the world and a leader in fuel efficient technology, has unveiled it’s plan to introduce a low-cost hybrid by 2009. If they can pull it off, they hope to make the hybrid a more mainstream car that will be more appealing to the general public, with the ultimate goal of achieving greater sales and broader appeal than their current incarnation.This, of course, is making Detroit nervous, and may signal a need for American car makers to start making greener and more fuel efficient vehicles, something they could afford to ignore in the past because hybrid cars weren’t worth their attention (due to such a small market share) while gas-guzzling SUVs have such high profit margins.Honda, meanwhile, has had to confront a growing need to compete with Toyota, which has not only grown to be the world’s largest automaker, but makes the car that has become synonymous with the hybrid movement, the Prius. Honda is therefore faced with the seemingly insurmountable task of challenging Toyota’s dominance in the market.Concurrently, Toyota is racing to lower production costs on the Prius, as well, which would hopefully result in a lower cost to the consumer. All eyes are on a potentially favorable car buyers market in 2009.In the meantime, with even adamant global warming naysayers warming up (no pun intended) to the possibilities of an ecological disaster on the horizon, maybe it’s time that we got over our need to drive huge SUVs and start moderating our fuel consumption.Then again, as gas prices hovering around $4.00 and with no ceiling in sight, we may have little choice in the matter.Engine Operating PrinciplesMost automobile dngines are internal combustion, reciprocating 4-stroke gasoline engines, but other types have been used, including the diesel, the rotary ( Wankel ) , the 2-srtoke, and stratified charge.Reciprocating means up and down or banck and forth, It is the up and down action of a piston in the cylinder blick, or engine block. The blick is an iron or aluminum casting that contains engine cylinders and passges called water jackets for coolant circulation. The top of the block is covered with the cylinder head. Which forms the combustion chanber. The bottom of the block is covered with an oil pan or oil sump.Power is produced by the linear motion of a piston in a cylinder. However, this linear motion must be changed into rotary motion to turn the wheels of cars of trucks. The piston is attached to the top of a connecting rod by a pin, called a piston pin or wrist pin. The bottom of the connecting rod is attached to the crankshaft. The connecting rod transmits the up-and-down motion of the piston to the crankshaft, which changes it into rotary motion.The connecting rod is mounted on the crankshaft with large beaings called rodbearings. Similar bearings, called main bearings, are used to mount the crankshaft in the block. Shown in Fig. 1-1The diameter of the cylinder is called the engine bore. Displacement and compression ratio are two frequently used engine specifications. Displacement indicates engine size, and compression ratio compares the total cylinder volume to compression chamber volume.The term stroke is used to describe the movement of the iston within the cylinder, as well as the distance of piston travel. Depending on the type of engine the operating cycle may require either two or four strokes to complete. The 4-stroke engine is also called Otto cycle engine, in honor of the German engineer, Dr. Nikolaus Otto, who first applied the principle in 1876. In the 4-stroke engine, four strokes of the piston in the cylinder are required to complete one full operating cycle. Each stroke is named after the action it performs intake, compression, power, and exhaust in that order, shown in Fig1-2.1、Intake strokeAs the piston moves down, the vaporized mixture of fuel and air enters the cylinder through open intake valve. To obtain the maximum filling of the cylinder the intake valve opens about 10°before t.b.c., giving 20°overlap. The inlet valve remains open until some 50°after b.d.c. to take advantage of incoming mixture.2、 Compression strokeThe piston turns up, the intake valve closes, the mixture is compressed within the combustion chamber, while the pressure rise to about 1Mpa, depending on various factors including the compression ratio, throttle opening and engine speed. Near the top of the stroke the mixture is ignited by a spark which bridges the gap of the spark plug.3、 Power strokeThe expanding gases of combustion produces a rise in pressure of the gas to some 3.5Mpa, and the piston is forced down in the cylinder. The exhaust valve opens near the bottom of the stroke.4、Exhust strokeThe piston moves back up with the exhaust valve open some 50°before b.d.d., allowing the pressure within the cylinder to fall and to reduce ‘back’pressure on the piston during the exhaust stroke, and the burned gases are pushed out to prepare for the next intake stroke.The intake valve usually opens just before the exhaust stroke. This 4-stroke cycle is continuously repeared in every as long as the engineremains running.A 2-stroke engine also goes through four actions to complete one operating cycle.However, the intake and the compression actions are combined in one seroke, and the power and exhaust actions are combined in the other stroke. The term2-stroke cycle or 2-stroke is preferred to the term 2-cycle, which is really not accurate.In automobile engines, all pistons are attached to a single crankshaft. The more cylinders an engine has, the more power strokes produced for cach revolution. This means that an 8-cylinder engine runs more smoothly bdcause the power atrokes arecloser together in time and in degrees of engine rotation.The cylinders of multi-cylinder automotive engines arranged in one of three ways. 1、Inline engines use a single block of cylinder.Most 4-cylinder and any 6-cylinder engines are of this design. The cylinders do not have to be vertical. They can be inclined either side.2、V-type engines use two equal bands of cylinders, usually inclined 60degrees or 90degrees from the cach other. Most V-type engines have 6 or 8 cylinders, although V-4 and V-12 engines have been built.3、Horizontally opposed or pancake engines have two equal banks of cylinders 180degreeas apart. These space saving engine designs are often air-cooled, and are found in the Chevrolet Carvair, Porsches, Subaus, and V olkswagens. Subaus design is liquid cooled.Late-model V olkswagen vans use a liquid-cooled version of the air cooled VWhorizontally opposed engine.译文新型汽车----混合动力汽车在油价飞涨的今天,汽车制造商被要求发展一种排放低,行驶里程长的汽车。

外文文献

外文文献

英文文献资料外文文献一:Food safety: the shocking truth about the food industrySource: Author: Marion Nestle、Refrigeration technology, pasteurization, pesticides, disease control, these technologies so that safe food into the 20th century, public health's greatest achievements. This book view is that food safety problems also depend on politics. September 2001 events to dispel this view of the doubts about aviation aircraft used by terrorists as a destruction of weapons to civilians and public figures have anthrax spores sent folder of letters, the consequences of these events shows, food, water can easily become a a tool for terrorists, it has also become the federal government for food safety control problem.This chapter will sum up this book referred to in the various food safety problems. Some of them threatened to keep animals healthy, very few will lead to a number of human diseases. Even so, these issues impact on human well-being is deep; large-scale destruction of breeding animals, affecting the livelihood of many people, limiting personal freedom. The 20th century, 90's and early 21st century, an outbreak of mad cow disease and foot and mouth disease Although this is only because of errors caused by the production process, but still brings a lot of destructive. In contrast, bio-terrorism is the deliberate use of biological and chemical substances to achieve their political objectives. For food safety issues,Bio-terrorism extends food safety issues and political outreach; deliberate destruction, excluding any consequences of innocent injury.In this chapter, we will discuss how the rise of bio-terrorism, food safety issues and extend the extension of food safety issues. In the United States, food safety, usually refers to the family food supply reliability. E-mail from the anthrax incident, the food safety issues, also includes safety from biological terrorism. Our discussion will be the beginning of some zoonotic diseases: such as mad cow disease, foot and mouth disease, anthrax. In recent years, these zoonotic diseases harmful to humans is relatively small. Today, for these zoonotic diseases, we are concerned that they may give rise to disease, destruction of food supply system,To become a tool for bio-terrorism aspect. This chapter summarizes the discussion of this book, fromsociety and from a personal point of view what action should be taken to face these issues, as well as food safety issues present and future.The political animal diseasesOne of the consequences of globalization is that of food cross-border long-distance rapid transit, affecting food supply all kinds of disease can easily spread from one country to another country. Animal diseases have a commercial impact, if a country has come to infectious diseases of animals, other countries will refuse to import the kinds of animal meat. The impact of business at the same time there are political consequences.Britain's mad cow disease and foot and mouth disease occurred as a result of beef in the production process caused by mismanagement, compared to the U.S. anthrax letters is a result of vandalism. However, this three kinds of threatening to cause great panic, they are difficult to detect control, can cause severe disease. Moreover, these three kinds of threats against people for the food supply, as well as confidence in the Government.Mad cow is the mid-20th century, 90 of the most popular of a food security crisis, the epidemic is mainly limited to the United Kingdom. With regard to BSE-related issues and our discussion, mainly because of political issues and scientific issues intertwined Among them, public confidence had a great impact. For example, the British Government in the BSE crisis in the practice is also considered to result in distrust of genetically modified food one of the reasons. The beginning of the 20th century, 80 years, no one had heard of the disease, but in 1999, this disease affects at least 175,000 British cattle. The consequences are very serious: 400 million head of livestock were slaughtered, the loss of 70 billion U.S. dollars,Spread to 18 countries worldwide national boycott of British beef. By 2001 only, although "only" 120 people died of the human variant of mad cow disease, it is estimated the death toll will reach 10 million people. Because mad cow disease revealed the modern politics of food safety issues, it is worth detailing.英文文献中文翻译06013618 胡冬敏外文翻译一:作者:玛丽恩·内斯特尔出版时间:2004年11月食品安全:令人震惊的食品行业真相(美)玛丽恩·内斯特尔冷藏技术,巴氏消毒,杀虫剂,疾病控制,这些技术使安全食品成为20世纪公众健康最伟大的成就之一。

外文文献免费范文精选

外文文献免费范文精选

英文原文1:《Professional C# Third Edition》Simon Robinson,Christian Nagel, Jay Glynn, Morgan Skinner, Karli Watson, Bill Evjen. Wiley Publishing, Inc. 2006 Where C# Fits InIn one sense, C# can be seen as being the same thing to programming languages is to the Windows environment. Just as Microsoft has been adding more and more features to Windows and the Windows API over the past decade. Visual Basic andC++ have undergone expansion. Although Visual Basic and C++ have ended up as hugely powerful languages as a result of this, both languages also suffer from problems due to the legacies of how they have evolved.In the case of Visual Basic 6 and earlier, the main strength of the language was the fact that it was simple to understand and didn't make many programming tasks easy, largely hiding the details of the Windows APT and the COM component infrastructure from the developer. The downside to this was that Visual Basic was never truly object-oriented, so that large applications quickly become disorganized and hard to maintain. As well as this, because Visual Basic's syntax was inherited from early versions of BASIC (which, in turn, was designed to be intuitively simple for beginning programmers to understand, rather than lo write large commercial applications), it didn't really lend itself to well-structured or object-oriented programs.C++, on the other hand, has its roots in the ANSI C++ language definition. It isn’t completely ANSI compliant for the simple reason that Microso ft first wrote itsC++ compiler before the ANSI definition had become official, but it conics close. Unfortunately, this has led to two problems. First, ANSI C++ has its roots in a decade-old state of technology, and this shows up in a lack of support for modern 1 外文文献-中文翻译-c#concepts (such as Unicode strings and generating XML documentation), and in some archaic syntax structures designed for the compilers of yesteryear (such as the separation of declaration from definition of member functions). Second, Microsoft has been simultaneously trying to evolve C++ into a language that is designed for high-performance (asks on Windows, and in order to achieve that they've been forced to add a huge number of Microsoft-specific keywords as well as various libraries to the language.The result is that on Windows, the language has become a complete mess. Just ask C++ developers how many definitions for a string they can think of: char*, LPTSTR, string, CString (MFC version), CString (WTL version), wchar_l*, OLECHAR*, and so on.Now completely new environment that is going to involve new extensions to both languages. Microsoft has gotten around this by adding yet more Microsoft-specific keywords to C++, and by completely revamping Visual Basic into Visual a language that retains some of the basic VB syntax but that is so different in design that we can consider it to be, for all practical purposes, a new language. It?s in this context that Microsoft has decided to give developers an alternative—a language designed specifically and designed with a clean slate. Visual C# .NET is the result. Officially, Microsoft describes C# as a ''simple, modern, object-oriented, and type-safe programming language derived from C and C++.” Most independent observers would probably change Chat to '"derived from C, C++, and Java.^ Such descriptions are technically accurate but do little to convey the beauty or elegance of the language. Syntactically, C# is very similar to both C++ and Java, to such 2an extent that many keywords are (he same, and C# also shares the same block structure with braces ({}) to mark blocks of code, and semicolons to separate statements. The first impression of a piece of C# code is that it looks quite like C++ or Java code. Behind that initial similarity, however, C# is a lot easier to learn than C++, and of comparable difficulty to Java. Its design is more in tune with modern developer tools than both of those other languages, and it has been designed to give us, simultaneously, the ease of use of Visual Basic, and the high performance, low-level memory access of C++ if required. Some of the features of C# arc:LI Full support for classes and object-oriented programming, including both interface and implementation inheritance, virtual functions, and operator overloading.□ A consistent and well-defined set of basic types.□ Built-in support for automatic generation of XML documentation.□ Automatic cleanup of dynamically allocated memory.□ The facility to mark classes or methods with user-defined attributes. This can be useful for documentation and can have some effects on compilation (for example, marking methods to be compiled only in debug builds).□ Full access to base class library, as well as easy access to the Windows AP I (if you really need it, which won’t be all that often).□ Pointers and direct memory access are available if required, but the language has been designed in such a way that you can work without them in almost all cases. □ Support for properties and eve nts in the style of Visual Basic.LJ Just by changing the compiler options, you can compile either to an executable or to a library components that can be called up by other code in the same way as 3外文文献-中文翻译-c#ActiveX controls (COM components).LI C# can be used to write dynamic Web pages and XMLWeb services.Most of the above statements, it should be pointed out. do also apply to Visual and Managed C++. The fact that C# is designed from the start to work however, means that its support for the features is both more complete, and offered within the context of a more suitable syntax than for those other languages. While the C# language itself is very similar to Java, there are some improvements: in particular. Java is not designed to work with environment.Before we leave the subject, we should point out a couple of limitations of C#. The one area the language is not designed for is time-critical or extremely high performance code—the kind where you really are worried about whether a loop takes 1.000 or 1,050 machine cycles to run through, and you need to clean up your resources the millisecond they arc no longer needed. C++ is likely to continue to reign supreme among low-level languages in this area. C# lacks certain key facilities needed for extremely high performance apps, including the ability to specify inline functions and destructors that are guaranteed to run at particular points in the code. However, the proportions of applications that fall into this category are very low.4外文文献-中文翻译-c#中文译文1:《C#的优点》C#在某种程度上k可以打作足.NET面向Windows环境的种编程语言。

外文参考文献(带中文翻译)

外文参考文献(带中文翻译)

外文资料原文涂敏之会计学 8051208076Title:Future of SME finance(/docs/pos_papers/2004/041027_SME-finance_final.do c)Background – the environment for SME finance has changedFuture economic recovery will depend on the possibility of Crafts, Trades and SMEs to exploit their potential for growth and employment creation.SMEs make a major contribution to growth and employment in the EU and are at the heart of the Lisbon Strategy, whose main objective is to turn Europe into the most competitive and dynamic knowledge-based economy in the world. However, the ability of SMEs to grow depends highly on their potential to invest in restructuring, innovation and qualification. All of these investments need capital and therefore access to finance.Against this background the consistently repeated complaint of SMEs about their problems regarding access to finance is a highly relevant constraint that endangers the economic recovery of Europe.Changes in the finance sector influence the behavior of credit institutes towards Crafts, Trades and SMEs. Recent and ongoing developments in the banking sector add to the concerns of SMEs and will further endanger their access to finance. The main changes in the banking sector which influence SME finance are:•Globalization and internationalization have increased the competition and the profit orientation in the sector;•worsening of the economic situations in some institutes (burst of the ITC bubble, insolvencies) strengthen the focus on profitability further;•Mergers and restructuring created larger structures and many local branches, which had direct and personalized contacts with small enterprises, were closed;•up-coming implementation of new capital adequacy rules (Basel II) will also change SME business of the credit sector and will increase its administrative costs;•Stricter interpretation of State-Aide Rules by the European Commission eliminates the support of banks by public guarantees; many of the effected banks are very active in SME finance.All these changes result in a higher sensitivity for risks and profits in the finance sector.The changes in the finance sector affect the accessibility of SMEs to finance.Higher risk awareness in the credit sector, a stronger focus on profitability and the ongoing restructuring in the finance sector change the framework for SME finance and influence the accessibility of SMEs to finance. The most important changes are: •In order to make the higher risk awareness operational, the credit sector introduces new rating systems and instruments for credit scoring;•Risk assessment of SMEs by banks will force the enterprises to present more and better quality information on their businesses;•Banks will try to pass through their additional costs for implementing and running the new capital regulations (Basel II) to their business clients;•due to the increase of competition on interest rates, the bank sector demands more and higher fees for its services (administration of accounts, payments systems, etc.), which are not only additional costs for SMEs but also limit their liquidity;•Small enterprises will lose their personal relationship with decision-makers in local branches –the credit application process will become more formal and anonymous and will probably lose longer;•the credit sector will lose more and more its “public function” to provide access to finance for a wide range of economic actors, which it has in a number of countries, in order to support and facilitate economic growth; the profitability of lending becomes the main focus of private credit institutions.All of these developments will make access to finance for SMEs even more difficult and / or will increase the cost of external finance. Business start-ups and SMEs, which want to enter new markets, may especially suffer from shortages regarding finance. A European Code of Conduct between Banks and SMEs would have allowed at least more transparency in the relations between Banks and SMEs and UEAPME regrets that the bank sector was not able to agree on such a commitment.Towards an encompassing policy approach to improve the access of Crafts, Trades and SMEs to financeAll analyses show that credits and loans will stay the main source of finance for the SME sector in Europe. Access to finance was always a main concern for SMEs,but the recent developments in the finance sector worsen the situation even more. Shortage of finance is already a relevant factor, which hinders economic recovery in Europe. Many SMEs are not able to finance their needs for investment.Therefore, UEAPME expects the new European Commission and the new European Parliament to strengthen their efforts to improve the framework conditions for SME finance. Europe’s Crafts, Trades and SMEs ask for an encompassing policy approach, which includes not only the conditions for SMEs’ access to lending, but will also strengthen their capacity for internal finance and their access to external risk capital.From UEAPM E’s point of view such an encompassing approach should be based on three guiding principles:•Risk-sharing between private investors, financial institutes, SMEs and public sector;•Increase of transparency of SMEs towards their external investors and lenders;•improving the regulatory environment for SME finance.Based on these principles and against the background of the changing environment for SME finance, UEAPME proposes policy measures in the following areas:1. New Capital Requirement Directive: SME friendly implementation of Basel IIDue to intensive lobbying activities, UEAPME, together with other Business Associations in Europe, has achieved some improvements in favour of SMEs regarding the new Basel Agreement on regulatory capital (Basel II). The final agreement from the Basel Committee contains a much more realistic approach toward the real risk situation of SME lending for the finance market and will allow the necessary room for adaptations, which respect the different regional traditions and institutional structures.However, the new regulatory system will influence the relations between Banks and SMEs and it will depend very much on the way it will be implemented into European law, whether Basel II becomes burdensome for SMEs and if it will reduce access to finance for them.The new Capital Accord form the Basel Committee gives the financial market authorities and herewith the European Institutions, a lot of flexibility. In about 70areas they have room to adapt the Accord to their specific needs when implementing it into EU law. Some of them will have important effects on the costs and the accessibility of finance for SMEs.UEAPME expects therefore from the new European Commission and the new European Parliament:•The implementation of the new Capital Requirement Directive will be costly for the Finance Sector (up to 30 Billion Euro till 2006) and its clients will have to pay for it. Therefore, the implementation – especially for smaller banks, which are often very active in SME finance –has to be carried out with as little administrative burdensome as possible (reporting obligations, statistics, etc.).•The European Regulators must recognize traditional instruments for collaterals (guarantees, etc.) as far as possible.•The European Commission and later the Member States should take over the recommendations from the European Parliament with regard to granularity, access to retail portfolio, maturity, partial use, adaptation of thresholds, etc., which will ease the burden on SME finance.2. SMEs need transparent rating proceduresDue to higher risk awareness of the finance sector and the needs of Basel II, many SMEs will be confronted for the first time with internal rating procedures or credit scoring systems by their banks. The bank will require more and better quality information from their clients and will assess them in a new way. Both up-coming developments are already causing increasing uncertainty amongst SMEs.In order to reduce this uncertainty and to allow SMEs to understand the principles of the new risk assessment, UEAPME demands transparent rating procedures –rating procedures may not become a “Black Box” for SMEs:•The bank should communicate the relevant criteria affecting the rating of SMEs.•The bank should inform SMEs about its assessment in order to allow SMEs to improve.The negotiations on a European Code of Conduct between Banks and SMEs , which would have included a self-commitment for transparent rating procedures by Banks, failed. Therefore, UEAPME expects from the new European Commission and the new European Parliament support for:•binding rules in the framework of the new Capital Adequacy Directive, which ensure the transparency of rating procedures and credit scoring systems for SMEs;•Elaboration of national Codes of Conduct in order to improve the relations between Banks and SMEs and to support the adaptation of SMEs to the new financial environment.3. SMEs need an extension of credit guarantee systems with a special focus on Micro-LendingBusiness start-ups, the transfer of businesses and innovative fast growth SMEs also depended in the past very often on public support to get access to finance. Increasing risk awareness by banks and the stricter interpretation of State Aid Rules will further increase the need for public support.Already now, there are credit guarantee schemes in many countries on the limit of their capacity and too many investment projects cannot be realized by SMEs.Experiences show that Public money, spent for supporting credit guarantees systems, is a very efficient instrument and has a much higher multiplying effect than other instruments. One Euro form the European Investment Funds can stimulate 30 Euro investments in SMEs (for venture capital funds the relation is only 1:2).Therefore, UEAPME expects the new European Commission and the new European Parliament to support:•The extension of funds for national credit guarantees schemes in the framework of the new Multi-Annual Programmed for Enterprises;•The development of new instruments for securitizations of SME portfolios;•The recognition of existing and well functioning credit guarantees schemes as collateral;•More flexibility within the European Instruments, because of national differences in the situation of SME finance;•The development of credit guarantees schemes in the new Member States;•The development of an SBIC-like scheme in the Member States to close the equity gap (0.2 – 2.5 Mio Euro, according to the expert meeting on PACE on April 27 in Luxemburg).•the development of a financial support scheme to encourage the internalizations of SMEs (currently there is no scheme available at EU level: termination of JOP, fading out of JEV).4. SMEs need company and income taxation systems, which strengthen their capacity for self-financingMany EU Member States have company and income taxation systems with negative incentives to build-up capital within the company by re-investing their profits. This is especially true for companies, which have to pay income taxes. Already in the past tax-regimes was one of the reasons for the higher dependence of Europe’s SMEs on bank lending. In future, the result of rating will also depend on the amount of capital in the company; the high dependence on lending will influence the access to lending. This is a vicious cycle, which has to be broken.Even though company and income taxation falls under the competence of Member States, UEAPME asks the new European Commission and the new European Parliament to publicly support tax-reforms, which will strengthen the capacity of Crafts, Trades and SME for self-financing. Thereby, a special focus on non-corporate companies is needed.5. Risk Capital – equity financingExternal equity financing does not have a real tradition in the SME sector. On the one hand, small enterprises and family business in general have traditionally not been very open towards external equity financing and are not used to informing transparently about their business.On the other hand, many investors of venture capital and similar forms of equity finance are very reluctant regarding investing their funds in smaller companies, which is more costly than investing bigger amounts in larger companies. Furthermore it is much more difficult to set out of such investments in smaller companies.Even though equity financing will never become the main source of financing for SMEs, it is an important instrument for highly innovative start-ups and fast growing companies and it has therefore to be further developed. UEAPME sees three pillars for such an approach where policy support is needed:Availability of venture capital•The Member States should review their taxation systems in order to create incentives to invest private money in all forms of venture capital.•Guarantee instruments for equity financing should be further developed.Improve the conditions for investing venture capital into SMEs•The development of secondary markets for venture capital investments in SMEs should be supported.•Accounting Standards for SMEs should be revised in order to ease transparent exchange of information between investor and owner-manager.Owner-managers must become more aware about the need for transparency towards investors•SME owners will have to realise that in future access to external finance (venture capital or lending) will depend much more on a transparent and open exchange of information about the situation and the perspectives of their companies.•In order to fulfil the new needs for transparency, SMEs will have to use new information instruments (business plans, financial reporting, etc.) and new management instruments (risk-management, financial management, etc.).外文资料翻译涂敏之会计学 8051208076题目:未来的中小企业融资背景:中小企业融资已经改变未来的经济复苏将取决于能否工艺品,贸易和中小企业利用其潜在的增长和创造就业。

研究生外文文献翻译--中英完整版

研究生外文文献翻译--中英完整版

Discussion about the application of the anchor bar on theslope constructionFu Ming Fu , Zhang TianAbstract:There are some advantages in strengthening slope with the anchor bar, such as low project cost, convenient for construction and so on. It not only meets the requirement of the reliability of the construction, but also is economic and reasonable for the construction.Key words: anchor bar; slope; strengthening1.IntroductionAnchor technique uses strata geotechnical’s shear strength around bolt to deliver structures pulling force or keep strata of the excavation own stability. Due to the use of the anchor rod, Anchor strata produce compressive zone and have reinforcement effect to strata, can enhance the strength of strata, improve mechanical properties of strata, make structure and stratum together formed a kind of work together complex. Anchor system can effectively sustain tension and shear, improve shear strength of the potential sliding surface, so it can effectively prevent slope to produce sliding damage.Fig 1 after excavation of the slope2.Project profileThe length of a slope is about 60m, the most slope height is about 23m,the angle up to 50°~ 75°, a five-layer frame structure buildings is far from about 1.5 to 4m at its base edge, its foundation is artificial bored pile and its bearing stratum is in weathered phyllite. Due to the strong weathering of rocks, it was chunky, loosely structured, multi-muddy filling. It has residual slope deposits of silty clay overlying and local folder with a pulpy, low strength. Slope hadcollapsed at various locations, it is vary dangerous to the building, so we need to reinforce the slope, and we use stone concrete retaining wall and bolt to support it.3.Bolt retaining and protecting design3.1Bolt design(1)all formation of anchor use whole length bond-type, the binder materials are ordinary cement mortar, the mortar strength grade is M30, the anchor length L is 10 meters, the slope height h is 9 meters. Anchoring section length is 5m.(2)According to the construction condition and the needs of the process, the layout form of anchor use quincunx, and in order to make the anchoring force in the role of surface rock surface with uniform, the two adjacent line bolts should be staggered arrangement.(3)The anchor’s number according to /3.24 per meter to calculation, the anchor length is L, a tolal of 252. The diameter of drilling holes is φ90,the number of drill according to (L-0.1)m per hole to calculation, M30 grout number according to average 0.052m3per hole to calculation.(4)The two adjacent rows vertical spacing of anchor take 2.55m, horizontal spacing take 2.55m. The dip angle of anchor: with the angle of horizontal line is 20°, and drilling down with this Angle.(5)Anchor use the steel bar, which is HRB400 level, 28mm diameter.3.2Anchor calculation(1)The calculation of lateral geotechnical pressure[1][2]When the supporting structure to leave in rock and earth mass direction migration until to the limit equilibrium state, the geotechnical pressure which is role in supporting structure called active geotechnical pressure. Its calculation method is as follows:For the slope which has no flare structure surface, generally speaking, failure is controled by rock mass strength, the calculation formula is same to the active soil pressure, but cohesive force C take zero, internal friction angle ϕuse eϕ(rock mass equivalent internal friction angle) instead of, according to the standard to selection; rupture angle is 45°+ϕ/2(ϕis rock mass internal friction angle, is estimationed by haircut at the standard of rock mass internal friction angle, reduction factor according to the standard to selection).According to the engineering survey, active rock pressure can calculation as follows:(2)the calculation of anchor tension design value a Q ak N N γ= (1)(2) In the formula: a N is anchor tension design value; ak N is anchor tension standard value; Q γis partial load factor, take 1.3; tk H is the horizontal tension standard value of anchor; αis the dip angle of anchor.Through the calculation, ak N =112.3kN a N =145.99kN(3)the calculation of anchor steel section area(3) In the formula: S A is the steel section area of anchor; ογ is slope engineering importance coefficient(the slope engineering importance coefficient of this project is level 1, take 1.1); 2ξis the tensile working conditions coefficient of anchor bar ( permanent anchor take 0.69, temporary anchor take 0.92); y f is the tensile strength design value of anchor bar(standard value k y f =400a MP , design value y f =360a MP ).According to the calculation, S A ≥0.5883210m -⨯,choose level 3 steel of 1φ28mm,S A =0.6153210m -⨯.(4)The calculation of anchorage body and rock mass anchoring lengthanchoring length should not only meet the requirements which the bond force of formation on mortar and the bond stress of mortar on steel, but also meet the requirements that the Structure design codes the Minimum anchoring length.(4) In the formula: a l is the anchoring length; D is the diameter of anchorage body; rb f is the bond strength eigenvalue of layer and anchorage body, through the experiment or local experience sure, or according to the standard to selection ( this engineering ’s rock mass uniaxial compressive 2222111209tan (45)2090.217175.77/2222e a aE H K kN m ϕγ︒==⨯⨯⨯-=⨯⨯⨯=cos tkak H N α=2a S yNA f ογξ≥1ak a rbN l Df ξπ≥strength is 7.46a MP , belong to soft rock, rock mass structural plane development, rb f take 300a KP );1ξis the bond working conditions coefficient of anchorage body and layer (permanent anchor take 1.00).According to the calculation, a l ≥4.3m, take a l =5.0m.(5)The anchoring length between anchor steel and anchor mortara l ≥ (5) In the formula: a l is the anchoring length between steel and mortar; d is the diameter of anchor bar; n is the number of steel;b f is the bond strength design value between steel and anchor mortar, through the experiment sure, or according to the standard take 2.40; 3ξ is the working conditions coefficient of steel and mortar bond strength(permanent anchor take 0.60). According to the calculation, a l ≥2.1m ,take a l =5.0m.3.3 The construction technology and key points of anchorThe anchor ’s construction technology is as follows: build-up scaffold ——excavate and clear up the slope surface ——measures to fix position ——drill hole ——washing hole ——bolt put in a certain place ——grout ——colligation the end of the anchor ——flushing the slope surface ——pouring frame space ——Spray seed(1)This slope belong to rocky slope, after excavate the slope 10 cm to the underside of the frame space, set bolt and pouring frame space, then spray grass or seeds after borrowed soil 20 cm in the frame space.(2)the slope should be payed attention to clean up, when construction. The anchor should be placed after wash hole, then put pressure (0.4MPa) and grout. After the mortar fully solidification, colligation steel, cast-in-place reinforced concrete frame space, bend the end of the anchor and bind point by point with the skeleton steel.(3)Before drilling, the hole should be measured to fix position and then do mark. Pitch deviation is less than 150mm, hole depth error is less than 50mm. Try not remold the surrounding rock, when drill. Before Put the anchor, it should be attentioned that blow wash clean the water of the hole and rock powder and so on, and rust removal the body of rod. When grouting, builders 3a bN n df ογξπshould attention the grouting pressure and mortar ratio.Fig 2 anchor field construction drawing4.ConclusionIt is economical to reinforcement slope with bolt, and use the normal equipment, It is not only achieve safe and also economy and rational.(1) Today bolt technology is widely used in the project. It is an effective reinforcement measures to constraints sliding soil with the combining of bolt and concrete slope protection.(2) We must be sure to do geological exploration work of the slope to find out the nature of the rock and hydrogeological situation before reinforcing slope by grouting bolt.(3) Due to the factors of engineering geological conditions, grouting pressure and construction technology, we should be given adequate attention to the quality of construction.Reference[1]Technical code for building slope engineering (JGJ 120-99). The People's Republic nationalstandards. Beijing: China Architecture & Building PRESS.[2] Ying-Ren Zheng, Zu-Yu Chen etc. Engineering Treatment of Slope & Landslide [M]. Beijing:China Communications Press,2007[3] LuoZhenHai. Talk shallowly the application of the anchor at the slope reinforcement[J]. FujianConstruction Science & Technology,2010,06:15-16浅谈锚杆技术在边坡工程中的应用 1.引言锚杆技术是利用锚杆周围地层岩土的抗剪强度来传递结构物的拉力或保持地层开挖面的自身稳定。

建筑类外文文献及中文翻译

建筑类外文文献及中文翻译

forced concrete structure reinforced with anoverviewReinSince the reform and opening up, with the national economy's rapid and sustained development of a reinforced concrete structure built, reinforced with the development of technology has been great. Therefore, to promote the use of advanced technology reinforced connecting to improve project quality and speed up the pace of construction, improve labor productivity, reduce costs, and is of great significance.Reinforced steel bars connecting technologies can be divided into two broad categories linking welding machinery and steel. There are six types of welding steel welding methods, and some apply to the prefabricated plant, and some apply to the construction site, some of both apply. There are three types of machinery commonly used reinforcement linking method primarily applicable to the construction site. Ways has its own characteristics and different application, and in the continuous development and improvement. In actual production, should be based on specific conditions of work, working environment and technical requirements, the choice of suitable methods to achieve the best overall efficiency.1、steel mechanical link1.1 radial squeeze linkWill be a steel sleeve in two sets to the highly-reinforced Department with superhigh pressure hydraulic equipment (squeeze tongs) along steel sleeve radial squeeze steel casing, in squeezing out tongs squeeze pressure role of a steel sleeve plasticity deformation closely integrated with reinforced through reinforced steel sleeve and Wang Liang's Position will be two solid steel bars linkedCharacteristic: Connect intensity to be high, performance reliable, can bear high stress draw and pigeonhole the load and tired load repeatedly.Easy and simple to handle, construction fast, save energy and material, comprehensive economy profitable, this method has been already a large amount of application in the project.Applicable scope : Suitable for Ⅱ, Ⅲ, Ⅳgrade reinforcing bar (including welding bad reinfor cing bar ) with ribbing of Ф 18- 50mm, connection between the same diameter or different diameters reinforcing bar .1.2must squeeze linkExtruders used in the covers, reinforced axis along the cold metal sleeve squeeze dedicated to insert sleeve Lane two hot rolling steel drums into a highly integrated mechanical linking methods.Characteristic: Easy to operate and joining fast and not having flame homework , can construct for 24 hours , save a large number of reinforcing bars and energy. Applicable scope : Suitable for , set up according to first and second class antidetonation requirement -proof armored concrete structure ФⅡ, Ⅲgrade reinforcing bar with ribbing of hot rolling of 20- 32mm join and construct live.1.3 cone thread connectingUsing cone thread to bear pulled, pressed both effort and self-locking nature, undergo good principles will be reinforced by linking into cone-processing thread at the moment the value of integration into the joints connecting steel bars.Characteristic: Simple , all right preparatory cut of the craft , connecting fast, concentricity is good, have pattern person who restrain from advantage reinforcing bar carbon content.Applicable scope : Suitable for the concrete structure of the industry , civil buil ding and general structures, reinforcing bar diameter is for Фfor the the 16- 40mm one Ⅱ, Ⅲgrade verticality, it is the oblique to or reinforcing bars horizontal join construct live.conclusionsThese are now commonly used to connect steel synthesis methods, which links technology in the United States, Britain, Japan and other countries are widely used. There are different ways to connect their different characteristics and scope of the actual construction of production depending on the specific project choose a suitable method of connecting to achieve both energy conservation and saving time limit for a project ends.钢筋混凝土构造中钢筋连接综述改革开放以来,伴随国民经济旳迅速、持久发展,多种钢筋混凝土建筑构造大量建造,钢筋连接技术得到很大旳发展。

外文文献翻译原文+译文

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。

(完整word版)外文文献及翻译doc

(完整word版)外文文献及翻译doc

Criminal Law1.General IntroductionCriminal law is the body of the law that defines criminal offenses, regulates the apprehension, charging, and trial of suspected offenders,and fixes punishment for convicted persons. Substantive criminal law defines particular crimes, and procedural law establishes rules for the prosecution of crime. In a democratic society, it is the function of the legislative bodies to decide what behavior will be made criminal and what penalties will be attached to violations of the law.Capital punishment may be imposed in some jurisdictions for the most serious crimes. And physical or corporal punishment may still be imposed such as whipping or caning, although these punishments are prohibited in much of the world. A convict may be incarcerated in prison or jail and the length of incarceration may vary from a day to life.Criminal law is a reflection of the society that produce it. In an Islamic theocracy, such as Iran, criminal law will reflect the religious teachings of the Koran; in an Catholic country, it will reflect the tenets of Catholicism. In addition, criminal law will change to reflect changes in society, especially attitude changes. For instance, use of marijuana was once considered a serious crime with harsh penalties, whereas today the penalties in most states are relatively light. As severity of the penaltieswas reduced. As a society advances, its judgments about crime and punishment change.2.Elements of a CrimeObviously, different crimes require different behaviors, but there are common elements necessary for proving all crimes. First, the prohibited behavior designated as a crime must be clearly defined so that a reasonable person can be forewarned that engaging in that behavior is illegal. Second, the accused must be shown to have possessed the requisite intent to commit the crime. Third, the state must prove causation. Finally, the state must prove beyond a reasonable doubt that the defendant committed the crime.(1) actus reusThe first element of crime is the actus reus.Actus is an act or action and reus is a person judicially accused of a crime. Therefore, actus reus is literally the action of a person accused of a crime. A criminal statute must clearly define exactly what act is deemed “guilty”---that is, the exact behavior that is being prohibited. That is done so that all persons are put on notice that if they perform the guilty act, they will be liable for criminal punishment. Unless the actus reus is clearly defined, one might not know whether or not on e’s behavior is illegal.Actus reus may be accomplished by an action, by threat of action,or exceptionally, by an omission to act, which is a legal duty to act. For example, the act of Cain striking Abel might suffice, or a parent’s failure to give to a young child also may provide the actus reus for a crime.Where the actus reus is a failure to act, there must be a duty of care. A duty can arise through contract, a voluntary undertaking, a blood relation, and occasionally through one’s official position. Duty also can arise from one’s own creation of a dangerous situation.(2)mens reaA second element of a crime is mens rea. Mens rea refers to an individual’s state of mind when a crime is committed. While actus reus is proven by physical or eyewitness evidence, mens rea is more difficult to ascertain. The jury must determine for itself whether the accused had the necessary intent to commit the act.A lower threshold of mens rea is satisfied when a defendant recognizes an act is dangerous but decides to commit it anyway. This is recklessness. For instance, if Cain tears a gas meter from a wall, and knows this will let flammable gas escape into a neighbor’s house, he could be liable for poisoning. Courts often consider whether the actor did recognise the danger, or alternatively ought to have recognized a danger (though he did not) is tantamount to erasing intent as a requirement. In this way, the importance of mens rea hasbeen reduced in some areas of the criminal law.Wrongfulness of intent also may vary the seriousness of an offense. A killing committed with specific intent to kill or with conscious recognition that death or serious bodily harm will result, would be murder, whereas a killing affected by reckless acts lacking such a consciousness could be manslaughter.(3)CausationThe next element is causation. Often the phrase “but for”is used to determine whether causation has occurred. For example, we might say “Cain caused Abel”, by which we really mean “Cain caused Abel’s death. ”In other words, ‘but for Cain’s act, Abel would still be alive.” Causation, then, means “but for” the actions of A, B would not have been harmed. In criminal law, causation is an element that must be proven beyond a reasonable doubt.(4) Proof beyond a Reasonable DoubtIn view of the fact that in criminal cases we are dealing with the life and liberty of the accused person, as well as the stigma accompanying conviction, the legal system places strong limits on the power of the state to convict a person of a crime. Criminal defendants are presumed innocent. The state must overcome this presumption of innocence by proving every element of the offense charged against the defendant beyond a reasonable doubt to thesatisfaction of all the jurors. This requirement is the primary way our system minimizes the risk of convicting an innocent person.The state must prove its case within a framework of procedural safeguards that are designed to protect the accused. The state’s failure to prove any material element of its case results in the accused being acquitted or found not guilty, even though he or she may actually have committed the crime charged.3. Strict LiabilityIn modern society, some crimes require no more mens rea, and they are known as strict liability offenses. For in stance, under the Road Traffic Act 1988 it is a strict liability offence to drive a vehicle with an alcohol concentration above the prescribed limit.Strict liability can be described as criminal or civil liability notwithstanding the lack mens rea or intent by the defendant. Not all crimes require specific intent, and the threshold of culpability required may be reduced. For example, it might be sufficient to show that a defendant acted negligently, rather than intentionally or recklessly.1. 概述刑法是规定什么试犯罪,有关犯罪嫌疑人之逮捕、起诉及审判,及对已决犯处以何种刑罚的部门法。

外文文献及外文翻译 1

外文文献及外文翻译 1

The Stereo Garage1.1 An overview of the stereo garageVehicles parked nowhere is the problem of the urban social, economic and transport development to a certain extent the result, Garage Equipment development in foreign countries, especially in Japan nearly 30-40 years. Whether technically or in terms of experience had been a success. China is also in the beginning of the 1990s developed mechanical parking equipment, which was 10 years in the past. Because a lot of new residents in the district with the ratio of 1:1. To address the size of parking spaces for tenants and business areas contradictions 3D mechanical parking equipment with an average size of a small motorcycle's unique characteristics, the majority of users have been accepted.Compared with the traditional natural underground garage, Machinery garage demonstrates its superiority in many respects. First, the mechanical garage has a prominent section of superiority. Past due to the underground garage must elapse enough lanes, the average car will occupy an area of 40 square meters, If the use of double-mechanical garage, which would enable ground to improve the utilization rate of around 80% to 90%, If using ground multi-storey (21 storey), three-dimensional garage, 50 square meters of land area will be placed on the 40 cars, which can greatly save the limited land resources, Civil and save development costs.To underground garage, Mechanical garage can be more effective to ensure personal and vehicle safety in the garage or car kept prospective location, the entire electronic control equipment would not operate. It should be said that the mechanical garage from the management can do a thorough separation of people and vehicles.In the underground garage using mechanical parking, it also can remove the heating ventilation; therefore, Operation of the power consumption than workers in the management of underground garage is much lower. Mechanical garage don't usually do complete system, but as a single machine containers. This will give full play to its small space, the advantages of decentralized, Each of the residential areas or groups downstairs to make a complete circuit can be set up random mechanicalparking building. This garage of the district can solve the shortage of parking difficulty in providing convenient conditions right now.Currently, three-dimensional garage mainly in the following forms: lifting and transferring,aisle stacking garage, vertical garage, vertical cycle, box-level cycle, the level of circulating round.1.1.1 Lifting and transferringLifting and transferring Garage modular design, each module can be designed into two, three, four levels, the five-story, semi-submerged in various forms, such as the number of parking spaces from a few to hundreds. Three-dimensional garage applies to the ground and underground car parks, configuration flexibility and cost is low.1. Product features:1) Save land, the configuration flexibility, and shorter construction period.2) Low prices, firefighting and exterior decoration, with a total investment on small foundations.3) Use automatic control, simple structure, safe and reliable.4) Access to a quick, short waiting time.5) Run a smooth, low noise.6) Applies to commercial, offices, and residential quarters supporting the use of car parks.2. Safety devices: anti-dropping device, a photoelectric sensor, spacing protectors, emergency stop switch.1.1.2 Aisle stacking garageAisle stacking garage used as a stacking machine tool access vehicles. All vehicles are stacking machine access, so the technical requirements for stacker higher, a single stacker cost is higher. So aisle stacking apply to the parking garage needs a few more customers.1.1.3 Vertical GarageVertical Garage Elevator similar to the principle that both sides of the hoist layout spaces. Generally need a ground vehicle rotary tables can be saved by the driver away. Vertical Garage generally higher high (tens of meters), safety equipment, Installation precision machining requirements are very high, high cost, but has the smallest area.1.1.4 Vertical cycleProduct features:1) covers an area of small; two berths area can stop 6-10 vehicles.2) The decoration can be added only roof, fire hydrants available.3) Low prices, foundation, external decoration, fire and other small investment, short construction periods.4) Use automatic control, safe and reliable operation.2.2.1 The stereo garage automatic control systemThe modern large-scale building mainstream is intelligent mansion and community. So, automated parking equipment or garage automatic control system will become intelligent mansion and an important part of community. Simple, fast, easy to use, safe, reliable, and less maintenance, to provide users with a safe, easy to use environment, This is auto-parking feature of the basic equipment. All parking equipment operating conditions, vehicles parked in time, vehicle storage Malaysia, garage storage capacity. Vehicles kept high and low peaks, and other information can be transmitted through the network of intelligent control center through intelligent control center operator, and the broadcasting system and the management office of the Division linked related to early release control, management information, thus achieving all the intelligent management. Building and the Community through the intelligent control of the center could also associate with social networking functions. Information released to the collection coming out or expands utilization of the garage social and economic benefits. This will be the automation of the development direction of the garage. Solid Garage automation control system include the following five major subsystems: automatic toll collection management system automatic access systems for remote diagnosis system, automatic Gate, control security system.Subsystems are more unified control of the central control room, for customers planning Garage form of management, Published garage inventory capacity, traffic control program.2.1.1 Automatic Toll Management SystemAutomatic charge adopts contactless IC card. IC card points long-term card and the stored-card. For fixed users, the issue of long-term cards, the cost of fixed users pays management fees paid together; on the temporary users, issue stored-value cards, namely: the user feespaid cards exist within each parking card reader automatically deducted from the cost.2.1.2 Automatic vehicle access systemAutomatic vehicle access system is generally controlled by small PLC. Including the identification card number and mobile disc contains two cars process. Users enter the garage at the entrance to Swiping cards, reader data automatically transmitted to the PLC control system, PLC system through the judgment card number and automatically set the corresponding site mobile trucks and vehicles to the handover location, the garage door opened, shorten the time access to cars. Truck drivers light signals in accordance with the guidelines created only when vehicles parked in a safe location, Parking will be normal light-Kai. Access car after the completion of the garage doors shut down automatically. Mobile site contains car, the system in strict accordance with the various signal detection mobile state, including long signal detection, Detection in place, the position detection limit, officers hit detection, emergency stop signal detection. If cars are running plate is not in place or vehicle length in excess of the permitted length of the garage, all vehicles disc will contain no action, If detected emergency stop signal to stop all action until the emergency stop signal disappeared. Above signals are hardware signals, in addition, the software can also be installed to control signal protection, such as the protection of the time, to ensure that the damage due to hardware failure to signal equipment and the main guarantee for the safety of vehicles.2.1.3 Remote diagnosis systemControllers can spot card, hubs and other network equipment and control center connected to the LAN, MODEN through remote management, monitoring the operation of the scene, when the scene failure, in the control center can be addressed to facilitate the management, e-office security personnel.2.1.4 Automatic GateIn the garage entrance of the no-contact reader, and the Gate of coil users in the garage entrances Swiping cards, the system automatically discriminates validity of the card, if valid, the Gateopen automatically, through induction coils, Automatic self-closing fence; If invalid, the Gate is not open, and sound and light alarm.2.1.5 Monitoring security systemMonitoring security system is in the central control room for monitoring and controlling the operation of the garage scene conditions. It has motion detection, license plate recognition, network connections, different types of alarm systems linkage, and other functions, can be achieved unguarded.System catalog:Video monitoring function : the garage entrances, and the duty, the main segments within the garage installation focusing cameras, On the larger spaces installation spherical platforms, in order to achieve all-round garage on real-time monitoring. If the garage light conditions of the poor would use black-and-white cameras.Motion Detection functions: setting up the night in the garage of motion detection region, detecting when there are a moving target, Motion Detection and Alarm function remind staffs.LPR functions: it can set up the garage light vehicle license plates, vehicle. When the light vehicles entering the garage regional surveillance, the system automatically cross-referenced with images of a very odd situation, issued a warning signal and automatic switching and record their images.Alarm linkage functions: all can move even the police mainframe, if activated Relay acousto-optic warning issued notice of security personnel to voluntarily disarm Gate interception of vehicular access.Digital video functions : it with a continuous record of what happened in the garage, can be synchronized intervals over images arbitrary choice of the overall image to enlarge and local amplification, recording, playback, backup can be conducted all kinds of information.Reportedly, has begun an increasing number of residential quarters began to use a mechanical garage. Taking into account the cost and maintenance, the majority of the district is a multi-storey lifting and transferring parking equipment, mass storage mechanical garage also rarely. Lifting and transferring Garage Equipment parking flow indicate the following:1、The sense of light yellow instructions garage operationRed lamp was ongoing operating instructions, please wait; Green light is currently no operating instructions, can operate; yellow light instructions were to fail, the garage can not work.2、The operationDrivers of vehicles enter from the garage entrance. At the entrance of non-contact sensors Reader former regional shaken following their IC cards, induction process completed, the fence automatically rises driver drove into the garage. The fence shut down automatically after vehicles entering. Card is the controller to read spaces, corresponding to the parking garage containing cars moved to the site automatically transfer vehicle location, Automatic garage door open units. Car drivers entering and parking in place, Latin hand brake, alighted out of the garage, using IC cards in the garage exit Huang about IC cards Garage door modules to shut down automatically. Completed deposit truck operators.3、Collect the car operationDrivers entering the garage at the entrance to the non-contact sensors Reader former regional shaken following their IC cards Controller automatically read spaces, corresponding to the parking garage containing cars moved to the site automatically transfer vehicle location, Automatic garage door open modules, drivers entering the garage and drive out, in the garage exit of the automatic reader before induction regional dazzle your own IC cards, sensors finished, the reader receive information, Host controller automatically recorded, prepaid, automatically raising the fence, the driver drove the playing field, appeared after fencing to shut down automatically. Meanwhile, Controller automatically read spaces, corresponding to the garage door unit shut down automatically. Vehicle operation finished.The garage has a complete self-protection device in the course of operation. A series of photoelectric switches, proximity switches, trip switches and other vehicles on site contains accurate operation in place to play a decisive role; falling unique defense installations, broken rope warning device, speeding vehicle protection device to protect the security role played. Detection of long vehicles, vehicle parking is not in place detection, and personnel into a detection signal of vehicles and the safety play a decisive role.翻译立体车库1.1 立体车库概述车辆无处停放的问题是城市的社会、经济、交通发展到一定程度产生的结果,立体停车设备的发展在国外,尤其在日本已有近3040年的历史,无论在技术上还是在经验上均已获得了成功。

外文文献及翻译

外文文献及翻译

((英文参考文献及译文)二〇一六年六月本科毕业论文 题 目:STATISTICAL SAMPLING METHOD, USED INTHE AUDIT学生姓名:王雪琴学 院:管理学院系 别:会计系专 业:财务管理班 级:财管12-2班 学校代码: 10128 学 号: 201210707016Statistics and AuditRomanian Statistical Review nr. 5 / 2010STATISTICAL SAMPLING METHOD, USED IN THE AUDIT - views, recommendations, fi ndingsPhD Candidate Gabriela-Felicia UNGUREANUAbstractThe rapid increase in the size of U.S. companies from the earlytwentieth century created the need for audit procedures based on the selectionof a part of the total population audited to obtain reliable audit evidence, tocharacterize the entire population consists of account balances or classes oftransactions. Sampling is not used only in audit – is used in sampling surveys,market analysis and medical research in which someone wants to reach aconclusion about a large number of data by examining only a part of thesedata. The difference is the “population” from which the sample is selected, iethat set of data which is intended to draw a conclusion. Audit sampling appliesonly to certain types of audit procedures.Key words: sampling, sample risk, population, sampling unit, tests ofcontrols, substantive procedures.Statistical samplingCommittee statistical sampling of American Institute of CertifiedPublic Accountants of (AICPA) issued in 1962 a special report, titled“Statistical sampling and independent auditors’ which allowed the use ofstatistical sampling method, in accordance with Generally Accepted AuditingStandards (GAAS). During 1962-1974, the AICPA published a series of paperson statistical sampling, “Auditor’s Approach to Statistical Sampling”, foruse in continuing professional education of accountants. During 1962-1974,the AICPA published a series of papers on statistical sampling, “Auditor’sApproach to Statistical Sampling”, for use in continuing professional educationof accountants. In 1981, AICPA issued the professional standard, “AuditSampling”, which provides general guidelines for both sampling methods,statistical and non-statistical.Earlier audits included checks of all transactions in the period coveredby the audited financial statements. At that time, the literature has not givenparticular attention to this subject. Only in 1971, an audit procedures programprinted in the “Federal Reserve Bulletin (Federal Bulletin Stocks)” includedseveral references to sampling such as selecting the “few items” of inventory.Statistics and Audit The program was developed by a special committee, which later became the AICPA, that of Certified Public Accountants American Institute.In the first decades of last century, the auditors often applied sampling, but sample size was not in related to the efficiency of internal control of the entity. In 1955, American Institute of Accountants has published a study case of extending the audit sampling, summarizing audit program developed by certified public accountants, to show why sampling is necessary to extend the audit. The study was important because is one of the leading journal on sampling which recognize a relationship of dependency between detail and reliability testing of internal control.In 1964, the AICPA’s Auditing Standards Board has issued a report entitled “The relationship between statistical sampling and Generally Accepted Auditing Standards (GAAS)” which illustrated the relationship between the accuracy and reliability in sampling and provisions of GAAS.In 1978, the AICPA published the work of Donald M. Roberts,“Statistical Auditing”which explains the underlying theory of statistical sampling in auditing.In 1981, AICPA issued the professional standard, named “Audit Sampling”, which provides guidelines for both sampling methods, statistical and non-statistical.An auditor does not rely solely on the results of a single procedure to reach a conclusion on an account balance, class of transactions or operational effectiveness of the controls. Rather, the audit findings are based on combined evidence from several sources, as a consequence of a number of different audit procedures. When an auditor selects a sample of a population, his objective is to obtain a representative sample, ie sample whose characteristics are identical with the population’s characteristics. This means that selected items are identical with those remaining outside the sample.In practice, auditors do not know for sure if a sample is representative, even after completion the test, but they “may increase the probability that a sample is representative by accuracy of activities made related to design, sample selection and evaluation” [1]. Lack of specificity of the sample results may be given by observation errors and sampling errors. Risks to produce these errors can be controlled.Observation error (risk of observation) appears when the audit test did not identify existing deviations in the sample or using an inadequate audit technique or by negligence of the auditor.Sampling error (sampling risk) is an inherent characteristic of the survey, which results from the fact that they tested only a fraction of the total population. Sampling error occurs due to the fact that it is possible for Revista Română de Statistică nr. 5 / 2010Statistics and Auditthe auditor to reach a conclusion, based on a sample that is different from the conclusion which would be reached if the entire population would have been subject to audit procedures identical. Sampling risk can be reduced by adjusting the sample size, depending on the size and population characteristics and using an appropriate method of selection. Increasing sample size will reduce the risk of sampling; a sample of the all population will present a null risk of sampling.Audit Sampling is a method of testing for gather sufficient and appropriate audit evidence, for the purposes of audit. The auditor may decide to apply audit sampling on an account balance or class of transactions. Sampling audit includes audit procedures to less than 100% of the items within an account balance or class of transactions, so all the sample able to be selected. Auditor is required to determine appropriate ways of selecting items for testing. Audit sampling can be used as a statistical approach and a non- statistical.Statistical sampling is a method by which the sample is made so that each unit consists of the total population has an equal probability of being included in the sample, method of sample selection is random, allowed to assess the results based on probability theory and risk quantification of sampling. Choosing the appropriate population make that auditor’ findings can be extended to the entire population.Non-statistical sampling is a method of sampling, when the auditor uses professional judgment to select elements of a sample. Since the purpose of sampling is to draw conclusions about the entire population, the auditor should select a representative sample by choosing sample units which have characteristics typical of that population. Results will not extrapolate the entire population as the sample selected is representative.Audit tests can be applied on the all elements of the population, where is a small population or on an unrepresentative sample, where the auditor knows the particularities of the population to be tested and is able to identify a small number of items of interest to audit. If the sample has not similar characteristics for the elements of the entire population, the errors found in the tested sample can not extrapolate.Decision of statistical or non-statistical approach depends on the auditor’s professional judgment which seeking sufficient appropriate audits evidence on which to completion its findings about the audit opinion.As a statistical sampling method refer to the random selection that any possible combination of elements of the community is equally likely to enter the sample. Simple random sampling is used when stratification was not to audit. Using random selection involves using random numbers generated byRomanian Statistical Review nr. 5 / 2010Statistics and Audit a computer. After selecting a random starting point, the auditor found the first random number that falls within the test document numbers. Only when the approach has the characteristics of statistical sampling, statistical assessments of risk are valid sampling.In another variant of the sampling probability, namely the systematic selection (also called random mechanical) elements naturally succeed in office space or time; the auditor has a preliminary listing of the population and made the decision on sample size. “The auditor calculated a counting step, and selects the sample element method based on step size. Step counting is determined by dividing the volume of the community to sample the number of units desired. Advantages of systematic screening are its usability. In most cases, a systematic sample can be extracted quickly and method automatically arranges numbers in successive series.”[2].Selection by probability proportional to size - is a method which emphasizes those population units’recorded higher values. The sample is constituted so that the probability of selecting any given element of the population is equal to the recorded value of the item;Stratifi ed selection - is a method of emphasis of units with higher values and is registered in the stratification of the population in subpopulations. Stratification provides a complete picture of the auditor, when population (data table to be analyzed) is not homogeneous. In this case, the auditor stratifies a population by dividing them into distinct subpopulations, which have common characteristics, pre-defined. “The objective of stratification is to reduce the variability of elements in each layer and therefore allow a reduction in sample size without a proportionate increase in the risk of sampling.” [3] If population stratification is done properly, the amount of sample size to come layers will be less than the sample size that would be obtained at the same level of risk given sample with a sample extracted from the entire population. Audit results applied to a layer can be designed only on items that are part of that layer.I appreciated as useful some views on non-statistical sampling methods, which implies that guided the selection of the sample selecting each element according to certain criteria determined by the auditor. The method is subjective; because the auditor selects intentionally items containing set features him.The selection of the series is done by selecting multiple elements series (successive). Using sampling the series is recommended only if a reasonable number of sets used. Using just a few series there is a risk that the sample is not representative. This type of sampling can be used in addition to other samples, where there is a high probability of occurrence of errors. At the arbitrary selection, no items are selected preferably from the auditor, Revista Română de Statistică nr. 5 / 2010Statistics and Auditthat regardless of size or source or characteristics. Is not the recommended method, because is not objective.That sampling is based on the auditor’s professional judgment, which may decide which items can be part or not sampled. Because is not a statistical method, it can not calculate the standard error. Although the sample structure can be constructed to reproduce the population, there is no guarantee that the sample is representative. If omitted a feature that would be relevant in a particular situation, the sample is not representative.Sampling applies when the auditor plans to make conclusions about population, based on a selection. The auditor considers the audit program and determines audit procedures which may apply random research. Sampling is used by auditors an internal control systems testing, and substantive testing of operations. The general objectives of tests of control system and operations substantive tests are to verify the application of pre-defined control procedures, and to determine whether operations contain material errors.Control tests are intended to provide evidence of operational efficiency and controls design or operation of a control system to prevent or detect material misstatements in financial statements. Control tests are necessary if the auditor plans to assess control risk for assertions of management.Controls are generally expected to be similarly applied to all transactions covered by the records, regardless of transaction value. Therefore, if the auditor uses sampling, it is not advisable to select only high value transactions. Samples must be chosen so as to be representative population sample.An auditor must be aware that an entity may change a special control during the course of the audit. If the control is replaced by another, which is designed to achieve the same specific objective, the auditor must decide whether to design a sample of all transactions made during or just a sample of transactions controlled again. Appropriate decision depends on the overall objective of the audit test.Verification of internal control system of an entity is intended to provide guidance on the identification of relevant controls and design evaluation tests of controls.Other tests:In testing internal control system and testing operations, audit sample is used to estimate the proportion of elements of a population containing a characteristic or attribute analysis. This proportion is called the frequency of occurrence or percentage of deviation and is equal to the ratio of elements containing attribute specific and total number of population elements. WeightRomanian Statistical Review nr. 5 / 2010Statistics and Audit deviations in a sample are determined to calculate an estimate of the proportion of the total population deviations.Risk associated with sampling - refers to a sample selection which can not be representative of the population tested. In other words, the sample itself may contain material errors or deviations from the line. However, issuing a conclusion based on a sample may be different from the conclusion which would be reached if the entire population would be subject to audit.Types of risk associated with sampling:Controls are more effective than they actually are or that there are not significant errors when they exist - which means an inappropriate audit opinion. Controls are less effective than they actually are that there are significant errors when in fact they are not - this calls for additional activities to establish that initial conclusions were incorrect.Attributes testing - the auditor should be defining the characteristics to test and conditions for misconduct. Attributes testing will make when required objective statistical projections on various characteristics of the population. The auditor may decide to select items from a population based on its knowledge about the entity and its environment control based on risk analysis and the specific characteristics of the population to be tested.Population is the mass of data on which the auditor wishes to generalize the findings obtained on a sample. Population will be defined compliance audit objectives and will be complete and consistent, because results of the sample can be designed only for the population from which the sample was selected.Sampling unit - a unit of sampling may be, for example, an invoice, an entry or a line item. Each sample unit is an element of the population. The auditor will define the sampling unit based on its compliance with the objectives of audit tests.Sample size - to determine the sample size should be considered whether sampling risk is reduced to an acceptable minimum level. Sample size is affected by the risk associated with sampling that the auditor is willing to accept it. The risk that the auditor is willing to accept lower, the sample will be higher.Error - for detailed testing, the auditor should project monetary errors found in the sample population and should take into account the projected error on the specific objective of the audit and other audit areas. The auditor projects the total error on the population to get a broad perspective on the size of the error and comparing it with tolerable error.For detailed testing, tolerable error is tolerable and misrepresentations Revista Română de Statistică nr. 5 / 2010Statistics and Auditwill be a value less than or equal to materiality used by the auditor for the individual classes of transactions or balances audited. If a class of transactions or account balances has been divided into layers error is designed separately for each layer. Design errors and inconsistent errors for each stratum are then combined when considering the possible effect on the total classes of transactions and account balances.Evaluation of sample results - the auditor should evaluate the sample results to determine whether assessing relevant characteristics of the population is confirmed or needs to be revised.When testing controls, an unexpectedly high rate of sample error may lead to an increase in the risk assessment of significant misrepresentation unless it obtained additional audit evidence to support the initial assessment. For control tests, an error is a deviation from the performance of control procedures prescribed. The auditor should obtain evidence about the nature and extent of any significant changes in internal control system, including the staff establishment.If significant changes occur, the auditor should review the understanding of internal control environment and consider testing the controls changed. Alternatively, the auditor may consider performing substantive analytical procedures or tests of details covering the audit period.In some cases, the auditor might not need to wait until the end audit to form a conclusion about the effectiveness of operational control, to support the control risk assessment. In this case, the auditor might decide to modify the planned substantive tests accordingly.If testing details, an unexpectedly large amount of error in a sample may cause the auditor to believe that a class of transactions or account balances is given significantly wrong in the absence of additional audit evidence to show that there are not material misrepresentations.When the best estimate of error is very close to the tolerable error, the auditor recognizes the risk that another sample have different best estimate that could exceed the tolerable error.ConclusionsFollowing analysis of sampling methods conclude that all methods have advantages and disadvantages. But the auditor is important in choosing the sampling method is based on professional judgment and take into account the cost / benefit ratio. Thus, if a sampling method proves to be costly auditor should seek the most efficient method in view of the main and specific objectives of the audit.Romanian Statistical Review nr. 5 / 2010Statistics and Audit The auditor should evaluate the sample results to determine whether the preliminary assessment of relevant characteristics of the population must be confirmed or revised. If the evaluation sample results indicate that the relevant characteristics of the population needs assessment review, the auditor may: require management to investigate identified errors and likelihood of future errors and make necessary adjustments to change the nature, timing and extent of further procedures to take into account the effect on the audit report.Selective bibliography:[1] Law no. 672/2002 updated, on public internal audit[2] Arens, A şi Loebbecke J - Controve …Audit– An integrate approach”, 8th edition, Arc Publishing House[3] ISA 530 - Financial Audit 2008 - International Standards on Auditing, IRECSON Publishing House, 2009- Dictionary of macroeconomics, Ed C.H. Beck, Bucharest, 2008Revista Română de Statistică nr. 5 / 2010Statistics and Audit摘要美国公司的规模迅速增加,从第二十世纪初创造了必要的审计程序,根据选定的部分总人口的审计,以获得可靠的审计证据,以描述整个人口组成的帐户余额或类别的交易。

儿童教育外文翻译文献

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. 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. 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. 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)。

基于铝基碳化硅颗粒金属基体复合材料表面完整性的实验研究N. Suresh Kumar Reddy, , Shin Kwang-Sup,杨敏阳韩国大田,韩国先进科学技术研究院,机械工程系2007年12月5日发表引言:在端铣铝基碳化硅颗粒的金属基体复合材料过程中,材料产生的局部表面质量(PMMCs)是很重要的,因为它能在很大程度上影响成品部件的性能。

因此,对表面完整性的估计可以满足性能评估的要求。

因此,理解表面完整性有许多优点,例如,可以降低失败率、提高组件的完整性并且降低总体成本。

本文提供了一个对端铣铝基碳化硅复合材料实验的研究结果。

这个实验研究的目的是为了提高使用TiAlN涂层的硬质合金刀具来端铣铝基碳化硅复合材料机械加工性能的了解。

研究在不同铣削条件下加工铝基碳化硅复合材料和铝合金材料的表面质量和次表面损伤情况。

对铝基碳化硅复合材料和铝合金材料的比较,是从表面完整性的(表面粗糙度、残余应力、微观组织结构和显微硬度)展开的,这是为了了解这两种材料的机械切削性能。

实验结果表明根据表面粗糙度和对铣削刀具较低的铣削阻力的标准,相比于非增强相的铝合金材料,铝基碳化硅增强复合材料可以提高机械加工性能。

本实验结果有助于更好的理解端铣的加工工艺过程,可以提供确保更好的加工铝基碳化硅材料的输入参数和预期的领先技术,并且通过在各种工业应用中使用铝基碳化硅复合材料取代铝合金材料来提高经济效益。

关键词:铝基碳化硅颗粒金属基体复合材料;表面完整性;端铣。

1介绍金属基体复合材料(MMC)代表了新一代的具有很大可适应性和新颖特性潜能的材料。

因此,金属集体复合材料在科学、技术和商业方面很重要。

由于越来越多的性能要求,在许多应用中,越来越多的金属基体复合材料被用来取代传统的材料,特别是在汽车和娱乐行业(林等人,2001)。

在各种类型的金属基体复合材料中,铝合金基体复合材料的应用越来越广泛。

以碳化硅为增强相的铝合金复合材料是应用最广泛的复合材料,铝基碳化硅复合材料可以通过一系列工艺来生产,其中包括熔融加工和粉末冶金。

这些低成本的复合材料在应用中具有良好的性能,除了具有高的比强度、刚度和抗疲劳性,耐高温的性能是必须要具备的,这是复合材料典型的特点。

所以,这些材料在各种工程应用中被用作替换材料,如汽缸衬垫、汽车传动轴、汽车活塞、自行车车架等(恩利和斯克拉德,1998)。

当加工MMC时最需要注意的是加工区中的高热区。

当受到大量热量时,工件的受热膨胀会导致尺寸不精确。

同时该工具也会受到较大的热载荷,这会导致更大范围的扩散、氧化等,最终导致刀具磨损严重。

为了追求MMC的加工性能,必须弥补加工过程中的缺点。

新的涂层工具具有巨大的潜力来提升这一类材料的机械可加工性。

在这个方向,氮化钛涂层铝基(TiAlN)硬质合金刀具是一个潜在的替代品。

进一步的分析表明,在PMMC表面和次表面的铣削变形的问题还没有得到解决(林等人,1998,恩利和斯克拉德,1998)。

此外,已经做了不严格的调查来找出铣削参数在加工金属基体复合材料过程中对次表面变形的影响。

这是非常重要的,因为这些因素对加工组件的性能起着重要作用。

因此,鉴于这些复合材料不断增长的工程应用需求,需要详细和系统的研究复合材料的加工特性,这些对于在实际工程应用中的快速应用是非常必要的。

这种研究将会有助于提高这些材料所要求的公差特性的有效性和经济性。

从金属切削的理论可以知道,表面完整性的研究是了解材料加工特性最有效的途径。

因此,铝基碳化硅复合材料加工特性的测量代表了加工过程分析最重要的方面之一,这种材料在未来将会得到大量应用。

因此,本次研究的目的是为了研究具有氮化钛涂层刀具端铣铝基碳化硅复合材料的可加工性。

是为了研究在不同铣削条件,铣削铝基碳化硅复合材料和铝基复合材料产生的表面质量和次表面损伤的程度。

在表面完整性(粗糙度、残余应力和硬度)的基础上,对铝基碳化硅复合材料和铝基复合复合材料的比较,是为了了解这两种材料的可加工性。

2试验方法实验研究是通过使用铝基碳化硅复合材料展开的。

在这项研究中使用的碳化硅颗粒的化学分析结果如表一所示。

使用体积分数为20%的碳化硅颗粒来制造复合材料。

通过使用激光粒度仪的“马尔文激光粒度分析模型”来测定颗粒的粒径。

被加工的材料是颗粒大小为32微米的体积分数为20%的铝基碳化硅颗粒复合材料。

研究中使用的2024铝合金复合材料的相关化学分析如表2所示。

2.1铣削条件铣削是一个非常复杂的切削过程,涉及切削速度、进给速度、切削深度、刀具几何形状等参数。

通过一系列实验对影响表面光洁度最大的因素进行了研究。

实验的影响因素是切削速度、进给速度和切削深度。

实验的情况如图3所示。

实验是在干燥条件下进行的。

采用高精度的数控铣刀和立式铣头来进行实验。

切削刀具是TiAlN固体涂层的直径为20毫米的硬质合金四齿端铣刀。

实验中使用了三种不同的刀具。

每个刀具都被用于8个实验,在每次实验后,都会使用光学显微镜来测量已使用的铣刀,来确定后刀面或表面的磨损程度。

在这些实验中,刀具的寿命标准是0.3毫米。

实验中分别使用了赋值和截止长度为0.8到5毫米的表面粗糙度测试仪对表面粗糙度进行了检测。

表面粗糙度是取自加工表面四个位置(分别成90°),在加工表面每处重复取值两次的平均值。

通过光学显微镜对垂直于工件表面的显微硬度进行分析,实验中使用了负载为25克的维氏显微硬度计。

在本实验中没能换个,由于没有成文的X射线衍射(XRD)残余应力的测量标准,对使用了sin2ψ 技术X射线处理的表面进行残余应力的测量。

选择铁α{ 2 1 1 }反射和CrK α辐射进行测试,其中技术参数渗透率为5微米、峰值范围是2θ为140–170°。

3结果与讨论表面完整性是影响工件加工质量的重要因素之一,因为表面完整性会影响工件的功能特性,例如相容性、抗疲劳性和表面摩擦。

这也是评估材料可加工性的标准之一。

因此,表面完整性也可以成为一个重要的性能测试指标。

因此,对于为了评估端铣的效果,来测试表面完整性,这是很必要的。

在这个背景下,可以通过进行实验,来测量切削速度、进给量和背吃刀量的影响。

在实验之前和之后刀具磨损的测量结果,表明具有TiAlN涂层的刀具可以承受在所选择的加工状态下产生的热量。

具有TiAlN涂层的铣刀可以提高加工性能,这是由于在很高的工作温度下,涂层可以保持较高的硬度和抗氧化能力。

此外,在这项实验中,所有的注意事项表明,在刀具顶端中不会提示对工件材料的附着要求。

然而,它会造成从刀具顶端前角到前刀面的一个小间隙。

一个可能的解释,通过分析在刀具前刀面的正应力分布,可以测量刀具前刀面工件材料的附着力。

3.1表面粗糙度在这个实验中,选择的表面粗糙度对应的变化量如图1所示。

从图1中对可以看出,相比于加工其他所有类型的铝合金材料,加工铝基碳化硅复合材料得到的表面粗糙粗是很低的。

这是由于在高温下铝基碳化硅复合材料加工后增加工件材料的流动性导致的。

这可能会有助于芯片更容易的形成,从而在铝基碳化硅复合材料加工条件下,降低其表面粗糙度。

但是,不断上升的温度通常会导致工件材料侧流上升。

而不断上升的工件材料的侧流又会造成更高的表面粗糙度。

但是,这有两个因素将会导致表面粗糙度的上升或下降。

考虑到在高温下增加了塑性将会减少应力,一个因素将会导致粗糙度的下降;又由于在高温下增加了侧流,其它因素将会增加粗糙度。

在这个实验中,我们可以发现,当采用了较高的进给速度,将不会大幅度增加边缘流动性(凯撒和阿贝威,1999)。

所以,在这些条件下,相比于第二个因素,第一个因素的效果将会处于决定性地位。

因此,相比于加工铝合金材料,加工铝基碳化硅复合材料的粗糙度将会很低。

图1 Variation of surface roughness with cutting speed at different depth of cuts and feeds.从图一中可以观察,在研究中,在其它条件不变的情况下,随着进给速度的增加,铝基碳化硅复合材料的表面粗糙度也在增加。

这是因为最大芯片厚度在增加,由于进给速度的增加,将导致切削力和表面粗糙度的增加。

此外,还可以看出,随着切削速度的增加,表面粗糙度在降低。

这种趋势是可以被预料到的,因为随着切削速度的增加,机械加工变的更加绝热,并且在剪切区域产生的热量,在材料通过这个区域时不能在很短的时间内排出。

因此,温度升高软化材料辅助晶界位错和表面粗糙度的降低可以在图1中看出。

在加工条件下,对于铝基碳化硅复合材料而言,表面粗糙度最小值对应的最优值(相对于输入加工参数附录A.1所示)的计算方法是利用遗传算法计算(赛睿库马瑞得和威客若,2006),如表4所示。

通过这项工作中的遗传算法可以观察到,铝基碳化硅复合材料的表面粗糙度最小值,发现在0.96到1.53微米内变化。

在最佳的铣削条件下,在切削速度是188mm/min、进给量是0.10mm/rev和背吃刀量是0.24mm的条件下,表面粗糙度的最小值是0.96微米。

通过遗传算法的应用来获得最佳的铣削状态的方法,在计算机辅助处理中将会是很实用的。

通过一系列的加工方法产生较高的工件质量、具有较高的公差要求,并且在自动化机械的自适应控过程中,优化加工铝基碳化硅复合材料铣削条件,需要较高的表面质量、较好的尺寸精度。

实验研究带来的益处,将使得机械制造工艺更具竞争力和经济性。

3.2显微硬度对横截面样品进行了显微硬度测量。

图2表示在显微硬度的变化中,截面以下深度的函数。

从显微硬度测量的结果可以知道,铝基碳化硅复合材料和铝合金材料没有明显的改善次表面的性能。

在加工表面下,随着铣削深度的增加,显微硬度也在不断增加。

这可能是由于如下原因,在加工过程中,随着切削过程的温度变化,造成退火工件已加工表面的软化。

图2 Microhardness depth variations of machined surfaces at different levels of cut conditions从图2中可以看出,加工影响层的深度受到铣削参数的影响。

随着切削速度、进给量和背吃刀量的增加,加工影响层的深度也在增加。

此外,随着任何切削参数的增加,材料的硬化程度也在增加。

这可能是因为如下,切削温度的增加可能是加工中次表面硬化的一个原因;因为切削温度将会导致基体材料的热变形。

这是值得注意的,在加工表面和20微米深处的测量硬度有分散情况。

这是因为在碳化硅颗粒周围颗粒拔出、颗粒断裂和裂纹生长处于优先地位。

3.3残余应力正如文献中所指出的,在加工中由于生高温,可能造成微观结构变化。

在地面上加工的条件下,根据材料的不同,这可能会导致产生拉伸或者压缩应力。

根据研究可知(马尔,1989),残余应力可以由3个因素引起:热膨胀的影响、工件显微组织结构变化的影响和机械性能影响。

相关文档
最新文档