朱庆涛 外文翻译
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学术交流英语教程第二版第2版王文宇翻译答案P38 汉译英(1)我们在你们的主页中了解到你们是专门研究是专门研究X的,这正是我们目前研究的领域。
如果有可能我们愿意与你们交换研究资料并邀请你们到我实验室进行学术访问。
我方将设法为你们的来访和我们之间未来的合作所需的手续提供便利。
We have learned from your homepage that you are specialized in X, what we are doing now. If possible, we are willing to exchange research materials with you and invite you to our laboratory for academic visit. We will try to facilitate your visit and the necessary procedures for future cooperation between us.(2)来自南京的问候!我和您曾在上周伦敦“X国际研讨会”上见过面,当时我们就双方实验室研究工作做了交流,并简单讨论了未来合作的可能性。
今致此邮件,进一步介绍一下我们的研究团队和我们目前的一些研究课题。
希望您也能给我们提供一个有兴趣与我方建立联系的人员名单。
Greetings from Xiangtan! We met last week at the International panel discussion of X Conference in London,we talked about the laboratory research work of both sides and briefly discussed the possibility of future cooperation. With this email I would like to further introduce our team and some projects we are doing. We sincerely hope you can also recommend a list of members that would like establish a contact with us.(3)我系将负责安排您在南京期间的活动并为您支付在南京的全部费用。
中国石油大学(华东)本科毕业设计(论文)外文翻译学生姓名:陈兆龙学号:04053307专业班级:电气工程及其自动化04-3班指导教师:刘丽萍李浩光2008年6月20日英文资料1.1 Control SystemOne of the most fundamental concepts in the area of advanced manufacturing technologies is numerical control (NC).Prior to the advent of NC, all machine tools were manual operated and controlled. Among the many limitations associated with manual control machine tools, perhaps none is more prominent than the limitation of operator skills. With manual control, the quality of the product is directly related to and limited to the skills of the operator . Numerical control represents the first major step away from human control of machine tools.Numerical control means the control of machine tools and other manufacturing systems though the use of prerecorded, written symbolic instructions. Rather than operating a machine tool, an NC technician writes a program that issues operational instructions to the machine tool, For a machine tool to be numerically controlled , it must be interfaced with a device for accepting and decoding the p2ogrammed instructions, known as a reader.1.2 Numerical ControlNumerical control was developed to overcome the limitation of human operator , and it has done so . Numerical control machines are more accurate than manually operated machines , they can produce parts more uniformly , they are faster, and the long-run tooling costs are lower . The development of NC led to the development of several other innovations in manufacturing technology:1.Electrical discharge machining.ser cutting.3.Electron beam welding.Numerical control has also made machine tools more versatile than their manually operated predecessors. An NC machine tool can automatically produce a wide variety of par4s , each involving an assortment of undertake the production of products that would not have been feasible from an economic perspective using manually controlled machine tools and processes.Like so many advanced technologies , NC was born in the laboratories of the Massachusetts Institute of Technology . The concept of NC was developed in the early 1950s with funding provided by the U.S Air Force .In its earliest stages , NC machines were able to make straight cuts efficiently and effectively.However ,curved paths were a problem because the machine tool had to be programmed to undertake a series of horizontal and vertical steps to produce a curve. The shorter is the straight lines making up the step ,the smoother is 4he curve . Each line segment in the steps had to be calculated.This problem led to the development in 1959 of the Automatically Programmed Tools (APT) language for NC that uses statements similar to English language to define the part geometry, describe the cutting tool configuration, and specify the necessary motions. The development of the APT language was a major step forward in the further development of NC technology. The original NC system were vastly different from those used punched paper , which was later to replaced by magnetic plastic tape .A tape reader was used to interpret the instructions written on the tape for the machine .Together, all /f this represented giant step forward in the control of machine tools . However ,there were a number of problems with NC at this point in its development.A major problem was the fragility of the punched paper tape medium . Itwas common for the paper containing the programmed instructions to break or tear during a machining process, This problem was exacerbated by the fact that each successive time a part was produced on a machine tool, the paper tape carrying the programmed instructions had to rerun thought the reader . If it was necessary to produce 100 copies of a given part , it was also necessary to run the paper tape thought the reader 100 separate times . Fragile paper tapes simply could not withstand the rigors of shop floor environment and this kind of repeated use.This led to the development of a special magnetic tape . Whereas the paper tape carried the programmed instructions as a series of holes punched in the tape , theThis most important of these was that it was difficult or impossible to change the instructions entered on the tape . To make even the most minor adjustments in a program of instructions, it was necessary to interrupt machining operations and make a new tape. It was also still necessary to run the tape thought the reader as many times as there were parts to be produced . Fortunately, computer technology become a reality and soon solved the problems of NC, associated with punched paper and plastic tape.The development of a concept known as numerical control (DNC) solve the paper and plastic tape problems associated with numerical control by simply eliminating tape as the medium for carrying the programmed instructions . In direct numerical control, machine tools are tied, via a data transmission link, to a host computer and fed to the machine tool as needed via the data transmission linkage. Direct numerical control represented a major step forward over punched tape and plastic tape. However ,it is subject to the same limitation as all technologies that depend on a host computer. When the host computer goesdown , the machine tools also experience down time . This problem led to the development of computer numerical control.The development of the microprocessor allowed for the development of programmable logic controllers (PLC) and microcomputers . These two technologies allowed for the development of computer numerical control (CNC).With CNC , each machine tool has a PLC or a microcomputer that serves the same purpose. This allows programs to be input and stored at each individual machine tool. CNC solved the problems associated downtime of the host computer , but it introduced another problem known as data management . The same program might be loaded on ten different microcomputers with no communication among them. This problem is in the process of being solved by local area networks that connect.1.3 Digital Signal ProcessorsThere are numerous situations where analog signals to be processed in many ways, like filtering and spectral analysis , Designing analog hardware to perform these functions is possible but has become less and practical, due to increased performance requirements, flexibility needs , and the need to cut down on development/testing time .It is in other words difficult pm design analog hardware analysis of signals.The act of sampling an signal into the hat are specialised for embedded signal processing operations , and such a processor is called a DSP, which stands for Digital Signal Processor . Today there are hundreds of DSP families from as many manufacturers, each one designed for a particular price/performance/usage group. Many of the largest manufacturers, like Texas Instruments and Motorola, offer both specialised DSP‟s for certain fields like motor-control ormodems ,and general high-performance DSP‟s that can perform broad ranges of processing tasks. Development kits an` software are also available , and there are companies making software develop ment tools for DSP‟s that allows the programmer to implement complex processing algorithms using simple “drag …n‟drop” methodologies.DSP‟s more or less fall into two categories depending on the underlying architecture-fixed-point and floating-point. The fixed-point devices generally operate on 16-bit words, while the floating-point devices operate on 32-40 bits floating-point words. Needless to say , the fixed-point devices are generally cheaper . Another important architectural difference is that fixed-point processors tend to have an accumulator architecture, with only one “general purpose”register , making them quite tricky to program and more importantly ,making C-compilers inherently inefficient. Floating-point DSP‟s behave more like common general-purpose CPU‟s ,with register-files.There are thousands of different DSP‟s on the market, and it is difficult task finding the most suitable DSP for a project. The best way is probably to set up a constraint and wishlist, and try to compare the processors from the biggest manufacturers against it.The “big four” manufacturers of DSPs: Texas Instruments, Motorola, AT&T and Analog Devices.Digital-to-analog conversionIn the case of MPEG-Audio decoding , digital compressed data is fed into the DSP which performs the decoding , then the decoded samples have to be converted back into the analog domain , and the resulting signal fed an amplifier or similar audio equipment . This digital to analog conversion (DCA) isperformed by a circuit with the same name & Different DCA‟s provide different performance and quality , as measured by THD (Total harmonic distortion ), number of bits, linearity , speed, filter characteristics and other things.The TMS320 family DSP of Texas InstrumentsThe TLS320family consists of fixed-point, floating-point, multiprocessor digital signal processors (DSP) , and foxed-point DSP controllers. TMS320 DSP have an architecture designed specifically for real-time signal processing . The‟F/C240 is a number of the‟C2000DSP platform , and is optimized for control applications. The‟C24x series of DSP controllers combines this real-time processing capability with controller peripherals to create an ideal solution for control system applications. The following characteristics make the TMS320 family the right choice for a wide range of processing applications: --- Very flexible instruction set--- Inherent operational flexibility---High-speed performance---Innovative parallel architecture---Cost effectivenessDevices within a generation of the TMS320 family have the same CPU structure but different on-chip memory and peripheral configurations. Spin-off devices use new combinations of On-chip memory and peripherals to satisfy a wide range of needs in the worldwide electronics market. By integrating memory and peripherals onto a single chip , TMS320 devices reduce system costs and save circuit board space.The 16-bit ,fixed-point DSP core of the …C24x devices provides analog designers a digital solution that does not sacrifice the precision and performanceof their system performance can be enhanced through the use of advanced control algorithms for techniques such as adaptive control , Kalman filtering , and state control. The …C24x DSP controller offer reliability and programmability . Analog control systems, on the other hand ,are hardwired solutions and can experience performance degradation due to aging , component tolerance, and drift.The high-speed central processing unit (CPU) allows the digital designer to process algorithms in real time rather than approximate results with look-up tables. The instruction set of these DSP controllers, which incorporates both signal processing instructions and general-purpose control functions, coupled with the extensive development time and provides the same ease of use as traditional 8-and 16-bit microcontrollers. The instruction set also allows you to retain your software investment when moving from other general-purpose…C2xx generation ,source code compatible with the‟C2x generation , and upwardly source code compatible with the …C5x generation of DSPs from Texas Instruments.The …C24x architecture is also well-suited for processing control signals. It uses a 16-bit word length along with 32-bit registers for storing intermediate results, and has two hardware shifters available to scale numbers independently of the CPU . This combination minimizes quantization and truncation errors, and increases p2ocessing power for additional functions. Such functions might include a notch filter that could cancel mechanical resonances in a system or an estimation technique that could eliminate state sensors in a system.The …C24xDSP controllers take advantage of an set of peripheral functions that allow Texas Instruments to quickly configure various series members for different price/ performance points or for application optimization.This library of both digital and mixed-signal peripherals includes:---Timers---Serial communications ports (SCI,SPI)---Analog-to-digital converters(ADC)---Event manager---System protection, such as low-voltage and watchdog timerThe DSP controller peripheral library is continually growing and changing to suit the of tomorrow‟s embedded control marketplace.The TMS320F/C240 is the first standard device introduced in the (24x)series of DSP controllers. It sets the standard for a single-chip digital motor controller. The …240 can execute 20 MIPS. Almost all instructions are executed in a simple cycle of 50 ns . This high performance allows real-time execution of very comple8 control algorithms, such as adaptive control and Kalman filters. Very high sampling rates can also be used to minimize loop delays.The …240 has the architectural features necessary for high-speed signal processing and digital control functions, and it has the peripherals needed to provide a single-chip solution for motor control applications. The …240 is manufactured using submicron CMOS technology, achieving a log power dissipation rating . Also included are several power-down modes for further power savings. Some applications that benefit from the advanced processing power of the …240 include:---Industrial motor drives---Power inverters and controllers---Automotive systems, such as electronic power steering , antilock brakes, and climate control---Appliance and HV AC blower/ compressor motor controls---Printers, copiers, and other office products---Tape drives, magnetic optical drives, and other mass storage products---Robotic and CNC milling machinesTo function as a system manager, a DSP must have robust on-chip I/O and other peripherals. The event manager of the …240 is unlike any other available on a DSP . This application-optimized peripheral unit , coupled with the high performance DSP core, enables the use of advanced control techniques for high-precision and high-efficiency full variable-speed control of all motor types. Include in the event manager are special pulse-width modulation (PWM) generation functions, such as a programmable dead-band function and a space vector PWM state machine for 3-phase motors that provides state-of-the-art maximum efficiency in the switching of power transistors.There independent up down timers, each with it‟s own compare register, support the generation of asymmetric (noncentered) as well as symmetric (centered) PWM waveforms.1.4 Open-Loop and Closed-Loop ControlOpen-loop Control SystemsThe word automatic implies that there is a certain amount of sophistication in the control system. By automatic, it generally means That the system is usually capable of adapting to a variety of operating conditions and is able to respond to a class of inputs satisfactorily . However , not any type of control system has the automatic feature. Usually , the automatic feature is achieved by feed.The feedback structure, it is called an open-loop system , which is the simplest and most economical type of control system.inaccuracy lies in the factthat one may not know the exact characteristics of the further ,which has a definite bearing on the indoor temperature. This alco points to an important disadvantage of the performance of an open -loop control system, in that the system is not capable of adapting to variations in environmental conitions or to external disturbances. In the case of the furnace control, perhaps an experienced person can provide control for a certain desired temperature in the house; but id the doors or windows are opened or closed intermittently during the operating period, the final temperature inside the house will not be accurately regulated by the open-loop control.An electric washing machine is another typical example of an open-loop system , because the amount of wash time is entirely determined by the judgment and estimation of the human operator . A true automatic electric washing machine should have the means of checking the cleanliness of the clothes continuously and turn itsedt off when the desired degised of cleanliness is reached.Closed-Loop Control SystemsWhat is missing in the open-loop control system for more accurate and more adaptable control is a link or feedback from the output to the input of the system . In order to obtain more accurate bontrol, the controlled signal c(t) must be fed back and compared with the reference input , and an actuating signal proportional to the difference of the output and the input must be sent through the system to correct the error. A system with one or more feedback pat(s like that just described is called a closed-loop system. human being are probably the most complex and sophisticated feedback control system in existence. A human being may be considered to be a control system with many inputs and outputs, capableof carrying out highly complex operations.To illustrate the human being as a feedback control system , let us consider that the obj ective is to reach for an object on a perform the task. The eyes serve as a sensing device which feeds back continuously the position of the hand . The distance between the hand and the object is the error , which is eventually brought to zero as the hand reacher the object. This is a typical example of closed-loop control. However , if one is told to reach for the object and then is blindolded, one can only reach toward the object by estimating its exact position. It isAs anther illustrative example of a closed-loop control system, shows the block diagram of the rudder control system of the basic alements and the bloca diagram of a closed-loop control system are shown in fig. In general , the configuration of a feedback control system may not be constrained to that of fig & . In complex systems there m ay be multitude of feedback loops and element blocks.中文翻译1.1控制系统数字控制机床常常重达上百吨,但却常常要求切削工具的定位精度达到0.002毫米。
英语专业论文开题报告中译英的翻译策略A Study on C-E Translation of the Chinese Medicine Instructions--From the Perspective of Functional Equivalence Theory 2xxxxxxxx xx x班1. Rationale and Significance of the Proposed StudyNowadays, the international exchanges and cooperations among various industries increase frequently because of the economic globalization. With the vigorous development of China ’s economy, especially after China's entry into the world trade organization, drug import and export industry faces unprecedented opportunities and challenges, and China has gradually bee the global drug exporter. In addition to medicine production quality, instruction also plays an important role in the medicine exports, so whose quality of chinese-english translation directly related to whether export medicines can be aepted by the international market. Faithful, aurate, smooth chinese-english medicine instruction can not only protect the patient's medication safety, but can increase the satisfaction and reliability of foreign medical workers and patients to China’s export medicines, and upgrade the international reputation of China’s medicine industry.2. Literature ReviewAlthough traditional chinese medicine has long been spread abroad, a lot of translation of traditional Chinese medicine instruction of China still adopt the way of Chinese pinyin, which can neither introduce Chinese traditional medicine, nor attract foreign buyers.Currently, those translators who engaged in the translation of traditional chinese medicine are either TCM medical workers whose english skill is not solid, or english translators who only know little or even nothing about traditional chinese medicine and culture. The translation of the former will usually has one kind or another error in language, even chinglish, which confuse the foreigners; while the latter will use reference books, but they interpret without real understanding, which make the chinese medicine instructions beyond recognition. In general, the quality of the chinese medicine instructions translation is not high.3. Research Questions/Problems to be Investigated(1) What are the features of chinese medicine instructions in parison with those of english ?(2) What principle and standard should the translation of chinese medicine instructions ply with ?4. Methodology and Data CollectionThis research is planned to find out the principles for the translation of chinese medicine instructions. With thispurpose, 3 chinese medicine instructions and their corresponding english versions are collected from pharmacies, hospitals and the inter.Aording to the research questions, the research can be divided into two steps. Each step answers each research question. The first one is to find out the problems in the translation of medicine instructions through paring the chinese medicine instructions and the translated english one.Then, to solve these problems and improve the quality of the translation, the author applies the theory of Nida’s functional equiv alence. With this theory as direction, the author tries to sum up some detailed translation strategies to guild the translation in their translation practices.5. Theoretical FrameworkNida’s Functional Equivalence6. Outline/Organization of the Proposed StudyOutline:1. Introduction1.1 The Chinese Medicine Instructions1.1.1 Definition of the Chinese Medicine Instructions1.1.2 Functions of the Chinese Medicine Instructions1.1.3 Structure of the Chinese Medicine Instructions1.1.4 Language features of the Chinese Medicine Instructions1.2 Significance and Rationale1.3 Research Questions1.4 Organization of the Thesis2. Literature Review2.1 Studies on Functional Equivalence2.2 Studies on the Translation of Chinese Medicine Instructions2.3 Chinese Medicine Instructions translations based on Functional Equivalence Theory2.4 Advancement and Weakness of the Existing Studies3. Theoretical Framework3.1 The Definition of Functional Equivalence Theory3.2 The Core Concepts of Functional Equivalence Theory4. Existing Problems in the Translation of Chinese Medicine Instructions5. Relevant Principles and Strategies Applied in the Translation of Chinese Medicine Instructions6. Case Analysis7. Conclusion7.1 Findings of the Research7.2 Limitations and Suggestions for Future Studies7. Tentative Conclusion and Potential DifficultiesTentative Conclusion:With the advance of globalization, the exchanges of medical are more and more frequent, which help to quicken the pace of development of medicine. Chinese medicine instructions are an important channel for spreading the traditional popularity. And well-translated chinese medicine instructions turn out to be very important for improving the popularity of traditional chinese medicine. This study aims to facilitate the translation of chinese medicine instructions from the perspective of functional equivalence. Though analyzing 3 english and chinese medicine instructions, the author found the problems in the translation of instructions: lack of faithful, lack of readability, lack of unified standard, and chinese thought patterns; and some strategies based on this.Potential Difficulties:Have no idea about the research status of chinese medicine instructions translation;Not familiar with functional equivalence theory;Inplete examples analysis of Chinese medicine instruction translation8. ReferenceNida Eugene A. Language, Culture, andtranslation[M].Shanghai:Shanghai Foreign Language Education Press,1993.Nida Eugene A. Toward a Science of Translating[M]. Leiden: E.J.Brill,1964.Nida Eugene A. Language and Culture: Contexts in Translating[M]. Shanghai:Shanghai Foreign Language Education Press,xx.Nida Eugene A.&Charles R.Taber. The Theory and Practice of Translation[J], Leiden: E.J.Brill,1982.马会娟,《奈达翻译理论研究》[M],外语研究出版社,xx.谭载喜,《奈达论翻译》[M],中国对外翻译出版公司,1984.罗海燕,施蕴中,英译根本问题及策略[J],中华药学刊,xx年01期.林英, 基于语料库的汉英翻译常见错误分析及策略[D], 第四军医大学,xx年.曹情, 中文药品说明书的翻译[D], 南华大学,xx年.赵旭,李勇军, 中药产品说明书英译标准性的研究,《中国民族民间医药》,xx年17期.baike.baidu.模板,内容仅供参考。
跨文化背景视域下石油英语英汉翻译探究摘要:当前国内外石油勘探、石油开采等技术互通需要以翻译作为媒介,从而实现技术上的沟通和交流。
文章以跨文化为背景,以石油英语领域中词汇、句法和语篇特征分析为基础,从专业术语、被动语态、嵌入句和语篇衔接进行案例分析,探究石油英语英汉翻译的技巧,旨在总结石油英语英汉翻译的方法,为同领域的翻译实践提供借鉴。
关键词:石油英语;英汉翻译;专业术语;语篇衔接;跨文化中图分类号:H315.9文献标识码:A文章编号:2095-0438(2023)11-0081-02(东北石油大学黑龙江大庆163318)石油英语的专业特征较强,包含石油领域的专业术语和专有名词,行文过程中嵌入成分较多,结构相对复杂,为翻译工作带来了一定困难和挑战。
翻译是一种知识迁移、话语重构和价值创造活动。
[1]石油英语翻译的目的在于跨越文化之间的差异,突破英汉语言之间的障碍,使得双方在石油技术上得以沟通和交流。
一、石油英语英汉翻译的跨文化体现(一)专业术语和普通名词术语化。
首先,设计石油领域的术语和专有名词较多。
常见和熟知的术语可通过术语词典、网络资料查询,直译出其汉语意义,将源语信息准确地传递给目的语读者。
例如:derrick (井架)、anticline (背斜)、deposition (沉积)、sedimentary rock (沉积岩)、shale (页岩)、WOB (weight on bit 钻压)。
其次,石油英语中存在普通词汇赋予术语意义的现象。
在石油专业英语中普遍存在普通名词术语化的现象,导致普通词在丧失部分原有词义的同时,又保留其中一部分相关词义的内容,并与石油行业的专业概念相结合,从而演变成为石油专业术语。
[2]针对此类词汇的翻译,译者需要从源语文化出发,了解其在石油领域内的所指,并在目的语中找到对应的术语表达。
例如:reservoir 在普通领域的意义为“水库、蓄水池、储藏”等,而在石油英语中,意为“油藏”;completion 在普通领域的意义为“完成、结束”等,而在石油英语中,意为“完井”。
INTERNATIONAL JOURNAL OF PRECISION ENGINEERING AND MANUFACTURING Vol. 14, No. 6, pp. 925-936JUNE 2013 / 925© KSPE and Springer 2013Power Consumption and Tool Wear Assessment when Machining Titanium AlloysSalman Pervaiz 1,2, Ibrahim Deiab 1, and Basil Darras 1,#1 Department of Mechanical Engineering, College of Engineering, American University of Sharjah, Sharjah, United Arab Emirates, 266662 Department of Production Engineering, KTH Royal Institute of Technology, S-100 44 Stockholm, Sweden# Corresponding Author / E-mail: bdarras@, TEL: +971-6-515-2590, FAX: +971-6-515-2979KEYWORDS: Machinability, Wear mechanisms, Energy consumption, TitaniumTitanium alloys are of interest for aerospace industries due to their high strength to weight ratio, outstanding corrosion and erosion properties and ability to operate at higher temperature. They are classified as difficult to cut materials because of their low thermal conductivity, high chemical reactivity and high strength at elevated temperature. The machinability rating of titanium alloys is low compared to other materials from many aspects. This study focuses on studying the cutting tool wear and power consumption when machining Titanium alloys under different cutting conditions. Design of experiments was used to develop a test matrix that cover the range of cutting conditions recommended for machining titanium alloys. Cutting forces, power consumption, tool wear and surface roughness were measured and analyzed. Tool wear mechanisms were also studied using scanning electron microscopy.Manuscript received: November 12, 2012 / Accepted: April 3, 20131. IntroductionTitanium alloys are being used extensively for the manufacturing of air-crafts, aero-engines, biomedical equipment and chemical processing units. Titanium alloys exhibit very good strength at high temperature and low density. Titanium alloys offer good corrosion resistance making them suitable for marine industry.1 H owever, titanium alloys show poor machinability rating. Main causes of poor machinability are low thermal conductivity, high strength at elevated temperature, high chemical reactivity and low young’s modulus.2Concept of environmental conscious machining has been spread all over the world. Minimizing the power consumption in the machining phase of a product can save cost and reduce the global warming potential associated with machining. More energy usage in machining phase means more CO2 equivalent emissions in environment. Several researchers have worked in the area of machining to minimize power consumption. Gutowski et al.3 performed an environmental examination of a machining process. The study revealed that out of total energy very less amount of energy is required for cutting. Munoz et al.4 developed an analytical approach to demonstrate the environmental impacts of the machining operations. The study was based on power consumption,cutting mechanics and coolant flow. This study exposed that power consumption utilized by a machining process depends upon complexity involved in geometry, material and coolant selection.Kordonowy 5 performed energy calculations for various machine tools. This work was based on injection molding, manual milling,automated milling and automated lathe machine. The study presented a complete examination of power consumption utilized in different phases of machine. Drake et al.6 suggesed a framework to describe power consumption in machine tools. The framework suggested a six steps process to characterize energy consumption. The study concluded that most of the energy consumption was used in machine controller and 35% of the total energy was used by spindle.Diaz et al.7 conducted an analysis of machine tool to develop more efficient energy consumption strategy. The study developed a method of using specific energy as a function of process rate. The proposed method provides accurate energy consumption without actually measuring power demand. In another study Diaz et al.8 presented design and operation strategies to reduce energy consumption. The study was conducted using kinetic energy recovery system (KERS),process parameter selection strategy and web-based energy estimation tool. The study exposed that KERS has potential of saving 25% of energy. Kara et al.9 developed an empirical model to establish the relationship between energy consumption and process parameters. This model was verified on different milling and turning machines. The proposed model predicts energy consumption with an accuracy of 90%.DOI: 10.1007/s12541-013-0122-yShan et al.10 presented energy saving and emission reduction strategies by focusing on energy involved in mechanical equipment.Jawaid et al.11 conducted an experimental investigation to evaluate the machinability of Ti-6246 alloy under dry condition. Experimentation was conducted at constant depth of cut with four different levels of cutting speed using uncoated cemented carbide tools. The study revealed that finer grain size tools performed better than the tools with coarser grain size. Abrasion wear mechanism was observed at the flank face of the cutting insert. Corduan et al.12 examined the wear mechanisms of PCD (polycrystalline diamond), CBN (carbon boron nitride) and TiB2 coated carbides for the machining of titanium-based alloys. The study pointed out that the PCD tools performed best at cutting speed of 150m/min. CBN tools were suitable for finishing cutting conditions. Whereas, TiB2 coated inserts worked well under 100m/min cutting speed. It has been observed that adhesion and diffusion were the dominant wear mechanisms. Hwang et al.13 evaluated machinability of Al 6061 using vegetable oil based MQL (Minimum Quantity Lubrication) machining and water soluble wet machining. The study utilized Taguchi method and revealed that cutting conditions have significant role on cutting forces generated during machining. Elmagrabi et al.14 conducted an experimental study to investigate the performance of the coated and uncoated carbide tools under dry conditions. The experimentation was focused on slot milling of Ti 6Al 4V. The study revealed that PVD coated carbide tool has high life. Surface roughness was more dependent on feed rate and depth of cut.This paper presents an experimental study and analysis to evaluate the performance of coated and uncoated carbide inserts under different machining environments. In literature, there is very limited research work available with respect to the power consumption in machining Titanium alloys. In the presented study; performance of cutting inserts based on the tool wear were examined carefully with respect to the energy consumption during each machining test. This contribution of energy consumption can be a useful source of information for sustainability computations.2. Experimental SetupMachining tests were carried out on a CNC Turning Center. Titanium alloy Ti 6Al 4V was selected as a workpiece material. The nominal chemical composition of the workpiece material is given in Table 1. Experiments were conducted utilizing two types of cuttinginserts. The nominal specifications for these inserts are given in Table 2. Experiments were performed under the conditions shown in Table 3 by utilizing a constant depth of cut and machining length. Dimensions of raw material work piece are 300mm in length and 95mm in diameter.Mitutoyo Roughness Tester SJ 201P was used for the measurement of surface roughness. To minimize the experimental error each measurement of surface roughness was repeated four times and only the average values were reported. Tool flank wear was measured with a toolmaker microscope. Scanning electron microscopy was utilized to study the major wear mechanisms. Kistler Multi Channel Dynamometer was utilized for measuring the cutting forces generated during drilling operations. PS3500 power data logger has been used to capture the power utilized during each cutting test. Fig. 1 shows schematic representation of the experimental setup.3. Results and Discussion3.1. Surface roughness analysisSurface roughness values were recorded for all of the turning tests performed by using both coated and uncoated inserts. Surface roughness values, average of three measurements, have been plotted for both cases as shown in following Figs. below. Figs. 2 and 3 compares the roughness values for coated and uncoated tools at feed 0.1mm/ rev under dry, mist and flood environments.Table 1 Nominal chemical composition of Ti 6Al 4V (wt. %) Element %Element %CAlFeV<0.085.5–6.75<0.43.5–4.5HNOTi< 0.05< 0.01< 0.2Balance Table 2 Cutting Inserts propertiesCutting Inserts1.Coated Carbide - TCMT 16 T3 04-MM 1105•The substrate consists of a hard fine-grained WC with 6% Co for high hot hardness and good resistance against plastic deformation •The new thin PVD TiAlN coating with excellent adhesion, also on sharp edges, guarantees toughness, even flank wear and outstanding performance in heat resistant super alloys2.Uncoated Carbide - TCMT 16 T3 04-KM H13A •Combines good abrasive wear resistance and toughness for medium to rough turning of heat resistance steel and titanium alloysTable 3 Cutting ConditionsMachining ParametersDepth of cut (mm)Cutting Speed (m/min)Feed (mm/ rev)Length to machine (mm)0.8mm ConstantThree levels (30-60-90)Two levels (0.1-0.2)120Machining Environment-Dry-Mist-FloodFig. 1 Experimental SetupAt low cutting speed of 30m/min under dry conditions the observed roughness (Ra) values for both coated and uncoated inserts were approximately the same. H owever, at cutting speed of 30m/min uncoated insert showed better surface quality for both mist and flood conditions. At cutting speed of 60m/min for dry condition both inserts performed in a similar manner. But at 60m/min coated inserts provided more roughness than the uncoated inserts for both mist and flood environments. At 60m/min the lowest value of surface roughness was obtained using uncoated insert under mist condition. Similar trends but with better surface finish were observed at 90m/min for both coated and uncoated inserts. Klocke,15 Zhang,16 and Jiang 17 pointed out that at higher cutting speed, cutting force decreases and cutting temperature increases. Uncoated carbides cannot withstand high temperature and results in rapid adhesion and diffusion wear. TiAlN coating resists heat to extend tool life by lowering coefficient of friction.Figs. 4 and 5 represents the comparison of the roughness (Ra)values for coated and uncoated tool at higher feed of 0.2mm/ rev for dry, mist and flood environments. Similar trend was noted before.18,19For dry condition coated tool performed better than uncoated tool for all cutting speeds of 30, 60 and 90m/min. For mist and flood environments coated tool gave high roughness values at low cutting speed i.e. 30m/min. Coated inserts gave good result at cutting speeds of 60 and 90m/min. Uncoated inserts performed better than coated inserts at low cutting speed for both mist and flood condition.It can be seen that coated inserts provides comparatively fair results at higher cutting speeds this might be because of the wear and heatresistant nature of TiAlN coating. H owever, uncoated inserts were found superior for low cutting speeds because of relatively low cutting temperature at low cutting speed. Better surface finish was obtained under dry condition for both coated and uncoated inserts. Similar trends were onserved by Seah et al.20 when machining steel alloys. Their study revealed that coolant shifted crater wear towards the cutting edge.3.1.1 Statistical analysis of surface roughnessThe surface roughness data was also analysed by using analysis of variance (ANOV A) method. ANOV A technique is very useful statistical method for efficient decision-making. ANOV A divides total variation into responsible sources. The study utilized Design Expert 8to analyse surface roughness data statistically. ANOV A was implemented to determine the percentage contribution of process parameters on surface roughness. Outcome of ANOV A results in F value that makes results significant from each other. H igher F value shows that variation in that parameter causes significant change in the response parameter.21 Table 4 shows that except for feed rate none of the factors contributed considerably towards the surface roughness. The model F value of 140.06 implies that the model is significant. In the present study A, B, C, D, AB, AC, AD, CD, ABC, ABD and ABCD were significant model terms.Fig. 6 shows different statistical graphs obtained from surface roughness data. H alf-normal probability plot is a powerful graphical tool that points out at important factors and their interactions.22 As shown in Fig. 6(a), a list of effects and their interactions were reportedbased on their magnitudes. Insignificant factors appear on or close toFig. 2 Surface roughness, f =0.1mm/rev, Coated tools under dry, mist and flood environmentsFig. 3 Surface roughness, f =0.1mm/rev, Uncoated tools under dry,mist and flood environmentsFig. 4 Surface roughness, f =0.2mm/ rev, Coated tools under dry, mist and flood environmentsFig. 5 Surface roughness, f =0.2mm/ rev, Uncoated tools under dry,mist and flood environmentsthe near zero line. It was observed that factor B (feed rate) is the most important factor for the presented study.The normal probability plot graphically represents normal distribution of data set. Fig. 6(b) represents normal distribution of surface roughness data set. A straight line shows data followed normal distribution approximately. Residual vs. run plot is a special scatter plot that shows different drifts in data. In residual vs. run plot each residual is plotted against experimental run order. Fig. 6(c) shows residual values of surface roughness data against experimental runs. Residual data was found randomly distributed over experimental runs.3.2 Cutting Force AnalysisThe cutting forces significantly control cutting temperature, tool wear, tool life, surface integrity and distortions in workpiece, fixtures and cutting tool due to instabilities in machining dynamics. In Fig. 7, It was observed as a general trend that cutting forces decrease with increasing cutting speed up to a certain range, and after passing that range cutting force again starts increasing.Table 4 Results of ANOV A for surface roughnessCutting Parameters Sum of Squares df Mean Square F-Test Contribution (%) Model149.6135 4.27140.0698.55 A-Cutting Speed 1.1220.5618.350.74B-Feed142.611142.614672.8393.94 C-Coolant0.4020.20 6.470.26 D-Cutting Tool Material0.5510.5518.130.36AB0.3520.18 5.780.23AC0.6240.16 5.110.41AD 1.0620.5317.380.70BC0.1820.09 3.000.12BD0.0210.020.750.02CD0.2120.10 3.430.14ABC0.3140.08 2.500.20ABD0.8620.4314.070.57ACD0.1140.030.890.07BCD0.0720.03 1.120.05ABCD0.3940.10 3.200.26 Error 2.20720.03-- 1.45 Total151.81107----100.00Fig. 6 Statistical analysis of surface roughness (a) Half-normal plot (b) Normal plot of residuals (c) Residuals vs. runFigs. 7(a) and (b) show that at low feed of 0.1mm/rev cutting force reduced slightly for both uncoated and coated tools when cutting speed was increased from 30m/min to 60m/min. H owever cutting force increased again when cutting speed was raised from 60m/min to 90 m/min. This variation in cutting force can be attributed to built up edge (BUE) phenomenon and cutting temperature behavior. Previous studies 16,17 revealed that temperature in cutting zone is directly related to the cutting speed. H igher cutting velocities generate elevated temperatures in cutting zone that enhances thermal softening of workpiece material. Built up edge (BUE) formation is based on cutting conditions and combination of workpiece and cutting tool material.Reduction in cutting forces points out that built up edge increases effective rake angle resulting in lower cutting forces. Fang and Wu 23also observed reduction in cutting forces with increase in cutting speed for machining Ti6Al4V and Inconel 718. Other studies 15,24 also revealed that cutting force decreases with increase in cutting speed. The present study also revealed that the cutting force was lower, when cutting speed was close to the range of 60m/min. Komanduri and Reed 25 also found that uncoated carbides exhibit excessive tool wear above 60m/min. The cutting force increased at higher cutting speed of 90m/min because at higher cutting speed there is no built up edge (BUE) formation.The cutting force measurement in Fig. 7(a) and (b) also revealed that uncoated inserts have generated less cutting forces than the coated inserts at low cutting speed of 30m/min and feed of 0.1mm/rev. This higher magnitude of cutting force points out at potential of high tool wear in coated inserts at low cutting speeds. H owever less cutting forces were observed for coated inserts at cutting speeds of 60-90m/min. This shows that coated inserts performed comparatively better at higher cutting speeds. Adhesion and abrasion mechanisms were found at lower cutting speeds. H igher cutting speeds and elevated cutting temperature favors diffusion to be a dominant tool wear mechanism.Diffusion wear limits the performance of uncoated carbides at higher cutting speeds. Slightly higher cutting force was observed in uncoated tool at cutting speed of 90m/min indicating unstable wear rate. Similar behavior was observed in case of coated inserts. Higher cutting speeds can produce elevated temperature at cutting zone but TiAlN coating is heat and wear resistant in nature. Groover 26 also commented on the relationship of cutting force with shear area in the cutting zone. Low cutting forces for coated carbide tools point at less shear area in cutting zone. Less shear area means high value of shear plane angle that is favorable for easy machining because of less power consumption and temperature in cutting zone. Figs. 7(a), (b), (c) and (d) states that increase in feed results in higher cutting forces for both uncoated and coated carbides.Figs. 7(a) and (b) shows cutting force for coated and uncoated inserts under dry, mist and flood conditions. At low feed of 0.1mm/rev and cutting speed of 30m/min forces produced in dry conditions were lower than forces obtained in mist and flood conditions. Similar cutting force behavior was observed for flood cooling at feed of 0.2mm/rev.The findings related to negative impact of flood cooling was against the common belief of coolant application. A possible explanation of this finding could be that by introducing the coolants in cutting zone reduces the temperature of cutting tool as well as workpiece material.This cooling effect of workpiece material reduces thermal softening tendency. As a result higher cutting forces are generated in order to cut material. Seah et al.20 also found similar behavior of flood cooling when machining AISI 1045 and AISI 4340 steel grades using uncoated tungsten carbides. H is study revealed that flood cooling favors crater wear to grow near the cutting tip that makes it much weaker. Beno et al.27 also found similar results of increasing cutting force under MQL for machining Wasaloy.Figs. 7(a) and (b) show that coated inserts generated less cuttingforce at higher cutting speeds. The lowest cutting force was observedFig. 7 Cutting force at different cutting speeds under dry, mist and flood cooling strategies (a) Uncoated inserts, f =0.1mm/rev (b) Coated inserts,f =0.1mm/rev (c) Uncoated inserts, f =0.2mm/rev, and (d) Coated inserts, f =0.2mm/revwith coated insert under dry condition at 60m/min cutting speed.H ighest cutting force was observed with coated insert under mist condition at 30m/min cutting speed. It concludes that TiAlN coated inserts were better for higher cutting speed selection. H igher cutting speed generates high cutting temperature in the cutting zone that allows diffusion wear mechanism to start rapidly. TiAlN coated tools performed better at higher cutting speeds due to the formation of highly dense Al 2O 3 protective layer. This protective layer prevents diffusion wear mechanism at higher cutting speeds. Figs. 7(c) and (d) depict the generated cutting forces at constant feed of 0.2mm/rev for three different levels of cutting speed. It states that uncoated inserts generated more cutting force at all levels of cutting speeds. However,performance was equally good for uncoated at 90m/min cutting speed under flood environment when compared with coated inserts. At higher feed level of 0.2mm/rev the lowest cutting force was observed with coated insert under dry condition at 60m/min cutting speed. The general trend of cutting force was that it decreased with increasing cutting speed in both uncoated and coated inserts, whereas it increased with further increase in cutting speed.3.3 Power and Energy ConsumptionPower and energy consumption has also been observed for both coated and uncoated inserts. Energy consumption was compared for both inserts to examine which tool is more energy efficient. Fig. 8displays a sample calculation of power and energy consumed during a turning experiment for specific cutting conditions under dry condition. Based on the sample calculation shown in Fig. 8 energy consumption has been computed for all of the cutting tests. Fig. 8 also shows that power demand increases with increase in cutting speed butmachine time reduces due to variation in workpiece diameter. For the current study, the cutting speeds were kept constant by varying spindle speed, RPM, to compensate for the reduction in workpiece diameter.The change in RPM changed the machining time for different cutting speeds. In present study machining length was kept constant for cutting experiments. It can be observed that change in spindle speed influences machining time.For appropriate energy comparison in machining tests specific energy consumption was calculated with respect to material removal rate (mm 3/min). Figs. 9, 10 and 11 show that more energy was consumed at low feed of 0.1mm/rev. Machining with low feed ratetakes more time because of slower tool movement, however similarFig. 8 Power and Energy consumption in Dry cutting (a) Uncoated tool, f =0.1mm/min (b) Coated tool , f =0.1mm/min (c) Uncoated tool, f =0.2mm/min (d) Coated tool, f =0.2 mm/minFig. 9 Specific energy consumption by uncoated and coated inserts at cutting speed of 30m/min under dry, mist and flood conditionslength can be machined in less time using higher feed rates. As less time was involved in machining at high feed rate that result in reduced energy consumption. Lower cutting speeds resulted in high energy consumption when constant machining length was used. It was observed that this reduction in energy consumption was attributed to machining time. The machining time was reduced due to variation of workpiece diameter in order to adjust spindle speed, RPM. At cutting speed of 30m/min, coated inserts consumed more power than the uncoated inserts.At cutting speed of 30m/min and feed of 0.1mm/rev it was observed that mist and flood consumed more power. H igher power consumption for mist and flood is due to higher cutting forces and power drawn by hydraulic pump. At cutting speed of 60m/min dry environment consumed minimum energy for both feed levels. At higher cutting speed of 90m/min mist environment showed potential of better heat dissipation from the cutting zone at both feed levels. Flood environment gave higher energy consumption in most of the cases which shows that high cutting forces were produced under flood conditions. Comparatively less energy consumption was observed for coated inserts at cutting speeds of 60m/min and 90m/min. This is linked with cutting forces produced by coated inserts. H oweveruncoated inserts showed comparatively better performance at low cutting speed of 30m/min.The general trends obtained for energy consumption can be summarized as follows: higher energy consumption was obtained at low cutting speed due to variation in diameter when machining length was kept constant. It is because machining time reduced when workpiece diameter changed. The coated carbides under mist condition provided comparatively less energy consumption because of efficient control of friction in cutting zone. TiAlN coating is also helpful in reducing coefficient of friction. TiAlN coated tools showed comparatively less energy consumption in all cases, especially at higher cutting speeds. H igher feed rate results in less energy consumption.3.4 Tool Wear AssessmentThe interaction between tool, workpiece and chip results in different types of tool wear. The literature classifies these types as adhesive wear, abrasive wear, delamination wear, diffusion wear, microchipping,fatigue, notch, gross wear and plastic deformation.28,29 These wear mechanisms are dominant on the rake face as a crater wear and flank wear on the flank face. Under normal machining conditions flank wear predominate crater wear and defines the failure criteria for cutting tools.Maximum values of flank wear were measured using a tool maker microscope. The values obtained for uncoated and coated inserts under dry condition are plotted in Fig. 12. It can be observed that flank wear rate is very rapid for coated carbides. H igher flank wear rate was observed for higher feed rate under all cutting environments. Tool coatings are useful in reducing the coefficient of friction between chip and tool. By reducing, the friction coefficient heat generation during metal cutting operation can also be reduced. This phenomenon can increase the tool performance and tool life. Higher flank wear rate in uncoated insert at high cutting speed and feed points out at high amount of heat generation for these cutting conditions. Improved heat transfer can be obtained using mist and flood environments.The coated insert provided the highest flank wear at high cutting speed of 90m/min and feed of 0.2mm/rev. This points out the fact that titanium alloys have low thermal conductivity as a result the heat generated during the machining operation stays in the region of cutting.As the cutting environment was dry there were less chances of heat dissipation. Due to the excessive heat generation and friction phenomenon coating delamination and abrasion were responsible for large wear zone at flank face of the coated insert Experimentationshowed good results for the same cutting condition under mist andFig. 10 Specific energy consumption by uncoated and coated inserts at cutting speed of 60m/min under dry, mist and flood conditionsFig. 11 Specific energy consumption by uncoated and coated inserts at cutting speed of 90m/min under dry, mist and flood conditionsFig. 12 Flank wear, Coated and Uncoated tool under Dry environmentflood environments. The experiments revealed that improved heat dissipation could reduce the coating delamination, which can result in low flank wear.Fig. 13 represents the plotted results for flank wear of coated and uncoated inserts under mist conditions. Under mist condition results obtained for flank wear were better than the dry conditions. Another observation was related to the coated inserts that they performed better than uncoated tools at higher cutting speed of 60 and 90m/min.However, uncoated tools were good for low cutting speed of 30m/min. The micrographs shown in Figs. 15-20 point out at the underlying wear mechanisms for both uncoated and coated tools. The particles of workpiece material were found attached at the nose and flank face ofthe cutting tool. These small welded particles have potential to form built up edge (BUE).Fig. 14 shows flank wear of coated and uncoated inserts under flood conditions. Flank wear results at low cutting speed 30m/min for flood environment were better than mist especially for coated inserts. Coated inserts comparatively performed better than uncoated tools at higher cutting speed of 90m/min. Scanning electron microscopy presented in the later part of the paper is in agreement with the values obtained in Fig. 14. The particles of workpiece material were found attached at the nose and flank face of the cutting tool for both coated and uncoated tools. Similar behavior of workpiece material was reported for flood environment.3.4.1 Wear mechanisms in uncoated and coated carbides at cutting speed of 30m/minIt has been observed that adhesion, diffusion and abrasion were the main wear mechanisms for Ti-6Al-4V alloy, as was reported earlier,11,12Scanning electron microscope (SEM) has been utilized to study the underlying wear mechanisms present in turning of titanium alloys. Fig.15 shows the SEM micrographs of wear at flank face of uncoated insert under cutting speed of 30m/min and feed of 0.1mm/rev using dry,mist and flood environments. Adhesion and abrasion were found as major wear mechanisms in uncoated carbide tools. It was also observed that wear rate was much higher for dry environment. The combination of high temperature and chemical reactivity creates a friendly environment for the adhesion and diffusion to start at rapid rate. Fig. 17shows that diffusion was also present in coated inserts under dry conditions. But for mist and flood environment diffusion was not observed clearly. As titanium, alloys have very high chemical reactivity that results in an extreme wear at flank face. The particles of workpiece material were found attached at the nose and flank face of the cutting tool. The main wear mechanism responsible for this behavior is adhesion. Adhesive forces between the tool and workpiece material result in adherence of small particles at cutting edge. These small welded particles have potential to form built up edge (BUE). Built up edge (BUE) was observed in the shown micrographs.SEM micrographs of coated and uncoated inserts revealed thatFig. 15 SEM images of wear at uncoated carbide tool at Vc =30m/min and f =0.1mm/rev, (a) Dry (b) Mist (c) FloodFig. 13 Flank wear, Coated and Uncoated tool under Mist environmentFig. 14 Flank wear, Coated and Uncoated tool under Flood environment。
2017外交学院翻译硕士考研准备看什么参考书外交学院翻译硕士参考书很多人都不清楚,这里凯程外交学院翻译硕士王牌老师给大家整理出来了,以供参考:英语:1、Bassnett, Susan.《翻译研究》Translation Studies, 外教社, 2004.2、Gentzler, Edwin.《当代翻译理论(第二版修订本)》Contemporary Translation Theories, 外教社,2004.3、马会娟、苗菊编.《当代西方翻译理论选读》, 外语教学与研究出版社,2009年。
4、Joan Pinkham 、姜桂华著:《中式英语之鉴》,外语教学与研究出版社,2000年。
5、庄绎传著:《英汉翻译简明教程》,外语教学与研究出版社,2002年。
6、叶子南著:《高级英汉翻译理论与实践》,清华大学出版社,2001年。
7、罗进德主编:《非文学翻译理论与实践》,中国对外翻译出版公司,2004年。
俄语:1、蔡毅等编:《俄译汉教程(增修本)》上册,外语教学与研究出版社,2006年。
2、周允、王承时编:《汉译俄教程》,外语教学与研究出版社,1981年。
3、吴克礼主编:《俄苏翻译理论流派述评》(下编),上海外语教育出版社,2006年。
法语:1、许钧:《翻译论》,湖北教育出版社,2003年。
2、曹德明(总主编):《全国翻译专业资格(水平)考试指定教材》(“法语笔译三级”和“法语笔译二级”的相关教材),外文出版社,2005年。
德语:1、刘宓庆:《当代翻译理论》,中国对外翻译出版公司,2001年。
2、刘宓庆:《文体与翻译》,中国对外翻译出版公司,1998年。
3、罗新璋编:《翻译论集》,商务印书馆,1984年。
4、Amman, M.: Grundlagen der modernen Translationstheorie. Heidelberg, 1989.5、Gerzymisch-Arbogast, H.: übersetzungswissenschaftliches Prop deutikum. Tübingen (Francke)1994.6、Koller, W.: Einführung in die übersetzungswissenschaft. 4. Auflage. Heidelberg (Quelle & Meyer) 1992.7、Nord, C.: Einführung in das funktionale übersetzen. Am Beispiel von Titeln und überschriften. Tübingen/Basel (Francke) 1993.8、Reiss, K.: Möglichkeiten und Grenzen der übersetzungskritik. Kategorien und Kriterien f ür eine sachgerechte Beurteilung von übersetzungen. München (Huber) 1986.9、Seleskovitch, D.: Der Konferenzdolmetscher. Heidelberg (Julius Groos) 1988.10、Snell-Hornby, M.(Hrsg.): Handbuch der Translation 2. Auflage.Tübingen (Stauffenburg) 1999.日语:1、许钧:《翻译概论》,外语教学与研究出版社,2009年3月。
U1: 1. 他对这次面试中可能提到的问题做好了准备。
(confront)He has well prepared answers to the questions that he might confront with in the interview.2. 他悲惨的遭遇深深打动了我们,使我们几乎哭出声来。
(touch)His sad story touched us so deeply that we nearly cry.3. 他们俩手挽着手沿着河边散步,有说有笑。
(hand in hand)They walked hand in hand along the river, chatting and laughing.4. 听到这令人激动的消息之后,他眼睛里涌出欢乐的泪水。
(well up)Tears of joy welt up in his eyes after hearing this exciting news.5. 上海人容易听懂苏州话,因为上海话和苏州话有许多共同之处。
(in common)The people of SH can understand Suzhou dialect easily as they have many things in common.6. 亨利和妻子正在考虑能不能在3年内买一幢新房子。
(look into)Henry and his wife are looking into the possibility of buying a new house.7. 女儿再三请求到国外去深造,他最终让步了。
(give in to)He finally gave in to his daughter repeated request studying abroad.8. 我们在动身去度假之前把所有的贵重物品都锁好了。
(lock away)We have locked all the expensive things away before leaving for the holiday.9. 虽然咱们分手了,但我希望咱们依然是好朋友,像以前一样互相关心,互相帮助。
跨考独家整理最全翻硕考研知识资料库,您可以在这里查阅历年翻译硕士考研真题和知识点等内容,加入我们的翻硕考研交流群还可以获得翻硕学长免费答疑服务,帮你度过最艰难的考研年。
以下内容为跨考网整理,如您还需更多考研资料,可选择翻硕考研一对一咨询进行解答。
2015年考研已经结束,相信考生们现在都是在休息或者嗨皮吧。
跨考教育会在考试之后第一时间整理各个学校MTI的2015年考研真题,以方便广大考生做参考。
以下是跨考网翻译硕士小编整理的网络回忆版2015年考研郑州大学翻译硕士真题,其中包含翻译基础、百科应用文、翻硕英语作文等。
翻译基础:亚健康诗经外交途径跨境避税独生子女费非物质文化遗产海淘黑车食品添加剂转基因作物FDI APECterritary resourceconsumer confidenceflight data jont miliyary nuclear non-proliferation reserve currencybudget deflict百科:应用文以一名大四学长的身份在新生交流会上讲述本专业学习的重要性大作文写议论文清末国学大师俞樾和重臣曾国藩到玄武湖赏荷,他们各自坐了小船下到湖里,船并无差异,但是曾国藩一个姓张的手下为了凸显曾国藩的尊贵,竟然弄了一顶小帷帐罩在小船上,以避免暴晒,但由于小帷帐会被高举的荷叶牵绊,因此,这只小船只能绕荷花而行,而俞樾=虽然顶着烈日,却能够径入藕花深处,与荷花零距离接触。
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机电工程学院毕业论文外文资料翻译论文题目电动汽车燃料电池建模与分析研究译文题目: Renewable Energy学生姓名:朱庆涛学号: 20074740216专业班级:车辆工程0702指导教师:李友才正文:外文资料译文附件:外文资料原文指导教师评语:签名:年月日正文:外文资料译文文献出处:ELSEVIER杂志可再生能源这是一个评价质子交换膜燃料电池的应用模型摘要:在文献里几个模型已经被建立来体现质子交换膜燃料电池的性能。
这些模型根据复杂程度的不同可以分为主要的两类:机理模型和半经验模型。
机理模型来自于电化学、热力学、流体力学等,详细的描述了燃料电池的工作过程。
机械的方案的主要缺陷是模型非常复杂,需要的参数知识难于获得。
另一方面半经验模型容易获得也能在工程软件上正确的反映燃料电池系统的的性能。
在这篇文章里将要建立一个全新的半经验的模型比以往文献里出现的任何模型都要简单,这个模型划分成使用半经验方程和线性二次方程来计算的经验结果系数。
这模型可用在小型分布式发电系统的性能评估,以及车辆燃料电池和便携式电子产品的设计中。
1 介绍燃料电池是在电介质和极板的帮助下使氧和氢气结合产生电流的电化学设备。
在不同类型的燃料电池中,质子交换膜燃料电池也称为聚合物电介质膜燃料电池是燃料电池发展的最前沿技术。
质子交换膜燃料电池是一种清洁的能量转换装置。
因为这种燃料电池的主要产物只有水、热和电能。
在小于100°C的工作温度时达到4065%的效率。
高达0.8W/cm2能量密度。
这些特征使质子交换膜燃~料电池成为最有前途的技术。
对未来的发展有许多应用。
例如:便携式电子产品,分布式能量发生器和汽车等[2]。
一个可靠的数学模型需要容易理解且能够反映燃料电池系统性能的参数;在分析和设计模型时能够节省时间和开支。
为此不同的模型已经在文献[3]里建立。
在文献里被提议的几个模型都有介绍,它给人展现根据应用条件选择燃料电池模型的标准。
质子交换膜燃料电池模型可以基本的划分为两大类:机理模型和半经验模型。
机理模型是基于电化学、热力学、流体力学一般是高次方程,需要难于掌握的参数知识如傅里叶变换,湿度水平、隔膜、电极活化催化剂层厚度。
另一方面半经验模型比机理模型容易掌握也能够正确的反映在工程中。
例如小的分布式发电系统便携式电子产品和汽车。
因此,这种模型将在本文被采纳应用。
一个简单在文献里的半经验模型首先在参考文献[10]中介绍。
一个基于BM系统公司生产的BM IV燃料电池静态模型已经被提出。
这个模型属于机理模型。
用机理模型产生结构方程,然后通过使用衰退技术得到参数满足实验数据。
主要文献是[10]计算燃料电池工作的主要变量的半经验模型。
例如工作温度、电极局部压力、燃料电池电流。
为了扩大基于BM Iv电池的模型与其他类型被提出在文献[17]的模型的应用。
一个不同的半经验模型叫做普通静态电化学模型。
这模型是基于文献[45,19]基于聚合体隔膜反应的实验数据。
然而文献[19]的数据是从一种特殊的燃料电池膜获得的;即DuPont的Nafion117质子交换膜。
特殊燃料电池的流场设计中,不能保证GSSEM能体现不同设计思路的电池的性能。
最近一个经验方程已经被提出在文献[20]在主要工艺参数上模仿燃料电池的电压变化。
模型方程有11个参数。
一个参数电极间液体水的质量必须通过技术条件来估算。
另外其他参数从实验数据中获得。
尽管文献[20]提出的模型和实验数据非常吻合,但是燃料电池电压方程却没有理论依据。
所以假定在受温度影响和局部压力影响下,不能证明文献[20]的数据是全面的。
在这篇文章里,一个全新的半经验模型比目前文献上提出的其他模型计算量要少。
一个新静态模型仅有一个来自于文献[4,10,17]的半经验方程组成,因此有机理基础。
由此可见这个单独的方程有足够的自由度,正确的反映燃料电池参数的变化。
正是这种模型配备燃料电池本身的实验数据能发现和隔膜电阻有关的参数。
希望能达到优于GSSEM的数据匹配。
为了展示被提议模型的优越性;模型的参数和bps一个动力文献上有效参数保持一致,因为不同的运动条件使描述有别于bsp一个动力文献。
这篇文章有如下安排:第二部分介绍燃料电池的工作原理。
第三部分介绍半经验模型,第四部分对模型参数进行鉴定,最后第五部分是结束。
2 燃料电池工作原理一个单体质子交换膜燃料电池主要有两个被固体电解质分开的起催化作用的多孔渗水电极。
这电解液是离子传导聚合体。
在电池的正极,富氢气体在一定压力下供给,这种燃料气体通过多孔渗水电极传播一直到达电极的反应层,释放电子产生质子。
H 2→2H ﹢+2e - (1)在阳极不完全反应释放的电子经外电路到达阴极。
同时两个氢离子经过交换膜到达阴极。
在阴极附近,提供有氧化剂(一般是空气)。
当氧到达电极的反应层和电极产的电子和电解液中的氢离子反映生成水。
所以电解反应的总方程是:O 2 +4H ++4e -→2H 2O (2)电池组的总反应方程式是:2H 2 + O 2→2H 2O+热量 (3) 当电流密度接近0.5A/cm 2时的单电池电压为0.7V 。
所以为了产生有用的电压使用极板把很多电池串联起来形成电池堆。
电极作为为阴极提供氧,为阳极提供能源气体,同样作为电池电极的连接。
需要注意的是水合薄膜是至关重要的因素在燃料电池工作中。
因为氢离子在通过高分子膜时被水分子包围,所以薄膜必须有足够的水来满足离子导电性。
所以隔膜脱水会导致质子的流动阻力增大。
另一方面,过多的水主要在阴极不完全反应生成的水,导致氧在多空电极里的扩散问题。
在这篇文章里假定水控制和水合反应都满足恒稳工作的要求。
3 非线性的PEMFC 模型如果燃料电池反应中的所有化学能都转变成工来使电子在外电路移动。
那时电池输出电压将会和热力学平衡电压相等。
然而这个过程存在的损失取决于燃料电池的电流密度和工作条件(温度,电极接触面的局部压力薄膜湿度)。
在这部分潜在的热力平衡方程和电压损失的观点得来于一个简单的PEMFC 半经验模型. 1.1 热力平衡电压热力平衡电压被文献[11,4]的那斯托方程提出E=E 0+F2RTln []22O H P P (4)R 是气体常量8.314J/Kmol ,F 是法拉第常数96487C ,T 是燃料电池工作温度 K ,Po 2 ,P H 2分别表示氧和氢在接阴极和阳极触反应面的局部压力。
E 0表示在标准压力下的开路可逆电压。
让我们现在讨论条件Po 2 ,P H 2,E 0的方程。
3.1.1 标准压力下的可逆开路电压众所周知E 0是电池电压工作温度T 的函数表示为:E 0 =1.229-0.85⨯10-5(T-298.15) (5) 3.1.2 氧在阴极接触反应层的局部压力。
假设氧化剂是氧和氮的混合物,在燃料电池的工作温度下和水气饱和。
在流道内的全部压力是定值,氧的局部压力的流动方程在文献四中给出。
Pca 是阴极的压力,I 使电流密度,Xh2o 是是水的摩尔份数,XN2是阴极流道内的氮的摩尔份数,值得注意右边指数项非常接近于一。
即使是高的电流密度和低的温度。
例如:电流密度是0.8A/cm 2温度是298K 指数项等于1.002.所以公式6的指数项可以忽略,从而方程可以简化为:O 2+4e -+4H +→2H 2O假定像文献[4 15]中阴极的有效水压等于水汽在温度T 时的饱和压力。
所以:P O 2=P ca ⎥⎥⎦⎤⎢⎢⎣⎡-)291.0exp(X -1832.0ca O H 22T l X N(6)假定氧化剂在阴极流道达到适当的循环,从而氧和氮的摩尔份数之间的关系是常数。
P O 2 = P ca []22N ca O H X -X -1 (7) 假定如在文献[4,10]有效阳极水压等于在温度T 下的静态压力xca OH 2=PcasatOH p 2 (8)假设氧和氮气之间的关系是常数X N 2=β(9)用以上式子可以得到阳极氧的局部压力表达式是2O P =γ(Pca -satOH 2P ) (10)其中γ=β+113.1.3氢在阳极接触反应面的局部压力假定可燃气体是潮湿的纯净氢气,有效阳极水汽压力是饱和水汽压力的百分之五十。
氢的局部压力就是:P H 2 =(0.5satO H 2p ) ⎥⎥⎥⎥⎦⎤⎢⎢⎢⎢⎣⎡-1T l 53.61exp 1334,.1)( (11)现在如(6)在(11)中的指数项接近于1 ,即使对于高电流密度和低的工作温度下,这项也可被忽略,可得:P H 2=(0.5satO H 2p)⎥⎥⎦⎤⎢⎢⎣⎡-11x an O H 2 (12) 因为 x anO H 2=Pansat OH p 5.02 (13)P H 2=p an -0.5psat OH 2 (14)P an 表示阳极的全部压力。
3.1.4热力平衡电压方程现在我们以根据燃料电池温度阴极 阳极压力 水汽的饱和压力获得的热力平衡电压表达式,用(5)(10)(14)中的取代(4)中的得到一个方程:E=1.299-0.85⨯10-3(T-298.15)+4.31⨯10-3T ⨯ []))(()(p p pp sat O H ca satO H an22ln 215.0ln -+-γ (15) E=ε1+ε2T+ε3Tln(P an -0.5P sat O H 2)+ε4Tln(P ca -psat OH 2) (16)ε1=1.4833 (17) ε2 =-0.85⨯10-3+2.155⨯10-5ln γ (18)ε3 =4.31⨯10-5 (19) ε4=2.155⨯10-5 (20)值得注意的是电池中饱和水汽压力可以使用下面的表达式计算 log 10psat OH 2=-2.1794+0.02953(T-273.15)-9.1837⨯10-5(T-273.15)2+1.4454⨯10-7⨯(T-273.15) 3 (21)3.2催化电压损失催化电压损失是产生电压的一部分损失在推动化学反应中电子来自电极的移动。
为了模拟巴拉德马克公司设计的PEM燃料电池的催化电压损失,提出了下面的方程[10]:ηact =ξ1+ξ2T+ξ3Tln(c *O 2)+ξ4Tln(i) (22) 系数j=1~4从实验数据中获得i (A )表示电池电流。
阴极反应层的有效的氧的浓度。
和氧在接触反应层的局部压力有关。
工作温度如下:c *O 2=)(T498exp 5.08P 106O 2-⨯ (23)为了概述燃料电池区别于巴拉德马克思的电池下列的数值是文献[17]的经验参数。
ξ1=-0.948(±0.004) (24)ξ3=(7.6±0.2)⨯10-5 (25)ξ4=-(1.93±0.05)⨯10-4(26)不同于文献[10]是被假定为常数在文献[17]中假定随着燃料电池活动的面积和阳极接触反应层的有效氢气浓度的变化而变化。