外文资料翻译
Electric Power System
Introduction
Electric Power System,components that transform other types of energy into electrical energy and transmit this energy to a consumer.The production and transmission of electricity is relatively efficient and inexpensive,although unlike other forms of energy,electricity is not easily stored and thus must generally be used as it is being produced.
Components of an Electric Power System
A modern electric power system consists of six main components:(1)the power station,(2)a set of transforms to raise the generated power to the high voltages used on the transmission lines,(3)the transmission,(4)the substations at which the power is stepped down to the voltage on the distribution lines,(5)the distribution lines,and(6)the transformers that lower the distribution voltage to the level used by the consumer's equipment.
Power Station The power station of a power system consists of a prime mover,such as a turbine driven by water,steam,or combustion gases that operate a system of electric motors and generators.Most of the world's electric power is generated in steam plants driven by coal,oil,nuclear energyor gas.A smaller percentage of the world's electric power is generated by hydroelectric(waterpower),diesel,and internal-combustion plants.
Transformers Modern electric power systems use transformers to convert electricity into different voltages.With transformers,each stage of the system can be operated at an appropriate voltage.In a typical system,the generators at the power station deliver a voltage of from 1,000 to 26,000 volts(V).Transformers step this voltage up to values ranging from 138,000 to 765,000 V for the long-distances.At the substation the voltage may be transformed down to levels of 69,000 to 138,000 V for further transfer on the distribution system.Another set of transformers step the voltage down again to a distribution level such as 2,400or 4,160 V or 15,27,or 33 kilovolts(KV).Finally the voltage is transformed once again at the distribution transformer near the point of use to 240 or 120 V.
Transmission Lines The lines of high-voltage transmission systems are usually composed of wires of copper,aluminum,or copper-clad or aluminum-clad steel,which are suspend from tall latticework towers of steel by strings of porcelain insulators.By the use of clad steel wires and high towers,the distance between towers can be increased,and the cost of the transmission line thus reduced.In modern installations
with essentially straight paths,high-voltage lines may be built with as few as six towers to the kilometer.In some areas high-voltage lines are suspended from tall wooden poles spaced more closely together.
For lower voltage distribution lines,wooden poles are generally used rather than steel towers.In cities and other areas where open lines create a safety hazard or are considered unattractive,insulated underground cables are used for distribution.Some of these cables have a hollow core through which oil circulates under low pressure.The oil provides temporary protection from water damage to the enclosed wires should the cable develop a leak.Pipe-type cables in which three cables are enclosed in a pipe filled with oil under high pressure(14 kg per sq cm/200psi)are frequently used. These cables are used for transmission of current at voltage as high as 345,000 V(or 345 KV).
Supplementary Equipment Any electric-distribution system involves a large amount of supplementary equipment to protect the generators,transforms,and the transmission linesthemselves.The system often includes devices designed to regulate the voltage or other characteristics of power delivered to consumers.
To protect all elements of a power system from short circuits and overloads,and for normal switching operations,circuit breakers are employed.These breakers are large switches that are activated automatically in the event of a short circuit or other condition that produces a sudden rise of current. Because a current forms across the terminals of the circuit breaker at the moment when the current is interrupted,some large breakers(such as those used to protect a generator or a section of primary transmission line)are immersed in a liquid that is a poor conductor of electricity, such as oil, to quench the current. In large air-type circuit breakers, as well as in oil breakers, magnetic fields are used to break up the current.Small air-circuit breakers are used for protection in shops, factories,and in modern home installations.In residential electric wiring, fuses were once commonly employed for the same purpose.
A fuse consists of a piece of alloy with a low melting point, inserted in the circuit,which melts,breaking the circuit if the current rises above a certain value. Most residences now use air-circuit breakers.
Power Failures
In most parts of the world, local or national electric utilities have joined in grid systems.The linking grids allow electricity generated in one area to be shared with others. Each utility that agrees to share gains an increased reserve capacity, use of larger, more efficient generators, and the ability to respond to local power failures by obtaining energy from a linking grid.
These interconnected grids are large, complex systems that contain elements operated by different groups. These systems offer the opportunity for economic savings and improve overall reliability but can create a risk of widespread failure. For example, the worst blackout in the history of the United States and Canada occurred August 14, 2003, when 61,800 megawatts of electrical power was lost in an area covering 50 million people.(One megawatt of electricity is roughly the amount needed
to power 750 residential homes.)The blackout prompted calls to replace aging equipment and raised questions about the reliability of the national power grid.
Despite the potential for rare widespread problems, the interconnected grid system provides necessary backup and alternate paths for power flow, resulting in much higher overall reliability than is possible with isolated systems .National or regional grids can also cope with unexpected outage such as those caused by storms, earthquakes,landslides,and forest fires, or due to human error or deliberate acts of sabotage.
Power Quality
In recent years electricity has been used to power more sophisticated and technically complex manufacturing processes, computers and computer networks, and a variety of other high-technology consumer goods. These products and processes are sensitive not only to the continuity of power supply but also to the constancy of electrical frequency and voltage. Consequently, utilities are taking new measures to provide the necessary reliability and quality of electrical power, such as by providing additional electrical equipment to assure that the voltage and other characteristics of electrical power are constant.
Voltage Regulation Long transmission lines have considerable inductance and capacitance.When acurrent flows through the line, inductance and capacitance have the effect of varying the voltage on the line as the current varies. Thus the supply voltage varies with the load. Several kinds of devices are used to overcome this undesirable variation in an operation called regulation of the voltage. The device include induction regulators and three-phase synchronous motors(called synchronous condensers), both of which vary the effective amount of inductance and capacitance in the transmission circuit.
Inductance and capacitance react with a tendency to nullify one another. When a load circuit has more inductive than capacitive reactance, as almost invariably occurs in large power systems, the amount of power delivered for a given voltage and current is less than when the two are equal. The ratio of these two amounts of power is called the power factor. Because transmission-line losses are proportional to current, capacitance is added to the circuit when possible, thus bringing the power factor as nearly as possible to 1. For this reason, large capacitors are frequently inserted as a part of power-transmission systems.
World Electric Power Production Over the period from 1950 to 2003, the most recent year for which data are available, annual world electric power production and consumption rose from slightly less than 1 trillion kilowatt-hours(kW.h) to 15.9 trillion kW.h. A change also took place in the type of power generation. In 1950 about two-thirds of the world’s electricity came from steam-generating sources and about one-third from hydroelectric sources.In 2003 thermal sources produced 65 percent of the power, but hydropower had declined to 17 percent, and nuclear power accounted for 16 percent of the total. The growth in nuclear power slowed in some countries,notably the United States, in response to concerns about safety. Nuclear
plants generated 20 percent of U.S. electricity in 2003; in France, the world leader, the figure was 78 percent.
Conservation
Much of the world’s electricity is produced from the use of nonrenewable resources, such as natural gas, coal, oil, and uranium. Coal, oil, and natural gas contain carbon, and burning these fossil fuels contributes to global emissions of carbon dioxide and other pollutants. Scientists believe that carbon dioxide is the principal gas responsible for global warming, a steady rise in Earth’s surface temperature.
Consumers of electricity can save money and help protect the environment by eliminating unnecessary use of electricity, such as turning off light when leaving a room. Other conservation methods include buying and using energy-efficient appliances and light bulbs, and using appliances, such as washing machines and dryers, at off-peak production hours when rates are lower. Consumers may also consider environmental measures such as purchasing “green power” when it is offered by a local utility.”Green power”is usually more expensive but relies on renewable and environmentallyfriendly energy sources, such as wind turbines and geothermal power plants.
电力系统
介绍
电力系统把其它形式的能源转化为电能并输送给用户。尽管不同于其它形式的能源，电能不容易储存，一旦生产出来，必须得到使用，但是电力的生产和传输相对高效和廉价。
电力系统的组成
当今的电力系统由六个主要部分组成：电站，升压变压器（将发出来的电升压至传输线所需高电压），传输线，变电站（电压降至配电线电压等级），配电线路和降压变压器（将配电电压降至用户设备使用的电压水平）。
电站电力系统的电站包括原动机，如由水，蒸汽驱动的涡轮，或者燃烧气体操控的电动机和发电机系统，世界上大多数的电能由煤炭、石油、核能或者燃气驱动的蒸汽发电厂产生。少量电能由水力，柴油和内燃机发电厂产生。
变压器现代电力系统使用变压器把电能转换为不同的电压。有了变压器，系统的每个阶段都能在合适的电压等级下运行。在典型的系统中，电站发电机发出的电压范围是1000伏到26000伏。变压器把电压升至138000到765000伏后，送至主传输线上。因为对于长距离传输，电压越高，效率越高。在变电站，电压被降至69000到138000伏，以便在配电系统中传输。另外一组变压器把电压进一步降至配电等级，如2400到4160伏，或者15，27，33KV。最终，在使用端，经配电变压器，电压再次被降至240V或120V。
传输线高压传输系统通常由铜线、铝线或者镀铜、镀铝的钢线组成，它们悬挂在高大钢格构塔架上成串的
瓷质绝缘体上。由于含镀层钢线和铁塔的使用，增大了塔与塔之间的距离，降低了传输线的成本。在当前的直线安装中，每公里高压线只需建立6个铁塔。在一些地区，高压线悬挂于距离较近的木质电线杆上。
对于低压配电线路，更多的使用木质电线杆，而不是铁塔。在城市和一些地区，明线存在安全危险或者被认为影响美观，所以使用绝缘地下电缆进行配电。一些电缆内核中空，供低压油循环。油可以为防止水对封闭线路的破坏提供临时保护。通常使用管式电缆，三根电缆放入线管中，并填满高压油。这些电缆用于传输高达345KV的电流。
辅助设备每个配电系统包含大量辅助设备来保护发电机、变压器和传输线。系统通常还包括用来调整电压或用户端其它电力特性的设备。
为了保护电力系统设施，防止短路和过载，对于正常的开关操作，采用断路器。断路器是大型开关，在短路时或者电流突然上升的情况下自动切断电源。由于电流断开时，断路器触点两端会形成电流，一些大型断路器（如那些用来保护
发电机和主输电线的断路器）通常浸入绝缘液体里面，如
油，以熄灭电流。在大型空气开关和油断路器中，使用磁场来削弱电流。小型空气开关用于商场，工厂和现代家庭设备的保护。在住宅电气布线中，以前普遍采用保险丝。保险丝由熔点低的合金组成，安装在电路中，当电流超过一定值，它会熔断，切断电路。现在绝大多数住宅使用空气断路器。
供电故障
世界上大多数地方，局部或全国电力设施都连成电网。电网可以使发电实现区域共享。同意共享的每个电力企业可以获得不断增加的储备功率，使用更大、效率更高的发电机，从电网中获取电能以应对局部电力故障。
互联的电网是大型复杂系统，包括被不同组织操控的部分。这些系统可以节约开支，提高整体可靠性，但是也带来了大范围停电的风险。例如，2003年8月14日，美国和加拿大发生了历史上最严重的停电事故。当时，这个区域61800兆瓦的电力供应中断，五千万人口受到影响。（一兆瓦大约可以满足750居民的用电需求）。停电事件迫切要求更新老化设备，提出关于全国电网可靠性的问题。
尽管存在大范围停电危险，互联电网提供了必要的备份措施和供替换的线路，相对于孤立系统，其整体可靠性要高得多。国家或地区电网还可以应对由暴风雨、地震、泥石流、森林火灾、人员操作错误或者蓄意破坏造成的意外停电。
供电质量
近年来，越来越多的精密复杂生产过程、计算机和网络及许多高科技消费品都使用电力为其提供能量。这些产品和生产过程对于供电的连续性和电压、频率的恒定性很敏感。于是，相关部门正采取新措施来保证供电的可靠性和质量。如提供附加的电气设备来保证电压和电能其它特性保持恒定。
电压调整长距离传输线存在的电感和电容不容忽视。当电流流过线路时，随着电流的变化，电感和电容会对线路电压产生影响。这样，供电电压会随负荷变化。运行中，有几种设备用来克服这个波动，被称为电压调整。这些设备包括感应调节器、三相同步机（也称同步调相机），它们能够改变传输线路中的电感和电容的有效量。
电感和电容作用能相互抵消。当负载电流感性电抗大于容性电抗时，这种情况总是出现在大型电力系统中，对于给定的电压和电流，传送的功率小于两者相等的时候。这两个量功率之比称为功率因数。由于传输线损耗和电流成比例，如果可能，将在电路中使用电容，这样功率因数尽可能接近于1。正是这个原因，在电力传输系统中，经常使用大型电容器。
世界电力生产从1950年到2003年，最近一年的可用数据显示，每年世界电力生产和消费从小于1万亿千瓦时增长到15.9万亿千瓦时。同样，发电类型也发生了变化。在1950年，世界电力约2/3来自蒸汽源，约1/3 来自水电。2003年，热源生产65%的电能，水电却降至17%，核电占总量的16%。出于安全的考虑，在一些国家，特别是美国，核能的增长缓慢。2003年，美国电能的20%来自核电厂；在世界领先的法国，这个数字是78%。
保护
世界上大多数电能的生产来自天然气、煤炭、石油和铀等不可再生资源。煤炭、石油、天然气含有碳元素，它们的燃烧加剧了二氧化碳和其它污染物的排放。科学家们认为，二氧化碳是导致全球变暖，地球表面温度上升的主要因素。
电力用户通过节约用电，如离开房间时关闭电灯等措施消除不必要消耗，可以节省资金，有助于环境保护。其它保护措施包括购买和使用节能电器和灯泡，在费率较低的非用电高峰使用洗衣机和烘干机等电器。消费者也可以考虑环境措施，如购买当地公共部门提供的绿色能源等。绿色能源通常价格较贵，但依靠可再生和环境友好型资源，如风力轮机和地热发电厂。
工业设计原著选读 优秀的产品设计 第一个拨号电话1897年由卡罗耳Gantz 第一个拨号电话在1897年被自动电器公司引入，成立于1891年布朗强，一名勘萨斯州承担者。在1889年，相信铃声“中央交换”将转移来电给竞争对手，强发明了被拨号系统控制的自动交换机系统。这个系统在1892年第一次在拉波特完成史端乔系统中被安装。1897年，强的模型电话，然而模型扶轮拨条的位置没有类似于轮齿约170度,以及边缘拨阀瓣。电话，当然是被亚历山大格雷厄姆贝尔（1847—1922）在1876年发明的。第一个商业交换始建于1878（12个使用者），在1879年，多交换机系统由工程师勒罗伊B 菲尔曼发明,使电话取得商业成功,用户在1890年达到250000。 直到1894年，贝尔原批专利过期，贝尔电话公司在市场上有一个虚拟的垄断。他们已经成功侵权投诉反对至少600竞争者。该公司曾在1896年，刚刚在中央交易所推出了电源的“普通电池”制度。在那之前，一个人有手摇电话以提供足够的电力呼叫。一个连接可能仍然只能在给予该人的名义下提出要求达到一个电话接线员。这是强改变的原因。 强很快成为贝尔的强大竞争者。他在1901年引进了一个桌面拨号模型，这个模型在设计方面比贝尔的模型更加清晰。在1902年，他引进了一个带有磁盘拨号的墙面电话，这次与实际指孔，仍然只有170度左右在磁盘周围。到1905年，一个“长距离”手指孔已经被增加了。最后一个强的知名模型是在1907年。强的专利大概过期于1914年，之后他或他的公司再也没有听到过。直到1919年贝尔引进了拨号系统。当他们这样做，在拨号盘的周围手指孔被充分扩展了。 强发明的拨号系统直到1922年进入像纽约一样的大城市才成为主流。但是一旦作为规规范被确立，直到70年代它仍然是主要的电话技术。后按键式拨号在1963年被推出之后，强发明的最初的手指拨号系统作为“旋转的拨号系统”而知名。这是强怎样“让你的手指拨号”的。 埃姆斯椅LCW和DCW 1947 这些带有复合曲线座位，靠背和橡胶防震装置的成型胶合板椅是由查尔斯埃姆斯设计，在赫曼米勒家具公司生产的。 这个原始的概念是被查尔斯埃姆斯（1907—1978）和埃罗沙里宁（1910—1961）在1940年合作构想出来的。在1937年，埃姆斯成为克兰布鲁克学院实验设计部门的领头人，和沙里宁一起工作调查材料和家具。在这些努力下，埃姆斯发明了分成薄片和成型胶合板夹板，被称作埃姆斯夹板，在1941年收到了来自美国海军5000人的订单。查尔斯和他的妻子雷在他们威尼斯，钙的工作室及工厂和埃文斯产品公司的生产厂家一起生产了这批订单。 在1941年现代艺术博物馆，艾略特诺伊斯组织了一场比赛用以发现对现代生活富有想象力的设计师。奖项颁发给了埃姆斯和沙里宁他们的椅子和存储碎片，由包括埃德加考夫曼，大都会艺术博物馆的阿尔弗雷德，艾略特诺伊斯，马尔塞布鲁尔，弗兰克帕里什和建筑师爱德华达雷尔斯通的陪审团裁决。 这些椅子在1946年的现代艺术展览博物馆被展出，查尔斯埃姆斯设计的新的家具。当时，椅子只有三条腿，稳定性问题气馁了大规模生产。 早期的LCW（低木椅）和DWC（就餐木椅）设计有四条木腿在1946年第一次被埃文斯产品公司（埃姆斯的战时雇主）生产出来，被赫曼米勒家具公司分配。这些工具1946年被乔治纳尔逊为赫曼米勒购买，在1949年接手制造权。后来金属脚的愿景在1951年制作，包括LCW（低金属椅）和DWC（就餐金属椅）模型。配套的餐饮和咖啡桌也产生。这条线一直
机械设计 摘要：机器是由机械装置和其它组件组成的。它是一种用来转换或传递能量的装置，例如：发动机、涡轮机、车辆、起重机、印刷机、洗衣机、照相机和摄影机等。许多原则和设计方法不但适用于机器的设计，也适用于非机器的设计。术语中的“机械装置设计”的含义要比“机械设计”的含义更为广泛一些，机械装置设计包括机械设计。在分析运动及设计结构时，要把产品外型以及以后的保养也要考虑在机械设计中。在机械工程领域中，以及其它工程领域中，所有这些都需要机械设备，比如：开关、凸轮、阀门、船舶以及搅拌机等。 关键词：设计流程设计规则机械设计 设计流程 设计开始之前就要想到机器的实际性，现存的机器需要在耐用性、效率、重量、速度，或者成本上得到改善。新的机器必需具有以前机器所能执行的功能。 在设计的初始阶段，应该允许设计人员充分发挥创造性，不要受到任何约束。即使产生了许多不切实际的想法，也会在设计的早期，即在绘制图纸之前被改正掉。只有这样，才不致于阻断创新的思路。通常,还要提出几套设计方案，然后加以比较。很有可能在这个计划最后决定中,使用了某些不在计划之内的一些设想。 一般的当外型特点和组件部分的尺寸特点分析得透彻时，就可以全面的设计和分析。接着还要客观的分析机器性能的优越性，以及它的安全、重量、耐用性，并且竞争力的成本也要考虑在分析结果之内。每一个至关重要的部分要优化它的比例和尺寸，同时也要保持与其它组成部分相协调。 也要选择原材料和处理原材料的方法。通过力学原理来分析和实现这些重要的特性，如那些静态反应的能量和摩擦力的最佳利用，像动力惯性、加速动力和能量；包括弹性材料的强度、应力和刚度等材料的物理特性，以及流体润滑和驱动器的流体力学。设计的过程是重复和合作的过程，无论是正式或非正式的进行，对设计者来说每个阶段都很重要。 最后，以图样为设计的标准，并建立将来的模型。如果它的测试是符合事先要
附录1 RURAL FINANCE: MAINSTREAMING INFORMAL FINANCIAL INSTITUTIONS By Hans Dieter Seibel Abstract Informal financial institutions (IFIs), among them the ubiquitous rotating savings and credit associations, are of ancient origin. Owned and self-managed by local people, poor and non-poor, they are self-help organizations which mobilize their own resources, cover their costs and finance their growth from their profits. With the expansion of the money economy, they have spread into new areas and grown in numbers, size and diversity; but ultimately, most have remained restricted in size, outreach and duration. Are they best left alone, or should they be helped to upgrade their operations and be integrated into the wider financial market? Under conducive policy conditions, some have spontaneously taken the opportunity of evolving into semiformal or formal microfinance institutions (MFIs). This has usually yielded great benefits in terms of financial deepening, sustainability and outreach. Donors may build on these indigenous foundations and provide support for various options of institutional development, among them: incentives-driven mainstreaming through networking; encouraging the establishment of new IFIs in areas devoid of financial services; linking IFIs/MFIs to banks; strengthening Non-Governmental Organizations (NGOs) as promoters of good practices; and, in a nonrepressive policy environment, promoting appropriate legal forms, prudential regulation and delegated supervision. Key words: Microfinance, microcredit, microsavings。 1. informal finance, self-help groups In March 1967, on one of my first field trips in Liberia, I had the opportunity to observe a group of a dozen Mano peasants cutting trees in a field belonging to one of them. Before they started their work, they placed hoe-shaped masks in a small circle, chanted words and turned into animals. One turned into a lion, another one into a bush hog, and so on, and they continued to imitate those animals throughout the whole day, as they worked hard on their land. I realized I was onto something serious, and at the end of the day, when they had put the masks into a bag and changed back into humans,
吉林化工学院理学院 毕业论文外文翻译English Title（Times New Roman ，三号） 学生学号：08810219 学生姓名：袁庚文 专业班级：信息与计算科学0802 指导教师：赵瑛 职称副教授 起止日期：2012.2.27～2012.3.14 吉林化工学院 Jilin Institute of Chemical Technology
1 外文翻译的基本内容 应选择与本课题密切相关的外文文献（学术期刊网上的），译成中文，与原文装订在一起并独立成册。在毕业答辩前，同论文一起上交。译文字数不应少于3000个汉字。 2 书写规范 2.1 外文翻译的正文格式 正文版心设置为：上边距：3.5厘米，下边距：2.5厘米，左边距：3.5厘米，右边距：2厘米，页眉：2.5厘米，页脚：2厘米。 中文部分正文选用模板中的样式所定义的“正文”，每段落首行缩进2字；或者手动设置成每段落首行缩进2字，字体：宋体，字号：小四，行距：多倍行距1.3，间距：前段、后段均为0行。 这部分工作模板中已经自动设置为缺省值。 2.2标题格式 特别注意：各级标题的具体形式可参照外文原文确定。 1．第一级标题（如：第1章绪论）选用模板中的样式所定义的“标题1”，居左；或者手动设置成字体：黑体，居左，字号：三号，1.5倍行距，段后11磅，段前为11磅。 2．第二级标题（如：1.2 摘要与关键词）选用模板中的样式所定义的“标题2”，居左；或者手动设置成字体：黑体，居左，字号：四号，1.5倍行距，段后为0，段前0.5行。 3．第三级标题（如：1.2.1 摘要）选用模板中的样式所定义的“标题3”，居左；或者手动设置成字体：黑体，居左，字号：小四，1.5倍行距，段后为0，段前0.5行。 标题和后面文字之间空一格（半角）。 3 图表及公式等的格式说明 图表、公式、参考文献等的格式详见《吉林化工学院本科学生毕业设计说明书（论文）撰写规范及标准模版》中相关的说明。
Interaction design Moggridge Bill Interaction design，Page 1-15 USA Art Press, 2008 Interaction design (IxD) is the study of devices with which a user can interact, in particular computer users. The practice typically centers on "embedding information technology into the ambient social complexities of the physical world."[1] It can also apply to other types of non-electronic products and services, and even organizations. Interaction design defines the behavior (the "interaction") of an artifact or system in response to its users. Malcolm McCullough has written, "As a consequence of pervasive computing, interaction design is poised to become one of the main liberal arts of the twenty-first century." Certain basic principles of cognitive psychology provide grounding for interaction design. These include mental models, mapping, interface metaphors, and affordances. Many of these are laid out in Donald Norman's influential book The Psychology of Everyday Things. As technologies are often overly complex for their intended target audience, interaction design aims to minimize the learning curve and to increase accuracy and efficiency of a task without diminishing usefulness. The objective is to reduce frustration and increase user productivity and satisfaction. Interaction design attempts to improve the usability and experience of the product, by first researching and understanding certain users' needs and then designing to meet and exceed them. (Figuring out who needs to use it, and how those people would like to use it.) Only by involving users who will use a product or system on a regular basis will designers be able to properly tailor and maximize usability. Involving real users, designers gain the ability to better understand user goals and experiences. (see also: User-centered design) There are also positive side effects which include enhanced system capability awareness and user ownership. It is important that the user be aware of system capabilities from an early stage so that expectations regarding functionality are both realistic and properly understood. Also, users who have been active participants in a product's development are more likely to feel a sense of ownership, thus increasing overall satisfa. Instructional design is a goal-oriented, user-centric approach to creating training and education software or written materials. Interaction design and instructional design both rely on cognitive psychology theories to focus on how users will interact with software. They both take an in-depth approach to analyzing the user's needs and goals. A needs analysis is often performed in both disciplines. Both, approach the design from the user's perspective. Both, involve gathering feedback from users, and making revisions until the product or service has been found to be effective. (Summative / formative evaluations) In many ways, instructional
运作整合 供应链协作的首要问题是提高运作整合的程度。供应链协作课达到的好处，直接关系到捕捉效率之间的职能的企业，以及全国的企业，构成了国内或国际供应链。本章重点阐述的挑战，一体化管理，由研究为什么一体化创造价值，并通过详列的挑战，双方的企业集成和供应链整合。必不可少的供应链流程是确定的。注意的是，然后向信息技术提供，以方便集成化供应链规划。本章最后审查了定价。在最后的分析，定价的做法和政府是至关重要的供应链的连续性。 为什么整合创造价值 基本的优点与挑战的综合管理介绍了在第1章。进一步解释整合管理的重要性，有用的指出客户都至少有三个角度的价值。 传统的角度来看，价值是经济价值。第二个价值的角度来看，是市场价值。 实现双方经济和市场价值是很重要的客户。然而，越来越多的企业认识到商业上的成功也取决于第三个角度来看，价值，被称为关联性。 物流一体化目标 为实现物流一体化的供应链背景下，6个业务目标必须同时取得：（ 1 ）响应，（ 2 ）差额减少，（ 3 ）库存减少，（ 4 ）托运巩固，（ 5 ）质量，（ 6 ）生命周期支持。的相对重要性，每个直接关系到公司的物流战略。 响应 一公司的工作能力，以满足客户的要求，及时被称为反应。作为一再指出，信息技术是促进反应为基础的战略，允许业务的承诺被推迟到最后可能时间，其次是加速投放。实施对应策略服务，以减少库存承诺或部署在预期客户的需求。响应服务转向业务重点从预测未来的需求，以容纳顾客对快速订单到出货的基础上。理想的情况是，在一个负责任的系统中，库存是没有部署，直到客户承诺。支持这样的承诺，公司必须有物流的属性，库存的可用性和及时交付，一旦客户订单收到。 差异减少 所有经营领域的物流系统很容易受到差额。方差结果从未能履行任何预期的层面后勤业务不如预期。举例来说，毫不拖延地在客户订单处理，意想不到的干扰，以便选择，抵港货物损坏，在客户的位置，和/或未能提供在适当的位置上的时间，所有创造无计划的差异，在订单到交货周期。一个共同的解决办法，以保障对不利的差异是使用库存安全库存，以缓冲行动。这亦是共同使用的首选运输，以克服意想不到的差异延误交货计划。这种做法，鉴于其相关的成本高，可以尽量减少使用资讯科技，以维持积极的物流控制。向程度的差异是最小化，物流的生产力将提高。因此，差异减少，消除系统中断，是一个基本的目标，综合物流管理。 库存减少 要达到的目标，库存减少，一个综合物流系统必须控制资产的承诺，并把速度。资产的承诺，是财政的价值部署清单。把速度，反映了利率，这是充实库存随着时间的推移。高转率，再加上预期的库存供货，平均资产用于库存正在迅速而有效利用，这就是整体资产承诺支持一个综合运作减至最低。 库存能够而且确实方便可取的好处这是很重要的要请记住。库存是至关重要的实现规模经济，在制造业和采购。目的是要减少和管理存货，以尽可能最低的水平，同时实现整体供应链绩效的目标。
Injection Molding The basic concept of injection molding revolves around the ability of a thermoplastic material to be softened by heat and to harden when cooled .In most operations ,granular material (the plastic resin) is fed into one end of the cylinder (usually through a feeding device known as a hopper ),heated, and softened(plasticized or plasticized),forced out the other end of the cylinder, while it is still in the form of a melt, through a nozzle into a relatively cool mold held closed under pressure.Here,the melt cools and hardens until fully set-up. The mold is then opened, the piece ejected, and the sequence repeated. Thus, the significant elements of an injection molding machine become: 1) the way in which the melt is plasticized (softened) and forced into the mold (called the injection unit); 2) the system for opening the mold and closing it under pressure (called the clamping unit);3) the type of mold used;4) the machine controls. The part of an injection-molding machine, which converts a plastic material from a sold phase to homogeneous seni-liguid phase by raising its temperature .This unit maintains the material at a present temperature and force it through the injection unit nozzle into a mold .The plunger is a combination of the injection and plasticizing device in which a heating chamber is mounted between the plunger and mold. This chamber heats the plastic material by conduction .The plunger, on each stroke; pushes unbelted plastic material into the chamber, which in turn forces plastic melt at the front of the chamber out through the nozzle The part of an injection molding machine in which the mold is mounted, and which provides the motion and force to open and close the mold and to hold the mold close with force during injection .This unit can also provide other features necessary for the effective functioning of the molding operation .Moving
软件专业毕业论文外文文献中英文翻译 Object landscapes and lifetimes Tech nically, OOP is just about abstract data typing, in herita nee, and polymorphism, but other issues can be at least as importa nt. The rema in der of this sect ion will cover these issues. One of the most importa nt factors is the way objects are created and destroyed. Where is the data for an object and how is the lifetime of the object con trolled? There are differe nt philosophies at work here. C++ takes the approach that con trol of efficie ncy is the most importa nt issue, so it gives the programmer a choice. For maximum run-time speed, the storage and lifetime can be determined while the program is being written, by placing the objects on the stack (these are sometimes called automatic or scoped variables) or in the static storage area. This places a priority on the speed of storage allocatio n and release, and con trol of these can be very valuable in some situati ons. However, you sacrifice flexibility because you must know the exact qua ntity, lifetime, and type of objects while you're writing the program. If you are trying to solve a more general problem such as computer-aided desig n, warehouse man ageme nt, or air-traffic con trol, this is too restrictive. The sec ond approach is to create objects dyn amically in a pool of memory called the heap. In this approach, you don't know un til run-time how many objects you n eed, what their lifetime is, or what their exact type is. Those are determined at the spur of the moment while the program is runnin g. If you n eed a new object, you simply make it on the heap at the point that you n eed it. Because the storage is man aged dyn amically, at run-time, the amount of time required to allocate storage on the heap is sig ni fica ntly Ion ger tha n the time to create storage on the stack. (Creat ing storage on the stack is ofte n a si ngle assembly in structio n to move the stack poin ter dow n, and ano ther to move it back up.) The dyn amic approach makes the gen erally logical assumpti on that objects tend to be complicated, so the extra overhead of finding storage and releas ing that storage will not have an importa nt impact on the creati on of an object .In additi on, the greater flexibility is esse ntial to solve the gen eral program ming problem. Java uses the sec ond approach, exclusive". Every time you want to create an object, you use the new keyword to build a dyn amic in sta nee of that object. There's ano ther issue, however, and that's the lifetime of an object. With Ian guages that allow objects to be created on the stack, the compiler determines how long the object lasts and can automatically destroy it. However, if you create it on the heap the compiler has no kno wledge of its lifetime. In a Ianguage like C++, you must determine programmatically when to destroy the
(文档含英文原文和中文翻译) 中英文翻译原文：
DESIGN and ENVIRONMENT Product design is the principal part and kernel of industrial design. Product design gives uses pleasure. A good design can bring hope and create new lifestyle to human. In spscificity,products are only outcomes of factory such as mechanical and electrical products,costume and so on.In generality,anything,whatever it is tangibile or intangible,that can be provided for a market,can be weighed with value by customers, and can satisfy a need or desire,can be entiled as products. Innovative design has come into human life. It makes product looking brand-new and brings new aesthetic feeling and attraction that are different from traditional products. Enterprose tend to renovate idea of product design because of change of consumer's lifestyle , emphasis on individuation and self-expression,market competition and requirement of individuation of product. Product design includes factors of society ,economy, techology and leterae humaniores. Tasks of product design includes styling, color, face processing and selection of material and optimization of human-machine interface. Design is a kind of thinking of lifestyle.Product and design conception can guide human lifestyle . In reverse , lifestyle also manipulates orientation and development of product from thinking layer.
农村金融小额信贷中英文对照外文翻译文献(文档含英文原文和中文翻译) RURAL FINANCE: MAINSTREAMING INFORMAL FINANCIAL INSTITUTIONS By Hans Dieter Seibel Abstract Informal financial institutions (IFIs), among them the ubiquitous rotating savings and credit associations, are of ancient origin. Owned and self-managed by local people, poor and non-poor, they are self-help organizations which mobilize their own resources, cover their costs and finance their growth from their profits. With the expansion of the money economy, they have spread into new areas and grown in numbers, size and diversity; but ultimately, most have remained restricted in size, outreach and duration. Are they best left alone, or should they be helped to upgrade
The mold designing and manufacturing The mold is the manufacturing industry important craft foundation, in our country, the mold manufacture belongs to the special purpose equipment manufacturing industry. China although very already starts to make the mold and the use mold, but long-term has not formed the industry. Straight stabs 0 centuries 80's later periods, the Chinese mold industry only then drives into the development speedway. Recent years, not only the state-owned mold enterprise had the very big development, the three investments enterprise, the villages and towns (individual) the mold enterprise's development also rapid quietly. Although the Chinese mold industrial development rapid, but compares with the demand, obviously falls short of demand, its main gap concentrates precisely to, large-scale, is complex, the long life mold domain. As a result of in aspect and so on mold precision, life, manufacture cycle and productivity, China and the international average horizontal and the developed country still had a bigger disparity, therefore, needed massively to import the mold every year . The Chinese mold industry must continue to sharpen the productivity, from now on will have emphatically to the profession internal structure adjustment and the state-of-art enhancement. The structure adjustment aspect, mainly is the enterprise structure to the specialized adjustment, the product structure to center the upscale mold development, to the import and export structure improvement, center the upscale automobile cover mold forming analysis and the structure improvement, the multi-purpose compound mold and the compound processing and the laser technology in the mold design manufacture application, the high-speed cutting, the super finishing and polished the technology, the information direction develops . The recent years, the mold profession structure adjustment and the organizational reform step enlarges, mainly displayed in, large-scale, precise, was complex, the long life, center the upscale mold and the mold standard letter development speed is higher than the common mold product; The plastic mold and the compression casting mold proportion increases; Specialized mold factory quantity and its productivity increase;