西安科技大学毕业设计(外文翻译)
院（系、部)：专业及班级：电气与控制工程学院微电子学0701班
姓名：刘红卫
译文：
大屏幕显示系统的研究
LED的发展
随着计算机技术的高速发展，LED屏幕显示系统作为继电视、广播、报纸、杂志之后的“第五大媒体”正快速步入社会生活的各个方面。它集微电子技术、计算机技术、信息处理技术于一体，可以将信息通过文字、图案、动画及视频
四种形式显示出来。与电视墙、磁翻板等媒体相比，LED大屏幕显示系统具有图案美观、色彩亮丽；图案、色彩变化丰富、快速；低功耗、长寿命、使用成本低、工作稳定可靠等特点。它显示的图文视角大、视距远，因而已广泛应用于大型广场、商业广告、体育场馆、信息传播、新闻发布、证券交易；它还应用于工业控制和工业调动系统，便于把各种参数、报警点、工艺流程显示得更加清晰完美，可以满足不同环境的需要。LED显示屏是一种利用计算机和复杂数字信号处理的电子广告宣传屏。它的屏体部分由微处理器（主要是单片机）和驱动电路控制运行，显示的图像或文字由计算机编辑软件编辑获得。由于LED显示屏这种新一代信息显示设备具有显示图案稳定、功耗低、寿命长等特点，而且它综合了各种信息显示设备的长处，并且克服了自身的不足，特别是由于一幅显示屏可以显示不同的内容，显示方式丰富。所以在公共场合，它具有强烈的广告宣传和信息传递效果，日趋在固体显示中占主导地位。LED显示屏的发展前景极为广阔，目前正朝着更高亮度、更高耐气候性、更高的发光密度、更高的发光均匀性、可靠性、全色化方向发展。由不同材料的半导体组成能发出不同色彩的LED晶点。目前应用最广的是红色、绿色、黄色LED。而蓝色和纯绿色LED的开发已经达到了实用阶段。
LED显示屏的分类
LED显示屏是多种技术综合应用的产品，涉及光电子学、半导体器件、数字电子电路、大规模集成电路、单片机及微机等各个方面，既有硬件又有软件。LED显示屏是作为广播、电视、报纸、杂志之后的又一新传播媒体。目前LED显示屏根据使用场所不同，可以分为室外屏和室内屏两种，其主要区别是发光管的发光亮度不同。而根据所显示的内容不同也可以分为图像屏和文字屏两种，
图像屏可以显示图像以及多媒体，而文字屏则主要显示文字或简单的固定图像。显示图像的多媒体室外屏是投资巨大(高达数百万)的大型高档设备，主要应用
在大型公共场所、形象工程和一些重要场所。LED显示屏的应用涉及到社会经
济的许多领域，已经遍及交通、证券、电信、广告、宣传等各个方面。
L ED显示屏的发展趋势
目前LED显示屏的显示向更高亮度、更高耐气候性、更高的发光均匀性、更高的可靠性、全色化、多媒体方向发展，系统的运行、操作与维护也向集成化、网络化、智能化方向发展。二十一世纪的显示技术将是平板显示的时代，LED显示屏作为平板显示的主导产品之一将有更大的发展。
1．高亮度、全彩化蓝色及绿色超高亮度LED产品出现以来，成本逐年快速降低，使LED全彩色显示屏产品成本下降，推广速度加快。同时，随着控制技术的发展和LED显示屏体稳定性的提高，全彩色LED显示屏的亮度、色彩、白平衡均达到比较理想的效果，完全可以满足户外全天候的环境条件要求，而且图像更清晰、更细腻、更亮丽。
2．标准化、规范化材料、技术的成熟及市场价格基本均衡之后，LED显示
屏的标准化和规范化将成为LED显示屏发展的一个趋势。近几年业内的发展中，几番价格回落调整达到基本均衡后，产品质量、系统的可靠性等将成为主要的
竞争因素，这就对LED显示屏的标准化和规范化有了较高的要求。行业规范和标准体系的形成，IS09000系列标准的应用，使LED显示屏行业的发展趋于有序。
3．产品结构多样化随着信息化社会的形成，信息领域愈加广泛，LED显示
屏的应用前景更为广阔。预计大型或超大型LED显示屏为主流产品的局面将会
发生改变，适合于服务行业特点和专业性要求的小型LED显示屏会有较大提高，面向信息服务领域的LED显示屏产品门类和品种体系将更加丰富，部分潜在市
场需求和应用领域将会有所突破，如公共交通、停车场、餐饮、医院等综合服
务方面的信息显示屏需求量将有更大的提高。
涉及思路及工作原理
本系统根据经典的电路设计思路，采用自下而上的设计方法，从显示板到驱动板，再到控制板，进行硬件编程，调试成功后接电源板，最后完成数据传输板与PC机相连接，进行PC软件编程，完成显示数据的生成、提取、处理、传输以及显示效果的实时控制。每个模块采用8个LED点阵以行扫描形式点亮各行的红、绿、红绿灯，显示文字和图像。LED点阵的驱动、译码、锁存等由控制板的数字电路负责。其数据由单片机从存储器中读取，同时单片机采用中断方式，通过RS-232数据线与PC机进行双向通信，从PC机获取命令或数据，
并按命令执行动作或者存储数据。而PC机不但与多个单片机进行多机串口通信，还要负责文字录入和排版，生成点阵数据或者命令字，实现人机交互功能。工作原理
本文设计的大型LED显示屏由双基色点阵LED组合而成，采用逐行扫描的显
示方式显示红、绿、黄三种颜色的任意点阵信息。显示模块采用逐行扫描显示的方式，其控制系统以单片机AT89C52为核心，采用62256存储器作为数据存储器，利用锁存器74HC377和8组线驱动器2083A驱动8*8的LED显示模块，同时开放串口中断与上位PC机进行多机通信。通过对单片机编程实现显示屏的多种动画
模式显示：向左滚屏，向右滚屏，向上滚屏，向下滚屏，向左上滚屏，向右上滚屏，向左拉幕，向右拉幕，向上拉幕，向下拉幕，向右移，从左向右、依次点亮，从中间到两边、依次点亮。动画速度可调：分为100档，最低为1 速，最高为
100速。图案颜色多样：背景无色、文字红/绿/黄色，背景红色、文字无/黄/绿色，背景绿色、文字无/黄/红色，背景黄色，文字无/红/绿色。另外，还增加了几十种霓虹灯效果动画。PC机上的显示控制软件可以实现汉字录入、字体选择、字号更改等功能，并且在进行数据处理后，可以在左侧模拟演示整体效果，同时“所见即所得”的显示在下方预览区域。另外，该控制软件还具有文本选定、鼠标定位、坐标追踪、时间日期等附加功能。PC机通过 RS-232接口实现与显示部
分的单片机的通信，利用单片机串口中断实时接收和发送数据信息。在系统设计中还兼顾了单片机的抗干扰能力，有效地提高了系统运行的可靠性。
发光二级管特性
发光二极管(light emitting diode,LED)，是一种把电能变成光能的特种
器件，当电流达到门限电流时，发光二极管导通，随着电流的通过，产生可见光。发光二极管的结构主要由PN结芯片、电极和光学系统构成。当在PN结上加以正向电压之后，P区的空穴注入至N区，N区的电子注入至P区，相互注入的电子
与空穴相遇后即产生复合，这些少数载流子在PN结的注入和复合中产生辐射而
发光。它是自发辐射发光，不需要较高的注入电流产生粒子数反转分布，也不需要光学谐振腔，发射的是非相干光。描述LED的特性有许多参数，这些参数之间的关系呈现非线性。因此，用特性曲线来描述这些关系，在工程应用中更具有使用价值。
LED器件的驱动
从LED器件的发光机理可以知道，当向LED器件施加正向电压时，流过器件的正向电流使其发光。因此LED的驱动就是要使它的PN结处于正向偏置，同时为了控制它的发光强度，还要解决正向电流的调节问题。具体的驱动方式有直流驱动、恒流驱动、脉冲驱动和扫描驱动等，本系统中LED器件的驱动为扫描驱动。
1．直流驱动。直流驱动是最简单的驱动方法。LED的工作点由电源电压VCC，串联电阻R和LED器件的伏安特性共同决定。这种驱动方式适合于LED器件较少，发光强度恒定的情况。例如公交车上使用的用来固定显示“XX路”字样的显示屏。
2．恒流驱动。由于LED器件的正向特性较陡，加上器件的分散性，使得在同样电源电压和同样限流电阻的情况下，各器件的正向电流并不相同，从而引起发光强度的差异。若对LED器件进行恒流驱动，只要恒流值相同，发光强度就比较接近。晶体管的输出特性具有恒流特性，所以可以用晶体管驱动LED。
3．脉冲驱动。利用人眼的视觉惰性，采用向LED器件重复通断电的方式使之点燃，就是脉冲驱动方式。脉冲驱动主要有两个方面的应用：扫描驱动和占空比驱动。扫描驱动的主要目的是节约驱动器，简化电路。采用这种方式时应该注意两个问题:确定脉冲电流幅值和选择重复频率。首先，要想获得与直流驱动方式相当的发光强度，脉冲驱动电流的平均值就应该与直流驱动的电流值相同。
4．扫描驱动。扫描驱动通过数字逻辑电路，使若干LED器件轮流导通，用以节省控制驱动电路。LED显示屏将发光灯按行按列布置，驱动时也按行按列驱动。在扫描驱动方式下可以按行扫描，按列控制；也可以按列扫描，按行控制。所谓“扫描”的含义，就是指一行一行地循环接通整行的LED器件，而不管这一行的哪一列的LED器件是否应该点亮，具体某一列的LED器件是否应该点亮，则由所谓的列控制电路来负责。
中英文对照外文翻译 (文档含英文原文和中文翻译) Create and comprehensive technology in the structure global design of the building The 21st century will be the era that many kinds of disciplines technology coexists , it will form the enormous motive force of promoting the development of building , the building is more and more important too in global design, the architect must seize the opportunity , give full play to the architect's leading role, preside over every building engineering design well. Building there is the global design concept not new of architectural design,characteristic of it for in an all-round way each element not correlated with building- there aren't external environment condition, building , technical equipment,etc. work in coordination with, and create the premium building with the comprehensive new technology to combine together. The premium building is created, must consider sustainable development , namely future requirement , in other words, how save natural resources as much as possible, how about protect the environment that the mankind depends on for existence, how construct through high-quality between architectural design and building, in order to reduce building equipment use quantity and
毕业设计（论文）外文文献翻译 文献、资料中文题目：软件开发概念和设计方法文献、资料英文题目： 文献、资料来源： 文献、资料发表（出版）日期： 院（部）： 专业： 班级： 姓名： 学号： 指导教师： 翻译日期： 2017.02.14
外文资料原文 Software Development Concepts and Design Methodologies During the 1960s, ma inframes and higher level programming languages were applied to man y problems including human resource s yste ms,reservation s yste ms, and manufacturing s yste ms. Computers and software were seen as the cure all for man y bu siness issues were some times applied blindly. S yste ms sometimes failed to solve the problem for which the y were designed for man y reasons including: ?Inability to sufficiently understand complex problems ?Not sufficiently taking into account end-u ser needs, the organizational environ ment, and performance tradeoffs ?Inability to accurately estimate development time and operational costs ?Lack of framework for consistent and regular customer communications At this time, the concept of structured programming, top-down design, stepwise refinement，and modularity e merged. Structured programming is still the most dominant approach to software engineering and is still evo lving. These failures led to the concept of "software engineering" based upon the idea that an engineering-like discipl ine could be applied to software design and develop ment. Software design is a process where the software designer applies techniques and principles to produce a conceptual model that de scribes and defines a solution to a problem. In the beginning, this des ign process has not been well structured and the model does not alwa ys accurately represent the problem of software development. However,design methodologies have been evolving to accommo date changes in technolog y coupled with our increased understanding of development processes. Whereas early desig n methods addressed specific aspects of the
DC Switching Power Supply Protection Technology Abstract: The DC switching power supply protection system, protection system design principles and machine protection measures, an analysis of switching power supply in the range of protected characteristics and its design methodology,introduced a number of practical protection circuit. Keywords: switching power supply protection circuit system design 1、Introduction DC switching regulator used in the price of more expensive high-power switching devices, the control circuit is also more complex, In addition, the load switching regulators are generally used a large number of highly integrated electronic systems installed devices. Transistors and integrated device tolerance electricity, less heat shocks. Switching Regulators therefore should take into account the protection of voltage regulators and load their own safety. Many different types of circuit protection, polarity protection, introduced here, the program protection, over-current protection, over-voltage protection, under-voltage protection and over-temperature protection circuit. Usually chosen to be some combination of protection, constitutes a complete protection system. 2、polarity protection DC switching regulator input are generally not regulated DC power supply. Operating errors or accidents as a result of the situation will take its wrong polarity, switching power supply will be damaged. Polarity protection purposes, is to make the switching regulator only when the correct polarity is not connected to DC power supply regulator to work at. Connecting a single device can achieve power polarity protection. Since the diode D to flow through switching regulator input total current, this circuit applied in a low-power switching regulator more suitable. Power in the larger occasion, while the polarity protection circuit as a procedure to protect a link, save the power required for polarity protection diodes, power consumption will be reduced. In order to easy to operate, make it easier to identify the correct polarity or not, collect the next light. 3、procedures to protect Switching power supply circuit is rather complicated, basically can be divided into low-power and high-power part of the control part of the switch. Switch is a high-power
The future of the tall building and structure of buildings Zoning effects on the density of tall buildings and solar design may raise ethical challenge. A combined project of old and new buildings may bring back human scale to our cities. Owners and conceptual designers will be challenged in the 1980s to produce economically sound, people-oriented buildings. In 1980 the Level House, designed by Skidmore, Owings and Merril1 (SOM) received the 25-year award from the American Institute of Architects “in recogn ition of architectural design of enduring significance”. This award is given once a year for a building between 25and 35 years old .Lewis Mumford described the Lever House as “the first office building in which modern materials, modern construction, modern functions have been combined with a modern plan”. At the time, this daring concept could only be achieved by visionary men like Gordon Bunshaft, the designer , and Charles Luckman , the owner and then-president of Lever Brothers . The project also include d a few “first” : (1) it was the first sealed glass tower ever built ; (2) it was the first office building designed by SOM ;and (3) it was the first office building on Park Avenue to omit retail space on the first floor. Today, after hundreds of look-alike and variations on the grid design, we have reached what may be the epitome of tall building design: the nondescript building. Except for a few recently completed buildings that seem to be people-oriented in their lower floors, most tall buildings seem to be arepletion of the dull, graph-paper-like monoliths in many of our cities. Can this be the end of the design-line for tall buildings? Probably cannot. There are definite signs that are most encouraging. Architects and owners have recently begun to discuss the design problem publicly. Perhaps we are at the threshold of a new era. The 1980s may bring forth some new visionaries like Bunshaft and Luckman. If so, what kinds of restrictions or challenges do they face? Zoning Indications are strong that cities may restrict the density of tall buildings, that is, reduce the number of tall buildings per square mile. In 1980 the term
外文翻译 专业机械设计制造及其自动化学生姓名刘链柱 班级机制111 学号1110101102 指导教师葛友华
外文资料名称： Design and performance evaluation of vacuum cleaners using cyclone technology 外文资料出处：Korean J. Chem. Eng., 23(6), (用外文写) 925-930 (2006) 附件： 1.外文资料翻译译文 2.外文原文
应用旋风技术真空吸尘器的设计和性能介绍 吉尔泰金，洪城铱昌，宰瑾李， 刘链柱译 摘要：旋风型分离器技术用于真空吸尘器 - 轴向进流旋风和切向进气道流旋风有效地收集粉尘和降低压力降已被实验研究。优化设计等因素作为集尘效率，压降，并切成尺寸被粒度对应于分级收集的50％的效率进行了研究。颗粒切成大小降低入口面积，体直径，减小涡取景器直径的旋风。切向入口的双流量气旋具有良好的性能考虑的350毫米汞柱的低压降和为1.5μm的质量中位直径在1米3的流量的截止尺寸。一使用切向入口的双流量旋风吸尘器示出了势是一种有效的方法，用于收集在家庭中产生的粉尘。 摘要及关键词：吸尘器; 粉尘; 旋风分离器 引言 我们这个时代的很大一部分都花在了房子，工作场所，或其他建筑，因此，室内空间应该是既舒适情绪和卫生。但室内空气中含有超过室外空气因气密性的二次污染物，毒物，食品气味。这是通过使用产生在建筑中的新材料和设备。真空吸尘器为代表的家电去除有害物质从地板到地毯所用的商用真空吸尘器房子由纸过滤，预过滤器和排气过滤器通过洁净的空气排放到大气中。虽然真空吸尘器是方便在使用中，吸入压力下降说唱空转成比例地清洗的时间，以及纸过滤器也应定期更换，由于压力下降，气味和细菌通过纸过滤器内的残留粉尘。 图1示出了大气气溶胶的粒度分布通常是双峰形，在粗颗粒（>2.0微米）模式为主要的外部来源，如风吹尘，海盐喷雾，火山，从工厂直接排放和车辆废气排放，以及那些在细颗粒模式包括燃烧或光化学反应。表1显示模式，典型的大气航空的直径和质量浓度溶胶被许多研究者测量。精细模式在0.18?0.36 在5.7到25微米尺寸范围微米尺寸范围。质量浓度为2?205微克，可直接在大气气溶胶和 3.85至36.3μg/m3柴油气溶胶。
Measurement of the Source Impedance of Conducted Emission Using Mode Separable LISN: Conducted Emission of a Switching Power Supply JUNICHI MIY ASHITA,1 MASAYUKI MITSUZAW A,1 TOSHIYUKI KARUBE,1 KIYOHITO Y AMASAW A,2 and TOSHIRO SA TO2 1Precision Technology Research Institute of Nagano Prefecture, Japan 2Shinshu University, Japan SUMMARY In the procedure for reducing conducted emissions, it is helpful to know the noise source impedance. This paper presents a method of measuring noise source complex impedances of common and differential mode separately. We propose a line impedance stabilization network (LISN) to measure common and differential mode noise separately without changing LISN impedances of each mode. With this LISN, conducted emissions of each mode are measured inserting appropriate impedances at the equipment under test (EUT) terminal of the LISN. Noise source complex impedances of switching power supply are well calculated from measured results. ? 2002 Scripta Technica, Electr Eng Jpn, 139(2): 72 78, 2002; DOI 10.1002/eej.1154 Key words:Conducted emission; noise terminal voltage; noise source impedance; line impedance stabiliza-tion network (LISN); EMI. 1. Introduction Switching power supplies are employed widely in various devices. High-speed on/off operation is accompa-nied by harmonic noise that may cause electromagnetic interference (EMI) with communication devices and other equipment. To prevent the interference, methods of meas-urement and limit values have been set for conducted noise (~30 MHz) and radiated noise (30 to 1000 MHz). Much time and effort are required to contain the noise within the limit values; hence, the efficiency of noise removal tech-niques is an urgent social problem. Understanding of the mechanism behind noise generation and propagation is necessary in order to develop efficient measures. In particu-lar, the propagation of conducted noise must be investi-gated. Modeling and analysis of equivalent circuits have been carried out in order to investigate conducted noise caused by switching [1, 2]. However, the stray capacitance and other circuit parameters of each device must be known in order to develop an equivalent circuit, which is not practicable in the field of noise removal. On the other hand, noise filters and other noise-removal devices do not actually provide the expected effect [3, 4], which is explained by the difference between the static characteristics measured at an impedance of 50 ?, and the actual impedance. Thus, it is necessary to know the noise source impedance in order to analyze the conducted noise. Regulations on the measurement of noise terminal voltage [5] suggest using LISN; in particular, the vector sum (absolute voltage) of two propagation modes, namely, common mode and differential mode, is measured in terms of the frequency spectrum. Such a measurement, however, does not provide phase data, and propagation modes cannot be separated; therefore, the noise source impedance cannot be derived easily. There are publications dealing with the calculation of the noise source impedance; for example, common mode is only considered as the principal mode, and the absolute value of the noise source impedance for the common mode is found from the ground wire current and ungrounded voltage [6], or mode-separated measure-ment is performed by discrimination between grounded and ungrounded devices [7]. However, measurement of the ground wire current is impossible in the case of domestic single-phase two-line devices. The complex impedance can be found using an impedance analyzer in the nonoperating state, but its value may be different for the operating state. Thus, there is no simple and accurate method of measuring source noise impedance as a complex impedance. ? 2002 Scripta Technica Electrical Engineering in Japan, V ol. 139, No. 2, 2002 Translated from Denki Gakkai Ronbunshi, V ol. 120-D, No. 11, November 2000, pp. 1376 1381
专业资料 学院： 专业：土木工程 姓名： 学号： 外文出处：Structural Systems to resist (用外文写) Lateral loads 附件：1.外文资料翻译译文；2.外文原文。
附件1：外文资料翻译译文 抗侧向荷载的结构体系 常用的结构体系 若已测出荷载量达数千万磅重，那么在高层建筑设计中就没有多少可以进行极其复杂的构思余地了。确实，较好的高层建筑普遍具有构思简单、表现明晰的特点。 这并不是说没有进行宏观构思的余地。实际上，正是因为有了这种宏观的构思，新奇的高层建筑体系才得以发展，可能更重要的是：几年以前才出现的一些新概念在今天的技术中已经变得平常了。 如果忽略一些与建筑材料密切相关的概念不谈，高层建筑里最为常用的结构体系便可分为如下几类： 1.抗弯矩框架。 2.支撑框架，包括偏心支撑框架。 3.剪力墙，包括钢板剪力墙。 4.筒中框架。 5.筒中筒结构。 6.核心交互结构。 7. 框格体系或束筒体系。 特别是由于最近趋向于更复杂的建筑形式，同时也需要增加刚度以抵抗几力和地震力，大多数高层建筑都具有由框架、支撑构架、剪力墙和相关体系相结合而构成的体系。而且，就较高的建筑物而言，大多数都是由交互式构件组成三维陈列。 将这些构件结合起来的方法正是高层建筑设计方法的本质。其结合方式需要在考虑环境、功能和费用后再发展，以便提供促使建筑发展达到新高度的有效结构。这并
不是说富于想象力的结构设计就能够创造出伟大建筑。正相反，有许多例优美的建筑仅得到结构工程师适当的支持就被创造出来了，然而，如果没有天赋甚厚的建筑师的创造力的指导，那么，得以发展的就只能是好的结构，并非是伟大的建筑。无论如何，要想创造出高层建筑真正非凡的设计，两者都需要最好的。 虽然在文献中通常可以见到有关这七种体系的全面性讨论，但是在这里还值得进一步讨论。设计方法的本质贯穿于整个讨论。设计方法的本质贯穿于整个讨论中。 抗弯矩框架 抗弯矩框架也许是低，中高度的建筑中常用的体系，它具有线性水平构件和垂直构件在接头处基本刚接之特点。这种框架用作独立的体系，或者和其他体系结合起来使用，以便提供所需要水平荷载抵抗力。对于较高的高层建筑，可能会发现该本系不宜作为独立体系，这是因为在侧向力的作用下难以调动足够的刚度。 我们可以利用STRESS，STRUDL 或者其他大量合适的计算机程序进行结构分析。所谓的门架法分析或悬臂法分析在当今的技术中无一席之地，由于柱梁节点固有柔性，并且由于初步设计应该力求突出体系的弱点，所以在初析中使用框架的中心距尺寸设计是司空惯的。当然，在设计的后期阶段，实际地评价结点的变形很有必要。 支撑框架 支撑框架实际上刚度比抗弯矩框架强，在高层建筑中也得到更广泛的应用。这种体系以其结点处铰接或则接的线性水平构件、垂直构件和斜撑构件而具特色，它通常与其他体系共同用于较高的建筑，并且作为一种独立的体系用在低、中高度的建筑中。
Optimum blank design of an automobile sub-frame Jong-Yop Kim a ,Naksoo Kim a,*,Man-Sung Huh b a Department of Mechanical Engineering,Sogang University,Shinsu-dong 1,Mapo-ku,Seoul 121-742,South Korea b Hwa-shin Corporation,Young-chun,Kyung-buk,770-140,South Korea Received 17July 1998 Abstract A roll-back method is proposed to predict the optimum initial blank shape in the sheet metal forming process.The method takes the difference between the ?nal deformed shape and the target contour shape into account.Based on the method,a computer program composed of a blank design module,an FE-analysis program and a mesh generation module is developed.The roll-back method is applied to the drawing of a square cup with the ˉange of uniform size around its periphery,to con?rm its validity.Good agreement is recognized between the numerical results and the published results for initial blank shape and thickness strain distribution.The optimum blank shapes for two parts of an automobile sub-frame are designed.Both the thickness distribution and the level of punch load are improved with the designed blank.Also,the method is applied to design the weld line in a tailor-welded blank.It is concluded that the roll-back method is an effective and convenient method for an optimum blank shape design.#2000Elsevier Science S.A.All rights reserved. Keywords:Blank design;Sheet metal forming;Finite element method;Roll-back method
本科毕业设计(论文) 外文参考文献译文及原文 学院信息工程学院 专业信息工程 年级班别 学号 学生姓名 指导教师
目录 译文 (1) 基于单片机的开关电源 (1) 1、用途 (1) 2、简介 (1) 3、分类 (2) 4、开关电源的分类 (3) 5、技术发展动向 (4) 6、原理简介 (6) 7、电路原理 (7) 8、DC/DC变换 (8) 9、AC/DC变换 (8) 原文 (10) The design Based onsingle chip switching power supply (10) 1、uses (10) 2、Introduction (10) 3、classification (11) 4、the switching power supply. (13) 5、technology developments (14) 6、the principle of Introduction (17) 7、the circuit schematic (18) 8、the DC / DC conversion (19) 9, AC / DC conversion (20)
译文 基于单片机的开关电源 1、用途 开关电源产品广泛应用于工业自动化控制、军工设备、科研设备、LED 照明、工控设备、通讯设备、电力设备、仪器仪表、医疗设备、半导体制冷制热、空气净化器，电子冰箱，液晶显示器，LED灯具，通讯设备，视听产品，安防，电脑机箱，数码产品和仪器类等领域。 2、简介 随着电力电子技术的高速发展，电力电子设备与人们的工作、生活的关系日益密切，而电子设备都离不开可靠的电源，进入80年代计算机电源全面实现了开关电源化，率先完成计算机的电源换代，进入90年代开关电源相继进入各种电子、电器设备领域，程控交换机、通讯、电子检测设备电源、控制设备电源等都已广泛地使用了开关电源，更促进了开关电源技术的迅速发展。 开关电源是利用现代电力电子技术，控制开关晶体管开通和关断的时间比率，维持稳定输出电压的一种电源，开关电源一般由脉冲宽度调制（PWM）控制IC和开关器件（MOSFET、BJT等）构成。开关电源和线性电源相比，二者的成本都随着输出功率的增加而增长，但二者增长速率各异。线性电源成本在某一输出功率点上，反而高于开关电源。随着电力电子技术的发展和创新，使得开关电源技术在不断地创新，这一成本反转点日益向低输出电力端移动，这为开关电源提供了广泛的发展空间。 开关电源高频化是其发展的方向，高频化使开关电源小型化，并使开关电源进入更广泛的应用领域，特别是在高新技术领域的应用，推动了高新技术产品的小型化、轻便化。另外开关电源的发展与应用在节约能源、节约资源及保护环境方面都具有重要的意义。
Construction of rock or soil in the construction. It is a modern city of high-speed product development, the city will again ease the contradictions of the role to improve the living environment, but also opened up new human life. Rational development and utilization of human natural and artificial excavation of the underground space, not only help to ease the development of modern urban contradictions, to improve the living environment, but also to open up a new human life. Because of the large-scale development of underground construction, underground architecture is taking shape, its research includes the history of development of underground construction and development of underground space development and utilization of underground space in urban planning, various types of underground construction planning and design, as well as underground construction and related environmental, physiological, psychological and technical issues. Underground construction has a good protective performance, better thermal stability and confined, as well as an integrated economic, social and environmental benefits. Underground construction in a certain thickness of rock or soil, you can avoid or reduce nuclear weapons, conventional weapons, chemical and biological weapons of destruction, while at the same time more effectively to resist earthquakes, hurricanes and other natural disasters. Underground construction in and around the confined environment of relatively stable existence of the temperature field, temperature, or for creating ultra-clean manufacturing environment and at low temperatures or under high-temperature storage of materials, pollution prevention, especially for energy conservation as well. In the city planned the construction of underground construction, urban land use for savings, lower building density, to improve urban transportation, the