注塑模外文翻译

注塑成型智能模具设计工具

摘要

注塑成型是一个生产热塑性塑料制品最流行的制造工艺，而模具设计是这个过程的一个重要方面。模具设计需要专业的知识、技能，最重要的是拥有该领域的经验。三者缺一不可。生产塑料组件需要选择恰当的模具，如果缺乏其中之一，这种选择就得在反复试验的基础上进行。这会增加生产成本，并造成设计上的不一致。本文介绍了智能模具设计工具的发展。该工具捕获模具设计过程的知识，并且以符合逻辑的方式将这些知识反映出来。所获得的知识将是确定性的，但模具设计过程中的信息是非确定的。一旦开发了模具设计工具，它将指导使用者根据不同客户的要求，为其塑料零件选择合适的模具。

导言

注塑成型工艺过程需要专业的知识、技能，最重要的是需要它成功的实践经验。通常是工艺参数控制过程的效率。在制造过程中，有效地控制和优化这些参数能实现一致性，这种一致性会在零件质量和零件成本上表现出来的问题。

1 智能化工程模块注塑成型工艺（IKEM）

基于知识的智能化工程模块的注塑成型工艺（IKEM）是一种软件技术，它领先于并行工程和 CAD / CAM 系统。它集成工程的设计和制造工艺的最新知识，给用户各种设计方面的指示，通过减少在产品开发设计阶段的工程变更，有助于减少一些工时。该系统将用于注塑设计，设计迭代和流程整合。目前的过程由许多手工计算、CAD 图形结构和从以前项目取得的经验三部分组成。一旦工程师完成设计，这将是性能评估。该 IKEM 项目已分为三大模块。

1 费用估算模块

2 模具设计模块

3 生产模块

IKEM 系统有两种形式输入。在一个 CAD 模型的形式（Pro/E 文件）下输入，和在给出的用户界面形式下输入。制造商的经验水平将决定如何有效地控制工艺参数。有时这就导致人为错误引起的不一致性。还有经验不足，时间、资源短缺和创新的空间不大的情况。通过创造所谓的“智能模型”的问题，工程学知识提供了一个可行的方案去解决所有这样用户输入形式模架设计制造用户输出形式语法分析程 CAD 模型成本估计

2 智能模具设计工具

在它的基本形式中模具设计工具是一个从文本文件中提取输入的 Visual Basic 应用程序，这种文本文件包含关于零件和用户输入程序。该文本文件包含来自 Pro/E 的一个信息文件的零件的几何解析。输入是用来估测模具得尺寸和其它各种特性。

2.1 文献回顾

模具设计的是另一种注塑成型过程的阶段，有经验的工程师在很大程度上有助于自动化进程，提高其效率。这个问题需要注意的是深入研究设计模具的时间。通常情况下，当设计工程师设计模具时，他们会参阅表格和标准手册，这会消耗大量的时间。另外，在标准的CAD 软件中需要大量的时间去考虑模具的建模组件。不同的研究人员已经解决了缩短用不同的方式来设计模具所花费的时间的问题。凯尔奇和詹姆斯采用成组技术来减少模具设计时间。聚合一类注塑成型件的独特的编码系统和在注射模具中所需的工具已开发，它可以适用于其它产品生产线。实施编码系统的软件系统也已经被开发。通过获取在这方面领域的工程师的经验和知识，尝试直接使模具设计过程的自动化。并行模具设计系统的研究开发就是这样的一个过程，在并行工程环境中试图制定一个系统的注塑模具设计流程。他们的研究目标是研制一个有利于并行工程实践的模具开发的进程，和研制开发一个以知识为基础的为注塑模具设计提供工艺问题和产品要求的辅助设计。通过各种方式获取关于模具设计过程的确定信息和

不确定信息，研究人员一直试图使模具设计流程自动化。这个研究试图研制开发一个独特的模具设计应用程序，它以确定性和不确定性两种形式获取信息。

2.2 采用的方法

为了发展智能模具设计工具，传统的模具设计方法在被研究。应用程序开发人员和设计工程师合作设计一种特定塑料零件的模具。在此期间，被工程师采纳用来选择模底座的方法正在被地密切关注和筛选过程的各个方面，需要他的知识经验来确定。此外，有时候工程师将参考图表和手册以规范其甄选过程。这耗费时间的过程，稍后也被记录在应用程序中。

系统的阐述依据输入和输出的应用程序是下一阶段。这涉及到如何定义什么养的模具布局信息是用户最需要的，也是他输入最少却得到相同的输出。

根据在模具设计工作中收集到的信息，由工程师遵循的公约被转化为if - then 规则。决策表是用来解释各种可能出现的情况，它们是当处理模具设计工程中某一特定的方面所提出的。这样被制定规则，然后被组织在相互交融的模块中，使用应用程序开发环境。最后，应用程序是检验其正确性，当涉及到为塑料零件设计模具在工业生产中。

2.3 选择合适的模架

通常情况下，为制造塑料零件选择适当的模架所涉及的有：

（1）估计模腔数模腔数量的决定取决于在一定时间内所需部件的数量，像机器的塑化能力，废品率等问题也会影响到模架的模腔数量。

（2）确定镶块及其尺寸镶块有助于模架重用，因此有助于降低生产成本。当涉及到尺寸和数量的选择，作出决定取决于现有的镶块的重用性和新的镶块的成本。

（3）确定浇道的尺寸和定位浇道的尺寸取决于所成型的材料。尽管还有其它要考虑材料特性来决定它的浇道的尺寸供符合它的流量要求。转轮的定位，取决于所用流道的拓扑布局。虽然循环的浇道系统始终是最好的，支道系统的平衡，避免流道均衡补偿的树枝状浇道系统是一个最被广泛应用的系统。

（4）确定浇道直径浇道直径决定于模具的尺寸，模腔的数量或在一定的时间内

用来填补的塑料的总数。

（5）浇口的定位塑料在某一点进入模腔，在这点可以均匀填充满模腔。浇口可

以设在循环模腔的任何周围点，但当填补矩形腔时，必须从中部流进。

（6）确定供水道的的尺寸和定位供水道之间和从模具中的任何壁上以标准的距

离定位。该公约不是用一个直径范围定位水道在模具壁上。

（7）根据以上结论确定模具的尺寸根据以上的所有结论，模具的大概尺寸可以

被估计，并四舍五入至最接近的产品目录号。在模架以前，如果重新设计，考虑到以上所有方面会降低成本和减少设计时间，进入重新设计。

2.4 问题的提出

建立问题，需要人的知识和经验，模具设计方面消耗的时间涉及到图表，数据表等，为开发应用程序的问题解释。虽然大部分的输入如模腔数、腔的图像尺寸、周期时间，都是根据客户要求，其他输入如塑化能力、每分钟注射量等，可从机器的说明书中获得。应用程序的输出包含模具尺寸和其他资料，这显然有助于在目录中选择标准模架。

Intelligent Mold Design Tool For Plastic Injection Molding Abstract

Plastic Injection molding is one of the most popular manufacturing processes for making thermo plastic products and mold design is a key aspect of the process. Design of molds requires knowledge expertise and most importantly experience in the field. When one of these is lacking selection of an appropriate mold for manufacturing a plastic component is done on a trial-and-error basis. This increases the cost of production and introduces inconsistencies in the design. This paper describes the development of an intelligent mold design tool. The tool captures know ledge about the mold design process and represents the knowledge in logical fashion. The knowledge acquired will be deterministic and non-deterministic information about the mold design process. Once developed the mold design tool will guide the user in selecting an appropriate mold for his plastic part based on various client specifications.

Introduction

The plastic injection molding process demands knowledge expertise and most important experience for its successful implementation. Often it is the molding parameters that control the efficiency of the process. Effectively controlling and optimizing these parameters during the manufacturing process can achieve consistency which takes the form of part quality and part cost. The level of experience of the manufacturers determines how effectively the process parameters are controlled. This sometimes leads to inconsistency introduced by human error. There is also the case where there is inexperience shortage of time resources and little scope for innovation. Knowledge-based engineering provides a feasible solution to all these problems by creating what is called an “intelligent model” of the problem.

1 IKEM

Intelligent Knowledge based Engineering modules for the plastic injection molding process IKEM is a software technology that is a step ahead of the concurrent engineering and CAD/CAM systems. It integrates current knowledge about the design and manufacturing processes and helps to reduce several man-hours by reducing engineering changes in the design phase of product development by giving users instruction about various design aspects. The system will be used for injection molding design design iterations and process integration. The current process consists of many manual computations CAD graphical constructions and experience attained from previous projects. Once the engineer completes the design it will be evaluated for performance. The IKEM project has been divided into three major modules.

1. The cost estimation module

2. The mold design module

3. The Manufacturing module

Input to the IKEM system is of two forms. Input in the form of a CAD model Pro-E file and input given at the User Interface form. The manufacturer's level of experience will determine how to effectively control the process parameters. Sometimes this leads to inconsistency caused by human error. There is lack of experience, lack of time, lack of resources and innovative space. Through the creation of a "smart" model, engineering knowledge provides a feasible scheme to solve all user input form mold design and manufacture of the user output form of syntax analysis process CAD model cost estimation

2 Intelligent Mold Design Tool

The mold design tool in its basic form is a Visual Basic application taking input from a textfile

that contains information about the part and a User Input form. The text file containsinformation about the part geometry parsed from a Pro/E information file. The input is used toestimate the dimensions of mold and various other features.

2.1 Literature Review

Design of molds is another stage of the injection molding process where the experience of an engineer largely helps automate the process and increase its efficiency. The issue that needs attention is the time that goes into designing the molds. Often, design engineers refer to tables and standard handbooks while designing a mold, which consumes lot of time. Also, a great deal of time goes into modeling components of the mold in standard CAD software. Different researchers have dealt with the issue of reducing the time it takes to design the mold in different ways. Koelsch and James have employed group technology techniques to reduce the mold design time. A unique coding system that groups a class of injection molded parts, and the tooling required in injection molding is developed which is general and can be applied toother product lines.

A software system to implement the coding system has also been developed. Attempts

were also directed towards the automation of the mold design process by capturing experience and knowledge of engineers in the field. The development of a concurrent mold design system is one such approach that attempts to develop a systematic methodology for injection mold design processes in a concurrent engineering environment. The objective of their research was to develop a mold development process that facilitates concurrent

engineering-based practice, and to develop a knowledge-based design aid for injection molding mold design that accommodates manufacturability concerns, as well as product requirements.

Researchers have been trying to automate the mold design process either by capturing only the deterministic information on the mold design process or the non-deterministic information, in various ways. This research uniquely attempts to develop a mold design application that captures information in both forms; deterministic and non-deterministic.

2.2 Approach Adopted

In order to develop an intelligent mold design tool, the conventional method of designing molds is studied. The application developer and the design engineer work together in designing a mold for a particular plastic part. During this time, the approach adopted by the engineer to select the mold base is closely observed and aspects of the selection process that require his knowledge/experience are identified. Also, there will be times when the engineer will refer to tables and handbooks in order to standardize his selection process. This time consuming process is also recorded to incorporate it later in the application.

Formulating the problem for the application in terms of inputs and outputs is the next

stage. This involves defining what information about the mold layout is most required for the user and also the minimum number of inputs that can be taken from him to give those outputs.

Based on the information gathered in the mold design exercise, the conventions followed by the engineer are transformed into if-then rules. Decision tables are used to account for all possible cases that arise when dealing with a particular aspect of the mold design process. The rules so framed are then organized into modules interacting with each other, using an application development environment. Finally the application is tested for its validity when it comes to

designing molds for plastic parts manufactured in the industry.

2.3 Selection of Appropriate Mold Base

Typically, selection of appropriate mold base for manufacturing a plastic part involves

Estimating the number of cavities

The number of cavities is decided depending on the number of parts required within a given time. There are also other issues like the plasticizing capacity of the machine, reject rate etc that affect the number of cavities to be present in the mold base.

Deciding on the presence of inserts and their dimensions

Inserts facilitate the reusability of the mold base and therefore help in reducing cost of manufacturing. When it comes to selecting the dimensions and the number, a decision is made depending on the reusability of existing old inserts and cost of ordering new ones.

Determining the size and location of runners

The runner size depends on the material being molded. Although there are other considerations material properties determines the channel size required for its flow. Location of runners mainly depends on the topology of runners being used. Though a circular runner system is always preferable, the branched runner system that avoids runner balancing is the one most widely used.

Determining the diameter of sprue

The diameter of the sprue is decided based on the size of the mold, number of cavities, or the amount of plastic that is to be filled within a given time.

Locating gates

Plastic enters the cavity at a point where it can uniformly fill the cavity. A gate can be located at any point on the perimeter of a circular cavity but has to enter at the midsection when it comes to filling rectangular cavities.

Determining the size and location of water lines

Water lines are located at standard distances form each other and from any wall in the mold. The convention is not to locate a waterline within one diameter range on the mold wall.

Deciding mold dimensions based on above conclusions

Based on all the above decisions the approximate mold dimensions can be estimated and rounded off to the nearest catalog number. Considering all the above aspects before even modeling the mold base reduces the cost and time that go into redesigning.

2.4 Formulation of the Problem

Based on issues that require human knowledge/experience, and aspects of mold designthat consume time referring to tables, data sheets etc.. While most of the input, like the number of cavities, cavity image dimensions, cycle time are based on the client specifications, other input like the plasticizing capacity, shots per minute etc., can be obtained from the machine specifications. The output of the application contains mold dimensions and other information, which clearly helps in selecting the standard mold base from catalogs.

英文文献翻译

中等分辨率制备分离的 快速色谱技术 W. Clark Still,* Michael K a h n , and Abhijit Mitra Departm(7nt o/ Chemistry, Columbia Uniuersity,1Veu York, Neu; York 10027 ReceiLied January 26, 1978 我们希望找到一种简单的吸附色谱技术用于有机化合物的常规净化。这种技术是适于传统的有机物大规模制备分离，该技术需使用长柱色谱法。尽管这种技术得到的效果非常好，但是其需要消耗大量的时间，并且由于频带拖尾经常出现低复原率。当分离的样本剂量大于1或者2g时，这些问题显得更加突出。近年来，几种制备系统已经进行了改进，能将分离时间减少到1-3h，并允许各成分的分辨率ΔR f≥（使用薄层色谱分析进行分析）。在这些方法中，在我们的实验室中，媒介压力色谱法1和短柱色谱法2是最成功的。最近，我们发现一种可以将分离速度大幅度提升的技术，可用于反应产物的常规提纯，我们将这种技术称为急骤色谱法。虽然这种技术的分辨率只是中等（ΔR f≥），而且构建这个系统花费非常低，并且能在10-15min内分离重量在的样本。4 急骤色谱法是以空气压力驱动的混合介质压力以及短柱色谱法为基础，专门针对快速分离，介质压力以及短柱色谱已经进行了优化。优化实验是在一组标准条件5下进行的，优化实验使用苯甲醇作为样本，放在一个20mm*5in.的硅胶柱60内，使用Tracor 970紫外检测器监测圆柱的输出。分辨率通过持续时间（r）和峰宽（w,w/2）的比率进行测定的（Figure 1），结果如图2-4所示，图2-4分别放映分辨率随着硅胶颗粒大小、洗脱液流速和样本大小的变化。

外文翻译 外文文献 英文文献 胜任力模型研究

Research on Competency Model:A Literature Review and Empirical Studies Abstract Western countries have applied competency models to addressing problems existed in their administrative and managerial systems since 1970s，and the findings is positine and promising. However, competency model hasn’t been introduced to China until 1990s and it is still unknown and mysterious to many Chinese managers. This paper aims to uncover the mysterious veil of competency model in order to broaden the horizon of Chinese managers and boost China's human resource development as well as management. Keywords:Competency，Competency Models，Empirical Studies of Competency Models It has been more than 30 years since competency model was utilized to human resource management.In western countries，competency model first displayed its effectiveness in government administration, meanwhile many multinationals and their branch companies applied the competency model to their daily business management and their business was a great success. As the notion of competency is gradually come to light and accepted by people all around the world，more and more enterprises have been trying to build their own competency model under the help of professional consultant firms. As a result，competency model has gradually been a very fashionable phrase in the field of management and quite a few enterprises are thus benefited from it. In recent years, competency model has become a hot spot in the Chinese academia as well as big-，middle- and small-sized enterprises alike，many relevant writings and books have also been translated and published. However, competency and competency model are still mysterious to many Chinese scholars, business managers as well as government administrators. Purpose and Significance of the Study The purpose of the study aims to make a critical literature review of the competency model，clarify some confusion related to it and explore its application. The following questions are employed to guide this study:What is competency? What is competency model? What are the theoretical and empirical findings related to competency model? The study illustrates how we could take advantage of competency model in our harmonious society building. On one hand，the study will delineate competency and competency model in order to clarify confusions related to it since it is still strange and mysterious to many Chinese managers and administrators;on the other hand，the

cmos4046集成电路研究锁相环(pll)的工作原理毕业外文翻译

本实验要使用CMOS4046集成电路研究锁相环（PLL ）的工作原理。电路包括两个不同的鉴相器和一个VCO 。另外还有一个齐纳二极管参考电压源用在供电调节中，在解调器输出中有一个缓冲电路。用户必须提供环路滤波器。4046具有高输入阻抗和低输出阻抗，容易选择外围元件。 注意事项 1. 本实验较为复杂，进入实验室之前，确认你已经弄懂了电路预计应该怎样工作。对某样东西还没有充分分析之前，不要去尝试制作它。在开始实验之前要通读本文。 2. 在实验第一部分得到的数据要用来完成实验的其它任务。 所以要仔细对待这部分内容。 3. 小心操作4046芯片，CMOS 集成电路很容易损坏。避免静电释放，使用10k Ω电阻把信号发生器的输出耦合到 PLL 。在关掉4046供电电源之前先关闭信号发生器，或者从信号输入端给整个电路供电。要避免将输出端对电源或对地短路，TTL 门电路可以容忍这种误操作但 CMOS 不能（要注意松散的导线）。CMOS 输出也没有能力驱动电容负载。VSS 应该接地，VDD 应该接5V ，引脚5应该接地（否则VCO 被禁止）。 1 VCO 工作原理 阅读数据手册中的电路描述。 VCO 常数（0K 单位为弧度/秒-伏）是工作频率 变化与输入电压（引脚9上）变化之比值。测量出0K ，即，画出输出频率关于 输入电压的曲线。确认数据范围要覆盖5kHz 到50kHz 。对于R1, R2 和C 的各种参数取值进行测量，确定 0K 对于R1 ,R2 和C 是怎样的近似关系。测量VCO 输出的上升和下降时间，研究电容性负载的影响。2 无源环路滤波器 无源环路滤波器位于鉴相器输出与VCO 输入之间。此滤波器对鉴相器输出中 的高次谐波进行衰减，并控制环路的强度。通常用一个简单 RC 滤波器就可以满足要求，这种设计能避免有源滤波器设计中固有的电平移动和输出限制的恼人问 题。但另外一方面，有源滤波器可以提供更优越的性能。 2.1 相位比较器首先来看一下4046的相位比较器II 的输出。该输出端是一个三态器件，这可以在环路锁定时减小波纹。与存在两倍基频拍频的情况不同，这里没有任何拍频。糟糕的方面是，当我们需要为环路建立一个框图时， D K 却不能很好地定义。当向上或向下驱动之一接通时，输出端表现为电压源。但是当输出端悬浮时，它实质上为一个电流源（一个 0A 电流源）。因此D K 的值将依赖于给定的滤波器。考 察图1。 图1 相位比较器II 的输出 图中当向上驱动器接通时，相位比较器输出为 5PO v V ，当向下驱动器接通时，0PO v V ，当相位比较器处在开路状态时，PO D v v 。我们可以求出输出的平均值：

计算机网络-外文文献-外文翻译-英文文献-新技术的计算机网络

New technique of the computer network Abstract The 21 century is an ages of the information economy, being the computer network technique of representative techniques this ages, will be at very fast speed develop soon in continuously creatively, and will go deep into the people's work, life and study. Therefore, control this technique and then seem to be more to deliver the importance. Now I mainly introduce the new technique of a few networks in actuality live of application. keywords Internet Network System Digital Certificates Grid Storage 1. Foreword Internet turns 36, still a work in progress Thirty-six years after computer scientists at UCLA linked two bulky computers using a 15-foot gray cable, testing a new way for exchanging data over networks, what would ultimately become the Internet remains a work in progress. University researchers are experimenting with ways to increase its capacity and speed. Programmers are trying to imbue Web pages with intelligence. And work is underway to re-engineer the network to reduce Spam (junk mail) and security troubles. All the while threats loom: Critics warn that commercial, legal and political pressures could hinder the types of innovations that made the Internet what it is today. Stephen Crocker and Vinton Cerf were among the graduate students who joined UCLA professor Len Klein rock in an engineering lab on Sept. 2, 1969, as bits of meaningless test data flowed silently between the two computers. By January, three other "nodes" joined the fledgling network.

论文外文文献翻译3000字左右

南京航空航天大学金城学院 毕业设计（论文）外文文献翻译 系部经济系 专业国际经济与贸易 学生姓名陈雅琼学号2011051115 指导教师邓晶职称副教授 2015年5月

Economic policy,tourism trade and productive diversification （Excerpt） Iza Lejárraga,Peter Walkenhorst The broad lesson that can be inferred from the analysis is that promoting tourism linkages with the productive capabilities of a host country is a multi-faceted approach influenced by a variety of country conditions.Among these,fixed or semi-fixed factors of production,such as land,labor,or capital,seem to have a relatively minor influence.Within the domain of natural endowments,only agricultural capital emerged as significant.This is a result that corresponds to expectations,given that foods and beverages are the primary source of demand in the tourism economy.Hence,investments in agricultural technology may foment linkages with the tourism market.It is also worth mentioning that for significant backward linkages to emerge with local agriculture,a larger scale of tourism may be important. According to the regression results,a strong tourism–agriculture nexus will not necessarily develop at a small scale of tourism demand. It appears that variables related to the entrepreneurial capital of the host economy are of notable explanatory significance.The human development index(HDI), which is used to measure a country's general level of development,is significantly and positively associated with tourism linkages.One plausible explanation for this is that international tourists,who often originate in high-income countries,may feel more comfortable and thus be inclined to consume more in a host country that has a life-style to which they can relate easily.Moreover,it is important to remember that the HDI also captures the relative achievements of countries in the level of health and education of the population.Therefore,a higher HDI reflects a healthier and more educated workforce,and thus,the quality of local entrepreneurship.Related to this point,it is important to underscore that the level of participation of women in the host economy also has a significantly positive effect on linkages.In sum, enhancing local entrepreneurial capital may expand the linkages between tourism and other sectors of the host country.

外文文献及翻译

To connect SQL Server database First we introduce the basic knowledge of the database,be regarded as the warm-up exercise that study database weave distance front! 1.warm-up exercise Needing first avowal is relation database that database knowledge that we here introduce all point. The so-called relation database is to mean data as that the form gather, passing to establish simple form an a kind of database for of relation to defining construction. I ignore the watch at how saving way in physics in the document in database is,it can see to make an a line for with row, with electronics form is similar with the row.In relation database, the line were called the record, but the row then is called word segment. This form inside each an all in formations for is a record, it including particular customer, but each record then included the same type with the word segment of the quantity:Customer's number, name etc. Form is logic set that a kind of related information that press a line of arranging with row, similar in single form in work. Each row of the word a database form inside calls a word segment. Watch is from every kind of word a definition of its containment of, each word a data for describing its implying. While creating to set up a database, the beard assign for each word segment a the piece belongs to the sex with the other according to the type,biggest length.The word segment can include every kind of word sign,arithmetic figure even sketch. An information of relevant customer deposits in the line of the form, is called record.By any large, arbitrarily two records for database form to create set up can't be same. Key be a certain word segment( or several words segment) of the form inside, it() for fast inspect but drive index. The key can be unique, and also can then the right and wrong is unique, being decided by it() whether admission repetition. Unique key can specify for main key, using each one that come to unique marking form. The norm turns the database design of mission be method that the data of buildup,but the data of buildup, should can dissolve otiose repetition, and for have the necessary information offering to check to seek the path quickly. For attaining this kind of target but separate information to the process gone to in every kind of independent form, be called the norm turn. It is complicated process to use many appointed rules to proceed the norm with the type of the different Class that norm turn. That process studies and discuss already beyond the reach of textual scope.But,the norm of the simple database in majority turn and can use the simple experience in underneath rule completes: include the form of the information of repetition must be divided into independent a few forms dissolve repetition.

基于Multisim的锁相环解调系统仿真毕业论文

基于Multisim的锁相环解调系统仿真毕业论文 目录 第1章绪论 (1) 1.1 研究背景 (1) 1.2 研究现状 (1) 1.3 研究容介绍 (2) 第2章基本原理 (3) 2.1 Multisim介绍 (3) 2.2 锁相环基本原理 (5) 2.2.1锁相环的基本组成 (5) 2.2.2 锁相环的工作原理 (5) 第3章调制解调电路设计 (8) 3.1 2FSK调制解调电路设计 (8) 3.1.1 2FSK调制电路设计原理 (8) 3.1.2 2FSK调制单元电路的设计 (9) 3.1.3 2FSK解调单元电路的设计 (13) 3.1.4 2FSK解调电路的整体设计 (15) 3.2 2PSK调制解调电路设计 (17) 3.2.1 2PSK调制解调电路设计原理 (17) 3.2.2 2PSK调制与解调电路的设计与仿真 (18) 3.3 2ASK调制解调电路设计 (19) 3.3.1 2ASK调制解调电路设计原理 (19) 3.3.2 2ASK调制与解调电路的设计与仿真 (20) 3.4 解调结果分析 (22) 总结 (24) 参考文献 (25) 附录：(外文翻译) (26)

致谢 (50)

第1章绪论 1.1 研究背景 实现调频波解调的方法有很多，而锁相环鉴频是利用现代锁相环技术来实现鉴频方法，具有工作稳定失真小，信噪比高等优点，所以被广泛用在通信电路系统中。锁相环路是一种反馈电路，锁相环的英文全称是Phase-Locked Loop，简称PLL。其作用是使得电路相位同步。因锁相环可以实现输出信号频率对输入信号频率的自动跟踪，所以锁相环通常用于闭环跟踪电路。锁相环在工作的过程中，当输出信号的频率与输入信号的频率相等时，输出电压与输入电压保持固定的相位差值，即输出电压与输入电压的相位被锁住，它还具有载波跟踪特性。作为一个窄带跟踪滤波器，可提取淹没在噪声中的信号；用高稳定的参考振荡器锁定，可提供高稳定的频率源；可进行高精度的香味与频率测量等等。如今锁相环解调器在通信、雷达、测量和自动化控制等领域应用极为广泛，随着电子技术的发展，对锁相环解调的研究和应用得到了越来越多的关注。 现在通过分析与研究，加深对锁相环解调方式的理解，并根据它的原理，设计出2FSK、2PSK、2ASK的调制电路，并通过锁相环解调出来。 1.2 研究现状 锁相环解调技术的发展十分迅速，如今已经在很多领域都应用了锁相环解调的理论。可用于手机中、SDH网络中、在汽车MP3无线发射器中‘测量汽车转速都是十分典型的应用。调频波的特点是频率随调制信号幅度的变化而变化，压控振荡器的振荡频率取决于输入电压的幅度。当载波信号的频率与锁相环的固有振荡频率ω0相等时，压控振荡器输出信号的频率将保持ω0不变。若压控振荡器的输入信号除了有锁相环低通滤波器输出的信号uc外，还有调制信号ui，则压控振荡器输出信号的频率就是以ω0为中心，随调制信号幅度的变化而变化的调频波信号。当然，锁相环的许多优越性使得锁相环解调技术在很多我们周围都可以见到的物品中发挥着其巨大的功效。 如今，锁相环路理论与研究日臻完善，应用围遍及整个电子技术领域。随着通信及电子系统的飞速发展，促使集成锁相环和数字锁相环突飞猛进。现在品种齐全繁多，提高系统的工作稳定性和可靠性和小型化，目前仍朝着集成化，数字化，多用化方向迅速发展。

环境设计城市与景观毕业设计外文翻译中英文

I. City and The Landscape (1) Overview of Landscape Design Landscape design, first, is a people's thinking activity, performed as an art activity.Diversified thoughts formed complex diverse landscape art style. Contemporary landscape design apparently see is the diversity of the landscape forms,in fact its essence is to keep the closing up to the natural order system, reflected the more respect for human beings, more in-depth perspective of the nature of human's reality and need, not to try to conquer the nature.it is not even imitating natural, but produce a sense of belonging. Landscape is not only a phenomenon but the human visual scene. So the earliest landscape implications is actually city scene. Landscape design and creation is actually to build the city. (2) The Relationship Between Landscape and Urban City is a product of human social, economic and cultural development, and the most complex type. It is vulnerable to the artificial and natural environmental conditions of interference. In recent decades, with worldwide the acceleration of urbanization, the urban population intensive, heavy traffic, resource shortage,

变电站_外文翻译_外文文献_英文文献_变电站的综合概述

英文翻译 A comprehensive overview of substations Along with the economic development and the modern industry developments of quick rising, the design of the power supply system become more and more completely and system. Because the quickly increase electricity of factories, it also increases seriously to the dependable index of the economic condition, power supply in quantity. Therefore they need the higher and more perfect request to the power supply. Whether Design reasonable, not only affect directly the base investment and circulate the expenses with have the metal depletion in colour metal, but also will reflect the dependable in power supply and the safe in many facts. In a word, it is close with the economic performance and the safety of the people. The substation is an importance part of the electric power system, it is consisted of the electric appliances equipments and the Transmission and the Distribution. It obtains the electric power from the electric power system, through its function of transformation and assign, transport and safety. Then transport the power to every place with safe, dependable, and economical. As an important part of power’s transport and control, the transformer substation must change the mode of the traditional design and control, then can adapt to the modern electric power system, the development of modern industry and the of trend of the society life. Electric power industry is one of the foundations of national industry and national economic development to industry, it is a coal, oil, natural gas, hydropower, nuclear power, wind power and other energy conversion into electrical energy of the secondary energy industry, it for the other departments of the national economy fast and stable development of the provision of adequate power, and its level of development is a reflection of the country's economic development an important indicator of the level. As the power in the industry and the importance of the national economy, electricity transmission and distribution of electric energy used in these areas is an indispensable component.。Therefore, power transmission and distribution is critical. Substation is to enable superior power plant power plants or power after adjustments to the lower load of books is an important part of power transmission. Operation of its functions, the capacity of a direct impact on the size of the lower load power, thereby affecting the industrial production and power consumption.Substation system if a link failure, the system will protect the part of action. May result in power outages and so on, to the production and living a great disadvantage. Therefore, the substation in the electric power system for the protection of electricity reliability,

外文文献翻译助手

五分钟搞定5000字－外文文献翻译 在科研过程中阅读翻译外文文献是一个非常重要的环节，许多领域高水平的文献都是外文文献，借鉴一些外文文献翻译的经验是非常必要的。由于特殊原因我翻译外文文献的机会比较多，慢慢地就发现了外文文献翻译过程中的三大利器：Google“翻译”频道、金山词霸（完整版本）和CNKI“翻译助手"。 具体操作过程如下： 1.先打开金山词霸自动取词功能，然后阅读文献； 2.遇到无法理解的长句时，可以交给Google处理，处理后的结果猛一看，不堪入目，可是经过大脑的再处理后句子的意思基本就明了了； 3.如果通过Google仍然无法理解，感觉就是不同，那肯定是对其中某个“常用单词”理解有误，因为某些单词看似很简单，但是在文献中有特殊的意思，这时就可以通过CNKI的“翻译助手”来查询相关单词的意思，由于CNKI的单词意思都是来源与大量的文献，所以它的吻合率很高。 另外，在翻译过程中最好以“段落”或者“长句”作为翻译的基本单位，这样才不会造成“只见树木，不见森林”的误导。 注： 1、Google翻译：https://www.sodocs.net/doc/178055977.html,/language_tools google，众所周知，谷歌里面的英文文献和资料还算是比较详实的。我利用它是这样的。一方面可以用它查询英文论文，当然这方面的帖子很多，大家可以搜索，在此不赘述。回到我自己说的翻译上来。下面给大家举个例子来说明如何用吧 比如说“电磁感应透明效应”这个词汇你不知道他怎么翻译， 首先你可以在CNKI里查中文的，根据它们的关键词中英文对照来做，一般比较准确。

在此主要是说在google里怎么知道这个翻译意思。大家应该都有词典吧，按中国人的办法，把一个一个词分着查出来，敲到google里，你的这种翻译一般不太准，当然你需要验证是否准确了，这下看着吧，把你的那支离破碎的翻译在google里搜索，你能看到许多相关的文献或资料，大家都不是笨蛋，看看，也就能找到最精确的翻译了，纯西式的！我就是这么用的。 2、CNKI翻译：https://www.sodocs.net/doc/178055977.html, CNKI翻译助手，这个网站不需要介绍太多，可能有些人也知道的。主要说说它的有点，你进去看看就能发现：搜索的肯定是专业词汇，而且它翻译结果下面有文章与之对应（因为它是CNKI检索提供的，它的翻译是从文献里抽出来的），很实用的一个网站。估计别的写文章的人不是傻子吧，它们的东西我们可以直接拿来用，当然省事了。网址告诉大家，有兴趣的进去看看，你们就会发现其乐无穷！还是很值得用的。https://www.sodocs.net/doc/178055977.html, 3、网路版金山词霸（不到1M）：https://www.sodocs.net/doc/178055977.html,/6946901637944806 翻译时的速度： 这里我谈的是电子版和打印版的翻译速度，按个人翻译速度看，打印版的快些，因为看电子版本一是费眼睛，二是如果我们用电脑，可能还经常时不时玩点游戏，或者整点别的，导致最终SPPEED变慢，再之电脑上一些词典（金山词霸等）在专业翻译方面也不是特别好，所以翻译效果不佳。在此本人建议大家购买清华大学编写的好像是国防工业出版社的那本《英汉科学技术词典》，基本上挺好用。再加上网站如：google CNKI翻译助手，这样我们的翻译速度会提高不少。 具体翻译时的一些技巧（主要是写论文和看论文方面） 大家大概都应预先清楚明白自己专业方向的国内牛人，在这里我强烈建议大家仔

外文文献翻译

估计技术和规模的希腊商业银行效率：信用风险、资产负债表的活动和 国际业务的影响1 1.介绍 希腊银行业经历了近几年重大的结构调整。重要的结构性、政策和环境的变化经常强调的学者和从业人员有欧盟单一市场的建立，欧元的介绍，国际化的竞争、利率自由化、放松管制和最近的兼并和收购浪潮。 希腊的银行业也经历了相当大的改善，通信和计算技术，因为银行有扩张和现代化其分销网络，其中除了传统的分支机构和自动取款机，现在包括网上银行等替代分销渠道。作为希腊银行（2004 年）的年度报告的重点，希腊银行亦在升级其信用风险测量与管理系统，通过引入信用评分和概率默认模型近年来采取的主要步骤。此外，他们扩展他们的产品/服务组合，包括保险、经纪业务和资产管理等活动，同时也增加了他们的资产负债表操作和非利息收入。 最后，专注于巴尔干地区（如阿尔巴尼亚、保加利亚、前南斯拉夫马其顿共和国、罗马尼亚、塞尔维亚）的更广泛市场的全球化增加的趋势已添加到希腊银行在塞浦路斯和美国以前有限的国际活动。在国外经营的子公司的业绩预计将有父的银行，从而对未来的决定为进一步国际化的尝试对性能的影响。 本研究的目的是要运用数据包络分析（DEA）和重新效率的希腊银行部门，同时考虑到几个以上讨论的问题进行调查。我们因此区分我们的论文从以前的希腊银行产业重点并在几个方面，下面讨论添加的见解。 首先，我们第一次对效率的希腊银行的信用风险的影响通过检查其中包括贷款损失准备金作为附加输入Charnes et al.(1990 年)、德雷克（2001 年）、德雷克和大厅(2003 年)，和德雷克等人（2006 年）。作为美斯特(1996) 点出"除非质量和风险控制的一个人也许会很容易误判一家银行的水平的低效；例如精打细算的银行信用评价或生产过高风险的贷款可能会被贴上标签一样高效，当相比银行花资源，以确保它们的贷款有较高的质量"(p.1026)。我们估计效率的银行和无此输入调整为不同的信用风险水平和对效率的影响。 第二，以往的研究中，希腊银行业，我们考虑资产负债表活动期间估计的效率得分。几个最近的研究审查效率的DEA 或随机前沿技术的银行，承认银行在非传统的活动中更多地参与，包括任何非利息（即费）收入（e.g. Lang和Welzel，1998年；德雷克，2001 年；托尔托萨Ausina，2003年）或资产负债表项目（例如阿尔通巴什等人，2001 年；阿尔通巴什和查克，2001年；架和Hassan，2003a、b ；Bos 和Colari，2005 年；饶， 1原文出处及作者：巴斯大学管理学院2007年硕士毕业论文，作者Fotios Pasiouras