电子工业出版社的《VC/C串口通信编程实践》是一部关于串口通信的书，内容从简单的编程实践、控件使用、无线通信等，
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空间遥感方法对压场 方向性估计。 一，导言 为外地的方向性品种的估计技术 研究文献[1] - [5]。因此，理论分析 之间的水听器阵列输出的关系 噪声场中[1]进行 - [5]。发达国家技术 是基于阵列波束输出或crossspectral 数组元素之间的产出[4] - [5矩阵]。那个 问题是在海洋领域的方向性估计使用， 水平线拖曳阵还讨论了文献[5] - [8]。最近，到达方向和领域的方向性问题 提出传感器阵列估计吸引了 新的兴趣[9] - [12]。结果表明，数组的议案 数组可以提高性能假设时间相干性 连续样本[10] - [11]。在[12]，波场 抽样方法，利用了线性关系 现场的噪音和多波束形成产出集合 各阵列方向提出。结果表明： 波场抽样（是）方法优于其他测试 方法。该算法通过实施递归 估算方法及其收敛性的独特的解决方案 是许诺的方针和一系列具体规定 波束研究方向。然而，一个正确的方法 阵列波束的方向和研究方向序列 选择仍然是一个悬而未决的问题。 该油田的方向性估计质量是决定 的角分辨率。较高的角分辨率 是，在远场的来源更准确的估计， 和更好的检测性能可以实现的。其中 在阵列信号处理的基本关系是： 的角分辨率是成正比的数目 数组的元素[13]。这种关系的愿望激励 更长的阵列，可以实现更高的分辨率。不幸地， 违反规定的实施和 安装限制，激励短阵列。而且， 较长的数组执行机动平台 如无人（无人潜航器），水下机器人，甚至可以 不可能的[14]。这些矛盾的追求激励 替代阵列信号处理方法。 通常，外地方向性被建模为有限集合 强远场窄带源和各向同性低功率 噪音[1]。在这项工作中，该字段的方向性模型 采用以下方式。首先，轴承角 空间均匀取样到大量的离散 角度。其次，假定醚的高能量 对应于远场强来源或低能量 对应于各向同性噪声的传感器接收 阵列从这些离散方位角每个。
空间压缩感应法的领域 指向性估计。 介绍。 各种技术领域的方向性估计 在文献[1],[5]。因此,进行了理论分析 水听器阵列之间的关系和输出 噪声场进行了[1],[5]。发达的技巧 基于阵列输出或crossspectral声源定位 阵列天线阵元输出之间的矩阵,[4],[5]。这个 一场的问题,利用方向性估计在海洋中 横线阵拖也在文献[5] [8]。最近,问题的波达方向与领域的方向性 估计为移动传感器阵列吸引了 新的[9],[12]。它显示一个数组的运动 可以改善数组的一致性假设颞性能 连续的样品[10]-[11]。在[12],波场 抽样方法,利用线性关系 汽车所产生的噪音和收集的声源定位。输出 各阵方向。结果显示 通过抽样的方法优于其他(WS)的测试 方法。该算法通过递归的实施 估算方法及其收敛的独特的解决方案 承诺是为某一特定的数组取向和吗 看起来问路。声源定位然而,对于一个适当的方法 数组的定位与声源定位看起来方向序列 选择仍然是个谜。 这个领域的质量评价是确定的方向性 角分辨率的。较高的分辨率 是,更准确的估计的远场源, 更好的检测性能才能得以实现。之一。 基本关系中的阵列信号处理是那个 角分辨率的数量成正比 这个数组的元素[13]。这种关系的愿望激励 长阵列,可达到更高的分辨率。不幸的是, 矛盾的要求执行 安装,激发短的数组。另外, 执行长的阵列机动平台 如无人水下车辆(UUV),甚至可以 可能[14]。这些矛盾,激发探索 替代阵列信号处理方法。 通常,磁场定向被视为一个有限的集合 强窄带来源和各向同性远lowpower 噪音[1]。在这部作品中,该模型的领域的方向性 摘要采用以下方法。首先,轴承的角度 空间是均匀采样到大量的离散 角。其次,是认为乙醚高能源 与强大的远源或低能耗 这与各向同性噪音收到传感器 从每一个数组的方位角度离散。------------------------------------
基于WIN CE的ADSL线路参数研究ADSL line parameters research based on WIN CE _EMC&dq=ADSL&printsec=frontcover&source=web&ots=oJXbatzNWO&sig=fyomvlADYeB7NRS2gjTJAfpSapQ--------------Windows CE (also known officially as Windows Embedded CE since version 0[2][3], and sometimes abbreviated WinCE) is a variation of Microsoft's Windows operating system for minimalistic computers and embedded Windows CE is a distinctly different kernel, rather than a trimmed-down version of desktop W It is not to be confused with Windows XP Embedded which is NT- It is supported on Intel x86 and compatibles, MIPS, ARM, and Hitachi SuperH FeaturesWindows CE is optimized for devices that have minimal storage—a Windows CE kernel may run in under a megabyte of Devices are often configured without disk storage, and may be configured as a “closed” system that does not allow for end-user extension (for instance, it can be burned into ROM) Windows CE conforms to the definition of a real-time operating system, with a deterministic interrupt It supports 256 priority levels and uses priority inheritance for dealing with priority The fundamental unit of execution is the This helps to simplify the interface and improve execution Microsoft has stated that the ‘CE’ is not an intentional initialism, but many people believe CE stands for ‘Consumer Electronics’ or ‘Compact Edition’; users often disparagingly called it “Wince”[4] Microsoft says it implies a number of Windows CE design precepts, including “Compact, Connectable, Compatible, Companion, and E”[5] The first version, known during development under the codename “Pegasus”, featured a Windows-like GUI and a number of Microsoft's popular applications, all trimmed down for smaller storage, memory, and speed of the palmtops of the Since then, Windows CE has evolved into a component-based, embedded, real-time operating It is no longer targeted solely at hand-held Many platforms have been based on the core Windows CE operating system, including Microsoft's AutoPC, Pocket PC 2000, Pocket PC 2002, Windows Mobile 2003, Windows Mobile 2003 SE, Windows Mobile 0, Windows Mobile 6, Smartphone 2002, Smartphone 2003 and many industrial devices and embedded Windows CE even powered select games for the Sega Dreamcast, was the operating system of the controversial Gizmondo handheld, and can partially run on modified Microsoft Xbox game A distinctive feature of Windows CE compared to other Microsoft operating systems is that large parts of it are offered in source code First, source code was offered to several vendors, so they could adjust it to their Then products like Platform Builder (an integrated environment for Windows CE OS image creation and integration, or customized operating system designs based on CE) offered several components in source code form to the general However, a number of core components that do not need adaptation to specific hardware environments (other than the CPU family) are still distributed in binary form Development toolsVisual StudioLate versions of Microsoft Visual Studio support projects for Windows CE / Windows Mobile, producing executable programs and platform images either as an emulator or attached by cable to an actual mobile A mobile device is not necessary to develop a CE The NET Compact Framework supports a subset of the NET Framework with projects in C# and VBNET, but not Managed C++Platform BuilderThis programming tool is used for building the platform (BSP + Kernel), device drivers (shared source or custom made) and also the This is a one step environment to get the system up and One can also use Platform Builder to export an SDK (standard development kit) for the target microprocessor (SuperH, x86, MIPS, ARM ) to be used with another associated tool set named Embedded Visual C++ (eVC)The Embedded Visual C++ tool is for development of embedded application for Windows CE based This tool can be used standalone using the SDK exported from Platform Builder or using the Platform Builder using the Platform Manager connectivity Relationship to Windows Mobile, Pocket PC, and SmartPhoneOften Windows CE, Windows Mobile, and Pocket PC are used This practice is not entirely Windows CE is a modular/componentized operating system that serves as the foundation of several classes of Some of these modules provide subsets of other components' features ( varying levels of windowing support; DCOM vs COM), others which are mutually exclusive (Bitmap or TrueType font support), and others which add additional features to another One can buy a kit (the Platform Builder) which contains all these components and the tools with which to develop a custom Applications such as Excel Mobile/Pocket Excel are not part of this The older Handheld PC version of Pocket Word and several other older applications are included as samples, Windows Mobile is best described as a subset of platforms based on a Windows CE Currently, Pocket PC (now called Windows Mobile Classic), SmartPhone (Windows Mobile Standard), and PocketPC Phone Edition (Windows Mobile Professional) are the three main platforms under the Windows Mobile Each platform utilizes different components of Windows CE, as well as supplemental features and applications suited for their respective Pocket PC and Windows Mobile is a Microsoft-defined custom platform for general PDA use, and consists of a Microsoft-defined set of minimum profiles (Professional Edition, Premium Edition) of software and hardware that is The rules for manufacturing a Pocket PC device are stricter than those for producing a custom Windows CE-based The defining characteristics of the Pocket PC are the digitizer as the primary Human Interface Device and its extremely portable The SmartPhone platform is a feature rich OS and interface for cellular phone SmartPhone offers productivity features to business users, such as email, as well as multimedia capabilities for The SmartPhone interface relies heavily on joystick navigation and PhonePad Devices running SmartPhone do not include a touchscreen SmartPhone devices generally resemble other cellular handset form factors, whereas most Phone Edition devices use a PDA form factor with a larger Windows Mobile 5 supports USB 0 and new devices running this OS will also conform to the USB Mass Storage Class, meaning the storage on PPC can be accessed from any USB-equipped PC, without requiring any extra software, except requiring a compliant In other words, you can use it as a flash Competing productsCompetitors to consumer CE based PDA platforms like Pocket PC – the main application of Windows CE – are Java, Symbian OS, Palm OS, iPhone OS and Linux based packages like Qtopia Embedded Linux environment from Trolltech, Convergent Linux Platform from a La Mobile, and Access Linux Platform from Orange and AThe secondary usage of CE is in devices in need of graphical user interfaces, (point of sale terminals, media centers, web tablets, thin clients) as the main selling point CE is the look and feel being similar to desktop W The competition is Windows XP, Linux and graphical packages for simpler embedded operating Being an RTOS, Windows CE is also theoretically a competitor to any realtime operating system in the embedded space, like VxWorks, ITRON or eC The dominating method, however, of mixing Windows look and feel with realtime on the same hardware, is to run double operating systems using some virtualization technology, like TRANGO Hypervisor from TRANGO Virtual Processors or Intime from TenAsys in the case of Windows, and OS Ware from VirtualLogix, Padded Cell from Green Hills Software, OKL4 from Open Kernel Labs, TRANGO Hypervisor from TRANGO Virtual Processors, RTS Hypervisor from Real-Time Systems or PikeOS from Sysgo, in case of the ---------Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can It does this by utilizing frequencies that are not used by a voice telephone A splitter - or microfilter - allows a single telephone connection to be used for both ADSL service and voice calls at the same Because phone lines vary in quality and were not originally engineered with DSL in mind, it can generally only be used over short distances, typically less than 3mi (5 km) [William Stallings' book]At the telephone exchange the line generally terminates at a DSLAM where another frequency splitter separates the voice band signal for the conventional phone Data carried by the ADSL is typically routed over the telephone company's data network and eventually reaches a conventional internet In the UK under British Telecom the data network in question is its ATM network which in turn sends it to its IP network IP CThe distinguishing characteristic of ADSL over other forms of DSL is that the volume of data flow is greater in one direction than the other, it is Providers usually market ADSL as a service for consumers to connect to the Internet in a relatively passive mode: able to use the higher speed direction for the "download" from the Internet but not needing to run servers that would require high speed in the other There are both technical and marketing reasons why ADSL is in many places the most common type offered to home On the technical side, there is likely to be more crosstalk from other circuits at the DSLAM end (where the wires from many local loops are close to each other) than at the customer Thus the upload signal is weakest at the noisiest part of the local loop, while the download signal is strongest at the noisiest part of the local It therefore makes technical sense to have the DSLAM transmit at a higher bit rate than does the modem on the customer Since the typical home user in fact does prefer a higher download speed, the telephone companies chose to make a virtue out of necessity, hence ADSL On the marketing side, limiting upload speeds limits the attractiveness of this service to business customers, often causing them to purchase higher cost Digital Signal 1 services In this fashion, it segments the digital communications market between business and home usersHow ADSL worksOn the wireCurrently, most ADSL communication is full Full duplex ADSL communication is usually achieved on a wire pair by either frequency division duplex (FDD), echo canceling duplex (ECD), or time division duplexing (TDD) FDM uses two separate frequency bands, referred to as the upstream and downstream The upstream band is used for communication from the end user to the telephone central The downstream band is used for communicating from the central office to the end With standard ADSL (annex A), the band from 875 kHz to 138 kHz is used for upstream communication, while 138 kHz – 1104 kHz is used for downstream Each of these is further divided into smaller frequency channels of 3125 kH During initial training, the ADSL modem tests which of the available channels have an acceptable signal-to-noise The distance from the telephone exchange, noise on the copper wire, or interference from AM radio stations may introduce errors on some By keeping the channels small, a high error rate on one frequency thus need not render the line unusable: the channel will not be used, merely resulting in reduced throughput on an otherwise functional ADSL Vendors may support usage of higher frequencies as a proprietary extension to the However, this requires matching vendor-supplied equipment on both ends of the line, and will likely result in crosstalk issues that affect other lines in the same There is a direct relationship between the number of channels available and the throughput capacity of the ADSL The exact data capacity per channel depends on the modulation method [edit] ModulationADSL initially existed in two flavours (similar to VDSL), namely CAP and DMT CAP was the de facto standard for ADSL deployments up until 1996, deployed in 90 percent of ADSL installs at the However, DMT was chosen for the first ITU-T ADSL standards, G1 and G2 (also called Gdmt and Glite respectively) Therefore all modern installations of ADSL are based on the DMT modulation Annexes J and M shift the upstream/downstream frequency split up to 276 kHz (from 138 kHz used in the commonly deployed annex A) in order to boost upstream Additionally, the "all-digital-loop" variants of ADSL2 and ADSL2+ (annexes I and J) support an extra 256 kbit/s of upstream if the bandwidth normally used for POTS voice calls is allocated for ADSL While the ADSL access utilizes the 1 MHz band, ADSL2+ utilizes the 2 MHz The downstream and upstream rates displayed are theoretical Note also that because Digital subscriber line access multiplexers and ADSL modems may have been implemented based on differing or incomplete standards some manufacturers may advertise different For example, Ericsson has several devices that support non-standard upstream speeds of up to 2 Mbit/s in ADSL2 and ADSL2+[edit] Installation issuesDue to the way it uses the frequency spectrum, ADSL deployment presents some It is necessary to install appropriate frequency filters at the customer's premises, to avoid interferences with the voice service, while at the same time taking care to keep a clean signal level for the ADSL In the early days of DSL, installation required a technician to visit the A splitter was installed near the demarcation point, from which a dedicated data line was This way, the DSL signal is separated earlier and is not attenuated inside the customer However, this procedure is costly, and also caused problems with customers complaining about having to wait for the technician to perform the As a result, many DSL vendors started offering a self-install option, in which they ship equipment and instructions to the Instead of separating the DSL signal at the demarcation point, the opposite is done: the DSL signal is "filtered off" at each phone outlet by use of a low pass filter, also known as This method does not require any rewiring inside the customer A side effect of the move to the self-install model is that the DSL signal can be degraded, especially if more than 5 voiceband devices are connected to the The DSL signal is now present on all telephone wiring in the building, causing attenuation and A way to circumvent this is to go back to the original model, and install one filter upstream from all telephone jacks in the building, except for the jack to which the DSL modem will be Since this requires wiring changes by the customer and may not work on some household telephone wiring, it is rarely It is usually much easier to install filters at each telephone jack that is in
空间遥感方法对压场 方向性估计。 一，导言 为外地的方向性品种的估计技术 研究文献[1] - [5]。因此，理论分析 之间的水听器阵列输出的关系 噪声场中[1]进行 - [5]。发达国家技术 是基于阵列波束输出或crossspectral 数组元素之间的产出[4] - [5矩阵]。那个 问题是在海洋领域的方向性估计使用， 水平线拖曳阵还讨论了文献[5] - [8]。最近，到达方向和领域的方向性问题 提出传感器阵列估计吸引了 新的兴趣[9] - [12]。结果表明，数组的议案 数组可以提高性能假设时间相干性 连续样本[10] - [11]。在[12]，波场 抽样方法，利用了线性关系 现场的噪音和多波束形成产出集合 各阵列方向提出。结果表明： 波场抽样（是）方法优于其他测试 方法。该算法通过实施递归 估算方法及其收敛性的独特的解决方案 是许诺的方针和一系列具体规定 波束研究方向。然而，一个正确的方法 阵列波束的方向和研究方向序列 选择仍然是一个悬而未决的问题。 该油田的方向性估计质量是决定 的角分辨率。较高的角分辨率 是，在远场的来源更准确的估计， 和更好的检测性能可以实现的。其中 在阵列信号处理的基本关系是： 的角分辨率是成正比的数目 数组的元素[13]。这种关系的愿望激励 更长的阵列，可以实现更高的分辨率。不幸地， 违反规定的实施和 安装限制，激励短阵列。而且， 较长的数组执行机动平台 如无人（无人潜航器），水下机器人，甚至可以 不可能的[14]。这些矛盾的追求激励 替代阵列信号处理方法。 通常，外地方向性被建模为有限集合 强远场窄带源和各向同性低功率 噪音[1]。在这项工作中，该字段的方向性模型 采用以下方式。首先，轴承角 空间均匀取样到大量的离散 角度。其次，假定醚的高能量 对应于远场强来源或低能量 对应于各向同性噪声的传感器接收 阵列从这些离散方位角每个。
Features • CSA/NRTL Approved • Used for non-intrusive configuration and calibration of SEC 2000 gas detectors• Calibrates, checks and correlates data from any SEC detector on the data highway• Bi-directional infrared communication when pointed at any SEC 2000 display board• Intrinsically safe menu driven device • Can communicate with SEC 1500, SEC 2000 and SEC DAIM devicesOperationThe SEC 2500 Hand Held Programmer transmits and receives infrared light from the front of the The infrared light is used to establish non-intrusive communication with any SEC 2000 that is equipped with a display When communicating with the SEC 2000, the SEC 2500 must be pointed directly at the display module of the SEC 2000 which can be up to 15 feet The Hand Held Programmer can communicate with any SEC 2000 gas detector on the same RS-485 network once infrared communication is Data exchange, using the infrared link, occurs at a rate of 300 The programmer has a socket at the bottom of the unit for connecting to a Data Communication Cable (P/N 147-1000C) The Data Communication Cable enables a hardwire communication connection to all SEC Once communication is established, the devices can be checked, calibrated and information can be correlated with a touch of the keypad located on the SEC 2500 Hand Held P The SEC 2500 Hand Held Programmer is certified for use in hazardous The SEC 4100 System Monitor is a multi-channel microprocessor based controller designed to monitor the gas and fire detection Each SEC 4100 System Monitor provides a digital display of each device and alarm level present at each Initiates alarms when any device senses a dangerous The SEC 4100 System Monitor has 2 sets of “Data A” and “Data B” terminals, labeled LAN X and LAN Y This allows the detectors to be connected in a compete The SEC 4100 will transfer communication between the LAN X and LAN Y highway when a communication fault is The SEC 4100 System Monitor can be used with SEC DAIM Modules to add other types of devices to the See SEC 4853 DAIM data sheet for further The SEC 4100 System Monitor can also be used in conjunction with the SEC 4850 Repeater, SEC 4851 Expansion Relay Controller, SEC 4852 High Density Display and SEC Supervision Plus software Other Products Available:Infrared Hydrocarbon Gas DetectorsExplosion Proof Gas DetectorsNon-Explosion Proof Gas Detectors4-20 mA Gas DetectorsData Logging/Graphics Software PackagesOptical UV/IR Flame DetectorsFire Suppression Aerosol GeneratorsPortable Automatic Fire Fighting SystemsHalotron SystemsTwin Agent UnitsDry Chemical Mobile and Stationary Units
高分不如高酬
出版信息书 名： 光纤通信技术作 者：柳春锋出版社：北京理工大学出版社出版时间：2010-1-1ISBN: 9787564011369开本：16开定价： 00元内容简介本书是为高等学校“光纤通信”课程而编写的基础教材。根据应用型本科人才培养的特点和要求，在内容体例上做了一些新的尝试，即“理论+应用+研究+实训”。在内容上，不仅介绍光纤、光缆、光器件等方面的基本概念、工作原理等基础理论，而且结合工程应用，介绍光纤通信系统工程方面的知识，如光缆选型、再生段计算、光缆敷设、光纤接续等，同时安排了研究项目和实训章节，以培养学生的专业素质，尤其是实践技能。全书共9章，主要包括光纤光缆结构及其特性、导光原理、光器件的结构原理及其特性、光端机的结构及其技术指标、再生段计算、光缆敷设、光纤接续等。各章除附有习题供读者练习外，还安排有研究项目。本书可供本科生和研究生使用，也可供从事光纤通信系统和网络研究、教学、规划、设计、使用、管理和维护的有关人员参考，还可作为培训教材使用。 出版信息书名：光纤通信技术作者：田国栋出版社：西安电子科技大学出版社出版时间：2008年09月ISBN：9787560621142开本：16开定价： 00 元内容简介《光纤通信技术》分三篇共九章，全面介绍了光纤通信基本知识（光纤通信概论，通信光纤与光缆，光通信器件）；系统阐述了光纤通信技术的应用（光纤传输体系与光网络，光纤传输设备与线路编码，光缆线路的设计、敷设与维护） ，重点讲授了光纤通信实践技能（光纤与光缆接续技术，光纤与光缆测试技术，光纤通信技能实训）。全书在内容选取上力求做到光纤通信理论的系统性、光纤通信技术的新颖性和光纤通信能力的实用性。图书目录第一篇 光纤通信基本知识第二篇 光纤通信技术的应用第三篇 光纤通信实践技能参考文献 书名：光纤通信技术（英文影印版）ISBN:703010131作者：Djafar KMynbaev/Lowell LScheiner出版社：科学出版社定价：60页数：750出版日期：2002-3-1版次：1开本：16开包装：平装简介：本书为国外高校电子信息类优秀教材（英文影印版）之一。本书通过大量的例子、图表以及实际问题，不但全面介绍了光纤通信系统中的基本技术，而且结合实际应用，介绍了光纤、系统以及网络中的最新技术和设备。本书主要内容有单模光纤基础、光缆的连接与测试、光源及光传输基础、接受器、光器件及光网络、光网络中的无源部件、开关及功能部件等。本书适用于通信、电子、计算机及相关专业本科生，也可供一般工程技术人员参考。目录：Chapter 1Introduction to Telecommunications and Fiber OpticsChapter 2Physics of Light:A Brief OverviewChapter 3Optical Fibers-BasicsChapter 4Optical Fibers-A Deeper LookChapter 5Singlemode Fibers-BasicsChapter 6Singlemode Fibers-A Deeper LookChapter 7Fabrication,Cabling,and InstallationChapter 8Fiber Cable Connectorization and TestingChapter 9Light Sources and Transmitters-BasicsChapter 10Light Sources and Transmitters-A Deeper LookChapter 11ReceiversChapter 12Components of Fiber-Optic NetworksChapter 13Passive Components,Switches,and Functional Modules of Fiber-Optic NetworksChapter 14An Introduction to Fiber-Optic NetworksChapter 15ConclusionAppendix AAppendix BAppendix CAppendix DIndex
这种去大学的校园网上查找最好，有些文献资料在学校是免费的，或者去书店，那就得买了
电子书-/thread-40682-1-html
百度啊KIRK_1500无线通信解决方案英文版
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文献综述反映当前某一领域中某分支学科或重要专题的历史现状、最新进展、学术见解和建议，它往往能反映出有关问题的新动态、新趋势、新水平、新原理和新技术等等。文献综述是针对某一研究领域分析和描述前人已经做了哪些工作，进展到何程度，要求对国内外相关研究的动态、前沿性问题做出较详细的综述，并提供参考文献。作者一般不在其中发表个人见解和建议，也不做任何评论，只是客观概括地反映事实。 一、何谓文献综述？ 文献综述是对某一学科、专业或专题的大量文献进行整理筛选、分析研究和综合提炼而成的一种学术论文，是高度浓缩的文献产品。根据其涉及的内容范围不同，综述可分为综合性综述和专题性综述两种类型。所谓综合性综述是以一个学科或专业为对象，而专题性综述则是以一个论题为对象的。学生毕业论文主要为专题性综述。 二、要求同学们学写综述的意义 通过搜集文献资料过程，可进一步熟悉文献的查找方法和资料的积累方法,在查找的过程中同时也扩大了知识面； 查找文献资料、写文献综述是科研选题的第一步，因此学习文献综述的撰写也是为今后科研活动打基础的过程； 通过综述的写作过程，能提高归纳、分析、综合能力，有利于独立工作能力和科研能力的提高。 三、文献资料的搜集 文献资料的搜集途径： 利用有关的检索工具（包括目录、文摘和索引等）搜集文献资料。 利用国际联机检索系统搜集文献资料。 利用原始文献（包括专业期刊、科技报告、专利文献、学位论文、会议文献、专著和标准等）搜集文献资料。 利用三次文献（包括综述、述评、百科全书、年鉴和手册等）搜集文献资料。 通过Interent网和光盘数据库搜集文献资料。 四、撰写文献综述时应注意以下问题 搜集文献应尽量全。掌握全面、大量的文献资料是写好综述的前提，否则，随便搜集一点资料就动手撰写是不可能写出好多综述的，甚至写出的文章根本不成为综述。 注意引用文献的代表性、可靠性和科学性。在搜集到的文献中可能出现观点雷同，有的文献在可靠性及科学性方面存在着差异，因此在引用文献时应注意选用代表性、可靠性和科学性较好的文献。 要围绕主题对文献的各种观点作比较分析，不要教科书式地将有关的理论和学派观点简要地汇总陈述一遍。 文献综述在逻辑上要合理，即做到由远而近先引用关系较远的文献，最后才是关联最密切的文献。 评述(特别是批评前人不足时)要引用原作者的原文(防止对原作者论点的误解)，不要贬低别人抬高自己，不能从二手材料来判定原作者的“错误”。 文献综述结果要说清前人工作的不足，衬托出作进一步研究的必要性和理论价值。 采用了文献中的观点和内容应注明来源，模型、图表、数据应注明出处，不要含糊不清。 文献综述最后要有简要总结，表明前人为该领域研究打下的工作基础。 所有提到的参考文献都应和所研究问题直接相关。 文献综述所用的文献，应主要选自学术期刊或学术会议 所引用的文献应是亲自读过的原著全文，不可只根据摘要即加以引用，更不能引用由文献引用的内容而并末见到被引用的原文，因为这往往是造成误解或曲解原意的重要原因，有时可给综述的科学价值造成不可弥补的损失。 五、文献综述的结构 文献综述主体部分的格式一般由前言、主题、结语三大部分组成，看起来和科技论文相似，但论述的重点不同。 这里是一篇文献综述正文部分的写作框架： 1．前言或简介（问题的提出，背景，动机等等）； 2．参考文献的来源及其主要的观点或学术流派、技术路线介绍； 3．各种观点的评价或各个学术流派、技术路线的发展趋势； 4．结语：值得关注的若干问题、目前该领域尚需探索的重大空白等等。 毕业论文的文献综述主要是为自己写作毕业论文提供文献方面的帮助和指导的，所以，只要把自己所作题目的相关文献找准、找全（这是编写参考文献题录阶段必须做好的工作），然后对这些文献中的观点、方法、原理、材料等等进行归纳和总结，形成文字就可以了，完全没有必要像做毕业论文那样，把自己的发明和创新全写上去，更不要象写教科书那样，从古到今面面俱到。总之，一篇好的文献综述，应有较完整的文献资料，有评论分析，并能准确地反映主题内容。 六、论文后参考文献表排写格式 每一参考文献条目的最后均以“。”结束。参考文献按在正文中出现的先后次序列表于文后，表上以“参考文献”居中排作为标识；参考文献的序号左顶格，并用数字加方括号表示，
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