基于FPGA相关的毕设论文文献翻译

2009年国际信息和多媒体技术会议

基于FPGA的数字调频调制解调器

Indranil Hatai

电子和电气通信工程

印度理工学院kharagpur - 721302,印度indranilh@cse.iitkgp.ernet.in Indrajit Chakrabarti

电子和电气通信工程

印度理工学院kharagpur - 721302,印度indrajit@ece.iitkgp.ernet.in

摘要：本文介绍了一款高性能可编程数字调制解调器，这款调制解调器是基于FPGA实现的，主要用于软件无线电应用程序方面。该设计具有可重复编程、面积优化和低功耗等特点。这款调制器和解调器包含一个可直接压缩的数字合成器(DDS)，可生成的载波频率的自由动态范围超过了70分贝。解调器是在数字锁相环(DPLL)技术的基础上实现。同样地，DDS也被用来产生调制解调的载波信号。文中所提及的调频调制解调器已经在Virtex2Pro实验板上进行了实现和测试。所实现的调频调制解调器可以运行的最大频率达到103 MHz，而占用的门阵列资源等效到XC2VP-30系列FPGA开发板上仅有8K大小。

关键字：FM SDR FPGA DPLL DDS

I.简介

频率调制/解调技术被广泛应用于(PMR)标准下的DAB-T和私人移动无线电方面。传统的模拟调频主要是用来完成音频广播。但在模拟调频调制方案使用压控振荡器(VCO)时，困难出现了。任何音频广播中最主要考虑的问题是音频或声音的清晰度问题。由于线性的VCO工作在所要求的频率范围内时，性能出现了明显降低，使用VCO很难获得一个清晰的调频调制和解调信号。因此,基于数字技术实现调频调制方案的发展逐渐取代了传统的模拟调制。现在通过数字调频调制器架构，能够实现对任何音频声音都能具有优越的性能和良好的清晰度，这样的广播系统方案被广泛应用起来。

为了确保在整个频率范围内的线性，设计师通常采用DDS技术来替换VCO，因此这种控制也被称为数控振荡器（NCO）。目前，此项研究已经基于不同的数字调制解调器架构来开展了。而且其中的某些还突出了一些特色，如减少由于在进出DDS时的数码分辨率问题而引起的失真量化噪声的影响。他们中的一些人还讨论了有关区域优化和低功率消耗等性能方面的问题。就目前而言，基于FPGA载体，实现支持SDR的音频广播系统，同时兼具低功耗和低占有率特色的数字调制解调器已经成型。

基于不同调频架构体系的解调器的研究工作正不断将调频系统集成化，但是他们中的大多数是对模拟信号的处理，且处理精度有限。准确地识别当前信号频率与调频调制信号的中心频率微小的频率偏移是FM解调技术的关键问题。PLL 锁相环技术正是最常用的调频信号解调技术之一。锁相环可以跟踪信号相位和频

率的变化。同时它可以很容易的被集成，然而一旦它的线性度发生漂移，则会大幅降低整个VCO 系统的性能。幸运的是，数字锁相环技术可以提供一些克服模拟锁相环瓶颈问题的好方法。也有一些其他的技术，可以从信号同相的比率和通过正交组件来计算出频率。现代信息交互多呈现高速度、高数据率的传输和接收的特征。通过软件实现的数字解调器通常不能适应现代通信系统中这样的要求。另一种解决方案是在FPGA 中实现它,由于FPGA 的灵活性和模块化，低占有率，低功耗等特点，以及结合高速线性数字调频解调器使用的全数字锁相环路(ADPLL)技术，这种方案已经发展成为支持SDR 系统所优先选择的方案。

本文的组织结构如下:第二部分描述了调频调制器和调频解调器的原理和体系结构，第三部分和第四部分分别描述了用FPGA 实现的结果和与其他实现了的结果的比较，第五部分是结论。

II.调频调制器和调频解调器

调频调制器：

调频是角调制载波信号的一种，载波信号的瞬时频率变化与基带调制信号成如下线性关系：

()cos[22()]t

FM c c f S t A F t K m n dn ππ=+? (1)

其中c A 表示载波振幅，c F 表示载波频率，f K 表示频率偏移常数。

频率调制器的结构如图一所示：

调频调制器包括一个多路选择器、一个加法器和一个DDS 模块。多路选择器用来引入不同频率的载波。加法器用来将输入的基波信号的瞬时频率与载波频率相加，产生适应相位变化的不同频率。最后DDS 模块将这个信号作为输入并产生调频已调波信号。DDS 模块的结构在之后章节详述。所产生调频已调波信号的频谱如图二所示：

调频解调器：

早在19世纪70年代早期，数字锁相环作为解调器的想法就已经被提出了，这项发现的价值如同调频接收机一样卓越。完整的调频接收机的基本

构建模块如图三所示。调频接收器由四个基本部分组成：(1)相位侦测器(2)环路滤波器(3)直接数字频率合成器(4)FIR 滤波器。输入的已调波信号可以表示如下：

()sin(())i i i V t wt t θ=+

锁相环的反馈循环系统将迫使DDS 产生与输入信号相同频率的正弦信号： ()cos(())o i o V t wt t θ=+

通过常见的三角恒等式将这两个信号进行合成，结果作为相位侦测器的输出： ()[sin(()).cos(())]

[sin(2()())sin(()())]2d d i i i o d i i o i o V t K w t t w t t K w t t t t θθθθθθ=++=+++-

其中d K

是相位侦测器的增益。首项是高频频率分量。第二项是输入输出信号的相位差。已调波信号与载波信号的相位差产生所需的基带信号。

在设计锁相环时要注意的最重要的一点是，锁相环时一个闭环反馈系统。同时，较其他拥有同样数学特征方程的系统来讲，这是一款更通用的闭环反馈控制系统。

系统的传递函数如下：

22()() 1.93750.061610.00089Y s s s X s s s -+=-++

与一阶数字锁相环系统相比，二阶数字锁相环系统在提升环路传递速度和锁定范围方面性能更优越。因此此处选用二阶数字锁相环系统。

A 、相位侦测器

相位侦测器的功能是检测出ADC 输入的已调波信号频率与DDS 本振输出信号频率的频率差。它由一个寄存器和一个乘法器模块组成。乘法器是由改进的Booth 编码Wallace-tree 乘数结构来实现的。选用这种结构的原因是它能在N*M 位乘法运算中降低部分乘积数量到N/2。而且，当华莱士树节省加法器结构并行计算圆周率Pi 与圆周率Pi + 1时,我们可以预防Ardekani 符号扩展问题。华莱士树节省加法器结构如图四所示。

B 、环路滤波器

此处的环路滤波器是低通滤波器的一种，用来消除高频分量。图五显示了在调频接收机中一阶环路滤波器的模块组件。它将相位侦测器的输出信号和寄存器的输出乘上α=（1-1/16）=15/16=0.9375之后再相加。中间信号经过dtemp x 15/16 = dtemp x (1-1/16) = dtemp- (dtemp x 1/16) =dtemp-E 的运算，由此就可以只通过右移4位代替乘法器实现乘法操作。

C 、DDS

DDS 根据矫正的误差电压Vd(t),使它的输出频率在输入频率附近自由波动以保证DPLL 锁相环处于锁定状态。

常见生成复杂或设定的正弦波的方法是查表

法。通过查表法将合适的相位值送到数字积分器中来产生所要的输出波形。如图六所示，此处采用的也是基于查表法的DDS模块。DDS的频率浮动范围是1MHZ，它通过1024个点来离散一个周期的余弦信号。一个周期的信号可以分为四部分，第一部分仅需要256个点。所以只需要256*8位的ROM就可以代替1024*8位

的ROM来存储余弦信号的1024个点。通过这种方法，查表的深度和数据的宽

度都可以适当减小以适应最小70db的无杂散动态范围。这样输入相位会在累加器中累加并通过象限更迭。根据不同象限，多路复用器会选择存在余弦ROM表格中的数据，将第一第四象限中未补全的数值通过第二第三象限已补全的数值进行补全，如图六所示。

D、FIR滤波器

在接收机的最后环节，通过FIR滤波器将信号进行整形。此处选用的是16

级变频FIR滤波器，如图七所示。这个滤波器本质上是均值滤波器，因为其输出等于n级输入的平均值，其中n表示滤波器的级数。由于采用16位的数据采样，整个FIR滤波器的传输延时大大增加，因此此处选用可变频的FIR滤波器。这

里的系数是依然是1/16,在实际中实现缩小1/16只需右移4位即可，因此不再需要乘法器。

III.硬件实现细节

A、综合结果

通过Xilinx ISE 9.2i来编辑和实现电路。Xilinx XCV2vp30-7FF896设备用作FPGA实现载体，XST用作合成工具，XPower用作功率计算。通过仿真模拟信号并上电和掉电来计算功率消耗。调频调制器和解调器的综合结果已经列在表一中列出,表二是与通过其他方法基于FPGA实现的调频解调器比较的结果。

B、仿真结果

通过在Mentor graphics的FPGA Modelsim-Xe 6.3c版本中进行原件配置以及布线处理，我们做了一个仿真。将已存储的已调方波和三角波的数码流送到所设计的仿真器件，结果如图八所示。在仿真中，调试信号是39KHz的方波和三角波。载波频率是1MHz，调制指数是10。在两幅图中，信号从上到下依次是检波输出、已调波输出和输入基带信号。在仿真的初始阶段，检波输出信号出现自激振荡，当同步相位适应输入相位而收敛时，系统趋于稳定。

C、FPGA实现的结果

所设计的系统在Xilinx FPGA实验板上实现并用于Virtex-2 Pro大学。通过Xilinx Chipscope-Pro 9.2i来捕获解调输出信号分析所设计的FPGA电路的性能。在通过FPGA完成实验设计之后，用chipscope pro捕获了2048个输出样本，输出样本如图九所示。通过表格可以得出结论,设计的电路可以很容易地从调频输

入信号中解调出原来的有用信号。

IV.结果比较

通过优化调频接收机的基本组件,可以实现减少硬件的占用和改善工作性能。所提到的设计通过Mentor Graphics公司使用TSMC 350nm（典型）莱奥纳多光

谱2005b.24 Level 3来综合并收录于科技阅览室。当时常认为合成速度是设计电路最主要挑战。另一款调频接收机通过Mentor Graphics公司使用TSMC 350nm （快速）莱奥纳多光谱2004a.63来综合也同样收录于科技阅览室。从表III和表IV可以看出，本文中所设计的调频接收机在性能上要优于基于DPLL的调频解

调器。

V、总结

在调频接收机的基础上，通过VLSI实现的高性能数字锁相环路已经设计完成。因此，这样就可以满足个人无线通信应用在高频率信号处理领域的要求。当前所提及的这款设计功率仅为108.67mW，却可以实现100MHz频率信号的处理。电路只需7.8K的门阵列来完成，并且可以实现105MHz的最大工作频率。在这里可以得出结论, 下一代通信接收机电路将着重强调低功耗、最低硬件利用率同时保证最大的工作频率，文中所设计的高性能调频接收机可以很容易地适应下一代通信接收机的挑战。

鸣谢

作者要特别感谢新德里、通信与信息技术通过SMDP-II开发项目所提供的支持和奖励。

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Figure 8. Simulation result for square and traingular wave modulated and

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Figure 9. Chipscope result of the FM demodulator output (FMOUT)

毕设外文资料翻译.

理工学院 毕业设计外文资料翻译 专业：计算机科学与技术 姓名：马艳丽 学号： 12L0752218 外文出处：The Design and Implementation of 3D Electronic Map of Campus Based on WEBGIS 附件： 1.外文资料翻译译文；2.外文原文。

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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.

毕设外文文献翻译

xxxxxxxxx 毕业设计（论文）外文文献翻译 （本科学生用） 题目：Poduct Line Engineering: The State of the Practice 生产线工程：实践的形态 学生姓名：学号： 学部（系）: 专业年级: 指导教师：职称或学位： 2011年3月10日

外文文献翻译（译成中文1000字左右）： 【主要阅读文献不少于5篇，译文后附注文献信息，包括：作者、书名（或论文题目）、出版社（或刊物名称）、出版时间（或刊号）、页码。提供所译外文资料附件（印刷类含封面、封底、目录、翻译部分的复印件等，网站类的请附网址及原文】 Requirements engineering practices A precise requirements engineering process— a main driver for successful software development —is even more important for product line engineering. Usually, the product line’s scope addresses various domains simultaneously. This makes requirements engineering more complex. Furthermore, SPL development involves more tasks than single-product development. Many product line requirements are complex, interlinked, and divided into common and product-specific requirements. So, several requirements engineering practices are important specifically in SPL development: ? Domain identification and modeling, as well as commonalities and variations across product instances Separate specification and verification for platform and product requirements ? Management of integrating future requirements into the platform and products ? Identification, modeling, and management of requirement dependencies The first two practices are specific to SPL engineering. The latter two are common to software development but have much higher importance for SPLs. Issues with performing these additional activities can severely affect the product line’s long-term success. During the investigation, we found that most organizations today apply organizational and procedural measures to master these challenges. The applicability of more formal requirements engineering techniques and tools appeared rather limited, partly because such techniques are not yet designed to cope with product line evelopment’s inherent complexities. The investigation determined that the following three SPL requirements engineering practices were most important to SPL success. Domain analysis and domain description. Before starting SPL development, organizations should perform a thorough domain analysis. A well-understood domain is a prerequisite for defining a suitable scope for the product line. It’s the foundation for efficiently identifying and distinguishing platform and product requirements. Among the five participants in our investigation, three explicitly modeled the product line requirements. The others used experienced architects and domain experts to develop the SPL core assets without extensive requirements elicitation. Two organizations from the first group established a continuous requirements management that maintained links between product line and product instance requirements. The three other organizations managed their core assets’ evolution using change management procedures and versioning concepts. Their business did not force them to maintain more detailed links between the requirements on core assets and product instances. The impact of architectural decisions on requirements negotiations. A stable but flexible architecture is important for SPL development. However, focusing SPL evolution too much on architectural issues will lead to shallow or even incorrect specifications. It can cause core assets to ignore important SPL requirements so that the core assets lose relevance for SPL development. Organizations can avoid this problem by establishing clear responsibilities for requirements management in addition to architectural roles. The work group participants reported that a suitable organizational tool for balancing requirements and architecture is roundtable meetings in which requirements engineers,

关于力的外文文献翻译、中英文翻译、外文翻译

五、外文资料翻译 Stress and Strain 1.Introduction to Mechanics of Materials Mechanics of materials is a branch of applied mechanics that deals with the behavior of solid bodies subjected to various types of loading. It is a field of study that i s known by a variety of names, including “strength of materials” and “mechanics of deformable bodies”. The solid bodies considered in this book include axially-loaded bars, shafts, beams, and columns, as well as structures that are assemblies of these components. Usually the objective of our analysis will be the determination of the stresses, strains, and deformations produced by the loads; if these quantities can be found for all values of load up to the failure load, then we will have obtained a complete picture of the mechanics behavior of the body. Theoretical analyses and experimental results have equally important roles in the study of mechanics of materials . On many occasion we will make logical derivations to obtain formulas and equations for predicting mechanics behavior, but at the same time we must recognize that these formulas cannot be used in a realistic way unless certain properties of the been made in the laboratory. Also , many problems of importance in engineering cannot be handled efficiently by theoretical means, and experimental measurements become a practical necessity. The historical development of mechanics of materials is a fascinating blend of both theory and experiment, with experiments pointing the way to useful results in some instances and with theory doing so in others①. Such famous men as Leonardo da Vinci(1452-1519) and Galileo Galilei (1564-1642) made experiments to adequate to determine the strength of wires , bars , and beams , although they did not develop any adequate theo ries (by today’s standards ) to explain their test results . By contrast , the famous mathematician Leonhard Euler(1707-1783) developed the mathematical theory any of columns and calculated the critical load of a column in 1744 , long before any experimental evidence existed to show the significance of his results ②. Thus , Euler’s theoretical results remained unused for many years, although today they form the basis of column theory. The importance of combining theoretical derivations with experimentally determined properties of materials will be evident theoretical derivations with experimentally determined properties of materials will be evident as we proceed with

英文论文及中文翻译

International Journal of Minerals, Metallurgy and Materials Volume 17, Number 4, August 2010, Page 500 DOI: 10.1007/s12613-010-0348-y Corresponding author: Zhuan Li E-mail: li_zhuan@https://www.wendangku.net/doc/b81041389.html, ? University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg 2010 Preparation and properties of C/C-SiC brake composites fabricated by warm compacted-in situ reaction Zhuan Li, Peng Xiao, and Xiang Xiong State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China (Received: 12 August 2009; revised: 28 August 2009; accepted: 2 September 2009) Abstract: Carbon fibre reinforced carbon and silicon carbide dual matrix composites (C/C-SiC) were fabricated by the warm compacted-in situ reaction. The microstructure, mechanical properties, tribological properties, and wear mechanism of C/C-SiC composites at different brake speeds were investigated. The results indicate that the composites are composed of 58wt% C, 37wt% SiC, and 5wt% Si. The density and open porosity are 2.0 g·cm–3 and 10%, respectively. The C/C-SiC brake composites exhibit good mechanical properties. The flexural strength can reach up to 160 MPa, and the impact strength can reach 2.5 kJ·m–2. The C/C-SiC brake composites show excellent tribological performances. The friction coefficient is between 0.57 and 0.67 at the brake speeds from 8 to 24 m·s?1. The brake is stable, and the wear rate is less than 2.02×10?6 cm3·J?1. These results show that the C/C-SiC brake composites are the promising candidates for advanced brake and clutch systems. Keywords: C/C-SiC; ceramic matrix composites; tribological properties; microstructure [This work was financially supported by the National High-Tech Research and Development Program of China (No.2006AA03Z560) and the Graduate Degree Thesis Innovation Foundation of Central South University (No.2008yb019).] 温压-原位反应法制备C / C-SiC刹车复合材料的工艺和性能 李专，肖鹏，熊翔 粉末冶金国家重点实验室，中南大学，湖南长沙410083，中国（收稿日期：2009年8月12日修订：2009年8月28日;接受日期：2009年9月2日） 摘要：采用温压?原位反应法制备炭纤维增强炭和碳化硅双基体(C/C-SiC)复合材

毕业论文英文参考文献与译文

Inventory management Inventory Control On the so-called "inventory control", many people will interpret it as a "storage management", which is actually a big distortion. The traditional narrow view, mainly for warehouse inventory control of materials for inventory, data processing, storage, distribution, etc., through the implementation of anti-corrosion, temperature and humidity control means, to make the custody of the physical inventory to maintain optimum purposes. This is just a form of inventory control, or can be defined as the physical inventory control. How, then, from a broad perspective to understand inventory control? Inventory control should be related to the company's financial and operational objectives, in particular operating cash flow by optimizing the entire demand and supply chain management processes (DSCM), a reasonable set of ERP control strategy, and supported by appropriate information processing tools, tools to achieved in ensuring the timely delivery of the premise, as far as possible to reduce inventory levels, reducing inventory and obsolescence, the risk of devaluation. In this sense, the physical inventory control to achieve financial goals is just a means to control the entire inventory or just a necessary part; from the perspective of organizational functions, physical inventory control, warehouse management is mainly the responsibility of The broad inventory control is the demand and supply chain management, and the whole company's responsibility. Why until now many people's understanding of inventory control, limited physical inventory control? The following two reasons can not be ignored: First, our enterprises do not attach importance to inventory control. Especially those who benefit relatively good business, as long as there is money on the few people to consider the problem of inventory turnover. Inventory control is simply interpreted as warehouse management, unless the time to spend money, it may have been to see the inventory problem, and see the results are often very simple procurement to buy more, or did not do warehouse departments . Second, ERP misleading. Invoicing software is simple audacity to call it ERP, companies on their so-called ERP can reduce the number of inventory, inventory control, seems to rely on their small software can get. Even as SAP, BAAN ERP world, the field of

10kV小区供配电英文文献及中文翻译

在广州甚至广东的住宅小区电气设计中,一般都会涉及到小区的高低压供配电系统的设计.如10kV高压配电系统图,低压配电系统图等等图纸一大堆.然而在真正实施过程中,供电部门(尤其是供电公司指定的所谓电力设计小公司)根本将这些图纸作为一回事,按其电脑里原有的电子档图纸将数据稍作改动以及断路器按其所好换个厂家名称便美其名曰设计(可笑不?),拿出来的图纸根本无法满足电气设计的设计意图,致使严重存在以下问题:(也不知道是职业道德问题还是根本一窍不通) 1.跟原设计的电气系统货不对板,存在与低压开关柜后出线回路严重冲突,对实际施工造成严重阻碍,经常要求设计单位改动原有电气系统图才能满足它的要求(垄断的没话说). 2.对消防负荷和非消防负荷的供电(主要在高层建筑里)应严格分回路(从母线段)都不清楚,将消防负荷和非消防负荷按一个回路出线(尤其是将电梯和消防电梯,地下室的动力合在一起等等,有的甚至将楼顶消防风机和梯间照明合在一个回路,以一个表计量). 3.系统接地保护接地型式由原设计的TN-S系统竟曲解成"TN-S-C-S"系统(室内的还需要做TN-C,好玩吧?),严格的按照所谓的"三相四线制"再做重复接地来实施,导致后续施工中存在重复浪费资源以及安全隐患等等问题.. ............................(违反建筑电气设计规范等等问题实在不好意思一一例举,给那帮人留点混饭吃的面子算了) 总之吧,在通过图纸审查后的电气设计图纸在这帮人的眼里根本不知何物,经常是完工后的高低压供配电系统已是面目全非了,能有百分之五十的保留已经是谢天谢地了. 所以.我觉得:住宅建筑电气设计,让供电部门走!大不了留点位置,让他供几个必需回路的电,爱怎么折腾让他自个怎么折腾去.. Guangzhou, Guangdong, even in the electrical design of residential quarters, generally involving high-low cell power supply system design. 10kV power distribution systems, such as maps, drawings, etc. low-voltage distribution system map a lot. But in the real implementation of the process, the power sector (especially the so-called power supply design company appointed a small company) did these drawings for one thing, according to computer drawings of the original electronic file data to make a little change, and circuit breakers by their the name of another manufacturer will be sounding good design (ridiculously?), drawing out the design simply can not meet the electrical design intent, resulting in a serious following problems: (do not know or not know nothing about ethical issues) 1. With the original design of the electrical system not meeting board, the existence and low voltage switchgear circuit after qualifying serious conflicts seriously hinder the actual construction, often require changes to the original design unit plans to meet its electrical system requirements (monopoly impress ). 2. On the fire load and fire load of non-supply (mainly in high-rise building in) should be strictly sub-loop (from the bus segment) are not clear, the fire load and fire load of non-qualifying press of a circuit (especially the elevator and fire elevator, basement, etc.

【英文文献及翻译】中国高速铁路China High-Speed Railway

China High-Speed Railway As the economic grow, intercity travel demand has increased dramatically in the Greater China Area. Traditional railways can hardly satisfy the passenger and freight travel demand, high speed rail is hence proposed and constructed after 1990s. This study aims to integrate current development of both rail-based and Maglev high speed trains in this area. From 1997, Taiwan kicked-off its high speed rail construction by importing the technology of Japanese Shinkansen. The Taiwan High Speed Rail is a 15-billion US dollars project. To save the cost of construction and management, the BOT model was applied. Though not totally satisfied, this project is still successful and ready to operate in the 4th quarter of 2007. China is preparing its high speed rail services by upgrading current networks. The capacity and operating speed are all increased after 5-times system upgrade. The 6th upgrade will be initiated in 2006. By then, trains will run at a speed of 200km/h in a total distance of 1,400km in 7 different routes. From the white paper published by the Ministry of Railway in China, there will be totally 8 rail-based High Speed Train services. Four of them are North-South bound, and four of them are East-West bound. 5 of the 8 High Speed Rails are now under construction, the first line will be finished in 2009, and the 2nd one will be in 2010. By 2020, there will be totally 12,000 kilometers high speed rail services in China. The 250 billion US dollars construction cost still leaves some uncertainties for all these projects. Finally, the future of the Maglev system in China is not so bright as rail-based. Shanghai airport line could be the first, also the last Maglev project in China if the approved Shanghai-Hangzhou line cannot raise enough 4.4 billion dollars to build it. Steel rail composition Steel rail is composed of iron, carbon, manganese, and silicon, and contains impurities such as phosphorous, sulphur, gases, and slag. The proportions of these substances may be altered to achieve different properties, such as increased resistance to wear on curves. The standard configuration for North American rail resembles an upside down T. The three parts of T-rail are called the base, web, and head. The flat base enabled such rail to be spiked directly to wooden crossties; later, rail was placed on the now-standard steel tie plate. While the proportions and precise shape of rail are subject to constant analysis and refinement, the basic T-section has been standard since the mid-19th century. Weight