牵引变压器的轻量化

ABB公司研制出“Pett”电力电子牵引变压器样机。目前，该样机已安装到电力机车上进行测试。这种轻型变压器的研发目标是：为空间和重量方面要求苛刻的电动车组开发一种结构紧凑、重量轻、功能强大、节能效率高的变流器。     

Overseas Investment:The Resources Needs To Lead The Financial And Manufacturing Industries

American subprime crisis has evolved into a global financial crisis, dragging the entire economy, hitting the fictitious economy the most.Under such a situation,the world's investment environment changes inevitably as a result. In talking about the influence of the financial crisis upon China,the most immediate consequence     

SPWM差值二次逼近算法

在大功率逆变器的实时控制中，如何快速准确地计算出ＳＰＷＭ交点是一个关键问题。文中介绍了ＳＰＷＭ差值二次逼近算法的原理，推导了各种ＳＰＷＭ调试方式下的计算公式，并分析了算法误差及谐波分析，给出了ＳＰＷＭ同步调试方式下该算法实现的程序框图。该算法在４０００ｋＷ交直交电力机车油冷变流机组地面试验系统中得到验证，并取得了良好效果。     

采用光纤接口的机车总线网卡设计

介绍了出口伊朗的ＴＭ１型电力机车微机控制系统的牵引控制单元（ＴＣＵ）与中央控制单元（ＣＣＵ）之间信息交换的多功能机车总线（ＭＶＢ）网卡硬件设计及其工作原理，阐述了ＭＶＢ网卡硬件电路的在个主要部分：与ＴＣＵ的接口部分、主控制器部分和光纤接口部分。这种网卡设计电路简单，提高了信息交换的可靠性，加快了信息传输速度。经功能调试表明，网卡达到了技术要求。     

小功率变频调速器的设计思路

结合实际，着重对电压波形改善的技术以及脉冲生成电路和脉冲触发电路做了定性分析。     

FLICKER INDEX METHOD FOR EVALUATING FLICKER IN COLOR PDPs

Motionartifacts ,thenumberofvisiblegraylevelsandlargeareaflickerarethemainissuesaf fectingimagequalityincolorPDPs[1] .Thehighlyflickeringimagescausemoreseverefatigueofbrainthanofeyes[2 ] .Inordertoreduceflickereffectively ,theframerateand/orhorizontalfrequencyaredoubledtopreventlargeareaflickerinsuchCRTtelevisionsets.However ,itisundesirabletoadoptframerateconversiontechnologyincolorPDPswhenaddressdisplayseparated (ADS)drivingmethodisused[1] .Athigherframerate ,lesstimeisavailableperframe…     

SET OPERATOR-BASED METHOD OF DENOISING MEDICAL VOLUME DATA

Ｖｏｌｕｍｅｒｅｎｄｅｒｉｎｇ[1,2 ] ｉｓａｐｏｗｅｒｆｕｌｖｉｓｕａｌｉｚａ ｔｉｏｎｔｏｏｌｅｓｐｅｃｉａｌｌｙｕｓｅｆｕｌｉｎｍｅｄｉｃａｌａｐｐｌｉｃａｔｉｏｎｓ .Ｉｔｅｎａｂｌｅｓｔｈｅｄｉｓｐｌａｙｏｆａｎａｔｏｍｉｃａｌｓｔｒｕｃｔｕｒｅｓｉｎａｓｐａ ｔｉａｌｃｏｎｔｅｘｔｗｉｔｈｔｈｅｓｕｒｒｏｕｎｄｉｎｇａｎａｔｏｍｙ ,ｄｉｒｅｃｔｌｙｆｒｏｍａｆｉｅｌｄｏｆｉｍａｇｅｄａｔａ .Ｔｈｉｓｔｅｃｈｎｉｑｕｅｈａｓｂｅｅｎａｐｐｌｉｅｄａｔｓｅｖｅｒａｌａｎａｔｏｍｉｃｓｉｔｅｓａ…     

用空间分析方法计算圆曲线上斜交涵洞长度

以往的涵洞长度计算方法都是从平面上着手分析、考虑并找出其计算公式的。但由于影响涵洞长度的因素较多,并且各因素间相互制约,使得有的方法公式推导过程较为繁琐,有的计算结果误差偏大。为此,本文利用空间解析方法,使涵长计算公式的推导过程极为简便、直观,进而找出可能情况下的涵洞长度准确表达式,并给出计算实例,以便在设计中参考使用。     

Analysis of a Passive Sequential Hydraulic Damper for Vehicle Suspension

Vibration isolation characteristics of a sequential hydraulic damper, employing external pressure relief valves, are investigated via analytical means. The sequential hydraulic damper is modelled as a nonlinear dynamical system incorporating nonlinearities due to orifice flows, gas spring and pressure relief mechanisms. The damping characteristics of the sequential hydraulic damper, are compared to those of a constant orifice and a semi-active sequential damper, and discussed in view of their vibration isolation performance. It is established that the performance characteristics of the sequential hydraulic damper are similar to that of a semi-active sequential damper. A tuning methodology to achieve appropriate control of the resonant peak and effective vibration isolation is proposed. The shock and vibration isolation performance of the vehicle model employing a sequential damper are evaluated and compared to those of the vehicle model employing a constant orifice hydraulic damper. It is concluded that the vehicle ride performance can be improved considerably using an adequately tuned sequential damper.     

铁路新型快餐饭盒降解性能及评价方法的研究

在国内首次对新型快餐饭盒的光、生物降解性能及评价方法进行了比较全面、系统、深入的研究。第一次提出以光辐射累积能量（自然光源为３００ＭＪ／ｍ２，氙灯光源为１６．８００ＭＪ／ｍ２）取代目前以时间（ｈ、ｄ）为光降解试验控制参数，及以重均分子量下降率（７０％）作为光降解性能的定量评价参数。从而改善了原试验结果准确性、可比性、重现性差的不足；明显缩短了试验周期，降低了成本。还证实光降解到一定阶段时可加速生物降解的进程。