PHD2-S型电源转换屏断相保护电路的改进

广东三茂铁路股份有限公司管内的三水西站、春湾站、春湾驼峰、阳春站使用的是PHD2-S型电源转换屏.2002年7～8月三水西站连续发生了5起因该转换屏电源输入熔断器熔断,导致信号恢复的故障,严重影响了行车安全.经查找,故障原因是引入电源屏的三相电源中其中一路高压三相电断相,而正在运用的电源转换屏又无法及时转换至另一路.因此,PHD2-S型电源转换屏断相保护电路存在不足.     

开好呼--法集装箱专列打通国际物流新通道

针对呼和浩特--法兰克福"如意号"国际集装箱专列的开行情况,分析和说明了开行的起因和背景,阐述了专列开行的重要意义,并对如何继续开好专列、进一步做好全方位国际物流服务进行探讨和分析,提出了具体改进措施.     

BES2型扼流变压器的调整使用

BES2型扼流变压器是大气隙铁芯带适配器的大容量扼流变压器。洛阳电务段管内侯月线扩能后，因牵引电流大幅增加，原有的400A普通扼流变压器已不能满足现场需要，因此在25Hz交流计数区段更换了BES2型扼流变压器，防止通过大牵引电流时可能产生的变压器磁饱和现象。同时，利用适配器克服大气隙对25Hz信号产生的大幅衰减。但更换后，区间频繁发生机车信号掉码或错误显示。为此，组织相关工程技术人员进行了深入分析处理。     

ZPW-2000A自动闭塞模拟试验

以成功应用于京沪线提速工程中的自动闭塞系统为例,介绍了ZPW-2000A的试验流程和模拟试验方法,并针对ZPW-2000A特有的小轨道探讨了模拟方案.     

胶新铁路路基实测沉降与预测分析

软弱土具有压缩性高、含水量大、强度低和透水性差等特点,在上部荷载长期作用下,必将产生一定的沉降,甚至发生于运营阶段,对铁路的运营质量造成危害。基于铁道部项目:胶新铁路路基沉降监测和预测研究,对不同的试验段进行了长达两年的监测,以给出规律性的结论。首先介绍了软弱土路基沉降及预测的研究概况,并对试验段进行了介绍。详细分析了该段路基的实测沉降及其变化规律,并对各断面在通车前后的累积沉降进行对比分析,得出重要结论。最后,对软弱土路基沉降变形预测进行了详细研究,结果与实测值较吻合。     

NT4-Ant-Shepherdin[79-87]融合基因重组载体的构建

目的设计构建携带NT4-Ant-Shepherdin[79-87]的cDNA融合基因的重组载体,为针对Survivin的靶向治疗奠定基础。方法应用非对称引物/模板法、PCR技术制备NT4-Ant-Shepherdin[79-87]cDNA片断,连接于pGEM-T-Easy载体,经克隆测序、酶切后与PBV220/NT4质粒连接;转化感受态细胞E.coliDH5α,亚克隆获得NT4-Ant-Shepherdin[79-87]融合基因。结果克隆出Ant-Shepherdin[79-87]基因,经酶切及测序证实结果正确;连接PBV220/NT4,经克隆、酶切,琼脂糖凝胶电泳证实获得321bp的NT4-Ant-Shepherdin[79-87]目的基因片断。结论通过分子生物学技术成功构建了携带NT4-Ant-Shepherdin[79-87]融合基因的重组载体,为进一步研究针对Survivin的靶向抗肿瘤作用奠定了基础。     

西安地区孕妇TORCH感染的血清学检测

自1994年3月～1996年3月，应用Elisa法，对1933例孕妇做了弓形体（TOX）、风疹病毒（RV）、巨细胞病毒（CMV）、单纯疤序病毒Ⅰ型和Ⅱ型（HSV1、HSV1）5种病原体血清特异性IgM、IgG抗体的检测。结果显示：孕妇血清中5种病原体特鼻性IgM抗体阳性率分别为3．41％、1．45％、5．54％、2．33％、1．86％；特异性IgG抗体阳性率分别为10.77％、88.50％、89.62％、82.09％、84.19％；孕妇TOX感染与其所在地区和职业有关；不同争期CMVIgM抗体阳性率有显著性差异；孕期CMV感染与异常妊娠可能有一定的关系。孕妇RV、HSV的易感因素有待进一步研究。孕妇TORCH感染的筛查对优生优育是非常有用的指标。     

Effect of orthogonal stiffeners on the stability of axially compressed steel jacking pipe

Load conditions for steel pipe-jacking are complex during the construction stage. The stability of steel jacking pipe has been an increasingly important problem as jacking forces, pipe diameters and jacking distances increase. However, there are no standards for pipe reinforcement, for prevention of buckling, or for remedying pipe that buckles when being jacked axially. Past experience suggests that stiffeners can effectively reinforce the structure. This study analyzes the effect of different stiffeners on the stability of steel jacking pipe under axial compression using finite element analysis. The results suggest that the stability of steel jacking pipe can be significantly improved by using orthogonal stiffeners, in terms of engineering costs and construction space inside the pipe. Based on current engineering practice, the application of orthogonal stiffeners is discussed. This study provides a useful reference for the design and construction of steel jacking pipe.     

Connected variable speed limits control and car-following control with vehicle-infrastructure communication to resolve stop-and-go waves

The vision of intelligent vehicles traveling in road networks has prompted numerous concepts to control future traffic flow, one of which is the in-vehicle actuation of traffic control commands. The key of this concept is using intelligent vehicles as actuators for traffic control systems. Under this concept, we design and test a control system that connects a traffic controller with in-vehicle controllers via vehicle-to-infrastructure communication. The link-level traffic controller regulates traffic speeds through variable speed limits (VSL) gantries to resolve stop-and-go waves, while intelligent vehicles control accelerations through vehicle propulsion and brake systems to optimize their local situations. It is assumed that each intelligent vehicle receives VSL commands from the traffic controller and uses them as variable parameters for the local vehicle controller. Feasibility and effectiveness of the connected control paradigm are tested with simulation on a two-lane freeway stretch with intelligent vehicles randomly distributed among human-driven vehicles. Simulation shows that the connected VSL and vehicle control system improves traffic efficiency and sustainability; that is, total time spent in the network and average fuel consumption rate are reduced compared to (uncontrolled and controlled) scenarios with 100% human drivers and to uncontrolled scenarios with the same intelligent vehicle penetration rates.     

回收粉在环氧沥青混凝土中的应用研究

大跨径钢桥面铺装用环氧沥青混凝土对集料有很高的要求。通过室内试验和实际生产验证。分析环氧沥青混凝土生产中使用回收粉的可行性，并结合具体工程给出使用量。