对《三相异步电动机缺相保护电路的改进》一文探讨

《铁道通信信号》期刊在2004年第2期刊登的《三相异步电动机缺相保护电路的改进》一文，介绍的方法简单、易行，很贴合实际，但在应用过程中发现经常出现拒动现象。经过分析认为该电路（如图1）有几点值得商榷。     

从海上搜救的角度谈如何应对重大海上突发事件

重大海上突发事件需要国家搜救服务机构迅速作出反应，组织大规模搜救行动，救助人命并化解严重危害海洋生态环境的污染险情。引发重大海上突发事件的原因有很多，除海上运输可能造成重大海难事故外，其他行业如民航运输、海洋石油、海洋养殖捕捞都是重大海上突发事件潜在的事故源。     

非饱和地基的强夯加固与夯沉变形相关性探讨

强夯法在工程中广泛应用,但目前对非饱和地基的应用性研究相对较少,实际工程应用中仍以经验为主,不能全面的揭示夯后地基土工程性质改善的原因。根据勘察和试验数据资料,通过地基土夯后测试数据与夯前数据的对比,揭示出该地区地基土经强夯加固后其工程性质得以改良的某些原因,对其适用提供了依据,具有一定的工程实际意义。     

综合自动化在牵引供电系统中的创新性应用

以邯郸供电段辖内的镇内变电所综合自动化改造为例,介绍了一种适用于电气化铁道的综合自动化系统的构成方案。针对高速区段牵引变电所运行中保护、控制部分存在的问题,详细阐述了测控装置创新性解决方案。     

AGV激光定位系统角度测量电路的设计

从工程应用的角度讨论激光定位系统角度测量电路的结构及与计算机的接口电路的设计,并以自行研究的AGV激光定位系统角度测量电路为例,详述各功能电路的设计方法及一些实际问题的具体解决办法.     

Train–track–bridge dynamic interaction: a state-of-the-art review

ABSTRACT

Train–track–bridge dynamic interaction is a fundamental concern in the field of railway engineering, which plays an extremely important role in the optimal design of railway bridges, especially in high-speed railways and heavy-haul railways. This paper systematically presents a state-of-the-art review of train–track–bridge dynamic interaction. The evolution process of train–bridge dynamic interaction model is described briefly, from the simplest moving constant force model to the sophisticated train–track–bridge dynamic interaction model (TTBDIM). The modelling methodology of the key elements in the TTBDIM is systematically reviewed, including the train, the track, the bridge, the wheel–rail contact, the track–bridge interaction, the system excitation and the solution algorithm. The significance of detailed track modelling in the whole system is highlighted. The experimental research and filed test focusing on modelling validation, safety assessment and long-term performance investigation of the train–track–bridge system are briefly presented. The practical applications of train–track–bridge dynamic interaction theory are comprehensively discussed in terms of the system dynamic performance evaluation, the system safety assessment and train-induced environmental vibration and noise prediction. The guidance is provided on further improvement of the train–track–bridge dynamic interaction model and the challenging research topics in the future.     

“摩托车和轻便摩托车操纵件、指示器及信号装置的图形符号”标准浅析

<正>GB 15365—2008《摩托车和轻便摩托车操纵件、指示器及信号装置的标志》标准,等效采用ISO/DIS6727:2001《道路车辆摩托车操纵件、指示器及信号装置的标志》标准,摩托车部分的技术内容与其相同。GB 15365—2008标准2008年12月31日发布,对新认证车型,2009年9月1日起实施;对在生产车型,2010年1月1日实施。本文主要讨论GB 15365—2008与GB 15365—1994两标准的主要区别,GB 15365—2008与欧标2009/80/EC在技术内容上的主要差异,以及随着GB     

Assessing methods for comparing emissions from gasoline and diesel light-duty vehicles based on microscale measurements

This paper assess whether a real-world second-by-second methodology that integrates vehicle activity and emissions rates for light-duty gasoline vehicles can be extended to diesel vehicles. Secondly it compares fuel use and emission rates between gasoline and diesel light-duty vehicles. To evaluate the methodology, real-world field data from two light-duty diesel vehicles are used. Vehicle specific power, a function of vehicle speed, acceleration, and road grade, is evaluated with respect to ability to explain variation in emissions rates. Vehicle specific power has been used previously to define activity-based modes and to quantify variation in fuel use and emission rates of gasoline vehicles taking into account idle, acceleration, cruise, and deceleration. The fuel use and emission rates for light-duty diesel vehicles can also be explained using vehicle specific power -based modes. Thus, the methodology enables direct comparisons for different vehicle fuels and technologies. Furthermore, the method can be used to estimate average fuel use and emission rates for a wide variety of driving cycles.     

TBM洞外狭小场地快速组装调试技术

中天山隧道洞外TBM组装场地异常狭小，在未经过工厂组装的情况下，因地制宜，采取边组装、边步进、边调试的快速组装方法，顺利完成组装调试及步进工作。     

32例慢性前列腺炎患者的尿流动力学分析

目的　总结慢性前列腺炎患者可能存在的下尿路症状 ,并结合尿流动力学分析各类症状出现的深层次原因。方法　对 32例慢性前列腺炎患者的尿流率、膀胱压力容积、压力 流率、前列腺压和肌电图进行综合性回顾分析 ,并就慢性细菌性和非细菌性前列腺炎组的尿流动力学变化作了比较。结果　 40 6 %的患者存在不稳定性膀胱 ,34 4%的患者有逼尿肌反射亢进 ,46 9%的患者有膀胱出口处梗阻 ,另有 6 8 7%的患者存在逼尿肌 外括约肌协同失调 ;而慢性细菌性和非细菌性前列腺炎组的尿流动力学差异并无显著性。结论　慢性前列腺炎患者出现不同程度的下尿路症状可能与前列腺或盆腔内局部因素诱发的不稳定性膀胱、逼尿肌反射亢进、膀胱出口处梗阻和逼尿肌 外括约肌协同失调有关。认识并解除这些相关因素有助于提高慢性前列腺炎的综合疗效。