船用柴油机排气后处理技术进展

随着航运业的不断发展,船用柴油机排放污染物也已成为日趋严重的污染源。本文综述了船用柴油机排气中NOx、SOx．颗粒物、HC和COx等的后处理方法和技术,重点介绍NOx和SOx的净化技术．最后展望了船用柴油机排气控制技术的发展方向。     

城市轨道交通钢轨伤损分析

随着上海市轨道交通运营年限的不断增加,钢轨伤损已经成为影响线路安全性的一个重要因素.根据上海轨道交通1号线的钢轨损伤情况,对引起钢轨伤损的原因和伤损的数量进行统计分析.结果发现:上行和下行线路的伤损种类与分布大致相同;引起钢轨伤损的三个主要原因分别是焊接、轮轨作用以及钢轨的材质;钢轨裂纹主要发生在曲线地段.针对性地提出了关于减轻钢轨伤损的对策措施.     

我是传奇

正保时捷919 Hybrid性能之强可以肆意叱诧耐力赛场,攻城掠地,好不风光。开着它是一种什么样的感觉,保时捷运动赛车部门给了evo杂志一个极其宝贵的机会保时捷把这台919 Hybrid LMP1当做70周年纪念庆典的一部分就已经佐证了这台勒芒系列赛车拥有超越历史的特质:技术上大胆进取;功能性上极为稳定;最重要的,它令人发指地快。Veni, Vidi, Vici,我来,我见,我征服,919在各种厮杀角力之后一次又一次站在了耐力赛领奖台的顶端,它的成绩之好恐     

A study of polygonal wheel wear through a field test programme

High magnitude impact loads caused by polygonal wear of the wheels have been associated with in-service failures of structural components of high-speed railways, although the mechanisms leading to wheels’ polygonalisation is not yet fully understood. In this study, a long-term field test programme is undertaken and the data are analysed to gain better understanding of the growth in polygonal wear, and its characteristics and correlation with the axle box acceleration. The field measurements on a high-speed railway involved monitoring of wheels profiles between successive re-profiling of the wheels so as to identify the rate of growth of wear in addition to the axle box acceleration. The data suggested rapid growth in wheel wear, which could be characterised by polygonal wear of nearly 18th and 19th harmonic order. It is further shown that the magnitude of axle box acceleration increased considerably with increasing wear magnitude of the wheel.     

基于霍尔位置传感器的永磁同步电机方波启动问题研究

针对基于霍尔位置传感器的永磁同步电机启动不稳定的情况,本文提出了永磁同步电机180°方波电流启动,高速后切换到正弦波电流方法。以STM32F103为核心主控芯片,搭建硬件系统和软件算法,实验结果表明本控制策略能够实现满载启动和加速过程,电机运行平稳。     

深水起重铺管船横摇运动性能分析(英文)

For a large floating vessel in waves,radiation damping is not an accurate prediction of the degree of roll unlike other degrees of freedom motion.Therefore,to get the knowledge of roll motion performance of deepwater pipelay crane vessels and to keep the vessel working safety,the paper presents the relationship between a series of dimensionless roll damping coefficients and the roll response amplitude operator(RAO).By using two kinds of empirical data,the roll damping is estimated in the calculation flow.After getting the roll damping coefficient from the model test,a prediction of roll motion in regular waves is evaluated.According to the wave condition in the working region,short term statistics of roll motion are presented under different wave parameters.Moreover,the relationship between the maximal roll response level to peak spectral wave period and the roll damping coefficient is investigated.Results may provide some reference to design and improve this kind of vessel.     

低速船用柴油机整机吊具可靠性的有限元分析

船用低速柴油机的吊具受力复杂且不规则,传统设计通过简化模型计算其理论强度,与实际工况误差较大。文中利用有限元软件ANSYS分析,以6S42MC整机吊具为研究对象,采用三维软件PROE建立该吊具模型并对其进行有限元分析,根据分析所得的应力分布和形变情况,判断吊具的可靠性;通过改变吊具的结构尺寸,对减少吊具应力的方法进行探究;对吊具进行拓扑优化。分析结果表明,文中方法可以检验吊具的安全性,提高经济效益,同时为吊具的理论设计提供了依据。     

输电线路接地故障研究

利用R/S方法对输电线路弧光接地故障采样信号进行研究。分析弧光故障信号的频谱分布的规律及分形维数的特点。弧光故障采样信号的频谱分布在某种程度上定性地反映采样信号所对应的弧光接地故障的位置的变化,故障信号波形的分形维数是采样信号所对应的弧光接地故障位置的定量表达,故障信号波形的分形维数与其频谱分布具有很强的相关性。滤除基波后的故障信号波形的分形维数与线路的故障位置近似呈二次曲线的关系。弧光故障信号的频谱分布及R/S分析在输电线路弧光接地保护和弧光接地位置估计方面有很大的应用潜力。     

谈如何发挥好外派船长的作用

伴随着国际航运市场的迅速发展,劳务外派事业呈现出越来越广阔的发展前景。本文认为优良的思想品德、过硬的业务素质和优质的服务意识是影响劳务外派市场发展的关键所在。     

中国海事局海事调查官管理规定(试行)

第一章总则第一条为加强海事调查官队伍建设,提高海事调查的业务水平,保证海事调查处理工作质量,制定本规定。第二条本规定适用于海事系统从事水上交通事故调查处理工作的人员(以下称海事调查官)。第二条中华人民共和国海事局(交通部海事局)是负责实施本规定的主管机关。第二章