多类型信息下的网络交通流演化模型

交通信息发布机构提供描述信息和规范信息给不同的出行者，描述信息接收者依据信息和经验更新路径行程时间认知，根据认知选择路径；规范信息接收者仅根据经验更新认知.规范信息遵从者选择推荐路径，非遵从者依据认知选择路径.两类信息遵从率都取决于信息准确度.依据非线性动力学理论分析了模型性质，研究表明，模型不动点存在但是不一定唯一，不动点状态与信息混合使用情况有关.数值试验结果表明，模型不动点与随机用户均衡点不同，以恰当比例混合使用两类信息可提高交通流稳定性.     

横甩研究概况与发展方向

介绍了非线性动力学理论在船舶横甩研究中的应用，总结了近年来横甩研究的主要方法和结论，最后指出了横甩问题尚需深入研究的几个方面。     

柴油机主副连杆机构动力分析

认为主、副连杆是两个独立运动的刚体，它们通过关节销连接起来．通过坐标转换关系，研究主副连杆机构平面运动规律，导出了主副活塞运动的速度、加速度以及主、副连杆不动、摆动的加速度、角加速度．基于刚体平面运动理论，对V型柴油机主副连杆机构进行动力学分新，给出了计算公式，便于编程计算。     

电机悬挂方式对LIM地铁系统动力特性的影响研究

研究目的：研究直线电机地铁在不同电机悬挂方式下的气隙变化规律及车辆、轨道的动力响应特性，并将二者进行比较。研究方法：应用车辆轨道耦合动力学理论，分别建立不同悬挂方式下的系统模型并编制相应的仿真程序，通过在轨道局部加入谐波型余弦不平顺激励对系统的动力特性进行分析。研究结果：2种悬挂方式对系统的各向加速度和轮轨力的影响差别较小，而气隙变化呈现明显不同的规律。研究结论：直线电机采用架悬式悬挂时，要严格控制幅值大于5．5mm的长波不平顺，防止电机和反力板之问的刮蹭；而当采用抱轴式悬挂时，要注意控制大幅值的短波不平顺出现，防止气隙过大，影响电机效率。     

Biologically induced modification of seawater viscosity in the Eastern English Channel during a Phaeocystis globosa spring bloom

To identify the potential relationship between Pheaocystis globosa bloom conditions and seawater properties, a hydrobiological survey was performed in the inshore waters of the Eastern English Channel over the course of the phytoplankton spring bloom. Chlorophyll concentration, auto- and hetero/mixotrophic composition of protists and standing stock, and seawater viscosity were measured weekly from March to June 2004. The decline of the bloom is characterized by a massive foam formation in the turbulent surf zone. Before foam formation, seawater viscosity significantly increased, showing a significant positive correlation with chlorophyll concentration. In contrast, after foam formation this correlation was negative, seawater viscosity kept increasing despite a sharp decrease in chlorophyll concentrations. No significant correlation has been found between seawater viscosity and the composition of the phytoplankton assemblages observed during the survey. However, significant positive correlations have been found between seawater viscosity and both the size and the abundance of P. globosa colonies. From the correlation patterns observed between chlorophyll concentration and seawater viscosity, we suggest that the rheological properties of seawater are mainly driven by extracellular materials associated with colony formation and maintenance rather than by cell composition and standing stock.     

中间轴驱动装置固定对弹性悬挂式机车动力学性能的影响

为防止弹性悬挂式机车中间轴驱动装置横向位移过大,发生碰撞,提出了端轴驱动装置弹性悬挂、中间轴驱动装置固定连接的方式。利用多体动力学软件SIMPACK建立整车动力学模型,对比分析驱动装置悬挂方式对机车动力学性能的影响,认为采用这种悬挂方式是合理可行的。     

基于虚拟样机技术的高速弓网系统研究

虚拟样机技术的核心是参数化、可视化设计和综合性能分析。本文结合我国250km/h高速受电弓设计,应用虚拟样机技术,对铁路接触网-受电弓系统进行系统研究。在进行受电弓可视化三维实体设计的基础上,应用多体系统动力学软件SIMPACK和有限元计算软件ANSYS,进行了受电弓的几何分析及受电弓零部件的强度和刚度校核,计算了接触网振动模态和自振频率;运用结构子结构方法,建立了受电弓-接触网耦合系统模型,计算了不同模拟运行速度下的弓网振动和接触压力响应,以及机车运行振动对受流的影响;最后为了考核接触网的疲劳可靠性,进行了在运行条件下的接触网动应力研究。     

Multiphysic modelling of railway vehicles equipped with pneumatic suspensions

This article presents a multidisciplinary approach of railway pneumatic suspension modelling: both multibody and pneumatic aspects are taken into account. The work aims at obtaining a realistic model of the secondary suspension and coupling it with a multibody model of a train. Various components of the pneumatic circuit such as bellows, tanks, pipes and valves are taken into account. The article focuses on the bellow-pipe-tank subsystem for which several modelling approaches are presented and compared. Differences between differential and algebraic models are highlighted, and an application-dependent choice between them is suggested. A complete model of the pneumatic circuit is then obtained and coupled with a multibody model of the train. As a result, the behaviour of a suburban train equipped with a pneumatic secondary suspension is analysed, in particular undesired oscillating motions which affect the comfort. Topological modifications and improvements of the suspension are also investigated and discussed.     

B_0-B_0机车转向架直线运行横向轮/轨力和蛇行稳定性的理论研究(上)

本文根据轮/轨蠕滑理论提供了计算和分析B_0—B_0机车转向架直线运行横向轮/轨力的方法,并以SS4型电力机车作为验证实例,理论计算和实际测试的结果相接近。作者采用这种方法对轮/轨力进行可靠的分析,旨在论证我国现有电力机车转向架蛇行稳定性所要求的最佳轮对定位刚度。本文论证结果符合于作者在文献[1]中提出的轮对定位新方案,它可适用于最大运行速度为100km/h的现有SS型电力机车。     

无公用轴独立旋转车轮转向架直线横向动力学研究

无公用轴独立旋转车轮转向架的车辆不仅左右车轮的旋转自由度独立,而且两轮的横移和摇头也解耦。文章通过建立无公用轴独立旋转车轮转向架车辆在直线上的横向动力学客车模型,模拟实际线路,利用新型数值快速积分法进行动态仿真,得出无公用轴独立旋转车轮转向架车辆的动态响应值,并与具有相同悬挂参数的传统客车进行比较。