车辆在交叉口燃油消耗的研究

行驶在城市道路上车辆的油耗主要受行程车速、停车率和延误等交通状况的影响，本文应用汽车行驶理论分析交通状况如何影响车辆油耗，并运用模拟技术通过对油耗试验结果和调查数据的分析建立了车辆耗油与交通状况的相关模型，同时，也讨论了需进一步研究的方向。     

Chain Vibration and Dynamic Stress in Three-Dimensional Multibody Tracked Vehicles

A three-dimensional computational finite element procedure for the vibration and dynamic stress analysis of the track link chains of off-road vehicles is presented in this paper. The numerical procedure developed in this investigation integrates classical constrained multibody dynamics methods with finite element capabilities. The nonlinear equations of motion of the three-dimensional tracked vehicle model in which the track link s are considered flexible bodies, are obtained using the floating frame of reference formulation. Three-dimensional contact force models are used to describe the interaction of the track chain links with the vehicle components and the ground. The dynamic equations of motion are first presented in terms of a coupled set of reference and elastic coordinates of the track links. Assuming that the structural flexibility of the track links does not have a significant effect on their overall rigid body motion as well as the vehicle dynamics, a partially linearized set of differential equations of motion of the track links is obtained. The equations associated with the rigid body motion are used to predict the generalized contact, inertia, and constraint forces associated with the deformation degrees of freedom of the track links. These forces are introduced to the track link flexibility equations which are used to calculate the deformations of the links resulting from the vehicle motion. A detailed three-dimensional finite element model of the track link is developed and utilized to predict the natural frequencies and mode shapes. The terms that represent the rigid body inertia, centrifugal and Coriolis forces in the equations of motion associated with the elastic coordinates of the track link are described in detail. A computational procedure for determining the generalized constraint forces associated with the elastic coordinates of the deformable chain links is presented. The finite element model is then used to determine the deformations of the track links resulting from the contact, inertia, and constraint forces. The results of the dynamic stress analysis of the track links are presented and the differences between these results and the results obtained by using the static stress analysis are demonstrated.     

基于OOP的任意组合条件检索模块的设计

本文介绍了一个使用ＯＯＰ技术对任意组合条件检索模块的设计思想，并在ＰＢ５环境中加以实现，该模块可被任何开发者在应用程序中调用，具有很强的通用性。     

电厂辅机设备运行管理系统研究与开发

针对目前电厂辅机设备运行管理系统存在的问题,开发了一套在线监视辅机运行状态的系统。该系统采用在线方法,实时监测辅机运行状况,使辅机设备运行管理与机组运行管理同步。通过分离后台计算程序与算法逻辑实现了算法的在线切换,使系统适应多种情况下辅机运行状况的判断。采用B/S模式的系统参数设定方式,简化了系统的管理和维护,同时又增加了灵活性。查询结果在Web浏览器上以表格形式显示,并且具有输出到Excel文件的功能。现场运行实践表明,该系统运行速度快、稳定性强,用户使用、维护方便,具有广阔的应用前景。     

遗传算法在直流传感器磁屏蔽体优化设计中的应用

应用遗传算法对直流传感器的磁屏蔽体进行优化设计,对遗传算法的适应度线性尺度变换作了改进.文中选取直流传感器的磁屏蔽效能为目标函数,给出了一个具体设计实例.优化后磁屏蔽效能增大了534,表明在磁屏蔽体优化设计中采用改进的遗传算法取得了良好效果.     

合成温度对LiFePO4电化学性能的影响

介绍了采用固相法制备锂离子电池正极材料LiFePO4的制备方法以及关于合成温度对材料结构和电化学性能的影响方面的研究结果。用X射线衍射(XRD)、扫描电镜(SEM)对材料的结构与形貌进行了表征;用恒流充放电实验、循环伏安对材料的电化学性能进行了研究,结果表明,700℃合成的LiFePO4电化学性能最佳,在0.2C的倍率下首次放电容量达到107.8mAh/g。     

Fe3(PO4)2固相法合成及其影响因素的研究

锂离子电池正极材料LiFePO4具有良好的发展前景。介绍了采用固相法合成Fe3P(O4)2的方法,并对实验现象进行了理论分析,用扫描电镜表征了实验产物的形貌。结果表明:Fe3P(O4)2的生成温度为200℃,但如果使反应进行完全,则需300℃以上;Fe3(PO4)2共有三种反应机理;温度和原始反应物的晶粒尺寸都会影响生成Fe3P(O42)晶粒的尺寸,温度越高,生成的Fe3P(O42)晶粒就越大,原始反应物的晶粒尺寸越小,生成的Fe3P(O4)2晶粒就越小。     

Boundary Layers in an Ocean Related System

In this article two regularizations of an hyperbolic model system derived from the primitive equations of the ocean (or the atmosphere) are presented. The two regularized systems converge to different limits as the regularization parameter converges to 0. Numerical approximations of these equations and numerical simulations are also presented     

Fuzzy-Logic Based Navigation of Underwater Vehicles

A fuzzy logic based general purpose modular control architecture is presented for underwater vehicle autonomous navigation, control and collision avoidance. Three levels of fuzzy controllers comprising the sensor fusion module, the collision avoidance module and the motion control module are derived and implemented. No assumption is made on the specific underwater vehicle type, on the amount of a priori knowledge of the 3-D undersea environment or on static and dynamic obstacle size and velocity. The derived controllers account for vehicle position accuracy and vertical stability in the presence of ocean currents and constraints imposed by the roll motion. The main advantage of the proposed navigation control architecture is its simplicity, modularity, expandability and applicability to any type of autonomous or semi-autonomous underwater vehicles. Extensive simulation studies are performed on the NPS Phoenix vehicle whose dynamics have been modified to account for roll stability.     

微波频率下乙酸乙酯皂化反应等效介电系数的实验研究

微波化学研究中的关键问题之一是对化学反应过程中的介电系数进行跟踪和测量.本文采用开槽同轴谐振探头首次测量了乙酸乙酯皂化反应对微波的反射系数,并用遗传算法获得了微波频率下该反应的等效介电系数.结果发现等效介电系数实部随温度的变化趋势符合L Onsager和Debye理论对极性混合溶液的描述;等效介电系数虚部因极化损耗和欧姆损耗随温度变化而相应变化;而等效介电系数实部随时间的变化与L Onsager极性混合溶液等效介电系数理论的描述相反.