一般边界条件下矩形薄板振动声辐射特性分析

基于改进傅立叶级数方法,将矩形板振型函数表示为包含正弦三角级数的改进傅立叶级数,从而有效地克服结构在边界处存在的不连续性,建立了一般边界条件下矩形薄板结构振动声辐射的分析方法,并对薄板结构的振动声辐射特性进行了研究。文中还建立了薄板结构的位移容许函数,然后基于最小势能原理求解了系统的Lagrange函数,最后利用Rayleigh-Ritz法对方程求解从而获得薄板自由振动的模态信息;在此基础上,基于Rayleigh积分公式推导出了薄板振动、辐射声压和声功率的表达式,研究了结构特性参数及边界条件对薄板振动声辐射的影响,通过有限元软件和参考文献的比对分析,验证了改进方法的正确性和有效性。     

基于损失函数法的船舶操纵水动力导数灵敏度分析

船舶操纵水动力导数的灵敏度分析是简化和重建船舶操纵运动数学模型的主要手段。本文使用平方损失函数方法对船舶操纵水动力导数进行灵敏度分析,并基于灵敏度分析结果对Mariner船的操纵运动数学模型进行简化。通过基于简化模型和原始数学模型的操纵运动仿真对比,验证了基于损失函数法的船舶操纵水动力导数灵敏度分析方法的有效性。     

Time-domain strip method with memory-effect function considering the body nonlinearity of ships in large waves

A time-domain strip method with memory-effect function considering body nonlinearity is presented. In small waves, results from conventional linear strip theory and the present method for a modified Wigley model were compared with the results of linear theories and with experiments, and they were found to be in good agreement. In large waves, a 716 TEU containership was used to compare time histories of motions and vertical bending moments calculated using the present method with experimental results. The time histories of motion were not strongly distorted, but those of the vertical bending moments were extremely distorted, especially for the fore part, and were far from sinusoidal signals. The time histories of the calculations and the experimental results were found to be, qualitatively and quantitatively, in good agreement. A post-Panamax containership was also used as an example of an up-to-date large bow-flare ship, and the calculated results were also found to be in good agreement with the experimental results.     

基于开放通信协议的城市智能交通信号控制系统测试实践

为了保证城市智能交通信号控制系统建设的质量，需要引进相应的测试手段。本文主要阐述基于开放通信协议（NTCIP）的城市智能交通信号控制系统测试实践。使用测试理论的V模型理论，对厂商提交的产品和系统进行相关测试，以保证系统建设质量。测试内容主要包括功能测试、协议符合性测试和系统性能测试。     

On the effect of unsupported sleepers on the dynamic behaviour of a railway track

The effect of unsupported sleepers on the dynamic behaviour of a railway track is studied based on vehicle–track dynamic interaction theory, using a model of the track as a Timoshenko beam supported on a periodic elastic foundation. Considering the vehicle's running speed and the number of unsupported sleepers, the track dynamic characteristics are investigated and verified in the time and frequency domains by experiments on a 1:5 scale model wheel–rail test rig. The results show that when hanging sleepers are present, leading to a discontinuous and irregular track support, additional wheel–rail interaction forces are generated. These forces increase as further sleepers become unsupported and as the vehicle's running speed increases. The adjacent supports experience increased dynamic forces which will lead to further deterioration of track quality and the formation of long wavelength track irregularities, which worsen the vehicles’ running stability and riding comfort. Stationary transfer functions measurements of the dynamic behaviour of the track are also presented to support the findings.     

青藏线工程生活供应客车

为适应青藏线工程生活供应的需要,将22型硬座车改造为工程生活供应客车。对改造后的工程生活供应客车的功能、平面布置及结构改造内容进行了介绍。     

充分发挥民营物流企业在战争动员中的作用

首先分析了民营物流企业的现状，阐述了民营物流企业在战争动员中的作用，如缓解征用民力资源的矛盾、协调动员体制和地方发展经济不顺畅问题、有利于民营物流企业经营管理改善和发展等，并对如何发挥民营物流企业在战争动员中的作用，提出了一些措施。     

一类非自治二阶系统的周期解

研究了一类非自治二阶系统周期解的存在性。给出了一些新的存在条件,在这些条件下,使用极小作用原理,得到了4个新的存在性定理。     

基于多媒体技术的指挥调度系统关键技术研究

论证多媒体调度系统研制的可行性,分析多媒体调度系统的设计与实现体系结构、逻辑结构、重点介绍多媒体调度系统采用的关键技术及实现主要功能。     

航母滑跃坡道设计探讨

分析航母滑跃坡道特性，提出滑跃坡道典型纵剖面所形成曲线的一种可能的函数表达式并展望该表达式在工程上的应用前景。