桥梁0#、1#块施工技术探析

大跨度连续刚构桥0#块施工既是桥梁施工中的关键环节,也是施工难点之一.结合某预应力桥梁施工情况,对桥梁0#块的施工技术进行总结,可供今后类似工程的施工参考借鉴.     

Profile-speed data-based models to estimate operating speeds for urban residential streets with a 30 km/h speed limit

A speed limit of 30 kilometres per hour (km/h) has been widely introduced for urban residential streets to ensure traffic safety and allow these streets to fulfil other intended functions. However, excessive speeds on these roads are very common, causing traffic safety problems and threatening the liveability of neighbourhoods. An effective and active way to deal with speeding is the application of a performance-based design approach, as mentioned in previous research. In a performance-based design approach, street geometrics and roadside elements are selected based on their influence on the desired driving speeds. The relationship between driving speeds and street features therefore needs to be determined. Although several studies have developed operating speed models for urban streets, all of these models were calibrated based on data for streets with speed limits of more than 30 km/h. The present research is designed to investigate the influence of various roadway and roadside characteristics on operating speeds on urban tangent street sections with a 30 km/h speed limit using profile-speed data. A simultaneous equation regression with a three-stage-least-square (3SLS) estimator was used for the modelling effort. The driving speed models developed in this study incorporate several street design factors, which provide helpful information for urban planners and street designers to cope with speeding issues on residential streets.     

混凝土喷射台车工作臂逆向运动学研究

混凝土喷射台车机械臂设计十分复杂,机械臂末端执行器工作路径的控制问题是设计的关键。为解决各关节驱动控制的问题,研究机械臂结构和执行器工作路径的关系,利用D-H法建立机械臂的运动数学模型,给出其逆向运动学解。利用Matlab和COSMOSMotion计算预定喷射路径下机械臂的杆件参数,通过虚拟样机实验仿真机械臂的运动。仿真结果满足工作要求,验证了逆向运动学解的正确性。该方法可应用于类似机械臂的研究。     

基于行波法的中压舰船电网接地故障选线方法仿真分析

为了确保舰船电网的继电保护正确与可靠,本文对舰船电网单相接地故障进行了简单的数值分析,同时运用MATLAB对舰船电网进行数学建模并进行了相关仿真分析,针对舰船电网的特殊环境以及现有接地故障选线技术,验证了基于行波法的舰船电网接地故障选线技术的可行性.     

基于Web2．0的高校图书馆个性化信息服务

摘要本文从Web2．0的涵义与特征、高校图书馆用户个性化信息服务的特点和Web2．0技术在高校图书馆个性化服务中的应用等三个方面论述基于Web2．0的高校图书馆个性化信息服务。     

基于人-车-路耦合振动系统的儿童乘坐舒适性

根据拉格朗日原理,建立了基于人-车-路耦合振动的12自由度动力学数学模型;借助MATLAB/Simulink平台,分析车速、路面不平度、汽车前后轮迟滞性及左右轮相干性的特点;构建了随机路面激励时域模型;采用时域和频域分析了在不同路面及不同车速下汽车对儿童头部、臀部振动影响。研究表明:通过提高路面等级及车速可以提高儿童的乘坐舒适性;儿童对5～10 Hz的低频及15,23 Hz的中频振动最为敏感;适当地降低座椅刚度、提高阻尼及合理地布置座椅位置可以提高儿童的乘坐舒适性。     

基于μC/OS-Ⅱ的热泵热水器控制器设计

热泵热水器是节能环保型产品,智能热泵控制器可自动控制热泵机组安全、稳定地运行.本文介绍了热泵热水器的工作原理并分析热泵热水机组的控制要求,研制成功由ADμc834单片机与三星S3C44B0组成的双核热泵控制器,详细叙述了ADμc834核采集控制装置的设计方法,介绍了基于μC/OS-Ⅱ与μC/GUI的ARM7核图形操作终端的软硬件平台.     

沪宁城际WJ-7B型扣件螺栓轴力衰减规律与复紧周期探讨

高速铁路扣件系统是轨道弹性、轨距、水平调整能力的主要提供者,扣件的可靠性关系到列车运行的安全性和旅客乘车的舒适度等,对于WJ-7B型弹性分开式扣件,其功能的正常发挥很大程度上取决于锚固螺栓的预紧力是否足够。以沪宁城际WJ-7B型扣件系统为例,推导扣件系统螺栓轴力计算方法;结合现场转角测试结果计算锚固螺栓轴力的衰减规律。研究结论为:螺栓轴力稳定在40~60 kN,满足横向力校核结果,在此基础上确定了复紧周期为3~4年。     

基于ARM的嵌入式虚拟示波器系统的设计

基于ARM技术，以S3C44BOX为CPU，在uClinux基础上，通过USB设备来连接装有Labview的PC机，设计了一种嵌入式虚拟示波器系统．uClinux是一种运行于没有MMU的嵌入式微处理器的Linux衍生操作系统，实现了多任务运行．介绍了虚拟示波器的概念及Labview的特点和工作过程．