水泥混凝土路面压浆技术的应用研究

结合鹤壁市S302葛嘴线东段工程实际,研究了公路水泥混凝土路面板底脱空的成因,对板底脱空进行了判断,分析了板底脱空压浆处理的作用,介绍了水泥混凝土路面压浆技术和质量控制方法。     

一种基于小波变化的自适应阈值算法研究

雷达信号处理在整个雷达系统中一直都起着举足轻重的作用,同时也是雷达技术发展中最为活跃的部分。文章主要探讨小波变换在雷达视频压缩中的应用。针对雷达回波信号这些特点,提出了一种基于小波的自适应阈值方法进行雷达回波信号去噪处理,在保留雷达回波的前提下,降低了雷达数字视频的信息量,为雷达数字视频数据的编码打下了良好的基础。而在雷达图像处理中,嵌入式零树小波算法对雷达图像进行压缩取得了不错的效果。利用所提出的信号去噪方法对雷达视频数据进行预处理后在实时性传输方面具有很高的应用价值和前景。     

基于POE的以太网技术在气象智能传感器中的应用

介绍了一种基于POE的以太网技术在气象智能传感器系统中的应用,着重对基于IEEE802.3af以太网供电工业标准的以太网供电系统（POE）的工作原理和实现方法进行了详细的介绍。系统的供电充分利用了POE技术,在传输数据的网线上同时提供电流,这样大大减少了电源系统的复杂度,同时提高了系统电源设计的可靠性。通过实际系统的测试,系统功能和性能方面都达到了预期的设想。     

水泥混凝土路面压浆技术的应用研究

结合鹤壁市S302葛嘴线东段工程实际,研究了公路水泥混凝土路面板底脱空的成因,对板底脱空进行了判断,分析了板底脱空压浆处理的作用,介绍了水泥混凝土路面压浆技术和质量控制方法.     

整体式转向梯形的设计方法研究

为了在整体式转向梯形设计过程中考虑轮胎侧偏的影响,采用了百分比阿克曼校正率对阿克曼转角关系进行了修正.设计过程中使用了MATLAB数学工具箱以及空间运动分析的方法分析转向梯形的空间运动规律,并且考虑四轮定位参数对转角关系的影响.分析结果表明,通过考虑轮胎侧偏影响设计的转向梯形与现有车型的转向梯形参数比较接近,同时通过灵...     

A new hybrid reliability index definition and its application to the structure buckling reliability analysis of supercavitating projectiles

As structure buckling problems easily arise when supercavitating projectiles operate with high underwater velocity, it is necessary to perform structure buckling reliability analysis. Now it is widely known that probabilistic and non-probabilistic uncertain information exists in engineering analysis. Based on reliability comprehensive index of multi-ellipsoid convex set, probabilistic uncertain information is added and transferred into non-probabilistic interval variable. The hybrid reliability is calculated by a combined method of modified limit step length iteration algorithm(MLSLIA) and Monte-Carlo method. The results of engineering examples show that the convergence of MLSLIA is better than that of limit step length iteration algorithm(LSLIA). Structure buckling hybrid reliability increases with the increase of ratio of base diameter to cavitator diameter, and decreases with the increase of initial launch velocity. Also the changes of uncertain degree of projectile velocity and cavitator drag coefficient affect structure buckling hybrid reliability index obviously. Therefore, uncertain degree of projectile velocity and cavitator drag coefficient should be controlled in project for high structure buckling reliability.     

作为地铁接驳手段的公共自行车使用特性分析

本文以苏州公共自行车为研究对象,利用刷卡数据及问卷调查数据分析公共自行车作为地铁接驳手段的使用特性.研究发现,地铁型站点公共自行车的用车时长较短且较为离散,与其他类型站点有显著差异.在接驳地铁的出行者中,公共自行车经常使用者的平均学历较高,也非低收入人群.利用离散选择模型分析地铁接驳方式选择行为可知,接驳方式使用时间是最重要的影响因素,年龄、职业和出行目的等对公共自行车的选择均有显著影响.研究还发现,经常使用公共自行车的出行者在接驳地铁时同样也倾向于选择公共自行车,而不使用者则倾向于选择步行或公交车.     

自然吸气缸内直喷汽油机气流运动的模拟分析

对一台自然吸气直喷汽油机考察了进气道的性能,模拟进气及压缩过程的气流运动,比较进气道与不同燃烧室匹配的效果。结果显示,在高流量系数、中等滚流比进气道的配合下,平顶活塞燃烧室在进气过程中形成的滚流更强,利于在进气初期喷油的均质燃烧;斜坑活塞燃烧室在压缩后期形成的滚流更强,利于在压缩过程喷油的分层燃烧。     

公路隧道双洞互补式通风系统横通道角度研究

依托某公路隧道研究通风横通道角度对双洞互补式通风系统的影响。通过数值模拟,分析不同角度工况下分流3通与汇流3通因阻力损失不同而引起的送风量差别,提出联络风道中汇流3通因阻力损失是确定横通道角度的关键。计算表明,在通风风速较大时,随横通道角度的减小,汇流3通段阻力损失会急剧变大;横通道角度为60°时,有利于通风网络的气流组织。     

New metal fitting geometry and optimization of the swaging parameters for an automobile power steering hose

To solve the power steering (PS) hose oil leakage problem in automobile applications, a new geometry design of the metal fitting is required, and the swaging conditions applied to the PS hose should be optimized. In this study, a new metal fitting geometry for the PS hose was proposed. A CAE simulation for both the proposed and the conventional metal fittings was conducted, and both the stress and the strain in the PS hose were compared. An experimental verification was also performed with these two different metal fittings. Additionally, the swaging conditions were optimized by the durability cycle time, which was measured in an impulse test of the swaged PS hose. For a more economical production, practical working conditions were also recommended and experimentally verified.