一种新型接触网开关综合监控系统的设计与实现

针对电气化铁路接触网开关集中控制的要求,提出了一种新型光纤通信分布式微机监控系统方案,给出了系统结构,硬件及软件架构设计.实验及现场运行表明,该系统设计先进,通信可靠,运行稳定     

Novel material of hydrogen generation

A novel aluminum alloy which could react with water and generate hydrogen at room temperature was prepared via mechanical alloying (MA). The results shows that milling time, additives and mass ratio have a significant role in the hydrogen production rate. The highest hydrogen production rate of alloys reaches 95% of theoretical value. The velocity of hydrogen generation reaches more over 200 mL/min for a gram alloy. Active materials (Ga and In) included in the aluminum alloys can be recycled and used repeatedly. The hydrolysis reaction between aluminum and H₂O will take place and release a large amount of heat, which contributes to increasing the velocity of hydrogen generation. The reaction products consist of AlO(OH) and hydrogen.     

船撞桥梁下部结构撞击力研究

近年来,船舶撞击桥梁的事故时有发生,严重威胁了桥梁结构安全和城市交通的运营。为减小船撞桥带来的损失,需提高桥梁的抗撞能力。为达到既能保护桥梁又能在经济上实现最优化的效果,必须了解桥梁河段内船舶对桥梁的最大撞击力,借助于ANSYS/LS-DYNA非线性有限元程序,仿真模拟各种情况下船撞桥的过程,分析归纳撞击力结果,总结出简化的撞击力计算公式,并与各规范公式进行比较,为该研究方向或工程设计提供一定的参考。     

矮塔斜拉桥结构动力性能分析

以2×85m跨度桥梁为例,运用Midas/civil有限元软件建立相同跨度的矮塔斜拉桥、连续刚构桥及传统斜拉桥空间梁单元模型,研究这3种桥梁形式动力性能的相似性及差异性,通过对比,凸显矮塔斜拉桥的动力性能特点。     

基于Hessian特征的视网膜血管图像的增强滤波算法

提出了一种基于Hessian特征的视网膜血管图像的增强滤波算法,分析了Hessian特征值对各类形状的抑制和加强作用,将Hessian矩阵的特征值与特征向量应用于视网膜血管特征的响应函数及形态学和非线性扩散处理的各个环节,并选择合理的尺度空间范围和尺度空间增量,调节因子而平滑非线状区域和锐化增强血管区域,本文算法在同等准确率下具有较高的稳定鲁棒性。     

三维曲面船体外板数学展开方法研究

为了实现船体外板展开的自动化以及对展开精度的控制,在手工撑线法展开船体外板的理论基础上,提出一种三维船体曲面外板展开的新方法——小曲面三角形法。介绍三角形法展开船体外板的机理,理论分析三角形法展开船体外板的可靠性与精度,利用TRIBON软件产生的外板数据,对其进行三角形法展开,将得到的结果与TRIBON生成的船体外板展开图进行对比,验证三角形法的可靠性与精度。     

毂帽鳍对调距桨推进效率影响的数值研究(英文)

Numerical simulation is investigated to disclose how propeller boss cap fins (PBCF) operate utilizing Reynolds-averaged Navier-Stokes (RANS) method. In addition, exploration of the influencing mechanism of PBCF on the open water efficiency of one controllable-pitch propeller is analyzed through the open water characteristic curves, blade surface pressure distribution and hub streamline distribution. On this basis, the influence of parameters including airfoil profile, diameter, axial position of installation and circumferential installation angle on the open water efficiency of the controllable-pitch propeller is investigated. Numerical results show: for the controllable-pitch propeller, the thrust generated is at the optimum when the radius of boss cap fins is 1.5 times of propeller hub with an optimal installation position in the axial direction, and its optimal circumferential installation position is the midpoint of the extension line of the front and back ends of two adjacent propeller roots in the front of fin root. Under these optimal parameters, the gain of open water efficiency of the controllable-pitch propeller with different advance velocity coefficients is greater than 0.01, which accounts for approximately an increase of 1%-5% of open water efficiency.     

基于 DEFORM 的正挤结合侧挤大变形工艺研究

等径角挤压被认为是最具工业化应用前景的大塑性变形技术之一,但其局限限制了其工业化应用。文中在常规等径角挤压技术的基础上提出了一种正挤压结合侧向挤压新工艺,采用DEFORM-2D软件对该新工艺进行了数值模拟。结果表明：这种新型工艺具有单道次变形量大且均匀的特点,为高效制备大尺度块体超细晶材料提供了新途径,但挤压时所需载荷也较大。因此,需通过进一步的工艺参数优化,为模具设计和选材提供一定的保障。     

浅谈大型船舶舱口围地面组装及整体吊装方案

本文介绍舱口围地面组装及整体吊装方案实施过程中,如何进行精度控制,减少整体吊装变形,实现舱口围组装与舱口盖安装调试工作转移到地面完成。     

基于熵权-云模型的环渤海邮轮港口竞争力评价

以环渤海邮轮港口为研究背景,从经济条件、交通条件、旅游条件、港口条件、服务水平和发展潜力等6个方面构建了港口竞争力评价指标体系;利用熵权-云模型将定性的描述转化为定量的测度,对环渤海邮轮港口竞争力进行了评价;运用云相似度算法分析了大连邮轮港口、天津邮轮港口和青岛邮轮港口的竞争力.结果表明:大连、天津及青岛3个邮轮港口的竞争力评价等级均为"强",但是,大连邮轮港口在"服务水平"和"发展潜力"上、天津邮轮港口在"经济条件"和"服务水平"上、青岛邮轮港口在"交通条件"和"发展潜力"上处于竞争劣势.