国铁刚性接触网检测数据分析与评价标准探讨

通过对国内电气化铁路典型刚性悬挂应用情况的梳理,从接触网几何参数、接触线平顺性、弓网受流等方面分析刚性悬挂接触网特征,对比柔性悬挂接触网动态检测参数响应特点,对国铁刚性悬挂接触网各参数动态检测评价值的范围进行了适用性分析,并提出了动态检测评价标准建议值.     

船舶水上交通相对风险随机性的贝叶斯分析

船舶水上交通风险的评估一直是业内研究人员十分重视的研究课题。采用贝叶斯概率理论方法,通过贝叶斯统计、估计,结合国内引航及航运单位的船舶事故的实际情况,进行了事故发生频率与后果情况的贝叶斯概率评估。并着重就贝叶斯方法在船舶水上交通风险评估中的随机性特性问题进行了探讨。结论证明贝叶斯评估方法得到的结果具有良好的评估效果。     

Caching Scheme Based on Power-Law Characteristic in Unstructured P2P Networks

In order to reduce the traffic load and improve the availability of the shared resources in unstructured P2P networks, a caching scheme combining alternative index and adaptive replication (AIAR) is presented. AIAR uses random walk mechanism to disperse the caching information of resources in the network based on its power-law characteristic, and dynamically adjusts replicas according to the visit frequency on resources and the degree information of peers. Subsequent experimental results show that the proposed AIAR scheme is beneficial to improve the search performance of success rate and respond speed. In addition, compared to some existing caching scheme, AIAR can perform much better in success rate, especially in a dynamic environment.     

浅谈现代汽车的自动变速箱

变速箱作为汽车动力传动系统的重要组成部分,对汽车的动力性,驾驶舒适性以及油耗都具有重要的作用,由于自动变速箱运用计算机和电子控制技术实现了汽车的自动变速,能够消除驾车人换挡操作技术的差异,     

基于数据建模的铁路弓网接触力辨识

在对载荷辨识技术应用情况进行分析的基础上,基于铁路弓网综合检测数据,先结合数据特征进行时域分析、频域分析、趋势项消除及区段融合等预处理,后分别采用机器学习中的BP,ELM和LSTM神经网络3种数据建模方法,分别以4个受电弓振动加速度和2个硬点振动加速度为输入,对弓网接触力进行数据建模载荷辨识,并与试验结果进行对比.结果...     

海上风电吸力式三筒导管架基础在砂土中的调平技术试验研究（英文）

For the tripod bucket jacket foundations used in offshore wind turbines, the probable critical tilt angles should be avoided during tilt adjustment operation. Thus, these critical values must be identified by engineers, and remedial techniques must be established prior to the occurrence of the problem. Model tests were carried out for typical tilting conditions of tripod bucket foundations, which were allowed to tilt freely at various penetration depths without interruption by manual operation. ...     

列车以太网物理层一致性测试的应用

列车以太网一致性测试技术是保障列车以太网通信质量的重要手段。文中在研究动车组以太网相关测试规范基础上,总结形成了以太网测试的试验项点,设计了动车组以太网测试试验台,可对以太网物理层信号特征进行测试。在实际测试工作中证明了该设备可对被测设备的多项以太网参数指标实现测量、鉴别、和评判,提升了以太网通信测试能力和列车以太网系统集成的能力。     

建设摩托官方旗舰店获天猫先锋奖

在2012天猫汽车年度高峰论坛上,建设摩托官方旗舰店荣获2012年度天猫汽车电商行业先锋奖。作为中国摩托车行业首家入驻天猫商城的摩托车官方旗舰店,建设成为电商行业中第一家真正实现网上销售的摩托车企业,建设摩托也因此成为摩托车网销的先锋品牌。     

加气喷嘴优化设计数值仿真

为了提高管道输送效率,让空气与泥浆在管道内部均匀混合,需要设计能量损失小、混合效果好的加气喷嘴,为此建立喷嘴几何模型,利用CFX软件模拟内部流场,计算不同螺旋管道直径和螺距条件下的混合效率和能量损失,对比分析喷嘴效果,得到喷嘴的最佳螺旋管道直径和螺距。     

A method to analyze the voltage-actuation response of a pre-strained circular dielectric elastomer actuator model

Dielectric elastomers (DEs) are the polymers capable of inducing deformation under electrical stimulation. When subject to a voltage across its thickness, the material reduces in thickness and expands in area. This paper presents a new method to analyze deformation and stress distribution response of the dielectric elastomer actuator (DEA) model under different applied voltage. An equal-biaxial pre-strained circular actuator model was built. The Yeoh strain energy potential and the collocation method are used for describing the large strain actuation response and stress distribution. The study in this paper has shown that: the stress and the stretch distributions in the passive region of the DE actuator depend on the radial distance from the center at the calculation point of the passive region and the magnitude of the applied voltage; with the same excitation applied voltage, we can get a larger deformation actuation by choosing an appropriate pre-stretch ratio; the influence of the non-ideal material has seriously affected the actual deformation of the DE actuators. This analytical model has a reference potential for the design optimization of high performance DEA systems and the model-based control of the DEA robot.