基于软交换IP中继媒体网关的实现

随着IP技术的发展，传统的PSTN通信N络也在逐步向IPN络方向发展，下一代N络（NGN）是融合话音、数据和图像的多业务IPN络，是未来通信N络的发展方向。基于当前通信网络的实际情况，简单介绍了基于软交换的中继N关的特点和功能结构。     

40MPa船用高压空气压缩机自动控制系统

40Mh高压空气压缩机是4805厂近期研制成功填补国内空白的高科技产品。为了提高其自动化程度，     

利用网管信息对计费系统进行优化

铁通计费网管系统主要采用HP Openview产品，包括OVO和NNM组件，所有网管监控信息存在后台数据库中。系统前端采用Openview的附属产品OVreportor，可以展示丰富的图表，常用的有折线图、饼图和各种分析表。     

高速公路长大隧道施工动态监测与数值模拟研究

以河北省高速公路目前最长的隧道—黑石岭隧道为例,采用现场监测与数值模拟分析两种手段,对隧道开挖后的位移变形进行了分析研究,得出了一些有意义的结论。     

旅客信息服务系统在地铁中的设计浅析

文章针对地铁旅客信息服务系统实际情况,提出不同系统方案,并进行了优缺点比较。     

UM71补偿电容测试仪

UM71区间自动闭塞设备，目前在京沪、京广、京哈、陇海四大干线都已上道使用。这种无绝缘轨道电路利用谐振原理，把低频调制的FSK信号(4种载频，18种低频)通过钢轨进行传输。由于平行的钢轨具有等效感抗特性，严重影响信号传送的距离，因此在每一闭塞分区，每间隔100m便安装1个33μF的谐振电容，与钢轨的等效电感组成串联谐振电路来提高信号传送距离。     

Nonlinear pitch control of an underwater glider based on adaptive backstepping approach

Underwater gliders are highly efficient and long-ranged autonomous underwater vehicles. The typical dynamic modeling in the vertical plane is of multi-input multi-output(MIMO), which is underactuated while easily affected by the ambient environment. To resolve the problems of MIMO, the dynamic model is transformed into a single-input single-output(SISO) system with two dubious parameters, and an adaptive backstepping controller is designed and applied in this paper. A Lyapunov function has been established with the total energy of the system converged in the controller. Contrast result of simulation has demonstrated that the derived nonlinear controller has higher tracking precision and faster response than the proportional-integral-derivative(PID) control method,which indicates its excellent capability to deal with the controlling problems of underwater gliders.     

基于dSPACE的AMT电控操纵系统试验台设计

以AMT为研究对象,以实现电控操纵选换挡为目标,设计电控操纵系统试验台。由d SPACE控制变速器试验台操纵机构自动完成选换挡动作,通过运动模拟软件计算和试验验证两种方法获得换挡操纵杆运动过程中操纵杆特定点位的空间位置、速度和定向载荷及其变化率等系列参数。对比验证表明该设计方案合理可行,对开发AMT操纵系统测试装置具有借鉴意义。     

摩托车发动机诊断分析系统在整车性能提升中的应用(2)

(上接2015年第1期)图9~图11为发动机前端补气中,发动机NO_x、HC和CO随二次补气管前端管长度的变化情况(发动机转速为6 900 r/min)。试验结果表明,前端管长度对NO_x排放的影响并不显著,而对HC和CO的影响较为明显,与原机相比,增长和缩短前端管长度都不利于高负荷条件下HC的排放控制,而对于中低负荷条件下的CO排放却有明显抑制作用。图12~图14为发动机后端补气中,发动机NO_x、     

南海海底管道冲刷深度预测（英文）

Scour depth prediction of offshore pipelines is of great significance to the design and construction of the submarine pipeline projects. In this paper, based on the CFD software package FLUENT and User Defined Function(UDF), an Eulerian two-phase model, which includes an Euler-Euler coupled model for water and sediment phases, and a turbulent model for the fluid phase, is adopted to predict the scour depth around pipelines. The model is verified by observation data obtained from laboratory experiments. On the basis of the simulations, the factors affecting the scour depth, including the effects of incipient velocity, pipe diameter and sediment particle size and so on, were investigated. Meanwhile, according to formulas of incipient velocity of various sediments, approximate calculation on theoretical scour depths is developed for pipelines of seven stations in the South China Sea, where engineering application information is available.