基于建康管理技术的机载计算机智能故障诊断方法

为了满足飞机机载电子设备以状态监控为基础的视情维修保障策略,提升设备可维护性,提出了一种基于在线检测、故障预测、辅助决策的健康监控管理故障诊断方法,支持对机载电子设备的健康状态进行预测和评估。通过划分机载电子设备子功能的敏感威胁区域,对这些区域设计专门的威胁预警监控电路,进行功能危害监控,建立推理监控模型对监控电路故障进行预警监控,结合辅助决策的方式对预警到的故障进行定位,实现对电子设备的智能故障诊断。通过FMEA的分析与故障注入测试验证,该预警电路、推理模型和辅助决策能有效的预测故障及定位,具有较高的故障预测覆盖率,可提高机载计算机的维修性、降低维修时间,在电子设备视情维修策略上具备工程应用价值。     

基于核电管道评估系统的硬件与故障诊断设计

以核电管道评估系统为对象,对其核心部分硬件系统的故障诊断与控制设计进行了研究。利用程控放大、幻象供电、故障诊断等电路设计了硬件调理模块。通过Keil软件对STM32芯片嵌入式软件编程的方式实现了硬件系统的控制与故障诊断功能,并由设计的串口通信协议经RS232与软件系统通讯。通过Labview软件开发了硬件自动化测试平台和故障诊断监测程序,保证硬件系统可靠性的同时提升了测试效率并减少了人力成本。设计的硬件控制与故障诊断模块满足要求,已成功应用在出口国外某核电厂的管道评估系统中,为核电厂安全经济可靠地运行提供了保障。     

Raney Ni catalysts derived from different alloy precursors Part II. CO and CO2 methanation activity

Catalytic activity, in conjunction with reaction mechanism, was studied in the methanation of CO and CO₂ on three Raney Ni catalysts derived from different Ni-Al alloys using different leaching conditions. Main products were CH₄ and CO₂ in CO methanation, and CH₄ and CO in CO₂ methanation. Any other hydrocarbon products were not observed. Over all catalysts, CO methanation showed lower selectivity to methane and higher activation energy than CO₂ methanation. The catalyst derived from alloy having higher Ni content using more severe leaching conditions, namely higher reaction temperature and longer extraction time, showed higher specific activity and higher selectivity to methane both in CO and CO₂ methanation. In CO and CO₂ methanation on Raney Ni catalyst, catalytic activity was seen to have close relation with the activity to dissociate CO This paper was presented at the 2004 Korea/Japan/Taiwan Chemical Engineering Conference held at Busan, Korea between November 3 and 4,2004.     

循环中值滤波在消除可控震源地震资料噪声中的应用

中值滤波是地震资料去噪处理中的常用工具,由于其对去噪资料有较严格的要求,使去噪效果不甚理想。可控震源地震资料正好满足中值滤波的应用前提,但又存在道数少,边界效应所占比例大的缺陷。根据可控震源资料的特点,提出了将去噪记录横向首尾相连,然后进行中值滤波,以克服边界效应的循环中值滤波方法。理论模型测试和实际可控震源资料处理证明了这种方法的可行性。     

高压开关柜状态检修的研究

本文论述了高压开关柜的局部放电检测技术,提出以局部放电检测为基础的高压开关柜状态检修的技术方法,探索建立高压开关柜状态检修体系,全面保障高压开关柜的安全运行。     

Central crack in a piezoelectric disc

This study is concerned with the general solution of the field intensity factors and energy release rate for a Griffith crack in a piezoelectric ceramic of finite radius under combined anti-plane mechanical and in-plane electrical loading. Both electrically continuous and impermeable crack surface conditions are considered. Employing Mellin transforms and Fourier series, the problem is reduced to dual integral forms. The solution to the resulting expressions is expressed in terms of Fredholm integral equation of the second kind. The solutions are provided to study the influence of the crack length, the crack surface boundary conditions on the intensity factors and the energy release rate.     

基于故障诊断的生产过程安全管理系统

介绍了利用计算机对生产设备进行数据采集和信号分析，对设备运行状态进行监测，发出故障报警，进行故障诊断和预测，讨论了灰色故障诊断方法以及基于GM（1，1）模型的故障预测方法，并在此基础上开发了一套状态监测及生产过程安全管理系统。     

Wigner谱在往复式机械监测中的应用

本文讨论了一种时间一频率两维分布－Ｗｉｇｎｅｒ谱．指出Ｗｉｇｎｅｒ谱具有很好的跟踪时变信号的特性，适用于非平稳信号的分析，应用于往复式机械的状态监测，得到了较好效果．     

On the modal curve of nonlinear normal modes

In a nonlinear holonomic conservative system having two-degree-of-freedom, the modal curves of normal mode vibrations are investigated investimgated by the harmonic balance method. The general procedure to compute the modal curve is suggested. Even if the linearized frequencies of the system are satisfied with the commensurability condition under which the approaches using the perturbation method have the problem of small divisor, the modal curve can be obtained by this method, provided that the fundamental harmonics are dominant when the normal modes are expanded in Fourier series in time domain. As an example, in a system with cubic nonlinearity the modal curves are computed analytically and numerically to compare both results.     

基于微处理器的智能化旋转机械状态监测与故障诊断系统

介绍了以准１６位徽处理器为核心的智能化旋转机械状态监测与故障诊断系统的工作原理及硬件与软件设计。系统由信号测量、数据采集、数据分析组成，能实现对旋转机械的在线监测、报警、转子振动分析和故障的模糊诊断。