基于工控机的机车劈相机启动继电器试验台研制

设计了一种基于工控机的机车劈相机启动继电器试验台,可以对各种机车的劈相机启动继电器性能参数进行测试,自动判断合格与否,并可以对测试结果进行存档、打印。     

便携式矿井提升机性能测试仪设计

提升机是矿井生产的"咽喉",其运行的安全可靠状况,直接影响矿山生产人员的生命安全和矿井生产能力.文章介绍了一种便携式矿井提升机性能测试仪设计,该系统在采集提升机的基本参数后,实现对采集的各路数据进行存储和LCD显示及打印,对提升机的某些故障进行声光报警.     

基于虚拟仪器的性能测试参数电子数据表的设计与实现

测试参数生成电子数据表是测量系统中的一个重要环节,本文介绍了基于LabVIEW软件,实现测试参数自动生成电子数据表的设计,给出了详细的设计方法和步骤,实践证明该方法是行之有效的.     

基于VB和MATLAB的压缩机性能测试软件系统

依据压缩机气动性能试验的国家标准,在对压缩机各项参数的测试计算方法研究的基础上,开发了压缩机性能测试系统,采用 VB 和MATLAB 混合编程的方法实现了对压缩机性能参数测试进行高效计算,重点介绍了该系统的原理和工作流程,经过现场的运行和测试,该系统计算准确、高速、高精度,适用于压缩机参数测试计算.并且使用和维护都非常方便.     

软件性能测试在地质资料管理系统中的应用

介绍了在中国石化地质资料管理信息系统建设项目中,通过使用性能测试及系统监控软件,实现了对该系统的性能测试任务。并简要介绍了Web系统性能测试的通用过程和测试手段,进而确保系统的稳定可靠运行。     

通风机性能计算机辅助测试系统

介绍了测试风机生能的计算机辅助测试系统，本系统实现了风机性能参数的自动测试和计算，并可以对风机运行过程进行实时报警和远程通信。建立了风机性能测试数据库系统，以有效管理所有的试验数据。     

液压元件电驱动的可靠性分析

从对液压阀驱动和电机驱动两方面阐述了实现驱动可靠性可采取的方法,介绍了实现驱动自保持和闭锁的措施,并提出了防止误操作的解决方案.通过一系列的措施可提高系统的抗干扰能力、增强系统的可靠性.     

田湾核电站TXP系统调试与优化

田湾核电站是国内首个实现全数字化仪控系统的核电站,正常运行仪控系统采用西门子公司的TXP控制系统,负责电站电力生产过程的控制和监视.介绍田湾核电站TXP系统的结构及功能,及TXP系统主要调试项目,并对TXP系统调试期间遇到的主要问题及处理措施进行了分析与总结.     

一种实时以太网模型及其性能测试实现

本文介绍了工业以太网和实时以太网的相关概念,给出了一种实现模型,并提出了利用WinPcap库测试IEC61784-2中有关性能指标的方法.     

PCB功能测试系统的设计与实现

本文介绍了一种搭建PCB功能测试系统的方法。该测试系统采用总线结构的思想,利用继电器矩阵灵活配置输入/输出端口的特点,将测试资源和被测单元(UUT)的信号连接到总线上,实现信号间互通。系统自动化程度高,可靠性和扩展性强,使用方便灵活。     

Minimal Realization of Linear Graph Models for Multi-physics Systems

An engineering system may consist of several different types of components,belonging to such physical"domains"as mechanical,electrical,fluid,and thermal.It is t...     

Non-monotonic material contrast in scanning ion and scanning electron images

30 keV Ga⁺ focused ion beam induced secondary electron (iSE) imaging was used to determine the relative contrast between several materials. The iSE signal compared from C, Si, Al, Ti, Cr, Ni, Cu, Mo, Ag, and W metal layers does not decrease with an increase in target atomic number Z₂, and shows a non-monotonic relationship between contrast and Z₂. The non-monotonic relationship is attributed to periodic fluctuations of the stopping power and sputter yield inherent to the ion–solid interactions. In addition, material contrast from electron-induced secondary electron (eSE) and backscattered electron (BSE) images using scanning electron microscopy (SEM) also shows non-monotonic contrast as a function of Z₂, following the periodic behavior of the stopping power for electron–solid interactions. A comparison of the iSE and eSE results shows similar relative contrast between the metal layers, and not complementary contrast as conventionally understood. These similarities in the contrast behavior can be attributed to similarities in the periodic and non-monotonic function defined by incident particle–solid interaction theory.     

Application of Feature Extraction through Convolution Neural Networks and SVM Classifier for Robust Grading of Apples

This paper proposes a novel grading method of apples,in an automated grading device that uses convolutional neural networks to extract the size,color,texture,an...     

分布动态载荷识别的抗噪处理

针对正交多项式频域法在用多种响应对矩形薄板进行载荷识别中抗噪性较差的问题,综合运用平均法、矩阵预处理和奇异值截断法等方法对之进行改善,并引入空间映射的思想,将该方法的应用范围拓展为复杂的模型.利用仿真算例,证实了该方法具有较好的抗噪性.     

基于MELTAC-N平台的核电厂安全级DCS环网研究与测试

针对工程实践中环网通讯相关问题的处理缺乏理论基础及国产化安全级DCS平台的开发缺乏成熟经验借鉴问题,对基于MELTAC-N平台核电厂安全级DCS环网的软硬件实现进行了研究。提出了安全级DCS环网双环网冗余设计、光切换开关设计等硬件设计方法,以及以RPR协议为基础,采用全数据收发策略的软件设计方法。在CPR1000安全级DCS平台上对安全级DCS环网的可靠性及实时性进行了评价,并进行了容错能力、响应时间及响应时间稳定性测试验证实验。结果表明,基于MELTAC-N平台安全级DCS环网软硬件设计具有较好的容错能力及响应时间稳定性。     

Fractional order nonsingular terminal sliding mode control for flexible spacecraft attitude tracking

This paper investigates a fractional terminal sliding mode control for flexible spacecraft attitude tracking in the presence of inertia uncertainties and extern...     

Limits of topographic measurement by the scanning tunnelling and atomic force microscopes

Parameters describing the topographic character of a surface (height, surface wavelength, slope and curvature) can be derived from equivalent sinusoidal profiles. The response of a surface-measuring instrument may be modelled in terms of instrument parameters such as stylus radius, and scanning range and resolution. The performance of the instrument may then be mapped as a zone in amplitude-wavelength (AW) space to show the sinusoidal profiles it is capable of measuring. In a first-order analysis the STM and AFM are considered as equivalent to contact-stylus instruments with a notional stylus radius equal to the tip radius plus the gap. Comparisons between different instruments and types of instrument are readily made by mapping in AW space. The error arising from convolution of the sinusoidal profile with that of the finite tip may be quantified and plotted as contours in AW space.     

气化炉三维扫描测量与数据处理

以德士古气化炉耐火砖的内壁蚀损检测设备为基础,对采集到的点云数据做了进一步处理.通过对数据的筛选和剔除,实现了数据点的平滑降噪细化和精简.然后利用点云对整、网格划分和分色显示等方法,最终完成了内壁腐蚀情况的三维建模.重点讨论了点云数据的预处理及后处理的方法,并根据内壁耐火砖的腐蚀阈值,提出了一种气化炉内壁腐蚀区域的识别与分割方法.对耐火砖的腐蚀分析、气化炉的生产与维修提供了可靠依据,并在工程应用中获得了一致认可.     

奥氏体不锈钢表面双辉等离子渗锆的动力学

利用双辉等离子渗金属技术在0Cr18Ni9Ti奥氏体不锈钢表面制备了一层均匀、致密、呈良好冶金结合的渗锆合金层,并对1 060℃下的渗锆动力学进行了研究。结果表明:随着距锆合金层表面距离的增加,锆元素的含量呈梯度递减,扩散系数逐渐减小,而扩散激活能逐步增大;在1 060℃采用双辉等离子技术渗锆时,渗锆合金层表层的空位密度为2.945×(1012~1013)cm-2,与相同温度下采用常规渗金属工艺相比,提高了1~2个数量级。     

EXPERIMENTAL RESEARCH AND DESIGN ON HEAT TRANSFER OF EVAPORATOR USED IN THE LARGE QUICK FREEZE PLANT

The evaporator is the main part of a quick-freeze equipment. There are many factors influencing the heat transfer coefficient of an evaporator. The most important factors among them are the fin shape, tube diameter, distance of fin space, frost, and velocity of air flow etc. They mainly influence the thermal efficiency of an evaporator, and therefore its thermal efficiency has direct relationship with the whole efficiency of the quick freeze plant. Evaporators with different structural types have different heat transfer efficiency. In order to obtain high efficiency structure of evaporator, 8 evaporator models with different fin shape, tube diameter and tube arrangement are analyzed and compared. The calculation results show that the integral waved fins, equilateral-triangle arranged small diameter tubes and varying fin-spacing has the highest heat transfer coefficient. The experimental result also shows that the evaporator with this type of structure has better thermal efficiency. The experimental result is in good agreement with the calculation result. It can instruct engineering design for usual designer. A real quick-freeze equipment is designed and put into production. The result shows that, compared with traditional domestic quick-freeze equipments, this equipment decreases by 40% in size and by 20% in energy consumption.