基于Internet的空分设备远程监视与故障诊断专家系统的研究

简介了远程监视与故障诊断专家系统在国内空分设备中应用的实际意义，着重分析了大型空分设备远程监视与故障诊断专家系统中远程监视模块和故障诊断模块的开发。     

Photochromism in composite and hybrid materials based on transition-metal oxides and polyoxometalates

Photochromic materials are attractive and promising for applications in many fields. One subject in this area is to prepare and study the photochromism in composite or hybrid materials based on transition-metal oxides or polyoxometalates. Their properties not depend only on the chemical nature of each component, but also on the interface and synergy between them. Since the charge transfer plays a key role in the photochromism of these materials, it is very important to increase the charge (electrons, holes, and protons) interactions between the two components in either composites or hybrids. To realize this, one big challenge is to optimize the two components on a molecular or nanometer scale, which is closely relevant to the constituents, sample history (pre-treatment, preparation, and post-treatment), environment (humidity, presence of reducible or oxidizible matters, light-irradiation wavelength, intensity, time, etc.). Based on these, many novel composite or hybrid materials with improved photochromism, visible-light coloration, reversible photochromism, multicolor photochromism or, possibly, fast photoresponse, have been prepared during the last two decades or three. This may underscore the opportunity of using these composite and hybrid materials as the photonic applications. In present paper, we summarize thoroughly all the recent progress in these subjects.     

An interpolation model to accelerate the frequency-domain response calculation of grounding systems using the method of moments

The transient characteristics of grounding systems are essential for their designs and related electromagnetic-compatibility problems in power systems. Although the method of moments (MoM) is a popular way to analyze the characteristics of grounding systems, it is time-consuming. In this paper, a two-stage method is presented to construct fitted models of the frequency-domain responses of grounding systems to accelerate the calculations of the MoM. In the first stage, the adaptive model-based parameter estimation is used to adaptively choose the most valuable frequency sampling points to construct the initial fitted functions, and then the fitted functions are adjusted in the second stage by comparing the fitted results with those computed by the first principle model at some points. The validation was achieved by a comparison of the numerical results and those obtained by inverse fast Fourier transformation.     

可变时滞系统的控制与仿真

炉温变化时硬质合金真空烧结炉的时滞常数变化很大，常规PID控制不能同时在高温段与低温段满足生产工艺提出的控制品质要求。本文在利用最小二乘法拟合出真空烧结炉时滞常数与炉温变化函数的基础上，PID参数采用经典的CHR整定算法随炉温变化实时整定，并利用MAT—LAB仿真软件对该控制算法在真空烧结炉中的应用进行了仿真研究，结果表明该算法能够实现对真空炉的有效控制，控制系统能够满意地跟踪设定的温度曲线。     

WatchDog失效机理与对策研究

在工业控制领域,程序的失效恢复问题是一重要而棘手的问题,一般采用方法是在程序正常运行必然要经过的地方安插WatchDog复位指令,当遇到程序死锁、跑飞等程序失效问题时,启动WatchDog,使程序恢复正常。但WatchDog并非绝对安全,常常失去有效性,使系统瘫痪。本文对WatchDog失效机理与对策做了一些探讨,并结合工程应用给出了几款有效的硬件WatchDog电路。     

蓝芽技术的安全研究

本文首先提出蓝牙技术,然后分析了蓝牙的安全问题,最后,介绍了蓝牙技术的安全机制。     

新型特洛伊木马技术的研究

本文对特洛伊木马技术所采用的方法进行了分析,介绍了木马程序在植入、加载、隐藏以及在通信方面所采用的方法。在此基础上,分析如何基于动态链接库(DLL)和端口反弹木马技术实现木马程序。最后,给出了防范木马入侵的一般方法。     

Nb在高Ti中Al铁基高温合金的作用

探讨Nb在高Ti中Al铁基高温合金的作用，认为Nb参与了γ-相形成，增加γ-相数量，生成Ni3（Al、Ti、Nb）提高γ-相的固溶温度，从而实现第二相强化。同时，Nb促使碳化物相处于均匀弥散分布状态使合金组织均匀化并显著提高室温、700℃拉伸和持久强度，改善塑性。当Nb含量超过1．38％时γ-相析出达到平衡，μ-相结构发生变化，且数量增加，晶界小颗粒状、块状、链状、μ相析出脆化了晶界，降低合金塑性。     

The Effects of Aging Precipitation on the Recrystallization of CuNiSiCr Alloy

The interaction between precipitation and recrystallization and its effect on the properties of the Cu-Ni-Si-Cr alloy during aging were discussed. The results show that the deformation results in much more dispersed precipitation of the phases. The precipitations have accelerating or retarding effects on the recrys allization. On the formation and growth of recrystallization, the precipitated phases are coarsed or dissolved in front of grain boundaries following a re-precipitation in the recrystallization area.     

氮化硅晶须的研究现状

介绍了晶须的生长机理、氮化硅晶须的制备方法以及影响其生长的因素。阐述了氮化硅晶须增强复合材料的现状,指出加强晶须的基础研究,改进制备技术和降低成本是今后的发展方向。