小波变换结合纠错编码的半透明数字水印

该文结合实际应用需要提出了半透明数字水印的概念．并研究了带参数的双正交整数小波的构造．结合带参数的整数小波变换与纠错编码设计了一种半透明数字水印．带参数整数小波的使用，提高了水印的安全性．根据小波域量化噪声自适应地确定嵌入强度，并结合纠错编码．提高了抗攻击能力．实验表明该算法有较强的抗JPEG压缩和图像处理的能力．     

基于最优一维分解的图像超分辨方法

提出了一种用分离变量的一维函数乘积形式逼近二维图像数据的方法，通过在一维空间的超分辨处理，很容易实现对图像的超分辨处理。从理论上证明了这种表达是最优的。实际结果显示了超分辨的效果好，计算量小。这种方法也可应用于图像处理的其他领域和海量数据信息特征提取。     

低压空气电弧动态特性仿真及分析

在计算流体动力学（CFD）商用软件包二次开发的基础上针对低压断路器简化灭弧室,采用磁流体动力学（MHD）理论建立了三维电弧仿真模型.仿真计算结果描述了电弧弧柱收缩、等离了体喷流和电弧形态等相关现象,研究发现磁场、出气口面积的增大可加速电弧运动,但出气口面积到达一定程度后,其大小变化对电弧运动的影响很小,而栅片的存在则对灭弧室气流具有一定阻挡作用.电弧运动的实验结果验证了仿真模型的合理性.     

混合样本线性模型参数M估计的强相合性

研究了P混合, 混合和ψ混合样本线性模型中的M估计,在较弱的矩条件和混合系数条件下,获得了M估计是强相合的充分条件.与相应结论比较,有了较大的实质性改进.     

一种新的中压真空断路器三相同期在线监测方法

针对单独利用短时能量分析法在线监测断路器机械状态时可靠性较低的缺点,该文研究了利用脱扣线圈电流包含的信息来排除机械干扰信号带来的影响,从而提高断路器三相同期性在线监测的可靠性。通过对实际振动信号的分析得出,该方法可以屏蔽掉大范围的干扰噪声,显著提高短时能量法从现场含复杂噪声的振动信号中提取出振动起始时刻的可靠性。并与单独使用短时能量分析法和小波包提取法进行了比较。试验中将该方法应用于ZN12-35型真空断路器分合闸时的振动信号分析,准确得到了空载状态下三相分合闸的同期性。试验结果表明,此改进方法明显提高了短时能量法从振动信号中提取三相同期性的可靠性。     

永磁机构的微机控制系统

利用ＣＰＵ技术,对配有永磁操动机构的真空断路器控制回路进行了研制,通过信号采集和处理,实现了电器的智能控制,并与上位ＰＣ机通讯传递数据,生成报表。     

Influence of Copper Vapor on Low-Voltage Circuit Breaker Arcs During Stationary and Moving States

The influence of copper vapor on the low-voltage circuit breaker arcs is studied. A three-dimensional （3-D） magnetohydrodynamics（MHD） model of arc motion under the effect of external magnetic field is built up. By adopting the commercial computational fluid dynamics （CFD） package FLUENT based on control-volume method, the above MHD model is solved. For the mediums of air-1% Cu and air-10% Cu, the distributions of stationary temperature, pressure, electrical potential and the arc motion processes are compared with those of a pure air arc. The copper vapor diffusion process in the arc chamber and the distribution of copper vapor mass concentration are also simulated. The results shows that the copper vapor has a cooling effect on the arc plasma and can decrease the stationary voltage as well. Moreover, the presence of copper vapor can decelerate the arc motion in the quenching chambers. The maximal copper vapor concentration locates behind the arc root because of the existence of a ＂double vortex＂ near the electrodes.     

Simulation and Experimental Study of Arc Column Expansion After Ignition in Low-Voltage Circuit Breakers

The dynamic process of arc pressure and corresponding arc column expansion, which is the main feature after arc ignition and has a significant effect on the breaking behaviour of low -voltage circuit breakers, is studied. By constructing a three dimensional mathematical model of air arc plasma and adopting the Control Volume Method, the parameters of arc plasma including temperature and pressure are obtained. The variations of pressure field and temperature field with time are simulated. The result indicates that there are six stages for the process of arc column expansion according to the variation of pressure in arc chamber. In the first stage, the maximal pressure locates in the region close to cathode, and in the second stage the maximal pressure shifts to the region close to the anode. In the third stage, the pressure difference between the middle of arc column and the ambient gas is very large, so the arc column begins to expand apparently. In the fourth stage, the pressure wave propagates towards both ends and the maximal pressure appears at the two ends when the pressure wave reaches both sidewalls. In the fifth stage, the pressure wave is reflected and collides in the middle of the arc chamber. In the last stage, the propagation and reflection of pressure wave will repeat several times until a steady burning state is reached. In addition, the experimental results of arc column expansion, corresponding to the arc pressure variation, are presented to verify the simulation results.     

Piers硼烷的应用研究进展

基于主族元素的化学试剂和催化剂是当前研究的热点之一。HB(C₆F₅)₂具有强路易斯酸性的硼中心，因此在小分子活化中具有特殊地位，可以活化包括一氧化碳在内的多种惰性小分子和化学键。同时，由于HB(C₆F₅)₂具有可衍生化的硼氢键，因此也被用于构建含硼催化剂以及受阻路易斯酸碱对。经过多年的发展和使用，HB(C₆F₅)₂被广泛应用于合成化学，并且以其发现者命名为Piers′Borane即Piers硼烷。综述了Piers硼烷近年来的应用进展，旨在为硼化合物在有机催化和小分子活化等领域的研究提供参考。