基于单端电流量的同杆双回线故障定位方法

提出了一种基于同杆双回线单端电流量的故障测距方法。在故障状态下,双回线可以分解成同向网和环流网,其中环流网只与双回线有关,且两端电压为零。根据双回线环流网的特点,只需电流量就可求取环流网中的电压分布。因为双回线环流网中的行波具有两端母线处反射强、故障点反射弱的特点,所以可以根据环流网中行波首次到达测点的时刻为起点,由前行波和反行波电压的最强叠加点所处的时刻和位置进行故障定位。仿真验证表明该方法定位精度高,不受过渡电阻影响。     

高压线路双端测距新算法

提出了一种新颖的超高压输电线路故障双端测距精确算法。该算法采用相-模变换技术和分布参数线路模型,考虑了双端数据的不同步问题,运用拟牛顿法迭代求解非线性方程组。仿真计算其表明具有很高的精度。     

继电保护故障信息系统的通信协议探讨

介绍了继电保护及故障录波器信息处理系统的构成、任务及信息传输的特点、要求和相关的国际标准,提出了故障信息系统的主站和子站的通信协议采用IEC60870 5 103和FTP组合的协议方案,分析了该通信协议如何满足所传送信息的需要及与现有的电力数据通信网络中不同类型通道的结合方式;接着介绍了子站系统内部采用以太网,接入不同类型装置和录波器的方案,提出了协议转换采用尽量下放到接近装置,分散处理的原则;也介绍了与现有的厂、站自动化系统的通信协调;最后分析了故障信息系统兼容或采用IEC61850标准的问题。还介绍了     

三相交流输电线路的电磁环境(一)

本文定量分析计算三相交流输电线路正常运行工频电、磁场对周围环境影响,以及产生电晕时对无线电接收的干扰影响。并分析在输电线路短路状态下其电磁场对周围环境的影响。     

同塔并架多回输电线无线电干扰分析

针对同塔并架多回输电线路的特点 ,讨论了导线相序排列对导线表面场强的影响。并比较四回输电线路三种杆塔的合理选择 ,计算了典型排列方式导体表面场强及同塔并架多回线无线电干扰 ,结果表明各相导线的逆序排列可改善线路两面的干扰状况 ,节省土地资源     

Physical Maltreatment Victim to Antisocial Child: Evidence of an Environmentally Mediated Process.

The well-documented finding that child physical maltreatment predicts later antisocial behavior has at least 2 explanations: (a) Physical maltreatment causes antisocial behavior, and (b) genetic factors transmitted from parents to children influence the likelihood that parents will be abusive and that children will engage in antisocial behavior. The authors tested these hypotheses in the representative Environmental-Risk cohort of 1,116 twin pairs and their families, who were assessed when the twins were 5 and 7 years old. Mothers reported on children's experience of physical maltreatment, and mothers and teachers reported on children's antisocial behavior. The findings support the hypothesis that physical maltreatment plays a causal role in the development of children's antisocial behavior and that preventing maltreatment can prevent its violent sequelae. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

面向旋转构件的高速无线数据采集系统

提出一种基于80C51F021单片机和nRF2401无线数据传输芯片的旋转构件高速无线数据采集系统,系统包括采样端和接收端。采样端固定在旋转构件上,将传感器输出信号进行信号调理和模数转换,并利用无线数字传输技术将数据发送到接收端;接收端将采集数据中继传输到PC计算机进行显示和存储。实验结果表明:该系统采样速率高、数据传输可靠,适用于旋转构件的传感器信号采集。     

基于RS-485总线的调度模拟盘控制系统

针对以往调度模拟盘控制系统采用非智能化功能单元、并行传输方式所带来的种种弊端,例如:易受到干扰、接线复杂、不能实现显示单元自检及动态潮流方向显示等,本文提出一种基于RS-485总线的解决方案。     

信道自适应主动块低频分量丢弃数字图像传输技术

为减少图像传输的数据量,满足信道带宽的要求,在图像发送端以块为单位对图像进行划分,利用离散余弦变换(DCT),按照一定的规则主动丢弃部分块的低频分量,而在图像接收端通过图像重建技术对丢弃的图像数据进行恢复,从而再现原图像。实验结果表明这种数字图像传输技术改善了DCT图像质量。     

Optimization of photo‐aligned ferroelectric liquid‐crystal display under passively addressed driving

Abstract— A ferroelectric liquid‐crystal (FLC) passively addressed 64 × 64 display based on the photo‐alignment technique has been developed. The display matrix has dimensions of 33 × 33 mm², and the FLC layer thickness is about 5 μm. Asymmetric boundary conditions, when only one of ITO surfaces of the display matrix is covered with the photo‐aligning layer while another one is not, have been used for providing both high contrast ratio and steady multiplex operation. The electro‐optical performance of the 5‐μm FLC display is presented, including bistable switching in static operation, optimization in multiplexing operation, and gray‐scale generation.