Development of a numerical comparator for protective relaying: PartII

This paper describes the testing of a new power system numerical relaying concept. The new technique is applied to distance relaying to offer improved reliability and security of the relay, and improve the speed of relay operation. To validate the algorithm's performance, the scheme was analyzed under a variety of test conditions and compared with conventional relay concepts. This paper presents the results of the testing and shows that the new relaying scheme operated with a high level of security and dependability for all of the test cases. The tests show improvements that the new scheme can offer in comparison to the conventional schemes     

基于扩展无网格法的机电虚拟裂纹闭合法

为提高含裂纹压电材料断裂参数的求解效率和精度,基于扩展无网格理论,引入无网格辅助网格结合哑节点断裂压电单元,提出了基于扩展无网格法的机电虚拟裂纹闭合法。可很好地模拟裂纹尖端奇异性,简化求解过程,提高计算精度。并讨论了不同高斯点个数、不同裂纹长度对能量释放率计算结果的影响,与解析解和基于有限元法的机电虚拟裂纹闭合法计算结果进行了比较,数值算例结果表明本方法正确可行且具有较高的精度。     

Performance of multiple access CSK communication system with DF cooperative strategy

A multiple access chaos shift keying cooperative communication (MA-CSK-CC) system over Rayleigh fading channels and in the presence of Gaussian white noise is investigated in depth in this paper. The simplified half-duplex with a single relay decode-and-forward (DF) cooperative strategy is proposed to illustrate and analysis as an example. Exact and approximation bit-error-ratio (BER) performance expressions are derived. Simulation results demonstrate that the proposed system has a prominent advantage of high BER performance over the conventional multiple access CSK systems that have a single path to transmit signal at the same data rate over Rayleigh fading channels with additive Gaussian white noise. Moreover, based on the BER performance analysis, some useful results are also derived such as the relationships between BER versus spread spectrum factors, BER versus the number of users, etc.     

Improvement in interfacial shear strength and fracture toughness for carbon fiber reinforced epoxy composite by fiber sizing

Carbon fiber was sized by a thermoplastic polymer solution mixed with a compatible amine monomer. The effect of sizing agent on tensile strength was studied by single fiber strength testing. Interfacial properties of re‐sized carbon fiber/epoxy composite were investigated, with special emphasis on the improvement in both interfacial shear strength and interfacial fracture toughness. The interfacial fracture toughness of composites was characterized by calculating the effective interphase fracture energy rate through the information obtained from the force–displacement curve in the micro‐bond test. Fracture topography of micro‐bond specimen was observed to discuss the interfacial fracture mechanism. POLYM. COMPOS., 35:482–488, 2014. © 2013 Society of Plastics Engineers     

乡村型多功能变频供水系统的设计与实现

本文介绍了利用人机界面（HMI）变频器（VVVF）和PLC构成的多功能小型恒压供水系统的设计与实现，系统具有自动化程度高，便于维护，耗电量小等优点。广泛适用于乡镇，农村等基础设施薄弱地区。     

Modelling the Garden of Perfect Brightness

The Yuan Ming Yuan, the Garden of Perfect Brightness, was the culmination of the art of Chinese Imperial gardens. Covering 350 hectares (875 acres) northwest of Beijing, it included 140 distinct sites, 2000 structures, thousands of pieces of furniture and precious objects, countless plants. It was almost totally destroyed in 1860 at the end of the second Opium War by English and French troops in one of the worst acts of cultural vandalism in recorded history. Rebuilding it has proven impossible, but now computer technology, based on 130 years of scholarly documentation makes it possible to build an accurate and detailed model, and will allow us to experience at least virtually the beauty and grandeur that was the Yuan Ming Yuan. This paper describes a project to build such a model, and details the main challenges and difficulties encountered. While commercially available graphics workstations and modelling software can take us most of the way in this task, they fall short with the modelling of natural phenomena such as plants, rocks and bodies of water. In addition the sheer size of the resulting database pushes rendering engines past their limits.     

鞍钢冷连轧机组65Mn工具钢生产实践

为了扩大冷轧品种结构,鞍钢股份有限公司冷轧厂对冷连轧机组65Mn工具钢生产工艺进行了研究,采用冷连轧机轧制与罩式炉退火相结合的生产模式,增加了预退火工艺,制订焊接与轧制工艺优化方案,实现了冷连轧机组65Mn工具钢的稳定生产。     

V形槽静电超声传感器静电场不均匀性研究

分析V形槽静电超声传感器微气隙结构研究静电场不均匀性,用解拉普拉斯方程的方法解的单个V形槽面电荷密度.通过建立π/4角两平板电容器模型,提出V形槽静电传感器电容值的定量计算方法,得到与试验相接近的结果.     

日本预制住宅结构接合部设计概述

对于预制建筑结构来说,可靠的接合部设计方法与连接方式是保证预制结构整体性能与质量的关键。不同的结构形式,对应不同的预制工法,接合部的设计方法通常也不相同。本文介绍了日本预制结构的接合部的类型与现行的设计依据,总结了接合部的设计性能目标与设计方法,供我国住宅建筑设计从业人员参考。