色散管理孤子

分析了色散管理孤子（DMS）的基本原理和特性，并通过数值计算对DMS的传输进行了模拟，证实了DMS具有诸多比普通孤子更为优越的性能。同时也对密集色散管理孤子（DDMS）做了介绍，并在数值计算的基础上将其与类线性和普通DMS传输作了比较，发现DDMS在高速窄脉冲情况下有更好的传输特性。     

基于DMS架构的配电网施工现场安全监控系统的研究

为了实现对配电网施工现场安全监控,提出基于DMS架构的配电网施工现场安全监控系统.构建配电网施工现场安全管控的统计信息分析模型,采用DMS架构体系进行配电网施工现场安全监控的嵌入式体系构架,运用分布式信息融合方法进行配电网施工现场安全监控的过程控制,提高建配电网施工现场安全监控和管理能力.仿真结果表明,采用该方法进行配电网施工现场安全监控的过程控制能力较好,提高了对配电网施工现场安全管理和过程控制能力.     

Real-Time Disk Scheduling for Multimedia Applications with Deadline-Modification-Scan Scheme

Real-timedisk scheduling (RTDS) is important for time-critical multimediaapplications. In conventional approaches of real-time disk scheduling,such as SCAN-EDF, the seek-optimizing SCAN scheme is appliedto reduce the disk service time of the real-time EDF schedule.Since only tasks with the same deadline are seek-optimized, theobtained improvement of SCAN-EDF is limited. In this paper, basedon the maximum-scannable-group (MSG) concept, a deadline-modification-scan (DMS or DM-SCAN) algorithm is proposed.Our algorithm uses MSG to automatically decide the suitable taskgroups for seek-optimizing. Based on the MSG concept, we repeatedlyapply DMS to further increase disk throughput to support moretasks. We have implemented the proposed algorithm on UnixWare2.01. The appropriate problem behaviors and parameter valuesto yield good solutions are investigated. Experiments show thatDMS is better than conventional approaches in both the obtaineddisk throughput and the supported tasks. Moreover, our proposedapproach can schedule task sets that are not schedulable by EDFand SCAN-EDF.     

碳酸二甲酯合成工艺进展

讨论了碳酸二甲酯的合成工艺,主要介绍氧化羰基合成工艺,并对碳酸二甲酯取代硫酸二甲酯和光气市场的可能性进行了分析。     

面向对象编程技术在配电网应用软件开发中的应用

文章阐述了一种基于面向对象的程序设计技术开发配电网应用软件的方法,给出了配电系统中元件类的定义,并结合实际经验给出了一个潮流应用的示例,应用经验表明,将面向对象技术应用于配电系统应用软件的开发工作可以缩短开发周期,减小软件移植的工作量     

The Design, Development and Implementation of the Integrated EMS/DMS for the Project of Beijing Power System

l.IntroductionTheBeijngpowersystemisthelargestdistrictpowersysteminChina.Themaximumloadwasmorethan47ooMWinl997andisplannedtoabout6oooMWin2OOO.Itcoversl6,9Oosquarekilometersandiscomposedof282substationswiththevoltageof5oOkV,22OkV,l1okV,35kVandlOkVnow.Thedistrictcontrolcenter(DCC)isinchargeofdispatchingalIthetransmissionlinesandequipmentwiththevoltageofllOkV,35kV,andpartof22okV.Therearel5subcontroIcenterswhichareinchargeofdispatchingthedistributionlinesandequipmentwiththevoltageoflok…     

First-principles prediction of the magnetism of 4f rare-earth-metal-doped wurtzite zinc oxide

Electronic structure and magnetic properties of wurtzite ZnO semiconductor doped with rare earth （RE=La, Ce, Pr, Pm, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm and Yb） atoms were studied using spin-polarized density functional theory based on the full-potential linear augmented plane wave （FP-LAPW） method as implemented in the Wien2k code. In this approach the generalized gradient approximation （GGA） was used for the exchange-correlation （XC） potential. Our results showed that the substitution of RE ions in ZnO induced spins polarized localized states in the band gap. Moreover, the studied DMSs compounds retained half metallicity at dopant concentration x=0.625%for most of the studied elements, with 100%spin polarization at the Fermi level （EF）. The total magnetic moments of these compounds existed due to RE 4f states present at EF, while small induced magnetic moments existed on other non-magnetic atoms as well. Finally, the energy difference between far and near configurations was investigated. It was found that the room temperature ferromagnetism was possible for RE-doped ZnO at near configuration. Since the RE-RE separation was long enough （far configuration） for magnetic coupling, the system became paramagnetic or antiferromagnetic ground state.     

How to select appropriate measures for reductions in negative environmental impact? Testing a screening method on a regional energy system

The aim of this study is to develop a method that allows selecting appropriate measures for reductions in negative environmental impacts on a regional energy system. In this paper a sophisticated screening method based on theoretical and practical basics of decision-making is proposed. The proposed method is applied and tested on the energy system of a typical rural middle-sized region in Latvia. The starting point for energy system analysis was evaluation of DSM (demand side management) options but later authors chose to include also primary energy to evaluate the whole regional energy system. The proposed method foresees different aspects: not only technical and economical possibilities, but also political and social factors that are very important in the decision-making process are taken into account.     

地区电网新一代SCADA/EMS/DMS/MIS综合自动化系统

电网自动化正面临信息技术蓬勃发展和电网管理机制的变革时期。本文在介绍电网调度自动化发展过程的基础上 ,就新一代地区电网综合自动化系统的开放性、数据库管理系统、支撑平台、即插即用、网络技术、因特网技术等主要特征进行了描述 ,并分析了各项自动化装置和系统的主要功能 ,提出了新一代地区电网综合自动化系统的组成形式。     

Polyacrylonitrile-based nanofibers—A state-of-the-art review

Polyacrylonitrile (PAN), a well-known polymer with good stability and mechanical properties, has been widely used in producing carbon nanofibers (CNFs) as these have attracted much recent attention due to their excellent characteristics, such as spinnability, environmentally benign nature and commercial viability. Among the various precursors to produce CNFs, PAN has been extensively studied due to its high carbon yield and flexibility for tailoring the structure of the final CNFs as well as the ease of obtaining stabilized products due to the formation of a ladder structure via nitrile polymerization. In view of this, they have applications in areas such as electronics, tissue engineering, membrane filtration and high performance composites. This review presents various combinations of PAN and PAN-based precursors in producing CNFs from the PAN homopolymer or its modified precursors, copolymers, blends and various composites. Various modifications of PAN and their future prospects in different scientific and technological disciplines are addressed.