常规变电站无人值班改造技术方案的探讨

本文通过对常规变电站无人值班改造所包括的保护配置改造、二次接线、监控系统配置等方面进行讨论,从而完成一个成熟方案;该方案能有效应用在实现变电站无人值班改造工程中,并成功投运。     

贵阳电网变电站无人值守改造的研究

本文分析了变电站无人值守改造的技术要点,研究了贵阳电网无人值守变电站的设计与规划,总结了贵阳某220kV变电站无人值守改造的经验。     

试论变电站运行的无人管理模式创新

当前,随着经济的发展,电力工业作为我国经济发展的基础也实现了较大的发展。各种先进的技术被应用至电力系统之中,其中就包括自动化技术。自动化技术应用在变电站之中,使得变电站运行实现了无人值班运行模式,这种模式不仅提高了变电站运行的可靠性,还节省了人力、物力,因此,在变电站中得到了大力的推广。但是这种无人值班模式还需要相匹配的管理方法才能确保变电站的安全生产。本文就对变电站运行的无人管理模式进行探讨,对其存在的问题进行分析,提出采取“集中监控,分区操作”的变电站运行无人管理模式,以提高无人值班变电站的运行效率。     

500kV变电站无人值班建设及相关技术的研究

近几年来,我国各项基础设施建设日臻完善,特别是国家电力工程飞速发展起来,变电站建设项目在各项现代化技术的支撑下为社会创造了极高的价值。从变电站的管理模式来看,无人值班变电站运作模式的提出及应用在一定程度上提高了变电站的整体效能。本文就以500k V无人值班变电站建设为例来对电力系统的现代化管理模式进行论述,探究该领域技术的应用应用能效,并呈现当下变电站集中控制中心的维护及监测系统的运作状况,以期为实践提供有益的借鉴。     

无人值班变电站集中监控的探讨

无人值班变电站是电网发展的一种趋势,利用自动化系统,建立变电站安全集中监控系统。该系统对变电站的安全稳定运行有实际的指导意义,使故障信息能够早期发现,得到及时处理,真正实现了电力系统中无人值班变电站的无人值守。     

关于变电站无人管理模式的具体分析

在现代城市建设中,变电站担负着城市供电的重要职责,其安全稳定运行对保障社会经济发展有着重要的意义。为了满足现代社会电力需求,变电站技术也得到了快速的发展与应用。以无人管理模式技术实现了变电站的无人值守,有效地提高了变电站工作效率的同时避免了人工操作失误等对供电稳定性的影响。本文就变电站无人管理模式进行了简要论述,以此为我国输变电技术发展以及相关推广应用工作奠定基础。     

无人值班变电站的发展与综合自动化系统

当前我国大多数变电站都采取了无人值班的运行管理模式,文章对无人值班变电站发展的几个重要阶段进行了回顾性分析,对变电站综合自动化的特点进行了分析,并对在无人值班变电站的设计和运行中采用综合自动化系统进行了探讨。     

500kV变电站无人值班改造经验

500kV南宁变电站是南方电网首批实现无人值班的超高压变电站之一。结合南宁变电站无人值班改造过程中所遇到的一系列问题及解决方案,对超高压变电站计算机监控系统、保护管理信息系统及其它辅助系统的无人值班改造经验进行了总结归纳,并对提高超高压变电站综合自动化系统的可靠性、规约的标准化,扩大监控范围等方面提出了有益的建议。     

110KV无人值班变电站设计原则的探讨

随着我国经济社会的不断发展,越来越多的变电站被建设,无人值班变电站作为未来变电站的发展趋势,其设计显得尤为重要.为了保持无人值班变电站能够稳定、安全的运行,下面提出一些设计方面的建议.     

无人值班变电站设计探讨

结合湖北省荆门市电业局已建七座无人值班变电站的经验，提出新建及改造无人值班变电站的设计规范设想，供讨论。     

Low doses of a red wine ingredient figh diabetes in mice

Aresearch group led by Prof. ZHAI Qiwei from the Institute for Nutritional Sciences under the CAS Shanghai Institutes for Biological Sciences has discovered that even relatively low doses of resveratrol--a chemical found in the skins of red grapes and in red wine--can improve the sensitivity of mice to the hormone insulin, according to a report in the October,2007 issue of Cell Metabolism. As insulin resistance is often characterized as the most critical factor contributing to the development of Type 2 diabetes, the findings“provide a potential new therapeutic approach for preventing or treating” both conditions, the researchers said.     

Students' Reactions to the Introduction of Videoconferencing for Classroom Instruction

This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.     

Cooler temperatures inductive to locust outbreaks

Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China＇s projected climate warming could decrease the pest＇s numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.     

Exploring Multiplexity: Social Network Structures in a Computer-Supported Distance Learning Class

A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.     

Molecular motor assembly of a biomimetic system

Active biological molecules and functional structures can be fabricated into a bio-mimetic system by using molecular assembly method. Such materials can be used for the drug delivery, disease diagnosis and therapy, and new nanodevice construction.     

To serve and promote science development via innovation

CAS should stick to the principle of rendering service to, and giving impetus for, the development of China＇s science enterprise by making S＆T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party＇s Leading-member Group at CAS, which was held from 7 to 11 January in Beijing.     

The Role of Intermediating Institutions in the Diffusion of Electronic Data Interchange (EDI): How Industry Associations Intervened in Denmark, Finland, and Hong Kong

Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.     

Tracing the origin and early radiation of birds——Paleornithologist ZHOU Zhonghe

With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants."     

The Information Environment and Universal Service

This essay focuses on universal service and the Internet as means to support social and political participation. The emphasis on access to telecommunications systems in conventional approaches to universal service is contrasted with access to content. A model of the information environment is described that accounts for the roles of content and conduit, both of which are necessary conditions to achieve true access. A method is outlined for employing information indicators to observe or measure the information environment.     

How Electronic Publishers are Protecting Against Piracy: Doubts About Technical Systems of Protection

The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.