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为了研究某110kv变电站中旧式的110kV高压断路器合闸拒动事故的原因,分析了故障录波,开展了二次故障模拟,微机保护调试,蓄电池组维护等多项试验,最终得出此次事故的主要原因在于缺少对变电站蓄电池组进行日常维护,为了防止类似情况再次出现,总结出了一套较完善的蓄电池组维护方案,并该蓄电池组维护方案推广至公司所有的变电站,为整个电力公司电网安全运行多增加了一份保障。 相似文献
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蓄电池是直流系统中不可缺少的设备,在交流失电的事故状态下,蓄电池应作为变电站的备用能源。这种电源广泛应用于各变电站中。目前公司直流电源所带的蓄电池大多是阀控式密封铅酸蓄电池,因此加强对铅酸蓄电池的维护管理,改善其使用状况,从而有效地延长蓄电池的使用寿命,具有非常重要的意义。本文对铅酸蓄电池的性能指标、运行维护作一介绍,并将这一新技术广泛地应用于本公司电力系统,以确保系统可靠稳定的运行。 相似文献
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本文主要对110kv变电站线路保护越级跳闸事故进行分析,总结了一起线路保护越级跳闸事故,详细阐述了这种事故的原因,并制定有相关防范方法,例如定期维护蓄电池、调控竣工电路、加强监管力度和调试管理力度。 相似文献
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针对一起某110kV变电站10kV线路故障,结合现场一次设备检查情况分析、故障录波分析、调度监控台信号情况分析、二次设备检查情况分析,综合分析得出因蓄电池存在家族性质量问题导致该变电站直流系统故障扩大造成10kV线路烧损,其事故扩大的主要原因为22号蓄电池内部故障安全阀动作,电池开路。在分析该厂商蓄电池家族缺陷特征信息后,提出了下一步处理及预防措施,可为蓄电池设备管理、家族缺陷认定提供参考与借鉴。 相似文献
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文章从变电站蓄电池使用及运行维护情况着手,根据阀控式铅酸蓄电池工作原理及失效机理,分析了变电站蓄电池性能下降的具体原因,并探讨了单只落后蓄电池补充充电装置的设计制作原理及应用效果。 相似文献
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随着国家对新能源的大力扶植,大量的新能源机组逐步投入到系统,虽然部分解决了能源不足的问题,但由于110kV线路侧没有安装压变,重合闸及备自投不具有检无压检同期的功能,为避免非同期合闸事故,110kV线路重合闸及备自投不能正常投入,当110kV进线故障时将造成110kV变电站全停事故。为了保证此类变电站安全稳定运行及对重要负荷可靠供电,由专业技术人员多次分析讨论,最终确定备自投装置投入方案并实施。本文就是一起110kV中压侧带小电源变电站备自投装置投运后的进线线路跳闸备自投动作的事故案例分析,并由此提出正常运行及事故情况下可能存在的一些问题及防范对策。 相似文献
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介绍了智能变电站蓄电池组检测系统中的多路电压电流采集部分,实现了一种蓄电池组实时在线集中监测系统中关于多路电压电流采集的设计。该系统针对变电站的蓄电池组,成功实现了对255路单电压、一路充电电流一路放电电流的采集等功能,大大提高了变电站维护人员的工作效率,消除了监测盲点。 相似文献
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变电站的直流系统是继电保护、安全自动装置和通讯系统的电源,是电网的重要设备,其稳定运行对防止系统破坏性事故的扩大至为重要.变电站的直流系统组成包括直流充电机、直流配电柜及蓄电池组成.目前,应用较为普遍的蓄电池有镉镍蓄电池和铅酸蓄电池两种.虽然阀控蓄电池价格比普通蓄电池的价格高得多,但它以体积小、重量轻、无泄露、无污染、维护工作量小的特点得到广泛的应用. 相似文献
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Marjorie Armstrong-Stassen Margaret Landstrom Ramona Lumpkin 《The Information Society》1998,14(2):153-164
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. 相似文献
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A joint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology his co-workers from Norway US 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 the National Academy of Sciences on September .…… 《中国科学院院刊(英文版)》2008,22(1):6-7
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. 相似文献
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Caroline Haythornthwaite 《The Information Society》2001,17(3):211-226
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. 相似文献
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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. 相似文献
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Puay Tang 《The Information Society》1998,14(1):19-31
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. 相似文献
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Milton Mueller 《The Information Society》2001,17(3):151-163
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP. 相似文献
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Prof. Raymond C.K. Chen a neuropsychologist with the CAS Institute of Psychology has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.…… 《中国科学院院刊(英文版)》2008,22(1):15-15
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology. 相似文献
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《中国科学院院刊(英文版)》2014,(3)
<正>In Xishuangbanna,one of China’s most biodiverse regions,landscape has changed dramatically during the past three decades due to the conversion of tropical rainforest to rubber plantations.In steep areas,terraces are often constructed before planting rubber trees,which causes two important changes in the soil:the destabilization of soil in the bench terraces and the increased vulnerability of unvegetated riser faces to erosion.Few studies have documented the nature and intensity of erosion on bench terraces.Prof.LIU Wenjie and his colleagues from the Xishuangbanna Tropical Botanical Garden(XTBG)conducted a study in Menglun County(21°5′39″N,101°15′55″E),Xishuangbanna to evaluate the influence 相似文献
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Chinese Scientists Use Earth Observation Technologies to Study and Protect Wild Camels 总被引：1，自引：0，他引：1
《中国科学院院刊(英文版)》2014,(3):267-268
<正>Chinese scientists plan to apply Earth Observation technologies to protect the critically endangered wild camels(Camelus ferus).With the help of remote sensing,satellite positioning,geographical information system and wireless sensors networks,they will be able to access the distribution and population of the wild camels and protect their habitats.The project will be carried out by the International Research Center for Wild Camel Conservation,which was jointly established earlier this year by the Institute of Remote Sensing and Digital Earth(RADI)of the Chinese 相似文献
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WANG Sijia 《中国科学院院刊(英文版)》2014,(2):192-194
<正>The Paul Gerson Unna Research Group on Dermatogenomics was founded in October 2012 at the Partner Institute for Computational Biology.The ultimate goal of the group is to understand the biology of skin and skin appendages. 相似文献