电缆附件局部放电检测技术分析

阐述了电缆附件局部放电产生的原理,综述了电缆附件的局部放电检测技术研究进展及现场应用情况,对各种检测技术的原理进行了分析,为了对比分析各种检测技术的现场实际应用效果,人为在110kV电缆接头制造典型缺陷,同时采用内置式耦合传感器、超高频传感器、电感耦合传感器等进行局部放电检测,并采用软件对检测信号进行分离与识别。     

电-声联合变压器局放检测系统的设计与应用

在UHF传感器、AE传感器、计算机数据处理等局部放电信号采集设备系统的配合下,设计了电-声联合的变压器局部放电在线检测系统。该系统硬件上联合UHF超高频检测和AE超声波检测等优点,软件上采用计算机集成模块化设计,提高了局放测量灵敏度、定位精确性和检测数据运算分析的速率和可靠性。110/10kV工程实测数据表明:电声联合检测系统在变压器局部放电检测与分析方面的设计应用是可行和有效的,能够为变压器状态检修提供大量可信的数据依据。     

HGIS输变电设备状态检修实现方法

<正>一次系统状态检修实现方法利用局部放电检测技术评估HGIS外壳绝缘状态局部放电信号包含丰富的绝缘状态信息,不仅能检测到许多HGIS制造与安装中的缺陷,而且还可能检测出绝缘故障发生的严重程度,在事故的早期阶段提出报警,以便有计划地安排维修,减少设备的损坏,避免事故发生带来的巨大损失HGIS局部放电在线检测目前采取的主要方法有:耦合电容法、化学监测法、光学监测法、超高频法、超     

35kV手车式送电柜放电故障处理

<正>1.故障现象35 kV变电站安装5面JYNI-40.5型送电柜。2012年6月值班员巡视时听到305主变送电柜有异常滋滋声,并伴有放电产生的气味。连续观察几天发现,天气晴好时滋滋声小,阴雨天气时声音加大。2.故障处理根据故障现象,初步判断是柜内元件灰尘过多,在空气湿度较大时,由于绝缘不良产生放电。但夜间闭灯检查柜内元件没有明显的弧光放电现象。为避免造成全厂停产,停电后清扫柜内绝     

机械臂防护压力检测实验系统设计及应用

在机械臂上安装防护装置,避免操作人员接触机械臂时造成人身伤害,在工业安全生产中成为关注焦点。设计一种由BMP180气压传感器、STC89C52单片机控制系统、NRF24L01无线收发模块和LCD1602显示器组成的机械臂防护压力检测实验系统。BMP180气压传感器测量气密性模块内部气压变化;数据通过NRF24L01无线收发模块传送到上位机;上位机接收数据,经STC89C52单片机处理后回传给NRF24L01无线收发模块,进入保护状态后发出警报,并在LCD1602显示器上予以显示,实现人机交互,创建安全的作业环境。重复开展了5次模拟密封环境实验,系统均在设定的压力限值以外实现了报警,验证了系统设计的可行性,为将实验系统移植到真实的机械臂提供了实验方案和数据支持。     

微生物除油技术在高浊度油田黑水冲击下的应用实践

分析了FX油田污水处理中存在的问题,开展污水生化处理技术研究,分离纯化除油菌剂并在现场开展生化系统小试、现场工业应用。现场使用中成功经受住数次浊度大于2000NTU的污水冲击,生化系统投产后处理效果稳定,系统出水含油小于0.7mg/L,颗粒数下降90%,COD小于80mg/L,低于国家二级排放标准;同时也达到区块注水配注要求,日注水量大于110m3,注水压力下降2MPa。     

铜铝过渡线夹在电力设备上的应用

<正>1.问题及分析2012年2月,栾川龙宇钼业有限公司35kV变电站1#主变压器高压侧B相绝缘瓷瓶处铜铝过渡线夹(SLG-4型闪光焊对焊式,以下简称线夹)断裂,并与C相惯性搭接,造成停电4h。技术人员现场实测线夹断口厚度为5.2mm,国家标准厚度为6.3mm。观察线夹断口周围均为新断痕迹,从断裂处查看线夹内部有旧伤。由于线夹此前也多次出现断裂且断裂部位均在铜铝焊接部位。2.线夹断裂原因     

高效液相色谱法测定淡水鱼中抗生素残留量

抗生素富集于鱼体内,通过食物链对人类健康构成危害。通过对高效液相色谱仪的检测波长、流动相及流速、提取方法等几方面的优化,使用Spherisorb C₁₈ 柱,以V(乙腈)∶V(磷酸二氢钠)(EDTA的浓度为0.001mol/L)=28∶72作为流动相,在355nm的检测波长下,成功地进行了人工饲养淡水鱼体内的四环素、金霉素、土霉素等残留物的定量检测,平均回收率约为98.0%,平均相对标准偏差约为4.63%。     

β-D-半乳糖苷酶活性测定方法的研究

应用分光光度计建立一种简便检测β D 半乳糖苷酶(GAL)活性的方法。酶反应条件研究表明,在总体积为1mL的0.1mol/L柠檬酸反应缓冲体系(pH值为4.5)中含0.8μmol的底物邻硝基苯β D 吡喃半乳糖(ONPG),含相当于2mg左右蛋白质的酶提取液,37℃孵育30min后用0.5mol/L碳酸钠1mL终止反应,用紫外分光光度计于405nm波长测定的吸光度值最能反映该酶活性。结果显示,该方法的批内变异系数在3.92%～4.89%之间,批间变异系数为3.8%,均小于5%;在所检测该酶质量浓度范围(1～2.5mg/mL)内线性关系良好,当反应体系的蛋白含量低于0.5mg/mL时,酶活性不能被检出;每组的平均回收率均在95%～105%之间,说明在所检测浓度范围内回收良好。因此,该方法具有稳定性好、灵敏度高、简便易行等特点,适合一般实验室应用。     

农网配电线路分级保护技术应用

<正>技术项目应用背景近些年,随着社会经济的快速发展和国家惠民政策的实施,农村经济已驶入发展快车道,大量家用电器如空调、冰箱等已进入农村百姓家中,农村地区小工业的兴起,更是带动了农村经济的快速增长,也对农村配电网供电能力和供电可靠性提出了更高的要求。安徽阜阳界首供电公司现有10千伏线路77条,总长度1545公里,公变1763台,专变2009台。多年来,界首公司持续加大对农配网线路的农网改造力度,目前10千伏配电线路干线已完成绝缘化改造,已安装真空断路器260台,熔断器155组,10千伏线路平均保护设备为5.4台/条,尽管如此,10千伏农网配电线路整体科技水平仍较低,线路中无     

Divergent patterns of engagement in Internet standardization: Japan,Korea and China

This article analyzes the engagement of Japanese, Korean and Chinese participants in the development of Internet standards at IETF on the basis of four quantitative metrics: attendance, patenting, authorship and leadership. The results are strikingly divergent. Japanese involvement in Internet standardization began early and Japan was, for many years, second only to the U.S. in terms of IETF participation. Though Japanese participation has declined since the early 2000s, Japan remains a major contributor to IETF standardization. Korean involvement in IETF has always been significant, but below the levels of Japan and major European countries. Korean participation in IETF has also declined over the past decade, and has been dominated by one firm, Samsung. Though meaningful Chinese involvement in IETF did not begin until the mid-2000s, it has rapidly expanded in recent years. Today, China is a major player in numerous areas of Internet standardization in terms of three metrics (participation, patenting and leadership), and is rapidly gaining in terms of document authorship as well. Most of China׳s recent IETF involvement can be attributed to Huawei, though other Chinese firms have recently begun to increase their participation in the organization. Thus, contrary to some views that China׳s engagement with standardization is primarily one of indigenous innovation and “catching up”, China׳s experience with IETF demonstrates deliberate and effective engagement with a major Western standards-development organization on its own terms.     

增强Linux系统安全性的措施

L inux系统的安全取决于系统管理员如何来管理它。本文探讨了一系列可以增强安全性的技巧与策略 ,包括 :系统安装原则、BIOS安全、口令安全策略、设计帐户自动注销功能、文件系统和日志安全策略、使用 SSH及 TCP-WRAPPERS,隐藏系统信息、删除所有特殊帐户、关闭控制台程序、限制系统中的 SUID/ SGID程序等。本文最后向 L inux系统管理员提出了一些安全管理方面的建议     

Whose Image is it Anyway?: Some Considerations of the Curricular Importance of Subject Image in Secondary School Design and Technology Education

This paper explores the idea that a sense of school subject image is a necessary feature of curriculum management and a potent force for change. The discussion centres on the view that all school subjects have an image and that if those intimately involved with the subject do not control the image then someone else does! In such circumstances the image is the product of past encounters and old euphemisms and is unlikely to hold the changed realities.The UK developments in Design and Technology education (the term Design and Technology is used to denote the school subject defined under this heading by the UK National Curriculum, 1995) have created something of an image problem which has interesting international parallels. Some of these problems are due to clearly discernible internal tensions and an ambiguous relationship with other subject areas.Through greater attention to subject image internal controversies might be acknowledged and resolved, relationships with other subject areas can be more meaningfully understood and practitioners can be helped to make sense of curriculum change.     

快速成形技术的应用及热点分析

基于快速成形技术的原理,展示了快速成形技术在快速模具制造、金属零件直接成形、反求工程等领域的广泛应用,总结了快速成形制造技术研究的热点,即研发新材料和新设备、提高成形精度、建立RPM的反求工程系统、建立成形技术的统一标准和扩大成形技术的应用领域。     

CIS与现代企业管理美学

概括性介绍了 ＣＩＳ（Ｃｏｒｐｏｒａｔｅ Ｉｄｅｎｔｉｔｙ Ｓｙｓｔｅｍ）的三大基本组成，并阐述了它与现代企业管理密不可分的相互联系及所处的举足轻重的地位，指出导入ＣＩＳ是现代企业谋求发展的重要手段。     

HSE走进中国石油

企业管理水平的好坏直接影响着企业的经济效益,运用HSE管理能提高企业管理水平,HSE管理模式将健康,安全,环境三者视为一个有机的整体。HSE管理认为人的安全是第一位的,人是创造财富的原动力,是企业的最大财产,HSE管理体系强调的是“蝴蝶效应”。     

Diffusion and usage of public e-services in Europe: An assessment of country level indicators and drivers

We analyze the state of the art of indicators on e-government, e-health, e-procurement and e-participation. We survey the main methodological properties of these indicators, and highlight their heuristic potential. Further, we address empirically the issue of the explanation of the availability scores, i.e. how the supply of the various e-services in each country is affected by political, institutional and socio-economic differences, and is followed by actual usage. The econometric analysis uncovers the importance of broadband penetration and higher education as drivers for most of the types of e-services and users (citizens and businesses). Moreover, a corruption-free and agile public sector proves to be an important pre-condition for more effective supply and usage. Despite data limitations and the complexity of the underlying diffusion phenomena, our study is the first truly longitudinal contribution aimed at disentangling the common drivers of such an important phenomenon – the e-services availability and usage across European countries. As such, this work appears useful to inform the policy debate and practice, in a phase characterized by a prospective reorientation of the public e-services provision and policy agenda.     

一种高精度的频率标准比对系统

频率标准源可以提供精确的标准频率,在测定频率标准源的各项性能指标时,要求测试系统必须具有很高的比对精度。所设计的频率标准比对系统采取多级倍频 混频方式使频率偏差逐级扩大后再测量,从而避免了直接进行高次倍频的困难,提高了测量精度,可以对高精度的频率标准的准确度、长短期频率稳定度进行快速测量,是一种高精度时畴参数测量系统。     

Material power and normative conflict in global and local agrifood governance: The lessons of ‘Golden Rice’ in India

This special section aims to investigate the interaction of global and local forces in shaping agrifood governance. It starts from the recognition that a multitude of actors and norms shape today’s agrifood system. The resulting opaqueness of the systems makes it extremely difficult to understand and explain processes and outcomes of agrifood governance. Given the sustainability challenges facing the agrifood system, improvements in our understanding of what the interaction of global and local actors and norms means on the ground are urgently needed, however. The section, therefore, analyses agrifood governance in India across a selected group of cases. It does so by employing a systematic framework emphasizing the material and ideational dimensions of power and their interaction. The section has chosen India as the setting in which to analyze this interaction due to the crucial role the food demand and supply of this rising power plays in today’s agrifood system. This article provides the special sections’ analytical framework, which uses the interplay of material and ideational dimensions of power as a focal lens. In addition, the article applies this framework to an empirical study of the political conflict around GMO foods in India, specifically the case of ‘Golden Rice’.     

蒸汽热量计量应用的探析

研究了石油化工企业的燕汽计量情况,着重对蒸汽热量计量的合理性进行了分析,阐述了蒸汽热量计量的依据及计算方法,以及蒸气热量计量对节能降耗的重要意义.