Influence of Units and Assemble on DC Flashover Voltage of Iced Insulator Strings at High Altitude Districts

Based on artificial tests of iced DC XZP-210 insulator strings carried out in the artificial climate chamber, the authors analyze the effects of units and assemble on the DC flashover voltage of iced insulator strings at high altitude districts. The test results show that the relationship between the DC icing flashover voltage and the insulator units is seemly linear with the increase of altitude or pollution level, although the linear relation is not obvious at the low altitude or pollution level. There is influence of the assembled form on icing flashover voltages, the flashover voltage of the horizontal string of iced insulators is highest while that of the vertical string is lowest. For various assembled forms, the effects of the air pressure on the flashover voltage of the horizontal string are most obvious.     

Numerical Simulation of Dynamic Response of Suspension Insulator String

Finite element method is applied to analyze the windage of suspension insulator strings under dynamic wind loads. The dynamic response of a suspension insulator string of 500 kV high voltage transmission line is numerically simulated with ABAQUS software, and results demonstrate that the windage angle of suspension insulator string is larger than that calculated by the conventional design code, which might be one of the main reasons of the frequently happened windage flashover accidents.     

STUDY OF SURFACE AC FLASHING PROCESS OF ICED INSQLATORS

From the testing results in the artificial climate room in Chongqing University, this paper discribes the AC flashover process of cylindoric insulators and suspensive ones, and presents the relations between iced insulators AC flashover processes and its leakage current.     

Analysis of fast optimization algorithm for inverse detecting faulty insulators

In order to improve the computational efficiency of the insulator electric field inverse problem, the fast multi-pole method has been introduced to the traditional simulation charge method. Tikhonov regularization is used to process the ill-posed characteristic of inverse problem solution caused by the interference. Newton method is used to search the optimum solution, and then the actual field source parameters of insulators and the practical voltage distribution on the surface of the insulators can be obtained. The fast optimization algorithm has been verified in point charge model. And 110 kV insulator string is carried out to demonstrate that the fast optimization algorithm is much faster and more efficient than traditional method.     

Optimization algorithm for forward problem with electric fields of defective insulator

The defective insulator can be detected by measuring electric field, however, the electric field calculation accuracy of the insulator strings is low. Charge simulation method (CSM), which is optimized by genetic algorithm (GA), is adopted to calculate high voltage electrostatic field. The optimal method principle and feasibility analysis is given. The objective function and optimization model of electric field distribution around insulator strings are constructed and analyzed. The results of calculation and analysis demonstrate that adopting the potential of check points near insulator strings as objective function and using GA to optimize the charge of simulation charge, better performance can be achieved for improving ability of global optimization, calculating precision, searching speed, simulating precision of CSM and accuracy of diagnosing defective insulator in the insulator strings.     

Calculation and Measurement of Electric Field along Polluted Cylindrical Insulator

In this paper,the electrical field distribution along the polluted cylindrical insu-lator before a nd after the local a re appea rs is calculated with the optim lzed pa rtially cha rge simula-tinn method and measured with the pockels device. Based on the calculating and measuring results,the in fluen ce of the electric field distri bu tion on the propagation of local a re in the flashover ofcyIlndrical insufator under various conditions is analyzed systematieally.     

Research on Lightning Intruded Wave for 500 kV Substations

The study on overvoltage for 500 kV substation caused by lightning intruded wave is presented. In this paper, we calculate by using electromagnetic transient program (EMTP) and combine substation with incoming lines ,so some influence factors can be considered such as impulse voltage second characteristic of insulator strings, lightning stroke point on the incoming lines and impulse grounding resistance of towers. The results show that the method is close to the practice and some factors of incoming lines are important to overvoltage.     

复合绝缘子伞裙老化状态检测的单边核磁共振传感器

对复合绝缘子伞裙老化状态的评估,关系到电力系统的安全稳定运行。为了实现在工程现场对复合绝缘子伞裙的无损检测,提出了一种便携式单边核磁共振传感器的设计方案。对静态磁场的均匀度和射频线圈进行了优化,以获得较高的信噪比。以110 kV等级下不同运行年份的绝缘子为样品进行测量,使用CPMG序列对样品进行激励;采用单指数拟合和反拉普拉斯变换对核磁共振横向弛豫回波信号进行处理。结果表明,随着复合绝缘子运行时间的增加,其等效横向弛豫时间减小。因此,这种便携式单边核磁共振传感器有望用于复合绝缘子伞裙老化程度的定量分析。     

重庆农村黑臭水体水质及底泥氮磷污染分析

对84个重庆市农村黑臭水体水质和底泥氮磷的监测数据进行统计及相关性分析,并利用综合污染指数法和有机指数法对水质和底泥污染状况进行评价。结果表明,87%的黑臭水体水质存在不同程度的氮磷污染,且50%的水体同时存在氮磷超标,河沟、沟渠较塘氮污染更为严重;底泥均受总氮、有机氮、总磷污染,70.2%的底泥存在有机污染。水质中总磷、总氮、氨氮3个指标之间存在显著正相关,底泥中有机质、总氮、总磷之间不存在显著相关关系。底泥中总磷与水质中总磷存在显著正相关关系,但相关性较弱,底泥中全氮与水质中总氮不存在显著相关关系。总体上重庆市农村黑臭水体氮磷污染以外源污染为主。     

Analyze the Present Status in the Calculation Methods of Lightning Protection Performance for Transmission Line

Lightning is the main reason that endangers transmission line working safety and reliabilty today. The theory and characteristic of methods that not only estimate the lightning performance for back strike such as standard method, traveling wave method, Monte Carlo technique, treeing fault method, EMTP and so on but also for the shielding failure such as standard method, EGM, leader progression model and so on are summarized. The criterion of flashover for insulators is referred simply, furthermore, it gives the opinion that the development of research for the future.     

威海近海人工鱼礁区沉积环境要素的时空分布与沉积物质量评价

为了解威海近海人工鱼礁区的沉积环境质量,对该海域表层沉积物中的沉积要素的含量进行了分析,并对其进行污染评价。根据2011年11月,2012年4月、6月、8月、11月和2013年6月、8月共7个航次沉积环境要素调查资料,分析了威海近海人工鱼礁区表层沉积物中总氮、总磷、有机碳和硫化物含量的分布特征,并采用单因子污染指数法和内梅罗污染指数法对沉积物质量进行了评价。结果表明：研究海域表层沉积物中总氮、总磷、有机碳和硫化物的含量均较低,且有机碳和硫化物的含量均符合GB 18668—2002《海洋沉积物质量》中的第一类标准,并呈现出明显的月际变化。单因子污染指数分析表明硫化物和有机碳未对研究海域沉积物产生污染。内梅罗污染指数分析海域沉积物质量的结果表明,研究海域沉积物质量等级为Ⅰ级,且鱼礁区和对照区表层沉积物质量无显著差别。     

污染土地修复工程技术及发展趋势

近年来,中国土地污染状况日益凸显,加剧了土地资源供需矛盾,耕地土壤污染给农民带来了经济利益和健康利益的双重损害。为缓解矛盾,保护粮食安全,保证耕地红线,增加建设用地,如何利用工程技术手段将污染土地变为可利用土地显得尤为重要。通过文献资料法,结合多年来污染土地治理修复的工程技术经验,对污染土地修复工程技术要点进行了探讨和总结,主要介绍中国土壤污染发展现状,以及如何将污染土地变为可利用土地,最后展望了中国污染土地修复工程技术的发展趋势。该研究为提出适合中国国情和符合地区特点的土壤污染修复技术奠定了理论基础,同时为国家粮食安全、生态文明建设提供技术支撑。     

哈尔滨市西郊菜地土壤重金属污染评价

本文以哈尔滨市西郊菜地土壤为研究对象,经过野外调查和室内分析对哈尔滨市西郊菜地土壤的理化性质,重金属的含量及空间分异性进行研究。采用单因子和综合因子指数法对土壤中重金属的污染现状进行评价。结果表明：哈尔滨市西郊菜地土壤未受到重金属污染,土壤尚清洁,污染未超过警戒线。     

北京密云某养殖场雷电灾害事故分析与对策

雷电灾害事故分析有助于更好地掌握雷击途径和方式,认识雷电致灾规律,从而采取更有效的防护措施。针对2014年7月1日北京市密云县西田各庄镇某养殖场发生的雷电灾害事故,统计分析雷击时间段内该区域闪电定位资料;根据滚球法判断养殖场是否在直击雷保护范围内,计算牲畜位置处跨步电压和养殖棚雷电静电感应电压。通过逐项计算和分析,结果表明：牲畜遭旁侧闪络和接触电压致死。雷电的静电感应在金属棚上产生高电压,由于金属棚的支撑钢架结构未做接地,感应电荷释放通道不顺畅,与地面存在电位差,发生旁侧闪络,以及当牲畜接触到钢结构后,高电位通过牲畜向地面释放,致使牲畜死亡。最后提出了对应的防护措施和方法,减少或避免以后类似雷电灾害事故的发生。     

Application of Micronucleus Technique in Testing River Pollution in the Qinhuang River,Binzhou City

To figure out water pollution of the Qinhuang River in Binzhou City,broad bean root-tip micronucleus technique was applied to test water quality,water sample from different sampling points was taken to detect the contamination of broad bean root tips,so as to reflect water pollution using the pol ution indexes.The results showed that water in the Qinhuang River was polluted in different degrees,and water pollution grew more serious from the upper to the lower reaches.Water pollution sources include domestic sewage and solid waste,thus pollution discharge into the river must be strictly controlled to restore the polluted water and the ecological functions of waterscapes.     

Evaluation and Analysis of Bacteria Pollution in Dwelling Indoor Air

Tests and study were carried out on indoor air bacteria pollution in dwelling house inChongqing city. Based on the data of measured bacteria concentration of the indoor air,the reasons for indoor air pollution were analyzed. Ith was found that the bacteria seriously polluted the indoor air. The main factors influencing the indoor air bacteria pollution are moisture, natural ventilation and lighting conditions. The construction forms and decoration of the dwelling house are the secondary reasons for indoor air bacteria pollution. Measures and suggestions of preventing the indoor air bacteria pollution and improving the indoor air quality and environmental quality were presented.     

中、轻度重金属污染农田的特征及治理

文章从环境保护部和国土资源部发布的《全国土壤污染状况调查公报》入手,指出中国耕地的重金属污染情况严重,但大部分受污染耕地都还处于中度或轻度污染程度。笔者概括归纳了与重度污染农田相比,中轻度污染农田的3个特点：仍然承载着农业生产的功能;危害性比较隐蔽;危害性常常被低估。文章结合当前的重金属污染修复技术,综述了低累积作物品种筛选的基础、取得的成果;常用的无机型、有机型、微生物型钝化剂及使用效果。提出针对中轻度重金属污染农田的2个治理策略：种植低累积、耐重金属的农作物品种;原位钝化,降低重金属的有效性。最后,笔者提出今后在中轻度重金属污染农田修复领域的一些发展方向。     

污染农田土壤的治理技术研究概述

概述了由于农时操作过程中用污水灌溉、不合理施用化学肥料、化学农药，以及矿区排污等途径造成农田土壤遭受重金属、放射性物质、硝酸盐以及有机氯残留等污染。通过种植超积累植物（包括农作物的某些品种及某些野生植物）或者通过有益微生物处理土壤、拌种等、采用有机酸、石灰等化学物质和多种有机物质等不同途径，对污染的土壤进行治理，均可收到良好的净化改良效果。同时分析了植物修复的应用前景以及保证效果的调控原则，并强调综合技术合理搭配应用收效会更好。     

中国绿色食品生产面临的环境问题及其对策研究

在提出绿色食品概念的基础上,对绿色食品的产地环境要求进行了概述。同时,着眼于工业“三废”污染、化学肥料农药的过量使用、畜禽养殖业污染和酸雨对农业生态环境的影响现状,分析了绿色食品生产所面临的环境问题,并提出了相应的对策措施。