降阻剂在接地系统的应用

随着现代化建设及科学技术的发展 ,大量的现代设施对接地技术的要求也越来越高 ,相反地对接地电阻的阻值要求越来越低。接地系统的新成员—降阻剂 ,即在电气接地工程中起到了重要的作用。1　原　理1 1　降阻剂的配方降阻剂由电解质、防腐剂、固化剂、润滑剂及填充材料组成。1     

湛江地区土壤中防雷接地体的腐蚀

在湛江临海地区研究防雷接地体在自然界的土壤中腐蚀的行为和规律,综合失重分析、腐蚀形貌观察、电化学测试及电偶测试分析,得出接地体在土壤中的非均匀腐蚀情况,提出在防雷工程中应注重接地体局部的腐蚀预防,避免形成电化学腐蚀造成接地体的破坏。     

接地降阻剂的应用探讨

接地是雷电防护工程中重要的环节之一,降阻剂是降低接地电阻值的重要措施。本文分析了接地降阻剂的种类、降阻机理,对如何选择、使用降阻剂及有效发挥降阻剂的降阻效果提出具体意见。     

深圳机场二次雷达站防雷地网整改工程设计分析

通过对深圳机场二次雷达站地网整改工程设计施工过程进行分析,采用增设非金属接地模块、在地网中释放长效降阻剂等降阻措施相结合的方式,最终测试结果达到了设计要求;给防雷接地设计施工人员提供一些经验参考。     

防雷接地体性能改善及接地电阻分析计算

结合雷电防护工作中的经验和实例,分析防雷接地体的特性.结果表明:降低接地电阻,主要是通过降低接地体的接触电阻和散流电阻;增加接地体所围面积对接地电阻的减少有利;应充分考虑复合接地体形状和接地网内屏蔽效应对接地电阻的影响;接地体周围的土质、埋设深度和季节变化都影响土壤电阻率.接地极沿接地体网边缘设置,网内接地极要稀疏布设.接地极的长度一般不相等,常用接地体埋设深度在1.5～3.5 m之间,北方地区在冻土层以下.可采用性能稳定的降阻剂和在接地体周围更换土壤电阻率低的土质,要使接地电阻达到要求的同时减少成本.     

降低接地电阻的方法探讨

文章首先简述了接地的概念和作用以及降低接地电阻的意义所在,其次总结了降低接地电阻的各种方法,如通过影响接地体附近土壤的电阻率,使用降阻剂等,同时接地电阻的大小也和接地体的形式变化,材料选择,埋设方式等有着密切的关系。最后通过几个实例说明了如何根据系统要求和实际情况来选择合适的降低接地电阻的方法。     

新型接地体与化学降阻剂的应用

介绍了新型接地体与化学长效降阻剂的结构、特性及其在地网施工中根据不同地理环境，不同土壤电阻率，如何正确使用该产品的方法。     

化工企业接地装置的腐蚀问题

<正>1引言在对一些化工企业的常规防雷检测中,经常会出现接地阻值超标甚至无穷大,通过检查分析,发现是由接地装置被腐蚀甚至断裂造成的。化工企业接地装置长期处于阴暗潮湿并且含有各种酸、碱、盐等化学成分的环境中,运行环境恶劣,极易发生腐蚀[1]。而由于其属于隐蔽工程,又无监视装置,遭受长期腐蚀而不易察觉。发生腐蚀后,钢材会变薄、变脆,截面积变小,甚至最终发生断裂现象。长期腐蚀缩短接地装置的使用年限,引发接地网内部及接地线与接地网连接处的断裂。腐蚀产物     

防雷接地系统在复杂地质环境下施工技术的探讨

通过对处于多石岩山区的110kV总降接地项目采取深井钻孔(加施放降阻剂),电解离子接地极、放热焊接等技术的实施,实测各深井及离子接地极接地电阻,通过理论和实测数据分析,得出一些重要的结论.     

降阻剂在防雷接地工程中的应用

从防雷接地工程设计与安装实践出发，简要介绍了降阻剂的降阻原理，归纳并分析了在使用降阻剂中存在的若干具体问题；针对这些问题，重点论述了合理选择降阻剂应考虑的五个因素，同时指出了正确使用降阻剂应注意的三大问题。     

加强业务管理提高测报质量

我局从1999～2003年,测报工作连续4年未出现错情,在此期间共有1个250个班,9个百班无错通过上级业务部门验收.在仪器保管、使用、维护上符合要求,对外报送的各种表、簿都能做好出门合格.     

Addressing the necessity of the registration of the effects of causal mechanics in the example of a simple barotropic model of the atmosphere

Summary Considering the effects of causal mechanics on geophysical problems enables us to explain a number of phenomena, which cannot be explained from conventional positions. This paper shows that the introduction of the force of causality in a simple barotropic hydrodynamic model of weather forecasts results in the outcomes, which, on the one hand, can not be described from the positions of classical hydro-thermodynamics, whilst on the other hand, exist in nature.     

Modeling the evolution of the family of Mediterranean cyclones using the regional model of the atmosphere

Due to the complex orography and the presence of the moisture-saturated air, the Mediterranean region is characterized by the increased baroclinic and convective instability, that leads to the sudden cyclogenesis and the formation of dangerous weather phenomena. The results are given of the investigation of formation mechanisms of Mediterranean cyclones, peculiarities of stages of their evolution and dynamical processes, which occur throughout the atmosphere, using the regional numerical ETA model of the atmosphere by the example of individual cases of the cyclogenesis over the Mediterranean Sea. It is revealed that the cold Arctic air outbreak (the intrusion of the cold Arctic air) to the south of the Western Europe, leading to the formation of the areas of the baroclinic instability and the increased moisture content of the air in the area of the vortex origin, favors the cyclogenesis. The use of the vertical coordinate η in the model enabled to compute more precisely the vertical wind speed, therefore, the influence of the orography on the moisture content and precipitation increase became pronounced. The transformation of the structure of meteorological fields in the course of the development of vortexes is considered. The computation of the helicity is made, and it is shown that this characteristic can be one of the earliest predictors of cyclogenesis.     

流场配置及地形对西南低涡形成的动力作用

本文采用定常二层模式讨论较小地形及高、低层流场配置对西南低涡形成的动力作用。指出了西南低涡的形成是与盆地、河谷以及其上气流分层有关的一种定常态.在上、下为西风分层时期,低层的浅薄暖湿西风有利于西南低涡的形成.在上、下为东、西风分层时期,上层浅薄东风亦有利于西南低涡的形成.小型的凸起山脉对西南低涡的形成没有作用.     

Analysis of the Characteristics of the Low-level Jets in the Middle Reaches of the Yangtze River during the Mei-yu Season

Here, we analyze the characteristics and the formation mechanisms of low-level jets(LLJs) in the middle reaches of the Yangtze River during the 2010 mei-yu season using Wuhan station radiosonde data and the fifth generation of the European Centre for Medium-Range Weather Forecasts(ERA5) reanalysis dataset. Our results show that the vertical structure of LLJs is characterized by a predominance of boundary layer jets(BLJs) concentrated at heights of 900–1200 m.The BLJs occur most frequently at 230...     

On the determination of the height of the Ekman boundary layer

The heighth of the Ekman turbulent boundary layer determined by the momentum flux profile is estimated with the aid of considerations of similarity and an analysis of the dynamic equations. Asymptotic formulae have been obtained showing that, with increasing instability,h increases as ¦¦^1/2 (where is the non-dimensional stratification parameter); with increasing stability, on the other hand,h decreases as ^–1/2. For comparison, a simple estimate of the boundary-layer heighth _u determined by the velocity profile is given. As is shown, in unstable stratification,h _u behaves asymptotically as ¦¦^–1, i.e., in a manner entirely different from that ofh .     

阴山山脉对内蒙古中部地区气象要素影响初探

文章选用阴山山脉山北乌拉特后旗、白云、达茂旗、苏尼特左旗、化德,山南杭后旗、包头、呼和浩特、察右前旗、兴和1971—2000年气温、降水量、天气现象等资料进行对比分析,得到阴山山脉对内蒙古自治区中部地区气象要素影响初步结论。     

2003年黑龙江省主要灾害性天气及其对作物生长发育和粮食产量的影响

利用40年气温、降水资料和历史上千旱、低温严重的年份与2003年进行对比分析．评估黑龙江省2003年发生的严重灾害的分布范同,灾害程度,及其对主要粮食作物生长发育和产量的影响。得出2003年的灾害是30年未遇的全省性严重灾害年,各种灾害对各种作物都产生了不同程度的影响,受害最重的作物是小麦。     

准两年振荡对大气中微量气体分布的影响

NCAR的包含化学、辐射、动力相互作用的两维模式（SOCRATES）移植回国后进行了初步的模拟试验,用以研究某些对环境问题重要的微量气体的化学、辐射、动力传输过程。在不考虑极地平流层云和气溶胶表面非均相化学等情况下,模式积分多年,计算结果稳定,模拟的风场、温度场显示出正常的季节变化,模拟的微量气体分布与卫星实测资料对照,结果也比较一致。为了探讨热带平流层风场的准两年周期振荡（QBO）对平流层微量气体分布的影响,我们做了QBO强迫的数值试验,即在模式中加入QBO强迫,并与不考虑QBO强迫的模拟结果对比。结果表明,QBO与其相关的次级环流所引起动力输送的变化,使平流层微量气体分布发生变化。     

Quantifying the uncertainty of the annular mode time scale and the role of the stratosphere

The impact of high resolution modern vegetation cover on the West African climate is examined using the International Centre for Theoretical Physics Regional Climate Model implementing the NCAR Community Land Model. Two high resolution 25 km long-term simulations driven by the output from a coarser 50-km resolution simulation are performed for the period 1998–2010. One high resolution simulation uses an earlier and coarser-resolution version of plant functional type distribution and leaf area index, while the other uses a more recent, higher-quality, and finer-resolution version of the data. The results indicate that the new land cover distribution substantially alters the distribution of temperature with warming in Central Nigeria, northern Gulf of Guinea and part of the Sahel due to the replacement of C4 grass with corn; and cooling along the coastlines of the Gulf of Guinea and in Central Africa due to the replacement of C4 grass with tropical broadleaf evergreen trees. Changes in latent heat flux appear to be largely responsible for these temperature changes with a net decrease (increase) in regions of warming (cooling). The improved land cover distribution also results in a wetter monsoon season. The presence of corn tends to favor larger precipitation amounts via more intense events, while the presence of tropical broadleaf evergreen trees tends to favor the occurrence of both more intense and more frequent events. The wetter conditions appear to be sustained via (1) an enhanced soil moisture feedback; and (2) elevated moisture transport due to increased low-level convergence in regions south of 10N where the most substantial land cover differences are present. Overall the changes induced by the improved vegetation cover improve, to some extent, the performance of the high resolution regional climate model in simulating the main West African summer monsoon features.