NaCl在混合溶剂（水-乙醇-丙酮）中热力学性质研究          下载免费PDF全文

王卫东 《盐湖研究》2008,16(4)

应用电导法测定了在303 K时NaC l在混合溶剂(水-乙醇-丙酮)中的活度系数,计算了NaC l在混合溶剂中的相对偏摩尔自由能,讨论了NaC l电解质溶液活度系数及其相对偏摩尔自由能随浓度的变化关系。  相似文献   

几次中强地震前电磁波异常的初步分析   总被引：1，自引：0，他引：1  

王在华  李尚伟 《内陆地震》2010,24(3):215-220

2008年新疆新建轮台、喀什、阿图什3个电磁波观测台站,经过1年多的观测,喀什、阿图什2个台站资料较为连续、可靠。台站400 km范围内的5次5级以上地震前,电磁波具有明显的短临异常特征。阿图什、喀什2个台站电磁波最大值的异常图像虽有一定差异,但均有重复性。阿图什电磁波异常形态为上升—下降的高值变化过程,而喀什电磁波异常形态主要为高值突跳。异常时间一般出现在震前10 d内,具有较好的临震指示意义。  相似文献   

海底电性源频率域CSEM勘探建模及水深影响分析   总被引：4，自引：3，他引：1       下载免费PDF全文

刘长胜  Mark E. Everett  林君  周逢道 《地球物理学报》2010,53(8):1940-1952

为了探索我国海域油气和水合物等高阻目标体CSEM勘探的可行性和方法技术,本文研究了在海水中水平电性源激励下有限水深海洋地电模型的频率域电磁响应,为进一步的1D和3D仿真计算奠定了理论基础.在推导电磁响应公式时,首先给出了各层介质的Lorentz势,然后根据Coulomb势与Lorentz势的关系,得到了各层介质的Coulomb势.各层介质中的电磁场均可以由Lorentz势或者Coulomb势计算得到,但在有限元计算时Coulomb势具有优势.长导线源的电磁场和势函数可以由电偶源的电磁场和势函数沿导线长度积分得到.文中具体给出了海水中水平电偶源和长导线源在海水层的电磁场公式,并根据该公式计算了不同水深环境下海底表面的电磁场分布,分析了海水深度对海底油气储层电磁异常的影响.结果表明,随着水深减小,异常幅度和形态特征发生明显变化.当水深很浅时(如50 m),只有同线方向的E_x和E_z两个电场分量存在明显异常.最后,以两个已知海底油田为例,计算了不同水深环境下可观测到的电场异常,展示了电性源频率域CSEM在海底勘探中(包括浅海环境)的良好应用前景.对于该方法实用化过程中还需进一步解决的问题,文中结尾部分也进行了初步探讨.  相似文献   

地磁感应电流（GIC）的作用与评估   总被引：2，自引：1，他引：2       下载免费PDF全文

马晓冰  Ian J.Ferguson  孔祥儒  Xianghong Wu  闫永利 《地球物理学报》2005,48(6):1282-1287

地磁感应电流（GIC）可能对各种人工长距离导电体造成影响与危害.地磁扰动产生的感应电场的强度与地磁场强度、地下电阻率结构相关，在导电系统内生成的GIC的强度则同时与导电系统的内在结构有关.计算了加拿大Manitoba省三个典型地区在2000年7月15日的一个强烈磁暴期间产生的感应电场.通过对地磁活动性的统计分析，估计加拿大魁北克电网可能经受的最大GIC达每相78A（一年一次）和234A（每十年一次）.  相似文献   

Infrastructure failure interdependencies in extreme events: power outage consequences in the 1998 Ice Storm     

Stephanie E. Chang  Timothy L. McDaniels  Joey Mikawoz  Krista Peterson 《Natural Hazards》2007,41(2):337-358

This paper addresses the problem of interdependent failures of critical infrastructures in disasters. Disruptions to critical infrastructure systems such as electric power or transportation frequently cause major social and economic loss in disasters, both directly and through failures in one system leading to or compounding disruptions in another. Strategic approaches regarding infrastructure failures are needed to guide community mitigation and preparedness efforts. This paper defines and provides a conceptual framework for investigating infrastructure failure interdependencies (IFIs) from the standpoint of societal impacts. In order to identify empirical patterns, a unique database has been developed of IFIs observed in major electric power outage events. This paper presents analysis of this data for a major Canadian disaster, the 1998 Ice Storm that affected the northeastern region of the country. The analysis identifies IFIs due to power outage caused by the storm that are of greatest societal concern. These represent potential foci for effective, targeted pre-disaster mitigation and preparedness efforts. The framework and approach are broadly applicable across a range of natural and human-induced hazards.  相似文献   

Delineation of groundwater zones using lithology and electric tomography in the Khartoum basin, central Sudan     

Mohammed Tahir Hussein  Hussein Salim Awad 《Comptes Rendus Geoscience》2006,338(16):1213-1218

The three towns of Khartoum, Omdurman and Khartoum are located north of the capital of Sudan. This capital has agglomerated to reach more than 7 million inhabitants. The present situation is confronted with a dramatic shortage in freshwater supply. The treatment of surface water from the Nile became costly, particularly in flood season. Thus the authorities turned towards developing groundwater resources. The electric tomography, obtained by the combination of Vertical Electrical Sounding (VES) and well logs, turned out to be very efficient to provide a complete electrical image of the underground from the surface until about 200-m depth. This methodology constitutes a very cheap guide for the evaluation of the quality of groundwater resources in the Khartoum area. To cite this article: M.T. Hussein, H.S. Awad, C. R. Geoscience 338 (2006).  相似文献   

Mapping soil salinity using a combined spectral response index for bare soil and vegetation: A case study in the former lake Texcoco, Mexico   总被引：3，自引：0，他引：3  

N. Fernndez-Buces  C. Siebe  S. Cram  J.L. Palacio 《Journal of Arid Environments》2006,65(4):644-667

Mapping soil salinity is difficult due to its large spatial and temporal variability. Remote sensing is widely used to lower survey costs, but existing studies usually analyze bare soils and make little reference to the halophytic plants and their role as salinity indicators.This paper aims to correlate soil characteristics (electric conductivity in saturation extract (EC_e) and sodium absorption ratio (SAR) with the spectral response of plant species and bare soils, integrating an algorithm to allow multi-scale mapping using remote sensors.Ground radiance was measured on different plant species and bare soils. A Combined Spectral Response Index (COSRI) was calculated for bare soils and vegetation by adjusting the normalized difference vegetation index (NDVI). EC_e and SAR were determined in surface soil samples. Correlation coefficients between COSRI and soil salinity were obtained and a model was adjusted to predict soil salinity. Landsat-ETM and airborne digital images were used to calculate raster maps of COSRI, and EC_e and SAR were estimated using adjusted models. Correlation between COSRI and EC_e and SAR was of −0.885 and −0.857, respectively. Variance accounted for by exponential models for EC_e and SAR was of 82.6% and 75.1%, respectively. It may be concluded that the method is an easy, low-cost procedure to map salt-affected areas.  相似文献   

大气电场,电流多路同步测量的数据实时采集和滚动显示记录系统   总被引：6，自引：5，他引：6  

张广庶  郄秀书 《高原气象》1997,16(2):210-215

阐述了利用微机对大气电场及麦克斯韦电流密度进行实时多路长时间记录、显示的原理，操作方式及编程。在野外观测的基础获得了电场、电流密度的同步数字化资料，实现了电场、电流密度观测记录的自动化、该系统测量信号以模式所形式实时连续滚动显示在ＶＧＡ显示器上、数字化信号实时存储在计算机硬盘上，记录后的数据可再处理，也可再显示。  相似文献