内蒙古乌达地区地球物理场特征与地下煤火分布     

王卫平  于长春  方迎尧  万建华  肖刚毅  吴成平 《物探与化探》2007,31(6):551-555

以2004年内蒙古乌达地区1:5000大比例尺的直升机航空电磁、磁综合测量资料为基础,结合地面煤田地质、物探、遥感等资料,对内蒙古乌达地区的航空磁场特征、航空电磁场特征与地下煤火分布的关系进行了分析与研究,在综合分析的基础上,建立了该区的地下煤火划分标志,并对该区的地下煤火分布和燃烧状况进行了分析和圈定.  相似文献   

数字发射在航空电磁仪中的应用     

周锡华  熊盛青  张虹  金龙哲 《物探与化探》2007,31(6):564-567

讨论了航空电磁仪工作原理、数字发射机以及数字发射多频的原理,介绍了数字发射在航空电磁仪的应用.航空电磁仪发射机由于采用了最新的数字发射技术,减少了系统的重量、使用更灵活、零漂更小、噪声水平更低,提高了电磁测量系统的技术指标和测量能力.  相似文献   

Vulnerability of groundwater in Quaternary aquifers to organic contaminants: a case study in Wuhan City,China   总被引：5，自引：0，他引：5  

Yanxin Wang  Broder J. Merkel  Yilian Li  Hui Ye  Surong Fu  Dana Ihm 《Environmental Geology》2007,53(3):479-484

More than 30 organic contaminants were detected in shallow groundwaters at Wuhan, the largest city in central China. Seriously contaminated groundwaters were from densely populated, industrial and commercial areas. Abnormal concentrations were found in groundwater from Hankou, downtown Wuhan: trimethylbenzene up to 29 μg/L, tetramethylbenzene up to 866 μg/L, and trichloroethene up to 9.5 μg/L. Benzene, Toluene, Ethylene and Xylene (BTEX) contamination of groundwater is serious and widespread at Wuhan, ranging between 0.14 and 25.0 μg/L. Considering the hydrogeological conditions of most Chinese cities, DRAMIC, a modified version of the widely used DRASTIC model, was proposed by the authors for assessing vulnerability of groundwater to contamination. The factors D, R, A and I in DRAMIC model are the same as in DRASTIC. The factor topography is ignored. The factor soil media is substituted by a new factor aquifer thickness (M) and the factor hydraulic conductivity of the aquifer by a new factor impact of contaminant (C). The equation for determining the DRAMIC Index is: DRAMIC = 5D _R + 3R _R + 4A _R + 2M _R + 5I _R + 1C _R. The calculated DRAMIC Index can be used to identify areas that are more likely to be susceptible to groundwater contamination relative to each other. The higher the DRAMIC Index is, the greater the groundwater pollution potential. Applying DRAMIC, a GIS-based vulnerability map for Wuhan city was prepared. Interestingly, places such as downtown Hankou, where enhanced concentrations of BTEX have been detected, correspond quite well with those with higher DRAMIC ratings.  相似文献   

野外露头沉积学描述计算机辅助系统模型设计     

牛新生  刘刚 《江苏地质》2007,31(4):354-358

野外露头沉积学描述计算机辅助系统的任务是要帮助地质工作者实现野外露头沉积学描述信息的数字化处理,即利用计算机实现方便的数据录入、存储、管理、输出、辅助分析等。从地质模型分析入手,给出了系统的功能模型、模块划分和数据库模型。本系统的特点是实现了有关地质信息标准化采集、管理和处理分析,可为盆地分析、成岩成矿分析和区域地质调查工作提供技术支持。  相似文献   

Stable isotope characteristics and origin of ore-forming fluids in copper-gold-polymetallic deposits within strike-slip pull-apart basin of Weishan-Yongping continental collision orogenic belt, Yunnan Province, China     

Wang Yong  Hou Zengqian  Mo Xuanxue  Dong Fangliu  Bi Xianmei  Zeng Pusheng 《Frontiers of Earth Science》2007,1(3):322-332

More than 140 middle-small sized deposits or minerals are present in the Weishan-Yongping ore concentration area which is located in the southern part of a typical Lanping strike-slip and pull-apart basin. It has plenty of mineral resources derived from the collision between the Indian and Asian plates. The ore-forming fluid system in the Weishan-Yongping ore concentration area can be divided into two subsystems, namely, the Zijinshan subsystem and Gonglang arc subsystem. The ore-forming fluids of Cu, Co deposits in the Gonglang arc fluid subsystem have δD values between −83.8‰ and −69‰, δ¹⁸O values between 4.17‰ and 10.45‰, and δ¹³C values between −13.6‰ and 3.7‰, suggesting that the ore-forming fluids of Cu, Co deposits were derived mainly from magmatic water and partly from formation water. The ore-forming fluids of Au, Pb, Zn, Fe deposits in the Zijinshan subsystem have δD values between −117.4‰ and −76‰, δ¹⁸O values between 5.32‰ and 9.56‰, and Δ¹³C values between −10.07‰ and −1.5‰. The ore-forming fluids of Sb deposits have δD values between −95‰ and −78‰, δ¹⁸O values between 4.5‰ and 32.3‰, and Δ¹³C values between −26.4‰ and −1.9‰. Hence, the ore-forming fluids of the Zijinshan subsystem must have been derived mainly from formation water and partly from magmatic water. Affected by the collision between the Indian and Asian plates, ore-forming fluids in Weishan-Yongping basin migrated considerably from southwest to northeast. At first, the Gonglang arc subsystem with high temperature and high salinity was formed. With the development of the ore-forming fluids, the Zijinshan subsystem with lower temperature and lower salinity was subsequently formed. Translated from Mineral Deposits, 2006, 25(1): 60–70 [译自: 矿床地质]  相似文献   

Study of galvanic interactions between pyrite and chalcopyrite in a flowing system: implications for the environment     

Liu Qing You  Li Heping  Zhou Li 《Environmental Geology》2007,52(1):11-18

When galvanic interactions between pyrite and chalcopyrite occur in solution, pyrite, with the higher rest potential, acts as a cathode and is protected whereas chalcopyrite, with the lower rest potential, acts as an anode and its oxidation is increased. In this work a three-electrode system was used to investigate the corrosion current density and mixed potential of a galvanic cell comprising a pyrite cathode and a chalcopyrite anode in a flowing system. The results showed that with increasing concentration of ferric ion in the solution, with increasing acidity, and with increasing flow rate of the solution, the corrosion current density increased and the mixed potential of the galvanic cell became more positive. These experimental results are of direct significance to the control of environmental pollution in mining activity. By using the galvanic model, mixed potential theory, and the Butler–Volmer equation, the experimental results were explained theoretically.  相似文献   

Jurassic radiolarian-bearing series of Tunisia: biostratigraphy and significance to western Tethys correlations     

Mabrouk Boughdiri  Fabrice Cordey  Houaïda Sallouhi  Kamel Maâlaoui  Amara Masrouhi  Mohamed Soussi 《Swiss Journal of Geoscience》2007,100(3):431-441

  相似文献   

Simulation-optimization approach to assess groundwater availability in Refugio County, TX   总被引：10，自引：0，他引：10  

V. Uddameri  M. Kuchanur 《Environmental Geology》2007,51(6):921-929

Sustainable management of groundwater resources is critical for viable development of semi-arid regions. Refugio County, TX, is predominantly a rural community that is in close proximity to two large urban areas of Corpus Christi and San Antonio. Large-scale water supply projects are being planned to export surplus water available in Refugio County to nearby growing cities. Being a coastal county with several sensitive bays and estuaries, these projects have caused concerns with regard to decreases in freshwater inflows to coastal bodies and raised the possibility of saltwater intrusion. A simulation model characterizing groundwater flow in the shallower unconfined and the deeper semi-confined formations of the Gulf coast aquifer was calibrated and evaluated. The model results were used in conjunction with a mathematical programming scheme to estimate maximum available groundwater in the county. Stakeholder concerns were incorporated as constraints, which included prevention of saltwater intrusion in the aquifer, limiting the amount of allowable drawdown in shallow aquifers, as well as maintaining current flow gradients especially near baseflow-dependent streams and rivers. For the conditions assumed in this study, the model results indicate that roughly 4.93 × 10⁷ m³ of water can be extracted in a typical year. The management model was noted to be very sensitive to the imposed saltwater intrusion constraint.  相似文献   

国内生态环境遥感监测的内容与方法探讨     

陈文惠 《福建地理》2007,(2)

在总结大量实际工作的基础上,就区域生态环境遥感监测的指标与分类系统问题进行了探讨,提出了尽可能与现有的土地利用分类衔接,又较容易进行遥感判读和分类的土地利用分类系统;根据目前国内遥感数据获取和使用情况提出了遥感影像选择、处理以及合成的最佳方案,推荐了通过目视判读和自动分类获得土地利用状况的方法等,以期生态环境遥感监测能真正纳入环保部门常规的监测工作中.  相似文献   

上海城市功能的转型:从全球生产系统角度的透视     

宁越敏  李健 《世界地理研究》2007,16(4):47-54

本文首先回顾了价值链与全球生产系统的研究进展，结合跨国公司最新发展趋势对全球生产系统特征进行了总结；其次以改革开放以来上海对外贸易结构的改变，描述了90年代以来上海在全球生产系统分工中的变化，认为出口产品结构的转型并没有真正改变上海在国际劳动分工中处于低端环节的地位；最后就上海建设世界城市的差距与优势进行了总结，提出全球化发展的外部力量和地方化响应的内部力量将是上海发展世界城市的两个重要驱动力。  相似文献