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211.
公益性地质勘查工作与商业性地质勘查工作分开运行是社会主义市场经济体制下地质勘查工作改革的核心内容,它既是市场经济国家的惯例,也是我国地质勘查工作二十多年改革实践经验的总结,已经越来越为人们所认识。 相似文献
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国家基础地理信息数据库在西部地区县(市)挂图项目中的应用及技术分析 总被引:1,自引:1,他引:0
西部地区县 (市 )挂图工程是以国家测绘局现有的基础地理信息数据库、高分辨率卫星影像数据及其他多种测绘资料为基础 ,采用基于地理信息系统的全数字计算机桌面制图新工艺 ,设计制作科学性强、艺术性高、制作精良的高技术地图产品 ,充分展现地图学理论、制作技术与我国经济发展的水平。本文以分析西部地区县 (市 )挂图项目中的国家基础地理信息数据库的应用范围及数据适宜性评价为基础 ,提出了数据库应用于地图制图的方案 ,总结了若干技术问题及方法。 相似文献
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Long-term contamination of the marine environment surrounding a lead smelter offered a unique opportunity to examine how pollutants might have acted to alter genetic characteristics of populations of organisms in the receiving system. This study used random amplified polymorphic DNA analysis to compare the genetic diversity of populations of the prawn, Leander intermedius, and the isopod, Platynympha longicaudata from the smelter discharge site with reference populations. The genetic diversity of the prawn population from the smelter discharge site (Port Pirie) was lower than that found in one reference population, and not significantly different from the other two reference populations. Genetic diversity of the Port Pirie population of isopods was found to be significantly lower than that of all reference populations. Prawns and isopods were also exposed to metal mixtures in the laboratory in a similar ratio to that found in seston near the smelter effluent discharge site. Both pre-exposed and reference populations of prawns tolerated elevated levels of metals and exhibited no significant difference in response. This contrasted with the isopods, with the pre-exposed isopod population showing greater tolerance to elevated metal levels compared with the reference population. These results highlight the need to include a number of reference populations for comparative purposes in genetic diversity studies, and the need to assess the influence of pollution on the genetic diversity of more than one species if genetic diversity analyses are to be used to gauge remediation success. 相似文献
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Li D Dong M Shim WJ Hong SH Oh JR Yim UH Jeung JH Kanan N Kim ES Cho SR 《Marine pollution bulletin》2005,51(8-12):966-974
In order to investigate spatial and temporal distribution of organic pollutants in the Saemangeum Bay, organophosphorus pesticides (10), alkylphenols (8), chlorophenols (2), bisphenol A were analyzed from the surface seawater taken in 2002–2003. Most of the analytes were not detected in all stations except nonylphenol and S-benzyl-O,O-di-isopropyl phosphorothioate (IBP). Concentrations of nonylphenol and IBP ranged from ND to 298 ng/l and from ND to 1840 ng/l, respectively. The high levels of nonylphenol and IBP were found in the estuary areas of Mangyeong and Dongjin River. The levels of nonylphenol and IBP in surface seawater varied through seasons and the high levels of nonylphenol and IBP were in summer season (August). Based on real time monitoring of IBP and on correlation between concentrations of target compounds and contents of salinity in seawater, physical mixing and diffusion of seawater were found to be the major factors that affect the spatial distribution of IBP and nonylphenol in the Saemangeum Bay environment. 相似文献
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文章以攀枝花市钒钛磁铁矿区、龙门山中段煤磷矿区、新康石棉矿区为例,从矿山地质环境概况,矿山主要地质灾害,矿山地质环境分区等入手,全面分析了四川省矿山地质环境现状及开发利用对生态地质环境的影响和破坏,存在的主要环境地质问题及危害。并提出了矿山生态地质环境恢复与重建的建议。 相似文献