Origin of abnormal substances discharged from Baozhusi Dam Base, Sichuan, China     

Qian Hui  K. W. F. Howard  Zhang Yiqian  Xi Linping 《Environmental Geology》2005,47(7):1000-1009

Baozhusi reservoir is a large-scale hydropower engineering project in Sichuan Province, China. After drainage wells were drilled in the dam base, white flocculent and black gel substances, accompanied by a rotten-egg odor, were found in some of the drainage water wells. On the basis of a brief introduction of the geological setting in Baozhusi Dam area, the origin of the abnormal substances were analyzed and discussed through the following procedures: (1) the abnormal substances were sampled and their chemical and mineral compositions were analyzed; (2) the origin of drainage waters were determined using the isotope method and well flux measurement results; (3) characteristics of chemical composition of drainage waters were discussed relative to other kinds of waters in the area; (4) process of formation of the abnormal substances were determined using hydrogeochemical methods; (5) laboratory immersion experiment was carried out to verify the conclusions. Results showed that the abnormal substances were formed by interactions between recharging water from the reservoir and dam base rock as well as dam building materials. Among these, the precipitation of calcite and dolomite, the dissolution of calcium hydroxide and anhydrite as well as the reduction of SO₄^–2 to H₂S by organic matter are the most important processes.  相似文献   

关于教育科学中评估问题的注记     

何伍鸣  王柏钧  韩资徽  王力勤 《成都信息工程学院学报》1992,(3)

本文对L·Saaty提出的多目标决策方法进行了分析,结合教育评估实例,指出方法中的某些形式计算,并对有关位置参数的稳健估计作了简单推导和讨论。这种稳健评估方法思想,可供现场进行教育评估参考和应用。  相似文献   

天津滨海新区区域发展过程研究   总被引：6，自引：1，他引：6  

贾艳杰 《地理科学》2002,22(4):408-412

以天津经济新区－滨海新区为例，以1993－2000年相关统计资料为基础，通过其发展过程和影响因素分析，探讨区域发展特点，滨海新区的研究表明，在我国由计划经济向市场经济体制转型时期，小区域发展是一个相当复杂的过程，政府在滨海新区的发展过程中始终扮演重要角色，中央政府通过经济政策创造宏观发展环境，影响区域发展，地方政府是地方发展战略的决策者，通过促进经济增长引导区域发展方向，形成区域特色，地方开发条件是影响区域发展的基本因素，其在开发的初期阶段尤为重要，它是政府发展战略形成和外商投资选择的基础，环渤海城市间的竞争与联合对天津滨海新区的发展亦产生重大影响。  相似文献   

我国灾害遥感的作用、现状及发展     

阎守邕 《遥感学报》1990,(3)

本文从现代遥感技术系统的构成和特点出发,论述了遥感在减灾活动,包括预警、监测、评价和辅助决策中的重要作用。并在回顾我国灾害遥感现状的基础上,提出了今后发展的设想。作者认为:建立实用性的重大自然灾害遥感监测评价技术系统,是今后我国灾害遥感发展的中心环节和主要任务。该系统应包括航天遥感宏观监测系统,航空遥感全天候、实时监测系统,地面灾害及背景监测系统,灾害及背景数据库系统,灾害分析、评价与辅助决策系统以及灾害防治救援通讯指挥系统。  相似文献   

Laboratory simulation of salt weathering processes in arid environments     

R. U. Cooke 《地球表面变化过程与地形》1979,4(4):347-359

The equipment and techniques being used at Bedford College, London to simulate salt weathering processes in deserts are described in the context of a general discussion of the nature of salt weathering processes and approaches to studying them. An experiment based on the equipment and techniques is described: it is designed to test the durability of three building stones in the presence of several different saline solutions under conditions of surface temperature and relative humidity that are considered typical of hot deserts. The experiment, the first of a series, shows that Na₂SO₄ is the most effective of the salts used, and that susceptibility of the rocks to weathering is related to such rock properties as porosity, microporosity and water absorption capacity.  相似文献   

近三百年来承德地区的经济开发过程及其区域特征     

韩茂莉 《地理研究》1996,15(1):50-57

承德地区近三百年开发是在特殊的历史背景下进行的,关内移民大量出关与塞外政治中心─避暑山庄的出现,对这一地区的近代经济开发起了很大的推动作用,本文以避暑山庄的兴衰为线索,论述了在前后两个开发阶段中这一地区的区域特征与经济开发过程,并指出山庄的衰落不仅影响了承德自身的经济发展而且也影响了整个地区的经济地理面貌。  相似文献   

Einfluß der Temperatur auf die Bildung von Magnetit als Zusatzstoff für die Magnetseparation     

P. Kampeis  M. Franzreb  M. Nesovic  S. H. Eberle 《洁净——土壤、空气、水》1997,25(4):173-178

Influence of the Temperature on the Formation of Magnetite as an Additive for Magnetic Separation To investigate the influence of the temperature on the formation of magnetite in aqueous solution, experiments were performed in which ferrous hydroxide was precipitated from oxygen-free ferrous sulfate solution (c₀(Fe) = 5 mmol·dm^?3) and subsequently oxidized with synthetic air. The precipitates so obtained are a mixture of solids whose compositions depend on the temperature and on the rate of aeration. Above all, magnetite, goethite, and δ-FeOOH had been formed. Magnetite occurs at temperatures above about 15 °C, goethite above 35 °C, and δ-FeOOH below about 10 °C. Referring to the thermogravimetric plots and to the relationship between the temperature of formation and the pH measured upon completion of the reaction, it is justified to assume that also sulfate is contained in the precipitates. The values of the magnetic moment of the precipitates, which are crucial in magnetic separation, made evident the dependence on the temperature of formation expected on the basis of solid analyses and confirmed the presence of δ-FeOOH at rather low temperatures. At the rates of aeration applied, it was possible to obtain from about 15 °C on solids having magnetic moments which are sufficient for magnetic separation.  相似文献   

熊耳山北坡拆离断层带地球化学特征及其与金银矿化的关系   总被引：13，自引：1，他引：13  

郭保健  戴塔根 《矿产与地质》1997,11(1):20-25

熊耳山北坡发育一套典型的变质核杂岩构造，区内众多的金银矿床与变质核杂岩关系密切。研究表明，早期拆离断层带内Ａｕ，Ａｇ等成矿元素具有较高的富集系数，拆离断层对区内的缓倾层间破碎带型、陡倾构造蚀变岩型和爆破角砾岩型金银矿化具有不同形式的控制作用  相似文献   

论中国建制镇发展,地域差异及空间演化—兼与“中国反城市化论”者商榷   总被引：15，自引：0，他引：15  

顾朝林 《地理科学》1995,15(3):208-216

  相似文献   

岩溶塌陷地质灾害的评价方法探讨   总被引：2，自引：0，他引：2  

王维理  李文平 《地质灾害与环境保护》2008,19(3):78-81

利用层次分析法确定了岩溶塌陷地质灾害危险性评价指标的权重,并采用综合指数模型计算了岩溶塌陷地质灾害的危险性指数,通过量化的危险性指数分级,划分了岩溶塌陷的危险性大小,这种方法对今后地质灾害危险性评估中岩溶塌陷的评价具有一定指导意义。  相似文献