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选取广西桂南地区地下热水系统为研究对象,利用氢氧同位素及锶同位素研究手段,对研究区内地下热水中氟的空间分布规律及其控制因素进行研究。结果表明:研究区内地下热水中氟含量变化范围为0.01~17.93mg/L,其中43%地下水样品中氟含量超过饮用水氟骨症临界值1.5mg/L,高氟地下热水的主要水化学类型为Na-HCO3型,水体中氟含量与温度呈明显正相关性;地下热水氢氧同位素特征显示,研究区地下热水的主要来源为大气降水,同时受一定程度蒸发浓缩及水-岩作用影响,地下热水锶同位素特征显示,研究区地下热水水化学组成明显受长石、云母等铝硅酸盐风化及碳酸盐岩溶解影响;对地下热水水化学开展的因子分析结果显示,研究区地下热水系统中影响氟迁移释放的主要因素为萤石的溶解与沉淀过程。 相似文献
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为探究桂南地区含氟地下热水的水文地球化学特征,对桂南地区出露的温泉点和地热钻孔进行了两次调查和水样采集工作,分析了地下热水中各水化学指标、微量元素和氟(F-)含量,并探讨了影响高氟地下热水形成的地质环境因素。结果表明:(1)桂南地区地下热水主要有SO_4-HCO_3-Ca型、HCO_3-Ca型、Cl-Na和SO_4-Na型以及HCO_3-Na型4种水化学类型;(2)地下热水中微量元素Rb、Cs、Li、Sc、SiO_2的含量与水温具有较好的正相关关系,根据地下热水中这几种微量元素的含量可大致确定地热异常区;(3)地下热水中有利于氟富集的条件包括强烈的蒸发作用、降雨淋溶作用、高温、碱性pH值、低Ca~(2+)含量、高Na~+含量。 相似文献
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《安全与环境工程》2021,28(3)
拟建中尼铁路途经西藏萨迦县和拉孜县,地热灾害是拟建中尼铁路工程建设过程中可能遇到的地质工程问题之一。通过计算离子比例系数,绘制Gibbs图、Na-K-Mg三角图和SiO_2溶解度曲线,分析了研究区地下热水的水化学特征及其水文地球化学演化过程的主要控制因素,并根据氢氧同位素数据分析了研究区地下热水的补给来源,基于此对拟建中尼铁路工程建设提出了合理的热害防治措施。结果表明:卡乌地下热水的水化学类型为Cl-Na型,曲参岗地下热水为Cl·HCO_3-Na型,锡钦地下热水为HCO_3-Na·Ca型;研究区地下热水水化学组分的形成普遍受到硅酸盐矿物溶解的影响,其中卡乌、曲参岗地下热水的水化学组成主要受蒸发/沉淀作用的影响,锡钦地下热水的优势离子受蒸发/沉淀作用和水-岩相互作用共同的影响;卡乌地下热水为40年以前的"古水"占优势的水,锡钦地下热水为新近入渗水和古水的混合水;萨迦县卡乌地热水具有腐蚀性,且卡乌泉口出露温度达到当地沸点,为高温地热资源,隧道工程必须绕避卡乌温泉区。 相似文献
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针对我国越来越多的金属矿山进入深部开采且遭遇地下热害和通风困难双重影响,提出了利用温差能驱动深井通风的新方法,采用水力通风换热机将地下热水的势能和热能转换为风流的动能和内能。在利用对流换热将水的热能转移到风流的过程中,推导了换热机风量大小计算公式,并用MATLAB软件对换热机风流升温效果进行数值模拟研究。结果表明:风流温度与换热高度呈现线性正相关关系,其升温效果与地下热水水头、换热机进风温度、地下热水温度3种因素呈现正相关关系,且影响因素排序为地下热水水头>换热机进风温度>地下热水温度;换热机在热水水头为260m、地热水温度为55℃、空气初始温度为24℃的外在条件下,风量达54 m3/s,出风温度约为34℃。 相似文献
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Paul Ney 《Die Naturwissenschaften》1981,68(12):597-605
Types of asbestos are distinguished not only by structure, chemical compositon, shape of aggregates, and length and quality of fibers, but also by its formation. Though consisting of quite common elements, deposits are formed only under very special conditions. Its unique combination of properties has created over 3000 fields of application (about 70% in asbestos cement). Great efforts have been made to substitute all types of asbestos by harmless, similarly cheap and versatile synthetic fibers, owing to the unquestioned carcinogenic properties of all asbestos dusts. However, development of such fibers has not made any remarkable progress until recently. Consequently risk to workers in mining and manufactoring, consumers, outsiders, and the environment should be kept as low as possible by intensifying precautions and diminishing emissions. 相似文献
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This work was conducted to evaluate whether Ca-bearing additives used during coal combustion can also help with the retention of some other elements. This work was focused on the evaluation of bottom ashes collected during four full-scale combustion tests at an operating thermal fluidized-bed power station. Bottom ashes were preferred to fly ashes for the study to avoid interference from condensation processes usually occurring in the post-combustion zone. This work focused on the behaviors of S, Cl, Br, As, Mn, V, Cr, Ni, Cu,Zn, W, and Pb. Strong positive correlations with CaO content in bottom ashes were observed(for all four combustion tests) for S, As, Cl and Br(R = 0.917-0.999). Strong inverse proportionality was calculated between the contents of Pb, Zn, Ni, Cr and Mn and CaO, so these elements showed association to materials other than Ca-bearing compounds(e.g., to aluminosilicates, organic matter, etc.). Somewhat unclear behaviors were observed for W, Cu, and V. Their correlation coefficients were evaluated as statistically "not significant", i.e., these elements were not thought to be significantly associated with CaO. It was also discovered that major enrichment of CaO in the finest bottom ash fractions could be advantageously used for simple separation of elements strongly associated with these fractions, mainly S and As, but also Cl or Br. Removal of5% of the finest ash particles brings about a decrease in As concentration down to 77%-80% of its original bulk ash content, which can be conveniently used e.g., when high As content complicates further ash utilization. 相似文献
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Kurunthachalam Kannan Simonetta Corsoline Takashi Imagaws Silvano Focardi John P.Giesy 《Ambio-人类环境杂志》2002,31(3):207-211
我们曾对从意大利收集的金枪鱼、箭鱼、普通鸬鹚以及家燕体内的p,p'-DDE、多氯联苯同类物(PCBs)、多氯二苯-p-二恶英(PCDDs)、多氯二苯并呋喃(PCDFs)以及多氯萘(PCNs)浓度进行过测量. 相似文献
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G. Vollmer 《Die Naturwissenschaften》1991,78(12):533-542
In order to say something substantial about the fundamental limits of machines (especially of computers) and of human calculations, we must explicate the concept of algorithm. Such an explication is provided by the Turing machine. Thus, problems have been discovered which cannot be solved algorithmically. For other problems there are problem-solving procedures, but no elegant algorithms. That men are fundamentally superior to machines has not been shown as yet. 相似文献
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Vine Edward L. Sathaye Jayant A. 《Mitigation and Adaptation Strategies for Global Change》2000,5(2):189-216
In this paper, we present an overview of guidelinesdeveloped for the monitoring, evaluation, reporting,verification, and certification (MERVC) ofenergy-efficiency projects for climate changemitigation. The monitoring and evaluation ofenergy-efficiency projects is needed to determine moreaccurately their impact on greenhouse gas (GHG)emissions and other attributes, and to ensure that theglobal climate is protected and that countryobligations are met. Reporting, verification andcertification will be needed for addressing therequirements of the Kyoto Protocol. While the cost ofmonitoring and evaluation of energy-efficiencyprojects is expected to be about 5–10% of a project'sbudget, the actual cost of monitoring and evaluationwill vary depending on many factors, including thelevel of precision required for measuring energy andGHG reductions, type of project, and amount of fundingavailable. 相似文献
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《Journal of Cleaner Production》2006,14(17):1557-1558
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