Composition and applied sedimentology of salt from brines of the Mamfe Basin, Cameroon     

E. Eseme  P.A. Abanda  C.M. Agyingi  J. Foba-Tendo  R.E. Hannigan 《Journal of Geochemical Exploration》2006,91(1-3):41-55

Salts produced using brines of the Mamfe Basin were analysed by XRD for their mineral composition and ICP-MS for minor element composition. Halite (NaCl) and dolomite (CaMg (CO₃)₂) constitute the major minerals with minor impurities from Mo and Cd in the chlorides and Sc and Cu in the carbonates. The mineral composition is evidence of dissolution of evaporites with parent brine of marine origin. Other elements analysed are suggested to be adsorbed to these salts and result from water–rock interaction. The elements partitioned based on their correlation to other elements are suggested to derive from sulphates including barite for Ba, sulphides for Pb, Zn, silicates for Zr, Mn and oxides for V, Cr. The electrical conductance of the brines is related to the salt yield by the equation; M = 9 × 10^− 4E− 3.27, and it can be used to estimate salt yield throughout the year. Over 1200 tons of salt consisting dominantly of grade I halite are lost annually as brines across the basin. Purification is required for some minor elements including Ba, Pb, Hg and Cd for use as a condiment. A genetic relation between the parent brine, sulphide minerals and organic matter-rich sediments is proposed.  相似文献   

Mathematical model for hydraulically aided electrokinetic remediation of aquifer and removal of nonanionic copper     

Sadataka Shiba  Yushi Hirata  Tadachika Seno   《Engineering Geology》2005,77(3-4):305-315

One of the most cost-effective in situ technologies for soil and groundwater (i.e., aquifer) remediation is electrokinetic remediation. In electrokinetic remediation, electromigration due to electric field is combined with hydromigration due to hydraulic flow by purge water to remove pollutants from aquifers through the pore water. This study aims at investigating theoretically the role of electromigration (as active movement) of pollutants and the role of hydromigration (as passive movement) of pollutants in electrokinetic remediation, and making it clear that the control variables for electrokinetic remediation are the applied voltage and the hydraulic flow rate. These aims are pursued by construction of a mathematical model based on physico-chemical considerations and by model simulations of the electrokinetic remediation applied to the virtual aquifer polluted by heavy metals of copper sulfate. According to numerical simulations with the model: (1) heavy metal (nonanionic copper) is removed from the upstream anode region and accumulated in the downstream cathode region; (2) to carry away the heavy metal outside the aquifer (global removal), hydromigration by purge water flow is essential; and (3) electromigration contributes mainly to the redistribution of heavy metals within the aquifer (local removal and local accumulation).  相似文献   

福建省晋江市城市热岛强度时空变化特征分析     

王可心  陈粲  包云轩  吕青  奴开 《热带气象学报》2019,35(6):852-864

利用传统的气象站法, 结合空间统计学方法(普通克里金插值法), 对福建省晋江市2010—2014年40个自动气象站逐小时温度资料加以计算处理, 分析了晋江市年、季、昼夜热岛强度时空变化规律。(1)晋江市年、季、昼夜热岛强度都呈带状分布, 等值线呈西南-东北走向, 年、季、昼夜变化趋势显著, 北部热岛强度高于南部。五年间热岛强度持续增强, 但增幅不大, 增速放缓。(2)城市化水平的提高, 会导致热岛强度高值出现季节提前, 故旅游区秋冬季热岛强度高于春夏季, 中心城区和产业经济区夏秋季热岛强度高于冬春季。(3)晋江市热岛效应昼夜空间分布格局差异性大, 夜间热岛强度显著高于白天, 最低值出现在14—16时, 中心城区和产业经济区最低值出现时间较旅游区略推迟, 三个功能区的最高值均出现在凌晨。   相似文献   

层析成像新算法及其在工程检测上的应用   总被引：29，自引：3，他引：29       下载免费PDF全文

杨文采  杜剑渊 《地球物理学报》1994,37(2):239-244

基于走时和振幅的层析成像反演涉及大型稀疏矩阵方程的求解，当矩阵严重病态时，目前流行的正交分解型迭代算法难以取得良好的成像效果．本文介绍一种改进的ＬＳ_ｑＲ算法，即带阻尼的ＬＳ_ｑＲ迭代算法，它应用在北京机场高速公路桥墩施工质量检测中，取得了良好的效果．  相似文献   

走向21世纪的实用地震学   总被引：6，自引：0，他引：6       下载免费PDF全文

马在田 《地球物理学报》1995,38(4):539-547

实用地震学包括地震勘探、深部地震测深、工程地基与质量勘查以及浅部地质灾害预测等，在国民经济各方面起着重要作用，特别是在我国油气资源勘探与开发中起着并将继续起着不可替代的作用．在即将迈向２１世纪的今天，我们探讨一下实用地震学未来发展的道路是很必要的．实用地震学在２１世纪仍将在地学研究和国家建设中发挥它应有的作用，而且对它的要求也将越来越高，因而它在理论和应用方面都有诸多疑难问题要研究．本文就其发展现状、未来的理论研究和新技术的应用问题做些探讨．  相似文献   

Parameterisation of the Planetary Boundary Layer for Diagnostic Wind Models     

Massimiliano Burlando  Emilia Georgieva  Corrado F. Ratto 《Boundary-Layer Meteorology》2007,125(2):389-397

The planetary boundary-layer (PBL) parameterization is a key issue for the definition of initial wind flow fields in diagnostic models. However, PBL theories usually treat separately stable, neutral, and convective stability conditions, so that their implementation in diagnostic wind models is not straightforward. In the present paper, an attempt is made to adopt a comprehensive PBL parameterisation, covering stable/neutral and unstable atmospheric conditions, which appears suitable to diagnostic models. This parameterisation is implemented into our diagnostic mass-consistent code. A validation of the consistency between the implemented PBL parameterisations has been checked through an analysis of the sensitivity of the vertical wind profiles to atmospheric stability.  相似文献   

若尔盖等地风能资源评价     

胡毅  青泉  董明琨  何伟贤 《成都信息工程学院学报》1990,(4)

本文用平均风速和最大风速法对若尔盖等三地的韦伯分布参数k、c进行估算,并用韦伯分布计算风能的指标。计算表明:若尔盖、红原属风能可利用区,用风力发电是有利用价值的;阿坝属风能贫乏地区。  相似文献   

Everyday work: A survey of the 2014 Applied Geography Conference     

《Applied geography (Sevenoaks, England)》2015

A selection of application papers presented at the 2014 Applied Geography Conference in Atlanta, Georgia are included in this special issue of Applied Geography. The wide-ranging topics of the papers reflect the many directions Geography is applied to solve practical issues in our society.  相似文献   

Littering in context(s): Using a quasi-natural experiment to explore geographic influences on antisocial behavior     

《Applied geography (Sevenoaks, England)》2015

Social science literature suggests that neighborhood-based visual cues have substantive effects on individuals' littering behaviors. Experimental research on this topic typically alters the appearance of a selected public location, and then monitors changes in littering due to these tightly controlled esthetic changes. The general finding is that littering occurs more frequently in relatively disorderly settings. The current paper extends this work by testing whether or not the same finding holds in more “real life” situations, wherein the operative visual cues come directly from the environment rather than through experimental manipulation. Specifically, the paper empirically identifies two study sites that serve similar functions in their urban system, but that differ markedly in contextual features. At the first site (#1), visual cues include liquor stores, vacant structures, and a noisy interstate highway. Notable visual cues at site #2 are scenic vistas, well-maintained housing, and greenspaces. When the same quasi-natural littering experiment was conducted at both locations, the littering rate was significantly higher at site #1 compared to site #2 (after controlling for individual-level demographic attributes). This result adds value to the applied geography community, as it confirms that spatially-based attributes do influence individual behaviors in a manner consistent with controlled, comparatively acontextual experimental findings. Additionally, the results implicate policy strategies that might be useful for counteracting antisocial urban behavior.  相似文献   

资源环境系列制图研究的现实基础与发展     

苏时雨  苏映平 《云南地理环境研究》1991,3(2):9-16

本文侧重于全国性资源环境及有关自然条件等专题制图工作的现实基础和成就,作简要总结和回顾。针对提高和重新认识制图效益和重点进行讨论,提出科学效益是基础,社会效益是目的,经济效益是根本,为资源环境的合理开发利用提供依据,并提出今后发展设想。  相似文献