盐湖卤水体系的热力学模型及其应用Ⅲ：在Li^＋，Na^＋，K^＋，Mg^2＋／Cl^-，SO4^2- -H2O体系加工工艺方面的应用          下载免费PDF全文

宋彭生  姚燕 《盐湖研究》2004,12(3):1-11

在第 1报告和第 2报告中介绍了获得全部Pitzer参数的“盐湖卤水体系”Li+ ,Na+ ,K+ ,Mg2 + Cl-,SO2 -4-H2 O( 2 98 1 5K)在溶液物理化学方面和相平衡预测方面的应用后 ,在这一报告中简要报道模型在卤水加工工艺方面的应用。主要包括卤水在 2 5℃等温蒸发中析盐顺序的理论预测 ;蒸发量与析盐量、成卤量间关系的计算 ;含锂复盐加工问题等  相似文献   

新疆温宿县盐场地区水系沉积物地球化学特征及找矿效果     

李天虎  彭桥梁  王伟  高满新  熊中乙 《西北地质》2022,(1):78-92

研究区位于库车前陆坳陷盆地砂岩型铜矿带上,且与滴水铜矿位于同一成矿带上,具有较好的铜找矿前景.1 ∶ 5万水系沉积物测量成果显示,区内Cu元素背景值远低于地壳元素克拉克值,但其在苏维依组(E3s)、康村组(N1-2k)中具有较强的变异系数和较高的离差值,这说明Cu元素在以上地层中得到了富集;从元素多元统计分析来看,Cu...  相似文献   

Spatially Located Platform and Aerial Photography for Documentation of Grazing Impacts on Wheat   总被引：11，自引：0，他引：11  

Mounir Louhaichi  Michael M. Borman  Douglas E. Johnson 《国际地球制图》2013,28(1):65-70

Abstract

Goose populations that winter in Oregon's Lower Willamette Valley have increased from 25 000 to more than 250 000 birds in the last 25 years, resulting in heavy grazing of wheat and other crops. To map and document the extent and intensity of goose impacts on wheat fields, we combined rectified aerial photography with both globally positioned ground observations and vertical platform photographs. Aerial photos revealed areas of fields with sparse wheat cover while platform photos documented the cause. We estimated wheat cover in ground level photographs by ratioing red, green and blue digital numbers. From platform photographs we recorded occurrence of grazing (from grazed leaf tips), intensity of grazing (from residual plant cover and leaf length), and other indicators of goose use (footprints and droppings). Because the ground photographs were spatially positioned, we could use this information to verify the cause of “thin” wheat. Crop damage from grazing/trampling, water submergence, and other factors was evident. Our results illustrate practical ways to combine aerial and ground‐level image analysis, spectral observations, and global positioning systems to quantify field conditions in wheat.  相似文献   

Assessment of salt affected soils in India using GIS     

A. K. Mandal  R. C. Sharma  Gurbachan Singh 《国际地球制图》2013,28(6):437-456

Salt affected soils are characterized by variable distribution and dynamic nature. Based on Landsat data from 1986/1987 supported by ground truth, salt affected soil maps were prepared at 1:250,000 scale for 14 states and a union territory (UT). A map legend was evolved that described the nature, degree and extent of salt affected soils suitable for varied physiographic and agroclimatic regions of the country. Fifteen categories of salt affected soil were identified for the entire country. These were merged to two categories – saline and sodic – for management purposes. Digitized maps were developed in a geographical information system (GIS) depicting salt affected areas of the country. An area of 6.73 million ha of salt affected soils was estimated for the entire country. State-wise estimates showed that this extensive area is distributed over the Gangetic plain of Uttar Pradesh; the arid and semiarid regions of Gujarat and the peninsular plains of Maharashtra state. A significant area is also located in the coastal region covering seven states. The salt affected soils are primarily saline in deltaic (C), coastal (D) and mud flats/mangrove swamps (G) and sodic in alluvial (A), aeofluvial/aeolian/arid (B) and peninsular (F) plains. The distribution of salt affected soils in agroclimatic zones (ACZs) showed occurrence in Gujarat plain, East Coast plains, Upper-Gangetic plain, Trans-Gangetic plain, Central Plateau, Lower-Gangetic plain and Southern Plateau of the country.  相似文献   

Bridge pier failure probabilities under combined hazard effects of scour, truck and earthquake. Part II: failure probabilities     

Zach Liang  George C. Lee 《地震工程与工程振动(英文版)》2013,12(2):241-250

In many regions of the world, a bridge will experience multiple extreme hazards during its expected service life. The current American Association of State Highway and Transportation Officials (AASHTO) load and resistance factor design (LRFD) specifications are formulated based on failure probabilities, which are fully calibrated for dead load and non-extreme live loads. Design against earthquake load effect is established separately. Design against scour effect is also formulated separately by using the concept of capacity reduction (or increased scour depth). Furthermore, scour effect cannot be linked directly to an LRFD limit state equation because the latter is formulated using force-based analysis. This paper (in two parts) presents a probability-based procedure to estimate the combined hazard effects on bridges due to truck, earthquake and scour, by treating the effect of scour as an equivalent load effect so that it can be included in reliability-based failure calculations. In Part I of this series, the general principle for treating the scour depth as an equivalent load effect is presented. In Part II, the corresponding bridge failure probability, the occurrence of scour as well as simultaneously having both truck load and equivalent scour load effect are quantitatively discussed. The key formulae of the conditional partial failure probabilities and the necessary conditions are established. In order to illustrate the methodology, an example of dead, truck, earthquake and scour effects on a simple bridge pile foundation is represented.  相似文献   

屋顶雨水回灌裂隙岩溶含水层连通示踪试验   总被引：1，自引：0，他引：1  

何茂强  王维平  朱平 《地下水》2012,(2):3-5

雨水回灌后对岩溶水的影响分析和效果需要对回灌井和下游的观测井监测数据说明。由于岩溶含水层中岩溶发育极不均匀,在测定地下水位并判定出地下水流向的基础上,连通示踪试验是选择与回灌井相对应的观测井的有效办法。用氯化钠作为示踪剂,监测不同测井不同埋深地下水电导率随时间变化的方法确定了岩溶水观测井选址、岩溶含水层的结构及水文地质条件。示踪试验结果表明,3#观测井(西院井)可用来监测雨水回灌效果,并计算出该地区的地下水势流速在9 m/h～20 m/h之间。该成果对北方地区岩溶含水层回灌和环境评价具有重要的参考价值。  相似文献   

老挝东泰钾盐矿区矿床控矿因素探析     

成世才  宋永芬  马浩宁  亓协全  潘爱宏 《山东地质》2012,(4):15-18,29

通过对区域地质、构造和岩相古地理的研究,从成矿阶段的角度,将控矿因素分为背景控矿因素、沉积控矿因素、改造控矿因素。得出：背景因素为区域性盆地沉积环境形成条件;沉积控矿因素直接控制了工区石盐矿层的层理形态;改造控矿因素中,局部构造对矿层的改造是矿区盐层多呈背斜分布且轴部较两翼矿层大幅变厚的原因,钾石盐出现在光卤石矿层顶部是因为上部裂隙水或者封存的老卤水向下侵蚀光卤石矿层顶部,溶蚀了溶解度相对较大的MgCl2,而溶解度相对较小的KCl被保留下来,从而多在上盐层光卤石矿顶部形成再生或次生钾石盐矿。  相似文献   

泰安市岩盐资源开发利用与保护工作探析     

张树淇  李文孟  李庆广  郝瑞娥 《山东地质》2012,(3):61-64

随着岩盐资源开发强度逐年加大,开发利用保护任务日渐繁重,由于岩盐独特开采方法和工艺,应探索相应的监管措施和手段。通过对大汶口岩盐资源赋存特点和开发利用现状分析,指出其开发过程中存在的问题,就岩盐开采方法和工艺的监管措施和手段进行探索,提出开发利用和保护建议,从而有利于促进加强岩盐资源的开发利用和保护工作。  相似文献   

长江河口盐沼湿地酸挥发性硫化物的时空分布特征及影响因素     

王永杰  郑祥民  周立旻  翟立群  钱鹏  吴永红 《地球化学》2012,(2):158-165

以长江河口典型潮间带(崇明东滩湿地)不同地貌单元植被根际柱样沉积物(0~33 cm)为研究对象,探讨了长江河口潮间带表层沉积环境中酸挥发性硫化物(AVS)的时空间变化特征及其与环境因子的关系.结果表明,不同植被根际沉积物中 AVS 含量存在显著季节变化,表现为:互花米草大于海三棱藨草和芦苇.各采样点根际沉积物中 AVS 含量垂向变化为:高潮滩芦苇,随深度的增加而降低;中潮滩互花米草与海三棱藨草,随深度的增加先增大后减小,且在地面下约20 cm 处显著增大. Pearson 相关分析表明,沉积物中 AVS含量与<16μm 的颗粒物、有机碳含量及含水率之间不存在简单的正相关关系.根际沉积物中 AVS 含量的时空变化可能受潮汐、植被生长等因素的综合影响,其时空变化特征反映了长江河口潮滩复杂多变的氧化还原条件.与芦苇和海三棱藨草相比,入侵物种互花米草对沉积物中硫酸盐异化还原有显著影响,其可能改变了潮滩湿地生态系统原有的氧化-还原生物地球化学循环过程  相似文献   

长江口盐沼土壤有机质分布与矿化的空间差异   总被引：2，自引：0，他引：2  

陈庆强  杨艳  周菊珍  张国森  崔莹 《沉积学报》2012,30(1):128-136

在长江口崇明东滩两类植被(互花米草、土著植被)区域分别选择一条纵向剖面,在高潮滩、中潮滩及光滩取得柱状样,利用颗粒有机碳(POC)含量、碳稳定同位素组成、土壤C/N比与颗粒组成等资料,研究盐沼有机质的分布与矿化特征。结果表明,两个纵向剖面的相同高程部位柱样之间,颗粒有机碳δ13C与POC含量的深度特征均存在显著差异;两个柱样的δ13C与POC含量的平均值均相差较大。互花米草对高潮滩柱样有机质的含量与组成均产生了明显影响,对中潮滩柱样有机质组成已有一定影响;土著植被对高潮滩柱样有机质组成的影响显著。盐沼植被对土壤有机质的分布与矿化均产生了明显影响。高潮滩柱样矿化阶段不同的有机质组分混杂,中潮滩柱样有机质的组成相对简单,矿化程度较弱。柱样粘粒含量与含水量在垂向上变化频繁,盐沼原始沉积层序对柱样的物质分布特征具有本底制约。不同高程部位柱样之间,有机质的深度分布特征以及矿化程度差异显著,盐沼碳动态受到潮滩特征性动力沉积过程的显著影响。  相似文献