On the topography influence on subsidence due to horizontal underground mining using the influence function method

The classical influence function method is widely used in mining subsidence prediction, but its use is typically limited to predicting the subsidence associated with horizontal stratiform underground mining when the ground surface is flat. By investigating the topography influence on subsidence under simplified mining conditions, this study attempts to improve the original influence function method to take topographic variations into account. New asymmetrical influence functions are used to simulate element subsidence. Integrating this asymmetrical approach into the influence function method increases the realism of subsidence computation when compared to the numerical simulation results. The maximum subsidence value and influence angle got from field data are introduced into the improved method, then two field subsidence cases are studied and acceptable comparison results are achieved. This improved method should serve as the foundation for future work.     

近40年来气候变化对青海盐湖及其矿产资源开发的影响——以小柴旦湖为例

青海是中国盐湖主要分布区之一,蕴藏着丰富的矿产资源。文章以RS和GIS技术为基础,从20世纪70年代、90年代、2000年前后、2008~2009年和2013~2014年五期Landsat遥感影像中提取了青海面积大于10 km2的所有盐湖(不包括干盐湖),分析了其近40年来的变化趋势:总体上,盐湖总面积除在2000年前后有所减少外,基本上呈现增加的趋势;具体而言,2000年前后,萎缩的盐湖主要分布在柴达木盆地;其他时期均呈现全面扩张的趋势。在全球气候变暖的大背景下,通过分析青海地区11个气象台站的年平均气温、年降雨量和蒸发量数据,可知青海地区气候呈现了向暖湿方向转型的趋势,且2002年之后更为明显。最后,以青海省小柴旦湖为例,分析了湖泊淡化、矿产资源贫化对盐湖资源开发的影响,具体为:1资源开发成本升高、难度加大,甚至使一些处于工业开发临界品位的盐湖失去开发价值;2盐湖淡化条件下,锂等矿产资源有效提取技术亟待研发;3政府制定矿产资源开发政策时,需要对气候及盐湖的动态变化过程综合考虑。以上说明,青海地区的暖湿气候使盐湖大幅度淡化,给盐湖矿产资源开发带来了新的挑战。     

熵值理论和改进BP网络在湖泊富营养化评价中的应用研究

针对湖泊型饮用水源地水体污染、富营养化加剧的问题,引入熵值理论,建立单指标营养状态指数(TSI)和熵权藕合的湖泊综合营养状态指数模型(STSI),计算得到湖泊综合富营养状态指数判断湖泊富营养综合状态;基于神经网络仿真理论和Matlab软件系统,采用附加动量法和自适应学习速率改进BP算法,建立5-3-1结构型式的BP网络模型对湖泊富营养状态进行仿真预测。综合富营养化指数模型及改进BP模型应用于评价及预测固城湖富营养状态,并对模型评价结果进行验证。结果表明,改进BP网络模型可以有效地综合判断水体状态,为富营养评价及预测提供新的方法。     

Compare on characteristic of different chemical type salt lake brines from Tibet during evaporating

正1 Introduction China is a country which has many salt lakes.Tibet is the area where have numerous salt lake,because the sources of water have multiple chemical type,resulting in Tibet salt     

Research of Recycled Salt and Glauber’ Salt Precipitation Rules of Yabulai Salt Lake Brine

正1 Introduction The main production of Yabulai salt lake was original salt and recycled salt many years ago.After decade’s production,the sale lake resource is more and more deficient.Glauber's salt and magnesium salt are concentrated in brine now.It could affect the quality of the salt.In recent years,research had done much work to     

Isotopic Composition of Dissolved Carbonates Meromictic Soda Lake Doroninskoe(Eastern Transbaikalia,Russia)

正1 Introduction Meromictic soda Lake Doroninskoe localized in the intermountain area,filled with continental sediments of the Mesozoic,in the upper basin of the river Amur.Coordinates of its location are N51°14'42"E112°14'40",     

Comprehensive Development and Utilization of Saline Lake Groups in Dingbian,Shanxi Province of China

正The Dingbian Saline Lake groups are in Dingbian County,northwest of Shaanxi province,and located on the border area of the Loess Plateau and Maowusu Desert in Northern Shanxi.It's altitude is more than 1300m.The     

Long-term Changes in the Saline Lake Qarun(Egypt)

正1 Introduction There is now ample evidence of the impacts of the recent climate change and anthropogenic activities on different saline lake ecosystems.All over the world salt lakes are threatened by climate change,water diversions upstream for agricultural purposes,watershed changes,introduction of aliens,etc.that result in catastrophic     

干涸尾闾湖盆区泥漠地表磨蚀释尘特征

沙粒的表面磨蚀效应是地表产尘、释尘的重要机制,针对干湖盆泥漠地表开展磨蚀释尘实验研究,对理解干湖盆地表风蚀过程及盐碱尘暴形成机理具有重要意义。对采自西居延海干涸湖盆泥漠地表土样进行室内磨蚀模拟实验,研究了不同粒级（细、中、粗）沙粒不同落沙角度（30°,45°,60°）的磨蚀效应。结果表明：（1）泥漠地表磨蚀实验中能够产生明显释尘效应的沙粒粒级阈值为中沙（0.25 mm<M_d<0.50 mm）;（2）磨蚀粒径粒级相同时,磨蚀角度会对泥漠地表磨蚀释尘速率产生影响,磨蚀量的角度排序为60°>30°>45°,但同一粒级3种角度下的磨蚀释尘率差异不显著。（3）磨蚀角度为45°时,计算了泥漠地表的质量磨蚀率与能量磨蚀率,其中中沙为0.04 g·kg^-1、0.43 g·J^-1,粗沙为0.08 g·kg^-1、0.74 g·J^-1,极粗沙为0.26 g·kg^-1、2.54 g·J^-1;在磨蚀沙粒粒级倍增而磨蚀角度不变情况下,泥漠地表磨蚀释尘率与能量磨蚀率未发生正比例线性增长变化。     

对我国政府在全球采掘业透明倡议中应持立场的思考和建议

历经10余年的发展,采掘业透明倡议已经发生了巨大变化,西方发达国家开始积极介入,主动宣布试点或计划实施。形势的变化要求我国及时调整以往所持立场。本文简要介绍了全球采掘业透明倡议的组织架构及运作、实施现状,深入分析了各利益相关方的动机,对其未来发展加以研判,并结合我国涉及采掘业透明倡议的情况,提出了新形势下我国短期内不宜实施,但须及时调整立场;鼓励金融机构和企业介入EITI和其他反腐败倡议;政府应考虑成为EITI的正式支持国。