Response of downstream sediment to water resource development in mainstream of the Lancang River

The impact of hydropower cascades of the Lancang River on downstream sedimentation has become one of the key problems in the research of the transboundary water resource development and its possible environmental effects. In this paper, the newest sediment data series spanning 17 years （1987-2003） at Yunjinghong hydrometric station and Chiang Saen hydrometric station, in northern Thailand, are analyzed to reveal these effects. Monthly mean sediment concentration data of the two stations are compared in-phase and yearly series are analyzed by the method of correlation and regression analysis and causality test. The analysis result shows that, though both of them are located at lower reaches of Manwan and Dachaoshan hydropower stations which are already constructed and in use, the sediment responses of the two stations are different under the regulation of the hydropower stations Annual series at Yunjinghong station are positively correlated but do not match well with those at Chiang Saen station. In addition, the results of Granger causality test on the time series also suggest that the series of maximum monthly mean sediment concentration of the Yunjinghong station each year may give cause for the ones of Chiang Saen station, while the series of minimum monthly mean sediment concentration each year and annual mean sediment concentration of Yunjinghong do not evidently give cause for the ones of the other station. Undoubtedly, this discovery will provide new evidences to assess the impacts of cascades construction in mainstream of the Lancang River on the variation of downstream sediment and its transboundary effects.     

厦门海域氮、磷的主要来源分析及其控制措施

基于近年来的监测结果，本文从厦门海域氮、磷含量水平的年际变化趋势入手，结合无机氮、活性磷的平面分布特征，对厦门海域氮、磷的主要来源进行较详细的分析．结果表明，从19％年至2003年厦门海域中无机氮和活性磷含量水平均呈上升趋势，并且农村（农业）非点源的输入是其主要来源之一．在此基础上，着重就农村（农业）非点源污染控制的技术措施和相应的管理对策进行论述．     

太原市集中供热双热源联网运行方案的分析

从优化供热系统工况，提高供热的经济性出发，利用HACNET软件对太原市集中供热双热源联网系统理想运行方案进行了可及性分析，确定了理想运行方案的运行调节方式。     

铜镉渣浸出工艺的研究

铜镉渣溶解浸出工艺条件的改变，对金属元素浸取速度和回收率有较大的影响．通过对铜镉渣粒径、浸取温度、硫酸浓度、搅拌速度等条件的研究，找到了最佳酸浸条件，在选定的工艺条件下，Zn、Cd、Cu等金属元素的总浸出率可达到98．5％．     

河流表层沉积物界面性质的研究

运用表面络合模式和原理，研究了黄河表层沉积物的界面特征，确定了零电点、电荷密度、表面吸附位和表面固有常数，用原子吸收分光光度法测定了天然水环境生物膜对铜和镉的吸附作用。     

深海泥的矿物组成及其物化性能研究

采用化学分析、X射线衍射、差热和热重分析、粒度与比表面积分析等技术、方法对5个我国南海深海泥样品进行了研究.结果表明,不同区域的深海泥中,其矿物组成有显著的差异,其中粘土矿物、石英、碳酸盐为主要的结晶相矿物;同时,非晶质粘土矿物广泛发育.深海泥中的矿物质具有粒径小、比表面积大、粘土矿物结晶程度差等特点,因此具有较好的活性.深海泥将是一种巨大的潜在非金属矿产资源.     

荆马河、废黄河底泥重金属污染的对比研究

通过对纳工业废水为主的荆马河和纳生活污水为主的废黄河底泥重金属进行地累积指数污染评价、潜在生态危害评价、污染成因和底泥重金属质量分数的相关性分析，得出荆马河重金属的污染程度和潜在生态危害程度明显重于废黄河，重金属的来源不同，但其相关性相似，针对不同成因，对两河重金属污染提出了相应的治理措施建议。     

黄骅港外航道大风骤淤的机理及其整治

黄骅港位于渤海湾西南，是建在淤泥质海岸上的人工港，在特殊大风期间，即E向或ENE向6级以上的海向风廷时14小时以上时，外航道的淤积量大大超过原先的预测值，且淤积物为密实、坚硬、难以疏浚的粉沙。本研究表明，这一问题产生的原因是堤头旋涡的输沙作用，卫星图像和数模证明了堤头旋涡的存在；同时还对设置垂直和平行于海岸线防波堤的两种整治方案作了讨论。     

Soil Erosion on a Slope without Vegetation： a Simulating Experiment on a Bare Land in Mt. Tanakami

0　IntroductionManystudieshavebeendoneonthesedimentdischargeinMt.Tanakami .Thosestudiesconcerntheamountofsedi mentsandfewdiscussionsabouttheprocessonly .Andthesedi mentyieldmechanismindevastatedslopeinMt.Tanakamiisnotfullyunderstood.Inordertorecordthewholeprocessofsoilero sionfromthebeginningofprecipitation ,totheendofsedimentmovement,asimulatingexperimentbyusingartificialrainiscon ducted .Basedonthisexperiment,andbyfurthercomparingwiththepreviousdataofsedimentsinthisarea,somebasicdataaboutc…     

试论电教课的干扰与控制

对电化教育运用过程中的干扰源和干扰的常见类型,提出了系统设计控制、目标控制、程序控制、心理控制等几种有效避免各种干扰的产生手段以及提高教师电教素质和专业电教人员的具体措施。