保山盆地永铸街气田沉积物源分析

根据研究区的基本资料和相应成果,在分析保山盆地基本构造格局的基础上,发现因保山盆地主控断层的西边在盆地演化过程中一直处于隆升状态,从而造成不同地带砾岩的分布和含量存在差异,在钻测井、地震资料中的体现也不相同.通过多种方法对永铸街气田的主物源方向进行论证后,认为永铸街气田的物源来自西边.     

Flow resistance in a compound gravel-bed bend

In this paper, the effect of a gravel-bed in a compound bend (similar to sinusoidal top view) of a natural river (Zayandehrud River flowing through Isfahan, Iran) has been investigated for flow resistance analysis, measuring the velocity with a micro current meter. The data were analysed and the following observations were made. In a compound bend, the law of the wall can be valid for up to 66% of the flow depth from the bed. The parabolic law is the most effective method for the determination of shear velocity. Based on the existing criteria for verifying the equilibrium boundary layer, the flow cannot be in equilibrium. The shear stress distribution and the sediment transport parameters have considerable influence on resistance to flow. Froude number and the flow depth relative to the representative gravel size have little effect on the flow resistance estimation.     

第四纪松散沉积层深基坑降水三维非稳定流数值模拟

目的探讨长江三角洲巨厚第四纪松散沉积层深基坑非完整井降水模拟算的理论．方法采用三维有限元数值模拟理论，以上海环球金融中心深基坑降水为例，模拟了在多层含水层复合存在、含水层最深底板埋深达149m、基坑周围挡水连续墙埋深达34m、抽水井埋深达55m．抽水井过滤器埋深为34～55m．基坑内地下水位降至埋深达26．6m的情况下的地下水复杂流动状态．结果得出的8口抽水井优化降水方案经后续工程验证正确、可靠．结论三维有限元数值模拟理论用于模拟预测此类地区的深基坑降水具有较高的可信度，采用“置大数”法处理第一类边界条件和改进单元传导矩阵调整法处理自由面边界条件能提高模型的计算速度和稳定性．     

Hydrogeochemical Characteristics of Fluorine in Shallow Groundwater of Tongshan Area

Tongshan area, a part of the floodplain of the abandoned Huanghe River, is one of the popular endemic fluorosis areas in East China. One of the reasons is high concentration of fluorine in shallow groundwater. Test results of 36 groundwater samples show that fluorine concentration in shallow groundwater is 0.18-6.7mg/L and 50% of the samples exceed the Chinese drinking water quality standard. There exists a significant negative correlation in content between Ca^2 and F^-. The correlations between fluorine concentration and other cations (for example Na^ , K^ , Mg^2 ) are not significant. The content of dissolved fluorine from the flooding sediments of the Huanghe River that varying from 5.6mg/kg to 15.2mg/kg plays an important role in forming the high fluorine groundwater. Usually, the dissolved fluorine content in silt is much higher than that in silty clay and clay. According to the geological investigation fluorine content in deep groundwater (over 60m) is less than 1.0mg/L and suitable for drinking, so it is an effective measure to prevent endemic fluorosis by extracting deep groundwater in disease areas.     

Simulation of Artificial Grain Feeding in Order to Reach Dynamical Bed Stabilisation Along the River Rhine

The Wesel-Xanten stretch of the fiver Rhine between km-812.5 and km-821.5 is one of the reaches where strong erosion leads to high maintenance efforts conceming navigability.In order to improve the naviga- tion conditions without aggravating the flood protection,but also ensuring that the ecological system of the river is not damaged,investigations of the morphodynamical processes in connection with artificial grain feeding ac- tivities have to be carried out by Federal Waterways Engineering and Research Institute.The performance of artificial grain feeding along a stretch of the lower Rhine near Wesel to prevent bed erosion by balancing sedi- ment transport was simulated in a scientific way by sensitivity studies in a 2D depth-average numerical model with graded sediment transport approach.The target of the investigations is to study the interaction of bed load supply and hydro-/morphodynamical features,and then especially to analyse and control the grain feeding measures in this section of the Rhine river.First the administrative background and target of artificial grain feeding along the waterways and then the special features regarding flow and transport characteristics of the stretch are described.After introducing shortly the mathematical basis for modelling graded sediment transport and some special treatments for the case of artificial grain feeding activities,some validation results for graded sediment are discussed.A series of numerical simulations with the objective of testing the model sensitivity to different model parameters has been carried out.Further,results of numerical simulations for the case of grain feeding are presented.     

An Investigation of Stochastic Nature of Bed Load Motion in Chuanjiang River

Bed Load Motion and its transport rate is one of the basic issues in river dynamics.In this paper, the authors discussed the stochastic nature of bed load motion in Chuanjiang River in details.Chungjiang lies in the upstream reach of Yangtze River.Its stochastic nature is shown in the following four aspects.Firstly, even though all the conditions are the same,due to the fluctuation of the flow,the bed load discharge and the location and width of sediment transport belts are different.Secondly,during the process of bed load motion, pebbles show the strong nature of intermittence.Thirdly,the sediment discharges through upstream and down- stream reach are not equal,i.e.the pebble motion exists the discontinuity.Fourthly,annual mean transport rates of bed load for different stations are different and variation of transport rate of pebbles for a given station with year is large.The four aspects will be discussed one by one detailedly.     

排沙漏斗优化及输沙特性试验研究

采用大比尺模型试验对排沙漏斗体型进行了优化研究，通过设置适当的悬板和调流墩以及漏斗的体型、尺寸，形成稳定的三维螺旋流使水沙分离实现连续排沙。排沙下界粒径较大时，可以选择较小的漏斗尺寸．使涡流强度提高以较小的耗水率排放泥沙。排沙下界粒径很小时，须选择较大的漏斗尺寸，使涡流强度适当以避免细颗粒泥沙因紊动上浮而被带入引水渠，同时还要避免泥沙在漏斗内淤积。直径60m的漏斗经优化体后，试验结果表明，工作流量为40-50m^3／s，粒径大于0．1mm的泥沙排除率达到90％，而排沙耗水率小于10％，效果良好。     

从三门峡水库的运行看潼关高程的变化

本文根据三门峡水库长期的运行资料，对三门峡水库淤积和潼关高程的变化进行了分析研究。潼关高程和入库水沙减少有重要的关系，但是水库运行也很大程度影响潼关高程。资料显示，三门峡水库潼关以下的淤积量和连续三年平均坝前水位有正比关系，而潼关高程和上述淤积又有正比相关关系。所以，降低水库的运用水位是降低潼关高程的必要条件。切实降低水库运行水位，潼关高程降低到326m附近是可能的。即使在目前水沙减少的条件下，结合降低水位运行的溯源冲刷和中小洪水的沿程冲刷，降低潼关高程仍然是可能的。     

钨锡细泥回收工艺的改进及生产实践

简要分析了大江选厂和大龙山选厂的矿石性质和原细泥回收工艺，提出了细泥回收工艺的改进意见。近两年的生产实践证明，细泥回收工艺改进是成功的，大江选厂的钨锡细泥实收率分别提高了25．42％、26．67％，大龙山选厂的钨钼细泥实收率分别提高了16．43％、2．21％，年新增效益96．455万元，经济效益显著。     

论明槽挟沙水流的阻力

从挟沙水流的能量平衡原理出发 ,指出泥沙的运动从两个方面影响水流的阻力 :一是由于卡门常数的减小而引起的阻力减少 ,二是由于推移质泥沙的存在而引起的阻力增大。两者对阻力的作用正好相反 ,因而挟沙水流阻力比清水可能减小、增大及不变 ,取决于两者的对比程度。并从理论上给出了动平整床面挟沙水流阻力的计算公式 ,该公式的计算结果与实测资料吻合较好