Einstein床沙质输移理论的再研究——关于细颗粒床沙质输沙率的计算

本文对Einstein输沙模式进行了简化处理.在此基础上,通过严格的数学推导,求出了Einstein床沙质挟沙能力公式中的J₁、J₂及p积分,从而给出了Einstein床沙质输沙函数的解析关系.通过与数值解的比较,表明本文的结论是正确的.由于本文所给的解析结果较简单,所以使Einstein输沙公式有可能在实际中,特别是在河床变形计算中得到广泛应用.但是本文是在悬浮指数z<1的情况讨论的,因此结论只适用于以悬移质运动为主的细沙河流.     

地下水采样技术及《地下水采样技术规程》的编制

地下水取样是地下水调查、监测中的一项关键技术工作,必须要根据调查场地的条件和调查的目的选择合适的采样方法,并严格按照操作规程进行采样,以取得真实、有代表性的样品。本文在梳理常用地下水采样方法和采样器具的基础上,介绍了行业标准《地下水采样技术规程》的编制过程及其主要内容。该规程内容涉及地下水现场测试样品、无机检测样品、有机检测样品、气体检测样品、同位素检测样品、专项样品（包括地热水样品和饮用矿泉水样品）等的采集要求、采样方法、样品保存、质量控制等。     

Sediment Load of Asian Rivers flowing into the Oceans and their Regional Variation

Study of the major Asian rivers discharge to the ocean reveals variations of their water discharges and sediment loads.and local characteristics of river sediment concentrations.On the basis of this,the Asian rivers fall into three regions,including Eurasia Arctic,East Asia,Southeast and South Asia Regions.The Eurasia Arctic Region is characterized by the lowest sediment concentration and load,while the East Asia Region is of the highest sediment concentration and higher sediment load,and the South-East and South Asia Region yields Higher Sediment concentration and highest sediment load. The sediment loads of these regions are mainly controlled by climate,geomorphology and tectonic activity.The Eurasia Arctc rivers with large basin areas and water discharge,drain low relief which consists of tundra sediment,thus causing the lowest sediment load.The East Asia rivers with small basin areas and lowest water discharges,drain extensive loess plateau,and transport most erodible loess material,which results in highest sediment concentration.The SE and South Asia rivers originating from the Tibet Plateau have large basin areas and the largest water discharges because of the Summer Monsoon and high rainfall influence,causing the highest sediment load.In Asia,tectonic motion of the Tibet Plateau Plays an important role.Those large rivers originating from the Tibet Plateau trasport about 50% of the world river sediment load to ocean annually,forming large estuaries and deltas,and consequently exerting a great influence on sedimentation in the coastal zone and shelves.     

前进波作用下沙纹床面的净输沙方向与净输沙强度

在沙纹床面输沙过程中，假设水流从涡中取出并搬运的悬移质数量与推移质运动的沙星成比例，由12组细沙实验结果得到了沙纹床面净输沙的方向和输沙强度公式，并与他人的实验结果进行对比。     

柔性沉水植物生长对含沙水流紊动特性的影响

采用装饰塑料树在实验水槽中模拟柔性沉水植物,在一定水力条件下,探讨了柔性沉水植物生长对含沙水流紊动特性和悬移质含量分布规律的影响。实验结果表明,柔性沉水植物带中含沙水流垂向流速分布不符合无植物时的半对数分布形式。柔性沉水植物带中含沙水流纵向、横向和垂向的紊动强度和雷诺应力呈各向异性,且其最大值和最大值的位置随柔性沉水植物高度的增加而增大。植物带中垂向悬移质含量随着柔性沉水植物高度的增加而降低,沿柔性沉水植物带水流方向悬移质含量逐渐降低。     

便携式气溶胶采样器（ＭｉｎｉＶｏｌ）日常维护技巧

1仪器维护要点 1．1根据天气状况,及时擦拭切割头组件 采样器属于室外工作仪器,累积的气溶胶粒子及沙尘、降水等天气都会对仪器性能及采样的精准度产生影响。不及时清除,累积的气溶胶粒子和沙尘天气会导致采样结果失真;持续较长的降水会使采样器内湿度增大,易导致滤膜受潮、颗粒物变性。     

漏斗式全沙排沙技术及其应用

主要介绍了一种新型泥沙处理技术,即“漏斗式全沙排沙术”.该项技术既可以排除粗颗粒的推移质泥沙,也可以排除细颗粒的悬移质泥沙.对0.5mm以上的粗颗粒泥沙的截沙率为100%,对0.5mm以下细颗粒泥沙的截沙率为90%,排沙耗水量仅占渠道引水量的2%～5%.