水流

Disturbances with various patterns were exerted to the open channel flow in a flume to quantitatively investigate the variation of turbulence structure during sand ripple formation and its influence on sand movement and river bed evolution. The variation process of flow velocity is measured by means of ADV with sampling frequency of 50Hz.

本文通过在水槽实验中采集的流速过程数据，定量地研究了沙纹阶段明渠水流在不同形式扰动作用下的湍流结构，以及湍流结构对泥沙运动和床面演化的影响。

The result shows that the disturbances enhance the movement of sand, so that the incipient velocity of local sand will lower than that on the flat river bed and lead to instability of river bed and sand ripple consequently.

实验发现，扰动附近水流紊动大大增强，扰动促使局部泥沙在断面平均流速低于平床起动流速的情况下起动，并促使床面失稳形成沙纹。

It was formed when waters from an ancient ocean receded and a mammoth sandbar blocked most of the water flow to the sea. Left behind was a 1,800-square-kilometer swamp.

它的形成是由于古时候海洋退潮时大部分水流被巨大的沙洲阻截了，从而留下了1800平方公里的沼泽。

This paper introduces the application of sediment funnel to water supply engineering,especially analyzes the interception efficiency and water consumption when high sandiness stream is treaded with sediment funnel.

介绍了排沙漏斗在自来水供水工程中的试验研究，特别介绍和分析了排沙漏斗在处理高含沙水流时的截沙率和耗水率，对粒径大于0。

The influence of stress on seepage is analyzed,and the seepagestress coupling model is put forward.

岩质边坡中的水压力和水流分布是影响边坡变形和稳定的重要因素之一。

When the bed morphology is in an unstable statement, the variation of bed resistance makes the flow unstable and forms seiche.

当床面形态处于不稳定状态时，河床阻力的变化使水流处于不稳定状态，形成假潮。

The drainage system is self-formed by flow on certain geology, terrain and climate conditions, with obvious characteristic of self organization.

河流水系的形成是在一定地质、地形、气候等条件下，水流自由发展的结果，具有自组织临界性。

The shear stress of particles is about 5% of the turbulent shear stress of the water.

颗粒剪切应力的数值约为水流紊动剪切应力的5％。

In this model, not only natural convection that is caused by different vertical density, and the baffle effect of shearing stress caused by viscosity is considered, but also the effect of concentration distinction itself to leaky flow is considered

该模型不仅考虑了由于密度差引起的自然对流作用，粘滞性产生的切应力对水流运动的阻滞作用，还考虑了溶质浓度的差异对越流的影响。

Loess hilly region ; sheet flow ; soil erosion ; hydraulic parameter ; dynamic mechanism

黄土丘陵区；薄层水流；土壤侵蚀；水力参数；动力机制

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。