| 1. | Choice of slit - type bucket parameters and estimation of scour hole depth
一级直线边墙窄缝挑坎参数选择与冲坑深度估计 |
| 2. | 4 . experiments about the influence of aeration on scour hole show , aeration decrease the scour depth
证明了冲刷坑的形成对下游水流流态及坑底脉动压强特性有较大的影响。 |
| 3. | The relationship between the air concentration and the scour depth can be expressed as an exponential function . aeration does not affect the shape of scour hole
掺气浓度c _对冲坑深度的影响，可表达为掺气浓度与冲坑无量纲深度的幂函数关系。 |
| 4. | Silt will deposit there . velocities around groin head are larger than the scour velocity and scour hole may develop in this area . this would affect the stability of spur dikes
受丁坝阻挡，坝田所在的边滩区域流速很小，泥沙在此淤积:而坝头附近流速较大，通常在此区域形成冲刷，影响丁坝的稳定性。 |
| 5. | Overall , the average deposit slope , changes in cross sections , scouring hole , and sediment discharge of downstream channel of dam no . 4 increased with deeper opening depth of dam no . 3
由实验结果得知，随三号坝坝体在断面拆除深度加深时，四号坝下游的淤砂坡度、断面变化、冲刷坑与输砂量变化会随之增大。 |
| 6. | According to the similar rule , a movable bed model for downstream channel and the particle size distribution of the model silt in the channel and the scour hole are designed . a theoretical method of size distribution in the scour hole is devised
根据模型律设计了太平湾尾水渠动床模型，分别确定了河床中和冲刷坑中模型沙的配比，并对冲坑中的床质级配进行了理论推导。 |
| 7. | ( 5 ) according to the calculated average section velocity . we can decide the type of the revetment . ( 6 ) when the scour hole depth of the dam head and trail parts is calculated inthe paper . we can validate whether the revetment material is strong enough to resist the degradation of the flood flow
根据以上计算所得的各断面平均流速，初步确定需要铺设的摘要护面类型计算在铺设护面以后坝首和坝末的冲坑深度，以验证护面材料是否可以抵抗洪水泄流的冲刷。 |
| 8. | The ratio of the length to the depth of scour hole decreases with the increasing scour depth , in spite of the reason is the increase of the air concentration , the decrease of the jet velocity or the decrease of the jet thickness . 5 . governing equations of the aerated jet flow are established
掺气对冲坑形态并没有实质性的影响，冲坑的宽深比随冲坑深度的减小而增大，无论造成冲坑深度减小的原因四） 1大学i学博士学位论文是掺气、降低流速还是减小入射水舌厚度，其变化规律都可用相同的直线关系表示。 |
| 9. | The main contents and conclusions are as follows : 1 . the dynamic pressure on the original riverbed and the scour hole are measured . the results show that the characteristics of dynamic pressure in the scour hole are the same as that on the original riverbed
表明在基岩冲刷过程中以及冲坑稳定后，射流冲击区的脉动压强与冲坑形成前一样，都是以低频大振幅为主，说明在冲刷坑形成后，射流冲击区水流与无冲坑时一样，都是大尺度涡不断破碎和小尺度涡不断生成的过程。 |
| 10. | With same opening depth applied at dam no . 3 , deeper scouring hole was found at the downstream channel of dam no . 4 when the dam - conversion was conducted simultaneously . besides , the depth of downstream scouring hole of dam no . 4 increased with increasing opening depth at dam no . 3 . 3 . changes in the channel cross sections between dam no . 3 and no . 4
三号坝坝体拆坝的方式会对四号坝下游冲刷坑的深度会产生影响，由坝体相同断面的拆除，结果发现一次拆除会比分次拆除时造成冲刷坑的深度较深，而冲刷坑的深度会随著下游坝体拆除的深度增加而变大。 |
