Non-Uniform Sediment Transport Downstream from Reservoir     

李义天  陈飞 《天津大学学报(英文版)》2008,14(4):263-270

The transport characters of non-uniform sediment before and after the reservoir operation are compared and analyzed. Field data from the Three Gorges Reservoir (TGR), Danjiangkou, and Sanmenxia reservoir indicate that the transport character of coarse particle is various in different reaches. Before the reservoir operation, the dramatic decrease of the hydraulic condition in some reaches is the main reason to cause the coarse particle deposited. After the reservoir operation, almost all grain sized sediment may be eroded, when the reach is eroded seriously. However, the transport character of the coarse particle will be consistent with what it was before, when the reach is not eroded seriously. The deposition amount will be less than its pre-dam value, and it will tend to decrease with the time going on. Erosion of fine particle results from its unsaturation. Long-distance erosion downstream from reservoir is caused by shortage of the supply from riverbed, especially the shortage of fine particle. Supported by the National Basic Research Program of China(“973” Program, No.2003CB415200). LI Yitian, born in 1957, male, Prof.  相似文献   

政治暴力与政治哲学     

李义天 《中国图书评论》2010,(11):120-122

政治哲学作为一门规范性知识,常常向人们介绍各种应然原则,勾勒各种美好的政治秩序。对读者来说,政治哲学似乎更喜欢报道“好消息”,而不愿意把笔墨花在那些被视为阴暗、消极乃至丑恶的东西上。充斥着血腥和强迫、伴随着恐惧与死亡的“政治暴力”无疑就属于后者。  相似文献   

从道德教育到品德教育     

李义天 《中国德育》2022,(1)

各位老师、各位同学,大家好!非常高兴受邀参加第十九届全国高校青年德育工作者论坛。我是第一次参加这个论坛,所以对论坛的了解更多是从主办方的介绍中知晓的。但是,对于论坛的主题——德育和德育工作,我很感兴趣。清华大学设有高校德育研究中心,是教育部人文社会科学重点研究基地。  相似文献