无电应急启闸操作器在涔天河水库的应用

对卷扬启闭机无电液控应急操作器的结构和操作原理做了详细介绍,并就其对水利、水电工程的安全性作用进行了分析,以涔天河水库扩建工程中启闭机无电应急液控操作器的成功应用为例,介绍应急操作器对水库泄洪安全的保障,为今后同类工程提供参考。     

北京山区沟域经济发展的空间结构

Valley economy is a new mode in mountainous area development that is defined by various characters of valley development, and is a distinguishing economical geographic pattern for mountainous area development. The special spatial coupling relations in the dis-tribution of different mountainous elements in valleys are new subjects for the mountain de-velopment studies, and such studies are meaningful both for researches and practices.Based on the long term researches on mountainous area development and following a brief exploration into the connotations and the spatial organizing process of valley economy, the authors analyzed the present situations of the development of valley economy in Beijing'smountainous areas, studied the characteristics and the impacts of the spatial structural changes of the valley economy in Beijing's mountainous areas, and finally proposed a rational arrangement of the spatial structure of the valley economy in Beijing's mountainous areas. It is considered in this study that valley economy plays an important role in the development and functional transformation in Beijing's mountainous areas in the new epoch. Firstly, valley economy is not outlined by the administrative boundaries, and it connects most of the villages in the mountainous areas roughly along the major transportation lines. Therefore, valley economy can exert positive influence on the development in the mountainous areas, at least in the aspects such as the rearrangement of industrial structure in the mountainous areas and the coordinated development of rural and urban areas. In addition, it is found that the valley economy in Beijing's mountainous areas is evolved in a spatial organizing stage of secondary concentration, which is characterized by resource-saving, ecological protection and industrial optimization. Therefore, the development of valley economy will be helpful to the coordination between ecological protection and economic development in the mountainous areas, and will promote the integrated development of the mountainous areas. The developing mode of the valley economy in Beijing's mountainous areas will provide the basis for the decision-making in the transformation of the functional roles of Beijing's mountainous areas, and on the other hand, will present experiences for the studies in the mountainous areas outside of Beijing.