越南小中河水电站金属结构设计

介绍了越南小中河水电站的工程概况和金属结构的布置与设计。     

朔州市农村饮水解困工程建设经验、存在问题及对策

文中总结了朔州市在农村饮水解困工程建设中的经验，论述了存在的问题并提出了相应的对策及建议。     

水平荷载作用下排桩受力变形影响因素分析

结合某排桩支护基坑工程,利用有限元软件ADINA建立基坑三维模型,通过改变桩长、桩径、桩侧水泥土墙和桩侧土体参数(弹性模量、泊松比)进行了三维有限元模拟,分析了几种因素对排桩变形的影响,得出的结论对类似地质条件的基坑工程支护具有一定的借鉴意义.     

On the Inapplicability of the Cobb-Douglas Production Function for Estimating the Benefit of Water Use and the Value of Water Resources

The Cobb-Douglas production function is often used to estimate the benefit of water use and the value of water; however, this is an incorrect application. A typical example of the inapplicability is that a negative output elasticity of water resources may be reached when empirical data is collected from the United States, Japan and the city of Beijing in China, where economic growth still increases when the quantity of water use decreases. It is counter-factual that the benefit of water use or the value of water resources are negatively associated with economic production as estimated by the Cobb-Douglas production function. In the case of a positive output elasticity of water resources, the Cobb-Douglas production function cannot be used either. The main reason is that the elasticity of water resources, as an input factor, reflects only part of its total contribution to economic output. In other words, the contribution of water resources to total economic growth, to a great extent, are embodied in total factor productivity, which refers to the portion of output that cannot be explained by the amount of water resources input in the Cobb-Douglas production function. For example, many technological and socio-economic inputs such as the investment on water saving technologies and the optimization of water use structure, surely embody the value of water and account for total economic output, yet these factors are not reflected by the economic output elasticity of water resources in the Cobb-Douglas production function.     

白莲崖水库泄洪中孔体型设计研究

白莲崖水库泄洪中孔具有流量大、淹没深度小、有压洞洞身及出口位于陡坡段等特点,且其右侧泄洪中孔进口位于山坳内.该类型泄洪中孔体型设计难度较大,进口易出现吸气漏斗旋涡,洞内易出现较大负压,甚至在洞内出现明满流过渡等恶劣流态.文章介绍了设计过程中根据本工程特点,结合水工模型试验,研究确定泄洪中孔体型的情况.     

Heat transfer at ice-water interface under conditions of low flow velocities

The heat transfer at the ice-water interface is closely related to the hydrodynamic and physical properties of the water body.It affects the ice cover thickness and the water temperature underlying the ice cover.This paper studies the heat transfer from the water to the ice cover.Based on the flume data,a linear relationship between the ice-water heat transfer coefficient and the flow velocity beneath the ice cover is established and the calculated dimensionless ice-water heat transfer coefficient is 1.1×10-3.This empirical relationship can be applied to estimate the ice-water heat transfer of reservoirs,lakes and other freshwater bodies when the flow velocity under the ice cover is in the range of 0.024 m/s-0.110 m/s.     

古运河浅埋暗挖超前支护效果影响因素分析

根据浅埋暗挖区工程地质条件和固结注浆原理,分析了超前小导管注浆效果不明显的主要原因,并为改善注浆效果提出了建议。     

汶川地震灾区城市供水的水质风险和应急处理技术与工艺

对汶川大地震后震区饮用水水源存在的次生污染风险进行分析,其中微生物浓度升高是首要风险,同时还存在大量使用消杀剂引起的杀虫剂污染和水源臭味增强的风险。针对这些风险,开展了一系列应急处理技术的验证性试验,提出了保障性应急处理工艺、强化吸附应急处理工艺和强化氧化应急处理工艺三种方案,以应对可能出现的震后次生水源污染,确保城市饮用水水质安全。     

农业“两区”水利设施建设现状问题及对策

农业"两区"建设是浙江省委、省政府推动农业转型升级、保障粮食安全、发展现代农业的重要举措。水利设施既是农业生产的基础设施,也是现代农业建设中不可或缺的首要条件。在总结浙江省农业"两区"水利设施特征及建设任务的基础上,从水利设施建设管理的主要环节(前期规划、建设程序、经费来源、验收标准、建后管护等)入手,分析了现状水利设施建设管理存在的问题,并提出相应的对策与建议。     

高坝风险分析的事件树法

新世纪一批高坝将要在我国开工建设,这对我国的水电能源及国民经济的发展有着不可估量的作用,而高坝建设中,安全性是需要首先保证的。目前对高坝的风险分析方法有主观概率法、客观概率法等。从系统工程的角度出发,采用事件树方法对高坝的风险进行了探索研究,并给出了算例以说明该方法的有效性和实用性。