检索结果-南通市图书馆

Science china(Technological Sciences) 2011年第S1期54卷 54-63页

作者： LI RuoNan 1,CHEN QiuWen 1,2 & Duan Chen 1,3 1 research Center for Eco-environmental Science,Chinese Academy of Sciences,Beijing 100085,china 2 china Three Gorges University,Yichang 443002,china 3 hydraulics department,changjiang river scientific research institute,wuhan 430010,china research Center for Eco-environmental Science Chinese Academy of Sciences china Three Gorges University hydraulics department Changjiang River Scientific Research Institute

Hydropower development changes the river hydrological regime,thereby altering river ecosystem *** important measure for reducing degradation of ecosystem is to determine ecological flow and implement it by reservoir *** paper described a method to calculate river ecological flow based on fish habitat conservation and applied it to Jinping river Bend of Yalong *** chongi was selected as target species,and the fish habitat model coupling with water environmental model was developed according to the relationship between fish and water environment ***,improved hydraulic habitat suitability index(IHHS) and habitat fragment index(HFI) varying with discharge were discussed in this *** area representing average annual flow was taken as a reference,and then ecological hydrographs under different habitat conservation levels were calculated considering season variation and life stages of *** to the natural condition,the model results indicated that the reservoir operation clearly influenced the habitat of the target *** was proposed to ensure flow releases to maintain 70%-90% habitat in section after joint while about 60% before joint.

关键词： river habitat habitat assessment ecological flow ecological hydrograph

EXPERIMENTAL STUDIES ON FREQUENCY CHARACTERISTICS OF THE FLUCTUATING PRESSURE ACTING ON THE APRON OF STILLING BASINS WITH LOW FROUDE NUMBER

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 1992年第4期4卷 21-26页

作者： Ding Zhuo-yi Yangtze river scientific research institute,wuhan Hubei 430010,P.R.china Yangtze river scientific research Inst Wuhan China

Using four types of stilling basin models,this paper studies frequency characteris- tics of the fluctuating pressure acting on the stilling basin apron when Froude number is not greater than *** testing results show that the frequency of fluctuating pressure,f_s in the ranges of 0. 4Hz≤f_s≤1.1Hz.0.2Hz≤f_s≤2.5Hz and 0.4Hz≤f_s≤*** be used as the design frequency corresponding to three patterns of hydraulic *** reliability of f_s for three jump patterns is all nearly equal to 90%.

关键词： frequency characteristics fluctuating pressure stilling basin apron

A 2-D HYDRODYNAMIC MODEL FOR THE river,LAKE AND NETWORK SYSTEM IN THE JINGJIANG REACH ON THE UNSTRUCTURED QUADRANGLES

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2010年第3期22卷 419-429页

作者： ZHANG Xi-bing HU De-chao WANG Min State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan University Wuhan430072 China Yangtze river scientific research institute Wuhan 430010 China State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China

The main river, the Dongting Lake and river networks in the Jingjiang reach of the Yangtze river constitute a complex water system, for which a full 2-D hydrodynamic model is established instead of the traditional 1-D or compound models for simulation of such complex systems, based on the latest developments of computer technologies and numerical methods. To better handle irregular boundaries and keep the computation cost well in a reasonable limit, unstructured grids of moderate scale are used. In addition, a dynamic boundary tracking method is proposed to simulate variable flow domains at different floods, especially, when the moderate scale gird can not describe flows in narrow river-network channels at low water levels. The t9 semi-implicit method and the Eulerian-Lagrangian Method （ELM） are adopted, which make the model unconditionally stable with respect to the gravity wave speed and Courant number restrictions. Properties and efficiency of the model are discussed, and it is concluded that the new model is robust and efficient enough for the simulation of a big, complex water system. Validation tests show that the simulation results agree well with field data. It takes about 0.96 h to complete the computation of a 76 d flood, which indicates that the model is efficient enough for engineering applications.

关键词： 2-D numerical model river network unstructured grid semi-implicit Eulerian-Lagrangian Method (ELM) boundarytracking

2－D　SIMULATION　OF　OPEN　CHANNEL　TURBULENT　FLOW　WITH　HIGH　REYNOLDS　NUMBER　BY　EMPLOYING　N－S　EQUATIONS　AND　IEM

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 1996年第1期8卷 44-51页

作者： Wang Ding-yang Liu He-dong(Yangtze river scientific research institute, wuhan 430010, P. R. china) Yangtze river scientific research Inst Wuhan China

Since 1986, we have been studying the topic of simulating open channel turbulent flow, especially the back flow in extended section, by directly employing N-S equations. Now a breakthrough may be obtained. The simulat... 详细信息

关键词： turbulent flow open channel flow N-S equation.

Anti-Crack Performance of Low-Heat Portland Cement Concrete

在线全文

学校读者我要写书评

暂无评论

Journal of wuhan University of Technology(Materials Science) 2007年第3期22卷 555-559页

作者：杨华全 changjiang river scientific research institute

The properties of low-heat Portland cement concrete（LHC） were studied in detail. The experimental results show that the LHC concrete has characteristics of a higher physical mechanical behavior, deformation and durability. Compared with moderate-heat Portland cement（MHC）, the average hydration heat of LHC concrete is reduced by about 17.5%. Under same mixing proportion, the adiabatic temperature rise of LHC concrete was reduced by 2 ℃-3 ℃,and the limits tension of LHC concrete was increased by 10× 10^-6-15×10^-6 than that of MHC. Moreover, it is indicated that LHC concrete has a better anti-crack behavior than MHC concrete.

关键词： low-heat portland cement mass concrete high crack resistance moderate-heat portland cement

Flood and Waterlogging Disaster Damage Evaluation in Middle-Lower Yangtze river by 3S technology

在线全文

学校读者我要写书评

暂无评论

人民长江 2001年第Z1期32卷 50-52页

作者： ZHAN Xiao-guoEngineer, Yangtze river scientific research institute, wuhan 430010,china TAN De-baoSenior Engineer, Yangtze river scientific research institute, wuhan 430010,china Engineer Yangtze River Scientific Research Institute Senior Engineer Yangtze River Scientific Research Institute

The evaluation method, model and process for the flood and waterlogging disaster condition by GIS,RS and GPS technology and the method for setting up disaster condition database, dyke database and historical disaster damage database are presented. An index of flood damage degree(FDD) used to evaluate the relative degree of disaster loss and divide flood and waterlogging area is suggested. The value of flood damage degree can be calculated as follows :taking the various disaster losses of sample area in a base year as standard value and computing the ratios of various disaster loss values in different areas and years to the standard flood disaster loss values, then summing up the weighted ratios. The computed results are the value of flood damage degree in the every year. The macroscopic flood disaster distribution can be evaluated by the values of flood loss degree.

关键词： flood and waterlogging disaster evaluation method 3S(GIS RS GPS) flood damage degree middle-lower reaches of Yangtze river

Non-uniform sediment incipient velocity

在线全文

学校读者我要写书评

暂无评论

International Journal of Sediment research 2008年第1期23卷 69-75页

作者： Haitao XU1, Jinyou LU2, and Xiaobin LIU11 Master,Yangtze river scientific research Insitute, wuhan 430010, china. 2 Prof., Yangtze river scientific research Insitute, wuhan 430010, china Master Yangtze River Scientific Research Insitute Wuhan 430010 China Prof. Yangtze River Scientific Research Insitute Wuhan 430010 China

Based on the mechanism of non-uniform sediment incipient motion, the dragging force and uplift force coefficient expressions are put forward for the non-uniform bed material exposure and close alignment state. The incipient velocity formula of the non-uniform sediment is then established. It is shown that the formula structure is reasonable, and fine particles of the non-uniform sediment are more difficult to set into motion than the same sized uniform particles, whereas coarser particles are easier to set into motion than their uniform equivalents. The validity of the formula is verified by field and experiment data.

关键词： Non-uniform sediment motion Bed material distribution Incipient velocity

Preliminary Study in Spatial Data Warehouse of Flood Control and Disaster Mitigation in Yangtze river Basin

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

人民长江 2002年第Z1期33卷 90-92页

作者： ZHAN Xiao guoSenior engineer, Yangtze river scientific research institute, changjiang Water Resources Commission, wuhan 430010, china Senior engineer Yangtze River Scientific Research Institute Changjiang Water Resources Commission Wuhan 430010 China

Since 1990s,the spatial data warehouse technology has rapidly been developing, but due to the complexity of multi-dimensional analysis, extensive application of the spatial data warehouse technology is affected. In the light of the characteristics of the flood control and disaster mitigation in the Yangtze river basin, it is proposed to design a scheme about the subjects and data distribution of the spatial data warehouse of the flood control and disaster mitigation in Yangtze river basin, i.e., to adopt a distributed scheme. The creation and development of the spatial data warehouse of the flood control and disaster mitigation in Yangtze river basin is presented .The necessity and urgency of establishing the spatial data warehouse is expounded from the viewpoint of the present situation being short of available information for the flood control and disaster mitigation in Yangtze river basin.

关键词： spatial data warehouse distributional scheme flood control and disaster mitigation Yangtze river

IMPACTS OF THE SOUTH-TO-NORTH WATER DIVERSION PROJECTS (MIDDLE ROUTE)ON THE WATER ENVIRONMENT OF THE MIDDLE AND LOWER REACHES OF THE HANJIANG river

在线全文

学校读者我要写书评

暂无评论

水生生物学报 2006年第6期30卷 643-646页

作者： FAN Bei-Lin, WAN Jian-Rong, ZHANG Jie and LIN Qiu-Sheng (Yangtze river scientific research institute,river research Deparment, wuhan 430010,china) Yangtze river scientific research institute River Research Deparment Wuhan 430010

In this paper, according to the rule of unbalanced sediment transport and the analysis of field data, different water diversion schemes were theoretically studied, including the erosion and sedimentation trend as well as their impacts on the environment of the middle and lower reaches of the Hanjiang river. The results showed that the 95×10 8m 3 water diversion scheme will cause less erosion and water level decrease than the 15×10 8m 3 water diversion scheme. Using a water diversion scheme of 95×10 8m 3, the decrease of water quantity can impact the river hydrodynamic regime substantially and the environments of the middle and lower reaches of the Hanjiang river will be greatly affected. It is therefore necessary to develop new water resources or build projects to meet the need of the environment and the needs for navigation.

关键词： South-to-North Water Diversion Project river regime Water environment Mathematical model

STUDIES ON PROPERTIES OF FLOW CAVITATION NUMBER AND MINIMUM PRESSURE COEFFICIENT IN SHORT CLOSED CONDUITS

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 1994年第3期6卷 1-6页

作者： Ding Zhuo-yiYangtze river scientific research institute, wuhan 430010, P. R. china

For a short closed conduit with smooth (streamline pattern) boundary, the comparison of minimum pressure coefficient at boundary, - Cpm , which obtained from model tests, with flow cavitation number a is possible to describe the property of preventing cavitation in the closed conduit.In this paper, analytical results show that the ratio σ/ - Cpm decreases with increasing Reynolds number Re, when the configuration of the conduit is designed, and this ratio approaches a constant when Re = 106 or so. The model test data for five engineering cases of the short closed conduit with various configuration indicates that the analytical results are reliable. Therefore, the value of the ratio σ/ - Cpm corresponding to that of Reynolds number in model (Re)m ≥106 must be taken so as to correctly describe the cavitation property of the studied conduit. The condition of Lr ≥ 10-4[(Re)p]2/3 should be satisfied ( Lr is model length scale; (Re)p is Reynolds number in prototype) when the model is designed by Froude criterion of similarity.

关键词： cavitation number minimum pressure coefficient conduit.