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Soil erosion and sediment transport in the gullied Loess Plateau:Scale effects and their mechanisms

Science china(Technological Sciences) 2009年第5期52卷 1283-1292页

作者： LI TieJian1,WANG GuangQian1,XUE Hai2,3 & WANG Kai4.1 State Key Laboratory of Hydroscience and Engineering,Tsinghua University,Beijing 100084.china 2 Yellow River Engineering Consulting Co.,Ltd.,zhengzhou 4.0003,china 3 north china Institute of water conservancy and hydropower,zhengzhou 4.0008,china 4.china Institute of water Resources and hydropower Research,Beijing 100038,china 1. State Key Laboratory of Hydroscience and Engineering Tsinghua University Beijing 100084 China 2. Yellow River Engineering Consulting Co. Ltd. Zhengzhou 450003 China 3. north china Institute of water conservancy and {4. Zhengzhou 450008 China 4. china Institute of water Resources and hydropower Research Beijing 100038 China

Scale effects exist in the whole process of rainfall-3-runoff-3-soil erosion-3-sediment transport in river basins. The differences of hydrographs and sediment graphs in different positions in a river basin are treated as basic scale effects, which are more complex in the gullied Loess Plateau, a region notorious for high intensity soil erosion and hyper-concentrated sediment-laden flow. The up-scaling method of direct extrapolation that maintains dynamical mechanism effective in large scale application was chosen as the methodology of this paper. Firstly, scale effects of hydrographs and sediment graphs were analyzed by using field data, and key sub-processes and their mechanisms contributing to scale effects were clearly defined. Then, the Digital Yellow River Model that integrates sub-models for the subprocesses was used with high resolution to simulate rainfall-3-runoff-3-soil erosion-3-sediment transport response in Chabagou watershed, and the distributed results representing scale effects were obtained. Finally, analysis on the simulation results was carried out. It was shown that gravitational erosion and hyper-concentrated flow contribute most to the spatial variation of hydrographs and sediment graphs in the spatial scale. Different spatial scale distributions and superposition of different sub-processes are the mechanisms of scale effects.

关键词： scale effect soil erosion hyper-concentrated sediment-laden flow the Loess Plateau

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Jackson type theorems on complex curves

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Science china Mathematics 2009年第3期52卷 493-506页

作者： TU TianLiang Deptartment of Mathematics and Informatics, north china Institute of water conservancy and Hydroelectric Power, {4. 4.0011, china Deptartment of Mathematics and Informatics North China Institute of Water Conservancy and Hydroelectric Power Zhengzhou 450011 China

Let Γ be a closed smooth Jordan curve in the complex plane. In this paper, with the help of a class of fundamental functions of Hermite interpolation, the author introduces a continuous function interpolation which uniformly approximates to f(z) ∈ C(Γ ) with the same order of approximation as that in Jackson Theorem 1 on real interval [1, 1]. The accuracy of the order of approximation is proved. Using the method different from the early works, the author studies simultaneous approximation to function and its derivatives and the desired results analogues to that in Jackson Theorem 2 on real interval [1, 1] are obtained.

关键词： complex curves interpolation uniform approximation order of approximation 30E05 30E10 4.A05 4.A25 4.A28

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Experimental Research on Shear Behavior of Reinforced Concrete Composite Beams Under Uniformly Distributed Load

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china Ocean Engineering 1998年第4期13卷 467-476页

作者： ZHAO Shunbo Ass. Prof., north china Institute of water conservancy and Hydroelectric Power, {4. 4.004., P. R. china. N. china Inst. water Conserv./H.P. Zhengzhou 450045 China

An experimental program was carried out to study the shear behavior of the reinforced concrete composite beam (RCCB) subjected to two-phase uniformly distributed load. A total of 12 reinforced concrete composite beams were tested: 10 of them were the RCCB subjected to two-phase uniformly distributed load, the other 2 were the comparative reinforced concrete beams cast at the same time as the RCCB subjected to one-phase uniformly distributed load. The interface of precast unit and recast concrete was natural and rough. The test range of the main composite factors: the ratio of precast section depth to composite section depth was from 0.35 to 0.65, the ratio of first-phase load moment to precast section ultimate bearing moment was from 0.25 to 0.65. Based on the test results, the stresses of the longitudinal reinforcements and stirrups, the load-bearing properties of the interface, the crack state and the failure characteristics of the RCCB under uniformly distributed load are discussed. The effects of the stirrups, the concrete strength and the composite factors on the shear resistance of the RCCB are analyzed, and the method for evaluating the shear resistance of the RCCB is proposed.

关键词： reinforced concrete composite beam shear resistance composite factor mechanism of failure

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Thermal Conductivity and Heat Transfer Coefficient of Concrete

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Journal of Wuhan University of Technology(Materials Science) 2011年第4期26卷 791-796页

作者：郭利霞 north china University of water Resources and Electric Power

A very simple model for predicting thermal conductivity based on its definiensis was presented. The thermal conductivity obtained using the model provided a good coincidence to the investigations performed by other authors. The heat transfer coefficient was determined by inverse analysis using the temperature measurements. From experimental results, it is noted that heat transfer coefficient increases with the increase of wind velocity and relative humidity, a prediction equation on heat transfer coefficient about wind velocity and relative humidity is given.

关键词： thermal conductivity heat transfer coefficient relative humidity wind velocity

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Transport Properties of LCMO Granular Films Deposited by the Pulsed Electron Deposition Technique

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Journal of Wuhan University of Technology(Materials Science) 2011年第6期26卷 1027-1031页

作者：陈雷明 zhengzhou Institute of Aeronautical Industry Management

By finely controlling the deposition parameters in the pulsed electron deposition process, granular La 2/3 Ca 1/3 MnO 3 （LCMO） film was grown on silicon substrates. The substrate temperature, ambient pressure in the deposition chamber and acceleration potential for the electron beam were all found to affect the grain size of the film, resulting in different morphologies of the samples. Transport properties of the obtained granular films, especially the magnetoresistance （MR）, were studied. Prominent low-field MR was observed in all samples, indicating the forming of grain boundaries in the sample. The low-field MR show great sensitive to the morphology evolution, which reaches the highest value of about 4.% for the sample with the grain size of about 250 nm. More interestingly, positive-MR （p-MR） was also detected above 300 K when low magnetic field applying, whereas it disappeared with higher magnetic field applied up to 1.5 and 2 Tesla. Instead of the spin- polarized tunneling process being commonly regarded as a responsible reason, lattice mismatch between LCMO film and silicon substrate appears to be the origin of the p-MR

关键词： colossal magnetoresistance granular film transport properties

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Risk analysis model for landslide mass of high slope in dam area

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Science china(Technological Sciences) 2008年第S2期51卷 25-31页

作者： GU ChongShi1,2,HE XianFeng3,4.WU ZhongRu1,2 & SU HuaiZhi1,2 1 College of water conservancy and hydropower Engineering,Hohai University,Nanjing 210098,china 2 National Engineering Research Center of water Resources Efficient Utilization and Engineering Safety,Nanjing 210098,china 3 Yellow River Institute of Hydraulic Research,zhengzhou 4.0003,china 4.Embankment Security Defect Prevention and Control Engineering Research Center of MWR,zhengzhou 4.0003,china 1. College of water conservancy and hydropower Engineering Hohai University Nanjing 210098 China 2. National Engineering Research Center of water Resources Efficient Utilization and Engineering Safety Nanjing 210098 China 3. Yellow River Institute of Hydraulic Research Zhengzhou 450003 China 4. Embankment Security Defect Prevention and Control Engineering Research Center of MWR Zhengzhou 450003 China

In order to identify the threat of reservoir bank landslide to dam safety and reduce the risk of dam failure,impact factors of the landslide are *** concept of landslide risk degree is put forward to measure the threat of landslide to dam *** monotony of the landslide risk assessment function which changes with different affecting factors is analyzed *** on gene automatic programming,a data mining model of the landslide risk assessment function is constructed combined with impact factors of reservoir bank landslide on dam *** the assessment function of landslide risk has been excavated and established according to practical project information,which provides a valuable reference for analyzing the impact of landslide on dam risk.

关键词： landslide dam failure risk landslide risk

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Unified solutions for stresses and displacements around circular tunnels using the Unified Strength Theory

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Science china(Technological Sciences) 2010年第6期53卷 1694-1699页

作者： ZHANG ChangGuang1,WANG JiangFeng2 & ZHAO JunHai3 1 Department of Geotechnical Engineering,Tongji University,Shanghai 200092,china 2 north china Institute of water {4. and Hydroelectric Power,zhengzhou 4.0011,china 3 School of Civil Engineering,Chang’an University,Xi’an 710061,china 1. Department of Geotechnical Engineering Tongji University Shanghai 200092 China2. North China Institute of Water Conservancy and Hydroelectric Power Zhengzhou 450011 China3. School of Civil Engineering Chang’an University Xi’an 710061 China

The unified solutions are presented for stresses and displacements around a circular tunnel subjected to a hydrostatic stress *** rock mass is assumed to be elastic-brittle-plastic and governed by the Unified Strength *** displacements are obtained accounting for three different definitions for elastic strains and different Young's modulus in the plastic *** unified solutions obtained in this paper are especially versatile in reflecting the intermediate principal stress effect to different extents for different *** conventional solutions,based on the Mohr-Coulomb failure criterion and the Generalized Twin Shear Stress yield criterion,are special cases of the present unified *** new unified solutions can compare with those computed by the latest generalized Hoek-Brown failure *** results obtained demonstrate the importance of the intermediate principal stress influence for the stresses and displacements *** effects of different definitions for elastic strains and different Young's modulus in the plastic zone on the displacements are significant.

关键词： Unified Strength Theory intermediate principal stress different definitions for elastic strains different Young’s modulus

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Efficiency of sediment transport by flood and its control in the Lower Yellow River

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Science china(Technological Sciences) 2004年第z1期47卷 173-185页

作者： NI Jinren1, LIU Xiaoyong2, LI Tianhong1, ZHAO Ye’an3 & JIN Ling1 1. Department of Environmental Engineering, Peking University The Key Laboratory of water and Sedi- ment Sciences, Ministry of Education, Beijing 100871, china 2. General Institute of water Resources and hydropower Planning and Design, Ministry of water Re- sources, Beijing 100011, china 3. The Yellow River conservancy Commission, zhengzhou 4.0003, china 1. Department of Environmental Engineering Peking University 100871 Beijing China 2. The Key Laboratory of water and Sediment Sciences Ministry of Education 100871 Beijing China 3. General Institute of water Resources and hydropower Planning and Design Ministry of Water Resources 100011 Beijing China 4. The Yellow River conservancy Commission 450003 Zhengzhou China

This paper presents the characteristics of sediment transport by flood in the Lower Yellow River with the reach from Huayuankou to Gaocun, which is regarded as a typical braided pattern. The Artificial Neural Network Model on water Use for Sediment Transport (WUST) by flood was established based on the measured data from 1980 to 1998. Consequently, simulations of controlling process of sediment transport by flood were made in terms of the control theory under different scenarios. According to the situation of sediment transport by flood in the Lower Yellow River, Open-Loop control system and feedback control system were adopted in system design. In the Open-Loop control system, numerical simulations were made to reveal the relationship between average discharge of flood and the WUST with varying sediment concentrations. The results demonstrate that sediment concentration has significant influence on the controlling process of flood flow to WUST. It is practical and efficient to control WUST if sediment concentration is less than 20 kg/m3. In the feedback control system, controlling processes of sediment concentration and flood discharge for sediment transport were simulated respectively under given conditions, and it was found that sediment transport process could be controlled completely by sediment concentration and discharge at the inlet of the reach from Huayuankou to Gaocun. Using the same method, controlling processes of sediment transport by flood in other reaches in the Lower Yellow River were also simulated. For the case of sediment concentration being 20 kg/m3, the optimized controlling discharge ranges from 2390 to 2900 m3/s in the lower reach of Huayuankou. This study is also of significance to flood control and flushing sediment in the Lower Yellow River with proper operation modes of Xiaolangdi Reservoir.

关键词： the Lower Yellow River, flood, sediment transport, efficiency, simulation, control.

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Synergetic-bifurcated prediction model of slope occurrence and its application

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Science china(Technological Sciences) 2003年第z1期46卷 69-77页

作者： HUANG Zhiquan & WANG Sijing north china Institute of water conservancy and Hydroelectric Power, {4., china Institute of Geology & Geophysics, Chinese Academy of Sciences, Beijing 100029, china N china Inst water conservancy & Hydroelect Power Zhengzhou 450008 Peoples R China Chinese Acad Sci Inst Geol & Geophys Beijing 100029 Peoples R China

Landslide prediction is one of the most important aspects of prevention and control for geological hazards and the environmental protection. In order to study the nonlinear methods for landslide prediction, the synergetic-bifurcated model of predicting the timing of slope failure is established by combining Synergetics with Bifurcation Theory based on single-state variable friction law in this paper. The synergetic effects and bifurcated process of the factors in the slope evolution can be characterized in the model. Taking the Xintan Landslide as an example, the prediction of landslide is carried out based on the model suggested.

关键词： friction law, landslide, synergetic-bifurcated model, time prediction.

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NUMERICAL SIMULATIONS OF THE HYDRAULIC CHARACTERISTICS OF SIDE INLET/OUTLETS

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Journal of Hydrodynamics 2011年第1期23卷 48-54页

作者： YE Fei GAO Xue-ping north china University of water conservancy and Electric Power Zhengzhou 450011 China School of Civil Engineering Tianjin University Tianjin 300072 China

The hydraulic characteristics at the side inlet/outlet of pumped storage plants is studied by numerical simulations,covering the flow distribution,head loss,vortex,and *** on the physical model test,the realizable k-εturbulence model is used in the 3-D simulation of the side inlet/outlet.A new scheme is suggested to obtain the uneven flow distribution over three branch *** variation of the free surface with the reservoir water level under the pumped condition is simulated,with results consistent with the experimental results.

关键词： hydraulic characteristics side inlet/outlet pumped storage plant numerical simulation realizable k-εturbulence model

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