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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 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

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

Microstructure and cutting performance of Ti(C, N)-based cermets heat-treated in nitrogen

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Rare Metals 2007年第4期26卷 352-358页

作者： LIU Wenjun XIONG Weihao ZHENG Yong SHI Zengmin YE Jiajian State Key Laboratory of Plastic Forming Simulation and Die ＆ Mould Technology of china Huazhong University of Science ＆ Technology Wuhan 430074 China china three gorges university Yichang 443002 China Nanjing university of Aeronautics and Aslronautics Nanjing 210016 China

Ti（C, N）-based cermets were treated using hot isostatic pressing （HIP） at 1423 K in nitrogen. The microstructures compared with the as-sintered cermets were investigated using X-ray diffraction, scanning electron microscopy, transmission electron microscopy, energy-dispersive X-ray analysis, and electron microprobe analysis. It was found that high nitrogen activity in the surface zone resulted in the formation of gradient structure. Approximately 20-1am-deep, nitrogen-rich and titanium-rich hard surface zone was introduced by the heat treatment. The nitrogen activity was the driving force that caused the transportation of the atoms through the binder, titanium towards the surface, and tungsten and molybdenum inwards. In the surface zone, the particle size became fine, the inner rim disappeared, and the volume fraction of the outer rim and the binder phase considerably reduced. Small grains of TiN, WC, Mo2C, and nitrogen-rich carbonitlide phases formed in the surface zone during the heat treatment, improving the tlibological property of the heat-treated cermet.

关键词： Ti(C, N)-based cermets heat-treatment in nitrogen microstructure mechanical properties

基于RIA和云计算的雅砻江流域梯级生态调度决策支持系统

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水电站机电技术 2011年第3期34卷 70-73,128页

作者：徐刚李绍才孙海龙三峡大学湖北宜昌443002 四川大学四川成都610065

以雅砻江流域梯级水电站群生态调度决策支持系统为背景,分析流域梯级水电站群生态调度原则,研究生态流量计算方法,建立生态调度模型,提出水电站群生态调度决策方法,探讨构建该决策系统的解决方案和关键技术。以RIA(Rich Internet Applic... 详细信息

以雅砻江流域梯级水电站群生态调度决策支持系统为背景,分析流域梯级水电站群生态调度原则,研究生态流量计算方法,建立生态调度模型,提出水电站群生态调度决策方法,探讨构建该决策系统的解决方案和关键技术。以RIA(Rich Internet Applications)为平台建立基于云计算的分布式、可扩展的生态调度决策支持系统。

关键词： RIA 云计算决策支持系统生态调度

Fault diagnosis based on high-gain observer with an update law for a class of nonlinear systems

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控制理论与应用（英文版） 2010年第4期8卷 447-452页

作者： Yanjun SHEN (College of Science,china three gorges university,yichang Hubei 443002,china) College of Science China Three Gorges University Yichang Hubei China

In this paper,by using the well-known high-gain observer design,an update law for the gain and an adaptive estimation of parameters,a new method of fault diagnosis for a class of nonlinear systems is *** resort to any transformation for the parameters,the estimation errors of the states and the parameters are guaranteed to be globally exponentially convergent by a persistent excitation *** to the existing results,it can be applied to nonlinear systems with nonlinear terms admitting an incremental rate depending on the measured output.A case study further verifies the validity of the proposed research.

关键词： Fault diagnosis Adaptive estimation High-gain observer Nonlinear systems

Coupling analysis of unsteady seepage and stress fields in discrete fractures network of rock mass in dam foundation

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Science china(Technological Sciences) 2011年第S1期54卷 133-139页

作者： CHAI JunRui 1,2 & XU WeiSheng 2 1 College of Hydraulic and Environmental Engineering,china three gorges university,yichang 443002,china 2 College of Hydropower Engineering,Xi’an university of Technology,Xi’an 710048,china 1. College of Hydraulic and Environmental Engineering China Three Gorges University Yichang 443002 China2. College of Hydropower Engineering Xi’an University of Technology Xi’an 710048 China

The drag force of water flow through single fracture and the coupling characteristics of seepage and stress in single fracture surface are analyzed,and a three dimensional model of coupled unsteady seepage and stress fields is *** model is used to the analysis of foundation rock mass of a high *** the coupling effects are considered,the changes of boundary heads have less influence on the inner head of rock mass,and the strong permeability of main fractures *** the coupling effects are not considered,the fractures distribution affects the inner head more *** the upstream water head declines,the inner head of dam foundation slightly declines and the hydraulic gradient distribution becomes smoother.A bigger upstream water level declining velocity has a stronger lag effect,meanwhile the values of stress components change more *** the upstream water level declining velocity directly affects the stability of rock mass in dam foundation and we should take into account the above factors to make sure the safety of the dam during reservoir level fluctuation period.

关键词： hydraulic engineering unsteady seepage stress coupling fractures network rock mass

Research on forecasting model of sandstone deformation rate during sine wave loading segment under the lag effect

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Science china(Technological Sciences) 2010年第5期53卷 1442-1449页

作者： LIU Jie1,2,LI JianLin1,2,QU JianJun1,ZHOU JiFang3,ZHANG ChaoFeng3 & LI JianWu1 1Key Laboratory of Geological Hazards on three gorges Reservoir Area,Ministry of Education,china three gorges university,yichang 443002,china 2College of Civil and Hydropower Engineering,china three gorges university,yichang 443002,china 3Er’tan Hydropower Development Company,Ltd.Chengdu 61000,china 1. Key Laboratory of Geological Hazards on three gorges Reservoir Area Ministry of Education China Three Gorges University Yichang 443002 China2. College of Civil and Hydropower Engineering China Three Gorges University Yichang 443002 China3. Er’ tan Hydropower Development Company Ltd. Chengdu 61000 China

To reduce data variance caused by individual differences of different samples,a new experimental method is proposed by loading and unloading the axial forces with different frequencies and different waves of a certain load amplitude to the same rock sample without damaging *** time segments are defined and fractionized into segments I and Ⅱ.Criterions for seg-mentation,definitions of relevant parameters and empirical analysis are also offered *** the course of sinusoidal loading,the serious peak value dislocation of the displacement variation rate and the loading rate is defined as peak ***,the definition of the apparent tangent modulus is put forward and the linear relation between it and the vertical force in the frequency of 0.1,0.2,0.5 Hz sinusoidal loading segment is confirmed to be ever-present on the basis of the test *** the calculating formula of the deformation rate in non-lag time is *** is thus suggested that the deformation rate should be codetermined by the loading rate df/dt and instant load f(t),which well explains the peak dislocation of the time-variable curve peak value of dl/dt and deformation rate of df/*** the lag time derivation model is established and by comparing the calculated values with the measured ones,it is demonstrated that the above formula offers a better simulation of the sandstone deformation rate in the sinusoidal loading segment,with the load amplitude being 96 kN and the frequency ranging from 0.1 Hz to 0.5 Hz.

关键词： lag time segments peak shifting phenomenon apparent tangent modulus deformation rate

CIRCULAR CHROMATIC NUMBER AND MYCIELSKI GRAPHS

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Acta Mathematica Scientia 2006年第2期26卷 314-320页

作者：刘红美 College of Science three gorges university Yichang 443002China

For a general graph G, M（G） denotes its Mycielski graph. This article gives a number of new sufficient conditions for G to have the circular chromatic number xc（M（G）） equals to the chromatic number x（M（G））, ... 详细信息

关键词： Circular chromatic number Mycielski graphs chromatic number

Congruence Permutable Kleene-Stone Algebras

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Wuhan university Journal of Natural Sciences 2010年第2期15卷 99-102页

作者： LUO Congwen, WANG Gaoxia Department of Mathematics, china three gorges university, yichang 443002, Hubei, china Department of Mathematics China Three Gorges University Yichang China

A Kleene-Stone algebra is a bounded distributive lattice with two unary operations that make it a Kleene and a Stone algebra. In this paper, we study the properties of the prime ideals in a Kleene-Stone algebra and characterize the class of Kleene-Stone algebras that are congruence permutable by means of the dual space of a Kleene-Stone algebra and then show that a finite Kleene-Stone algebra is congruence permutable if and only if it is isomorphic to a direct product of finitely many simple algebras.

关键词： Kleene-Stone algebra Kleene-Stone space congruence permutable

The feature study on the π and proton rapidity distributions at AGS, SPS and RHIC

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Science china(Physics,Mechanics & Astronomy) 2009年第2期52卷 198-206页

作者： FENG ShengQin1,2 & YUAN XianBao1,3 1 College of Science, china three gorges university, yichang 443002, china 2 School of Physics and Technology, Wuhan university, Wuhan 430072, china 3 Institute of Particle Physics, Central china Normal university, Wuhan 430070, china 1. College of Science China Three Gorges University Yichang 443002 China 2. School of Physics and Technology Wuhan University Wuhan 430072 China 3. Institute of Particle Physics Central China Normal University Wuhan 430070 China

The features of nuclear stopping power and multi-hadron production systematically are studied by making an analysis of rapidity distributions of pion and proton at AGS, SPS and RHIC in this work. It is found that nuclear stopping power increases linearly with project rapidity yp at AGS and SPS, but that is not liner at RHIC. It is argued that the average rapidity loss is saturated at central rapidity region at RHIC. For pion distribution, it is found that the phase space of pion distribution distributes uniformly in the longitudinal direction,and a linear relationship of L with log s is given at AGS and SPS. Non-uniform flow model may explain the features of the distribution at AGS and SPS, but may not ex- plain those of at RHIC.

关键词： non-uniform flow model average rapidity loss baryon number density nuclear stopping power

Anisotropic damage coupled modeling of saturated porous rock

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Science china(Technological Sciences) 2010年第10期53卷 2681-2690页

作者： LU YingFa1,2, WU XinXing1,2 & SHAO JianFu3 1 Key Laboratory of Geological Hazards on three gorges Reservoir Area, Ministry of Education, china three gorges university, yichang 443002, china 2 School of Civil Engineering, Wuhan university, Wuhan 430071, china 3 university of Sciences and Technologies of Lille, Lille 59655, France 1. Key Laboratory of Geological Hazards on three gorges Reservoir Area Ministry of Education China Three Gorges University Yichang 443002 China2. School of Civil Engineering Wuhan University Wuhan 430071 China3. University of Sciences and Technologies of Lille Lille 59655 France

It is widely acknowledged that the natural rock mass is anisotropic and its failing type is also non-isotropic. An orthotropic elastic damaged model has been proposed in which the elastic deformation,the damaged deformation and irreversible deformation can be identified respectively. A second rank damage tensor is employed to characterize the induced damage and damage evolution related to the propagation conditions of microcracks. A specific form of the Gibbs free energy function is used to obtain the effective elastic stiffness and the limited scopes of damage parameters are suggested. The model’s parameter determination is proposed by virtue of conventional tri-axial test. Then,the proposed model is developed to simulate the coupled hydraulic mechanical responses and traction behaviors in different loading paths of porous media.

关键词： anisotropy damage modeling saturated rock tensile failure