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| 1 | Influence of the impounding process of the Three Gorges Reservoir up to water level 172.5m on water eutrophication in the Xiangxi Bay显示文摘The water level of the Three Gorges Reservoir(TGR) rose to 172.5 m in two stages from September to November,2008.The hydrodynamic parameters and water quality parameters(e.g.flow velocity,temperature,turbidity and nutrient content) had been continuously monitored to reveal the influence of the impounding process of the TGR on the water eutrophication in the Xiangxi Bay(XXB).The maximal daily rise of the water level of the TGR was about 2.38 m.The water exchange between the mainstream(the Changjiang River) and the XXB of the TGR was enhanced by density current,and its main characteristics were a density-stratified flow in different directions.The water exchange reduced the differences of the water quality parameters(for example,temperature,turbidity,nutrient level,pH,etc.) between the mainstream and the XXB during the impounding process.Meanwhile,the water stability index in the mainstream remained small but it was lowered in the XXB.The main causes included the dilution by water of lower concentration of the chlorophyll a(Chl.a) entering from the mainstream,the decline of the water stability,and the increase of suspended silt,which induced the Chl.a to decrease in the XXB during the impounding process.The grade of the water eutrophication changed from middle eutrophic level to mesotrophic state in the process.However,as available nutrients were imported into the XXB from the mainstream during the impounding process the risk of water eutrophication increases in the XXB in the future. | YANG ZhengJian1,LIU DeFu1,JI DaoBin1,2 & XIAO ShangBin1,3 1 College of Civil & Hydroelectric Engineering,China Three Gorges University,Yichang 443002,China 2 School of Water Resources & Hydropower Engineering,Wuhan University,Wuhan 430072,China 3 Institute of Earth Environment,Chinese Academy of Sciences,Xi’an 710075,China | 2010 | Science China(Technological Sciences)2010,53,4: | 58 |
| 2 | Numerical simulation of mechanisms of deformation,failure and energy dissipation in porous rock media subjected to wave stresses显示文摘The pore characteristics,mineral compositions,physical and mechanical properties of the subarkose sandstones were acquired by means of CT scan,X-ray diffraction and physical tests.A few physical models possessing the same pore characteristics and matrix properties but different porosities compared to the natural sandstones were developed.The 3D finite element models of the rock media with varied porosities were established based on the CT image processing of the physical models and the MIMICS software platform.The failure processes of the porous rock media loaded by the split Hopkinson pressure bar(SHPB) were simulated by satisfying the elastic wave propagation theory.The dynamic responses,stress transition,deformation and failure mechanisms of the porous rock media subjected to the wave stresses were analyzed.It is shown that an explicit and quantitative analysis of the stress,strain and deformation and failure mechanisms of porous rocks under the wave stresses can be achieved by using the developed 3D finite element models.With applied wave stresses of certain amplitude and velocity,no evident pore deformation was observed for the rock media with a porosity less than 15%.The deformation is dominantly the combination of microplasticity(shear strain),cracking(tensile strain) of matrix and coalescence of the cracked regions around pores.Shear stresses lead to microplasticity,while tensile stresses result in cracking of the matrix.Cracking and coalescence of the matrix elements in the neighborhood of pores resulted from the high transverse tensile stress or tensile strain which exceeded the threshold values.The simulation results of stress wave propagation,deformation and failure mechanisms and energy dissipation in porous rock media were in good agreement with the physical tests.The present study provides a reference for analyzing the intrinsic mechanisms of the complex dynamic response,stress transit mode,deformation and failure mechanisms and the disaster mechanisms of rock media. | JU Yang1,2,WANG HuiJie1,YANG YongMing1,HU QinAng3 & PENG RuiDong1 1 State Key Laboratory of Coal Resources and Safe Mining,Beijing Key Laboratory of Fracture and Damage Mechanics of Rock and Concrete,China University of Mining and Technology,Beijing 100083,China 2 Department of Mechanical and Manufacturing Engineering,University of Calgary,Calgary,Alberta,T2N 1N4,Canada 3 School of Environment and Civil Engineering,College of Engineering,Oklahoma State University,Stillwater,OK 74078,USA | 2010 | Science China(Technological Sciences)2010,53,4: | 32 |
| 3 | Modelling of multi-bodies in close proximity under water waves——Fluid resonance in narrow gaps显示文摘Viscous fluid model and potential flow model with and without artificial damping force(f=-μV,μ the damping coefficient and V the local averaging flow velocity) are employed in this work to investigate the phenomenon of fluid resonance in narrow gaps between multi-bodies in close proximity under water waves.The numerical results are compared with experimental data available in the literature.The comparison demonstrates that both the viscous fluid model and the potential flow model are able to predict the resonant frequency reasonably well.However the conventional potential flow model(without artificial damping term) significantly over-predicts the wave height in narrow gaps around the resonant frequency.In order to calibrate the appropriate damping coefficient used for the potential model and make it work as well as the viscous fluid model in predicting the resonant wave height in narrow gaps but with little computational efforts,the dependence of damping coefficient μ on the body geometric dimensions is examined considering the parameters of gap width Bg,body draft D,body breadth ratio Br and body number n(n = 2,3),where Br = BB/BA for the case of two bodies(Body A and Body B) with different breadths of BA and BB,respectively.It was confirmed that the damping coefficient used for the potential flow model is not sensitive to the geometric dimensions and spatial arrangement.It was found that μ∈ [0.4,0.5] may guarantee the variation of Hg/H0 with kh to be generally in good agreement with the experimental data and the results of viscous fluid model,where Hg is the excited wave height in narrow gaps under various dimensionless incident wave frequencies kh,H0 is the incident wave height,k = 2π/L is the wave number and h is the water depth. | LU Lin1,2,TENG Bin3,CHENG Liang 4,SUN Liang5 & CHEN XiaoBo6 1 Center for Deepwater Engineering,Dalian University of Technology,Dalian 116024,China 2 State Key Laboratory of Structural Analysis for Industrial Equipment,Dalian University of Technology,Dalian 116024,China 3 State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China 4 School of Civil and Resource Engineering,The University of Western Australia,Crawly 6003,Australia 5 Centre for Offshore Research and Engineering,Department of Civil Engineering,National University of Singapore,117576,Singapore 6 Research Department,Bureau Veritas,Neuilly-Sur-Seine,92570,France | 2011 | Science China(Physics,Mechanics & Astronomy)2011,54,1: | 29 |
| 4 | Development of Finite Element Limiting Analysis Method and Its Applications in Geotechnical Engineering显示文摘The Finite Element Limiting Analysis Method(LELAM) has the advantage of combining a numerical analysis method with traditional limiting equilibrium methods.It is particularly applicable to the analysis and design of geotechnical engineering.In the early 20th century,FELAM has been developed vigorously in domestic geotechnical engineering over international common finite element procedures.It has made great achievements in basic theory research and computational precision,thus broadening the application fields in practical projects.In order to gradually make innovations in geotechnical design methods,some of our research results are presented,mainly including geotechnical safety factor definitions,the principles for use of the method concerned,the overall failure criterion,the deduction and selection of the yield criterion,and the measurement to improve the computational precision,etc..The application field has been broadened from two-dimensional to three-dimensional,from soil slope to jointed rock slope and foundation,from stable seepage to non-stable seepage,from slope and foundation to tunnel.This method has also been used in search of many hidden sliding surfaces of complex landslides,conducting the structural support design considering the interaction between the soil and the structure,and computing simulation foundation bearing plates load tests,etc.. | Zheng Yingren1,Deng Chujian1,Zhao Shangyi1,Tang Xiangsong1,Liu Mingwei1,Zhang Liming2(1 Department of Civil Engineering,Logistical Engineering University,Chongqing 400041,China 2 Department of Science and Information Engineering,Qingdao Technological University,Qingdao 266033,China) | 2007 | 工程科学(英文版)2007,5,3: | 27 |
| 5 | Damage and progressive failure of concrete structures using non-local peridynamic modeling显示文摘Peridynamics (PD), a recently developed theory of solid mechanics, which employs a non-local model of force interaction and makes use of integral formulation rather than the spatial partial differential equations used in the classical continuum mechanics theory, has shown effectiveness and promise in solving discontinuous problems at both macro and micro scales. In this paper, the peridynamics theory is used to analyze damage and progressive failure of concrete structures. A non-local peridynamic model for a rectangular concrete plate is developed, and a central pairwise force function is introduced to describe the interior interactions between particles within some definite distance. Damage initiation, evolution and crack propagation in the concrete model subject to in-plane uni-axial tension, in-plane uni-axial compression and out-of-plane impact load are investigated respectively. The numerical results show that discontinuities appear and grow spontaneously as part of the solution to the peridynamic equations of motion, and no special failure criteria or re-meshing techniques are required, which proves the potential of peridynamic modeling as a promising technique for analyzing the progressive failure of concrete materials and structures. | HUANG Dan1,2, ZHANG Qing1,2 & QIAO PiZhong1,3 1 State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering, Hohai University, Nanjing 210098, China 2 Department of Engineering Mechanics, Hohai University, Nanjing 210098, China 3 Department of Civil and Environmental Engineering, Washington State University, Pullman, WA 99164-2910, USA | 2011 | Science China(Technological Sciences)2011,54,3: | 24 |
| 6 | Transformation of Compound K from Saponins in Leaves of Panax notoginseng by Immobilized β-Glucanase显示文摘Objective To prepare an active anti-tumor component,compound K(C-K),from saponins in leaves of Panax notoginseng(SLPN) using immobilized β-glucanase.Methods Two entrapments,alginate gel-1(Alg 1) and alginate gel-2(Alg 2),were evaluated for their ability to immobilize β-glucanase.The amount and purity of C-K obtained from the transformation process were analyzed by HPLC,and the immobilizing parameters were optimized.Results β-Glucanase can be immobilized and reused with either of the entrapment.However,using Alg 1 resulted in higher enzyme activity than Alg 2.The optimal concentration of the immobilized enzyme was 10%;The optimal crosslinking time was 4-6 h;and the optimal concentration of the crosslinking agent was 6%- 7%.Conclusion Immobilized β-glucanase shows sustained enzyme activity,good ethanol tolerance,and was reusable for the preparation of C-K from SLPN. | DONG Hui-juan1,2,JIANG Bin-hui3,HAN Ying3,GENG Yong1,ZHAO Yu-qing4 1.Institute of Applied Ecology,Chinese Academy of Sciences,Shenyang 110016,China 2.Graduate School of Chinese Academy of Sciences,Beijing 100039,China 3.School of Resources and Civil Engineering,Northeastern University,Shenyang 110004,China 4.Shenyang Pharmaceutical University,Shenyang 110016,China | 2010 | Chinese Herbal Medicines2010,2,1: | 20 |
| 7 | Theory on real-time control of construction quality and progress and its application to high arc dam显示文摘A complete scheme for solving the key scientific problems associated with high-standard,high-intensity continuous construction of high arch dams was presented. First,based on a coupling analysis of construction system decomposition and coordination for a high arc dam,a mathematical model for real-time control of construction quality and progress that considers complex constraints was developed. Second,a method of progress control was proposed based on a dynamic simulation. Third,a dynamic quality control mechanism was established based on construction information collected using a PDA. Fourth,a system for integrating collected information,progress simulation and quality control analyses under a network environment was developed. Finally,these methods were applied to a practical project to show that each aspect of a construction process can be managed effectively and that real-time monitoring and feedback control can be realized. Our methods provide new theoretical principles and technical measures for quality and progress control in the high arc dam construction process. | ZHONG DengHua1, REN BingYu1, LI MingChao1, WU BinPing1 & LI MingChuan2 1 Department of Hydraulic and Hydroelectric Engineering, School of Civil Engineering, Tianjin University, Tianjin 300072, China 2 Ertan Hydropower Development Company, Ltd., Chengdu 610051, China | 2010 | Science China(Technological Sciences)2010,53,10: | 18 |
| 8 | Full-scale measurements of dynamic response of suspension bridge subjected to environmental loads using GPS technology显示文摘Nowadays, there are many larger and taller engineering structures than in the past. These structures are commonly designed to be more flexible. Thus, they are sensitive to severe wind gust and earthquake tremor. For the dynamic response prediction, finite element (FE) modal updating and structural health monitoring, the dynamic characteristics of a structure are becoming increasingly important. The aim of this paper is to show an emerging tool-the real time kinematic (RTK) global positioning system (GPS), which is used to measure and monitor the low-frequency vibration of Dalian BeiDa Bridge, a medium span suspension bridge. The modal analysis is firstly performed on the developed three-dimensional FE model according to the original blue prints of the bridge to provide the analytical frequencies and mode shapes. The field ambient vibration tests using the accelerometers on the bridge deck are conducted just prior to the use of the GPS system in order to validate the FE model. And then, the calibration test is done to assess the dynamic displacement measurement accuracy of the GPS in three orthogonal directions. The GPS signal properties, such as the amplitude, standard deviations (STD), power spectral density (PSD), and probability density functions (PDF), are studied in details. After that, a structural health monitoring system based on the GPS is devised and installed on the bridge to provide real-time measurement of deck movement. The output-only modal parameter identification is carried out by using the Periodogram method to investigate the responses of the bridge. The result shows that the spectral densities of the displacements measured by the GPS correspond well with the results by the FEM analysis and the accelerometer vibration test. It is concluded that the GPS method is reliable and useful to clarify the ambient vibration response behaviors of the flexible structures. The integration of the GPS and accelerometer methods results in a hybrid arrangement that can help to eliminate some disadvantages of the two devices used separately. | YI TingHua1,2, LI HongNan1 & GU Ming2 1State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian 116024, China 2State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China | 2010 | Science China(Technological Sciences)2010,53,2: | 18 |
| 9 | Recent research and applications of GPS based technology for bridge health monitoring显示文摘Today,long-span bridges are being designed to be more flexible and to resist extensive impacts from changes in temperature,severe wind gusts and earthquake tremors. Structural responses (especially displacement) of bridge structures are becoming increasingly important for the finite element (FE) modal updating,structural response prediction and safety evaluation. Methods of global displacement sensing were developed for these needs. This paper presents an overview of current research and development activities in the field of bridge health monitoring using the global positioning system (GPS). The GPS monitoring technology and its accuracy assessment method are also briefly described. Finally,existing problems and promising research efforts in the GPS based bridge health monitoring are discussed. | YI TingHua1,2, LI HongNan1 & GU Ming2 1 Faculty of Infrastructure Engineering, Dalian University of Technology, Dalian 116023, China 2 State Key Laboratory for Disaster Reduction in Civil Engineering, Tongji University, Shanghai 200092, China | 2010 | Science China(Technological Sciences)2010,53,10: | 18 |
| 10 | Research on nonlinear constitutive relationship of permanent deformation in asphalt pavements显示文摘To predict correctly the rut depths in asphalt pavements,a new nonlinear viscoelastic-elastoplastic constitutive model of permanent deformation in asphalt pave-ments is presented. The model combines a generalized Maxwell model with an elasto-plastic one. Then from the creep theory,the linear and nonlinear constitutive equations of the generalized Maxwell model are obtained. From the nonlinear finite element method for the rutting of the asphalt pavement,the rut depths of 4 asphalt-aggregate mixtures are obtained. And the results are compared with the ones from the finite element method by SHRP and the experiments by SWK/UN. The results in this paper are better than the ones by SHRP,and agree with the ones of the experiment by SWK/UN. This shows that the nonlinear viscoelastic-elastoplastic constitutive model,which is presented in this paper for the rutting of the asphalt pavement,is effective. The properties,such as nonlinear elastic-ity,plasticity,viscoelasticity and nonlinear viscoelasticity,which affect the rutting of an asphalt pavement,can be shown in the model. And the characteristics of the permanent deformation of the asphalt pavement can be presented entirely in the model. | PENG Miaojuan1 & XU Zhihong2 1. Department of Civil Engineering,Shanghai University,Shanghai 200072,China 2. School of Transportation Engineering,Tongji University,Shanghai 200092,China | 2006 | Science China(Physics,Mechanics & Astronomy)2006,49,6: | 16 |
| 11 | Dynamic calculation model and seismic response for frame supporting structure with prestressed anchors显示文摘A dynamic calculation model of frame supporting structures with prestressed anchors for the slope stability is proposed. The frame and soil are closely contacted in the role of prestressed anchors and they cannot be separated along the whole slope. The lateral displacement of frame and soil is nearly in phase. The movement characteristic satisfies the theory of elastic foundation beam. The frame is treated with elastic foundation beam in this model. The influence of prestressed anchors is simplified as linear spring and damped system related with velocity. Under the condition of horizontal earthquake excitation, the equation of vibration response is established by using the model of dynamic Winkler beam and the analytical solutions are obtained for simple harmonic vibration. This method is applied to a case record for illustration of its capability, in order to verify the method, 3D nonlinear FEM (ADINA) is used to analyze the seismic performance of this case, the comparative results show that the design and the analysis are safe and credible by using the proposed method. The calculation model provides a new way for earthquake analysis and seismic design of slope stability supported by frame structure with prestressed anchors. | DONG JianHua1’2, ZHU YanPeng1, ZHOU Yong1 & MA Wei2 1 College of Civil Engineering, Lanzhou University of Technology, Lanzhou 730050, China 2 State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences, Lanzhou 730000, China | 2010 | Science China(Technological Sciences)2010,53,7: | 16 |
| 12 | 徐州大北望寒武系地层中的风暴岩及其特征显示文摘本文在研究了徐州大北望寒武系地层剖面和室内整理的基础上。 | Jin Kankun Hebei College of Civil Science and Technology | 1997 | 岩相古地理1997,17,1: | 16 |
| 13 | Diffraction of plane SV waves by a cavity in poroelastic half-space显示文摘This paper presents an indirect boundary integration equation method for diffraction of plane SV waves by a 2-D cavity in a poroelastic half-space.The Green’s functions of compressive and shear wave sources are derived based on Biot’s theory. The scattered waves are constructed using fi ctitious wave sources close to the boundary of the cavity, and their magnitudes are determined by the boundary conditions. Verifi cation of the accuracy is performed by: (1) checking the satisfaction extent of the boundary conditions, (2) comparing the degenerated solutions of a single-phased case with wellknown solutions, and (3) examining the numerical stability of the solutions. The nature of diffraction of plane SV waves around a cavity in a poroelastic half-space is investigated by numerical examples. | Liang Jianwen and Liu Zhongxian Department of Civil Engineering, Tianjin University, Tianjin 300072, China Professor PhD Candidate | 2009 | Earthquake Engineering and Engineering Vibration2009,8,1: | 15 |
| 14 | NUMERICAL MODELLING OF ROCK FALL USING EXTENDED DDA显示文摘The reasonable design of protective structures to mitigate the hazards from rock fall depends on the knowledge of motion behaviors of falling stones,such as the falling paths,velocities,jump heights and distances.Numerical simulation is an effective way to gain such kind of knowledge,In this paper,the discontinuous deformation analysis (DDA) is applied to rock fall analysis.In order to obtain more reliable results,the following improvements and extensions are made on the original DDA.(1)Solve the problem of block expansions due to rigid body rotation error.(2) Add the function of modeling the drag resistance from air and plants so that the velocities of falling stones obtained by simulations are good enough in agreement with those by experiments in situ.(3)Add the capability to consider energy loss due to block collisions so that the jumping heights and distances obtained by simulations are good enough in agreement with thos by experiments even for the slope with very soft layer on its surface.One of application examples is presented to show that the extended DDA is very effective and useful in rock fall analysis.Therefore,the presented method is expected to be put into wide use in slop stability analysis. | Chen Guangqi (Graduate School of Civil and Structural Engineering, Kyushu University, Fukuoka 816-8581 Japan) | 2003 | 岩石力学与工程学报2003,22,6: | 14 |
| 15 | Quick image-processing method of UAV without control points data in earthquake disaster area显示文摘The methods of unmanned aerial vehicles images splicing rapidly and rectifying without control points data, only using auxiliary data recorded by unmanned aerial vehicle (UAV) system, were researched. Two algorithms were proposed, including UAV images auto- splicing rapidly after image blocking and UAV images rectifying based on pseudo center points of auxiliary data. When SIFT algorithm for UAV images splicing is applied, the accuracy is very high, but the efficiency is very low. The splicing efficiency is improved greatly based on SIFT algorithm after image blocking. The results show that rectifying accuracy is very high and has no visual dislocation when pseudo center points of auxiliary data is applied. | LI Chang-chun1, ZHANG Guang-sheng1, LEI Tian-jie2, 3, GONG A-du2, 3 1. School of Surveying & Land Information Engineering, Henan Polytechnic University, Jiaozuo 454000, China 2. Key Laboratory of Environmental Change and Natural Disaster, Ministry of Education, Beijing Normal University, Beijing 100875, China 3. Ministry of Civil Affairs/Ministry of Education of China Academy of Disaster Reduction and Emergency Management, Beijing Normal University, Beijing 100875, China | 2011 | 中国有色金属学会会刊:英文版2011,21,S3: | 13 |
| 16 | A MODEL FOR CONCRETE DURABILITY DEGRADATION IN FREEZE-THAWING CYCLES显示文摘Up to now, how to control the durability of concrete structures is still a pending research topic in civil engineering. Owing to the fact that concrete durability can be affected by many non-mechanical factors, it is very difficult to research durability only based on mechanics.However, the phenomenon of failure caused by non-mechanical factors is similar to that caused by loads. As frost durability reflects the comprehensive durability of concrete in a certain sense,the specific failure process is analyzed and a damage model is introduced, which can describe the durability degradation process of concrete in the whole freeze-thawing cycle. | Wei Jtm Wu Xinghao Zhao Xiaolong (School of Civil Engineering and Mechanics,Huazhong University of Science and Technology,Wuhan 430074,China) | 2003 | Acta Mechanica Solida Sinica2003,16,4: | 13 |
| 17 | In situ experiments on width and evolution characteristics of excavation damaged zone in deeply buried tunnels显示文摘The seven long tunnels of Jinping II hydropower station are deeply buried.The width and evolution characteristics of excavation damaged zone(EDZ) are the key problem to the design of tunnels excavation and supports.In order to study this problem,several specific experimental tunnels with different overburden and geometric sizes were excavated at this site.Digital borehole camera,sliding micrometer,cross-hole acoustic wave equipment and acoustic emission apparatus were adopted.This paper introduced the comprehensive in situ experimental methods through pre-installed facilities and pre-drilled boreholes.Typical properties of the surrounding rock mass,including cracks,deformation,elastic wave and micro fractures,were measured during the whole process of the tunnel excavation.The width and characteristics of formation and evolution of tunnels EDZ were analyzed under different construction methods involving of TBM and drilling and blasting,the test tunnels were excavated by full-face or two benches.The relationships between EDZ and tunnel geometry sizes,overburden and excavation method were described as well.The results will not only contribute a great deal to the analysis of rock mass behavior in deeply buried rock mass,but also provide direct data for support design and rockburst prediction. | LI ShaoJun 1,FENG XiaTing 1,LI ZhanHai 3,CHEN BingRui 1,JIANG Quan 1,WU ShiYong 2,HU Bin 2 &XU JinSong 2 1 State Key Laboratory of Geomechanics and Geotechinical Engineering,Institute of Rock and Soil Mechanics,Chinese Academy of Sciences,Wuhan 430071,China 2 Ertan Hydropower Development Company,Ltd.,Chengdu 610051,China 3 School of Resources and Civil Engineering,Northeastern University,Shenyang 110004,China | 2011 | Science China(Technological Sciences)2011,54,S1: | 13 |
| 18 | Microstructural variation of hardened cement-fly ash pastes leached by soft water显示文摘The microstructural variations of hardened cement-fly ash pastes leached by soft water were investigated by MIP, XRD, TG and SEM. The results show that the mass of hardened cement-fly ash paste reduces and its microstructure deteriorates partly after leaching of soft water. At the leaching duration of 180 days, the hardened paste containing fly ash deteriorated a little more serious than the plain cement paste, but the incorporation of fly ash in a proper ratio was helpful to defer the trend of deterioration of the hardened paste microstructure. The microstructural stability of hardened cement-fly ash paste wasn’t damaged severely during the 180 days leaching duration. | LI Xiang & YAN PeiYu* Department of Civil Engineering, Tsinghua University, Beijing 100084, China | 2010 | Science China(Technological Sciences)2010,53,11: | 12 |
| 19 | Inter-basin water transfer-supply model and risk analysis with consideration of rainfall forecast information显示文摘This paper develops a new inter-basin water transfer-supply and risk assessment model with consideration of rainfall forecast information. Firstly, based on the current state of reservoir and rainfall forecast information from the global forecast system (GFS), the actual diversion amount can be determined according to the inter-basin water transfer rules with the decision tree method; secondly, the reservoir supply operation system is used to distribute water resource of the inter-basin water transfer reservoir; finally, the integrated risk assessment model is built by selecting the reliability of water transfer, the reliability (water shortage risk), the resiliency and the vulnerability of water supply as risk analysis indexes. The case study shows that the inter-basin water transfer-supply model with rainfall forecast information considered can reduce the comprehensive risk and improve the utilization efficiency of water resource, as compared with conventional and optimal water distribution models. | XI ShuFeng1, WANG BenDe1, LIANG GuoHua1, LI XueSen2 & LOU LiLi3 1 School of Civil and Hydraulic Engineering, Dalian University of Technology, Dalian 116024, China 2 Management Bureau of Tanghe Reservoir, Liaoyang 111000, China 3 Institute of Dalian Water Science, Dalian 116013, China | 2010 | Science China(Technological Sciences)2010,53,12: | 12 |
| 20 | Boundary element-free method for elastodynamics显示文摘The moving least-square approximation is discussed first. Sometimes the method can form an ill-conditioned equation system, and thus the solution cannot be obtained correctly. A Hilbert space is presented on which an orthogonal function system mixed a weight function is defined. Next the improved moving least-square approximation is discussed in detail. The improved method has higher computational efficiency and precision than the old method, and cannot form an ill-conditioned equation system. A boundary element-free method (BEFM) for elastodynamics problems is presented by combining the boundary integral equation method for elastodynamics and the improved moving least-square approximation. The boundary element-free method is a meshless method of boundary integral equation and is a direct numerical method compared with others, in which the basic unknowns are the real solutions of the nodal variables and the boundary conditions can be applied easily. The boundary element-free method has a higher computational efficiency and precision. In addition, the numerical procedure of the boundary element-free method for elastodynamics problems is presented in this paper. Finally, some numerical examples are given. | CHENG Yumin1 & PENG Miaojuan2 1. Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200072, China 2. Department of Civil Engineering, Shanghai University, Shanghai 200072, China | 2005 | Science China(Physics,Mechanics & Astronomy)2005,48,6: | 12 |