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DUAL RECIPROCITY HYBRID BOUNDARY NODE METHOD FOR THREE-DIMENSIONAL ELASTICITY WITH BODY FORCE

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Acta Mechanica Solida Sinica 2008年第3期21卷 267-277页

作者： fei Yan Yuanhan Wang Yu Miao fei tan School of Civil Engineering and Mechanics Huazhong University of Science and Technology Wuhan 430074 China

Combining Dual Reciprocity Method （DRM） with Hybrid Boundary Node Method （HBNM）, the Dual Reciprocity Hybrid Boundary Node Method （DRHBNM） is developed for three-dimensional linear elasticity problems with body force. This method can be used to solve the elasticity problems with body force without domain integral, which is inevitable by HBNM. To demonstrate the versatility and the fast convergence of this method, some numerical examples of 3-D elasticity problems with body forces are examined. The computational results show that the present method is effective and can be widely applied in solving practical engineering problems.

关键词： hybrid boundary node method dual reciprocity method body force radial basis function

Improvement of contact calculation in spherical discontinuous deformation analysis

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Science China(Technological Sciences) 2017年第5期60卷 765-771页

作者： WANG Long JIAO YuYong HUANG GangHai ZHENG fei ZHAO ZhiYe tan fei State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences Department of Civil and Environmental Engineering University of California School of Civil and Environmental Engineering Nanyang Technological University

Discontinuous deformation analysis （DDA） method is a newly developed discrete element method which employs the implicit time-integration scheme to solve the governing equations and the open-close iteration （OCI） method to deal with contact prob- lem, its computational efficiency is relatively low. However, spherical element based discontinuous deformation analysis （SDDA）, which uses very simple contact type like point-to-point contact, has higher calculation speed. In the framework of SDDA, this paper presents a very simple contact calculation approach by removing the OCI scheme and by adopting the maximal displacement increment （MDI）. Through some verification examples, it is proved that the proposed method is correct and effective, and a higher computational efficiency is obtained.

关键词： 3D-DDA spherical element open-close iteration calculation efficiency

The BEM based on conformal Duffy-distance transformation for three-dimensional elasticity problems

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Science China(Technological Sciences) 2020年第12期63卷 2575-2583页

作者： tan fei LIANG JiaWei JIAO YuYong ZHU Shuai LV JiaHe Faculty of Engineering China University of GeosciencesWuhan 430074China

Here,we describe the robust and efficient application of the conventional 3D BEM in solving elasticity problems. We have focused on the precise computation of weakly singular integrals. The conformal Duffy-distance transformation was employed to alleviate near singularities caused from two aspects:(1) the large aspect ratio of elements,i.e.,element shape distortions;and(2)the closeness of element boundaries to field points,i.e.,ill-shaped patches. Then,the rigid body motion method was employed to evaluate strongly singular integrals. Numerical solutions of 3D elastostatic problems demonstrated the high accuracy of the proposed method with coarse meshes and high convergence rates with mesh refinement. Compared with the Duffy transformation and original polar coordinate transformations,the proposed method is insensitive to element shapes.

关键词： singular integrals boundary element method elasticity problems conformal transformation Duffy transformation distance transformation

Numerical Simulation and Analysis of Migration Law of Gas Mixture Using Carbon Dioxide as Cushion Gas in Underground Gas Storage Reservoir

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Journal of Harbin Institute of Technology(New Series) 2014年第3期21卷 121-128页

作者： Chuan-Kai Niu Yu-fei tan School of Municipal & Environment Engineering Harbin Institute of Technology

One of the major technical challenges in using carbon dioxide( CO2) as part of the cushion gas of the underground gas storage reservoir( UGSR) is the mixture of CO2and natural gas. To decrease the mixing extent and manage the migration of the mixed zone,an understanding of the mechanism of CO2and natural gas mixing and the diffusion of the mixed gas in aquifer is necessary. In this paper,a numerical model based on the three dimensional gas-water two-phase flow theory and gas diffusion theory is developed to understand this mechanism. This model is validated by the actual operational data in Dazhangtuo UGSR in Tianjin City,*** the validated model,the mixed characteristic of CO2and natural gas and the migration mechanism of the mixed zone in an underground porous reservoir is further studied. Particularly,the impacts of the following factors on the migration mechanism are studied: the ratio of CO2injection,the reservoir porosity and the initial operating pressure. Based on the results,the optimal CO2injection ratio and an optimal control strategy to manage the migration of the mixed zone are obtained. These results provide technical guides for using CO2as cushion gas for UGSR in real projects.

关键词： underground gas storage reservoir(UGSR) cushion gas carbon dioxide mixed zone porous media

Three-dimensional numerical manifold method for heat conduction problems with a simplex integral on the boundary

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Science China(Technological Sciences) 2024年第4期67卷 1007-1022页

作者： TONG DeFu YI XiongWei tan fei JIAO YuYong LIANG JiaWei Faculty of Engineering China University of GeoscienceWuhan 430074China Department of Civil Engineering Monash UniversityMelbourne VIC 3800Australia Badong National Observation and Research Station of Geohazards China University of GeoscienceWuhan 430074China

The three-dimensional numerical manifold method(3D-NMM),which is based on the derivation of Galerkin's variation,is a powerful calculation tool that uses two cover *** 3D-NMM can be used to handle continue-discontinue problems and extend to THM *** this study,we extended the 3D-NMM to simulate both steady-state and transient heat conduction *** modelling was carried out using the raster methods(RSM).For the system equation,a variational method was employed to drive the discrete equations,and the crucial boundary conditions were solved using the penalty *** solve the boundary integral problem,the face integral of scalar fields and two-dimensional simplex integration were used to accurately describe the integral on polygonal *** numerical examples were used to verify the results of 3D steady-state and transient heat-conduction *** numerical results indicated that the 3D-NMM is effective for handling 3D both steadystate and transient heat conduction problems with high solution accuracy.

关键词： three-dimensional numerical manifold method transient analysis heat conduction problem Galerkin variation simplex integration

Parallelization of spherical discontinuous deformation analysis(SDDA) for geotechnical problems based on cloud computing environment

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Science China(Technological Sciences) 2021年第9期64卷 1971-1980页

作者： JIAO Yu-Yong WU ZeYang ZHENG fei ZHAO Qiang WANG Long HUANG Gang-Hai tan fei Faculty of Engineering China University of GeosciencesWuhan 430074China Shanghai Construction No.4(Group)Co. Ltd.Shanghai 201103China Economic and Technology Research Institute State Grid Shandong Electric Power CompanyJinan 250013China School of Civil Engineering Central South UniversityChangsha 410083China

The computational efficiency of the traditional serial spherical discontinuous deformation analysis(SDDA) program has limited its application in geotechnical engineering problems that need a large number of spheres. The cloud computing technology is used to parallel the SDDA program for the first time in this research. The most computationally intensive portions of the SDDA program, i.e., contact detection and matrix solution, are parallelized with proposed algorithms. The accuracy of the cloud-based parallel SDDA program(CB-PSDDA) is verified first. Further efficiency tests show that significant speedup can be obtained with an 8-server configuration and the computing scale can be up to several tens of thousands of particles. The cloud-based parallelized SDDA program increases its potential in applications of deformation and failure analysis of large-scale and realistic geotechnical engineering problems.

关键词： spherical discontinuous deformation analysis(SDDA) distributed computing cloud computing

Genetic Mechanism of Water-Rich Landslide Considering Antecedent Rainfalls:A Case Study of Pingyikou Landslide in Three Gorges Reservoir Area

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Journal of Earth Science 2023年第6期34卷 1878-1891页

作者： Defu Tong Aijun Su fei tan Jiandong tang Xiongwei Yi Faculty of Engineering China University of GeosciencesWuhan 430074China Badong National Observation and Research Station of Geohazards China University of GeosciencesWuhan 430074China China Construction Southwest Survey Design and Research Institute Co.Ltd.Chengdu 610052China

Water-rich slope,which could easily fail after prolonged or heavy rain,is very sensitive to *** Landslide is a typical water-rich slope located in the Three Gorges Reservoir area of *** was unstable because of the continuous rainfall that occurred from September to October *** understand the deformation process and genetic mechanism of the landslide,the geomorphological features,geological characteristics,hydrological conditions,and rainfall characteristics were systematically studied by a detailed field investigation of the slope and monitoring of rainfall,water level,and *** addition,the influence of different initial conditions on the stability of the slope was also studied through numerical simulation using measured rainfall data on the basis of which,the effect of antecedent rainfall on slope stability was studied by unsaturated seepage analysis *** results show that the deformation of slope is strongly correlated with the rainfall and groundwater level,and this landslide is a typical rainfall-induced *** the analysis of genetic mechanism of the same type of landslide,a maximum initial pore water pressure of -25 kPa as the initial condition is *** the antecedent rainfall has a greater effect on the stability of the slope,more than 10 days of antecedent rainfall should be considered when designing and controling the slope.

关键词： slope stability landslides unsaturated seepage antecedent rainfall disasters

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Lentiviral-mediated vascular endothelial growth factor 165 gene transfer into neural stem cells promotes proliferation

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Neural Regeneration Research 2011年第19期6卷 1457-1461页

作者： Shanshan Zhang Xiangrong Zheng fei Yin Jielu tan Yujia Yang Department of Pediatrics Xiangya Hospital Central South University Changsha 410008 Hunan Province China

We constructed a lentiviral vector carrying vascular endothelial growth factor 165, which was used to transfect neural stem cells. The transfection rate was approximately 50%, as determined by flow cytometry. Vascular... 详细信息

关键词： vascular endothelial growth factor 165 gene therapy lentivirus neural stem cells transfection

Synthesis, Crystal Structure and Characterization of a One-dimensional Supramolecular Rare Earth Complex of N-(6-(4-Methylpyridinyl))ketoacetamide

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Chinese Journal of Structural Chemistry 2007年第8期26卷 877-882页

作者： XU Li tanG Kuan-Zhen MA Yu-fei tanG Yu tan Min-Yu State Key Laboratory of Applied Organic Chemistry College of Chemistry and Chemical Engineering Lanzhou University Lanzhou 730000 China

A one-dimensional （1D） supramolecular rare earth complex [Nd（NO3）2L2-（C3H6O）][NdL（NO3）4]} （L=N-（6-（4-methylpyridinyl））ketoacetamide） has been prepared and characterized by elemental analysis, IR and electronic spectroscopy, and single-crystal X-ray diffraction. The crystal crystallizes in the triclinic system, space group P1^- with a=0.9146（6）, b=1.2581（8）, c=2.2316（14） nm, α=99.352（10）,β=97.209（9）, γ=103.935（9）°, V=2.422（3） nm3, Dc=1.776 g/cm^3, C33H42N12Nd2O25, Mr=1295.27, Z=2, F（000）=1288, μ=2.217 mm-1, R=0.0508and wR=0.1046 for 5173 observed reflections （I 〉 2σ（I））. In the structure of the title complex,one-dimensional supramolecular double-chains are formed by intermolecular hydrogen bonding interactions.

关键词： crystal structure rare earth nitrate β-diketone complex supramolecular network