On the basis of summarizing design methods of ecological urban park,it was proposed that preparatory control work should be enhanced,reasonable zoning of use functions and spatial structures established,overall consid...On the basis of summarizing design methods of ecological urban park,it was proposed that preparatory control work should be enhanced,reasonable zoning of use functions and spatial structures established,overall consideration given to traffi c system and vertical design,and landscaping system created based on ecological view. In addition,it was also signifi cant for designers and management departments taking proper planning and designs to create new urban open spaces,improve supporting facilities,enhance public participation mechanism,and keep pace with the sustainable development of the city.展开更多
Urban-rural transformation and rural development are issues at the forefront of research on the topic of the urban-rural relationship in the field of geography, as well as important practical problems facing China＇s ...Urban-rural transformation and rural development are issues at the forefront of research on the topic of the urban-rural relationship in the field of geography, as well as important practical problems facing China＇s new urbanization and overall planning of urban and rural development. The Center for Regional Agricultural and Rural Development, part of the Institute of Geographic Sciences and Natural Resources Research under the Chinese Academy of Sciences, was established in 2005. The Center has laid solid foundations for integrating research in the areas of agricultural geography and rural development in China over the past decade. The paper aims to review the major achievements in rural geographical research in China during the past decade, analyze innovative developments in relevant theories and methods, and suggest prospects and countermeasures for promoting comprehensive studies of urban-rural transformation and rural geography. The research shows that innovative achievements have been made in rural geography studies of China in the past decade as major national policy development, outputs of result and decision making support; new breakthroughs have been achieved in such major research projects as geographical integrated theory, land remediation projects and technology demonstration projects, new urbanization and urban-rural integration; significant progress has been made in actively expanding the frontiers of rural geography and pushing forward theoretical innovations in land and resource projects; and, with China＇s development goals of building a moderately prosperous society in all respects and achieving modernization in mind, future innovative developments in agricultural and rural geography should aim to make research more strategic, systematic, scientific and security-oriented, with attention given to promoting systematic scientific research on international cooperation and global rural geography.展开更多
This paper considers two dimensional systems which have purely imaginary eigenvalues.In order to obtain more propositions of invariant curves,the authors transform the real systems into complex differential systems by...This paper considers two dimensional systems which have purely imaginary eigenvalues.In order to obtain more propositions of invariant curves,the authors transform the real systems into complex differential systems by using a suitable linear transformation.The authors also propose an algorithm to compute exponential factors.An improved method of constructing integrating factor by using all invariant curves is presented and can be used in determining the type of the equilibrium points.展开更多
This paper constructs a strongly-consistent explicit finite difference scheme for 3D constant viscosity incompressible Navier-Stokes equations by using of symbolic algebraic computation.The difference scheme is space ...This paper constructs a strongly-consistent explicit finite difference scheme for 3D constant viscosity incompressible Navier-Stokes equations by using of symbolic algebraic computation.The difference scheme is space second order accurate and temporal first order accurate. It is proved that difference Grobner basis algorithm is correct. By using of difference Grobner basis computation method, an element in Gr?bner basis of difference scheme for momentum equations is a difference scheme for pressure Poisson equation. The authors find that the truncation errors expressions of difference scheme is consistent with continuous errors functions about modified version of above difference equation. The authors prove that, for strongly consistent difference scheme, each element in the difference Grobner basis of such difference scheme always approximates a differential equation which vanishes on the analytic solutions of Navier-Stokes equations. To prove the strongly-consistency of this difference scheme, the differential Thomas decomposition theorem for nonlinear differential equations and difference Grobner basis theorems for difference equations are applied. Numerical test certifies that strongly-consistent difference scheme is effective.展开更多
基金Supported by Youth Sci-Tech Development Foundation of Jilin Jianzhu University,"Design Method of Urban Ecological Park"(J20091059)
文摘On the basis of summarizing design methods of ecological urban park,it was proposed that preparatory control work should be enhanced,reasonable zoning of use functions and spatial structures established,overall consideration given to traffi c system and vertical design,and landscaping system created based on ecological view. In addition,it was also signifi cant for designers and management departments taking proper planning and designs to create new urban open spaces,improve supporting facilities,enhance public participation mechanism,and keep pace with the sustainable development of the city.
基金National Natural Science Foundation of China,No.41130748,No.41471143
文摘Urban-rural transformation and rural development are issues at the forefront of research on the topic of the urban-rural relationship in the field of geography, as well as important practical problems facing China＇s new urbanization and overall planning of urban and rural development. The Center for Regional Agricultural and Rural Development, part of the Institute of Geographic Sciences and Natural Resources Research under the Chinese Academy of Sciences, was established in 2005. The Center has laid solid foundations for integrating research in the areas of agricultural geography and rural development in China over the past decade. The paper aims to review the major achievements in rural geographical research in China during the past decade, analyze innovative developments in relevant theories and methods, and suggest prospects and countermeasures for promoting comprehensive studies of urban-rural transformation and rural geography. The research shows that innovative achievements have been made in rural geography studies of China in the past decade as major national policy development, outputs of result and decision making support; new breakthroughs have been achieved in such major research projects as geographical integrated theory, land remediation projects and technology demonstration projects, new urbanization and urban-rural integration; significant progress has been made in actively expanding the frontiers of rural geography and pushing forward theoretical innovations in land and resource projects; and, with China＇s development goals of building a moderately prosperous society in all respects and achieving modernization in mind, future innovative developments in agricultural and rural geography should aim to make research more strategic, systematic, scientific and security-oriented, with attention given to promoting systematic scientific research on international cooperation and global rural geography.
基金supported by the National Natural Science Foundation of China under Grant No.11271363
文摘This paper considers two dimensional systems which have purely imaginary eigenvalues.In order to obtain more propositions of invariant curves,the authors transform the real systems into complex differential systems by using a suitable linear transformation.The authors also propose an algorithm to compute exponential factors.An improved method of constructing integrating factor by using all invariant curves is presented and can be used in determining the type of the equilibrium points.
基金supported by the National Natural Science Foundation of China under Grant No.11271363。
文摘This paper constructs a strongly-consistent explicit finite difference scheme for 3D constant viscosity incompressible Navier-Stokes equations by using of symbolic algebraic computation.The difference scheme is space second order accurate and temporal first order accurate. It is proved that difference Grobner basis algorithm is correct. By using of difference Grobner basis computation method, an element in Gr?bner basis of difference scheme for momentum equations is a difference scheme for pressure Poisson equation. The authors find that the truncation errors expressions of difference scheme is consistent with continuous errors functions about modified version of above difference equation. The authors prove that, for strongly consistent difference scheme, each element in the difference Grobner basis of such difference scheme always approximates a differential equation which vanishes on the analytic solutions of Navier-Stokes equations. To prove the strongly-consistency of this difference scheme, the differential Thomas decomposition theorem for nonlinear differential equations and difference Grobner basis theorems for difference equations are applied. Numerical test certifies that strongly-consistent difference scheme is effective.
