Seeking exact analytical solutions of nonlinear evolution equations is of fundamental importance in mathematlcal physics. In this paper, based on a constructive algorithm and symbolic computation, abundant new exact s...Seeking exact analytical solutions of nonlinear evolution equations is of fundamental importance in mathematlcal physics. In this paper, based on a constructive algorithm and symbolic computation, abundant new exact solutions of the （2＋1）-dimensional dispersive long wave equations are obtained, among which there are soliton-like solutions, mult-soliton-like solutions and formal periodic solutions, etc. Certain special solutions are considered and some interesting localized structures are revealed.展开更多
A new （2＋1）-dimensional KdV equation is constructed by using Lax pair generating technique. Exact solutions of the new equation are studied by means of the singular manifold method. Bgcklund transformation in terms...A new （2＋1）-dimensional KdV equation is constructed by using Lax pair generating technique. Exact solutions of the new equation are studied by means of the singular manifold method. Bgcklund transformation in terms of the singular manifold is obtained. And localized structures are also investigated.展开更多
Deep coal seam mining floor strata water bursting is a complicate nonlinear system, whose factors are coupling and influencing themselves. It built the analytic structure model for deep coal seam mining floor strata w...Deep coal seam mining floor strata water bursting is a complicate nonlinear system, whose factors are coupling and influencing themselves. It built the analytic structure model for deep coal seam mining floor strata water bursting, the judgment matrix was found by the expert scoring method, the contribution weights of the influenced factors were given out by the equation analytic process. The thirteen controlling factors and five main controlling factors were put award by analyzing weights, so the result was basically conform to the field practice. The expert scoring method and analytic process can convert the objective fact to the subjective cognition, so it is a method that can turn the qualitative into the quantitative. This can be relative objectively and precisely to study the question of many factors and grey box.展开更多
Effect of configuration （structure of electrode, interelectrode gap, positions of inlet and outlet, volume of the cell and additional nets） on mass transfer characteristic of a filter-press type electrochemical cell...Effect of configuration （structure of electrode, interelectrode gap, positions of inlet and outlet, volume of the cell and additional nets） on mass transfer characteristic of a filter-press type electrochemical cell has been studied. The mass transfer coefficients on the electrodes were obtained by using the well-known technique based on the determination of limiting diffusion current. It is found that mass transfer coefficients with mesh electrode are greater than that of with plate electrode. Mass transfer coefficient is decreased with interelectrode gap. While interelectrode gap achieved a certain value （7 ram）, mass transfer coefficient is steady, no more declining. Mass transfer characteristic for different positions of inlet and outlet are different and dimensionless number groups correlated equations are obtained by experiment. Mass transfer characteristic is the best when inlet located on the top and outlet on the bottom of the cell respectively. While magnified the volume of the cell to eight times, mass transfer characteristic changes little. Mass transfer characteristic without nets is lower than that of with additional nets in the exit region, but higher than that of with additional nets in the entry region.展开更多
This paper aims at presenting the guidelines for an urban regeneration strategy in Lisbon, having in account the principles of urbanity, density, livability and social and territorial cohesion. The case study will be ...This paper aims at presenting the guidelines for an urban regeneration strategy in Lisbon, having in account the principles of urbanity, density, livability and social and territorial cohesion. The case study will be Avenidas Novas district, in Lisbon, Portugal, as it is a paradigmatic example of a central area which coexists with dynamism and decadence. The development model for Avenidas Novas was inspired on French boulevards and was planned to be the modem face of a medium to high social class population, as it was until 1940s. Today, as a consequence of further developments which corrupted the first principles and concept, its urban fabric is becoming less coherent and adequate to the needs of the population who works and lives there. From an analysis to the various components of the urban fabric, the paper will identify the major problems that are happening on the site, related to accessibility, mobility and functional diversity. Once understanding the impacts of an unsustainable territory management and urban design, the goal is to develop the principles for a creative urban regeneration strategy for Avenidas Novas district. The study will be based on the theoretical issues of the compact city and walkable distances in order to develop quantifying parameters of urban quality and to promote human scale public spaces and territorial cohesion on an urban environment.展开更多
基金The project supported by the China Postdoctoral Science Foundation under Grant No. 2004036086, K.C. Wong Education Foundation, Hong Kong, and partially supported by the State Key Basic Research Program of China under Grant No. 2004CB318000 . The authors are grateful to professor Gao Xiao-Shan for his enthusiastic guidance and help.
文摘Seeking exact analytical solutions of nonlinear evolution equations is of fundamental importance in mathematlcal physics. In this paper, based on a constructive algorithm and symbolic computation, abundant new exact solutions of the （2＋1）-dimensional dispersive long wave equations are obtained, among which there are soliton-like solutions, mult-soliton-like solutions and formal periodic solutions, etc. Certain special solutions are considered and some interesting localized structures are revealed.
基金Supported by Research Fund for the Doctoral Program of Higher Education of China under Grant No.20070486094
文摘A new （2＋1）-dimensional KdV equation is constructed by using Lax pair generating technique. Exact solutions of the new equation are studied by means of the singular manifold method. Bgcklund transformation in terms of the singular manifold is obtained. And localized structures are also investigated.
文摘Deep coal seam mining floor strata water bursting is a complicate nonlinear system, whose factors are coupling and influencing themselves. It built the analytic structure model for deep coal seam mining floor strata water bursting, the judgment matrix was found by the expert scoring method, the contribution weights of the influenced factors were given out by the equation analytic process. The thirteen controlling factors and five main controlling factors were put award by analyzing weights, so the result was basically conform to the field practice. The expert scoring method and analytic process can convert the objective fact to the subjective cognition, so it is a method that can turn the qualitative into the quantitative. This can be relative objectively and precisely to study the question of many factors and grey box.
基金Supported by the National Natural Science Foundation of China （20573045, 20843001）, the ＂Tenth Five-Year＂ National Key Scientific and Technological Project （2004BA313B-17） and the National High Technology Research and Development Pro gram of China （2006AA06Z321）.
文摘Effect of configuration （structure of electrode, interelectrode gap, positions of inlet and outlet, volume of the cell and additional nets） on mass transfer characteristic of a filter-press type electrochemical cell has been studied. The mass transfer coefficients on the electrodes were obtained by using the well-known technique based on the determination of limiting diffusion current. It is found that mass transfer coefficients with mesh electrode are greater than that of with plate electrode. Mass transfer coefficient is decreased with interelectrode gap. While interelectrode gap achieved a certain value （7 ram）, mass transfer coefficient is steady, no more declining. Mass transfer characteristic for different positions of inlet and outlet are different and dimensionless number groups correlated equations are obtained by experiment. Mass transfer characteristic is the best when inlet located on the top and outlet on the bottom of the cell respectively. While magnified the volume of the cell to eight times, mass transfer characteristic changes little. Mass transfer characteristic without nets is lower than that of with additional nets in the exit region, but higher than that of with additional nets in the entry region.
文摘This paper aims at presenting the guidelines for an urban regeneration strategy in Lisbon, having in account the principles of urbanity, density, livability and social and territorial cohesion. The case study will be Avenidas Novas district, in Lisbon, Portugal, as it is a paradigmatic example of a central area which coexists with dynamism and decadence. The development model for Avenidas Novas was inspired on French boulevards and was planned to be the modem face of a medium to high social class population, as it was until 1940s. Today, as a consequence of further developments which corrupted the first principles and concept, its urban fabric is becoming less coherent and adequate to the needs of the population who works and lives there. From an analysis to the various components of the urban fabric, the paper will identify the major problems that are happening on the site, related to accessibility, mobility and functional diversity. Once understanding the impacts of an unsustainable territory management and urban design, the goal is to develop the principles for a creative urban regeneration strategy for Avenidas Novas district. The study will be based on the theoretical issues of the compact city and walkable distances in order to develop quantifying parameters of urban quality and to promote human scale public spaces and territorial cohesion on an urban environment.
