By means of variable separation approach, quite a general excitation of the new (2 + 1)-dimensional long dispersive wave system: is derived. Some types of the usual localized excitations such as dromions, lumps, ring...By means of variable separation approach, quite a general excitation of the new (2 + 1)-dimensional long dispersive wave system: is derived. Some types of the usual localized excitations such as dromions, lumps, rings, and oscillating soliton excitations can be easily constructed by selecting the arbitrary functions appropriately. Besides these usual localized structures, some new localized excitations like fractal-dromion, fractal-lump, and multi-peakon excitations of this new system are found by selecting appropriate functions.展开更多
Using the generalized conditional symmetry approach, we obtain a number of new generalized (1+1)-dimensional nonlinear wave equations that admit derivative-dependent functional separable solutions.
The multi-linear variable separation approach method is very useful to solve (2+1)-dimensional integrable systems. In this letter, we extend this method to solve (1+1)-dimensional Boiti system, (2+1)-dimensional Burge...The multi-linear variable separation approach method is very useful to solve (2+1)-dimensional integrable systems. In this letter, we extend this method to solve (1+1)-dimensional Boiti system, (2+1)-dimensional Burgers system, (2+1)-dimensional breaking soliton system, and (2+1)-dimensional Maccari system. Some new exact solutions are obtained and the universal formula obtained from many (2+1)-dimensional systems is extended or modified.展开更多
Porous poly(vinylidene fluoride)(PVDF)/poly(methyl methacrylate)(PMMA) blend five-bore hollow fiber membranes are prepared by wet phase inversion methods.In spinning these PVDF hollow fibers, N,N-dimethylacetamide(DMA...Porous poly(vinylidene fluoride)(PVDF)/poly(methyl methacrylate)(PMMA) blend five-bore hollow fiber membranes are prepared by wet phase inversion methods.In spinning these PVDF hollow fibers, N,N-dimethylacetamide(DMAc) and polyvinyl pyrrolidone(PVP) are used as the solvent and the non-solvent additive,respectively.The external coagulant uses water.The internal coagulants use water and DMAc-water solutions.The membranes are characterized in terms of water flux and molecular weight cut-off for the wet membranes.The cross-sectional structures are examined by scanning electron microscopy(SEM).The effects of polymer concentration and the internal coagulant on the permeation properties and membrane structures are examined keeping the bore liquid flow and air-gap constants.Relative high flux,rejection and strengh PVDF five-bore hollow fiber membranes could be prepared from the polymer concentration in dope solution at 17%of mass fraction,the air gap distance of 14 cm,and using 10%of mass fraction of DMAc solution as the internal coagulant at 13 mL/min of flow.展开更多
文摘By means of variable separation approach, quite a general excitation of the new (2 + 1)-dimensional long dispersive wave system: is derived. Some types of the usual localized excitations such as dromions, lumps, rings, and oscillating soliton excitations can be easily constructed by selecting the arbitrary functions appropriately. Besides these usual localized structures, some new localized excitations like fractal-dromion, fractal-lump, and multi-peakon excitations of this new system are found by selecting appropriate functions.
基金The project supported by the National Outstanding Youth Foundation of China (No.19925522)+2 种基金the Research Fund for the Doctoral Program of Higher Education of China (Grant.No.2000024832)National Natural Science Foundation of China (No.90203001)
文摘Using the generalized conditional symmetry approach, we obtain a number of new generalized (1+1)-dimensional nonlinear wave equations that admit derivative-dependent functional separable solutions.
文摘The multi-linear variable separation approach method is very useful to solve (2+1)-dimensional integrable systems. In this letter, we extend this method to solve (1+1)-dimensional Boiti system, (2+1)-dimensional Burgers system, (2+1)-dimensional breaking soliton system, and (2+1)-dimensional Maccari system. Some new exact solutions are obtained and the universal formula obtained from many (2+1)-dimensional systems is extended or modified.
基金the China Postdoctoral Science Foundation (No.20110490645)the Science Foundation of Shanghai(No.11ZR1400800)
文摘Porous poly(vinylidene fluoride)(PVDF)/poly(methyl methacrylate)(PMMA) blend five-bore hollow fiber membranes are prepared by wet phase inversion methods.In spinning these PVDF hollow fibers, N,N-dimethylacetamide(DMAc) and polyvinyl pyrrolidone(PVP) are used as the solvent and the non-solvent additive,respectively.The external coagulant uses water.The internal coagulants use water and DMAc-water solutions.The membranes are characterized in terms of water flux and molecular weight cut-off for the wet membranes.The cross-sectional structures are examined by scanning electron microscopy(SEM).The effects of polymer concentration and the internal coagulant on the permeation properties and membrane structures are examined keeping the bore liquid flow and air-gap constants.Relative high flux,rejection and strengh PVDF five-bore hollow fiber membranes could be prepared from the polymer concentration in dope solution at 17%of mass fraction,the air gap distance of 14 cm,and using 10%of mass fraction of DMAc solution as the internal coagulant at 13 mL/min of flow.
