Competitive adsorption isotherm data for two enantiomers of tryptophan, in which the stationary phase was silica-immobilized bovine serum albumin(BSA) and the mobile phase was a phosphate buffer,were measured by using...Competitive adsorption isotherm data for two enantiomers of tryptophan, in which the stationary phase was silica-immobilized bovine serum albumin(BSA) and the mobile phase was a phosphate buffer,were measured by using the inverse method.The competitive bi-Langmuir isotherm model(Fisher coefficient is 1769.07, R2=0.9997) and equilibrium-dispersive model were selected by comparison of the experimental results and the interaction mechanism.The corresponding parameters were obtained by simulating the chromatogram of racemic mixture at 2×10 -4 mol·L -1 and 10 -3 mol·L -1.The results showed good agreement between the isotherm determined by the inverse method and the adsorption data (Fisher coefficient is 119.32, R2=0.9973) which confirmed the validity of the model selected.展开更多
In terms of numerical method of Smoluchowski equation the behavior of fission process in diffusion model has been described and analyzed, including the reliance upon time, as well as the deformation parameters at seve...In terms of numerical method of Smoluchowski equation the behavior of fission process in diffusion model has been described and analyzed, including the reliance upon time, as well as the deformation parameters at several nuclear temperatures in this paper. The fission rates and the residual probabilities inside the saddle point are calculated for fissile nucleus n＋^238U reaction and un-fissile nucleus p＋^208Pb reaction. The results indicate that there really exists a transient fission process, which means that the pre-equillbrium fission should be taken into account for the fissile nucleus at the high temperature. Oppositely, the pre-equilibrlum fission could be neglected for the un-fissile nucleus. In the certain case the overshooting phenomenon of the fission rates will occur, which is mainly determined by the diffusive current at the saddle point. The higher the temperature is, the more obvious the overshooting phenomenon is. However, the emissions of the light particles accompanying the diffusion process may weaken or vanish the overshooting phenomenon.展开更多
The Intalox metal tower packing was used to simulate an industrial relevant extractive distillation column for purifying azeotropic multicomponent mixture.In order to explain the inconsistencies in the modeling of tra...The Intalox metal tower packing was used to simulate an industrial relevant extractive distillation column for purifying azeotropic multicomponent mixture.In order to explain the inconsistencies in the modeling of transfer process in nonideal multicomponent distillation column,a method was developed with equilibrium stage models(EQ)and non-equilibrium model(NEQ)incorporated with Maxwell-Stefan diffusion equations in the framework of AspenONE simulator.Dortmund Modified UNIFAC(UNIFAC-DMD)thermodynamic model was employed to estimate activity coefficients.In addition,to understand the reason for the diffusion against driving force and the different results by EQ and NEQ models,explicit investigations were made on diffusion coefficients, component Murphree efficiency and mass transfer coefficients.The results provide valuable information for basic design and applications associated with extractive distillation.展开更多
This paper is devoted to the analysis of the Cauchy problem for a system of PDEs arising in radiative hydrodynamics. This system, which comes from the so-called equilibrium diffusion regime, is a variant of the usual ...This paper is devoted to the analysis of the Cauchy problem for a system of PDEs arising in radiative hydrodynamics. This system, which comes from the so-called equilibrium diffusion regime, is a variant of the usual Euler equations, where the energy and pressure functionals are modified to take into account the effect of radiation and the energy balance containing a nonlinear diffusion term acting on the temperature. The problem is studied in the multi-dimensional framework. The authors identify the existence of a strictly convex entropy and a stability property of the system, and check that the Kawashima-Shizuta condition holds. Then, based on these structure properties, the wellposedness close to a constant state can be proved by using fine energy estimates. The asymptotic decay of the solutions are also investigated.展开更多
In this paper, an SIQS epidemic model with constant recruitment and standard inci- dence is investigated. Quarantine is taken into consideration on the basis of SIS model. The asymptotic stability of the equilibrium t...In this paper, an SIQS epidemic model with constant recruitment and standard inci- dence is investigated. Quarantine is taken into consideration on the basis of SIS model. The asymptotic stability of the equilibrium to a reaction^diffusion system with homo- geneous Neumann boundary conditions is considered. Sufficient conditions for the local and global asymptotic stability are given by linearization and the method of upper and lower solutions and its associated monotone iterations. The result shows that the disease-free equilibrium is globally asymptotically stable if the contact rate is small.展开更多
文摘Competitive adsorption isotherm data for two enantiomers of tryptophan, in which the stationary phase was silica-immobilized bovine serum albumin(BSA) and the mobile phase was a phosphate buffer,were measured by using the inverse method.The competitive bi-Langmuir isotherm model(Fisher coefficient is 1769.07, R2=0.9997) and equilibrium-dispersive model were selected by comparison of the experimental results and the interaction mechanism.The corresponding parameters were obtained by simulating the chromatogram of racemic mixture at 2×10 -4 mol·L -1 and 10 -3 mol·L -1.The results showed good agreement between the isotherm determined by the inverse method and the adsorption data (Fisher coefficient is 119.32, R2=0.9973) which confirmed the validity of the model selected.
基金The project supported by National Natural Science Foundation of China under Grant No. 10547005
文摘In terms of numerical method of Smoluchowski equation the behavior of fission process in diffusion model has been described and analyzed, including the reliance upon time, as well as the deformation parameters at several nuclear temperatures in this paper. The fission rates and the residual probabilities inside the saddle point are calculated for fissile nucleus n＋^238U reaction and un-fissile nucleus p＋^208Pb reaction. The results indicate that there really exists a transient fission process, which means that the pre-equillbrium fission should be taken into account for the fissile nucleus at the high temperature. Oppositely, the pre-equilibrlum fission could be neglected for the un-fissile nucleus. In the certain case the overshooting phenomenon of the fission rates will occur, which is mainly determined by the diffusive current at the saddle point. The higher the temperature is, the more obvious the overshooting phenomenon is. However, the emissions of the light particles accompanying the diffusion process may weaken or vanish the overshooting phenomenon.
基金Supported by the National Natural Science Foundation of China （20776118）, Science ＆ Technology Bureau of Xi＇an [CXY09019 （1）], Innovation Foundation for Graduated Student of Northwest University （08YJC21）, Shaanxi Research Center of Engineering Technology for Clean Coal Conversion （2008ZDGC-13）.
文摘The Intalox metal tower packing was used to simulate an industrial relevant extractive distillation column for purifying azeotropic multicomponent mixture.In order to explain the inconsistencies in the modeling of transfer process in nonideal multicomponent distillation column,a method was developed with equilibrium stage models(EQ)and non-equilibrium model(NEQ)incorporated with Maxwell-Stefan diffusion equations in the framework of AspenONE simulator.Dortmund Modified UNIFAC(UNIFAC-DMD)thermodynamic model was employed to estimate activity coefficients.In addition,to understand the reason for the diffusion against driving force and the different results by EQ and NEQ models,explicit investigations were made on diffusion coefficients, component Murphree efficiency and mass transfer coefficients.The results provide valuable information for basic design and applications associated with extractive distillation.
基金Project supported by the Fundamental Research Funds for the Central Universities (No. 2009B27514)the National Natural Science Foundation of China (No. 10871059)
文摘This paper is devoted to the analysis of the Cauchy problem for a system of PDEs arising in radiative hydrodynamics. This system, which comes from the so-called equilibrium diffusion regime, is a variant of the usual Euler equations, where the energy and pressure functionals are modified to take into account the effect of radiation and the energy balance containing a nonlinear diffusion term acting on the temperature. The problem is studied in the multi-dimensional framework. The authors identify the existence of a strictly convex entropy and a stability property of the system, and check that the Kawashima-Shizuta condition holds. Then, based on these structure properties, the wellposedness close to a constant state can be proved by using fine energy estimates. The asymptotic decay of the solutions are also investigated.
基金This work was financially supported by the Natural Science Foundation of China （11271236, 11401356） and the Natural Science Basic Research Plan in Shaanxi Province of China （No. 2015JM1008）.
文摘In this paper, an SIQS epidemic model with constant recruitment and standard inci- dence is investigated. Quarantine is taken into consideration on the basis of SIS model. The asymptotic stability of the equilibrium to a reaction^diffusion system with homo- geneous Neumann boundary conditions is considered. Sufficient conditions for the local and global asymptotic stability are given by linearization and the method of upper and lower solutions and its associated monotone iterations. The result shows that the disease-free equilibrium is globally asymptotically stable if the contact rate is small.
