A modified form of 2CLJDQP potential model is proposed to calculate the second virial coefficients of two-center Lennard-Jones molecules. In the presented potential model, the potential parameters σ and ε are consid...A modified form of 2CLJDQP potential model is proposed to calculate the second virial coefficients of two-center Lennard-Jones molecules. In the presented potential model, the potential parameters σ and ε are considered as the temperature-dependent parameters in the form of hyperbolical temperature function based on the theory of temperaturedependent potential parameters. With this modified model, the second virial coefficients of some homonuclear molecules（such as O2, Cl2, CH3CH3, and CF3CF3） and heteronuclear molecules（such as CO, NO, CH3 F, CH3 Cl, CH3CF3,CH3CHF2, and CF3CH2F） are calculated. Then the Lorentz–Berthelot mixing rule is modified with a temperaturedependent expression, and the second virial coefficients of the heteronuclear molecules（such as CH3 F, CH3 Cl, and CH3CF3） are calculated. Moreover, CO2 and N2O are also studied with the modified 3CLJDQP model. The calculated results from the modified 2CLJDQP model accord better with the experimental data than those from the original model.It is shown that the presented model improves the positive deviation in low temperature range and negative deviation in high temperature range. So the modified 2CLJDQP potential model with the temperature-dependent parameters can be employed satisfactorily in large temperature range.展开更多
In this paper a new relation between the second virial coefficients A_2, (?)_w and (dV_(es)/dC)_c→0=K_s was derived from proposed model theory of concentration effects in GPC for mono-and poly-dispersed polymers. Bas...In this paper a new relation between the second virial coefficients A_2, (?)_w and (dV_(es)/dC)_c→0=K_s was derived from proposed model theory of concentration effects in GPC for mono-and poly-dispersed polymers. Based on this relation a new method for determination of second vifial coefficients from the combination of (dV_(es)/dC)_c→0=K_3, (?)_w and K_H measurements was proposed.The values of A_2 for mono-and poly-dispersed polystyrenes with molecular weight range from 10~4 to 10~6 in good and theta solvents were determined by proposed method. Results show that their values of A_2 are in agreement with those obtained by light scattering.展开更多
In this paper we consider the class ∑^＊（p,α,β,k,c） consisting of analytic functions with negativecoefficients and fixed second coefficient. The object of the present paper is to give coefficient estimates, conve...In this paper we consider the class ∑^＊（p,α,β,k,c） consisting of analytic functions with negativecoefficients and fixed second coefficient. The object of the present paper is to give coefficient estimates, convex linear combinations, some distortion theorems and radii of starlikeness and convexity for f（z） in the class ∑^＊（p,α,β,k,c） .展开更多
In this paper, we investigate some argument properties for analytic functions with fixed second coefficient and positive real part. And we apply the argument properties to the functions that are analytic and normalize...In this paper, we investigate some argument properties for analytic functions with fixed second coefficient and positive real part. And we apply the argument properties to the functions that are analytic and normalized. In particular, the order of strongly starlikeness of strongly convex functions with fixed second coefficients is given.展开更多
Refrigeration coefficient, ε, is usually calculated by using the First Law of Thermodynamics. In this paper, a new derivation process is introduced through the combination of the Second Law of Thermodynamics with the...Refrigeration coefficient, ε, is usually calculated by using the First Law of Thermodynamics. In this paper, a new derivation process is introduced through the combination of the Second Law of Thermodynamics with the First Law of Thermodynamics. As a result, two new calculation equations for refrigeration coefficient are proposed. One equation is equivalent to the common method, but its form is a little complicated for real calculation. Another equation is the further simplification, and can be used to calculate the refrigeration coefficient instead of common method with a oermit error.展开更多
A two-scale second-order moment two-phase turbulence model accounting for inter-particle collision is developed, based on the concept of particle large-scale fluctuation due to turbulence and particle small-scale fluc...A two-scale second-order moment two-phase turbulence model accounting for inter-particle collision is developed, based on the concept of particle large-scale fluctuation due to turbulence and particle small-scale fluctuation due to collision. The proposed model is used to simulate gas-particle downer reactor flows. The computational results of both particle volume fraction and mean velocity are in agreement with the experimental results. After analyzing effects of empirical coefficient on prediction results, we can come to a conclusion that, inside the limit range of empirical coefficient, the predictions do not reveal a large sensitivity to the empirical coefficient in the downer reactor, but a relatively great change of the constants has important effect on the prediction.展开更多
We study the hyperbolic–parabolic equations with rapidly oscillating coefficients. The formal second-order two-scale asymptotic expansion solutions are constructed by the multiscale asymptotic analysis. In addition, ...We study the hyperbolic–parabolic equations with rapidly oscillating coefficients. The formal second-order two-scale asymptotic expansion solutions are constructed by the multiscale asymptotic analysis. In addition, we theoretically explain the importance of the second-order two-scale solution by the error analysis in the pointwise sense. The associated explicit convergence rates are also obtained. Then a second-order two-scale numerical method based on the Newmark scheme is presented to solve the equations. Finally, some numerical examples are used to verify the effectiveness and efficiency of the multiscale numerical algorithm we proposed.展开更多
According to the existing concrete core samples obtained in site, chloride concentration and porosity of existing normal hydraulic concrete were measured, and chloride diffusivity in existing hydraulic concrete was st...According to the existing concrete core samples obtained in site, chloride concentration and porosity of existing normal hydraulic concrete were measured, and chloride diffusivity in existing hydraulic concrete was studied. By Fick’s second law, the chloride diffusion coefficients in the steady diffusion area were calculated. The chloride diffusion of different mix proportion concrete was tested, and chloride diffusion coefficients and porosities of freshly concrete were measured, moreover, the relationship between diffusion coefficient and porosity was analyzed. The results show that the varying law of chloride diffusion coefficient with exposure time of existing concrete can be predicted in a better way by Fick’s second law and water-cement ratios or porosity of concrete and chloride concentration in existing concrete.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.51106129)the Fundamental Research Funds for the Central University,China(Grant No.XJTU-HRT-002)
文摘A modified form of 2CLJDQP potential model is proposed to calculate the second virial coefficients of two-center Lennard-Jones molecules. In the presented potential model, the potential parameters σ and ε are considered as the temperature-dependent parameters in the form of hyperbolical temperature function based on the theory of temperaturedependent potential parameters. With this modified model, the second virial coefficients of some homonuclear molecules（such as O2, Cl2, CH3CH3, and CF3CF3） and heteronuclear molecules（such as CO, NO, CH3 F, CH3 Cl, CH3CF3,CH3CHF2, and CF3CH2F） are calculated. Then the Lorentz–Berthelot mixing rule is modified with a temperaturedependent expression, and the second virial coefficients of the heteronuclear molecules（such as CH3 F, CH3 Cl, and CH3CF3） are calculated. Moreover, CO2 and N2O are also studied with the modified 3CLJDQP model. The calculated results from the modified 2CLJDQP model accord better with the experimental data than those from the original model.It is shown that the presented model improves the positive deviation in low temperature range and negative deviation in high temperature range. So the modified 2CLJDQP potential model with the temperature-dependent parameters can be employed satisfactorily in large temperature range.
基金The project supported by National Natural Science Foundation of China.
文摘In this paper a new relation between the second virial coefficients A_2, (?)_w and (dV_(es)/dC)_c→0=K_s was derived from proposed model theory of concentration effects in GPC for mono-and poly-dispersed polymers. Based on this relation a new method for determination of second vifial coefficients from the combination of (dV_(es)/dC)_c→0=K_3, (?)_w and K_H measurements was proposed.The values of A_2 for mono-and poly-dispersed polystyrenes with molecular weight range from 10~4 to 10~6 in good and theta solvents were determined by proposed method. Results show that their values of A_2 are in agreement with those obtained by light scattering.
基金The work is supported by UKM grant ST-028-2003 IRPA grant 09-02-02-80 EA208, Malysia.
文摘In this paper we consider the class ∑^＊（p,α,β,k,c） consisting of analytic functions with negativecoefficients and fixed second coefficient. The object of the present paper is to give coefficient estimates, convex linear combinations, some distortion theorems and radii of starlikeness and convexity for f（z） in the class ∑^＊（p,α,β,k,c） .
文摘In this paper, we investigate some argument properties for analytic functions with fixed second coefficient and positive real part. And we apply the argument properties to the functions that are analytic and normalized. In particular, the order of strongly starlikeness of strongly convex functions with fixed second coefficients is given.
基金Supported by Shanghai Leading Academic Displine Project(No.B604)
文摘Refrigeration coefficient, ε, is usually calculated by using the First Law of Thermodynamics. In this paper, a new derivation process is introduced through the combination of the Second Law of Thermodynamics with the First Law of Thermodynamics. As a result, two new calculation equations for refrigeration coefficient are proposed. One equation is equivalent to the common method, but its form is a little complicated for real calculation. Another equation is the further simplification, and can be used to calculate the refrigeration coefficient instead of common method with a oermit error.
基金Project supported by China Post-Doctoral Science Foundation(No.2004036239)
文摘A two-scale second-order moment two-phase turbulence model accounting for inter-particle collision is developed, based on the concept of particle large-scale fluctuation due to turbulence and particle small-scale fluctuation due to collision. The proposed model is used to simulate gas-particle downer reactor flows. The computational results of both particle volume fraction and mean velocity are in agreement with the experimental results. After analyzing effects of empirical coefficient on prediction results, we can come to a conclusion that, inside the limit range of empirical coefficient, the predictions do not reveal a large sensitivity to the empirical coefficient in the downer reactor, but a relatively great change of the constants has important effect on the prediction.
基金Project supported by the National Natural Science Foundation of China(Grant No.11471262)the National Basic Research Program of China(Grant No.2012CB025904)the State Key Laboratory of Science and Engineering Computing and the Center for High Performance Computing of Northwestern Polytechnical University,China
文摘We study the hyperbolic–parabolic equations with rapidly oscillating coefficients. The formal second-order two-scale asymptotic expansion solutions are constructed by the multiscale asymptotic analysis. In addition, we theoretically explain the importance of the second-order two-scale solution by the error analysis in the pointwise sense. The associated explicit convergence rates are also obtained. Then a second-order two-scale numerical method based on the Newmark scheme is presented to solve the equations. Finally, some numerical examples are used to verify the effectiveness and efficiency of the multiscale numerical algorithm we proposed.
基金Funded by the National Natural Science Foundation of China (No.50879079)Science and Technology Plan Project of Zhejiang Province (No.2007C23058)
文摘According to the existing concrete core samples obtained in site, chloride concentration and porosity of existing normal hydraulic concrete were measured, and chloride diffusivity in existing hydraulic concrete was studied. By Fick’s second law, the chloride diffusion coefficients in the steady diffusion area were calculated. The chloride diffusion of different mix proportion concrete was tested, and chloride diffusion coefficients and porosities of freshly concrete were measured, moreover, the relationship between diffusion coefficient and porosity was analyzed. The results show that the varying law of chloride diffusion coefficient with exposure time of existing concrete can be predicted in a better way by Fick’s second law and water-cement ratios or porosity of concrete and chloride concentration in existing concrete.
