The electronic structure of FeAl was determined by one cell state method and the curve of potential energy, lattice constant, cohesive energy, bulk elastic modulus, and the variation of linear thermal expansion coeffi...The electronic structure of FeAl was determined by one cell state method and the curve of potential energy, lattice constant, cohesive energy, bulk elastic modulus, and the variation of linear thermal expansion coefficient with temperature were calculated. It was found that most of the theoretical values of these properties above are in good agreement with experimental ones. The relationship between electronic bonding and crystal structure/brittleness was discussed by using the calculated electronic structure.展开更多
A new direct approach based on the separation of variables for the study of soliton perturbations is developed.As an example,the effects of perturbation on a soliton(kink),i.e.,both the time-dependence of soliton para...A new direct approach based on the separation of variables for the study of soliton perturbations is developed.As an example,the effects of perturbation on a soliton(kink),i.e.,both the time-dependence of soliton parameters and the first-order correction are derived for perturbed sine-Gordon equation.Our approach is very concise and easy to understand,and it can be extended directly to deal with other nonlinear evolution equations.展开更多
Perturbations about kink solution ofФ-4 equation are investigated by a direct approach which was recently developed in a study of soliton perturbation theory.In this scheme,the derivative expansion method from classi...Perturbations about kink solution ofФ-4 equation are investigated by a direct approach which was recently developed in a study of soliton perturbation theory.In this scheme,the derivative expansion method from classical perturbation theory is employed to linearize the perturbed equation.The solution of the linearized equation for first-order correction is derived by the method of Laplace transformation.At the same time,the parameters variation is obtained directly from the secularity conditions.展开更多
文摘The electronic structure of FeAl was determined by one cell state method and the curve of potential energy, lattice constant, cohesive energy, bulk elastic modulus, and the variation of linear thermal expansion coefficient with temperature were calculated. It was found that most of the theoretical values of these properties above are in good agreement with experimental ones. The relationship between electronic bonding and crystal structure/brittleness was discussed by using the calculated electronic structure.
文摘A new direct approach based on the separation of variables for the study of soliton perturbations is developed.As an example,the effects of perturbation on a soliton(kink),i.e.,both the time-dependence of soliton parameters and the first-order correction are derived for perturbed sine-Gordon equation.Our approach is very concise and easy to understand,and it can be extended directly to deal with other nonlinear evolution equations.
文摘Perturbations about kink solution ofФ-4 equation are investigated by a direct approach which was recently developed in a study of soliton perturbation theory.In this scheme,the derivative expansion method from classical perturbation theory is employed to linearize the perturbed equation.The solution of the linearized equation for first-order correction is derived by the method of Laplace transformation.At the same time,the parameters variation is obtained directly from the secularity conditions.
