In the present paper the Lie symmetrical non-Noether conserved quantity of the Poincaré Chetaev equations of a generalized classical mechanics under the general infinitesimal transformations of Lie groups is disc...In the present paper the Lie symmetrical non-Noether conserved quantity of the Poincaré Chetaev equations of a generalized classical mechanics under the general infinitesimal transformations of Lie groups is discussed. First, we establish the determining equations of Lie symmetry of the equations. Second, the Lie symmetrical non-Noether conserved quantity of the equations is deduced. Finally, an example is given to illustrate the application of the results.展开更多
Calculations have been performed to investigate the pressure-induced solid-solid phase transitions and the mechanical stability for three zinc-blende II-VI semiconductor compounds： ZnS, ZnSe, ZnTe by ab initio plane-...Calculations have been performed to investigate the pressure-induced solid-solid phase transitions and the mechanical stability for three zinc-blende II-VI semiconductor compounds： ZnS, ZnSe, ZnTe by ab initio plane-wave pseudopotential density functional theory （DFT）. Using the generalized gradient approximation （GGA） for exchange and correlation in the scheme of Perdew-Wang 1991 （P Wgl ）, the ground state properties and equation of state are obtained, which are well consistent with the experimental data available and other calculations. On the basis of the forth-order Birch-Murnaghan equation of states, the transition pressures Pt are determined through the analysis of enthalpy variation with pressure. A linear-response approach is used to calculate the frequencies of the phonon dispersion. Finally, by the calculations of phonon frequencies, some thermodynamic properties such as the vibrational contribution to the Helmholtz free energy （F）, enthedpy （H）, entropy （S）, and the heat capacity （Cv ） are also successfully obtained.展开更多
By the application of the extended homogeneous balance method, we derive anauto-Backlund transformation (BT) for (2+1)-dimensional variable coefficient generalized KPequations. Based on the BT, in which there are two ...By the application of the extended homogeneous balance method, we derive anauto-Backlund transformation (BT) for (2+1)-dimensional variable coefficient generalized KPequations. Based on the BT, in which there are two homogeneity equations to be solved, we obtainsome exact solutions containing single solitary waves.展开更多
文摘In the present paper the Lie symmetrical non-Noether conserved quantity of the Poincaré Chetaev equations of a generalized classical mechanics under the general infinitesimal transformations of Lie groups is discussed. First, we establish the determining equations of Lie symmetry of the equations. Second, the Lie symmetrical non-Noether conserved quantity of the equations is deduced. Finally, an example is given to illustrate the application of the results.
基金Support by the National Natural Science Foundation of China under Grant No.10776022the National Key Laboratory Fund for Shock Wave and Detonation Physics Research of the China Academy of Engineering Physics and the Specialized Research Fund for the Doctoral Program of Higher Education under Grant No.20090181110080
文摘Calculations have been performed to investigate the pressure-induced solid-solid phase transitions and the mechanical stability for three zinc-blende II-VI semiconductor compounds： ZnS, ZnSe, ZnTe by ab initio plane-wave pseudopotential density functional theory （DFT）. Using the generalized gradient approximation （GGA） for exchange and correlation in the scheme of Perdew-Wang 1991 （P Wgl ）, the ground state properties and equation of state are obtained, which are well consistent with the experimental data available and other calculations. On the basis of the forth-order Birch-Murnaghan equation of states, the transition pressures Pt are determined through the analysis of enthalpy variation with pressure. A linear-response approach is used to calculate the frequencies of the phonon dispersion. Finally, by the calculations of phonon frequencies, some thermodynamic properties such as the vibrational contribution to the Helmholtz free energy （F）, enthedpy （H）, entropy （S）, and the heat capacity （Cv ） are also successfully obtained.
文摘By the application of the extended homogeneous balance method, we derive anauto-Backlund transformation (BT) for (2+1)-dimensional variable coefficient generalized KPequations. Based on the BT, in which there are two homogeneity equations to be solved, we obtainsome exact solutions containing single solitary waves.
