The oscillatory behavior of neutral differential equation with positive and negative coefficients is investigated by mathematics analysis technique and the fixed point principle. Some sufficient conditions for oscilla...The oscillatory behavior of neutral differential equation with positive and negative coefficients is investigated by mathematics analysis technique and the fixed point principle. Some sufficient conditions for oscillation of neutral differential equation with positive and negative coefficients are obtained.展开更多
A U(2) algebraic model is introduced for the spectrum of a molecule XY4, where the interactions between the stretch and bend modes are described by Td symmetric Fermi resonance terms. The presented algebraic model in ...A U(2) algebraic model is introduced for the spectrum of a molecule XY4, where the interactions between the stretch and bend modes are described by Td symmetric Fermi resonance terms. The presented algebraic model in a limit corresponds to another model in recent literature. The vibrational spectrum of methane (CH4) measured recently with modern spectroscopy techniques is employed to test those models. The obtained standard deviation between the observed and the calculated vibrational energy levels in the algebraic model is smaller than that in the corresponding model.展开更多
Rain-wind-induced vibration of cable was studied based on previous research achievements. According to the quasi-steady assumption, the governing equation of vertical motion of the cable was derived and the criterion ...Rain-wind-induced vibration of cable was studied based on previous research achievements. According to the quasi-steady assumption, the governing equation of vertical motion of the cable was derived and the criterion for unstable motion and occurrence mechanism was studied. A comparison was performed between the oscillation responses of the stay cable obtained from calculated model and previous results. The results indicate that the analysis model can reflect the main characteristics of wind-rain-induced vibrationt of the cable which is amplitude- and velocity-restricted, and it is probably related with the periodic vortex shedding of wake flow. It is essential for the occurrence of rain-wind-induced or wind-induced vibration of cable that the derivative of lift coefficient with respect to transient angle of attack is less than zero. When rain-wind-induced vibration occurs, the aerodynamic force has a dual function for the vibration, and the maximum amplitude of stayed-cable is determined by the relative value of aerodynamic exciting force and aerodynamic damping force.展开更多
U(3)-O(4) transitional description of diatomic molecules in the U(4) vibron model is studied by usingthe algebraic Bethe ansatz, in which the O(4) limit is a special case of the theory. Vibrational band-heads of somet...U(3)-O(4) transitional description of diatomic molecules in the U(4) vibron model is studied by usingthe algebraic Bethe ansatz, in which the O(4) limit is a special case of the theory. Vibrational band-heads of sometypical diatomic molecules are fitted by both transitional theory and the O(4) limit within the same framework. Theresults show that there are evident deviations from the O(4) limit in description of vibrational spectra of some diatomicmolecules.展开更多
A new finite element modeling method has been developed using laminate theory in a virtual work principle for active constraining layer damping plate. The frequency dependent modulus of viscoelastic material is descri...A new finite element modeling method has been developed using laminate theory in a virtual work principle for active constraining layer damping plate. The frequency dependent modulus of viscoelastic material is described by introducing a few dissipation coordinates, known as GHM (Golla-Hughes-McTavish) method, a standard linear system with constant coefficient. The effectiveness of this method is validated by experimental model. Compared with conventional methods, this method can reduce a number of degrees of freedom and improve accuracy, provides a good model for analogous configurations.展开更多
This paper, we discuss a class of second order nonlinear neutral differential equations with variable coefficients and variable deviations， Sharp conditions are established for all bounded solutions of the equations ...This paper, we discuss a class of second order nonlinear neutral differential equations with variable coefficients and variable deviations， Sharp conditions are established for all bounded solutions of the equations to be oscillatory， Linearized oscillation criteria of the equations are also given，展开更多
文摘The oscillatory behavior of neutral differential equation with positive and negative coefficients is investigated by mathematics analysis technique and the fixed point principle. Some sufficient conditions for oscillation of neutral differential equation with positive and negative coefficients are obtained.
文摘A U(2) algebraic model is introduced for the spectrum of a molecule XY4, where the interactions between the stretch and bend modes are described by Td symmetric Fermi resonance terms. The presented algebraic model in a limit corresponds to another model in recent literature. The vibrational spectrum of methane (CH4) measured recently with modern spectroscopy techniques is employed to test those models. The obtained standard deviation between the observed and the calculated vibrational energy levels in the algebraic model is smaller than that in the corresponding model.
基金Project(51078170) supported by the National Natural Science Foundation of ChinaProject(10JDG097) supported by Jiangsu University Talents Funds,China
文摘Rain-wind-induced vibration of cable was studied based on previous research achievements. According to the quasi-steady assumption, the governing equation of vertical motion of the cable was derived and the criterion for unstable motion and occurrence mechanism was studied. A comparison was performed between the oscillation responses of the stay cable obtained from calculated model and previous results. The results indicate that the analysis model can reflect the main characteristics of wind-rain-induced vibrationt of the cable which is amplitude- and velocity-restricted, and it is probably related with the periodic vortex shedding of wake flow. It is essential for the occurrence of rain-wind-induced or wind-induced vibration of cable that the derivative of lift coefficient with respect to transient angle of attack is less than zero. When rain-wind-induced vibration occurs, the aerodynamic force has a dual function for the vibration, and the maximum amplitude of stayed-cable is determined by the relative value of aerodynamic exciting force and aerodynamic damping force.
基金The project supported by National Natural Science foundation of China under Grant No.10175031the Natural Science Foundation of Liaoning Province of China under Grant No.2001101053
文摘U(3)-O(4) transitional description of diatomic molecules in the U(4) vibron model is studied by usingthe algebraic Bethe ansatz, in which the O(4) limit is a special case of the theory. Vibrational band-heads of sometypical diatomic molecules are fitted by both transitional theory and the O(4) limit within the same framework. Theresults show that there are evident deviations from the O(4) limit in description of vibrational spectra of some diatomicmolecules.
文摘A new finite element modeling method has been developed using laminate theory in a virtual work principle for active constraining layer damping plate. The frequency dependent modulus of viscoelastic material is described by introducing a few dissipation coordinates, known as GHM (Golla-Hughes-McTavish) method, a standard linear system with constant coefficient. The effectiveness of this method is validated by experimental model. Compared with conventional methods, this method can reduce a number of degrees of freedom and improve accuracy, provides a good model for analogous configurations.
文摘This paper, we discuss a class of second order nonlinear neutral differential equations with variable coefficients and variable deviations， Sharp conditions are established for all bounded solutions of the equations to be oscillatory， Linearized oscillation criteria of the equations are also given，
