TN252 96321131 基于等效衰减矢方法的非均匀光波导色散方程=Dispersion equation of inhomogeneous planaroptical waveguides based on concept of equiv- alent attenuated vactor[刊,中]/詹黎,曹庄琪(上海交通大学应用物理系。上海(...TN252 96321131 基于等效衰减矢方法的非均匀光波导色散方程=Dispersion equation of inhomogeneous planaroptical waveguides based on concept of equiv- alent attenuated vactor[刊,中]/詹黎,曹庄琪(上海交通大学应用物理系。上海(200030))∥光学学报。—1995,15(8)。—1053—1058 利用转移矩阵理论和等效衰减矢的概念。展开更多
A single-mode optical fiber with a convex chromatic dispersion profile is proposed for generating a flat supercontinuum(SC).The fiber has normal dispersion and the dispersion parameter D(λ,z) is a convex function of ...A single-mode optical fiber with a convex chromatic dispersion profile is proposed for generating a flat supercontinuum(SC).The fiber has normal dispersion and the dispersion parameter D(λ,z) is a convex function of wavelengths.It is shown from the numerical results that the chromatic dispersion,the flatness of the dispersion curve and the pump conditions have significant effect on SC generation.A flat and broad SC without strong residual pump component can be obtained when the pump wavelength is set in the vicinity of the wavelength at which the fiber has small normal group-velocity dispersion(GVD) and small dispersion slope.The fiber with a smaller normal GVD,a flatter dispersion profile and a higher nonlinear coefficient are more suitable for broad SC generation.展开更多
This paper presents a simple solution of the dynamic buckling of stiffened plates under in-plane impact loading. Based on large deflection theory, a discretely stiffened plate model has been used. The tangential stres...This paper presents a simple solution of the dynamic buckling of stiffened plates under in-plane impact loading. Based on large deflection theory, a discretely stiffened plate model has been used. The tangential stresses of stiffeners and in-plane displacement are neglected. Appling the Hamilton's principle, the motion equations of stiffened plates are obtained. The deflection of the plate is taken as Fourier series, and using Galerkin method the discrete equations can be deduced, which can be solved easily by Runge-Kutta method. The dynamic buckling loads of the stiffened plates are obtained form Budiansky-Roth criterion.展开更多
Due to the complexity of compressible flows,nonlinear hydrodynamic stability theories in supersonic boundary layers are not sufficient.In order to reveal the nonlinear interaction mechanisms of the rapidly amplified 3...Due to the complexity of compressible flows,nonlinear hydrodynamic stability theories in supersonic boundary layers are not sufficient.In order to reveal the nonlinear interaction mechanisms of the rapidly amplified 3-D disturbances in supersonic boundary layers at high Mach numbers,the nonlinear evolutions of different disturbances in flat-plate boundary layers at Mach number 4.5,6 and 8 are analyzed by numerical simulations.It can be concluded that the 3-D disturbances are amplified rapidly when the amplitude of the 2-D disturbance reaches a certain level.The most rapidly amplified 3-D disturbances are Klebanoff type(K-type)disturbances which have the same frequency as the 2-D disturbance.Among these K-type 3-D disturbances,the disturbances located at the junction of upper branch and lower branch of the neutral curve are amplified higher.Through analyzing the relationship between the amplification rate and the spanwise wavenumber of the 3-D disturbances at different evolution stages,the mechanism of the spanwise wavenumber selectivity of K-type 3-D disturbances in the presence of a finite amplitude 2-D disturbance is explained.展开更多
文摘TN252 96321131 基于等效衰减矢方法的非均匀光波导色散方程=Dispersion equation of inhomogeneous planaroptical waveguides based on concept of equiv- alent attenuated vactor[刊,中]/詹黎,曹庄琪(上海交通大学应用物理系。上海(200030))∥光学学报。—1995,15(8)。—1053—1058 利用转移矩阵理论和等效衰减矢的概念。
基金National Basic Research Program of China(2003CB314906)
文摘A single-mode optical fiber with a convex chromatic dispersion profile is proposed for generating a flat supercontinuum(SC).The fiber has normal dispersion and the dispersion parameter D(λ,z) is a convex function of wavelengths.It is shown from the numerical results that the chromatic dispersion,the flatness of the dispersion curve and the pump conditions have significant effect on SC generation.A flat and broad SC without strong residual pump component can be obtained when the pump wavelength is set in the vicinity of the wavelength at which the fiber has small normal group-velocity dispersion(GVD) and small dispersion slope.The fiber with a smaller normal GVD,a flatter dispersion profile and a higher nonlinear coefficient are more suitable for broad SC generation.
文摘This paper presents a simple solution of the dynamic buckling of stiffened plates under in-plane impact loading. Based on large deflection theory, a discretely stiffened plate model has been used. The tangential stresses of stiffeners and in-plane displacement are neglected. Appling the Hamilton's principle, the motion equations of stiffened plates are obtained. The deflection of the plate is taken as Fourier series, and using Galerkin method the discrete equations can be deduced, which can be solved easily by Runge-Kutta method. The dynamic buckling loads of the stiffened plates are obtained form Budiansky-Roth criterion.
基金supported by the State Key Program of National Natural Science Foundation of China(Grant No.11332007)
文摘Due to the complexity of compressible flows,nonlinear hydrodynamic stability theories in supersonic boundary layers are not sufficient.In order to reveal the nonlinear interaction mechanisms of the rapidly amplified 3-D disturbances in supersonic boundary layers at high Mach numbers,the nonlinear evolutions of different disturbances in flat-plate boundary layers at Mach number 4.5,6 and 8 are analyzed by numerical simulations.It can be concluded that the 3-D disturbances are amplified rapidly when the amplitude of the 2-D disturbance reaches a certain level.The most rapidly amplified 3-D disturbances are Klebanoff type(K-type)disturbances which have the same frequency as the 2-D disturbance.Among these K-type 3-D disturbances,the disturbances located at the junction of upper branch and lower branch of the neutral curve are amplified higher.Through analyzing the relationship between the amplification rate and the spanwise wavenumber of the 3-D disturbances at different evolution stages,the mechanism of the spanwise wavenumber selectivity of K-type 3-D disturbances in the presence of a finite amplitude 2-D disturbance is explained.
