We develop a semiclassical model to describe the non-sequential double ionization of diatomic molecules in an intense linearly polarized field, achieving insight into the two-electron correlation effect in the ionizat...
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We develop a semiclassical model to describe the non-sequential double ionization of diatomic molecules in an intense linearly polarized field, achieving insight into the two-electron correlation effect in the ionization dynamics. Compared to the experimental data of nitrogen molecules, our model shows a good agreement in the tunnelling regime and a qualitative agreement in the over-barrier regime. We find that the classical collisional trajectories are the main source of the double ionization in the tunnelling regime. As a prediction of our theory, we also calculate the double ionization ratios of H2^2＋/H2^＋ for hydrogen molecules and predict a ratio less than that of nitrogen molecules.
Substitution is among the effective methods to modify essential properties of graphene nanoribbons (GNRs) allowing them to be adaptive to a wide range of applications. In this study, the spin-polarized DFT calculation...
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As an important model in quantum semiconductor devices, the SchrSdinger-Poisson equations have generated widespread interests in both analysis and numerical simulations in recent years. In this paper, we present Gauss...
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As an important model in quantum semiconductor devices, the SchrSdinger-Poisson equations have generated widespread interests in both analysis and numerical simulations in recent years. In this paper, we present Gaussian beam methods for the numerical simulation of the one-dimensional Schrodinger-Poisson equations. The Gaussian beam methods for high frequency waves outperform the geometrical optics method in that the former are accurate even around caustics. The purposes of the paper are first to develop the Gaussian beam methods, based on our previous methods for the linear SchrSdinger equation, for the Schrodinger-Poisson equations, and then check their validity for this weakly-nonlinear system.
The simplex algorithm is a widely used method for solving a linear programming problem (LP) which is first presented by George B. Dantzig. One of the important steps of the simplex algorithm is applying an appropriate...
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ISBN:
(纸本)9789881925336
The simplex algorithm is a widely used method for solving a linear programming problem (LP) which is first presented by George B. Dantzig. One of the important steps of the simplex algorithm is applying an appropriate pivot rule, the rule to select the entering variable. An effective pivot rule can lead to the optimal solution of LP with the small number of iterations. In a minimization problem, Dantzig's pivot rule selects an entering variable corresponding to the most negative reduced cost. The concept is to have the maximum improvement in the objective value per unit step of the entering variable. However, in some problems, Dantzig's rule may visit a large number of extreme points before reaching the optimal solution. In this paper, we propose a pivot rule that could reduce the number of such iterations over the Dantzig's pivot rule. The idea is to have the maximum improvement in the objective value function by trying to block a leaving variable that makes a little change in the objective function value as much as possible. Then we test and compare the efficacy of this rule with Dantzig' original rule.
Using a variational approach,the propagation of a moderately intense laser pulse in a parabolic preformed plasma channel is *** effects of higher-order relativistic nonlinearity (HRN) and wakefield are *** effect of H...
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Using a variational approach,the propagation of a moderately intense laser pulse in a parabolic preformed plasma channel is *** effects of higher-order relativistic nonlinearity (HRN) and wakefield are *** effect of HRN serves as an additional defocusing mechanism and has the same order of magnitude in the spot size as that of the transverse wakefield (TWF).The effect of longitudinal wakefield is much larger than those of HRN and TWF for an intense laser pulse with the pulse length equaling the plasma *** catastrophic focusing of the laser spot size would be prevented in the present of HRN and then it varies with periodic focusing oscillations.
The aerodynamics of freely falling objects is one of the most interesting flow mechanics *** a recent study,Andersen,Pesavento,and Wang[*** Mech.,vol.541,pp.65-90(2005)]presented the quantitative comparison between th...
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The aerodynamics of freely falling objects is one of the most interesting flow mechanics *** a recent study,Andersen,Pesavento,and Wang[*** Mech.,vol.541,pp.65-90(2005)]presented the quantitative comparison between the experimental measurement and numerical *** rich dynamical behavior,such as fluttering and tumbling motion,was ***,obvious discrepancies between the experimental measurement and numerical simulations still *** the current study,a similar numerical computation will be conducted using a newly developed unified coordinate gas-kinetic method[***,vol.222,pp.155-175(2007)].In order to clarify some early conclusions,both elliptic and rectangular falling plates will be *** the experimental condition,the numerical solution shows that the averaged translational velocity for both rectangular and elliptical plates are almost identical during the tumbling ***,the plate rotation depends strongly on the shape of the *** this study,the details of fluid forces and torques on the plates and plates movement trajectories will be presented and compared with the experimental measurements.
The optical guiding of a moderately intense laser pulse in a parabolic preformed plasma channel is analyzed by means of the variational ***,ponderomotive and their coupling nonlinearities are *** conditions for period...
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The optical guiding of a moderately intense laser pulse in a parabolic preformed plasma channel is analyzed by means of the variational ***,ponderomotive and their coupling nonlinearities are *** conditions for periodic defocusing and focusing,as well as constant spot size propagation are *** is found that the laser focusing is released by the coupling of relativistic and ponderomotive nonlinearities.
This paper presents an Eulerian diffuse-interface method using a high-order compact difference scheme for simulating elastic-plastic flows with the Mie–Gruneisen(MG)equation of state(EoS).For simulations of multimate...
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This paper presents an Eulerian diffuse-interface method using a high-order compact difference scheme for simulating elastic-plastic flows with the Mie–Gruneisen(MG)equation of state(EoS).For simulations of multimaterial problems,numerical errors were generated in the material discontinuities owing to inconsistent treatment of the convective *** on the normal-stress-based mechanical equilibrium assumption for elastic-plastic solids,we introduce an improved form of the consistent localized artificial diffusivity(LAD)method to ensure an oscillation-free interface for velocity and normal *** proposed algorithm uses a hyperelastic model.A mixture type of the model system was formed by combining the conservation equations for the basic conserved variables,an equation of a unified deviatoric tensor describing solid deformation,and an additional set of equations for solving the material quantities in the MG *** one-and two-dimensional problems with various discontinuities,including the elastic-plastic Richtmyer–Meshkov instability,were considered for testing the proposed method.
Models for learning probability distributions such as generative models and density estimators behave quite differently from models for learning functions. One example is found in the memorization phenomenon, namely t...
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The flow in a channel with its lower wall mounted with streamwise V-shaped riblets is simulated using a highly efficient spectral-element-Fourier method. The range of Reynolds numbers investigated is 500 to 4000, whic...
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