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991.
992.
A biomathematical model is described by stochastic differential equations with Markovian switching. The long‐time dynamical properties are studied both theoretically and numerically. Results show that both the persistence and extinction have close relationship with environmental noises (white and color noises). These results are of important biological significance for biological conservation. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
993.
Mimmo Iannelli Gabriela Marinoschi 《Mathematical Methods in the Applied Sciences》2013,36(10):1229-1239
The basic linear model for describing an age structured population spreading in a limited habitat is considered with the purpose of investigating an approximation procedure based on parabolic regularization. In fact, a viscosity model is introduced by considering an appropriate approximating regularized parabolic problem and it is proved that the sequence of the approximating solutions tends to the solution to the original problem. The advantage of this approach is that it leads to the numerical solution of a parabolic problem that has more stable solutions than the hyperbolic‐parabolic original problem and avoids the restrictions (compatibility conditions) needed to treat the latter. Moreover, for the solution of the approximating problem, it is possible to take advantage of established software packages dedicated to parabolic problems. Some examples of the approach are provided using COMSOL Multiphysics. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
994.
Steffen Roch 《Numerical Functional Analysis & Optimization》2013,34(1-2):241-253
The paper deals with spectral approximation of Wiener-Hopf operators acting on Lp -spaces by their finite sections. The generating functions of the Wiener-Hopf operators are supposed to be continuous plus almost periodic.While the usual spectra of the finite sections drastically fail to converge to the spectrum of the Wiener-Hopf operator,it turns out that other spectral approximants, viz. the pseudospectra and the numerical ranges, do converge perfectly.The proof requires a modified approach to the finite section method for Wiener-Hopf operators. This note generalizes results obtained by Böttcher, Grudsky and Silbermann for the case of continuous generating functions. 相似文献
995.
H. Xiao D. Z. Yao C. X. Wang S. Chen 《The European Physical Journal B - Condensed Matter and Complex Systems》2008,64(2):219-229
The absolute photonic band gap (PBG) in two-dimensional (2D) photonic crystal with excentric core-shell rods is studied in
this paper. The core rod shifts away from the core-shell rod center, and its position is decided by two new introduced parameters
— the shift angle θ and the offset ρ. We use the FDTD algorithm to calculate the photonic bands of the photonic crystal, and analyze how the offset and shift
angle affect the photonic bang gap of excentric core-shell photonic crystal for different core rod size. It has been shown
that the variation of the photonic band gap is quite peculiar. 相似文献
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999.
ZHONG Wei-Ping YI Lin YANG Zheng-Ping XIE Rui-Hua BELIC Milivoj CHEN Goong 《理论物理通讯》2008,50(9):749-752
Collisions of spatial solitons occurring in the nonlinear Schroeinger equation with harmonic potential are studied, using conservation laws and the split-step Fourier method. We find an analytical solution for the separation distance between the spatial solitons in an inhomogeneous nonlinear medium when the light beam is self-trapped in the transverse dimension. In the self-focusing nonlinear media the spatial solitons can be transmitted stably, and the interaction between spatial solitons is enhanced due to the linear focusing effect (and also diminished for the linear defocusing effect). In the self-defocusing nonlinear media, in the absence of self-trapping or in the presence of linear self-defocusing, no transmission of stable spatial solitons is possible. However, in such media the linear focusing effect can be exactly compensated, and the spatial solitons can propagate through. 相似文献
1000.
AN Hong-Li LI Yong-Zhi CHEN Yong 《理论物理通讯》2008,50(9):568-574
In this paper, we directly extend the applications of the Adomian decomposition method to investigate the complex KdV equation. By choosing different forms of wave functions as the initial values, three new types of realistic numerical solutions: numerical positon, negaton solution, and particularly the numerical analytical complexiton solution are obtained, which can rapidly converge to the exact ones obtained by Lou et al. Numerical simulation figures are used to illustrate the efficiency and accuracy of the proposed method. 相似文献