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931.
Spatial Vector Solitons in Nonlinear Photonic Crystal Fibers 总被引:1,自引:0,他引:1
José R. Salgueiro Yuri S. Kivshar Dmitry E. Pelinovsky Verónica Simón Humberto Michinel 《Studies in Applied Mathematics》2005,115(2):157-171
We study spatial vector solitons in a photonic crystal fiber (PCF) made of a material with the focusing Kerr nonlinearity. We show that such two-component localized nonlinear waves consist of two mutually trapped components confined by the PCF linear and the self-induced nonlinear refractive indices, and they bifurcate from the corresponding scalar solitons. We demonstrate that, in a sharp contrast with an entirely homogeneous nonlinear Kerr medium where both scalar and vector spatial solitons are unstable and may collapse, the periodic structure of PCF can stabilize the otherwise unstable two-dimensional spatial optical solitons. We apply the matrix criterion for stability of these two-parameter solitons, and verify it by direct numerical simulations. 相似文献
932.
Mathematical models with stage structures are proposed to describe the process of awareness, evaluation and decision-making. First, a system of ordinary differential equations is presented that incorporates the awareness stage and the decision-making stage. If the adoption rate is bilinear and imitations are dominant, we find a threshold above which innovation diffusion is successful. Further, if the adoption rate has a higher nonlinearity, it is shown that there exist bistable equilibria and a region such that an innovation diffusion is successful inside and is unsuccessful outside. Secondly, a model with a time delay is proposed that includes an evaluation stage of a product. It is proved that the system exhibits stability switches. The bifurcation direction of equilibria is also discussed. 相似文献
933.
In this work two non-local problems for the parabolic-hyperbolic type equation with non-characteristic line of changing type
are considered. Unique solvability of these problems is proven. The uniqueness of the solution is proven by the method of
energy integrals and the existence is proven by the method of integral equations. 相似文献
934.
Jean-Marc Hérard 《Comptes Rendus Mathematique》2006,342(10):779-784
We introduce a hyperbolic entropy-consistent model to describe three-phase flows, which ensures that void fractions, mass fractions and pressures remain positive through single waves occurring in the one dimensional solution of the Riemann problem. To cite this article: J.-M. Hérard, C. R. Acad. Sci. Paris, Ser. I 342 (2006). 相似文献
935.
This Note deals with optimal control problems with only one control variable and one state constraint, of arbitrary order. We consider the case of finitely many boundary arcs and touch times. We obtain a no-gap theory of second-order conditions, allowing us to characterize second-order quadratic growth. To cite this article: J.F. Bonnans, A. Hermant, C. R. Acad. Sci. Paris, Ser. I 343 (2006). 相似文献
936.
J.H. Sung J.Y. Park T. Imran Y.S. Lee C.H. Nam 《Applied physics. B, Lasers and optics》2006,82(1):5-8
Optical pulses with 1.1-mJ energy and 5.5-fs duration have been generated at 1-kHz repetition rate from a chirped pulse amplification
Ti:Sapphire laser incorporating a differentially pumped hollow-fiber chirped-mirror compressor. The effects of self-focusing
and multi-photon ionization during the beam propagation were minimized by differentially pumping the hollow fiber filled with
neon. The spectral broadening at the hollow-fiber compressor was optimized by adjusting gas pressure, laser intensity, and
laser chirp, covering from 540 nm to 950 nm.
PACS 42.65.Jx; 42.65.Re 相似文献
937.
Present paper deals with the structural, magnetic and transport studies of as-deposited as well as annealed Co/GaAs(0 0 1) thin film at different temperatures. The X-ray diffraction measurements show oriented growth of as-deposited Co film in the hcp (0 0 2) direction. However, the sample annealed at higher temperatures shows formation of ternary Co2GaAs phase at the interface. Corresponding magnetic and transport measurements show decrement in magnetization and resistivity with annealing temperatures. The observed reductions in magnetization and resistivity values are mainly attributed to the formation of ternary Co2GaAs phase at the interface. 相似文献
938.
The energies of negative-parity levels based on two-particle states exhibit a nonlinear behavior at low spins versus the core-rotation energy because the alignment process has not yet been completed for them. This behavior of negative-parity levels in the low-spin region is satisfactorily described upon the inclusion of octupole-octupole interactions. This is demonstrated within the rotational model involving the Coriolis mixing of states for the even-even isotopes 162–168Hf. 相似文献
939.
Magnetic-structure distortions induced by an external magnetic field near a rough surface of a uniaxial collinear antiferromagnet are analyzed using mathematical modeling. The “magnetic field-roughness” phase diagram of these distortions is constructed. It is demonstrated that, under specific conditions, the presence of atomic steps leads to the formation of domains in the surface layer of the antiferromagnet. In the case of a strong roughness, there arise static vortices at the surface and a 90° domain wall aligned parallel to the surface of the antiferromagnet. 相似文献
940.
O. M. Zhigalina K. A. Vorotilov A. S. Sigov A. S. Kumskov 《Physics of the Solid State》2006,48(6):1205-1207
Barium strontium titanate (BST) films on Si-SiO2-Ti-Pt substrates are prepared by chemical solution deposition upon crystallization on a sublayer. The structure of the BST films is investigated using transmission electron microscopy, high-resolution electron microscopy, and x-ray diffraction analysis. 相似文献