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101.
We consider soliton solutions of a two-dimensional nonlinear system with the self-focusing nonlinearity and a quasi 1D confining potential, taking harmonic potential as an example. We investigate a single soliton in detail and find criterion for possible collapse. This information is then used to investigate the dynamics of the two soliton collision. In this dynamics we identify three regimes according to the relation between nonlinear interaction and the excitation energy: elastic collision, excitation and collapse regime. We show that surprisingly accurate predictions can be obtained from variational analysis. 相似文献
102.
A multiple scales technique is employed to solve the fluid-Maxwell equations describing a weakly nonlinear circularly polarized electromagnetic pulse in magnetized plasma. A nonlinear Schrödinger-type (NLS) equation is shown to govern the amplitude of the vector potential. The conditions for modulational instability and for the existence of various types of localized envelope modes are investigated in terms of relevant parameters. Right-hand circularly polarized (RCP) waves are shown to be modulationally unstable regardless of the value of the ambient magnetic field and propagate as bright-type solitons. The same is true for left-hand circularly polarized (LCP) waves in a weakly to moderately magnetized plasma. In other parameter regions, LCP waves are stable in strongly magnetized plasmas and may propagate as dark-type solitons (electric field holes). The evolution of envelope solitons is analyzed numerically, and it is shown that solitons propagate in magnetized plasma without any essential change in amplitude and shape. 相似文献
103.
This Letter talks about the dynamics of dark optical solitons that are governed by the nonlinear Schrödinger's equation with power law nonlinearity. The solitons are considered in presence of linear attenuation, third order dispersion and self-steepening terms, all with time-dependent coefficients. The solitary wave ansatz is used to carry out the integration and an exact soliton solution is obtained. It is only necessary that these time-dependent coefficients are Riemann integrable. 相似文献
104.
Using the coherent density approach, we study the dark incoherent soliton splitting in biased photorefractive-photovoltaic crystals. We show that when the full width half maximum (FWHM) of the optical beam’s intensity is increased, the odd incoherent dark beam splits into an odd-number sequence of multiple dark stripes, whereas the even incoherent dark beam splits into an even-number sequence of multiple dark stripes. We find that when more incoherent solitons are generated, the separations between adjacent dark stripes become smaller and the stripes far away from the center become less visible and that for a given physical system and for a given splitting, the separations between adjacent dark stripes decrease with an increase in the intensity FWHM of the optical beam. On the other hand, the dark incoherent soliton splitting in biased photorefractive-photovoltaic crystals is the dark incoherent screening soliton splitting when the bulk photovoltaic effect is neglectable and the dark incoherent closed- and open-circuit photovoltaic soliton splitting when the external bias field is absent. 相似文献
105.
Propagation properties of bright and dark incoherent beams are numerically studied in photovoltaic-photorefractive crystal by using coherent density approach for the first time. Numerical simulations not only exhibit that bright incoherent photovoltaic quasi-soliton, grey-like incoherent photovoltaic soliton, incoherent soliton doublet and triplet can be established under proper conditions, but also display that the spatial coherence properties of these incoherent beams can be significantly affected during propagation by the photovoltaic field. 相似文献
106.
The proton radioactivity hMf-lives of spherical proton emitters are calculated by the cluster model with the con- tribution of a centrifugal potential barrier considered separately. The results are compared with the experimental data and other theoretical data, and good agreement is found for most nuclei. In addition, two formulae are pro- posed for the proton decay half-life of spherical proton emitters through the least squares fit to the experimental data available, and could reproduce the experimental half-lives successfully. 相似文献
107.
W. Urban M. Saha Sarkar S. Sarkar T. Rzaca-Urban J. L. Durell A. G. Smith J. A. Genevey J. A. Pinston G. S. Simpson I. Ahmad 《The European Physical Journal A - Hadrons and Nuclei》2006,27(3):257-262
The 136I nucleus, populated in the spontaneous fission of 248Cm, was studied by means of prompt γ-ray spectroscopy using the EUROGAM2 array. The observation in this work of the 42.6keV
prompt-γ, M1 + E2 transition de-exciting the 7- level in 136I indicates that this level, interpreted as the
configuration, does not correspond to the T = 47s, β-decaying isomer in 136I. The isomer is placed 42.6keV below the 7- level. It has spin 6- and is interpreted as the
configuration. This and other members of both multiplets can be reproduced properly only if one assumes that the πd5/2 orbital in 136I is located 400keV lower than in 133Sb. Possible mechanisms causing this effect are discussed. 相似文献
108.
Spatial Splitting and Intensity Suppression of Four-Wave Mixing in V-Type Three-Level Atomic System 下载免费PDF全文
We illustrate our experimental observation of coexisting the controllable spatial splitting and intensity suppression of four-wave mixing (FWM) beam in a V-type three-level atomic system. The peak number and separation distance of the FWM beam are controlled by the intensities and frequencies of the laser beams, as well as atomic density. 相似文献
109.
MA Fei ZHOU Xiao-Hong ZHENG Yong XU Shu-Wei XIE Yuan-Xiang CHEN Liang ZHANG Yu-Hu LI Zhan-Kui QIANG Yun-Hua LEI Xiang-Guo GUO Ying-Xiang GUO Song DING Bing WANG Hai-Xia LI Guang-Shun ZHOU Hou-Bing 《中国物理快报》2010,27(6):59-61
The β-delayed proton decay of 147Er is studied experimentally using the 58 Ni+92Mo reaction at a beam energy of 383 MeV. Based on a He-jet apparatus coupled with a tape transport system, the β-delayed proton radioactivities both from the vδl/2 ground state and the vh11/2 isomer in 147 Er are identified by proton-7 coincidence measurements. By analyzing the time distribution of the 4+ → 2+-γ transition in the grand-daughter nucleus 146Dy, a half-life of 1.6 ± 0.2s is determined for the Vh11/2 isomer in 147 Er. The half-life for the ground state of 147Er is estimated to be 3.2±1.2 s. 相似文献
110.
J. Khuyagbaatar S. Hofmann F. P. Heßberger D. Ackermann H. G. Burkhard S. Heinz B. Kindler I. Kojouharov B. Lommel R. Mann J. Maurer K. Nishio Yu. Novikov 《The European Physical Journal A - Hadrons and Nuclei》2008,37(2):177-183
Spontaneous fission of neutron-deficient fermium isotopes (N ≤ 144) was investigated. The nuclei were produced in fusion-evaporation reactions of 40Ar beams with 204,206–208Pb targets. Excitation functions of the two-and three-neutron evaporation channels were measured. The new isotope 241Fm was identified, and its decay properties were determined. A previously made assignment of a 0.8 ms spontaneous-fission activity to the isotope 242Fm could not be confirmed. Isomeric states were not observed in any of the investigated isotopes. The experiments were performed at the velocity filter SHIP of GSI in Darmstadt. 相似文献