蛋白质分子的红外吸收的温度特征

考虑了Ａｍｉｄｅ－Ⅰ振子同肽群振动的光学声子相耦合，在该理论中研究了在蛋白质分子中的孤立子引起的红外吸收的反常红移和温度依赖关系。所得结果较好地吻合于实验值。从而也证实了蛋白质中确有孤立子激发的存在     

Lax pair, Bäcklund transformation and N-soliton-like solution for a variable-coefficient Gardner equation from nonlinear lattice, plasma physics and ocean dynamics with symbolic computation

In this paper, a generalized variable-coefficient Gardner equation arising in nonlinear lattice, plasma physics and ocean dynamics is investigated. With symbolic computation, the Lax pair and Bäcklund transformation are explicitly obtained when the coefficient functions obey the Painlevé-integrable conditions. Meanwhile, under the constraint conditions, two transformations from such an equation either to the constant-coefficient Gardner or modified Korteweg-de Vries (mKdV) equation are proposed. Via the two transformations, the investigations on the variable-coefficient Gardner equation can be based on the constant-coefficient ones. The N-soliton-like solution is presented and discussed through the figures for some sample solutions. It is shown in the discussions that the variable-coefficient Gardner equation possesses the right- and left-travelling soliton-like waves, which involve abundant temporally-inhomogeneous features.     

On the exact solutions of nonlinear diffusion-reaction equations with quadratic and cubic nonlinearities

Attempts have been made to look for the soliton content in the solutions of the recently studied nonlinear diffusion-reaction equations [R S Kaushal, J. Phys. 38, 3897 (2005)] involving quadratic or cubic nonlinearities in addition to the convective flux term which renders the system nonconservative and the corresponding Hamiltonian non-Hermitian.     

SOLITON SOLUTIONS OF A CLASS OF GENERALIZED NONLINEAR SCHRODINGER EQUATIONS

Soliton solutions of a class of generalized nonlinear evolution equations are discussed ana-lytically and numerically. This is done by using a travelling wave method to formulate one-soliton solution and the finite difference method to the numerical solutions and the interactions betweenthe solitons for the generalized nonlinear Sehrodinger equations. the characteristic behavior of thenonlinearity admintted in the system has been investigated and the soliton states of the system in thelimit when a→Oand a→∞ have been studled. The results presented show that the soliton phe-rtomenon is charaeteristics associated with the nonlinearities of the dynamical systems.     

Effect of the Aharonov-Bohm flux on the magnetic gap soliton in antiferromagnetic chain

Employing the double-sublattice, the coherent state ansatz, and the time-dependent variational principle, we have studied the effects of the Aharonov-Bohm flux on the soliton in one-dimensional antiferromagnetic chain. The results show that the Aharonov-Bohm flux have an effect on the peak, the width, the energy and the spatial configuration of the spin of the soliton.     

波分复用孤子通信系统容量研究

在波分复用(WDM)孤子通信系统中,不同信道的孤子由于载波频率不一样而会发生周期性的碰撞,碰撞将引起孤子到达接收端时间的移动,这个现象限制着邻近信道的最小频率间隔和可以被复用的最大频率范围,即决定了WDM孤子通信系统的最大通信容量。     

Soliton switching in twin-core fibers with gain and loss

Soliton propagation and switching in twin-core nonlinear fibers with gain and loss have been investigated based on a pair of coupled nonlinear Schr?dinger equations. We have found the fiber with equal amount of gain in both cores has the minimum ascending energy Δɛ of 1.5K, while the fiber with a certain amount of gain in one core and the same amount of loss in the other core has the minimum switching thresholdɛ _th of 2.05K. A new vector field is defined and its potential function is derived, which explains the switching behavior of the minimumɛ _th switch satisfactorily.     

Quantum noise limits to terabaud communications

From a general model of fiber optics, we investigate the physical limits of soliton-based terabaud communication systems. In particular we consider Raman and initial quantum noise effects which are often neglected in fiber communications. Simulations of the position diffusion in dark and bright solitons show that these effects become increasingly important at short pulse durations, even over kilometer-scale distances. We also obtain an approximate analytic theory in agreement with numerical simulations, which shows that the Raman effects exceed the Gordon-Haus jitter for sub-picosecond pulses.