Relations between fluid viscosity and attenuation, modulus or velocity dispersion in porous sandstone;

The viscosity coefficient of pore fluid in saturated sandstone has an obvious effect on theattenuation, modulus, and velocity dispersion in low frequency range.

To study the mechanism, we performed seismic numerical simulation of geological models with a hydrocarbon-bearing zone using the 2-D diffusive-viscous wave equation which can effectively model the characteristics of velocity dispersion and transform the seismic dat.

Then the effects of higher-order group-velocity dispersion (GVD) on SC generation in different fibers are analyzed and contrasted in details through simulation.

Futher more, self-similar pulses which are generated in fiber amplifiers with positive group-velocity dispersion, have become popular owing its the most attractive characteristic which the spectrum of self-similar pulse can be widened with a strict linear chirp across the whole duration of the amplified pulse.

Under the combined effects of group-velocity dispersion and self-phase modulation,the step Fourier method can be used to simulate the propagation of initial chirped Gaussian pulses inside fiber.

The effect of group velocity dispersion (GVD) on the focus was discussed.

Structure dispersion is primary when wave of input optical pulse is close to verge outside the stop-band of Fiber Bragg Gratings, optical pulse can come into being Bragg solitons by a careful control of self-phase modulation (SPM), cross-phase modulation (XPM) and group velocity dispersion (GVD).

The effects of group velocity dispersion, polarization mode dispersion and nonlinearity in fiber on the performance of wavelength division multiplexing system are analyzed in detail.

The properties of propagation of picoseconds optical soliton described by modified nonlinear Schr dinger equation with Kerr coefficient and group velocity dispersion distributing randomly in Dispersion-Shifted Fiber are studied by using symmetrical slit-step Fourier numerical method.

The results show that the broadening effects induced by the first order PMD are independent on group velocity dispersion (GVD) and chirp, which are different from the effects induced by the second order PMD.

Interactions between the SPM-induced Chirpand GVD-red Induced Chirp in a Singlemode Fiber;

Taken into account both second order dispersion and SPM in the abnormal-dispersion region of single-mode fibers, we obtained the expression of chirp induced by GVD and SPM.

On the basis of GVD and SPM, an analytic expression of chirp induced by the interactions of both SPM and GVD chirp was obtained, completely analyzing the relationship of chirp changes and dispersion length LD and nonlinear length LNL.