Damping Solitary Wave in a Three-Dimensional Rectangular Geometry Plasma

The solitary waves of a viscous plasma confined in a cuboid under the three types of boundary condition are theoretically investigated in the present paper.By introducing a threedimensional rectangular geometry and employing the reductive perturbation theory,a quasi-Kd V equation is derived in the viscous plasma and a damping solitary wave is obtained.It is found that the damping rate increases as the viscosity coefficient increases,or increases as the length and width of the rectangle decrease,for all kinds of boundary condition.Nevertheless,the magnitude of the damping rate is dominated by the types of boundary condition.We thus observe the existence of a damping solitary wave from the fact that its amplitude disappears rapidly for a → 0and b → 0,or ν→ ＋∞.

Dust Acoustic Shock Waves with Non-Thermal and Vortex-Like Ions in Dusty Plasma

A rigorous investigation is presented on the propagation characteristics of non-linear dust acoustic（DA）waves in an unmagnetized dusty plasma system containing non-thermal and vortex-like ions and Maxwellian electrons under the effect of a fluctuating charged dust fluid.The three-dimensional（3D）Burgers＇equation and a new form of a lower degree modified 3D Burgers＇equation with their analytical solutions are derived to study the features of shock waves in such plasmas.The effect of the population of non-thermal ions,the vortex-like ion parameter as well as the temperature ratios of ions and electrons on the evolution of shock waves in the presence of dust charge fluctuation is presented.This theoretical investigation might be effectively utilized to unveil the nature of many astrophysical plasma environments（Saturn＇s spokes etc.）where such plasmas are reported to have existed.

Effect of the Formation of CNTs on the Reduction of Ilmenite

The reduction process of ilmenite by hydrogen and methane under MPCVD was analyzed by XRD result. The reduction degree of ilmenite increased with adding methane, the case similar to reduction rate. The mechanism of reduction process changed with the increasement of methane flow because of the formation of carbon nanotubes （CNTs）. The morphology of reduced samples was observed by SEM, and it was found that CNTs played an important role in the fracture of ilmenite particles. The reduction kinetics showed that the reduction was rate-controlling for hydrogen, and diffusion-controlling when hydrogen mixed with high flow methane.