Nonlinear waves and polarization in diffusive directed particle flow

We consider a system of two reaction-diffusion-advection equations describing the one dimensional directed motion of particles with superimposed diffusion and mutual alignment. For this system we show the existence of traveling wave solutions for weak diffusion by singular perturbation techniques and provide evidence for their existence also for stronger diffusion. We discuss different types of wave fronts and their composition to more complex patterns and illustrate their emergence from generic initial data by simulations. We also investigate the dependence of the wave velocities on the model parameters.Comment: 15 pages, 8 figure

General response function for interacting quantum liquids

Linearizing the appropriate kinetic equation we derive general response functions including selfconsistent mean fields or density functionals and collisional dissipative contributions. The latter ones are considered in relaxation time approximation conserving successively different balance equations. The effect of collisions is represented by correlation functions which are possible to calculate with the help of the finite temperature Lindhard RPA expression. The presented results are applicable to finite temperature response of interacting quantum systems if the quasiparticle or mean field energy is parameterized within Skyrme - type of functionals including density, current and energy dependencies which can be considered alternatively as density functionals. By this way we allow to share correlations between density functional and collisional dissipative contributions appropriate for the special treatment. We present results for collective modes like the plasmon in plasma systems and the giant resonance in nuclei. The collisions lead in general to an enhanced damping of collective modes. If the collision frequency is close to the frequency of the collective mode, resonance occurs and the collective mode is enhanced showing a collisional narrowing

Immatures of Parandra (Tavandra) longicollis Thomson, 1861 and comments on the larvae of Parandrinae (Coleoptera: Cerambycidae)

The last larval instar and pupa of Parandra (Tavandra) longicollis Thomson, 1861 are described and illustrated. The taxonomy and morphology of immatures of Parandrinae are discussed. A key to larvae and synopsis table to known immatures of Parandrinae are provided