Interaction Between Two Charged-Hardcore Soft Particles

During two last decades, theories of soft-particles has been introduced and developed in order to describe the behavior of bacteria and virus which can be considered as the bio-colloid particles. Soft particles are assumed to be consist of a rigid core inside an ion-permeable shell. The outer layer is always negatively charged while the core can be neutral or charged. In this paper, we investigate the interaction between two identical soft-particles with charged core. We derived the analytic formula for the interaction energy in a compact form. We showed that this interaction energy involving a screened Coulomb-like interaction term with a distance-independent coefficient. The numerical calculations showed that the interaction energy has very small amplitude and exponentially decay on the distance between the soft particles. The results indicate that it is possible to measure this kind of interaction energy when the system is put into a salt solution with the concentration low enough.

Nonlinear Photo-Diffusion in Amorphous Chalcogenide Multilayers

Enhanced intermixing, induced by a laser beam, has been recently observed in amorphous Se/As2S3 and similar multilayers. We report a model, based on the concept of thermal spikes, which can consistently describe experimental observations. The concentration dependence of the light absorption properties causes the photo-stimulated diffusion to be non-linear even when a concentration independent coefficient of thermo-stimulated diffusion is assumed.

Some results on principal eigenvalues for periodic parabolic problems with weight

Let Ω ⊂ ℝN be a bounded domain. We study existence and uniqueness of principal eigenvalues for the Dirichlet periodic parabolic problem with weight Lu = λmu in Ω × ℝ when the independent coefficient of the differential operator L is not necessarily positive.

Generation of Defects and Strain by Ion Implantation in Ge (100) Single Crystals, and in Pseudomorphic GexSi1-x Films Grown on Si (100)

ABSTRACTWe have studied the damage and strain produced in Ge (100) single crystals by implantation of various doses of 300 keV 28Si ions at room temperature. The analyzing tools were x-ray double-crystal diffractometry, and MeV 4He channeling spectrometry. The damage induced by implantation produces positive strain in Ge (100). The maximum perpendicular strain and maximum defect concentration rise nonlinearly with increasing dose. These quantities are linearly related with a dose-independent coefficient of ∼ 0.013 for Ge (100) single crystals implanted at room temperature. The results are compared with those available for Si (100) self-implantation. We have also monitored the strain and defects generated in pseudomorphic Ge0.1Si0.9/Si (100) films induced by room temperature 28Si ion implantation. It is found that the relationship between the strain and defect concentration induced by ion implantation is no longer a simple linear one.