Interaction of charged particle flows with plasmons in two-dimensional electron gas

The theory of interaction of charged particle beams with 2D electron gas, located in the field of the delta-like potential wallU(y) =U _oδ(y) has been developed. The kinetic equation for plasmons in 2D electron gas was obtained; the conditions of arising of their instability are given and the corresponding expressions for the increment of plasmons are found.     

Integral curvatures,oscillation and rotation of spatial curves around affine subspaces

The main result of the paper is an upper bound for the oscillation of spatial curves around geodesic subspaces of the ambient space in terms of the integral geodesic curvatures of the curves.     

Morphology of pores produced in <Emphasis Type="Italic">n</Emphasis>-Si {100} by etching in hydrofluoric acid solutions

Variations in the contours of pores produced in n-type silicon by electrochemical etching in hydrofluoric acid solutions are interpreted in terms of the mechanism underlying the chemical interaction of the etchant with silicon and the anisotropy of the etchant–silicon system. Mathematical expressions are proposed which describe the contours and limiting radial sizes of pores forming at the very beginning of the etching process (~10–15 s).     

Nonstationary robust systems: A generalization of the class of control systems

In this paper, robust mathematical models of real-life processes are discussed. Robustness testifies itself not only in the parametric uncertainty setup, but also because the parameters can be thought of as sufficiently arbitrary functions of the independent variables (so-called nonstationary robustness). Control systems can be considered as specific cases of this situation. Nonstationary robustness is studied for the Lotka-Volterra predator-prey model and its modification.     

Performance analysis of the recording system of nonlocal biomechanical signals

This study presents the performance analysis results of biotechnical system for recording nonlocalized biomechanical signals. The circuits for simulating the impact of the pressing force (applied to the body surface) on the input of signal transducer were considered both in the absence and in the presence of a supporting surface of transducer. The sensor design was shown to influence the reduction level of the impact of the pressing force applied to the body resulting in the specific effect on the transducer input. In addition, the effect of the sensitivity loss of the recording channel of nonlocal biomechanical signals on the reduction level was also evaluated.     

Gornotaezhnoe geophysical system

A geophysical system has been built on the territory of the Ussuriisk astrophysical observatory of the Far East Branch, Russian Academy of Sciences. It includes a laser deformograph intended to detect variations of deformations of the Earth’s crust with an accuracy of 0.3 nm in a frequency range of 0–1000 Hz and GPS millimeter-accuracy stations.