Home – Home – Jornals – Advanced Search

The mechanism of occurrence of sensitivity of microbolometer detector arrays based on vanadium oxide to terahertz radiation are analyzed. Experimental data are given showing the possibility of increasing the sensitivity of microbolometer detectors in the terahertz range by using an additional thin metal absorbing layer applied on the microbolometer membrane. A polarization dependence of the sensitivity of microbolometers in the terahertz and far infrared spectral ranges is found. It is shown that the sensitivity of microbolometers in the terahertz range is due to the absorption of radiation in the narrow metal runs placed on the support legs of the microbolometers and playing the role of an ohmic contact between the heat-sensitive layer and the processing curcuit.

Thin films obtained by centrifugation of blood serum of healthy people and patients with diffuse pathology of liver with different degrees of fibrosis are studied by means of spectroscopic ellipsometry. The physical properties of the films are found to depend on the bio-organic composition of blood serum, which, in turn, is determined by pathological processes proceeding at different degrees of liver fibrosis. Correlations between the bio-chemical parameters of blood serum and ellipsometric data are obtained. Pilot ellipsometric experiments on studying blood serum with observations of the plasmon resonance of patients with intestinal tract tumors are performed. A persistent specific interaction between antigens of patient's blood serum and SD24 monoclonal antibodies is found, which alters the position of the surface plasmon resonance. It is demonstrated that ellipsometry is a high-sensitivity nondestructive inexpensive express method of screening, i.e., preliminary diagnostics of disease stages for patients with pathologies of internals.

This paper describes an automated photoelectromagnetic set of instrumental and methodological tools designed to determine the electrical and recombination-diffusion parameters of charge carriers in epitaxial films and p-type mercury-cadmium-tellurium film structures with thickness comparable to the diffusion length of minority carriers. The complex includes the following methods: the Hall effect, magnetoresistance, the photomagnetic effect, and photoconductivity in a magnetic field for the Faraday and Voigt geometries. The following parameters were determined: equilibrium concentration, the mobility of majority and minority charge carriers (holes and electrons, respectively), the bulk lifetimes electrons and holes, surface recombination velocities on the free boundary of the film and the interface with the substrate.

An approximate method is developed for calculating the systematic and root-mean-square errors of the algorithm for estimating the anisotropic texture orientation on the basis of a gradient structure tensor. It is demonstrated that the method is highly accurate and computationally efficient, as compared to the method of computer modeling.

The notion of the Catalan numerical sequence is extended. Problems leading to generalized Catalan numbers are formulated and solved.

A solution of the problem of reconstructing the coordinates of a 3D-object from parallel projections in the form of its shadows is considered. It is shown that the conjugate points required for the reconstruction are located on the extreme line which passes through these projections the line. An algorithm is developed to detect conjugate points lying on the contours of shadows.

This paper considers the problem of obtaining the shape of spatial group point objects using the principal component method, which allows one to find a rotation-invariant representation of quaternion signals defining spatial group point objects. An advantage of this approach is the possibility of estimating rotation parameters in the absence of information on the numbering of points in the object.

Devices used for testing of infrared imaging systems are briefly reviewed. Popular methods of dynamic scene generation in the infrared range, which are used in testing systems, and their basic parameters are presented. Approximate schemes of constructing such testing systems, based on arrays of controlled micromirrors and emitting elements, are described. A comparative analysis of the most popular testing systems is performed.

This paper presents a mathematical description of the dynamic properties of nonlinear random physical signals, i.e., signals modeled by random functions of time (processes and sequences) with a nonlinear the regression. It is shown that traditional methods of correlation and spectral analyses are poorly suitable or not at all for representing their dynamics. As an alternative, the paper gives a description and analysis of such signals using time (concorrelation functions) and frequency (conspectral density) concors. They exist for all random functions and the modulus of their values re invariant to any instantaneous one-to-one monotonic transformations of signals.

A model of parallel queueing of requests is developed for a queueing system consisting of two units with an unlimited number of servers in each unit and with retrial queueing in the units. An analytic expression is obtained for the generating function of the multi-dimensional state probability distribution of the random vector which characterizes the number of requests in each unit and the number of repeated calls to each unit in a nonstationary mode.