It has been shown that in jet processes in quantum chromodynamics the formation of squeezed gluon states is possible.
The general complete sets of commutation relations for the elements of quantum matrices of arbitrary dimensions have been obtained, and simple (finite) rules of the composition of parameters for various four-parametric quantum groups have been introduced.
The existence of the previously unknown phenomenon -- the diffusion orientation of dye molecules in solutions at their excitation by linearly polarized light -- has been substantiated. The effect consists in spatial alignment of molecules in the direction determined by the electric vector of the exciting light. It appears in those cases where the rotational diffusion rate of a dye molecule in the ground and excited states is different because of the establishment in one of these states of hydrogen bonds with the surrounding solvent molecules.
Optical methods have been elaborated for diagnosing the multilayer structures modelling human organs (e.g. liver, lungs, bony tissue) and formations (e.g. oncological tumors, hematomas) lying at different depths in the muscular tissue.
The formation of the periodic structure in thin films of titanium glasses during the process of their crystallization by scanning laser beam because of periodic thermal instability of phase boundary of the crystallization has been discovered.
A precision method for measuring the complex propagation constants of planar optical waveguide modes has been developed.
An extensive operator variety of nonlinear algorithms for restoration of optical images is received. A method for selection of optimal algorithm from this variety based on the minimum of misinterpreted recognition is suggested. The results obtained permit to increase an efficiency of systems for optical-electronic and digital processing of information.
A study was made of the properties of edge photoluminescence in layered GaAs-structures. As a result of numerical simulation a relation of spectral characteristics and luminescence quantum yield with the parameters of layers and interfaces has been established. On this basis the methods for performing non-destructive diagnostics of structures and predicting noise characteristics of superhigh frequency GaAs field-effect transistors have been developed.
The problem of matching planar strip dielectric waveguides with fiber optic light guides has been solved, and the architecture of a multichannel fiber optic storage device ensuring increased information storage capacity owing to use of two-channel synchronization has been developed.
The correlation function and radiation amplification increment in the case of stimulated scattering (SS) on the Rayleigh line wing in the isotropic phase of nematic liquid crystals have been calculated. It is shown that the characteristic longitudinal space scale on which the SS is developed and the value of amplification increment depend on the relation between the pumping power and the critical self-focusing power, while the Stokes signal correlation function and the amplification constant diverge as the phase transition point is approached.
Totality of methods for constructing approximate solutions of mathematical optimization problems is developed. The methods are based on using combinatorial properties of the problems. An approach to analyzing stability of approximate solutions under the problem' initial data perturbation is suggested, and methods for calculating stability radius of -approximate solutions are developed.
The conversion algorithms 'text-to-speech' and 'speech-to-text' based on a new microwave method of speech signals representation are proposed. Based on the method, the program realization of speech synthesizer on some Slavonic languages is developed which is putting into practice on a number of institutions of Belarus and CIS. The project 'Microwave speech-to-text recognizer' presented to the International competition of Hewlett Packard Co. on image recognition has received the main prize.
The complex of coordinated algorithms of the functional-logical design of logical control systems in modern technological basis is worked out. It solves the problems of development, simulation and verification of logical control algorithms, transformation them into automata models and Boolean functions systems, design of optimized logical nets in the large scale integration basis of various levels. These problems are combinatorially reduced to discrete mathematics problems which are formulated in terms of Boolean functions, finite predicates, automata, relations, graphs, etc. The complex is realized in the framework of CAD system.
A description of all unramified central simple algebras of exponent two over function fields of p-adic elliptic curves is obtained.
For two-dimensional difference-differential systems the controllability criteria are proved, the equivalence between controllability property and solvability of appointment spectral problem is established, and, as a consequence, the conditions of stability are obtained. Two-sided estimates for Liapunov's characteristical indices of linear systems with exponentially decreasing perturbations are constructed.
For an arbitrary vector lattice, distributions of lattice points with respect to level sets of a convex polyhedron are described. In particular, for integer linear programming problems (ILPP), a description of feasible solution orderings is obtained. The description delivers a new complexity characteristic of the class of ILPP as a whole.
The direct measurements of time decay of the optically induced anisotropy for complex molecules in the gas phase were performed using femtosecond laser pulses. Two stages of the anisotropy relaxation have been registered: the initial anisotropy decays practically to zero during a time of several picoseconds and, at longer time, the anisotropy increases towards the steady-state value.
Based on the fluorescent measurements of the dynamics of densities of target material atoms, ions and oxide molecules in the decaying laser-produced plasma, the efficiency of the oxidation reaction and recombination process in dependence on target irradiation conditions has been elucidated.
The luminescence with the maximum in the range of 900 nm under excitation in the F-band of color center absorption of LiF crystals was detected for the first time. The results obtained show the complex character of the F-band in investigated crystals and allow one to apply preliminary the observed luminescence to the luminescence of the single vacancy neutral color centers.
The oxygen quenching of the fluorescence of organic molecules with different singlet-triplet splitting (S1--T1) in various solvents at different temperatures has been investigated by the methods of pulses fluorometry and kinetic spectroscopy. It is shown that the fluorescence quenching which involves energy transfer to oxygen occurs at the distance 10--12 Ao coincident with prediction of the theory for exchange interaction. On the other hand, the fluorescence quenching of molecules in which exchange transfer is not possible by energy factor takes place at the distance 6--7 Ao and to be concerned with removal of spin prohibition in the 'collisional complex' molecule of fluorofor with oxygen.
A theoretical model is proposed for superconductivity of high temperature superconducting (HTSC) compounds containing one-dimensional sublattice of interlayered oxygen atoms which are under conditions of asymmetric double well potential. The participation of the sublattice vibration in pairing of electrons is shown to lead to high temperatures of superconducting transitions Tc. Within the scope of the model both the high values of Tc and the anomalies in thermodynamic and kinetic characteristics of YBa2Cu3O7-xcompounds (x=0--1) have been interpreted for the first time. The data obtained allow one to predict the ways of raising the temperature of superconducting transition of HTSC materials.
The fundamentals of metal-organic synthesis of superconducting composites, representing bundled yttrium-containing HTSC reinforced thin fibers of metal oxide ceramics (e.g. ZrO2 -- Y2O3), have been developed. (In cooperation with the Belarusian State University.)
It is established that the viscosity destruction limit and ceramics hardness of Si3N4 can be raised significantly using definite types of activating agents of thermal sintering under high pressure (nitrides and borides of transition metals). The mechanism of interaction between high pressure induced crystal lattice defects and impurity atoms underlies this ceramics reinforcement.
A model of dynamics of coniferous forests in Belarus has been created, covering such effects as trees' growing and dying, photosynthesis, initial location of trees, etc. The experiments have been conducted proving the workability of the model. (With the participation of the Central Botanical Gardens of ASB.)
A tool has been created to carry out a unified description and evaluation of the complexity of a self-contained, integrated and regressive program testing for any basic criterion of a structural module testing. It allows one to control the structural testing and evaluate the quality of programs more effectively with the purpose of improving their reliability and safety. The principle possibility has been proved and the constructive methods suggested to implement testing, allowing to obtain a preset level of program testability over the linear time.
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The process of the many-beam laser-radiation formation (in particular, a laser beams with uniform amplitude profile) is investigated. A scheme of the optical resonator is proposed, in which the field with uniform profile can be obtained under the conditions of transverse modes locking and in-phase supermode selection.
The autowave processes in spatially extended optically bistable thin layers have been investigated. On the basis of the switching waves propagation regularities the method has been proposed for shifting binary optical information along the plane of such layers in transverse direction that does not coincide with the direction of light beams carrying the information. This has allowed to carry out and realize a multifunctional all-optical shift register. The possibility has been demonstrated to perform the modes of shifting, storing, parallel and serial recording, reading and converting the two-dimensional binary information arrays directly in the plane of matrix of bistable optical elements.
The effect of generation spectrum broadening has been discovered and theoretically described for quasi-stationary regime of a new type of color-centre lasers with flash-lamp pumping. The observed effect is shown to result from a spatially non-uniform depletion of the inverse population of the active medium that takes place in the field of the cavity standing waves. The high-efficiency laser devices for near-infrared spectroscopy has been carried out.
A considerable optical nonlinearity in the band-edge region has been observed in the A3B5-compounds doped by the donor impurities to level > 1018 cm-3. The theoretical model of this nonlinearity has been developed taking into account the light-induced electrooptical effect which is due to the spatial separation of the photogenerated carriers (the carrier transport).
Source: "Main Results of Fundamental Research.1992--1993". Eds. A.M.Goncharenko and N.N.Kostyukovich. Academy of Sciences of Belarus, Minsk, 1994
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