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The effects of the specific anapole interaction have been studied in detail. The study of the processes of electrically weak interaction of fermions and bosons at energy 10-14 TeV using the detector ATLAS (CERN) has revealed that the contributions of this interaction under such conditions may be comparable in value with the radiation corrections to the corresponding scattering cross sections.
A series of theoretical and experimental studies has been completed of nonresonance physical processes in multilayer liquid media of the type of eye biological tissues under the action of single pulses of high-intensity laser radiation of duration 10-8--1 s in the 400--11,000 nm range. On this basis the mathematical models of primary destruction of human retina and cornea as a result of irradiation have been developed. The results obtained have been used to work out "The Safety Standards and Rules for the Operation of Lasers", and have made it possible to create a number of ophthalmologic devices and several ophthalmologic complexes which are produced in Belarus and Russia.
By the method of resonance Raman scattering with time resolution £ 3 ps the ultrafast processes of photoexcitation dissipation in the nickel-octaethylporphyrin solution have been investigated for the first time. It has been shown that during the first 10 ps the processes of vibrational heating and structural-conformational changes dominate. Nonequilibrium distribution of the initial vibrational excitation with prevailing localization on the vibrations of the mode n4 has been discovered. It has been proved that the porphyrin macrocycle expansion occurs at the moment the excited electronic state (d,d) is populated, and the conformation transition from the ruffled to planar structure of the macrocycle takes about 10 ps. (In cooperation with the Institute of Molecular Sciences, Okazaki, Japan.)
A new passive laser shutter has been proposed, which is based on the phenomenon of total internal reflection at the transparent dielectric boundary with a strongly absorbing medium. The shutter provides automatic cutting from a solid laser monopulse of pulses with a shape close to rectangular with a duration changing smoothly from 1 to 30 ns.
A method has been developed for rapid determination of the 90Sr content in fresh nuclear fallout from the measured activity of the 89Sr radionuclide and the activity ratio of the radionuclides 103Ru and 106Ru.
An evolutionary algorithm for solving the nonstationary electrodynamic problem related to the prism excitation of a nonlinear waveguide by a limited beam has been proposed. The possibility of an explanation of the observed phenomena of bistability by the influence of heat nonlinearity was analyzed. Changes of reflection factors of the Gauss and step beams with the input power variation are build under different weights of the Kerr and heat nonlinearities. It has been determined that in the case of heat nonlinearity prevalence these dependencies can be of hysteresis type. Dynamic features of switching between stable states of the system are also studied.
Schemes of integrated optical sensors of physical parameters of media have been offered and fabricated, which principle of action is based on registrations of reflected light beam under the resonance excitation of optical waveguides. The problem of optimum choice of device parameters is solved and the concentration measurements of ammonia/moisture in atmosphere are executed.
Nonlinear optical features of anisotropic waveguiding layers made by the diffusion of the methyl-red azo-dye in the polymer were studied. High refraction and àbsorption nonlinearity of waveguides under the action of spreading red color controlled by weak additional short-wave irradiation has been discovered. It is shown that the kinetics of the process is determined by the mutual photoconversion of photochromic trans- and cis-isomers of the dye. The possibility of fabricating on the basis of these structures a completely optical switching waveguiding device has been also studied.
An exact solution of the closure problem for stochastic radiation transfer equation in M-component Markovian mixture with plane geometry is obtained. The results obtained can be used for the description of radiation transfer in the atmosphere, oceans and human tissues taking into account their stochastic structure.
Seven independent elements of the Mueller matrix of any nondepolarizing optical system are established. Fundamental relations for coupling of the rest elements of the Mueller matrix through independent ones are received. The results obtained allow one to develop simple methods of experimental determination of Mueller matrix's components for non-depolarizing optical systems based on the measuring independent elements only.
A method has been developed for amplitude modulation of light radiation on the basis of controlled multiple multibeam interference, which offers high modulation efficiency. In this method, increased modulation efficiency is achieved by using polarization filtering of parasitic light beams arising outside the interferometer and by phase synchronization of the beams coming into the interferometer. A condition has been derived for the phase synchronization of light beams in the interferometer, which allows the minimization of light losses and increase in light transmission of the whole optical system.
Crystallization regularities have been found in ion-implanted indium phosphide and gallium arsenide subjected to nanosecond laser heating. It is discovered that in case of nanosecond laser annealing of implanted binary semiconductor compounds, just as in elementary semiconductors, there occurs intermediate crystallization of amorphized implanted layer. Such annealing results only in insignificant broadening of the implanted impurity profile, which makes it possible to form shallow p-n-junctions in A3B5 compounds. The proposed model, which describes impurity distribution in laser-annealed indium phosphide and takes into account diffusion in liquid phase, shows good agreement with the experimental results.
A solution has been found to the problem of spreading of low-melting glass boundary (phosphosilicate glass (PSG) and borophosphatesilicate glass (BPSG)) in thermostimulated processes used for relief planarization of microelectronic structures. Analytical expressions have been derived which define functional relationship between the fusion angle, thermal treatment parameters and physical characteristics of the glasses. It is shown that the rate of glass heating is a critical factor in the fusion process. The investigation results are used in optimization of PSG and BPSG thermal treatment regimes employed in integrated circuit production technology.
Methods have been developed for making reproducible sensitive film elements of gas sensors based on oxides of Sn, Zr, Ti and Ta. It is found that the films obtained consist of higher oxides of the metals. Test structure of a microsensor has been worked out on the basis of perforated superthin substrates. The structure shows thermomechanical stability up to 850 °C. Prototypes of the devices with the sensitive layer made of tin dioxide offer high operational characteristics. Even the laboratory prototypes can reduce power consumption of sensors and increase their sensitivity by two or three times.
Methods have been proposed to minimize nonlinear signal distortions in magnetoelectric measurement channels. The methods are based on formation of discrete excitation signal and compensation of amplification instability and phase distortions in the magnetic-field feedback circuit. The investigations have resulted in creation of breadboards of magnetomeasuring channels for inclinometric systems (for determination of inclination and direction of drill-holes) with 0.02% error, sensitivity threshold for magnetic field of 1 nT, consumption current 25 mA. Also, power consumption of the channel has been reduced approximately 5-fold.
A number of silicon compiler methods are worked out which are oriented to CMOS technology of VLSI chips production. These methods transform high-level structural and functional descriptions of a VLSI chips into structural and symbolic layout ones represented in SOURCE files. The tools for building various layout styles are proposed: Programmable Logic Array, Read-Only Memory, Regular Metal-Oxide Semiconductor Structure, One-Dimensional Logic Array -- the Weinberger Matrix and Gate Matrix. Logic verification methods are worked out for these layout styles. The proposed tools are embodied in the form a silicon compiler named SCAS (Silicon Compiler of the Academy of Sciences of Belarus). The SCAS is designed to work in MS DOS configured as follows: an IBM-compatible computer and a hard disk with 20 Mb of space. The silicon compilation process is supported by cell libraries describing macroelements on functional, schematic and technological levels.
The theory of elasticity-ductility with translation of the loading surface by means of the procedures of inner inherited ductility is developed, describing the main effects of the environment memory while the processes of grading deformation programs. Relations proposed are considered to be prospected to improve the adequacy of mathematical modeling in plastic metal working because in existing modeling systems only the simplified theory of elasticity-ductility without consideration of the effect of inherited ductility are used.
Methods and algorithms to determine parameters of the individual standard of a construction of spatial object under the generalized standard of a class and generalized standard of the class under a given set of its representatives are developed. Objects and standards are represented by point models, the object models can be underdetermined. The methods are based on optimizing affine transformations. Special decomposition technique for solving arising optimization problems is proposed. The project is intended for systems of diagnostics of anomalies of spatial objects with beforehand not known laws of their construction and takes into account peculiarities of the problem. The results are used in system of computer-aided diagnostics and treatment planning of malocclusions.
It is proved that traveling waves in physically different media have capability to transfer the mass of this media. It is described that such capability is used for different functions in nature (wave methods of locomotion, peristaltic), engineering (wave mechanisms and machines), geophysics (traveling tidal waves, atmosphere motions, ocean currents generation, motions in solid and liquid Earth spheres). The quantitative relations for wave mass transfer were received, devices and instruments for modeling and demonstration of traveling wave capabilities were designed and produced. The main wave regularities in geophysics media give possibility to make a nontraditional explanations of some geophysics phenomena (mechanism of plate tectonics, earthquake generation, ocean currents generation, origin of Earth magnetic field).
A computer model of speaker-independent continuous speech recognition based on a new method of optimal dynamic time warping between the set of acoustical features of place and manner articulation of pronounced words and there patterns was developed. The suggested method gives not only the possibility of optimal matching of non-linear time-warped words but also to define the optimal start and end points of the pronounced word in running speech signal. In a frame of the model a new speaker-independent method of words training using small number of words-samples was also used. The model is designed for the application in a new generation of man-machine voice-controlled systems
A method for formation and recording of the high-performance images, based on a combination of procedures of multichannel driving of recording effects, digital correction of local dozes of effect on a carrier in view of the individual characteristics of discrete emitters, multiline case scanning of a working area and synchronous formation of a raster-type image description is proposed and realized. On the basis of this technique a parametrical series of imagesetting devices, ensuring computer output of two-level and half-tone images on hard carriers designed for direct-to-press computerized systems is developed.
Some sufficient stability and asymptotic stability conditions are established for the discrete Volterra system of equations. For the linear-quadratic control problem for such systems the existence and uniqueness of optimal solution is proved. Moreover, optimal control is presented by feedback control form frequency domain.
The irregularity characteristic is constructed of general linear system determining the complete class of perturbations keeping lower Perron indexes.
Monotone, conservative schemes of the second order of local approximation are constructed for multi-dimensional Poisson equation on arbitrary rectangle nonuniform grid. Stability of the scheme with respect to boundary conditions and right sides is proved and a priory estimates in grid norms w12, w22 and C are obtained. (In cooperation with the Institute of Mathematical Simulation of the Russian Academy of Sciences, Russia.)
A method for constructing optimal positional solutions for general linear impulse control systems is justified to stabilize by bounded feedbacks.
A method of the localization of arcs for the graph models of two-level parallel algorithms is developed.
Manifestation of various origin anisotropy in lasers is studied in detail. Highly effective intracavity methods of control of generation parameters have been proposed and realized on this base. Principles are created and methods are developed of polarization laser spectroscopy. These methods are widely applying for measurement of spectroscopic constants of substance and for investigation of spectral lines structure and of anisotropic media properties.
It has been established that the formation of a composition and charge state of decaying laser-produced plasma in the air occurs in result of the competition between the three-body electron-ion recombination and gas-dynamic expansion processes during first several microseconds after the action of a laser pulse (10 ns) on the target surface and of prevailing influence of the exothermic reactions (oxidation) at the subsequent stage (tens of microseconds).
It is established that the temperature of plasma's neutral component of high frequency capacitative discharge in laser CO2+N2+He gas mixtures is independent on frequency of discharge excitation in the range of reduced electric field strength E/N=(2--10)·10-16 V·cm2. It is also shown that the considerable discharge non-homogeneity determines the distinction of dissipation mechanisms of contributed into discharge energy in different spatial zones of the discharge. The plasma's neutral component heating in the center of discharge chamber is mainly due to processes of V-T-relaxation of vibrationally excited nitrogen and carbon dioxide molecules in the ground electronic state while in the sheath vicinity deactivation of A3S metastable states of nitrogen is the main factor in the plasma heating equally with the V-T-relaxation.
Method and technology of organic molecules, organic and semiconductor crystals exciting by powerful high-energy nanosecond e-beam were elaborated, and excitation cross sections of organic molecules are measured. Laser action in blue spectral range and their characteristics under electron excitation were studied in ZnSe layers grown by method of organic vapor phase epitaxy on AsGa plate. It was established that generation arised as on resonator layer chips as with full internal reflection from epitaxial layer borders. (In cooperation with the Institute of Semiconductor Technics, Aachen, Germany.)
A sol-gel technology of Ln-containing silica glasses synthesis of high optical quality by means of straight transition "sol-gel-glass" is developed. The ability is established of quadruply charged cerium to form complex centers, in which the Ce3+, Sm3+, Eu3+ ions are characterized by high local symmetry and effective sensitization of their luminescence by means of excitation transfer from photoreducted (Ce4+)- ions. The results obtained open new possibilities for creation of activated materials with phototropic properties. (In cooperation with the Fr.Skaryna Gomel State University.)
The Pb0.2Sn0.8Te single-crystal films with high carrier mobility and weak temperature dependence of their concentration have been grown on BaF2 substrates by the molecular beam epitaxy method. These films are perspective for application in low temperature galvanomagnetic sensors.
The phase equilibrium diagram for the Zn-Cd-P-As system is plotted. The field of existence of 4-component solid solutions on the basis of ZnP2, ZnAs2, CdP2, CdAs2 and CdP4 compounds is established for the first time. These materials are perspective for preparation of new semiconductor elements with a broad region of smooth variations of their properties.
An enhanced radiation hardness of the Si/Ge superlattices as compared to bulk silicon crystals has been found and related to the capture and recombination of mobile radiation defects at the layer interface.
The TlGaSe2 politype modification with shift of incommensurate-commensurate phase transition temperature caused by stacking faults have been detected for the first time by means of X-ray method.
New metastable modifications of manganese antimonide Mn2Sb and solid solutions Mn2-xFexSb having hexagonal crystal structure and magnetic ordering below 100 Ê have been obtained by the high pressure and temperature technique.
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The polarization and diffraction properties of the Bessel and Gauss light beams in crystals with a complex anisotropy are investigated. An opportunity is shown to design and create optical interconnection devices based on electrooptical control of the form of light beams.
A comparison of the transfer rate characteristics of optical communication channels for two different coding methods is performed: (i) modulation of positioning pulse with binary amplitude representation and (ii) amplitude coding. It is shown that in optical channels with the pulse-positioning alphabets, which provide low power expenses, the maximum rate of a fault-free information transfer is almost two times lower than that for the usual binary amplitude coding. Under condition of a negligibly small thermal noise of the receiver the rate of information transfer in optical communication channels with amplitude coding is high and can be only several times lower than the limiting throughput, which is due to the quantum-statistical properties of information carriers.
Source: "Main Results of Fundamental Research. 1996--1997". Eds. F.A.Lakhvich and N.N.Kostyukovich. National Academy of Sciences of Belarus, Minsk, 1998.
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