Аннотация.Данная работа посвящена экспериментальному исследованию процессов внутри вихревой камеры (завихрителя) в трубе Ранка бесконтактными методами.Была использована вихревая труба, состоящая из двухщелевого завихрителя, рабочего канала с квадратным сечением, радиального диффузора на горячем выходе и выходным отверстием на холодном выходе.Для возможности оптической диагностики вихревая камера (завихритель) была оснащена оптическими окнами.Измерения скорости были проведены при помощи лазерного доплеровского анемометра.Поток засеивался частицами дыма.С помощью измерений методом лазерной доплеровской анемометрии были получены новые

Аннотация.В рамках задачи развития методов фазовой доплеровской анемометрии разработан метод исследования структуры интерференционной картины, образованной полупроводниковым лазерным доплеровским анемометром с дифференциальной оптической схемой и модуляцией 80 МГц.Описаны основные аппаратные модули используемых лазерных доплеровских анемометров «ЛАД-080».Для исследования интерференционной картины был создан стенд из двух лазерных доплеровских анемометров и мишени.Лазерные анемометры модер-

Photoconducting polymeric composites (PPCs) containing nanosized organic or inorganic dopants (dyes and their aggregates, nanoparticles of inorganic semiconductors) are already employed as photoactive media in OLEDs, in photoelectric solar energy converters, in optoelectronic elements, and in electrography and holography. The final application is the subject of this chapter. The basic requirements of holographic recording media (HRM) for the photothermoplastic (PTP) recording technique are considered. Features of the PTP recoding are described and the main demands to HRM are formulated: low electric conductivity, high photoconductivity at the light wavelength of the used laser, good film-forming, and optical and thermoplastic properties. The mechanisms of PPC photoconductivity are studied, including photogeneration, recombination, transport, and capture of nonequilibrium charge carriers. These mechanisms are particular to the organic and inorganic disordered nanomaterials with photosemiconducting properties and differ from the mechanisms in crystal materials due to the absence of long- and short-distance orders in the disordered nanomaterials. Possibilities for the development of new polymeric bases for PPC are discussed to provide a realization of the requirements for HRM. A comparison of the photophysical and information properties of HRM based on cooligomers with linear and radial structure is fulfilled similarly to investigations into the influence of nanoparticle size on the photophysical properties of semiconductor materials. The potentials for the improvement of the information characteristics of HRM is considered with concrete examples. "Wet" development of holograms is not required in the PTP holographic recording technique. Thus, this technique can be used not only in visual holography, but mainly, and more effectively, in holographic interferometry for nondestructive quality control, for detection of the residual stresses in metallic units, and for measurements of refractive index, etc. Concrete examples of HRM and devices for their application are described. This information is not only of scientific interest for widening knowledge about the photo processes in PPC, but is also useful for practical applications of photosemiconducting nanomaterials for quality control of the means of production and products, for prevention breakage, crashes, and catastrophes.

We have numerically investigated nonlinear nonstationary velocity and pressure fields in a viscous incompressible fluid near an oscillating absolutely rigid plate of an infinitely small thickness and a limited length in the direction of oscillations. It is shown that the limitation imposed on the plate size along the direction of its oscillations leads to nonlinearity of the problem even for a small amplitude of surface oscillations of the plate. We have analyzed the velocity and pressure fields for large amplitudes of plate oscillations. The emergence of displacement flows during oscillations of an infinitely thin plate of a finite length is explained. The mechanism of formation of instantaneous vortex motions in the viscous fluid is investigated.

As part of the work on eliminating the nuclear legacy temporary storage facilities for high-level solid wastes were opened, radiometric inspection of the wastes was performed, wastes were sorted, control rods of ship reactors were identified in the wastes and removed, and spectrometric determination of the induced activity in each rod was made. Forty-four rods with activity totaling 1.35·1013 Bq were packaged and shipped to a long-term storage site. The activity distribution was determined from samples and will be taken into account in planning subsequent work on the handling of such wastes and picking the most appropriate type of packaging. The work was performed using remote-control machines in compliance with the standards and regulations for the radiation safety of personnel.

Abstract Based on polymers with the addition of azo dyes as chromophores and azopolymers with the same covalently linked chromophores, recording media for polarization holography are created and their properties are studied when recording holograms of a plane wave front with parallel and perpendicular polarization of recording rays. It is found that the diffraction efficiency and the storage time of holograms are much longer in recording media with films of azo polymers in comparison with polymeric solid solutions of azo dyes. In the latter case, the energy of light is spent only for the trans – cis isomerization of azo dye molecules during exposure of holograms and the polymer chains do not undergo deformation with the formation of a surface relief in the polymer film. Therefore, it is preferable to use recording media based on solid solutions of azo dyes in dynamic polarization holography.

The numerical study of nonlinear non-stationary velocity and pressure fields close to an absolutely rigid plate oscillating in incompressible viscous fluid along its length was performed. The plate had an infinitesimal thickness and finite length. The study showed that limiting the length of the plate leads to the problem non-linearity, which appears even with a small amplitude of the plate surface oscillations. We also studied the velocity and pressure fields with large amplitudes of the plate surface oscillations. The arising of the plug flows during the oscillations of the plate of infinitesimal thickness and finite length was explained in terms of viscous waves. The instant vortex motion formation mechanism in viscous fluid was uncovered.

AbstractRecording media for polarization holography have been created on the basis of 4-((2-bromo-4-nitrophenyl)diazenyl)phenyl methacrylate copolymers, and the properties during that they manifest during recording of holograms of a plane wavefront have been studied. It has been found that the hologram recording rate at room temperature is the same for the perpendicular and parallel polarization of recording rays and the hologram relaxation rate is higher in the case of perpendicular polarization orientation of recording rays. It has been shown that the diffraction efficiency of holograms does not exhibit a monotonic relation with the film softening temperature.

The basic principles of nonlinear ion-acoustic waves formation in weakly ionized gas subjected to the shock wave of neutral gas were investigated by the numerical and analytical methods. The ion-acoustic approximation were employed to describe the plasma component of charged gas [1]. Within a such approach the ion-acoustic waves arise via the collisions of charges with the neutral particles only. For numerical simulation the initial and approximate boundary conditions for non-stationary problem are determined in assumption that the solution of runaway wave type can be found [2]. The strong anomalous nonlinear effects appear in this case. The competitive action of nonlinearity, dispersion and dissipation at the formation of specific plasma "condensations" and "rarefactions" is shown [2]. In narrow range of the shock wave velocities the anomalous relaxation of plasma oscillations occurs behind the front. It appears in the total ambipolar entrainment by the shock wave of charged components. This effect possibly results from the strong nonlinear resonant (in respect to the shock wave velocity) perturbation in the region ahead of front. Nonlinear perturbations of weakly ionized non-isothermal gas (Te Ti ≈ Tn) under the action of a strong stationary shock wave of the neutral component have been studied based on computer-aided calculations. The detected patterns reflect the most essential features of the additional mechanism of reduction of the intensity of a strong shock wave of the neutral component without energy release for heating the region ahead of the front. The reciprocal action of the charged components upon the neutral particles result in change of the structure and reduction of the intensity of the shock wave. In such a case, a paradoxical situation arises: low-ionized plasma (the nonperturbed state is meant) exerts a strong effect upon the neutral component and the reduction of the shock wave intensity. Laboratory experiment data to corroborate such influence are available [3].

The structure of twisted flow in a Ranque−Hilsch vortex tube is investigated experimentally by modeling gas flow with an incompressible fluid flow. The velocity field is measured with a laser Doppler anemometer in the entire volume of the vortex chamber. The streamline pattern, which gives a complete presentation of the flow structure in the Ranque−Hilsch tube, is plotted in the axial section of the chamber. The resulting streamline pattern can serve as a basis for explaining the physical mechanism of the Ranque effect.

Two self-similar modes of evolution of charged particles’ high-current beam are described analytically. The situation being considered falls within the field of nonneutral plasma electrodynamics. The process is considered in terms of the nonlinear 1D evolution of the charge density w(x, t) in the channel of a longdistance transmission line with nonlinearly distributed resistance R, capacitance C, and inductance L: R = R(w), C = C(w), and L = 0. It is shown that initially the front of w(x, t) accelerates and then slows down. The description of the process in the channel is based on the charge conservation law. An idealized “kinematic” approach is used according to which an equation in two unknowns (charge density and current density in the channel) can be reduced to an equation in one unknown w(x, t). A strongly nonlinear wave process is studied. A discontinuous solution w(x, t) is constructed with a zero boundary condition at infinity. Such a model description can apply only for revealing the main qualitative features of a complex process. Analytical expressions for the variation in the evolution of the front velocity and perturbed area length are derived. An interrelation between the nonlinearity parameter of the process and the amount of charge in the interelectrode gap is suggested based on the experimental data for the evolution of streamers.

The results of numerical simulation of the nonlinear evolution of an acoustic pulse propagating above an earthquake epicenter with preset energy parameters are presented. The interaction with charged plasma particles in the lower ionosphere is taken into account. The interaction between neutral and charged components is described by the diffusion mechanism of the disturbance of the density of charged ionospheric plasma components. The simulation was carried out for three values of earthquake magnitude M = 5; 6; and 7. It is ascertained that the numerical simulation results agree with analytical estimates made during the study of main regularities of seismic events that induce weak nonlinear effects in the atmosphere.

The problem of determining the nonstationary nonlinear velocity field of a viscous incompressible liquid excited by the surface of tangentially vibrating cylinder has been solved numerically in the 2D approximation. It has been shown that the vibrating solid surface generates 2D viscous waves and a displacement flow. The trajectories of propagation of viscous waves and their velocities have been determined. The interaction of a viscous wave with the displacement flow has been analyzed in the first approximation; as a result of this interaction, the velocity field can not only be suppressed with increasing distance from the surface, but also enhanced.

Обнаружено, что пленки полимерных композитов на основе поливинилового спирта с добавками ксантенового красителя обладают фотовольтаическими свойствами и фотовольтаический отклик мало изменяется при концентрации красителя более 10 мас. % относительно массы полимера. Фотовольтаический эффект связан с фотогенерацией носителей электрического заряда в агрегатах красителя и транспортом неравновесных носителей заряда между ними. Сделан вывод, что для уменьшения себестоимости фотоактивных сред для фотоэлектрических преобразователей возможно применение дешевых полимеров с малой концентрацией органических красителей.

The effect of a strong shock wave on a weakly ionized collisional plasma was studied. The structure of the ion-acoustic perturbation caused by the shock wave was numerically investigated. The effect of the nonlinearity, dispersion, and dissipation on the formation of an oscillating wave profile was shown. It is found that in some modes, an increase in the shock wave velocity leads to a sharp increase in the concentration of charged particles and a reduction in the number of perturbation maxima. This change of the flow structure can be preceded by the formation of localized regions with an increased degree of plasma ionization. It is shown that the presence of plasmoids can lead to a strong influence of charges on the neutral component.

It has been found that films of polymer composites based on polyvinyl alcohol doped with a xanthene dye possess photovoltaic properties, and the photovoltaic response varies little at the dye concentration greater than 10 wt % with respect to the weight of the polymer. The photovoltaic effect is due to photogeneration of charge carriers in the dye aggregates and transport of nonequilibrium charge carriers among them. It is concluded that, in order to reduce the production cost of photoactive media for photovoltaic cells, it is possible to use cheap polymers with a low concentration of organic dyes.

Pulse heating of high-current contacts is notable for the presence of considerable temperature gradients in the contact area, which cause the Thomson effect—the appearance of thermoelectric currents. The amount of this effect against conventional Joule heat release is quantitatively estimated. Pulse heating of electrical contacts is numerically simulated with the use of the Comsol program package. It is demonstrated that thermoelectric currents make a negligible contribution to heating in the case of copper contacts.

The proper axial rotation and right-handed helical orbital rotation of Earth are the simplest and persistent factors of chiral influence on the Earth. These types of motion are treated as basic to the selection of L-amino acids and D-sugars (homochirality) as 'building blocks' for constructing right-handed helical biomacromolecules. The role of agent for transfer of chiral influence of the factors mentioned above on the molecular level can be played by tides and wind waves. The rise and fall of the waves leads to formation of mainly right-handed helical water associates that favour the formation of right-handed helical biomolecules. Biological indications of the existence of such water associates are discussed.