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Power Range of Photoneutrons from 209Bi at Е γmax = 12 MeV

Authors: Belyaev S. N., Klochkov M. A., Nechkin A. A., Sidorov V. I.

On a bunch of brake radiation of the betatron the power range of photoneutrons from 209Bi is measured. Measurements are executed by means of a scintillation spectrometer on the basis of a stilbene crystal with discrimination γ-radiations in an impulse form. The obtained data are compared with known of literature and analyzed on the basis of evaporation model.

Research of the Contact Pads Topology Influence on the Parameters Reproducibility of the Current Oscillations in Mesa-Planar Structures Based on Semi-Insulatinggallium Arsenide

Authors: Kozhevnikov I. O., Mikhailov A. I., Bratashov D. N.

Experimental results of research the influence of the electric field distribution between the pads of mesa-planar resistor structures based on semi-insulating n-GaAs are represented. These influence by changing pads topology (plane-parallel, flat-pointed, counterpointed and concave-pointed) was studied for the current oscillations parameters (the threshold voltage, frequency and amplitude of current oscillations) reproducibility increasing.

Microwave Photonic Crystals. New Application Areas

Authors: Usanov D. A., Mardanov M. K., Skripal A. V., Ponomarev D. V.

The theoretical and experimental justifications of the possibility to use the microwave photonic crystals for the creation of broadband loads have been presented. The possibility to simultaneously determine the thickness and the conductivity of nanometer semiconductor layered structures by use of the microwave photonic crystals has been shown. The possibility of electrical control of the microwave photonic crystals amplitude-frequency characteristic has been experimentally demonstrated.

Digital Speckle Photography with Correlation Processing of Spatial Spectrum of Specklegram for Determination of Micro Displacement of Scattering Object

Authors: Maksimova L. A., Ryabukho P. V., Mysina N. Y., Ryabukho V. P.

The method of digital speckle photography for determining of speckle pattern displacement with sub-pixel accuracy using correlation processing of summary spatial spectrum of speckle patterns is considered in this article. It is assumed that displacement of speckle pattern is caused by deformation or displacement of an object with a scattering surface. The method of phase shift of interference pattern in diffraction halo is proposed for expanding the lower limit of measuring range of speckle pattern displacement to subpixel values.

Self-mixing Interferometry of Distance at Wavelength Modulation of Semiconductor Laser

Authors: Astakhov E. I., Usanov D. A., Skripal A. V., Dobdin S. Y.

Theoretical description for method of distance measurement at alteration emission wavelength of semiconductor laser, operated in self-mixing regime, has been presented. The result of computer modeling of self-mixing signal at harmonic wavelength modulation of laser diode has been represented. Spectral harmonic selection of low-frequency spectrum of self-mixing signal for distance measurement has been theoretically substantiated.

Optical Clearing of Human Eye Sclera by Aqueous 30%-Glucose Solution

Authors: Bashkatov A. N., Genina E. A., Kochubey V. I., Kamenskikh T. G., Tuchin V. V.

In this work, optical clearing of human eye sclera in vitro under action of aqueous 30% glucose solution was studied. It was shown that diffusion of glucose in tissue results in significant decrease of light scattering, which manifests itself in both decreasing reflectance and increasing transmittance of the samples. At that, absorption coefficient does not change. Measurements were performed with spectrophotometer CARY-2415 in the spectral range from 400 to 800 nm by a standard method.

The Liquid Crystal Modulator on the Basis of the Waveguide Mode in the Twist Structure with the High Twist Angle

Authors: Simonenko G. V., Studentsov S. A., Ezhov V. A.

On the basis of the analysis of color characteristics of different LC display units the criterion for an assessment of an unchromaticity of black-and-white images is entered. For the adequate description of the optical properties of the LC modulator the necessary set of three characteristics is offered: contrast of the modulator, average on a range; the average on a range passage of the modulator for a status «is opened»; a modulator akhromatichnost is «open» for a status.

Model of the Miniature Modulator for Microwave Devices

Authors: Antonov I. N., Lavkin A. G., Mysenko M. B., Eryomin V. P., Rossoshanskiy A. V.

In the given paper the model of the miniature modulator for microwave devices is observed. The modulator consists of the master oscillator, which provides four series of the impulses, and of the inverter commutated with the surge generator providing a plate supply of the load. The pulsing plate supply of the load is stabilized by the current regulator on the unipolar transistor. The control and check unit realize the general control of the modulator. The optimal characteristic of the work of a magnetron is provided by the 16-digit microcontroller.

Comparison of Methods for Phase Synchronization Diagnostics from Test Data Modeling Nonstationary Signals of Biological Nature

Authors: Borovkova E. I., Karavaev A. S., Ponomarenko V. I., Prohorov M. D.

Three methods of phase synchronization diagnostics from time series are compared by the analysis of test data. These data reproduce the statistics of experimental temporal realizations recorded from the system of human cardiovascular system autonomic control.

Time-delayed Feedback Control of Coherence Resonance. Experimental Study

Authors: Semenov V. V., Vadivasova T. Е., Shell' E., Zakharova А. S.

In the paper a possibility to control the behavior of dynamic systems under conditions of coherent resonance using delayed feedback is proved experimentally. This problem is studied on the classical example of excitable system, which is the FitzHugh – Nagumo oscillator, as well as on the example of the Van der Pol oscillator with hard excitation, which also demonstrates the regime of coherent resonance. In both cases, when changing the delay time the feedback loop can both enhance and suppress the effect of coherent resonance.

Total Conversion of Terahertz Wave Polarization by Graphene Microribbon Array without Magnetic Field

Authors: Melnikova V. S., Polischuk O. V., Popov V. V.

The polarization conversion of terahertz radiation by the periodic array of graphene microribbons located at the surface of a high-refractiveindex dielectric substrate (prizm) is studied theoretically. Polarization conversion at the plasmon resonance frequencies takes place without applying external DC magnetic field. It is shown that giant (up to total) polarization conversion can be reached at the total internal reflection of THz wave from the periodic array of graphene nanoribbons.

On the Use of Optical Clearing in Strengthening the Sclera by Collagen Photocrosslinking

Authors: Shvachkina M. E., Pravdin A. B.

In the paper, the first evaluation results on the effect of optical clearing on the efficiency of the technique of eye sclera strengthening through the formation of riboflavin / ultraviolet collagen photocrosslinks are presented.

Compensation for Losses in a Resonant Circuit when Using Inertial Inductive and Capacitive Two-poles

Authors: Anishchenko V. S., Hohlov A. V.

Generalized linear inertial two-poles are introduced, and the eigen-oscillations are consi-dered in a series resonant LCR-circuit with a second-order inertial inductive element. It is shown that the introduction of the second order element is equivalent to entering negative damping into the resonant circuit.

Plasmonic Rectification of Terahertz Radiation in a Grating-gated Graphene

Authors: Mashinsky K. V., Fateev D. V., Popov V. V.

The theory of the plasmonic rectification of terahertz radiation in a homogeneous graphene gated by a metal grating with an asymmetric unit cell is developed.

Production of Tungsten Spherical Microparticles in Ultrasonic Field at Presence an Activator

Authors: Smirnov A. V., Atkin V. S., Grebennikov A. I., Revzina E. M., Kondrateva O. Y., Sinyov I. V.

It has been shown by experiments, that spherical tungsten microparticlein etching solution under the ultrasonic exposure is possible. The process of obtaining consists of two stages. At the first stage, by centrifuging a suspension of tungsten powder with an average particle size of 0.5 microns in the activator – etching from a water solution of potassium hydroxide and potassium ferricyanide, obtained tungsten thin plate of any shape, thickness 1–3 micrometers.

Morphology of Gas Sensitive Tin Dioxide Thin Films Operating at Room Temperature

Authors: Venig S. B., Mahdi O. S., Malyar I. V., Sinyov I. V., Smirnov A. V., Kisin V. V.

Tin dioxide thin films sensing ethanol vapors above the room temperature (38° C) were deposited by RF magnetron sputtering onto silicon substrates. Microstructure measurements using scanning electron microscopy and atomic force microscopy demonstrate that samples consist of grains shaped rods with nanometer diameters which are oriented normally to the substrate surface. There are pores between the grains penetrating the entire thickness of the films.

Morphological Changes in Transplanted Sarcoma S45 at Photodynamic Therapy Using Nanocomposites Based on Gold Nanorods

Authors: Bucharskaya A. B., Genina E. A., Bashkatov A. N., Terentyuk G. S., Navolokin N. A., Maslyakova G. N., Khlebtsov N. G., Khlebtsov B. N., Tuchin V. V.

Photodynamic therapy (PDT) of cancer is an advanced application of gold nanostructures. The purpose of the research is to study the morphological changes in the transplanted sarcoma S45 at PDT using nanocomposites based on gold nanorods (GNRs). GNRs synthesized with the germ method and covered by a silicon coating, functionalized by hematoporphyrin, were intratumorally injected in rats with transplanted sarcoma S45. The tumor was irradiated by He-Ne laser with a wavelength of 632.8 nm.

Phase Dynamics Modeling Technique for Estimation of Delayed Couplings between Nonlinear Oscillators Accounting for Influence of Amplitudes

Authors: Sidak E. V., Smirnov D. A., Bezruchko B. P.

An established interval estimator of a time delay in coupling between oscillators, which is based on empirical modeling of phase dynamics and maximum likelihood formalism, is shown to give sometimes erroneous conclusions about the value of the time delay. It occurs when the dynamics of amplitudes affects phases, which is typical of nonlinear oscillatory systems under the influence of strong noises or in chaotic regimes. We suggest an empirical criterion to diagnose such situations and a modified estimator of time delay which allows one to avoid erroneous conclusions.

Calculation of Scale Factors for Quantum-mechanical Force Fields

Authors: Berezin K. V., Novoselova A. V., Chernavina M. L., Berezin V. I., Novoselov V. V.

A computer-assisted method for the calculation of scaling factors for refining the quantum-mechanical force fields of polyatomic molecules by the Pulay technique is suggested. The method is an iteration procedure and does not involve the calculation of derivatives of the frequencies of vibrations with respect to the scaling factors.

IR Spectra of Salol and theirs Interpretation by Molecular Modeling

Authors: Babkov L. M., Davydova N. A., Ivlieva I. V.

IR spectra of salol have been measured at stable and metastable phases at temperature range from 11 to 298 K. IR spectra are different. We suggest that conformational mobility of salol and influence of H-bonding are responsible for the differences.

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