632 research outputs found

    Sub-Wavelength Terahertz Spin-Flip Laser Based on a Magnetic Point-Contact Array

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    We present a novel design for a single-mode, truly sub-wavelength THz disk laser based on a nano-composite gain medium comprising an array of metal/ferromagnetic point contacts embedded in a thin dielectric layer. Stimulated emission of light occurs in the point contacts as a result of spin-flip relaxation of spin-polarized electrons that are injected from the ferromagnetic side of the contacts. Ultra-high electrical current densities in the contacts and a dielectric material with a large refractive index, neither condition being achievable in conventional semiconductor media, allows the thresholds of lasing to be overcome for the lowest-order modes of the disk, hence making single-mode operation possible.Comment: 9 pages,4 figure

    Estimation of Innovative Activity of the University

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    On the basis of Belgorod region innovation activity analysis, positive relationship between shipped innovation items and domestic research and development costs was found. Semantic differential was used for multiple estimation of BelSU innovation activity and competiveness. BelSU integrated index showed high-enough innovation activity of this universityyesBelgorod State Universit

    Virality of medical content in Russian social media

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    The work objective is to conduct a sociological study aimed at assessing validity (appropriateness) of the traditional characteristics and formation of a pool of specialized characteristics of the viral content, used in the promotion of health services by means of social media marketin

    Electron-phonon interaction via Pekar mechanism in nanostructures

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    We consider an electron-acoustic phonon coupling mechanism associated with the dependence of crystal dielectric permittivity on the strain (the so-called Pekar mechanism) in nanostructures characterized by strong confining electric fields. The efficiency of Pekar coupling is a function of both the absolute value and the spatial distribution of the electric field. It is demonstrated that this mechanism exhibits a phonon wavevector dependence similar to that of piezoelectricity and must be taken into account for electron transport calculations in an extended field distribution. In particular, we analyze the role of Pekar coupling in energy relaxation in silicon inversion layers. Comparison with the recent experimental results is provided to illustrate its potential significance

    Expansion introductions of civil examination: technologies and approaches

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    In study, it is carried out theoretical the analysis of information on efficiency of expert activity and introduction of civil examination to practice of regional government. The concept of civil examination and indicators of its social and economic efficiency is considered. The principles, conditions and technologies of realization of civil examination are registered. Results of research of a problem of civil participation in management process, development, acceptances and implementation of administrative decisions at regional level are considere

    Holographic Structure Transfer from Dichromated Gelatin Layers to a Polymethylmethacrylate Substrate

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    It is shown that the formation of a holographic structure on the polymethylmethacrylate (PMMA) surface is based on the use of the destructive effect of short-wave UV radiation with a wavelength less than 270 nm through windows previously formed in a thin layer of dichromated gelatin (DCG) covering the substrate. The optimization of the PMMA surface treatment by isopropanol and methylisobutyl ketone (MIBK) developers was made, which allowed creating on the PMMA substrates relief-phase holographic gratings with the high diffraction efficiency (DE) of about 25% and maximum depth of the surface relief of the order of 1 μm. Keywords: holographic gratings, surface relief, UV radiation, dichromated gelatin, polymethylmethacrylate, methylisobutyl ketone (MIBK)
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