2,266 research outputs found

    Влияние различных факторов на прочность торфяных термобрикетов

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    In-situ observation of the in-volume modification of glasses by focused ultra-short pulsed laser radiation with an interferometer microscope allows for the spatially resolved measurement of the transient optical path difference (OPD) in the surrounding of the laser-induced modification. By the relation of refractive index and temperature an estimation of temperature during modification process is possible. The absorption of the laser radiation is measured and is, together with the estimation of processing temperature during modification, a first step towards a process model for the induced modifications of the transparent material

    Application of image recognition theory in non-destructive radiation testing of materials quality used in extreme conditions

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    Для обнаружения дефектов материалов и деталей космических аппаратов используетсярадиационный метод неразрушающего контроля. Обработка изображений, получаемых этим методом, проводится с помощью специальных алгоритмов. В работе обоснована возможность использования нейросетевого метода и предложен алгоритм на его основе для распознавания образов.The radiation method of nondestructive testing is used for the detection of defects in materials and components of spacecraft. Processing of the images, obtained by this method, is carried out using specialized algorithms. In the paper the possibility of using neural networks method is considered and the algorithm for image recognition based on it is suggested

    Информационная система образовательного отдела администрации города Юрги

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    Sintered targets of Al2O3 are removed by CO(2-) and excimer laser radiation and deposited as thin films onto steel and silicon substrates. Micro Raman spectroscopy and atomic force microscopy are used to characterize the morphological and structural properties of the films. Mechanical properties are investigated by nanoindentation measurements and a laser-acoustic method, optical properties are studied by ellipsometry. Al2O3 films deposited using CO2-laser radiation show an inhomogeneous surface structure with droplets embedded in a matrix, whereas the films deposited using excimer laser radiation are smooth, which is explained by different material removal mechanisms. The microhardness (i.e. ratio of indentation load to residual area of the indent) of the amorphous matrix structure is about 8 GPa, the crystalline droplets are softer at about 2 GPa. Varying the processing gas pressures in the range of 0.0 1 -0.6 mbar yields a change in the index of refraction of the films, which is clo se to the bulk value for gas pressures < 0.1 mbar. The decrease of the index of refraction is caused by a lowered film density, correlating with a lowered mean energy,of the particles impinging on the substrate, which is calculated. The results show the possibility of scaling-up the pulsed laser deposition process for industrial applications by use of C02-laser radiation

    Температурные режимы работы твэлов реактора ИРТ-Т

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    Приведены результаты теплофизических расчетов активной зоны реактора ИРТ-Т. Показано, что при номинальной мощности реактора температурные режимы твэлов укладываются в предельные значения и соответствуют требованиям технического обоснования безопасности

    The effect of relative plasma plume delay on the properties of complex oxide films grown by multi-laser multi-target combinatorial pulsed laser deposition

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    We report the effects of relative time delay of plasma plumes on thin garnet crystal films fabricated by dual-beam, combinatorial pulsed laser deposition. Relative plume delay was found to affect both the lattice constant and elemental composition of mixed Gd3Ga5O12 (GGG) and Gd3Sc2Ga5O12 (GSGG) films. Further analysis of the plasmas was undertaken using a Langmuir probe, which revealed that for relative plume delays shorter than ~200 µs, the second plume travels through a partial vacuum created by the first plume, leading to higher energy ion bombardment of the growing film. The resulting in-plane stresses are consistent with the transition to a higher value of lattice constant normal to the film plane that was observed around this delay value. At delays shorter than ~10 µs, plume propagation was found to overlap, leading to scattering of lighter ions from the plume and a change in stoichiometry of the resultant films

    Результативность силовой подготовки спортсменов в атлетических видах спорта

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    Ultrashort laser sources with pulse durations of around a few or below 1 picosecond and average powers above 1 KW enable a new domain in precision machining. They enable extreme-precision cutting, ablation and drilling of even weakly absorbing materials, multi-component and multilayer systems

    The 2001 Mars In-Situ-Propellant-Production Precursor (MIP) Flight Demonstration

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    The successful performance of the five individual demonstrations of MARS IN-SITU-PROPELLANT-PRODUCTION PRECURSOR (MIP) will provide both knowledge of and confidence in the reliability of this technology. At the completion of this flight demonstration, the MIP Team will be able to: a) recommend preferred hardware configurations for the intake and adsorption of carbon dioxide from the Martian atmosphere; b) understand the performance characteristics of zirconia cells to generate propellant-grade oxygen; c) understand long-term performance characteristics of advanced solar cells/arrays operated in the actual Mars environment; d) evaluate the functionality of methods to mitigate the deposition of airborne dust onto solar arrays; and e) recommend preferred hardware designs for innovative thermal management including the radiation of heat to the outside environment

    The contours of a new urban world? Megacity population growth and density since 1975

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    The problems posed by rapid and large-scale urbanisation are manifold, and are recognised in the UN’s New Urban Agenda; a declaration of intent that aims to meet such challenges head-on facilitated by the systematic tracking and analysis of global urban growth and change. In this context, the release in 2016 of new small area Global Human Settlement Layer (GHSL) data was said to represent a unique opportunity to facilitate comparative global analyses of urban change dynamics and, perhaps somewhat idealistically, move forward progressive planning agendas. We therefore focus on population growth and density in 30 major urban agglomerations using the GHSL in order to shed light on the scale and extent of global urbanisation over the past four decades and to interrogate the potential role of the GHSL in tracking urban change