145 research outputs found

    Measurements of light background at large depth in the ocean

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    The mean intensity of Cerenkov emission from the products of K(40) decay and bioluminescence was measured at depths to 5 km. The intensity of ocean light background is found to depend upon depth and at the 5 km level is equal on averaged to 300 + or - 60 quanta/sq cms into spatial angle of 2 pi sterradian in transparency window. The amplitudes, duration and number of BL flashes were measured at various depths. The intensive flashes due to BL are shown to be observed rather seldom at depths over 4 km

    Structure and stresses in a system of two mechanical twins in titanium

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    In the work we have presented the results of experimental studies and mathematical modeling for the processes of the structure formation in a transition zone of wedge-type twins system in commercially pure titanium. The process of interaction of structure defects with twinning dislocations during the formation of a wedge-type twin was taken into consideration. It is shown that the interaction alters the stress maximum in vicinity of boundaries in the system two wedge-type twi

    Electrical conductivity and dielectric relaxation processes of the ceramic system Y2O3-ZrO2-SrTiO3-BiScO3

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    The ceramic system Y2O3-ZrO2-SrTiO3-BiScO3 was synthesized by the reaction method in the solid phase. The frequency and temperature dependences of the electrical conductivity of Y2O3-ZrO2-SrTiO3-BiScO3 ceramics are obtained. At a temperature above 500 K, the dielectric relaxation of the Y2O3-ZrO2-SrTiO3-BiScO3 ceramic system was detected, the activation energy of the relaxation process was 1.25 e

    Nanostructured coatings based on amorphous carbon and gold nanoparticles obtained by the pulsed vacuum-arc method

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    Nanostructured coatings based on diamond-like carbon and gold-doped carbon with a thickness of 100-300 nm were obtained by a pulsed vacuum-arc method on silicon substrates. The structure of the coatingswas studied by high-resolution transmission electron microscopy, the elemental composition was studied by X-ray microanalysi

    Features of optical characteristics of atmospheric aerosol in the Middle Urals

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    The results of studies into the aerosol optical depth (AOD) for the atmosphere in the Middle Urals in the spectrum range of 0.34-1.02 μm for 2004-2010 is presented. The interannual, annual, seasonal, and daily variations in the AOD are analyzed. The major statistical characteristics of the AOD, the parameters of the probability density function of distributions over different wave lengths, and the parameters of Angstrom's formula for the different seasons are calculated. The monitoring stations in the Russian segment of the AERONET network are ranked with respect to the AOD value. A shift from March to May in the spring maximum of the AOD is revealed in comparison with the results of the actinometric observations for the period of 1960-1986. A qualitative assessment is given to the influence of forest and peat fires in the region on the AOD. A classification of the states of aerosol haze in the atmosphere according to the AOD values is proposed. © 2013 Pleiades Publishing, Ltd

    Extensive Chaos in the Nikolaevskii Model

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    We carry out a systematic study of a novel type of chaos at onset ("soft-mode turbulence") based on numerical integration of the simplest one dimensional model. The chaos is characterized by a smooth interplay of different spatial scales, with defect generation being unimportant. The Lyapunov exponents are calculated for several system sizes for fixed values of the control parameter ϵ\epsilon. The Lyapunov dimension and the Kolmogorov-Sinai entropy are calculated and both shown to exhibit extensive and microextensive scaling. The distribution functional is shown to satisfy Gaussian statistics at small wavenumbers and small frequency.Comment: 4 pages (including 5 figures) LaTeX file. Submitted to Phys. Rev. Let

    Structural features and physico-mechanical properties of AlN-TiB2-TiSi2 amorphous-like coatings

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    The coating of the AlN–TiB2–TiSi2 system has been produced by the magnetron sputtering of a target. At the hightemperature (900 and 1300°C) actions the coating crystallization to form crystallites of sizes 11–25 nm has been observed. It has been defined that the amorphouslike structure is promising for the use of these coatings as diffusion barriers both as the independent elements and a contacting layer in multilayer wearresistant coatings. It has been shown that the use of the resultant composite as an effec tive protective coating for cutting tools will make it possible to increase the tools wear resistance by more than 30% at the temperature up to 1300°C in the cutting zone

    Structural features and physico-mechanical properties of AlN-TiB2-TiSi2 amorphous-like coatings

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    The coating of the AlN–TiB2–TiSi2 system has been produced by the magnetron sputtering of a target. At the hightemperature (900 and 1300°C) actions the coating crystallization to form crystallites of sizes 11–25 nm has been observed. It has been defined that the amorphouslike structure is promising for the use of these coatings as diffusion barriers both as the independent elements and a contacting layer in multilayer wearresistant coatings. It has been shown that the use of the resultant composite as an effec tive protective coating for cutting tools will make it possible to increase the tools wear resistance by more than 30% at the temperature up to 1300°C in the cutting zone

    Influence of residual pressure and ion implantation on the structure, elemental composition, and properties of (TiZrAlYNb)N nitrides

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    The nitrides of highentropy alloys, (TiZrAlYNb)N, fabricated by cathodic vacuum arc evaporation are studied with electron microscopy, atomic force microscopy, laser scanning microscopy; energydispersive Xray analysis, Xray phase analysis, timeofflight secondaryion mass spectrometry; and hardness measurements. It is found that the deposition parameters influence the structure, surface morphology, element distribution, and mechanical properties. The structural–phase state of the coatings before and after the ion implantation of heavy negative gold ions Au– are compared. DOI: 10
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