739 research outputs found

    Search for Cooper-pair Fluctuations in Severely Underdoped YBCO Films

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    The preformed-pairs theory of pseudogap physics in high-TCT_C superconductors predicts a nonanalytic TT-dependence for the abab-plane superfluid fraction, ρS\rho_S, at low temperatures in underdoped cuprates. We report high-precision measurements of ρS(T)\rho_S(T) on severely underdoped YBa2_2Cu3_3O6+x_{6+x} and Y0.8_{0.8}Ca0.2_{0.2}Ba2_2Cu3_3O6+x_{6+x} films. At low TT, ρS\rho_S looks more like 1T21 - T^2 than 1T3/21 - T^{3/2}, in disagreement with theory.Comment: 3 pages, 2 figure

    Temporary transnational labour mobility and gendered individualization in Europe

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    In a context of a new transnational division of labour, temporary international labour mobility is on the rise in Europe. In particular, recent decades have seen considerably more women seeking work experience abroad. Observers have been concerned with how such mobility is related to individualization, and in particular how it may challenge collective institutions, communities and families. The aim of this study is to explore such issues among women and men with international work experience. Using data from European Social Survey, the paper investigates previously mobile workers in terms of their current working and living conditions. Across genders, we consider different forms of individualization that may be associated with transnational labour mobility. While both women and men with transnational work experience generally feature strong strategic individualization, this is most pronounced among men. Hence, men's mobility is among other things associated with increased autonomy in working life, while–in contrast to women–it does not seem to hamper their integration in the sphere of social reproduction.info:eu-repo/semantics/publishedVersio

    A combined Raman lidar for low tropospheric studies

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    One of the main goals of laser sensing of the atmosphere was the development of techniques and facilities for remote determination of atmospheric meteorological and optical parameters. Of lidar techniques known at present the Raman-lidar technique occupies a specific place. On the one hand Raman lidar returns due to scattering on different molecular species are very simple for interpretation and for extracting the information on the atmospheric parameters sought, but, on the other hand, the performance of these techniques in a lidar facility is overburdened with some serious technical difficulties due to extremely low cross sections of Raman effect. Some results of investigations into this problem is presented which enables the construction of a combined Raman lidar capable of acquiring simultaneously the profiles of atmospheric temperature, humidity, and some optical characteristics in the ground atmospheric layer up to 1 km height. The operation of this system is briefly discussed

    Crystal structure and oxygen content of the double perovskites GdBaCo 2-xFexO6-δ

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    The iron solubility limit, x, in GdBaCo2-xFexO 6-δ determined by means of X-ray diffraction was found to be close to 0.65 in air. The crystal structure changes of the double perovskites GdBaCo2-xFexO6-δ (x=0-0.6) were studied by means of in situ X-ray diffraction in temperature range from 25 to 900 °C in air. The oxygen content, 6-δ, was determined for these double perovskites in air as a function of temperature by means of thermogravimetric technique in range 25≤T, °C≤ 1100. The Pmmm-P4/mmm structure transition was found to occur in GdBaCo2-xFexO 6-δ (0≤x≤0.4) with increasing temperature. This transition is observed at the same temperature for the compositions with 0≤x≤0.1 while the transition temperature reaches maximum for x=0.2 and that decreases linearly with further iron increase. The double perovskite GdBaCo1.4Fe0.6O6-δ was shown to have the tetragonal P4/mmm structure at room temperature. The P4/mmm-Pmmm structure transition occurs at temperature as low as 170 °C for this double perovskite while reverse one is already observed at 290 °C in air. The Pmmm-P4/mmm structure transition was found to be strongly related to the oxygen content for the undoped and slightly doped (x≤0.2) double perovskites while there is no such relation for the double perovskites enriched by iron (x≥0.2). © 2012 Elsevier Inc. All rights reserved

    Methods for estimating the optical constants of atmospheric hazes based on complex optical measurements

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    The methods of multifrequency laser sounding (MLS) are the most effective remote methods for investigating the atmospheric aerosols, since it is possible to obtain complete information on aerosol microstructure and the effective methods for estimating the aerosol optical constants can be developed. The MLS data interpretation consists in the solution of the set of equations containing those of laser sounding and equations for polydispersed optical characteristics. As a rule, the laser sounding equation is written in the approximation of single scattering and the equations for optical characteristics are written assuming that the atmospheric aerosol is formed by spherical and homogeneous particles. To remove the indeterminacy of equations, the method of optical sounding of atmospheric aerosol, consisting in a joint use of a mutifrequency lidar and a spectral photometer in common geometrical scheme of the optical experiment was suggested. The method is used for investigating aerosols in the cases when absorption by particles is small and indicates the minimum necessary for interpretation of a series of measurements

    The influence of scattering particles morphology on the characteristics of lidar signals

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    The characteristics of light scattering by a separate spherical particle are used as a priori information when interpreting the data on laser sounding of atmospheric aerosols. Analogously, it is necessary to have a priori information on the characteristics of light scattering by a single crystals in order to restitute the microstructure of crystal formation in the atmosphere. In contrast to the aerosol particles the crystals are of different shapes. On the one hand, this complicates the solution of electrodynamic problems on light scattering by such crystals. On the other hand, if obtaining such a solution is possible, one can determine the morphology of scattering particles accoring to the sounding data and this enables additonal information to be obtained on such meteorological parameters as temperature, pressure, and humidity. Using the geometric-wave approach the problem of scattering of plane electromagnetic wave on convex polyhedrons of arbitrary form was solved. As a result, the expressions were obtained for electric field components of perpendicular and parallel polarizations scattered in any given direction

    Problems of training for ERP-systems

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    В данной статье предпринята попытка на основе изучения материалов, представленных в Интернет-источниках, проанализировать ряд проблем, связанных с подготовкой специалистов по (Enterprise Resources Planning) ERP-системам.In given article attempt on the basis of studying of the materials presented in Internet sources is undertaken, to analyse a number of the problems connected with preparation of experts on ERP (Enterprise Resources Planning) to systems

    Thermoelectric behavior of BaZr0.9Y0.1O3−d proton conducting electrolyte

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    BaZr0.9Y0.1O3-δ (BZY10), a promising proton conducting material, exhibits p-type conduction under oxidative conditions. Holes in BZY10 are of the small polaron type. However, there is no clear understanding at which places in the lattice they are localized. The main objectives of this work were, therefore, to discuss the nature of electronic defects in BZY10 on the basis of the combined measurements of the thermo-EMF and conductivity. Total electrical conductivity and Seebeck coefficient of BZY10 were simultaneously studied depending on partial pressures of oxygen (pO2), water (pH2O) and temperature (T). The model equation for total conductivity and Seebeck coefficient derived on the basis of the proposed defect chemical approach was successfully fitted to the experimental data. Transference numbers of all the charge carriers in BZY10 were calculated. The heat of transport of oxide ions was found to be about one half the activation energy of their mobility, while that of protons was almost equal to the activation energy of their mobility. The results of the Seebeck coefficient modeling indicate that cation impurities, rather than oxygen sites, should be considered as a place of hole localization. © 2019 by the authors. Licensee MDPI, Basel, Switzerland.Russian Science Foundation, RSF: 18-73-00022Funding: This work was supported by the Russian Science Foundation (project No. 18-73-00022

    New Evidence for Supernarrow Dibaryons Production in pd Interactions

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    The analysis of new experimental data, obtained at the Proton Linear Accelerator of INR, with the aim to search for supernarrow dibaryons in the pdppX1pd\to ppX_1 and pdpdX2pd\to pdX_2 reactions is presented. Narrow peaks with an experimental width of 5 MeV at masses of 1904±2\pm 2, 1926±2\pm 2, and 1942±2\pm 2 MeV have been observed in missing mass MpX1M_{pX_1} spectra. In the missing mass MX1M_{X_1} spectra, the peaks at MX1=966±2M_{X_1}=966\pm 2, 986±2\pm 2, and 1003±2\pm 2 MeV have been found. The analysis of the data obtained leads to the conclusion that the observed peaks in MpX1M_{pX_1} spectra are most likely supernarrow dibaryons, the decay of which into two nucleons is forbidden by the Pauli exclusion principle. An alternative interpretation of the spectra by assuming a decay of the supernarrow dibaryons in "exotic baryon states" with masses MX1M_{X_1} is discussed.Comment: 17 pages, 6 figures. Considerably expanded version accepted for publication in Eur. Phys. J. A; a discussion, 4 figures and several references have been added, the title has been change

    Multifrequency dial sensing of the atmospheric gaseous constituents using the first and second harmonics of a tunable CO2 laser radiation

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    The results of field measurements of concentration of some gaseous components of the atmosphere along the paths, in Sofia, Bulgaria, using a gas analyzer based on the use of a CO2 laser radiation frequency-doubled with ZnGeP2 monocrystals are presented. The gas analyzer is a traditional long path absorption meter. Radiation from the tunable CO2 laser of low pressure and from an additional He-Ne laser is directed to a colliminating hundredfold Gregori telescope with a 300 mm diameter of the principal mirror. The dimensions of the mirrors of a retroreflector 500 x 500 mm and a receiving telescope allow one to totally intercept the beam passed through the atmospheric layer under study and back
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