1,279 research outputs found

    Транспорт как модератор социальных отношений: локусы напряжения и факторы стабилизации

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    Громадський транспорт як функціональна система для задоволення найважливіших суспільних потреб утворює особливу сферу соціокультурних відносин зі своїми просторовими і часовими межами, обумовленими комплексом рольових очікувань і засвоєних цінностей. Повсякденна культура громадського транспорту являє собою ціннісну систему, синтез формальних правил і неформальних домовленостей, в рамках яких складаються статусні взаємодії споживачів і представників транспортної послуги, відтворюються дискримінаційні практики, формуються цінності і норми пасажирської та водійської спільноти, перетворюючись на зразки дій. Стаття присвячена аналізу вузлових моментів функціонування транспорту з соціологічної точки зору, визначаються основні перспективні напрямки подальших досліджень.Public transportation is a functional system, which aim is to satisfy critical public needs. It forms a special sphere of socio-cultural relations with their spatial and temporal boundaries and is determined by the complex role expectations and internalized values. Everyday culture of public transport is a value system, a synthesis of formal rules and informal arrangements in which the status of interaction between consumers and representatives of transport services is being formed, discriminatory practices are being reproduced, values and norms of the passenger and driver community are being formed and become models for action. Public transport is an integral component of urban culture of everyday life, which works out in the framework of the particular collective experience of the variations of human relationships, including the distinctive value-symbolic and structural dimensions of cultural practices. Therefore, it is necessary to deepen the understanding of conditions for creation and changes of social and cultural order of transport commonness, in particular, professional subculture of drivers of public transport, the elements of solidarity of temporary passenger communities and civil potential users of transport services, which are made in the process of daily practices. Sociological analysis of these aspects is of considerable interest both for theoretical and practical understanding of social and cultural relations, mediated by the transport sector. It stands in line with the applied problems of improvement of transport services as an element of urban policy. Transport space acts as a special value in conditions of deficiency and becomes the reason for competition on resource, determining the features of temporary bodily practices of the community, rules of distribution and zoning of the internal spaces, creating a synthesis of traditional knowledge and tactics of the actors in the everyday drama. The text in the form of cognitive map, that is, the visual image of the space reflects the experience of the subject, the image in the form of a drawing or diagram, appears as a way of seeing the geography from the passenger routine. Sociological study of the transport sectors is innovative and perspective. Sociologists will have to study comprehensive central points of the development of transport industry, the role of transport in social processes, socio-cultural determination of functioning, the specifics of norm-formation, and so on.Общественный транспорт как функциональная система для удовлетворения важнейших общественных потребностей образует особую сферу социокультурных отношений со своими пространственными и временными границами, определяемыми комплексом ролевых ожиданий и усвоенных ценностей. Повседневная культура общественного транспорта представляет собой ценностную систему, синтез формальных правил и неформальных договоренностей, в рамках которых состоят статусные взаимодействия потребителей и представителей транспортной услуги, воспроизводятся дискриминационные практики, формируются ценности и нормы пассажирского и водительского сообщества, превращаясь в образцы действий. Статья посвящена анализу узловых моментов функционирования транспорта с социологической точки зрения, определяются основные перспективные направления дальнейших исследовани

    Charge Modulation at the Surface of High-T_c Superconductors

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    It is shown here that surfaces of high-temperature superconductors are covered by dipole layers. The charge density modulation is induced by the local suppression of the gap function at the surface. This effect is studied in the framework of the Ginzburg-Landau theory and crucially depends on the appropriate boundary conditions. Those are derived from Gor'kov's equations for a d-wave pairing symmetry. Within this framework the structure of the surface dipole layer is determined. The contribution of this charging to a lens-effect of superconducting films with holes, which has been studied in recent experiments, is discussed.Comment: 10 pages, RevTeX, 5 postscript figure

    The Ethnic 'Other' in Ukrainian History Textbooks: The Case of Russia and the Russians

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    This paper examines portrayals of Russia and the Russians in two generations of Ukrainian history textbooks. It observes that the textbooks are highly condemning of Ukraine's main ethnic other in the guise of foreign ruler: the tsarist authorities and the Soviet regime are always attributed dubious and malicious intentions even if there is appreciation for some of their policies. By contrast, the books, certainly those of the second generation, refrain from presenting highly biased accounts of the ethnic other as a national group (i.e. Russians). Instances where negative judgements do fall onto Russians are counterbalanced by excerpts criticizing ethnic Ukrainians or highlighting conflicting interests within the Ukrainian ethnic group. The negative appraisal of the ethnic other as foreign ruler is clearly instrumental for the nation-building project as it sustains a discourse legitimating the existence of Ukraine as independent state. However, recent trends in history education, the paper concludes, suggest that the importance of nurturing patriotism as a national policy objective is diminishing

    Approximate Ginzburg-Landau solution for the regular flux-line lattice. Circular cell method

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    A variational model is proposed to describe the magnetic properties of type-II superconductors in the entire field range between Hc1H_{c1} and Hc2H_{c2} for any values of the Ginzburg-Landau parameter κ>1/2\kappa>1/\sqrt{2}. The hexagonal unit cell of the triangular flux-line lattice is replaced by a circle of the same area, and the periodic solutions to the Ginzburg-Landau equations within this cell are approximated by rotationally symmetric solutions. The Ginzburg-Landau equations are solved by a trial function for the order parameter. The calculated spatial distributions of the order parameter and the magnetic field are compared with the corresponding distributions obtained by numerical solution of the Ginzburg-Landau equations. The comparison reveals good agreement with an accuracy of a few percent for all κ\kappa values exceeding κ1\kappa \approx 1. The model can be extended to anisotropic superconductors when the vortices are directed along one of the principal axes. The reversible magnetization curve is calculated and an analytical formula for the magnetization is proposed. At low fields, the theory reduces to the London approach at κ1\kappa \gg 1, provided that the exact value of Hc1H_{c1} is used. At high fields, our model reproduces the main features of the well-known Abrikosov theory. The magnetic field dependences of the reversible magnetization found numerically and by our variational method practically coincide. The model also refines the limits of some approximations which have been widely used. The calculated magnetization curves are in a good agreement with experimental data on high-Tc_c superconductors.Comment: 8 pages, RevTex, 6 figures, submitted to Phys. Rev.

    Vortex phases in mesoscopic cylinders with suppressed surface superconductivity

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    Vortex structures in mesoscopic cylinder placed in external magnetic field are studied under the general de Gennes boundary condition for the order parameter corresponding to the suppression of surface superconductivity. The Ginzburg-Landau equations are solved based on trial functions for the order parameter for vortex-free, single-vortex, multivortex, and giant vortex phases. The equilibrium vortex diagrams in the plane of external field and cylinder radius and magnetization curves are calculated at different values of de Gennes "extrapolation length" characterizing the boundary condition for the order parameter. The comparison of the obtained variational results with some available exact solutions shows good accuracy of our approach.Comment: RevTex, 11 pages, 10 figure

    Quantum Disorder and Quantum Chaos in Andreev Billiards

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    We investigate the crossover from the semiclassical to the quantum description of electron energy states in a chaotic metal grain connected to a superconductor. We consider the influence of scattering off point impurities (quantum disorder) and of quantum diffraction (quantum chaos) on the electron density of states. We show that both the quantum disorder and the quantum chaos open a gap near the Fermi energy. The size of the gap is determined by the mean free time in disordered systems and by the Ehrenfest time in clean chaotic systems. Particularly, if both times become infinitely large, the density of states is gapless, and if either of these times becomes shorter than the electron escape time, the density of states is described by random matrix theory. Using the Usadel equation, we also study the density of states in a grain connected to a superconductor by a diffusive contact.Comment: 20 pages, 10 figure

    Phenomenological description of the microwave surface impedance and complex conductivity of high-TcT_c single crystals

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    Measurements of the microwave surface impedance Zs(T)=Rs(T)+iXs(T)Z_s(T)=R_s(T)+iX_s(T) and of the complex conductivity σs(T)\sigma_s(T) of high-quality, high-TcT_c single crystals of YBCO, BSCCO, TBCCO, and TBCO are analyzed. Experimental data of Zs(T)Z_s(T) and σs(T)\sigma_s(T) are compared with calculations based on a modified two-fluid model which includes temperature-dependent quasiparticle scattering and a unique temperature variation of the density of superconducting carriers. We elucidate agreement as well as disagreement of our analysis with the salient features of the experimental data. Existing microscopic models are reviewed which are based on unconventional symmetry types of the order parameter and on novel mechanisms of quasiparticle relaxation.Comment: 15 pages, 17 figures, 1 tabl

    Differential branching fraction and angular analysis of the decay B0→K∗0μ+μ−

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    The angular distribution and differential branching fraction of the decay B 0→ K ∗0 μ + μ − are studied using a data sample, collected by the LHCb experiment in pp collisions at s√=7 TeV, corresponding to an integrated luminosity of 1.0 fb−1. Several angular observables are measured in bins of the dimuon invariant mass squared, q 2. A first measurement of the zero-crossing point of the forward-backward asymmetry of the dimuon system is also presented. The zero-crossing point is measured to be q20=4.9±0.9GeV2/c4 , where the uncertainty is the sum of statistical and systematic uncertainties. The results are consistent with the Standard Model predictions

    Measurement of the relative rate of prompt χc0, χc1 and χc2 production at √s=7TeV

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    Prompt production of charmonium χc0, χc1 and χc2 mesons is studied using proton-proton collisions at the LHC at a centre-of-mass energy of √s=7TeV. The χc mesons are identified through their decay to J/ψγ, with J/ψ→μ+mu− using photons that converted in the detector. A data sample, corresponding to an integrated luminosity of 1.0fb−1 collected by the LHCb detector, is used to measure the relative prompt production rate of χc1 and χc2 in the rapidity range 2.0<y<4.5 as a function of the J/ψ transverse momentum from 3 to 20 GeV/c. First evidence for χc0 meson production at a hadron collider is also presented
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