1,702 research outputs found

    Heat transfer in a one-dimensional harmonic crystal in a viscous environment subjected to an external heat supply

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    We consider unsteady heat transfer in a one-dimensional harmonic crystal surrounded by a viscous environment and subjected to an external heat supply. The basic equations for the crystal particles are stated in the form of a system of stochastic differential equations. We perform a continualization procedure and derive an infinite set of linear partial differential equations for covariance variables. An exact analytic solution describing unsteady ballistic heat transfer in the crystal is obtained. It is shown that the stationary spatial profile of the kinetic temperature caused by a point source of heat supply of constant intensity is described by the Macdonald function of zero order. A comparison with the results obtained in the framework of the classical heat equation is presented. We expect that the results obtained in the paper can be verified by experiments with laser excitation of low-dimensional nanostructures.Comment: 12 pages, 5 figure

    C-axis optical properties of high Tc cuprates

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    A review is given of the experimental status of the interlayer coupling energy in the cuprates. A second c-axis plasmon is identified in the double layer compound Y123 for various dopings. The anomalous transport properties along the c-direction and in the planar directions are compared to model calculations based on strongly anisotropic scattering. An excellent description of the optical data at optimal doping is obtained if an anomalously large anisotropy of the scattering rate between cold spots and hot spots is assumed. This raises questions as to the physical meaning of these parameters.Comment: 4 pages, LaTeX, espcrc2.sty, 3 figures in encapsulated postscript forma

    Digital Preservation and Web Access to the Konkoly Observatory Schmidt Telescope Plate Archive

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    ACM Computing Classification System (1998): J.2.The digital preservation of the Konkoly Observatory Schmidt telescope plates, as well as the web access to the plate previews, aim for the preservation of this scientific heritage and the re-use of the astronomical photographic plates in time domain astronomy. The photographic plates used as detectors and information storage at astronomical observations with the Konkoly Schmidt telescope had been obtained in the period 1962–1996. The work on the digital plate preservation and web access started in 2001 with creation of an electronic plate catalogue and the digitization of selected representative plates as well as with interlinking of the publishing in Konkoly Observatory Information Bulletin on Variable Stars (IBVS) with the Wide-Field Plate Database (WFPDB) developing in Sofia. We describe the process of the digitization of the Konkoly Schmidt telescope plates.This work is supported by the bilateral project between the Bulgarian Academy of Sciences and the Hungarian Academy of Sciences and partially by the grants BG NSF DO-02-273 and BG NSF DO-02-275
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