17,287 research outputs found

    Japanese activities in refrigeration technology

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    Recent activities in refrigeration technology in Japan are discussed. Stirling cycle refrigerators and magnetic refrigerators are discussed. The development of units for use on trains is discussed

    The X-ray Structure of A399 and A401: A Pre-Merging Cluster Pair

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    We present {\em ASCA} results of the pair clusters A399 and A401. The region between the two clusters exhibits excess X-rays over the value expected with a simple superposition of the two clusters. We see, however, no temperature rise at the merging front; the temperature is near the average of those in the inner regions of the two clusters. These indicate that the two clusters are really interacting but it is not strong at present. The inner regions of the two clusters show no radial variations of temperature, abundance and absorption values. We set upper-limits of mass deposition rate of cooling flow to be M˙<35  Myr1\dot{M}<35\;\rm M_{\odot}yr^{-1} and M˙<59  Myr1\dot{M}<59\;\rm M_{\odot}yr^{-1} for A399 and A401, respectively. A hint of azimuthal variation of the temperature is also found.Comment: 17 pages, 13 postscript figures, 2 external tables, accepted for publication in PAS

    Unique representation d=4k(k^2-1) in D(4)-quadruples {k-2,k+2,4k,d}

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    Let k ≥ 3 be an integer. We show that if d is a positive integer such that the product of any two distinct elements of the set {k-2,k+2,4k,d} increased by 4 is a square, then d must be 4k(k^2-1)

    Time-dependent, species-specific effects of N:P stoichiometry on grassland plant growth

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    N and P have different eutrophication effects on grassland communities, yet the underlying mechanisms are poorly understood. To examine plant growth in response to the varying (relative) supply of N and P, we conducted a two-year greenhouse experiment. Five grasses and three herbs were grown with three N:P supply ratios at two overall nutrient supply levels. During the first year the plant growth was relatively low at both high and low N:P supply ratios, whereas during the second year the growth was especially low at a high N:P supply ratio. This second-year low growth was attributed to the high root death rate, which was influenced by a high N:P supply ratio rather than by the nutrient supply level. Species responded differently, especially in P uptake and loss at a high N:P supply ratio. Each species seemed to have a different strategy for P limitation, e.g. an efficient P uptake or a high P resorption rate. Species typical of P-limited grasslands had neither better P uptake nor better P retention at a high N:P supply ratio. This study quantitatively demonstrates an increased plant root death triggered by strong P limitation. This finding indicates a possible extra effect of N eutrophication on ecosystem functioning via changed N:P stoichiometr

    The Variation of Gas Mass Distribution in Galaxy Clusters: Effects of Preheating and Shocks

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    We investigate the origin of the variation of the gas mass fraction in the core of galaxy clusters, which was indicated by our work on the X-ray fundamental plane. The adopted model supposes that the gas distribution characterized by the slope parameter is related to the preheated temperature. Comparison with observations of relatively hot (~> 3 keV) and low redshift clusters suggests that the preheated temperature is about 0.5-2 keV, which is higher than expected from the conventional galactic wind model and possibly suggests the need for additional heating such as quasars or gravitational heating on the largest scales at high redshift. The dispersion of the preheated temperature may be attributed to the gravitational heating in subclusters. We calculate the central gas fraction of a cluster from the gas distribution, assuming that the global gas mass fraction is constant within a virial radius at the time of the cluster collapse. We find that the central gas density thus calculated is in good agreement with the observed one, which suggests that the variation of gas mass fraction in cluster cores appears to be explained by breaking the self-similarity in clusters due to preheated gas. We also find that this model does not change major conclusions on the fundamental plane and its cosmological implications obtained in previous papers, which strongly suggests that not only for the dark halo but also for the intracluster gas the core structure preserves information about the cluster formation.Comment: 17 pages, to be published in Ap

    Klinische Untersuchungen über die Resorptionskraft aus dem Subcutis

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    Nach Donath u. Tanne haben wir die Resorptionszeit des Uranins aus dem Subcutis bei verschiedenartigen Kranken untersucht. Unter den Resultaten sind die folgenden hervorzuheben; bei Morbus Basedowi, Kreislaufinsuffizienzien, hydropischen Nephritiden, Beriberi, Leberkrankheiten, Pleuritiden, bes. bei frischen Fällen und schweren Tuberkulosen wurde die Resorption mehr oder weniger erheblich verlangsamt. Bei Ankylostomiaden war sie bald unverändert, bald eher verlangsamt, bes. verlangsamt bei denen mit hochgradiger Anämie. Bei Pleuritiden war es verschieden je nach den Krankheitsstadien, da sie z. B. bei frischen, zur Exsudation neigenden Fällen verlangsam war, während sie mit der Krankheitsbesserung zusammen immer schneller wurde und bei veralteten, mit Schwartenbildung oder mit immer gröber werdenden Reiben behafteten Fällen sogar fast normal war. Für den Ausfall dieser Probe spielt nicht nur der Zustand des Kreislaufes, wie die Blutströmungsgeschwindigkeit und die Blutdruckamplitude etc, wie Donath u. Tanne annahm, eine gewisse Rolle, sondern auch der Gewebszustand, dieser sogar eher grössere Rolle

    Synchrotron X-ray diffraction study of a charge stripe order in 1/8-doped La1.875_{1.875}Ba0.125x_{0.125-x}Srx_{x}CuO4_{4}

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    Lattice distortions associated with charge stripe order in 1/8 hole-doped La1.875_{1.875}Ba0.125x_{0.125-x}Srx_{x}CuO4_{4} are studied using synchrotron X-ray diffraction for x=0.05x=0.05 and x=0.075x=0.075. The propagation wave vector and charge order correlation lengths are determined with a high accuracy, revealing that the oblique charge stripes in orthorhombic x=0.075x=0.075 crystal are more disordered than the aligned stripes in tetragonal x=0.05x=0.05 crystal. The twofold periodicity of lattice modulations along the c-axis is explained by long-range Coulomb interactions between holes on neighboring CuO2_{2} planes.Comment: 4pages, 4figures, Submitted to PR