49,778 research outputs found

    Neutron-image intensifier

    Get PDF
    Electronic intensifier tube with a demagnification ratio of 9-1 enhances the usefulness of neutron-radiographic techniques. A television signal can be obtained by optical coupling of a small-output phosphor-light image to a television camera

    Persistence of singlet fluctuations in the coupled spin tetrahedra system Cu2Te2O5Br2 revealed by high-field magnetization and 79Br NQR - 125Te NMR

    Full text link
    We present high-field magnetization and 79^{79}Br nuclear quadrupole resonance (NQR) and 125^{125}Te nuclear magnetic resonance (NMR) studies in the weakly coupled Cu2+^{2+} (S=1/2S=1/2) tetrahedral system Cu2_2Te2_2O5_5Br2_2. The field-induced level crossing effects were observed by the magnetization measurements in a long-ranged magnetically ordered state which was confirmed by a strong divergence of the spin-lattice relaxation rate 1/T1 at T0=13.5 K. In the paramagnetic state, 1/T1 reveals an effective singlet-triplet spin gap much larger than that observed by static bulk measurements. Our results imply that the inter- and the intra-tetrahedral interactions compete, but at the same time they cooperate strengthening effectively the local intratetrahedral exchange couplings. We discuss that the unusual feature originates from the frustrated intertetrahedral interactions.Comment: 5 pages, 4 figures, accepted in Phys. Rev. B as a Rapid Communication

    Bayesian Nonparametric Shrinkage Applied to Cepheid Star Oscillations

    Full text link
    Bayesian nonparametric regression with dependent wavelets has dual shrinkage properties: there is shrinkage through a dependent prior put on functional differences, and shrinkage through the setting of most of the wavelet coefficients to zero through Bayesian variable selection methods. The methodology can deal with unequally spaced data and is efficient because of the existence of fast moves in model space for the MCMC computation. The methodology is illustrated on the problem of modeling the oscillations of Cepheid variable stars; these are a class of pulsating variable stars with the useful property that their periods of variability are strongly correlated with their absolute luminosity. Once this relationship has been calibrated, knowledge of the period gives knowledge of the luminosity. This makes these stars useful as "standard candles" for estimating distances in the universe.Comment: Published in at http://dx.doi.org/10.1214/11-STS384 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

    Study of infrared evaluation in qualification and failure analysis of semiconductor devices Final report, 28 Jun. 1967 - 10 Jun. 1969

    Get PDF
    Techniques for providing infrared data for use in failure analysis of semiconductor device

    Climate in Earth history

    Get PDF
    Complex atmosphere-ocean-land interactions govern the climate system and its variations. During the course of Earth history, nature has performed a large number of experiments involving climatic change; the geologic record contains much information regarding these experiments. This information should result in an increased understanding of the climate system, including climatic stability and factors that perturb climate. In addition, the paleoclimatic record has been demonstrated to be useful in interpreting the origin of important resources-petroleum, natural gas, coal, phosphate deposits, and many others

    The study of infrared evaluation in qualification and failure analysis of semiconductor devices Interim progress report, 28 Apr. - 28 Jul. 1968

    Get PDF
    Infrared display techniques and acceptance criteria for microcircuit qualification and semiconductor device failure analysi

    Thermal neutron image intensifier tube provides brightly visible radiographic pattern

    Get PDF
    Vacuum-type neutron image intensifier tube improves image detection in thermal neutron radiographic inspection. This system converts images to an electron image, and with electron acceleration and demagnification between the input target and output screen, produces a bright image viewed through a closed circuit television system
    • …
    corecore