26,625 research outputs found

    Adsorption of atoms and molecules upon the surface of a single crystal and chemical reactions that take place upon the surface /low energy electron diffraction/ Annual progress report, 1966-1967

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    Low energy electron diffraction research of chemical interactions of gases with single crystal metal surfaces, and gas adsorption on nickel and tungsten surface

    Vanishing Hall Conductance in the Phase Glass Bose Metal at Zero Temperature

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    Motivated in part by the numerical simulations [ky,kosterlitz1,kosterlitz2] which reveal that the energy to create a defect in a gauge or phase glass scales as LθL^{\theta} with θ<0\theta<0 for 2D, thereby implying a vanishing stiffness, we re-examine the relevance of these kinds of models to the Bose metal in light of the new experiments [kapsym,armitage] which reveal that the Hall conductance is zero in the metallic state that disrupts the transition from the superconductor to the insulator in 2D samples. Because of the particle-hole symmetry in the phase glass model, we find that bosonic excitations in a phase glass background generate no Hall conductance at the Gaussian level. Furthermore, this result persists to any order in perturbation theory in the interactions. We show that when particle-hole symmetry is broken, the Hall conductance turns on with the same power law as does the longitudinal conductance. This prediction can be verified experimentally by applying a ground plane to the 2D samples

    Reflection beam isolator for submillimeter wavelengths

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    Magnetoplasma reflection beam isolators for submillimeter wave use are discussed. The basic configuration used is that of the Kerr transverse magneto-optical effect. Theoretical and experimental data at 337 microns using InSb as a plasma are given

    Functioning of inorganic/organic battery separators in silver-zinc cells

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    The results of three experimental studies related to the inorganic/organic battery separator operating mechanism are described: saponification of the plasticizer, resistivity of the simulated separators, and zincate diffusion through the separators. The inorganic/organic separator appears to be a particular example of a general class of ionic conducting films composed of inorganic fillers and/or substrates bonded together by an organic polymer containing an incompatible plasticizer that may be leached by the electrolyte. The I/O separator functions as a microporous film of varying tortuosity with essentially no specific chemical inhibition to zincate diffusion

    Making the HESP work: choices and challenges in Trent

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    Paying attention to meaning

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    Several paradigms show that responses to one event compromise responses to a second event for around 500 ms. Such effects are generally attributed to attentional capacity limitations associated with processing information in the first event. In a task in which targets could be distinguished only by their meaning, we varied the semantic relationship between distractors and targets following at different lags. Semantic relatedness alone produced a classic attentional blink. We conclude by discussing how attention theory might best accommodate these new effects

    The effect of relative plasma plume delay on the properties of complex oxide films grown by multi-laser multi-target combinatorial pulsed laser deposition

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    We report the effects of relative time delay of plasma plumes on thin garnet crystal films fabricated by dual-beam, combinatorial pulsed laser deposition. Relative plume delay was found to affect both the lattice constant and elemental composition of mixed Gd3Ga5O12 (GGG) and Gd3Sc2Ga5O12 (GSGG) films. Further analysis of the plasmas was undertaken using a Langmuir probe, which revealed that for relative plume delays shorter than ~200 µs, the second plume travels through a partial vacuum created by the first plume, leading to higher energy ion bombardment of the growing film. The resulting in-plane stresses are consistent with the transition to a higher value of lattice constant normal to the film plane that was observed around this delay value. At delays shorter than ~10 µs, plume propagation was found to overlap, leading to scattering of lighter ions from the plume and a change in stoichiometry of the resultant films

    Hollow-cylinder waveguide isolators for use at millimeter wavelengths

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    A semiconductor waveguide isolator consisting of a hollow column of a semiconductor mounted coaxially is considered in a circular waveguide in a longitudinal dc magnetic field. An elementary and physical analysis based on the excitation of plane waves in the guide and a more rigorous mode matching analysis are presented. These theoretical predictions are compared with experimental results for an InSb isolator at 94GHz and 75 K

    First steps in the oxidation of a /110/ nickel surface

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    Initial steps in oxidation of nickel surface studied using low energy back-reflection electron diffractio

    Developable images produced by X-rays using the nickel-hypophosphite system. 3: The latent image and trapped hydrogen

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    The hydrogen trapped in X-irradiated hypophosphites, phosphites, formates, oxalates, a phosphate, and some organic compounds was vacuum extracted and measured quantitatively with a mass spectrometer. After extraction, normally developable salts were found to be still developable. Thus, the latent image is not the trapped hydrogen but a species of the type HPO(-)2. The amplification factor for irradiated hypophosphites is about 100. A narrow range of wavelengths (at about 0.07 nm, 0.7 A) is responsible for the formation of the latent image
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