47,975 research outputs found

    The Akulov-Volkov Lagrangian, Symmetry Currents and Spontaneously Broken Extended Supersymmetry

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    A generalization of the Akulov-Volkov effective Lagrangian governing the self interactions of the Nambu-Goldstone fermions associated with spontaneously broken extended supersymmetry as well as their coupling to matter is presented and scrutinized. The resulting currents associated with R-symmetry, supersymmetry and space-time translations are constructed and seen to form a supermultiplet structure.Comment: 17 pages, LaTeX; Title, abstract and introduction changes, references adde

    Radio detection of H2O in comet Bradfield (1974b)

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    Results of observations of comet Bradfield using the Haystack telescope are summarized with emphasis on the detection of the 1.35 cm emission line of water in the comet. The excitation of water and methyl cyanide in comets is briefly considered

    Literature survey of properties of synfuels derived from coal

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    A literature survey of the properties of synfuels for ground-based gas turbine applications is presented. Four major concepts for converting coal into liquid fuels are described: solvent extraction, catalytic liquefaction, pyrolysis, and indirect liquefaction. Data on full range syncrudes, various distillate cuts, and upgraded products are presented for fuels derived from various processes, including H-coal, synthoil, solvent-refined coal, donor solvent, zinc chloride hydrocracking, co-steam, and flash pyrolysis. Some typical ranges of data for coal-derived low Btu gases are also presented

    Description and catalog of ionospheric F-region data, Jicamarca Radar Observatory, November 1966 - April 1969

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    Equatorial ionospheric F-region data reduced from the Jicamarca Radar Observatory (JRO) incoherent scatter observations for particular periods is described. It lists in catalog form the times of the observations made during those periods. These F-region data include the electron concentration and the electron and ion temperatures. The data were inferred from the incoherent scatter observations of JRO

    Effect of composition and density on the ablative performance of phenolic-nylon

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    Composition and density effects on ablative performance of phenolic-nylo

    1^{1}H-NMR spin-echo measurements of the static and dynamic spin properties in λ\lambda-(BETS)2_{2}FeCl4_{4}

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    1^{1}H-NMR spin-echo measurements of the spin-echo decay M(2τ)M(2\tau) with a decay rate 1/T2T_{2} and the frequency shift Δν/ν0\Delta\nu/\nu_{0} under applied magnetic field B\mathbf{B}0_{0} = 9 T along the a-axis over a temperature range 2.0-180 K are reported for a single crystal of the organic conductor λ\lambda-(BETS)2_{2}FeCl4_{4}. It provides the spin dynamic and static properties in the paramagnetic metal (PM) and antiferromagnetic insulator (AFI) states as well as across the PM-AFI phase transition. A large slow beat structure in the spin-echo decay is observed with a typical beat frequency of ff \sim 7 kHz and it varies across the spectrum. Its origin is attributed to the 1^{1}H-1^{1}H dipole interactions rather than to the much larger dipolar field contribution from the Fe3+^{3+} electrons (spin SS = 5/2). A simple phenomenological model provides an excellent fit to the data. The dominant 1^{1}H-NMR frequency shift comes from the dipolar field from the 3d Fe3+^{3+} ions, and the Fe3+^{3+} - Fe3+^{3+} exchange interactions (J0J_{0}) (J0J_{0} includes the d-d exchange interactions through the π\pi-electrons) have a substantial effect to the local field at the proton sites expecially at low temperatures. A good fit is obtained with J0J_{0} = - 1.7 K. The data of the spin-echo decay rate 1/T2T_{2} indicates that there is a significant change in the slow fluctuations of the local magnetic field at the 1^{1}H-sites on traversing the PM to AFI phase. This evidence supports earlier reports that the PM-AFI phase transition in λ\lambda-(BETS)2_{2}% FeCl4_{4} is driven magnetically and first order.Comment: 9 pages, 10 figures, resubmitted to Phys. Rev. B in response to comments of Editor and reviewers on March 23, 200
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