687 research outputs found

    Resumptive Repetition?introduction to a Universal Discourse Feature

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    When repetition is used to resume a previous topic after a digression, interruption or some other interlude, then we can call this ?resumptive repetition?. The focus of this paper introduces resumptive repetition as a leading cognitive device used for topic continuity in the environment of digressions. Resumptive repetition is an important universal discourse feature because it is a cognitive part of human language that ?wraps around? or ?encapsulates? the syntax of any language. It is one of the few features of language that transparently shows the human mind working the same way cross-linguistically in the area of topic continuity

    Isovector Channel Role of Relativistic Mean Field Models in the Neutrino Mean Free Path

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    An improvement in the treatment of the isovector channel of relativistic mean field (RMF) models based on effective field theory (E-RMF) is suggested, by adding an isovector scalar (delta) meson and using a similar procedure to the one used by Horowitz and Piekarewicz to adjust the isovector-vector channel in order to achieve a softer density dependent symmetry energy of the nuclear matter at high density. Their effects on the equation of state (EOS) at high density and on the neutrino mean free path (NMFP) in neutron stars are discussed.Comment: 20 pages, 8 figure

    Neutrino Electromagnetic Form Factors Effect on the Neutrino Cross Section in Dense Matter

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    The sensitivity of the differential cross section of the interaction between neutrino-electron with dense matter to the possibly nonzero neutrino electromagnetic properties has been investigated. Here, the relativistic mean field model inspired by effective field theory has been used to describe non strange dense matter, both with and without the neutrino trapping. We have found that the cross section becomes more sensitive to the constituent distribution of the matter, once electromagnetic properties of the neutrino are taken into account. The effects of electromagnetic properties of neutrino on the cross section become more significant for the neutrino magnetic moment mu_nu > 10^{-10} mu_B and for the neutrino charge radius R > 10^{-5} MeV^{-1}.Comment: 24 pages, 10 figures, submitted to Physical Review

    Anisotropic ferromagnetism in carbon doped zinc oxide from first-principles studies

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    A density functional theory study of substitutional carbon impurities in ZnO has been performed, using both the generalized gradient approximation (GGA) and a hybrid functional (HSE06) as exchange-correlation functional. It is found that the non-spinpolarized CZn_\mathrm{Zn} impurity is under almost all conditions thermodynamically more stable than the CO_\mathrm{O} impurity which has a magnetic moment of 2μB2\mu_{\mathrm{B}}, with the exception of very O-poor and C-rich conditions. This explains the experimental difficulties in sample preparation in order to realize d0d^{0}-ferromagnetism in C-doped ZnO. From GGA calculations with large 96-atom supercells, we conclude that two CO_\mathrm{O}-CO_\mathrm{O} impurities in ZnO interact ferromagnetically, but the interaction is found to be short-ranged and anisotropic, much stronger within the hexagonal abab-plane of wurtzite ZnO than along the c-axis. This layered ferromagnetism is attributed to the anisotropy of the dispersion of carbon impurity bands near the Fermi level for CO_{\mathrm{O}} impurities in ZnO. From the calculated results, we derive that a CO_{\mathrm{O}} concentration between 2% and 6% should be optimal to achieve d0d^{0}-ferromagnetism in C-doped ZnO.Comment: 9 pages, 7 figure

    Superheavy nuclei in relativistic effective Lagrangian model

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    Isotopic and isotonic chains of superheavy nuclei are analyzed to search for spherical double shell closures beyond Z=82 and N=126 within the new effective field theory model of Furnstahl, Serot, and Tang for the relativistic nuclear many-body problem. We take into account several indicators to identify the occurrence of possible shell closures, such as two-nucleon separation energies, two-nucleon shell gaps, average pairing gaps, and the shell correction energy. The effective Lagrangian model predicts N=172 and Z=120 and N=258 and Z=120 as spherical doubly magic superheavy nuclei, whereas N=184 and Z=114 show some magic character depending on the parameter set. The magicity of a particular neutron (proton) number in the analyzed mass region is found to depend on the number of protons (neutrons) present in the nucleus.Comment: 26 pages, REVTeX, 10 ps figures; changed conten
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