409 research outputs found

    Volume, Coulomb, and volume-symmetry coefficients of nucleus incompressibility in the relativistic mean field theory with the excluded volume effects

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    The relation among the volume coefficient KK(=incompressibility of the nuclear matter), the Coulomb coefficient KcK_c, and the volume-symmetry coefficient KvsK_{vs} of the nucleus incompressibility are studied in the framework of the relativistic mean field theory with the excluded volume effects of the nucleons, under the assumption of the scaling model. It is found that K=300±50K= 300\pm 50MeV is necessary to account for the empirical values of KK, KcK_c, and KvsK_{vs}, simultaneously, as is in the case of the point-like nucleons. The result is independent on the detail descriptions of the potential of the σ\sigma-meson self-interaction and is almost independent on the excluded volume of the nucleons.Comment: PACS numbers, 21.65.+f, 21.30.+

    Compressional properties of nuclear matter in the relativistic mean field theory with the excluded volume effects

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    Compressional properties of nuclear matter are studied by using the mean field theory with the excluded volume effects of the nucleons. It is found that the excluded volume effects make it possible to fit the empirical data of the Coulomb coefficient KcK_{c} of nucleus incompressibility, even if the volume coefficient KK is small(150\sim 150MeV). However, the symmetry properties favor K=300±50K=300\pm 50MeV as in the cases of the mean field theory of point-like nucleons.Comment: PACS numbers, 21.65.+f, 21.30.+

    Incompressibility of nuclear matter, and Coulomb and volume-symmetry coefficients of nucleus incompressibility in the relativistic mean field theory

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    The volume coefficient K(=incompressibility of the nuclear matter), the Coulomb coefficient K_c, and the volume-symmetry coefficient K_{vs} of the nucleus incompressibility are studied in the framework of the relativistic mean field theory, with aid of the scaling model. It is found that K= 300\pm 50MeV is necessary to account for the empirical values of K_v, K_c, and K_{vs}, simultaneously. The result is independent on the detail descriptions of the potential of the \sigma-meson self-interaction and is almost independent of the strength of the \omega-meson self-interaction

    Experimental demonstration of quantum source coding

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    We report an experimental demonstration of Schumacher's quantum noiseless coding theorem. Our experiment employs a sequence of single photons each of which represents three qubits. We initially prepare each photon in one of a set of 8 non-orthogonal codeword states corresponding to the value of a block of three binary letters. We use quantum coding to compress this quantum data into a two-qubit quantum channel and then uncompress the two-qubit channel to restore the original data with a fidelity approaching the theoretical limit.Comment: 5 pages, 4 figure

    A Neuroendocrine Carcinoma of Undetermined Origin in a Dog

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    In this report, we describe a case of neuroendocrine carcinoma of undetermined origin in a dog. Necropsy revealed scattered small neoplastic nodules in the bilateral lungs and a small nodule in the parapancreatic lymph node. Histopathologically, both pulmonary and lymph nodal nodules showed a similar histologic pattern, with neoplastic cells being arranged in diffusely proliferating sheet-like cellular nests separated by variable amounts of fibrous septa, sometimes forming rosettes and duct-like structures. Scattered small necrotic foci and invasion to fibrous septa were typically observed. Neoplastic cells showed round to oval-shaped nuclei with prominent nucleoli and abundant eosinophilic cytoplasm that were positive for Grimelius’ silver impregnation staining and immunostaining with cytokeratin, synaptophysin, vasoactive intestinal peptide and chromogranin A, indicative of the development of a neuroendocrine carcinoma. However, judging from the distribution of tumors lacking the portion suggestive of the primary site in any organ examined, as well as no further indication of differentiation potential of neoplastic cells, this tumor has so far been diagnosed as neuroendocrine carcinoma of undetermined origin

    Quark condensate in nuclear matter based on Nuclear Schwinger-Dyson formalism

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    The effects of higher order corrections of ring diagrams for the quark condensate are studied by using the bare vertex Nuclear Schwinger Dyson formalism based on σ\sigma-ω\omega model. At the high density the quark condensate is reduced by the higher order contribution of ring diagrams more than the mean field theory or the Hartree-Fock

    Theory of ferromagnetic (III,Mn)V semiconductors

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    The body of research on (III,Mn)V diluted magnetic semiconductors initiated during the 1990's has concentrated on three major fronts: i) the microscopic origins and fundamental physics of the ferromagnetism that occurs in these systems, ii) the materials science of growth and defects and iii) the development of spintronic devices with new functionalities. This article reviews the current status of the field, concentrating on the first two, more mature research directions. From the fundamental point of view, (Ga,Mn)As and several other (III,Mn)V DMSs are now regarded as textbook examples of a rare class of robust ferromagnets with dilute magnetic moments coupled by delocalized charge carriers. Both local moments and itinerant holes are provided by Mn, which makes the systems particularly favorable for realizing this unusual ordered state. Advances in growth and post-growth treatment techniques have played a central role in the field, often pushing the limits of dilute Mn moment densities and the uniformity and purity of materials far beyond those allowed by equilibrium thermodynamics. In (III,Mn)V compounds, material quality and magnetic properties are intimately connected. In the review we focus on the theoretical understanding of the origins of ferromagnetism and basic structural, magnetic, magneto-transport, and magneto-optical characteristics of simple (III,Mn)V epilayers, with the main emphasis on (Ga,Mn)As. The conclusions we arrive at are based on an extensive literature covering results of complementary ab initio and effective Hamiltonian computational techniques, and on comparisons between theory and experiment.Comment: 58 pages, 49 figures Version accepted for publication in Rev. Mod. Phys. Related webpage: http://unix12.fzu.cz/ms
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