438 research outputs found
Volume, Coulomb, and volume-symmetry coefficients of nucleus incompressibility in the relativistic mean field theory with the excluded volume effects
The relation among the volume coefficient (=incompressibility of the
nuclear matter), the Coulomb coefficient , and the volume-symmetry
coefficient 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 MeV is necessary to account for the empirical values of ,
, and , simultaneously, as is in the case of the point-like
nucleons. The result is independent on the detail descriptions of the potential
of the -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
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 of nucleus incompressibility, even if the volume
coefficient is small(MeV). However, the symmetry properties favor
MeV 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
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
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
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
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 - 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
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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