Extended Thomas-Fermi approximation to the one-body density matrix

The one-body density matrix is derived within the Extended Thomas-Fermi approximation. This has been done starting from the Wigner-Kirkwood distribution function for a non-local single-particle potential. The links between this new approach to the density matrix with former ones available in the literature are widely discussed. The semiclassical Hartree-Fock energy at Extended Thomas-Fermi level is also obtained in the case of a non-local one-body Hamiltonian. Numerical applications are performed using the Gogny and Brink-Boeker effective interactions. The semiclassical binding energies and root mean square radii are compared with the fully quantal ones and with those obtained using the Strutinsky averaged method.Comment: 27 pages, LateX, and 2 PostScript figures, (submitted to Nucl. Phys. A

Dynamic and quasistatic trajectories in quasifission reactions and particle emission

We show that the quasifission paths predicted by the one-body dissipation dynamics, in the slowest phase of a binary reaction, follow a quasistatic path, which represents a sequence of states of thermal equilibrium at a fixed value of the deformation coordinate. This establishes the use of the statistical particle-evaporation model in the case of dynamical time-evolving systems. Pre- and post-scission multiplicities of neutrons and total multiplicities of protons and α particles in fission reactions of 63Cu+92Mo, 60Ni+100Mo, 63Cu+100Mo at 10 MeV/u and 20Ne+144,148,154Sm at 20 MeV/u are reproduced reasonably well with statistical model calculations performed along dynamic trajectories whose slow stage (from the most compact configuration up to the point where the neck starts to develop) lasts some 35×10−21 s

Theropod tracks from the Papo Seco Formation (lower Barremian, Cabo Espichel, Lusitanian Basin)

RESUMO: Descrevem-se novas pegadas de terópodes encontradas na Boca do Chapim, a norte do Cabo Espichel (Formação de Papo Seco, Barremiano inferior). Quatorze pegadas de terópodes foram identificadas na primeira camada desta formação. Foram identificados dois tipos diferentes de pegadas de terópodes, que ocorrem em diferentes áreas e níveis desta camada. O primeiro tipo, constituído por pegadas mais pequenas e com dígitos finos, atribuímos a terópodes indeterminados; o outro tipo, constituído quatro pegadas, é atribuído ao icnogénero Megalosauripus isp.. Sugere-se que foram produzidos por terópodes de tamanho médio, sobre um substrato de lama carbonatada, provavelmente num ambiente costeiro associado a uma lagoa. Estes vestígios e outros anteriormente descritos na subjacente Formação de Areia do Mastro, sugerem uma continuidade temporal dos principais grupos de dinossauros que frequentavam esta zona, durante o início do Barremiano, embora as pegadas da Formação de Papo Seco agora descritas sugiram uma maior diversificação das espécies de terópodes.ABSTRACT: New theropod tracks found in Boca do Chapim, north of Cape Espichel (Papo Seco Formation, lower Barremian) are presented. fourteen theropod tracks were identified on the lowermost bed of this formation. Two different types of theropod footprints have been identified, which occur at two different levels of this beds. The first type, consisting of smaller footprints with narrow digits, is attributed to undetermined theropod tracks; the other type, consisting of four tracks, is assigned to the ichnogenus Megalosauripus isp.. It is suggested that they were produced by medium-sized theropods, on a carbonate mud substrate, probably in a coastal environment associated with a lagoon. These tracks and others previous described in the underlying Areia do Mastro Formation, suggest a temporal continuity of the principal groups of dinosaurs that frequented this area, during the early Barremian, although the tracks of the Papo Seo Formation described in this work suggest a greater diversification of the theropod species

Division of labor in epitranscriptomics: What have we learnt from the structures of eukaryotic and viral multimeric RNA methyltransferases?

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