Refine
Year of publication
- 1997 (293) (remove)
Document Type
- Article (293) (remove)
Language
Has Fulltext
- yes (293)
Keywords
- Hofmannsthal, Hugo von (5)
- Expressionismus (4)
- Literatur (4)
- Nachruf (4)
- Übersetzung (4)
- Arbeitsverhältnisse (3)
- Deutschland <DDR> (3)
- Fernsehserie (3)
- New philology (3)
- male genitalia (3)
Institute
- Extern (69)
- Physik (11)
- Gesellschaftswissenschaften (10)
- Philosophie (7)
- Institut für Sozialforschung (IFS) (6)
- Medizin (5)
- Universitätsbibliothek (5)
- Biowissenschaften (2)
- Erziehungswissenschaften (1)
- Geowissenschaften (1)
After obtaining fresh material of Opatrillus puertoricellis from Puerto Rico a comparison was done with a large series of O. armasi. This latter taxon had been previously compared with Marcuzzi's original description, mainly based on his illustration of male genitalia from Jamaica reckoned to be O. puertoricensis. Genitalia from O. p. puertoricensis (from Puerto Rico) and O. armasi, proved to be quite alike. Also morphological characters of the two populations are not very distinct, offering differentiations better considered under sub specific rather than specific level. Therefore, we propose considering O. armasi Garrido and Gutierrez, 1994, as a subspecies associated with O. puertoricensis Marcuzzi, 1977. Based on the differences shown in the male genitalia of O. armasi and O. puertoricensis from Puerto Rico and Jamaica, we consider that the animals from Jamaica are different from Puerto Rico's (O. puertoricensis), and therefore constitute an undescribed species different from 0. puertoricensis.
Six species of the genus Polyplectropns are recorded from the People's Republic of China. All the species are new to science. A key to the males is given. The larva of Polyplectropns nanjingensis sp. nov. is illustrated. The phylogenetic relationships among these species and with Polyplectropns species of the New World are discussed.
We compute the vacuum polarization correction to the binding energy of nuclear matter in the Walecka model using a nonperturbative approach. We first study such a contribution as arising from a ground-state structure with baryon-antibaryon condensates. This yields the same results as obtained through the relativistic Hartree approximation of summing tadpole diagrams for the baryon propagator. Such a vacuum is then generalized to include quantum effects from meson fields through scalar-meson condensates which amounts to summing over a class of multiloop diagrams. The method is applied to study properties of nuclear matter and leads to a softer equation of state giving a lower value of the incompressibility than would be reached without quantum effects. The density-dependent effective sigma mass is also calculated including such vacuum polarization effects.
An investigation of the transition to delta matter is performed based on a relativistic mean field formulation of the nonlinear sigma and omega model. We demonstrate that in addition to the Delta-meson coupling, the occurrence of the baryon resonance isomer also depends on the nucleon-meson coupling. Our results show that for the favored phenomenological value of m* and K, the Delta isomer exists at baryon density ~ 2–3 p0 if beta=1.31 is adopted. For universal coupling of the nucleon and Delta, the Delta density at baryon density ~ 2–3 p0 and temperature ~ 0.4–0.5 fm-1 is about normal nuclear matter density, which is in accord with a recent experimental finding.
We study here hot nuclear matter in the quark meson coupling model which incorporates explicitly quark degrees of freedom, with quarks coupled to scalar and vector mesons. The equation of state of nuclear matter including the composite nature of the nucleons is calculated at finite temperatures. The calculations are done taking into account the medium-dependent bag constant. Nucleon properties at finite temperatures as calculated here are found to be appreciably different from the value at T=0.