316 research outputs found
ENTRETIEN HIVERNOVERNAL DU VIRUS MYXOMATEUX DANS LES TERRIERS. Myxomatose d'inoculation par la puce du lapin et myxomatose de fouissement
Joubert L., Chippaux A., Mouchet Jean, Oudar Jean. Entretien hivernovernal du virus myxomateux dans les terriers. In: Bulletin de l'Académie Vétérinaire de France tome 122 n°2, 1969. pp. 93-101
Transmission de la myxomatose par les moustiques en Camargue. RÎle prééminent de Aedes caspius et des Anopheles du groupe maculipennis
Joubert L., Oudar Jean, Mouchet Jean, Hannoun Claude. Transmission de la myxomatose par les moustiques de Camargue. RÎle prééminent de Aedes caspius et des Anopheles du groupe maculipennis (Note présentée par M. Goret) . In: Bulletin de l'Académie Vétérinaire de France tome 120 n°7, 1967. pp. 315-322
Vitamine A et infection pasteurellique expĂ©rimentale du porc. Fluctuations de lâactivitĂ© cholinestĂ©rasique Ă©rythrocytaire et plasmatique
Ruckebusch Yves, Jean-Blain Marcel, Oudar Jean, Joubert L. Vitamine A et infection Pasteurellique expĂ©rimentale du Porc. Fluctuations de lâactivitĂ© cholinestĂ©rasique Ă©rythrocytaire et plasmique. In: Bulletin de l'AcadĂ©mie VĂ©tĂ©rinaire de France tome 113 n°7, 1960. pp. 391-397
The Role of Nonequilibrium Dynamical Screening in Carrier Thermalization
We investigate the role played by nonequilibrium dynamical screening in the
thermalization of carriers in a simplified two-component two-band model of a
semiconductor. The main feature of our approach is the theoretically sound
treatment of collisions. We abandon Fermi's Golden rule in favor of a
nonequilibrium field theoretic formalism as the former is applicable only in
the long-time regime. We also introduce the concept of nonequilibrium dynamical
screening. The dephasing of excitonic quantum beats as a result of
carrier-carrier scattering is brought out. At low densities it is found that
the dephasing times due to carrier-carrier scattering is in picoseconds and not
femtoseconds, in agreement with experiments. The polarization dephasing rates
are computed as a function of the excited carrier density and it is found that
the dephasing rate for carrier-carrier scattering is proportional to the
carrier density at ultralow densities. The scaling relation is sublinear at
higher densities, which enables a comparison with experiment.Comment: Revised version with additional refs. 12 pages, figs. available upon
request; Submitted to Phys. Rev.
Laser-controlled fluorescence in two-level systems
The ability to modify the character of fluorescent emission by a laser-controlled, optically nonlinear process has recently been shown theoretically feasible, and several possible applications have already been identified. In operation, a pulse of off-resonant probe laser beam, of sufficient intensity, is applied to a system exhibiting fluorescence, during the interval of excited- state decay following the initial excitation. The result is a rate of decay that can be controllably modified, the associated changes in fluorescence behavior affording new, chemically specific information. In this paper, a two-level emission model is employed in the further analysis of this all-optical process; the results should prove especially relevant to the analysis and imaging of physical systems employing fluorescent markers, these ranging from quantum dots to green fluorescence protein. Expressions are presented for the laser-controlled fluorescence anisotropy exhibited by samples in which the fluorophores are randomly oriented. It is also shown that, in systems with suitably configured electronic levels and symmetry properties, fluorescence emission can be produced from energy levels that would normally decay nonradiatively. © 2010 American Chemical Society
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