234 research outputs found
Les ressources en eau de surface de la Basse-Terre : recueil des débits moyens mensuels de l'origine des stations à 1989
Collective character of spin excitations in a system of Mn spins coupled to a two-dimensional electron gas
We have studied the low energy spin excitations in n-type CdMnTe based dilute
magnetic semiconductor quantum wells. For magnetic fields for which the
energies for the excitation of free carriers and Mn spins are almost identical
an anomalously large Knight shift is observed. Our findings suggests the
existence of a magnetic field induced ferromagnetic order in these structures,
which is in agreement with recent theoretical predictions [J. K{\"o}nig and A.
H. MacDonald, submitted Phys. Rev. Lett. (2002)]Comment: 4 figure
Prévention de la syncope chez l'homme
- Cette étude propose d'améliorer les valeurs de sensibilité et de spécificité d'un test médical de diagnostic de la syncope chez l'homme. Cette amélioration repose notamment sur l'utilisation d'un réseau de neurones
Radio emission of extensive air shower at CODALEMA: Polarization of the radio emission along the v*B vector
Cosmic rays extensive air showers (EAS) are associated with transient radio
emission, which could provide an efficient new detection method of high energy
cosmic rays, combining a calorimetric measurement with a high duty cycle. The
CODALEMA experiment, installed at the Radio Observatory in Nancay, France, is
investigating this phenomenon in the 10^17 eV region. One challenging point is
the understanding of the radio emission mechanism. A first observation
indicating a linear relation between the electric field produced and the cross
product of the shower axis with the geomagnetic field direction has been
presented (B. Revenu, this conference). We will present here other strong
evidences for this linear relationship, and some hints on its physical origin.Comment: Contribution to the 31st International Cosmic Ray Conference, Lodz,
Poland, July 2009. 4 pages, 8 figures. v2: Typo fixed, arxiv references adde
Enzymatically-synthesized xylo-oligosaccharides laurate esters as surfactants of interest
Lipase-catalyzed synthesis of xylo-oligosaccharides esters from pure xylobiose, xylotriose and xylotetraose in the presence of vinyl laurate was investigated. The influence of different experimental parameters such as the loading of lipase, the reaction duration or the use of a co-solvent was studied and the reaction conditions were optimized with xylobiose. Under the best conditions, a regioselective esterification occurred to yield a monoester with the acyl chain at the OH-4 of the xylose unit at the non-reducing end. Surface-active properties of these pure xylo-oligosaccharides fatty esters have been evaluated. They display interesting surfactant activities that differ according to the degree of polymerization (DP) of the glycone moiety. © 202
Troubles du comportement après traumatisme crânien : quels symptômes et quelles évaluations ?
Non-pharmacological treatment for behavioural troubles in brain injury patients. Review of literature
HIV-1 integrase variability and relationship with drug resistance in antiretroviral-naive and -experienced patients with different HIV-1 subtypes
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