OPTICAL INVESTIGATION OF InGaAs-InP QUANTUM WELLS

Les propriétés optiques des puits quantiques IN0.53Ga0.47As/InP, réalisés par épitaxie aux organo-métalliques à pression atmosphérique, ont été étudiées à l'aide d'expériences de photoluminescence et d'excitation de photoluminescence. L'origine de la luminescence a été déterminée en étudiant l'influence de la température et de la puissance d'excitation. A 2 K la luminescence est excitonique, alors que, au dessus de 100 K, on observe uniquement les recombinaisons de porteurs libres. La capture est presque indépendante de l'épaisseur du puits, alors que l'efficacité rediative, très importante, augmente lorsque le puits se rétrécit.The optical properties of In0.53Ga0.47As/InP quantum wells have been investigated using photoluminescence and photoluminescence excitation techniques. The materials were grown by atmospheric pressure metalorganic vapor phase epitaxy. The nature of the luminescence has been determined by studying the PL dependence on temperature and excitation power. It is found to be mainly due to exciton recombination at 2 K and above 100 K to free carrier recombination. The capture efficiency is almost independent of well thickness whereas the radiative efficiency, which is very good, increases when well width decreases

Protection intégrée du blé tendre d'hiver. Itinéraire technique en Picardie

National audienc

Budd-Chiari syndrome due to prothrombotic disorder: mid-term patency and efficacy of endovascular stents.

Our objective was to evaluate efficacy and patency of metallic stent placement for symptomatic Budd-Chiari syndrome (BCS) due to prothrombotic disorders. Eleven patients with proved BCS due to prothrombotic disorders were referred for endovascular treatment because of refractory ascites (n=9), abdominal pain (n=8), jaundice (n=6), and/or gastrointestinal bleeding (n=4). Stents were inserted for stenosed hepatic vein (n=7), inferior vena cava (n=2), or mesenterico-caval shunt (n=2). Clinical efficacy and stent patency was evaluated by clinical and Doppler follow-up. After a mean follow-up of 21 months, 6 patients had fully patent stents without reintervention (primary stent patency: 55%). Two patients with hepatic vein stenosis had stent thrombosis and died 4 months after procedure. Restenosis occurred in 3 cases (2 hepatic vein and 1 mesenterico-caval shunt stenosis) and were successfully treated by balloon angioplasty (n=2) and addition of new stents (n=1) leading to a 82% secondary stent patency. Of 9 patients with patent stent, 7 were asymptomatic (77%) at the end of the study. Stent placement is a safe and effective procedure to control of symptomatic BCS. Prothrombotic disorder does not seem to jeopardize patency in anticoagulated patients

Description et utilisation du systeme de recueil de la fonction de sensibilite au contraste polychrome

SIGLECNRS RP 174 (222) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Ergonomie de la salle de surveillance et de conduite de la fregate anti aerienne Cassard

SIGLECNRS RP 174 (201) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Experimentation d'un anomaloscope rouge-vert a diodes electroluminescentes

SIGLEAvailable from Centre de Documentation Scientifique et Technique, CNRS, 26 rue Boyer, 75971 Paris Cedex 20 (France) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Enquete sur les perspectives d'insertion des dialogues vocaux homme-machine dans les taches de pilotage sur les avions de transports

SIGLECNRS RP 174 (219) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Enquete sur les perspectives d'utilisation de dialogues vocaux homme-machine a bord des avions de combat

SIGLECNRS RP 174 (190) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc

Etude preliminaire dans le cadre du developpement d'aides intelligentes au pilotage: formalisation de l'expertise d'un pilote de combat et maquettage d'un systeme interactif de representations operationnelles

SIGLECNRS RP 174 (184) / INIST-CNRS - Institut de l'Information Scientifique et TechniqueFRFranc