Search results for "copie"
showing 3 items of 113 documents
Spectroscopie des hexafluorures à nombre impair d'électrons
1995
From a theoretical point of view, a tensorial formalism adapted to the study of molecules or octahedral ions with a half-integer angular momentum has been developed for the first time. We have used here the method of projective representations, more consistent than that of double groups. A complete set of coupling coefficients and formulas, as well as the corresponding computing programs have been elaborated. This has firstly allowed to write a simple model describing the vibronic structure of colored hexafluorides. Then, somme applications of this formalism to the study of rovibronic couplings of XY6 molecules in a fourfold degenerate electronic state have been considered, especially conce…
Nutrition et protection de la vigne par la symbiose mycorhizienne à arbuscule
2021
National audience; La vigne, comme la majorité des espèces de plante d’intérêt agronomique, forme une symbiosemutualiste avec les Champignons Mycorhiziens à Arbuscules (CMA). En contrepartie deproduits issus de la photosynthèse, les CMA soutiennent leur(s) plante(s) hôte(s) dansl’acquisition de nutriments et la lutte contre leur(s) pathogène(s). En tant que biofertilisants, cessymbiontes obligatoires représentent une alternative de choix à l’égard des pratiques agricolesconventionnelles pour le développement d’une agriculture, et notamment d’une viticulturedurable. Les échanges entre les deux partenaires sont permis par la mise en place de structuresfongiques spécialisées appelées arbuscule…
Etude en champ proche et champ lointain de surfaces métalliques : apport des microscopies à sonde locale à l'étude des étalons de masse
2005
Among the international system of units (SI) the kilogram is the only one which is still defined by a material artefact, the international prototype of the platinum iridium kilogram. The instability of mass standards is one of the major concerns of national metrology institutes and the subject of numerous studies. Interest in microscopic studies of surface quality of a mass has grown, as it is well known that surface roughness is a factor in determining the long-term stability of mass standards. This thesis is devoted to the study in near field and far field for determining the topography and roughness of metallic surfaces, in related with different institute, national and international met…