Propriétés (Q) et (C). Variété commutante

Matrices score-position, algorithmes et propriétés

Familles de graphes de présentation finie, propriétés et applications

Surprising Properties of Centralisers in Classical Lie Algebras

Let g be a classical Lie algebra, i.e., either gl n , sp n , or son and let e be a nilpotent element of g. We study various properties of centralisers ge. The first four sections deal with rather elementary questions, like the centre of ge, commuting varieties associatedwith ge, or centralisers of commuting pairs. The second half of the paper addresses problems related to different Poisson stru...

Elaboration, étude structurale et analyse CHARDI et BVS d’une nouvelle variété β-Na9Cr(MoO4)6 de type alluaudite

The title compound, nonasodium chromium(III) hexakis[molybdate(VI)], β-Na9CrMo6O24, was prepared by solid-state reactions. This alluaudite-type structure is constituted of infinite layers formed by links between M 2O10 (M = C/Na) dimers and MoO4 tetra-hedra. The Na(+) and Cr(3+) cations are located in the same site with, respectively, 0.25 and 0.75 occupancies. The layers are connected to each ...

La variété β-NaMoO2(AsO4)

The title compound, sodium dioxidomolybdenum(VI) arsenate(V), β-NaMoO(2)AsO(4), was prepared by solid-state reaction at 953 K. In the crystal structure, the AsO(4) tetra-hedra and MoO(6) octa-hedra (both with m symmetry) share corner atoms to form a three-dimensional framework that delimits cavities parallel to [010] where disordered six-coordinated sodium cations (half-occupation) are located....