Correlations entre la conductivite ionique et la concentration en ions alcalins dans les borates de lithium vitreux

The electrical transport properties of the B₂O₃ - xLi₂O glasses have been investigated. An electrochemical approach allows to give an interpretation of the conductivity based on the carrier concentration in relation with Li₂O content. The mobility of the Li⁺ ions does not seem to depend on the composition.     

Sur l'orientation de l'acétylation des nitriles et amides coumariliques Bz-méthoxylés

The acetylation of coumarilic amides and nitriles gave slowly 5-acetylcoumarilamide and a mixture of 5-acetylcoumarilic acid, 4-acety1-2-cyanobenzofuran and 5-acetyl-2-cyanobenzofuran. Using the same conditions, the acetylation of methoxy derivatives of these amides and nitriles gave rapidly and in high yields, the corresponding ortho and para derivative with or without demethylation.     

Analogues du nor-B benzomorphane. I. Synthese des méthano-3,5 tétrahydro-2,3,4,5 1H-benzazépines et dérivés

A series of new homologous B-norbenzomorphans, the 3,5-methano-2,3,4,5-tetrahydro-lH-l- and 2-benzazepines inculding 7- and 8-intro or amino derivatives have been synthesized as potential CNS drugs.     

Etude spectroscopique du phosphate d'isaxonine sites de protonation

The ¹³ and ¹H nmr and mass spectrometry studies were performed with isaxonine phosphate. Results showed isaxonine offers two protonstion sites on the pyrimidine ring of the molecule, Moreover, the mass spectra showed a lability of the isopropyl amine bond.     

A Convenient and efficient method for the preparation of 6-Acyl-2(3H)-benzoxazolones

Benzoxazolinone derivatives have been found to exhibit various pharmacological properties and 6-acyl-2(3H)-benzoxazolones are considered as key starting materials for the preparation of these compounds. Reported here are the optimal conditions for a regioselective acylation at the 6-position of the benzoxazolinone ring. A general method leading to the expected products in excellent yields consists in using a mixture of aluminum chloride-dimethylformamide as catalyst and acid anhydrides or chlorides as acylating agents.     

Combien existe-t-il d’octaèdres dont les longueurs des arêtes sont données?

Résumé Nous montrons que, en général, il existe au plus huit octaèdres différents dont les longueurs des arêtes sont données. Nous donnons un exemple pour lequel ce nombre huit est atteint.

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We prove that, in general, there are at the most eight distinct octahedrons with given edge-lengths. We also give an example for which this number is reached.

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Logiciels de Calculus formels utilisés:Maple. CoCOA: Alessandro Giovini, Gianfranco Niesi, Department of Mathematics, University of Genova, viale Leon Battista Alberti 4, 16132 Genova, Italy.     

Microstructure and magneto-optical properties of CoMnxFe2-xO4 spinel ferrite thin films

The magneto-optical properties of Co-Mn spinel ferrite thin films vary according to the manganese content, the degree of oxidation of mangenese ions, and microstructure. Thermal treatments allow the magneto-optical performance to be increased while maintaining small crystallite size.