Showing papers by "University of Bordeaux published in 1972"
TL;DR: In this article, two new copper III + compounds have been prepared under oxygen pressure and investigated, and the first phase LaCuO3 has a distorded rhomboedral perovskite structure (a = 5.431 ± 0.002 A ; α = 60°51′ ± 0°02′) and the second phase La2Li0.50Cu0.
197 citations
TL;DR: In this article, the V1−xNbxO2 system has been studied by X-ray diffraction as function of temperature and composition; as in earlier works, three phases are shown to exist: a monoclinic phase which has the low temperature VO2 structure, and two tetragonal phases, one having the rutile structure and the other having low temperature NbO2 structure.
63 citations
TL;DR: In this paper, a new analysis of the infrared profile of the gaseous complex CIH...O(CH 3 ) 2 is made on the basis of its temperature dependence, in the range from 90 to −50°C.
43 citations
41 citations
TL;DR: In this paper, Hartree-Fock calculations have been performed in light 4 n nuclei from 8 Be to 28 Si using central interactions, and the rms radii, static quadrupole moments and electromagnetic transition rates have been deduced exactly from the angular momentum projected wave functions obtained in a projection before variation (PBV) procedure.
38 citations
TL;DR: TeVO 4 has been prepared in two different crystalline forms with a reversible polymorphic transformation at 650°C (α β β), both crystallize in the monoclinic system, space group P2 1 c as discussed by the authors.
33 citations
TL;DR: In this article, the distribution of the d electrons on the vanadium atoms was determined in NaV2O5 and NaV 2O4F as well as in the intermediate NaV1O5−xFx solid solution.
33 citations
TL;DR: In this paper, a series of solid solutions Ca 2− x Ln x MnO 4 (Ln = Pr, Nd, Sm, Eu et Gd) in which manganese is found in both oxidation state of +III and +IV, have a structure derived from that of K 2 NiF 4.
32 citations
TL;DR: Le comportement d'autostimulation est alors mesure pendant 8 seances de 30 mn separees par des repos de meme duree, alors que le niveau normal n'est atteint que 72 hr apres l'injection chez les animaux implantes dans l'hypothalamus lateral.
31 citations
TL;DR: The magnetic transition temperatures of the pyrochlore-type nonstoichiometric iron fluorides M x FeF 3 (M = K, Rb, Cs, NH 4 ) have been determined by Mossbauer spectroscopy over the temperature range 4.2 to 295 K.
26 citations
TL;DR: Failure to form heterocaryons between non-isogenic strains in fungi results from protoplasmic disintegration that quickly follows hyphal fusion, and genetic control of this heterogenic incompatibility has been investigated especially in the Ascomycetes Neurospora crassa1 and Podospora anserina2.
Abstract: THE failure to form heterocaryons between non-isogenic strains in fungi, which has been reported for many species, results from protoplasmic disintegration that quickly follows hyphal fusion. Genetic control of this heterogenic incompatibility has been investigated especially in the Ascomycetes Neurospora crassa1 and Podospora anserina2. Cellular (or protoplasmic) incompatibility always arises from a very specific interaction between two genes. Allelic mechanisms, when antagonistic genes are allelic, are found in the two species. In Podospora anserina, however, three incompatibility mechanisms, c/d, c/e and r/v, involve genes of unlike loci3,4.
TL;DR: In this paper, a general study of angular momentum and parity conservation in the most frequent two body strong decays is made, in order to propose new tests for the determination of the spin of the decaying particle.
TL;DR: In this paper, 3,6-Bis(trimethylsilyl)-1,4-cyclohexadiene, obtained from direct disilylation of benzene in an inert atmosphere, is hydrolysed at 0-5° in a strongly basic medium to 1, 4-cycloehexadienes.
TL;DR: De telles observations chez l'homme et leur com-paraison avec les resultats de l'experimentation ani-male vont permettre d'une part de preciser le diagnostic dans les cas d'atteintes retrocochleaires, d'autre part d'appro...
Abstract: Parmi les differentes formes de reponses electro-cochleographiques que Ton peut rencontrer dans la grande variete de situations pathologiques, certaines semblent correspondre plus particulierement a une pathologie retro-labyrinthique. (Neurinomes VIII, VII — Icteres Nucleaires — Nevrites — Tumeurs cere-brales — Syndromes Neurologiques). Ce sont les reponses larges, presentant parfois un pic positif pre-coce suivi d'un potentiel d'action distordu, ou con-stituees d'une deflexion brutale negative qui peut durer plusieurs milli-secondes. Bien qu'il soit difficile de dissocier, dans ces images peripheriques, les elements purement sensoriels des elements nerveux, il semble que de telles lesions retrolabyrinthiques reten-tissent sur le fonctionnement de l'organe peripherique a ces deux niveaux.De telles observations chez l'homme et leur com-paraison avec les resultats de l'experimentation ani-male vont permettre d'une part de preciser le diagnostic dans les cas d'atteintes retrocochleaires, d'autre part d'appro...
TL;DR: In this article, the crystallographic, dielectric and nonlinear optic properties of ABCNb 5 O 15 phases (A = Ca, Sr, Ba; B = Ba, Ba, C, Na, K) are compared.
TL;DR: Les spectres infrarouges de 800 a 40 cm-1 des perovskites aluminates LAlO3 avec L = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu et quelques autres derives similaires ont ete interpretes en liaison avec la structure of ces composes, a la lumiere de l'analyse par la methode du groupe facteur as mentioned in this paper.
Abstract: Les spectres infrarouges de 800 a 40 cm-1 des perovskites aluminates LAlO3 avec L = La, Nd, Gd, Tb, Ho, Er, orthochromites LCrO3 avec L = La, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu et quelques autres derives similaires ont ete interpretes en liaison avec la structure de ces composes, a la lumiere de l'analyse par la methode du groupe facteur.Des correlations ont ete etablies entre l'evolution spectrale et la deformation cristalline de ces composes ioniques.
TL;DR: In this article, the Raman spectra of N -ethylhexabutyldistannazane (n-C 4 H 9 ) 3 Sn] 2 NC 2 H 5, where R and R′ are alkyl or phenyl groups, have been examined in the 3600-100 cm −1 region.
TL;DR: The bottom fauna of the Hurst Deep and Needles Spoil Ground showed no obvious signs of deterioration and conditions may not have changed appreciably since surveys made 92 years ago as discussed by the authors.
TL;DR: In this article, 2-Halogenoalkoxytributyltin compounds have been prepared from tributylethoxytin and 1,2-halohydrins.
TL;DR: In this article, the system trimethylchlorosilane-magnesium-hexamethylphosphotriamide reacts with α-ethylenic acid chlorides to give trisilylated products resulting from the 1,4-addition of two SiMe3 groups to the conjugated system and the substitution of the chlorine atom by a third SiMe 3 group.
TL;DR: In this paper, a mechanism for β-silylated hydrocinnamic esters (or acid) can be obtained by hydrolysis, and the mechanism for this reaction is submitted.
TL;DR: In this article, the wavelength dependence of the molecular optical anisotropy is discussed from quantum theoretical treatment and semi-empiric formulations using laser waves and their harmonics.
TL;DR: In this paper, new phases with formula MxCrF3, M being an alkali element, have been prepared and characterized: MxF3 α (M = K, Rb, Cs) isostructural with hexagonal K0.27WO3.
TL;DR: In the presence of electrophilic reagents cleavage occurs at the silicon-propargylic carbon bond of 1,3-bis(trimethylsilyl)propyne with rearrangement to an allene.
TL;DR: In this paper, the magnetic properties of the ferrimagnetic chiolithe-type phases Na 5 V 3 F 14, Na 5 Fe 3F 14, Na 5 Co 3F14, Na5 Fe 2 CoF 14, and Na5 Co3F 14 have been investigated.
TL;DR: In this paper, the protonation rate constant for the lowest triplet state of thionine has been measured as a function of temperature and hydrogen ion concentration using the technique of laser flash photolysis.
TL;DR: In this article, an extension of the cyclization reaction by use of mercury salts on arnine-containing ethylenic systems to form monospiroheterocycles was reported.
TL;DR: In this paper, the authors retrouve, dans chaque cas, les phenomenes signales dans un precedent travail, en particulier laugmentation des composes phenoliques pendant la maturation, egalement the presence d'une teneur en tanins a la veraison representant 50 p. 100 plus, des tanins presents a la maturite.
Abstract: L'evolution des anthocyanes, des tanins et des composes phenoliques totaux est suivie, de la veraison a la maturite, en 1969, 1970 et 1971, sur les cepages Merlot et Cabernet-Sauvignon, dans deux vignobles de caracteristiques differentes. On retrouve, dans chaque cas, les phenomenes signales dans un precedent travail, en particulier l'augmentation des composes phenoliques pendant la maturation, egalement la presence d'une teneur en tanins a la veraison representant 50 p. 100 et meme plus, des tanins presents a la maturite.Les conditions climatologiques influent d'une maniere preponderante sur la teneur en composes phenoliques, beaucoup plus que la nature du cepage ou les caracteristiques du vignoble. A la maturite, dans 100 g de baies, les taux d'anthocyanes varient entre 0,11 et 0,24 g et ceux des tanins entre 0,38 et 0,59 g. Les anthocyanes sont certainement les constituants du raisin qui sont les plus affectes par les conditions propres du millesime. On comprend donc l'influence des conditions climatologiques sur la couleur des vins rouges.
TL;DR: The magnetic properties of the nonstoichiometric iron fluorides MxFeF3 (M = K, Rb, Cs) have been studied in this paper, where an explanation of the evolution of the Neel temperatures is suggested on the basis of the iron oxydation state and the structural properties.