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- CONTENTS VOLUME 284 - SECTION A No. 20 - SESSION OF MAY 23rd 1977
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- We prove that in a digraph distinct atoms are disjoint. From this follows that an arc-transitive strongly connected digraph of degree 2 d is strongly d-connected. We give also a short proof of Kameda's theorem on minimally strongly h-connected digraph.
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- In this Note we give a proof of the vanishing of homology and cohomology groups with coefficient in some G-modules where G is a finitely generated nilpotent group.
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- We define the ultraproducts of fields with an ultrametric absolute value similar to the ultraproducts of normed spaces introduced by D. Dacunha-Castelle and J. L. Krivine such that the ultraproduct of ultrametric valued fields is again an ultrametric valued field.
- We give an application to the p-adic continuous representations of the compact group Zp.
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- The rational cohomology of the discrete group GL+ (2 n, R) contains a non-zero Euler class. It is proved that the restriction of this class to any solvable subgroup is zero. As a consequence the Euler characteristic of any flat, compact manifold, without boundary, whose
1 is solvable, is zero.
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- We estud to tangential derivatives estimates obtained for W. M. Greenlee (1) and D. Huet (2).
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- By applying techniques of two preceding Notes we obtain the following characterization: let E be a complete bornological space which is separated by its dual, an open set for the "Mackey-closure" topology on E, and () the space of holomorphic complex valued functions on endowed with the topology of uniform convergence on the strictly compact sets of ; then () is nuclear if and only if the bornology of the strictly compact sets on E is a nuclear bornology. In particular we obtain as corollaries an improvement of a result of Boland (2) and of a result of Boland and Waelbroeck [(1), p. 151].
- Combining an extension of the abstract result of minimization (4) and the study of minoration of coercive convex normal integrands (3), we minimize the associated integral functionals on every closed in local measure convex set and show that the minimizing sequences are compact for the topology duality of conjugate Orlicz spaces, including (9). After characterizing the decomposability of and we minimize the associated problem of the calculus of variations when f is strongly coercive (3), which partially extends (1), (5) and (8).
- We obtain the asymptotic distribution of eigenvalues for a general class of differential operators including the hypoelliptic ones.
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- We prove a local existence theorem for multivalued differential equations with upper semi-continuous and compact convex-valued right hand side dx/dt (t, x). The multifunction is defined on the graph of another multifunction We assume to have a locally compact graph, and to be "tangent" to in some sense.
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- We prove that for birth-and-death processes on the real line with nearest particle interaction, the following two conditions guarantee the uniqueness of the solutions to the martingale problem with initial condition:
- (i) the accumulation points of the initial configuration are exactly + and - ;
- (ii) the birth rate and the death rate are both uniformly bounded.
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- The purpose of this Note is to introduce a class of vector-valued amarts for which almost sure strong convergence is obtained. All martingales, all uniform potentials, all quasi-martingales as well as almost sure strongly convergent sequences of random variables dominated by an integrable function belong to this class.
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- This paper is concerned with the problem of parameter estimation in the classical continuous time linear model of stochastic control. It is shown, under some assumptions, that the parameters are identifiable by a consistent and asymptotically normally distributed family of estimates and the problem of designing the input to enhance estimation accuracy is discussed.
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- Application to a common metallic material of an analysis process which was described by one of the authors in a previous Note.
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- We use Von Karman's equations to describe the buckling phenomenon of a thin elastic plate. We solve these equations by Galerkin's method. As soon as the load exceeds the critical load, a fundamental difficulty appears, due to a loss of coercivity. A new property of coercivity is obtained with the aid of the non-linearities and of a localization of the solutions. The approximate solutions are given by a variational principle.
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- A method of solution of these equations based on the previous determination of the characteristic values from the periodic coefficients is set up. Characteristic value variations as a function of the amplitude of a variable coefficient are plotted for some 4th order examples.
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- In a previous Note a unified newtonian model was presented, leading to an equation similar to Heckman and Sücking's. The present work is imbedded in a different geometric framework, and gives the same equation too. But it offers a better description of a matter antimatter system.
- TABLE DES ARTICLES TOME 284 - N° 20 - SERIE A - SCIENCES MATHEMATIQUES Séance du 23 mai 1977
- PARTIE SCIENTIFIQUE
- Théorie des relations
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- Combinatoire
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- Théorie des graphes
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- Algèbre
- Théorie des groupes
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- Topologie algébrique
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- Analyse mathématique
- Analyse fonctionnelle
- Equations différentielles
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- Calcul des probabilités
- Théorie des probabilités
- Mécanique des solides
- Théorie des plaques
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- Automatique
- .......... Page(s) .......... 1311
- Cosmologie
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- TABLE DES ARTICLES TOME 284 - N° 20 - SERIE A - SCIENCES MATHEMATIQUES Séance du 23 mai 1977
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- CONTENTS VOLUME 284 - SECTION B No. 20. - SESSION OF MAY 23rd 1977
- .......... Page(s) .......... 429
- We present a calculation method for predicting the boundary layer transition by using a set of transport equations. The originality of this method is its ability to determinate the onset and the development of turbulence by taking into account the main factors in a consistent manner. Another interest of this study is a detailed testing of numerical results, by means of an experimental investigation on different turbulent quantities and the intermittent characteristic of the flow during transition.
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- Cadmium sulfide polycrystalline thin films are obtained on amorphous substrate by low energy ion sputtering. The films are a few micrometers thick; they have hexagonal structure with c axis normal to the substrate. Rayleigh wave may be generated on the layered structure.
- .......... Page(s) .......... 437
- An experimental system is described which is well suited to the spectroscopic study of dense lasercreated plasmas. The space and time evolution of an atmospheric pressure helium plasma is reported.
- .......... Page(s) .......... 441
- We present an experimental method for observing a shift of far infrared lines by means of a Fourier transform spectrometer. Recording of pure rotational line compressed with argon shows an evident shift toward higher frequencies.
- .......... Page(s) .......... 445
- The study of free OH radical absorption line-width at 13.4 GHz and power saturation of the transition in two ranges of pressure (Doppler or collision broadening) gives an experimental value of collision cross-section.
- .......... Page(s) .......... 449
- .......... Page(s) .......... 449
- An absolute technique of in-depth analysis of the surface layers of a solid sample, where the particles sputtered from the surface by ion bombardment are collected in a hot chamber, then dissociated and thermally ionized, is presented and discussed. This makes it possible to overcome two essential difficulties that one encounters in secondary ion analysis, namely the strong dependence of the ion emission on the chemical bonds and the trouble due to mass interferences with polyatomic ions.
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- The active zones on the surface of the Sun reveal heliographic oscillations in longitude lasting between 20 to 30 rotations about their mean positions. These oscillations introduce a modulation of 6% in the Sun spot zone observed on the solar surface.
- TABLE DES ARTICLES TOME 284 - N° 20 - SERIE B - SCIENCES PHYSIQUES Séance du 23 mai 1977
- PARTIE SCIENTIFIQUE
- Mécanique des fluides
- Physique des plasmas
- Spectroscopie
- Spectroscopie hertzienne
- Physique des solides
- Astrophysique
- TABLE DES ARTICLES TOME 284 - N° 20 - SERIE B - SCIENCES PHYSIQUES Séance du 23 mai 1977
- .......... Page(s) .......... 429
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