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1.
The surface buckling of a layer-reinforced medium with the layers arranged at right angles to the surface is investigated on the basis of Bolotin's theory of layered media. The critical load is determined and the buckling mode studied. By means of a simplified approach simple expressions are obtained for the critical loads corresponding to surface buckling.Moscow Power Engineering Institute. Translated from Mekhanika Polimerov, No. 4, pp. 648–654, July–August, 1973.  相似文献   

2.
This paper deals with the inversive congruential method with power of two modulusm for generating uniform pseudorandom numbers. Statistical independence properties of the generated sequences are studied based on the distribution of triples of successive pseudorandom numbers. It is shown that there exist parameters in the inversive congruential method such that the discrepancy of the corresponding point sets in the unit cube is of an order of magnitude at leastm –1/3. The method of proof relies on a detailed analysis of certain rational exponential sums.  相似文献   

3.
Structure deformations upon loading of oriented films of polycaproamide (Kapron) or polypropylene when submicroscopic cracks (dimensions of hundreds of Ångstroms) have appeared in the samples in high concentration (up to 2 · 1015 cm–3) have been studied by x-ray diffraction methods at low and large angles. It has been established that the appearance of submicro-cracks causes relieving of the regions adjacent to them along the loading axis (extent about 1000 Å) and an increase in stress in the lateral zone relative to the crack, which is manifested in an intensification of the stretching of these zones.A. F. Ioffe Physicotechnical Institute, Academy of Sciences of the USSR, Leningrad. Translated from Mekhanika Polimerov, No. 1, pp. 51–58, January–February, 1972.  相似文献   

4.
Let be an open set. We consider on Ω the competitors (U,K) for the reduced Mumford–Shah functional, that is to say the Mumford–Shah functional in which the -norm of U term is removed, where K is a closed subset of Ω and U is a function on ΩK with gradient in  . The main result of this paper is the following: there exists a constant c for which, whenever (U,K) is a quasi-minimizer for the reduced Mumford–Shah functional and B(x,r) is a ball centered on K and contained in Ω with bounded radius, the -measure of is bounded above by crN−1 and bounded below by c−1rN−1.  相似文献   

5.
In this paper we consider systems of equations which are defined by nonsmooth functions of a special structure. Functions of this type are adapted from Kojima's form of the Karush–Kuhn–Tucker conditions for C2—optimization problems. We shall show that such systems often represent conditions for critical points of variational problems (nonlinear programs, complementarity problems, generalized equations, equilibrium problems and others). Our main purpose is to point out how different concepts of generalized derivatives lead to characterizations of different Lipschitz properties of the critical point or the stationary solution set maps.  相似文献   

6.
Résumé Nous considérons un système de spins sur d . Nous prouvons l'équivalence entre premièrement une condition faible de mélange deuxièmement le contrôle du trou dans le spectre et troisièmement celui de la constante de Sobolev logarithmique pour des potentiels de Gibbs de portée non nécessairement finie. Nous en tirons des conséquences sur la vitesse de convergence des semi-groupes dansL 2 et sur la décroissance des corrélations: il n'y a pas de régime intermédiaire entre un taux algébrique ent –2d (resp. |j-k|–2d) et un taux exponentiel. Les résultats généraux sont montrés pour des spins à valeur dans une variété riemannienne compacte ou dans un espace fini.
Summary We consider a spin system on d . We prove the equivalence between first a weak mixing condition, secondly the controle of spectral gap and thirdly the controle of logarithmic Sobolev constants for non necessarily finite range Gibbs potentials. Hence we draw consequences concerning theL 2 decay to equilibrium and the correlations decay: there is no transitory rate between an algebraic decay ast –2d (resp. |j-k|–2d)and exponential decay. The general results are obtained for both continuous and discrete compact spins.
This article was processed by the authors using the LATEX style filepljour Im from Springer-Verlag  相似文献   

7.
The kinematic approach formulated in the paper is very general. The main results obtained above also remain valid for active media of a more complicated nature than the simple ones described by Eqs. (1). To construct the kinematic theory, it is necessary to know only a few phenomenological parameters such as the propagation velocity of a plane front and the critical curvature. In principle, these parameters can be calculated using the particular equations of the active medium, for example, (1).The value of the phenomenological parameters for an active medium can also be obtained experimentally. For example, for a medium with the Belousov-Zhabotinskii chemical reaction [1] the propagation velocity of a plane front is V0=2–3 mm/min, D is the diffusion coefficient for the solution and equal to D=1.8·10–5 cm2/sec, and the rotation frequency is =5 min–1. Then, as follows from (16), the critical curvature at the free end must be 70 cm–1, in good agreement with the experimental data.  相似文献   

8.
We consider the Cauchy problem for the system of semilinear damped wave equations with small initial data:
We show that a critical exponent which classifies the global existence and the finite time blow up of solutions indeed coincides with the one to a corresponding semilinear heat systems with small data. The proof of the global existence is based on the LpLq estimates of fundamental solutions for linear damped wave equations [K. Nishihara, LpLq estimates of solutions to the damped wave equation in 3-dimensional space and their application, Math. Z. 244 (2003) 631–649; K. Marcati, P. Nishihara, The LpLq estimates of solutions to one-dimensional damped wave equations and their application to compressible flow through porous media, J. Differential Equations 191 (2003) 445–469; T. Hosono, T. Ogawa, Large time behavior and LpLq estimate of 2-dimensional nonlinear damped wave equations, J. Differential Equations 203 (2004) 82–118; T. Narazaki, LpLq estimates for damped wave equations and their applications to semilinear problem, J. Math. Soc. Japan 56 (2004) 585–626]. And the blow-up is shown by the Fujita–Kaplan–Zhang method [Q. Zhang, A blow-up result for a nonlinear wave equation with damping: The critical case, C. R. Acad. Sci. Paris 333 (2001) 109–114; F. Sun, M. Wang, Existence and nonexistence of global solutions for a nonlinear hyperbolic system with damping, Nonlinear Anal. 66 (12) (2007) 2889–2910; T. Ogawa, H. Takeda, Non-existence of weak solutions to nonlinear damped wave equations in exterior domains, Nonlinear Anal. 70 (10) (2009) 3696–3701].  相似文献   

9.
We consider stochastic integrals with a parameter in the components. Inequalities for the functional norms of stochastic integrals are derived, generalizing the known inequalities of M. Emery [1] and P.-A. Meyer [2] to triples of spaces connected by the multiplication operation.Translated from Issledovaniya po Prikladnoi Matematike, Kazan', No. 14, pp. 134–143, 1987.  相似文献   

10.
Katona conjectured that if a three-graph has 3n vertices and n3+1 triples, then there are two triples whose symmetric difference is contained in a third triple. This conjecture can be considered as a natural generalization of Turán's theorem [4] for edge graphs. The aim of this note is to prove this conjecture.  相似文献   

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