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71.
Mátyás Bognár 《Acta Mathematica Hungarica》2004,102(1-2):37-84
The following generalization of the Hahn-Mazurkiewicz theorem is proved: Let (E,e) be a locally compact locally connected metric space. Let M be a continuum in this space and let d,e∈ M. Then there is a continuous mapping f: [0,1]→E such that f(0) = d, f(1)= e and M⊂f([0,1]). Also some corollaries of this theorem are proved. 相似文献
72.
Helga Fetter Berta Gamboa de Buen Jesús García-Falset 《Journal of Mathematical Analysis and Applications》2003,285(2):444-455
We consider a family of spaces wider than r-UNC spaces and we give some fixed point results in the setting of these spaces. 相似文献
73.
Pavol Brunovsky Geneviève Raugel 《Journal of Dynamics and Differential Equations》2003,15(2-3):571-658
We prove that for damped hyperbolic equations the Morse-Smale property (hyperbolicity of equilibria and transversal intersection of stable and unstable manifolds) is generic. More precisely, we prove that in an appropriate functional space of nonlinear terms in the equation, the set of functions for which the latter has the Morse-Smale property is residual, i.e., it is a countable intersection of open dense sets. The result extends a similar result proved in [1] for reaction diffusion equations. However, because of the absence of knowledge about nodal sets of polutions new ideas were needed in the proof. 相似文献
74.
We derive the incompressible and compressible k–ε model for locally homogeneous turbulence. The model is rigorously derived on formal mathematical grounds using the MPP modelling technique. This lets us calculate by either analytical or numerical means the closure constants of the model. To cite this article: T. Chacón Rebollo, D. Franco Coronil, C. R. Acad. Sci. Paris, Ser. I 337 (2003). 相似文献
75.
Michèle Audin 《manuscripta mathematica》2007,124(4):533-550
In this paper, we investigate symplectic manifolds endowed with a Morse–Bott function with only two critical submanifolds,
one of which is Lagrangian while the other one is symplectic. 相似文献
76.
Hydrogels of N‐vinylimidazole (VI) and sodium styrenesulfonate (SSS) were synthesized in aqueous solution by radical crosslinking copolymerization with N,N′‐methylene‐bis(acrylamide) as crosslinker. Swelling in several saline solutions was measured for hydrogel samples synthesized with different comonomer concentrations (CT = 10, 25, or 40%) and with SSS mole fractions covering a broad range (fSSS = 0–0.7), while the crosslinker ratio was 2 wt % in all cases. The degree of swelling in aqueous solution with a specific ionic strength (μ), plotted versus the SSS composition of the feed, shows a minimum for any set of samples synthesized with a fixed CT. The dependence of swelling on μ shows both polyelectrolyte (fSSS beyond the minimum) and antipolyelectrolyte behaviors (in the low fSSS limit). It was found that the nonGaussian factor of the crosslinking density and the polymer‐solvent interaction parameter increase with fSSS for any CT. Moreover, in the low fSSS limit, the osmotic swelling pressure is governed not only by the ionic contribution, but also by the polymer‐solvent mixing and, the concentration of mobile counterions inside the gel is not proportional to the net fixed charge but to the addition of cationic and anionic side groups, what discards the formation of ionic pairs. The antipolyelectrolyte effect is interpreted as due to the increasing protonation of VI as μ goes up. © 2007 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 45: 1683–1693, 2007 相似文献
77.
Details are given of a new method allowing an exact calculation of the spontaneous magnetization in the corner as well as along the edge at an arbitrary distance of the corner for a rectangular planar Ising ferromagnet. 相似文献
78.
Jesús M. Velásquez Bermúdez 《Annals of Operations Research》2002,117(1-4):21-31
This document presents theoretical considerations about the solution of dynamic optimization problems integrating the Benders Theory, the Dynamic Programming approach and the concepts of Control Theory. The so called Generalized Dual Dynamic Programming Theory (GDDP) can be considered as an extension of two previous approaches known as Dual Dynamic Programming (DDP): The first is the work developed by Pereira and Pinto [3–5], which was revised by Velásquez and others [8,9]. The second is the work developed by Read and others [2,6,7]. 相似文献
79.
The n-dimensional cube Qn is the graph whose vertices are the subsets of {1,…n}, with two vertices adjacent if and only if their symmetric difference is a singleton. Clearly Qn has diameter and radious n. Write M = n2n-1 = e(Qn) for the size of Qn. Let Q = (Qt)oM be a random Qn-process. Thus Qt is a spanning subgraph of Qn of size t, and Qt is obtained from Qt–1 by the random addition of an edge of Qn not in Qt–1, Let t(k) = τ(Q;δ?k) be the hitting time of the property of having minimal degree at least k. We show that the diameter dt = diam (Qt) of Qt in almost every Q? behaves as follows: dt starts infinite and is first finite at time t(1), it equals n + 1 for t(1) ? t(2) and dt, = n for t ? t(2). We also show that the radius of Qt, is first finite for t = t(1), when it assumes the value n. These results are deduced from detailed theorems concerning the diameter and radius of the almost surely unique largest component of Qt, for t = Ω(M). © 1994 John Wiley & Sons, Inc. 相似文献
80.
Philip T. Keenan 《Numerical Algorithms》1994,7(2):269-293
We describe a new family of discrete spaces suitable for use with mixed methods on certain quadrilateral and hexahedral meshes. The new spaces are natural in the sense of differential geometry, so all the usual mixed method theory, including the hybrid formulation, carries over to these new elements with proofs unchanged. Because transforming general quadrilaterals into squares introduces nonlinearity and because mixed methods involve the divergence operator, the new spaces are more complicated than either the corresponding Raviart-Thomas spaces for rectangles or corresponding finite element spaces for quadrilaterals. The new spaces are also limited to meshes obtained from a rectangular mesh through the application of a single global bilinear transformation. Despite this limitation, the new elements may be useful in certain topologically regular problems, where initially rectangular grids are deformed to match features of the physical region. They also illustrate the difficulties introduced into the theory of mixed methods by nonlinear transformations. 相似文献