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131.
In this paper, we classify the regular embeddings of arc-transitive simple graphs of order pq for any two primes p and q (not necessarily distinct) into orientable surfaces. Our classification is obtained by direct analysis of the structure of arc-regular subgroups (with cyclic vertex-stabilizers) of the automorphism groups of such graphs. This work is independent of the classification of primitive permutation groups of degree p or degree pq for p q and it is also independent of the classification of the arc-transitive graphs of order pq for p q. 相似文献
132.
Nikolai Tarkhanov 《Proceedings of the American Mathematical Society》2004,132(8):2411-2419
We show a Lefschetz fixed point formula for holomorphic functions in a bounded domain with smooth boundary in the complex plane. To introduce the Lefschetz number for a holomorphic map of , we make use of the Bergman kernel of this domain. The Lefschetz number is proved to be the sum of the usual contributions of fixed points of the map in and contributions of boundary fixed points, these latter being different for attracting and repulsing fixed points.
133.
Guowu Yao 《Proceedings of the American Mathematical Society》2004,132(8):2483-2493
Let be a sequence of locally quasiconformal harmonic maps on the unit disk with respect to the Poincaré metric. Suppose that the energy densities of are uniformly bounded from below by a positive constant and locally uniformly bounded from above. Then there is a subsequence of that locally uniformly converges on , and the limit function is either a locally quasiconformal harmonic map of the Poincaré disk or a constant. Especially, if the limit function is not a constant, the subsequence can be chosen to satisfy some stronger conditions. As an application, it is proved that every point of the space , a subspace of the universal Teichmüller space, can be represented by a quasiconformal harmonic map that is an asymptotic hyperbolic isometry.
134.
Let I = [0, 1], c
1, c
2 ∈ (0, 1) with c
1 < c
2 and f : I⊸I be a continuous map satisfying:
are both strictly increasing and
is strictly decreasing. Let A = {x ∈ [0, c
1]∣f(x) = x},
a=max A, a
1 =max(A\{a}), and B = {x ∈ [c
2, 1]∣f(x) = x}, b=minB, b
1 =min(B\{b}). Then the inverse
limit (I, f) is an arc if and only if one of the following three conditions holds:
(1) If c
1 < f (c
1) ≤ c
2 (resp. c
1 ≤ f (c
2) < c
2), then f has a single fixed point, a period two orbit,
but no points of period greater than two or f has more than one fixed point but no points of other periods, furthermore, if A≠φ and B≠φ, then f (c
2) > a (resp. f (c
1) < b).
(2) If f (c
1) ≤ c
1 (resp. f (c
2) ≥ c
2), then f has more than one fixed point, furthermore, if B≠φ and A\ {a} ≠φ, f (c
2) ≥ a or if a
1 < f (c
2) < a, f
2 (c
2) > f (c
2), (resp. f has more than one fixed point, furthermore, if A≠φ and B\{b}≠φ, f (c
1) ≤ b or if b < f (c
2) < b
1, f
2 (c
1) < f (c
1)).
(3) If f (c
1) > c
2 and f (c
2) < c
1, then f has a single fixed point, a single period two orbit lying in I\(u, v) but no points of period greater than two, where u, v ∈ [c
1, c
2] such that f (u) = c
2 and f (v) = c
1.
Supported by the National Natural Science Foundation of China (No. 19961001, No. 60334020) and Outstanding Young Scientist
Research Fund. (No. 60125310) 相似文献
135.
A rat brain protein expression map including cytosolic and enriched mitochondrial and microsomal fractions 总被引:9,自引:0,他引:9
Proteomics is a powerful tool to screen brain protein expression but the methodology is hampered by low abundance of proteins or compartmentalization or overload of high-abundance proteins. It was therefore the aim of the study to determine the expression of brain proteins by using enriched cellular subfractions and pre-electrophoretic chromatographical separation of brain homogenates. We used two-dimensional electrophoresis with subsequent matrix-assisted laser desorption/ionization (MALDI) detection and characterization of brain proteins. Subfractionation into cytosolic, mitochondrial and microsomal compartments was performed by ultracentrifugation. Pre-electrophoretic fractionation of the cytosolic fractions was carried out by ion exchange column chromatography. We detected and identified a large series of 437 proteins in rat brain and have shown proteins specific for the individual subcellular compartments. These proteins included housekeeping, signaling, cytoskeletal, intermediary metabolism, antioxidant proteins on the one and neuron and synaptosomal specific proteins on the other hand. Using fractionations of brain homogenates we were able to improve the power of the method on forming the basis for brain protein expressional studies and providing a reference map as a powerful tool for the neuroscientist. 相似文献
136.
For nonautonomous dynamical systems, the principle of inheriting local properties by global Poincaré maps is developed. Using this method, a selection criterion for systems of close competitors is found: to gain competitive advantage, it suffices to outproduce other populations with a margin. The margin factor in question remains uniformly bounded as the number of competitors in the community grows. 相似文献
137.
We study the exact multiplicity and ordering properties of positive solutions of the p-Laplacian Dirichlet problem
138.
In several complex variables, the multivariate Padé-type approximation theory is based on the polynomial interpolation of the multidimensional Cauchy kernel and leads to complicated computations. In this paper, we replace the multidimensional Cauchy kernel by the Bergman kernel function K
(z,x) into an open bounded subset of C
n
and, by using interpolating generalized polynomials for K
(z,x), we define generalized Padé-type approximants to any f in the space OL
2() of all analytic functions on which are of class L
2. The characteristic property of such an approximant is that its Fourier series representation with respect to an orthonormal basis for OL
2() matches the Fourier series expansion of f as far as possible. After studying the error formula and the convergence problem, we show that the generalized Padé-type approximants have integral representations which give rise to the consideration of an integral operator – the so-called generalized Padé-type operator – which maps every f
OL
2() to a generalized Padé-type approximant to f. By the continuity of this operator, we obtain some convergence results about series of analytic functions of class L
2. Our study concludes with the extension of these ideas into every functional Hilbert space H and also with the definition and properties of the generalized Padé-type approximants to a linear operator of H into itself. As an application we prove a Painlevé-type theorem in C
n
and we give two examples making use of generalized Padé-type approximants. 相似文献
139.
Rein van der Hout 《Journal of Differential Equations》2003,192(1):188-201
Let and be the unit disk and the unit sphere, and let be a radially symmetric harmonic map heat flow, whose singularities coincide with downward energy jumps. Then its finite time singularities are simple in the sense that precisely one harmonic sphere separates at a time. 相似文献
140.
L''. Holá 《Set-Valued Analysis》2003,11(2):133-151
Our paper studies the topology of uniform convergence on compact sets on the space of densely continuous forms (introduced by Hammer and McCoy (1997)), usco and minimal usco maps. We generalize and complete results from Hammer and McCoy (1997) concerning the space D(X,Y) of densely continuous forms from X to Y. Let X be a Hausdorff topological space, (Y,d) be a metric space and D
k
(X,Y) the topology of uniform convergence on compact sets on D(X,Y). We prove the following main results: D
k
(X,Y) is metrizable iff D
k
(X,Y) is first countable iff X is hemicompact. This result gives also a positive answer to question 4.1 of McCoy (1998). If moreover X is a locally compact hemicompact space and (Y,d) is a locally compact complete metric space, then D
k
(X,Y) is completely metrizable, thus improving a result from McCoy (1998). We study also the question, suggested by Hammer and McCoy (1998), when two compatible metrics on Y generate the same topologies of uniform convergence on compact sets on D(X,Y). The completeness of the topology of uniform convergence on compact sets on the space of set-valued maps with closed graphs, usco and minimal usco maps is also discussed. 相似文献