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991.
L. E. Payne G. A. Philippin S. Vernier‐Piro 《Mathematical Methods in the Applied Sciences》2006,29(3):281-295
This paper deals with a class of semilinear parabolic problems. In particular, we establish conditions on the data sufficient to guarantee blow up of solution at some finite time, as well as conditions which will insure that the solution exists for all time with exponential decay of the solution and its spatial derivatives. In the case of global existence, we also investigate the continuous dependence of the solution with respect to some data of the problem. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献
992.
The inequalities of Hardy-Littlewood and Riesz say that certain integrals involving products of two or three functions increase under symmetric decreasing rearrangement. It is known that these inequalities extend to integrands of the form F(u1,…,um) where F is supermodular; in particular, they hold when F has nonnegative mixed second derivatives ∂i∂jF for all i≠j. This paper concerns the regularity assumptions on F and the equality cases. It is shown here that extended Hardy-Littlewood and Riesz inequalities are valid for supermodular integrands that are just Borel measurable. Under some nondegeneracy conditions, all equality cases are equivalent to radially decreasing functions under transformations that leave the functionals invariant (i.e., measure-preserving maps for the Hardy-Littlewood inequality, translations for the Riesz inequality). The proofs rely on monotone changes of variables in the spirit of Sklar's theorem. 相似文献
993.
Let $${\cal Z}$$ and X be Hausdorff real topological vector spaces and let $${\cal L}_b(X,{\cal Z})$$ be the space of continuous linear mappings from X into $${\cal Z}$$ equipped with the topology of bounded convergence. In this paper, we define the (S)+ condition for operators from a nonempty subset of X into $${\cal L}_b(X,{\cal Z})$$ and derive some existence results for vector variational inequalities with operators of the class (S)+. Some applications to vector complementarity problems are given. 相似文献
994.
M. Seliverstov A. Andreyev N. Barré H. De Witte D. Fedorov V. Fedoseyev S. Franchoo J. Genevey G. Huber M. Huyse U. Köster P. Kunz S. Lesher B. Marsh B. Roussière J. Sauvage P. Van Duppen Yu. Volkov 《Hyperfine Interactions》2006,171(1-3):225-231
Mean-square charge radii and magnetic moments have been measured for the neutron deficient lead isotopes, 182–190Pb. The measurement was performed at the ISOLDE online mass separator, using the in-source resonance ionization spectroscopy
technique. The wavelength of the first excitation step for the resonance ionization laser ion source (RILIS) was scanned over
the resonance(s) whilst the α- and γ-ray spectra from the decay of the Pb isotopes were recorded as a function of the wavelength. The isotope shift and, in the
case of odd-A isotopes, the hyperfine splitting were deduced. The rms-charge radii of the very neutron deficient Pb isotopes follow the
smooth trend of the heavier isotopes. This finding indicates a spherical shape for the lead ground states at the neutron mid-shell
(N = 104), where the excitation energy of the oblate 0+ state in the even isotopes reaches its minimum. 相似文献
995.
Roger A. Roybal 《Proceedings of the American Mathematical Society》2007,135(12):3967-3975
Using the smallest eigenvalues of Hankel forms associated with a multidimensional moment problem, we establish a condition equivalent to the existence of a reproducing kernel. This result is a multivariate analogue of Berg, Chen, and Ismail's 2002 result. We also present a class of measures for which the existence of a reproducing kernel implies indeterminacy.
996.
I.I.D.随机变量序列矩完全收敛的精确渐近性 总被引:2,自引:0,他引:2
{X,Xn;n≥1}为独立同分布的随机变量序列, EX=0,01 p/2满足E|X|r<∞,且E|X|3<∞,那么其中Z服从均值为0,方差为σ2的正态分布. 相似文献
997.
The purpose of this paper is to introduce and study systems of vector variational-like inequalities in Banach spaces. Under certain conditions, some existence results for systems of vector variational-like inequalities in Banach spaces are obtained by Kakutani–Fan–Glicksberg fixed point theorem. 相似文献
998.
999.
Litan Yan 《Mathematische Nachrichten》2003,259(1):84-98
Let X = (Xt, ?t) be a continuous local martingale with quadratic variation 〈X〉 and X0 = 0. Define iterated stochastic integrals In(X) = (In(t, X), ?t), n ≥ 0, inductively by $$ I_{n} (t, X) = \int ^{t} _{0} I_{n-1} (s, X)dX_{s} $$ with I0(t, X) = 1 and I1(t, X) = Xt. Let (??xt(X)) be the local time of a continuous local martingale X at x ∈ ?. Denote ??*t(X) = supx∈? ??xt(X) and X* = supt≥0 |Xt|. In this paper, we shall establish various ratio inequalities for In(X). In particular, we show that the inequalities $$ c_{n,p} \, \left\Vert (G ( \langle X \rangle _{\infty} )) ^{n/2} \right\Vert _{p} \; \le \; \left\Vert {\mathop \sup \limits _{t \ge 0}} \; {\left\vert I_{n} (t, X) \right\vert \over {(1+ \langle X \rangle _{t} ) ^{n/2}}} \right\Vert _{p} \; \le C_{n, p} \, \left\Vert (G ( \langle X \rangle _{\infty} )) ^{n/2} \right\Vert _{p} $$ hold for 0 < p < ∞ with some positive constants cn,p and Cn,p depending only on n and p, where G(t) = log(1+ log(1+ t)). Furthermore, we also show that for some γ ≥ 0 the inequality $$ E \left[ U ^{p}_{n} \exp \left( \gamma {U ^{1/n} _{n} \over {V}} \right) \right] \le C_{n, p, \gamma} E [V ^{n, p}] \quad (0 < p < \infty ) $$ holds with some positive constant Cn,p,γ depending only on n, p and γ, where Un is one of 〈In(X)〉1/2∞ and I*n(X), and V one of the three random variables X*, 〈X〉1/2∞ and ??*∞(X). (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
1000.
Angela Albanese 《Journal of Mathematical Analysis and Applications》2007,335(2):1259-1273
We study different qualitative properties of the semigroup generated by some degenerate differential elliptic operators on the standard simplex of Rd. Some methods are new and are based on the representation formulas of the semigroup in terms of iterates of suitable positive operators. The main result is the ultracontractivity property which is obtained in the setting of weighted Lp-spaces. We describe the asymptotic behavior of the semigroup and obtain the compactness property in the same setting and also in spaces of continuous functions. 相似文献