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991.
Paul W. Ayers 《Journal of Chemical Sciences》2005,117(5):441-454
The electron localization measure proposed by Becke and Edgecombe is shown to be related to the covariance of the electron
pair distribution. Just as with the electron localization function, the local covariance does not seem to be, in and of itself,
a useful quantity for elucidating shell structure. A function of the local covariance, however, is useful for this purpose.
A different function, based on the hyperbolic tangent, is proposed to elucidate the shell structure encapsulated by the local
covariance; this function also seems to work better for the electron localization measure of Becke and Edgecombe. In addition,
we propose a different measure for the electron localization that incorporates both the electron localization measure of Becke
and Edgecombe and the Laplacian of the electron density; preliminary indications are that this measure is especially good
at elucidating the shell structure in valence regions. Methods for evaluating electron localization functions directly from
the electron density, without recourse to the Kohn-Sham orbitals, are discussed. 相似文献
992.
T. Rapcsák 《Journal of Global Optimization》1997,11(2):207-217
The Fenchel problem of level sets is solved under the conditions that theboundaries of the nested family of convex sets in Rn>+1 aregiven by C3 n-dimensional differentiable manifolds and theconvex sets determine an open or closed convex set inRn+1. 相似文献
993.
Ning Zhong 《Mathematical Logic Quarterly》1998,44(3):304-316
As is well known the derivative of a computable and C1 function may not be computable. For a computable and C∞ function f, the sequence {f(n)} of its derivatives may fail to be computable as a sequence, even though its derivative of any order is computable. In this paper we present a necessary and sufficient condition for the sequence {f(n)} of derivatives of a computable and C∞ function f to be computable. We also give a sharp regularity condition on an initial computable function f which insures the computability of its derivative f′. 相似文献
994.
Partition functions of critical 2D models on a torus can be derived from their microscopic formulation and their free field representation in the continuum limit. This is worked out explicitly for theO(n) andQ-state Potts model. Forn orQ integer we recover results obtained from conformal invariance, but our procedure also extends to nonintegral values. In the latter case the expansion on characters of the Virasoro algebra involves real coefficients of either sign. The operator content of both models is discussed in detail. 相似文献
995.
We collect some new evidence for the validity of the conjecture that every totally elliptic hypergeometric series is modular invariant and briefly discuss a generalization of such series to Riemann surfaces of arbitrary genus. 相似文献
996.
黄酮甙类化合物中的酰基取代及其取代位置的确定 总被引:1,自引:1,他引:0
研究了黄酮甙类化合物的酰基取代现象,借助2 D NMR技术,举例研究了一黄酮醇三乙酰基三糖甙的结构,着重研究糖上酰基的取代位置,并归纳总结了黄酮甙类化合物中各种常见的酰基的^13 CNMR谱及其取代所产生的位移现象。 相似文献
997.
S. Srinivasan 《Proceedings Mathematical Sciences》1997,107(4):387-389
An important theorem of Shiu gives a (precise) bound for the average of values of multiplicative functions, of a certain class,
over ‘short’ intervals. Here we obtain, by simple means, the above result of same qualitative order. 相似文献
998.
In this article we prove that the basic finite Hankel transform whose kernel is the third-type Jackson q-Bessel function has only infinitely many real and simple zeros, provided that q satisfies a condition additional to the standard one. We also study the asymptotic behavior of the zeros. The obtained results are applied to investigate the zeros of q-Bessel functions as well as the zeros of q-trigonometric functions. A basic analog of a theorem of G. Pólya (1918) on the zeros of sine and cosine transformations is also given. 相似文献
999.
In this paper, we present a power penalty function approach to the linear complementarity problem arising from pricing American
options. The problem is first reformulated as a variational inequality problem; the resulting variational inequality problem
is then transformed into a nonlinear parabolic partial differential equation (PDE) by adding a power penalty term. It is shown
that the solution to the penalized equation converges to that of the variational inequality problem with an arbitrary order.
This arbitrary-order convergence rate allows us to achieve the required accuracy of the solution with a small penalty parameter.
A numerical scheme for solving the penalized nonlinear PDE is also proposed. Numerical results are given to illustrate the
theoretical findings and to show the effectiveness and usefulness of the method.
This work was partially supported by a research grant from the University of Western Australia and the Research Grant Council
of Hong Kong, Grants PolyU BQ475 and PolyU BQ493. 相似文献
1000.
M. A. Soloviev 《Theoretical and Mathematical Physics》2006,147(2):660-669
We analyze functional analytic aspects of axiomatic formulations of nonlocal and noncommutative quantum field theories. In
particular, we completely clarify the relation between the asymptotic commutativity condition, which ensures the CPT symmetry
and the standard spin-statistics relation for nonlocal fields, and the regularity properties of the retarded Green’s functions
in momentum space that are required for constructing a scattering theory and deriving reduction formulas. This result is based
on a relevant Paley-Wiener-Schwartz-type theorem for analytic functionals. We also discuss the possibility of using analytic
test functions to extend the Wightman axioms to noncommutative field theory, where the causal structure with the light cone
is replaced with that with the light wedge. We explain some essential peculiarities of deriving the CPT and spin-statistics
theorems in this enlarged framework.
__________
Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 147, No. 2, pp. 257–269, May, 2006. 相似文献