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81.
This paper proposes a new robust chaotic system of three-dimensional
quadratic autonomous ordinary differential equations by introducing
an exponential quadratic term. This system can display a
double-scroll chaotic attractor with only two equilibria, and can be
found to be robust chaotic in a very wide parameter domain with
positive maximum Lyapunov exponent. Some basic dynamical properties
and chaotic behaviour of novel attractor are studied. By numerical
simulation, this paper verifies that the three-dimensional system
can also evolve into periodic and chaotic behaviours by a constant
controller. 相似文献
82.
Machiel Van Frankenhuysen 《Journal of Number Theory》2002,95(2):289-302
Following Elkies (Internat. Math. Res. Notices7 (1991) 99-109) and Bombieri (Roth's theorem and the abc-conjecture, preprint, ETH Zürich, 1994), we show that the ABC conjecture implies the one-dimensional case of Vojta's height inequality. The main geometric tool is the construction of a Belyǐ function. We take care to make explicit the effectivity of the result: we show that an effective version of the ABC conjecture would imply an effective version of Roth's theorem, as well as giving an (in principle) explicit bound on the height of rational points on an algebraic curve of genus at least two. 相似文献
83.
Mohammed Moussaoui Alberto Seeger 《Transactions of the American Mathematical Society》1999,351(9):3687-3711
The purpose of this work is twofold: on the one hand, we study the second-order behaviour of a nonsmooth convex function defined over a reflexive Banach space . We establish several equivalent characterizations of the set , known as the second-order subdifferential of at relative to . On the other hand, we examine the case in which is the functional integral associated to a normal convex integrand . We extend a result of Chi Ngoc Do from the space to a possible nonreflexive Banach space . We also establish a formula for computing the second-order subdifferential .
84.
从粒子一转子模型分析了奇A核K=1/2带的带交叉.脱耦合项的出现可引起回弯频率异常.在[541]↓的情况下,造成的回弯推迟可与实验观测值相比拟. 相似文献
85.
设k,r分别是自然数和非零整数,Jk(n)是Jordan函数.文[3]求出了和式∑n≤xJrk(n)的渐近公式.以E(x;k,r)表示该公式中的误差项,本文研究了E(x;k,r)的算术均值和积分均值 相似文献
86.
87.
Yao-junYe 《应用数学学报(英文版)》2004,20(1):93-100
In this paper we show the decay of solutions to the initial-boundary value problem for somenonlinear hyperbolic equation with a nonlinear dissipative term,by using a difference inequality. 相似文献
88.
Claude Ederer Matej Komelj James W. Davenport Manfred Fhnle 《Journal of Electron Spectroscopy and Related Phenomena》2003,130(1-3):97-100
The magnetic dipole term T appearing in the X-ray magnetic circular dichroism (XMCD) spin sum rule can be eliminated from the analysis within the spin sum rule by angle-dependent XMCD spectroscopy if the effects of spin–orbit coupling are small so that Tx+Ty+Tz≈0. It is shown by the ab initio electron theory for the extreme case of a low-dimensional system, i.e., for a free-standing monatomic Co wire that this relation is strongly violated, indicating that the determination of T by the angle-dependent XMCD is possibly not very reliable for low-dimensional magnetic systems. 相似文献
89.
Franciszek Hugon Szafraniec 《Numerical Algorithms》2003,33(1-4):475-483
We discuss a possibility of deciding whether measures representing a moment sequence or realizing orthogonality of polynomials have atoms. This is done on the real line and in several variables. 相似文献
90.
R. G. Vishwakarma 《General Relativity and Gravitation》2001,33(11):1973-1984
Models with a dynamic cosmological term (t) are becoming popular as they solve the cosmological constant problem in a natural way. Instead of considering any ad-hoc assumption for the variation of , we consider a particular symmetry, the contracted Ricci-collineation along the fluid flow, in Einstein's theory. We show that apart from having interesting properties, this symmetry does demand to be a function of the scale factor of the Robertson-Walker metric. In order to test the consistency of the resulting model with observations, we study the magnitude-redshift relation for the type Ia supernovae data from Perlmutter et al. The data fit the model very well and require a positive non-zero and a negative deceleration parameter. The best-fitting flat model is obtained as 0 0.5 with q
0 –0.2. 相似文献