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71.
本文先给出Fuzy半群中极小Fuzy理想的一些代数性质,进而利用极小Fuzy理想刻划Fuzzy单半群的一些代数性质 相似文献
72.
Multi-separation, centrifugality and centripetality imply chaos 总被引:4,自引:0,他引:4
Jiehua Mai 《Transactions of the American Mathematical Society》1999,351(1):343-351
Let be an interval. need not be compact or bounded. Let be a continuous map, and be a trajectory of with or . Then there is a point such that . A point is called a centripetal point of relative to if or , and is centrifugal if or . In this paper we prove that if there exist centripetal points of in , then has periodic points of some odd () period . In addition, we also prove that if ) is multi-separated by Fix(), or there exists a centrifugal point of in , then is turbulent and hence has periodic points of all periods.
73.
Swapna GV Montelione GT 《Journal of magnetic resonance (San Diego, Calif. : 1997)》1999,137(2):437-442
Short transverse relaxation times of Calpha and Cbeta single-quantum coherences reduce the sensitivity of triple-resonance experiments involving transfers of Calpha/Cbeta or Halpha/Hbeta coherences. Multiple-quantum line-narrowing techniques improve the relaxation properties of 13C coherences, thereby increasing the sensitivity of the experiment. In the present work, we describe PFG-CBCA(CO)NH and PFG-HBHA(CO)NH experiments that utilize heteronuclear multiple-quantum coherences in a simultaneous constant-time period to obtain completely decoupled spectra with improved sensitivity. Results indicate that approximately 30% of cross peaks show an average enhancement of approximately 15% in the CBCA(CO)NH experiment. In the related HBHA(CO)NH experiment, approximately 97% of the cross peaks show an average enhancement of approximately 40%. 相似文献
74.
75.
76.
ZHANG Qiang ZHOU Jifu & LI Jiachun Institute of Mechanics Chinese Academy of Sciences Beijing 《中国科学G辑(英文版)》2005,48(4):469-484
As one of the important coherent structures in the near-wall region, turbulent burst is responsible for the production and transport of major turbulent kinetic energy and Rey- nolds stress[1]. Nearly half of turbulent kinetic energy or Reynolds stress is produced in the near-wall region, and 80% flows in outer region only contribute 20% of them. Both ejection and sweeping events contribute 60―70% of the turbulent shear stress respec- tively[2]. Recently, turbulent burst process has been foun… 相似文献
77.
David Ginzburg Dihua Jiang Stephen Rallis 《Journal of the American Mathematical Society》2004,17(3):679-722
We characterize the nonvanishing of the central value of the Rankin-Selberg -functions in terms of periods of Fourier-Jacobi type. This characterization is based on the Langlands philosophy on functoriality and on applications of invariant theory to automorphic representations. The result is the symplectic analog of the Gross-Prasad conjecture.
78.
Wave cycles, i.e. pairs of local maxima and minima, play an important role in many engineering fields. Many cycle definitions are used for specific purposes, such as crest–trough cycles in wave studies in ocean engineering and rainflow cycles for fatigue life predicition in mechanical engineering. The simplest cycle, that of a pair of local maximum and the following local minimum is also of interest as a basis for the study of more complicated cycles. This paper presents and illustrates modern computational tools for the analysis of different cycle distributions for stationary Gaussian processes with general spectrum. It is shown that numerically exact but slow methods will produce distributions in almost complete agreement with simulated data, but also that approximate and quick methods work well in most cases. Of special interest is the dependence relation between the cycle average and the cycle range for the simple maximum–minimum cycle and its implication for the range distribution. It is observed that for a Gaussian process with rectangular box spectrum, these quantities are almost independent and that the range is not far from a Rayleigh distribution. It will also be shown that had there been a Gaussian process where exact independence hold then the range would have had an exact Rayleigh distribution. Unfortunately no such Gaussian process exists.This revised version was published online in March 2005 with corrections to the cover date. 相似文献
79.
Abstract
We prove that there are non-recursive r.e. sets
A and C with A <
T
C such that for every set
.
Both authors are supported by “863” and the National
Science Foundation of China 相似文献
80.
We obtain Chern-Osserman's inequality of a complete properly immersed minimal surface in hyperbolic -space, provided the -norm of the second fundamental form of the surface is finite.