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Let {ø n (dμ)} be a system of orthonormal polynomials on the unit circle with respect to a measuredμ. Szegö's theory is concerned with the asymptotic behavior ofø n (dμ) when logμ′∈L 1. In what follows we will discuss the asymptotic behavior of the ratioø n (dμ 2)/ø n (dμ 1) on the unit circle whendμ 1 anddμ 2 are close in a sense (e.g.,dμ 2=gdμ 1, where g≥0 is such thatQ(e it )g(t) andQ(e it )/g(t) are bounded for a suitable polynomialQ) and μ 1 ′ >0 almost everywhere or (a somewhat weaker requirement) lim n→∞Φ n (dμ 1,0)=0 for the monic polynomial Φ n . The asymptotic behavior of the same fraction outside the unit circle was discussed in an earlier paper. 相似文献
3.
Vilmos Fülöp Alajos Kalman Rainer Beckert Jürgen Fabian 《Monatshefte für Chemie / Chemical Monthly》1989,120(6-7):561-569
Summary The action of bisimidochlorides of oxalic acid on dithiocarbamates produces 2-thioxo-3-aryl(alkyl)-4,5-diiminothiazolidines by cycloacylation. The molecular structure of 2-thioxo-3-(4-methoxyphenyl)-4,5-bis(phenylimino)-thiazolidine is confirmed by X-ray crystal structure analysis.
Zur Reaktion von Dithiocarbaminaten mit stickstoffhaltigen Derivaten der Oxalsäure
Zusammenfassung Bei der Einwirkung von Bisimidchloriden der Oxalsäure auf Dithiocarbaminate entstehen durch Cycloacylierung 2-Thioxo-3-aryl(alkyl)-4,5-diiminothiazolidine. Die Molekülstruktur von 2-Thioxo-3-(4-methoxyphenyl)-4,5-bis(phenylimino)thiazolidin wird durch Röntgenkristallstrukturanalyse bestätigt.相似文献
4.
Miklos Kertesz Yong S. Lee James J. P. Stewart 《International journal of quantum chemistry》1989,35(2):305-313
It is shown that infinite long polyacene chains may have three energetically close but structurally distinct isomers (a symmetrical, sym, form and two lower symmetry forms: one with double bonds in a trans and another isomer with double bonds in a cis pattern). The energetics is based on solid state MNDO theory. We discuss that the symmetrical form has a substantial energy gap Eg in the Hartree–Fock approach owing to exact exchange terms, which are nonlocal. Broken symmetry Hartree–Fock (HF ) solutions for polyacene are also described. An angularly distorted structure suggested earlier on Jahn–Teller grounds is found to be energetically not favorable. 相似文献
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Gary J. Van Berkel Vilmos Kertesz 《Rapid communications in mass spectrometry : RCM》2013,27(12):1329-1334
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The β-expansions, i.e., greedy expansions with respect to non-integer bases q>1, were introduced by Réenyi and then investigated
by many authors. Some years ago, Erdős, Horváth and Joó found the surprising fact that there exist infinitely many numbers
1<q<2 for which the β-expansion of 1 is the unique possible expansion with coefficients 0 or 1. Subsequently, the unique expansions
were characterized in [9] and this characterization led to the determination (in [17]) of the smallest number q having this
curious property. It is intimately related to the classical Thue-Morse sequence. Allouche and Cosnard recently proved that
this q is transcendental. The purpose of this paper is to extend the previous results for expansions in arbitrary non-integer
bases q>1. We also determine the smallest q having the corresponding uniqueness property in each case, and we prove that all
of them are transcendental. We will also obtain some probably new properties of the Thue-Morse sequence. In the last section
we answer a question concerning the existence of universal expansions, a notion introduced in [12].
This revised version was published online in June 2006 with corrections to the Cover Date. 相似文献