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Tat����na Gondov�� J��n Petrovaj Peter Kutschy Zuzana ?urillov�� Aneta Salayov�� Martin Fabi��n Daniel W. Armstrong 《Chromatographia》2011,74(11-12):751-757
Direct chiral separation of the enantiomers of spirobrassinin, 1-methoxyspirobrassinin and ten novel cis- and trans-diastereoisomers of 2-amino analogs of indole phytoalexin 1-methoxyspirobrassinol methyl ether on macrocyclic glycopeptide-based chiral stationary phase (CSP) with teicoplanin (Chirobiotic T) was studied. Normal phase eluents containing n-hexane with modifiers ethanol and 2-propanol were used. The effects of mobile phase composition, structure of the analytes and temperature were investigated. Chiral resolution on teicoplanin CSP was achieved only in the case of trans-diastereoisomers. The van??t Hoff plots were found to show linear behavior in all cases. It was found that studied normal phase enantioseparations were enthalpy driven. The elution order of the enantiomers was determined in some cases. 相似文献
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Ç. B. Ãðÿçíîáa O. T. Huκumuè Ã. B. Öu÷uøáuëu К. A. БeжаПϐuиu 《Isotopes in environmental and health studies》2013,49(6):226-227
Anhand der Äquivalenz zwischen der Kaliummenge und der entsprechenden Zählrate (40K) werden Beziehungen angegeben, die es ermöglichen, die Kaliummenge zu bestimmen, deren radiometrischer Einfluβ bei verschiedenen Gesamieffektivitäten vernachlässigbar ist. Für die häufigsten Fälle von Gesamtaktivitätsmessungen von Spaltproduktgemischen mit Hilfe der β-Strahlung sind die radiometrisch vernachlässigbaren Kaliummengen für einige Nahrungsmittel angeührt. 相似文献
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The following estimate of the pth derivative of a probability density function is examined: , where hk is the kth Hermite function and Σi = 1nhk(p)(Xi) is calculated from a sequence X1,…, Xn of independent random variables having the common unknown density. If the density has r derivatives the integrated square error converges to zero in the mean and almost completely as rapidly as O(n?α) and O(n?α log n), respectively, where . Rates for the uniform convergence both in the mean square and almost complete are also given. For any finite interval they are O(n?β) and , respectively, where . 相似文献
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Recently, Gr?tzer, Gunderson and Quackenbush have characterized the spectra of finite pseudocomplemented lattices, solving a problem raised by G. Gr?tzer in his first monograph on lattice theory from 1971. In this note we discuss the tight connection between the spectra and the Glivenko congruence of finite pseudocomplemented lattices. 相似文献
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