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21.
Yang Xu Christian Axt Minhang Song Reinhold Kneer Shuiqing Li 《Proceedings of the Combustion Institute》2021,38(3):4179-4188
This paper intensively investigated the ignition of turbulent coal flames in a novel fully-mixed tubular swirl burner. The Nikon D300s digital camera was used to capture the statistical ignition behavior of dispersed coal particle streams in different ambiences. Meanwhile, the combustion dynamics of individual coal particles were also recorded by means of high-speed photography. Two low-rank coal samples, Hulunbel lignite and Zhundong coal, were tested in this study. The ignition delay times of coal particles in the swirl burner were compared with those in a flat-flame burner. In contrast to previous work on a laminar flat-flame burner, the current experimental results show that the turbulent ambience significantly enhances the ignition of all coal samples, which is exceptionally pronounced under high temperature and low oxygen conditions. In addition, the sensitivity analysis suggests that both the enhanced heat and mass transfer contribute to the early ignition in turbulence. The effect of elevated mass transfer coefficient turns prominent in low oxygen fraction ambience, wherein the volatile barrier effect is suppressed by the enhanced mixing process. The combined effect of turbulence favors the shifting of ignition modes to the heterogeneous-dominant region. Last but not least, the ceased volatile flame that visualized in turbulent low oxygen ambience further confirms the important role of heterogeneous ignition. 相似文献
22.
Maria Buchweitz Gennadi Gudi Reinhold Carle Dietmar R. Kammerer Hartwig Schulz 《Journal of Raman spectroscopy : JRS》2012,43(12):2001-2007
The FT‐Raman spectra of the chloride salts of pelargonidin‐3‐glucoside, cyanidin‐3‐glucoside and delphinidin‐3‐glucoside, their structures at pH 5.0 and their interaction with aluminium and ferric ions are presented for the first time and discussed with regard to their spectroscopic response. Two marker bands at approximately 1510 and 1330/1350 cm−1 and one band at approximately 1330/1350 cm−1 were identified being characteristic for the formation of ferric and aluminium chelates, respectively, of cyanidin‐3‐glucoside and delphinidin‐3‐glucoside. In contrast, pelargonidin‐3‐glucoside, exhibiting one single hydroxyl group in the B‐ring, did not form metal chelates, which could be clearly demonstrated by missing marker bands. The formation of anthocyanin–metal chelates was also verified in model systems containing commercial sugar beet pectin and a pectic polysaccharide fraction isolated thereof, respectively. In addition, the absence of anthocyanin–metal chelates in systems prepared with citrate buffer was confirmed, and the effects of low and high methoxylated citrus pectins on chelate formation were studied. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
23.
Reinhold Baer 《Mathematische Zeitschrift》1962,79(1):344-363
Ohne Zusammenfassung 相似文献
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Reinhold Tacke Klaus Rafeiner Carsten Strohmann Ernst Mutschler Günter Lambrecht 《应用有机金属化学》1989,3(2):129-132
The synthesis of the potent and highly selective silicon-containing antimuscarinic agent o-methoxysila-hexocyclium methyl sulfate and its corresponding tertiary amine (isolated as the dihydrochloride) is described. The quarternary compound is an o-methoxy derivative of sila-hexocyclium methyl sulfate, which represents one of the tools currently used in experimental pharmacology for the subclassification of muscarinic receptors. The o-methoxy derivative, the pharmacological profile of which differs substantially from that of the nonmethoxy compound, is also recommended as a tool for the investigation of muscarinic receptor heterogeneity. 相似文献
26.
Detailed procedures (based on the respective patent literature) for the preparation of the broadspectrum fungicide flusilazole (DPX H 6573) on the laboratory scale are described using as the starting material dichloro(chloromethyl)methylsilane [CH3(ClCH2)SiCl2]. In addition, the crystal and molecular structure of flusilazole (determined by means of X-ray diffraction analysis) is described. 相似文献
27.
Zeitschrift für Physik A Hadrons and nuclei - Berechnung der Dichteverteilung als Funktion der Höhe und der Zeit in einer Lösung endlicher Höhe unter der Wirkung von Schwere und... 相似文献
28.
H. Tauber I. S. Kleiner R. Fischer W. Paulus 《Analytical and bioanalytical chemistry》1937,108(1-2):69-70
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Heinz‐Jürgen Flad Reinhold Schneider Bert‐Wolfgang Schulze 《Mathematical Methods in the Applied Sciences》2008,31(18):2172-2201
We study the asymptotic regularity of solutions to Hartree–Fock (HF) equations for Coulomb systems. To deal with singular Coulomb potentials, Fock operators are discussed within the calculus of pseudo‐differential operators on conical manifolds. First, the non‐self‐consistent‐field case is considered, which means that the functions that enter into the nonlinear terms are not the eigenfunctions of the Fock operator itself. We introduce asymptotic regularity conditions on the functions that build up the Fock operator, which guarantee ellipticity for the local part of the Fock operator on the open stretched cone ?+ × S2. This proves the existence of a parametrix with a corresponding smoothing remainder from which it follows, via a bootstrap argument, that the eigenfunctions of the Fock operator again satisfy asymptotic regularity conditions. Using a fixed‐point approach based on Cancès and Le Bris analysis of the level‐shifting algorithm, we show via another bootstrap argument that the corresponding self‐consistent‐field solutions to the HF equation have the same type of asymptotic regularity. Copyright © 2008 John Wiley & Sons, Ltd. 相似文献