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881.
Maria Merces Marques C. Costa F. Lemos F. Ram?a Ribeiro A. R. Dias 《Reaction Kinetics and Catalysis Letters》1997,62(1):9-15
In this paper we present a kinetic approach to the analysis of steady-state homogeneous Ziegler-Natta polymerization activity
data. The influence of the number of monomeric species that are coordinated to the active site on the apparent rate law is
discussed and the equations are fitted to the experimental results. 相似文献
882.
A complete parametric analysis, concerning an overall kinetic model for oscillating catalytic deep oxidation of alcohols, carbon monoxide or hydrogen, is presented. The model contains four parameters. 相似文献
883.
The kinetics of exchange of18O-containing molecular oxygen with the oxygen of an Al2(MoO4)3 catalyst has been studied in the temperature range 579–680 °C at
Torr. The activation energy of exchange is 57 kcal/mol, and the specific rate of exchange varies between 0.79×1011 and 21.2×1011 molec. cm–2 sec–1. Assumptions are made concerning the activity and selectivity of Al2(MoO4)3 with respect to oxidation reactions.
, O18, Al2(MoO4)3 579–680 °C . , 57 /, 0,79·1011 21,2·1011 O2/2.. Al2(MoO4)3 .相似文献
884.
A study is made of the catalytic condensation polymerization of polydialkylcyclosilazanes [RR'SiNH]n (n=3,4; R=CH3, C2H5; R'=C2H5, C4H9, C6H13, C9H19) in the presence of small amounts of nucleophilic reagents, to give compounds of the general type R5R6'Si6N3(NH)2 and oligomers. The reactivities of polydialkylsilazanes decrease with increase in aliphatic group chain length. 相似文献
885.
Ya. V. Rashkes Z. Sh. Faizutdinova I. A. Bessonova S. Yu. Yunusov 《Chemistry of Natural Compounds》1973,6(5):593-597
Conclusions The Claisen rearrangement of bucharaine and of the aldehyde bucharainal takes place under the conditions of mass spectrometry. At low temperatures inversion predominates and at high temperatures the anomalous rearrangement.Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR. Translated from Khimiya Prirodnykh Soedinenii, No. 5, pp. 577–583, September–October, 1970. 相似文献
886.
Conclusions The synthesis of evonoloside has been effected from cannogenol and L-rhamnose with a yield of 35%. It has been shown that when a primary alcohol group (at C19) and a secondary axial hydroxy group (at C3) are present in the aglycone, to introduce the sugar component at C3 it is desirable first to protect the primary OH group by the partial acetylation of the aglycone.Khimiya Prirodnykh Soedinenii, Vol. 5, No. 1, pp. 20–22, 1969 相似文献
887.
V. P. Sokolov N. M. Zaidman V. I. Shport Y. A. Alabuzhev 《Reaction Kinetics and Catalysis Letters》1977,6(3):329-333
Under reforming conditions, the rate of n-heptane conversion on a large Pt/Al2O3 catalyst grain, in contrast to that in the kinetic region, depends on the hydrogen to hydrocarbon mole ratio. The rate equation for the reaction on a large grain agrees well with the experimental results obtained by a gradientless method under pressure.
- , , : . , .相似文献
888.
Summary The convolution of Gaussian absorption curves using orthogonal polynomials has been studied. An absorption curve can usually be considered as a sum of Gaussian curves. The p2-convoluted log A versus curve is independent of concentration and path-length and the optimum coefficient can be used as an index of purity for absorbing compounds.
Transformation Gaußscher Absorptionskurven
Zusammenfassung Die Transformation von Gaußschen Absorptionskurven unter Verwendung von Orthogonalpolynomen wurde untersucht, denn in der Regel kann eine Absorptionskurve als Summe von Gauß-Kurven betrachtet werden. Der quadratische Polynomkoeffizient aus log A gegen ist unabhängig von Konzentration und Schichtdicke und kann als Reinheitsindex benutzt werden.相似文献
889.
A new chemiluminescence amplification reaction has been developed, which is on the coupling of the oxidation of Eosin by hydrogen peroxide under the catalysis of HRP at pH 3. 5 to the chemiluminescent reaction of luminol and hydrogen peroxide catalyzed by HRP at pH 10 to measure the activity of HRP and labelled-HRP. The detection limit of HRP is 10-10 g/mL. The lowest dilution ratio of HBsAb-HRP is 1 : 1. 8×102 and 1 : 106 for the direct method and coupled method respectively. 相似文献
890.
The roots of the plantMedicago sativa (family Fabaceae) have yielded, in addition to the medicoside G described previously, two more triterpeneglycosides, caulosaponin B and the new glycoside medicoside C. The latter has the structure of hederagenin 3-O-[-L-arabinoyranosyl-(1 2)--D-glucopyranosyl-(1 2)--L-arabinpyranoside].Institute of the Chemistry of Plant Substances, Academy of Sciences of the Uzbek SSR, Tashkent. Translated from Khimiya Prirodnykh Soedinenii, No. 6, pp. 805–808, November–December, 1985. 相似文献