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31.
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N. N. II'chenko Yu. A. Serguchev L. G. Gorb R. B. Gutsulyak 《Theoretical and Experimental Chemistry》1996,32(1):17-19
We have investigated the mechanism of gas-phase chlorination of acetylene using anab initio quantum chemical method in a 3–21G° basis. We show that formation ofcis andtrans addition products may be connected with the appearance of carbene in the reaction medium, formed upon addition of a chlorine molecule to one of the acetylene carbon atoms. We have found that intermediate carbene may also be a source for the appearance of radicals in the reaction medium.Institute of Organic Chemistry, National Academy of Sciences of Ukraine, 5 ul. Murmanskaya, Kiev 253094, Ukraine. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 32, No. 1, pp. 17–19, January–February, 1996. Original article submitted April 6, 1995. 相似文献
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Adaptive approximation (or interpolation) takes into account local variations in the behavior of the given function, adjusts
the approximant depending on it, and hence yields the smaller error of approximation. The question of constructing optimal
approximating spline for each function proved to be very hard. In fact, no polynomial time algorithm of adaptive spline approximation can be designed and no exact
formula for the optimal error of approximation can be given. Therefore, the next natural question would be to study the asymptotic
behavior of the error and construct asymptotically optimal sequences of partitions. In this paper we provide sharp asymptotic
estimates for the error of interpolation by splines on block partitions in
\mathbbRd{\mathbb{R}^d} . We consider various projection operators to define the interpolant and provide the analysis of the exact constant in the
asymptotics as well as its explicit form in certain cases. 相似文献
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Yuliya A. Volkova Ekaterina M. Budynina Tamara S. Kuznetsova Nikolai S. Zefirov 《Tetrahedron》2008,64(16):3548-3553
A novel approach to acyclic alkyldinitronitronates using nucleophilic opening of epoxides with the trinitromethyl anion is presented. The scope and limitations of this synthetic procedure are presented. A series of highly functionalized 3,3-dinitroisoxazolidines were synthesized as mixtures of diastereomers. 相似文献
37.
Yuliya A. Kuznetsova Vladimir B. Romakh 《Applied biochemistry and biotechnology》1996,61(1-2):205-209
The prostaglandin H synthase (PGHS) reaction has been studied with syringaldazine as the electron donor. Kinetic parameters of the reaction agreed with those for commonly used electron donors. The sensitivity of the PGHS activity detection in the presence of syring aldazine increases 10 times. A sensitive spectrophotometric assay for polyunsaturated fatty acid (PUFA) detection using syringaldazine as a new electron donor has been proposed. 相似文献
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