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981.
982.
In this paper, we prove that every graph with maximum degree six that can be embedded in a surface of nonnegative characteristic is of Class I if it does not contain a 5- or 6-cycle with a chord, which extends some known results. 相似文献
983.
In this paper, we study two different extensions of the Hausdorff operator to the multilinear case. Boundedness on Lebesgue spaces and Herz spaces is obtained. The bound on the Lebesgue space is optimal. Our results are substantial extensions of some known results on Multilinear high dimensional Hardy operator. 相似文献
984.
A high dimension predator-prey model is considered in this paper. Some novel criteria are established for the existence and global asymptotic stability of a unique equilibrium of such model. The approaches are based on fixed point theory, matrix spectral theory and Lyapunov functional. The existence and stability conditions given in terms of spectral radius of explicit matrices are better than conditions obtained by using classic norms. Finally, an example and its simulations show the feasibility of our results. 相似文献
985.
The authors obtain a holomorphic Lefschetz fixed point formula for certain non-compact “hyperbolic” Kǎihler manifolds (e.g. Kǎihler hyperbolic manifolds, bounded domains of holomorphy) by using the Bergman kernel. This result generalizes the early work of Donnelly and Fefferman. 相似文献
986.
It is proved that planar graphs with maximum degree 7 and without 5-cycles are 8-totally-colorable. 相似文献
987.
988.
989.
A simple, efficient method for oxidation of primary and secondary alcohols to the corresponding aldehydes and ketones has been developed. Using RuCl3/Et3N as catalyst, the oxidation of benzyl alcohol with oxygen could be achieved with 332 h−1 turnover frequency in the absence of solvent. The influence of versatile N‐containing additives on the catalytic efficiency has been discussed. The presence of minor water would substantially promote the catalytic efficiency, and its role in catalysis has been investigated in detail. The insensitive Hammett correlations of the substituted benzyl alcohols, the normal substrate isotope effect (kH/kD = 3.5 at 335 K), and the linear relationship between O2 pressure and turnover frequency imply that the reoxidation of the Ru(III) hydride intermediate to the active species shares the rate‐determining step with the hydride transfer in the catalytic cycle. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
990.
Recently, Kowalik, Sereni, and ?krekovski proved that planar graphs with maximum degree 9 are 10-totally colorable. This work proves that planar graphs with maximum degree 8 and without intersecting triangles are 9-totally colorable. 相似文献