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1.
Romanenko G. V. Fokin S. V. Bogomyakov A. S. Zueva E. M. Ovcharenko V. I. 《Journal of Structural Chemistry》2022,63(3):441-450
Journal of Structural Chemistry - The structures of Ni(II), Cu(II), and Zn(II) complexes with anions of 2,5-pyrrolyl-disubstituted nitronyl nitroxide (L1) and iminonitroxide (L2) diradicals (HL1 is... 相似文献
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Romanenko G. V. Letyagin G. A. Maryunina K. Yu. Bogomyakov A. S. Nishihara S. Inoue K. Ovcharenko V. I. 《Russian Chemical Bulletin》2020,69(8):1530-1536
Russian Chemical Bulletin - The study is concerned with structural rearrangements in the crystals of heterospin complexes Cu(hfac)2 with nitroxide radicals LR (hfac is hexafluoroacetylacetonate, LR... 相似文献
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In 1997 Lampert and Slater introduced parallel knock-out schemes, an iterative process on graphs that goes through several rounds. In each round of this process, every vertex eliminates exactly one of its neighbors. The parallel knock-out number of a graph is the minimum number of rounds after which all vertices have been eliminated (if possible). The parallel knock-out number is related to well-known concepts like perfect matchings, hamiltonian cycles, and 2-factors.We derive a number of combinatorial and algorithmic results on parallel knock-out numbers: for families of sparse graphs (like planar graphs or graphs of bounded tree-width), the parallel knock-out number grows at most logarithmically with the number n of vertices; this bound is basically tight for trees. Furthermore, there is a family of bipartite graphs for which the parallel knock-out number grows proportionally to the square root of n. We characterize trees with parallel knock-out number at most 2, and we show that the parallel knock-out number for trees can be computed in polynomial time via a dynamic programming approach (whereas in general graphs this problem is known to be NP-hard). Finally, we prove that the parallel knock-out number of a claw-free graph is either infinite or less than or equal to 2. 相似文献
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Sokolova N. P. Varand V. L. Romanenko G. V. Lisoivan V. I. Fadeeva V. P. Sheludyakova L. A. 《Russian Journal of Coordination Chemistry》2003,29(5):362-368
Two isomers with empirical formula C6H6F9O9Tb are synthesized and their structures are studied. Isomerism was found to arise due to different positions of a proton. Crystals of two isomers are isostructural and form continuous series of solid solutions with C6H6F9O9Eu. 相似文献
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An anomaly is found in the vicinity of Tmax 560$ K on electric resistance versus temperature curves for yttrium hightemperature superconductors of the 123 phase. Xray phase analysis suggests a structural phase transition in the vicinity of Tmax due to oxygen redistribution in the mobile sublattice of this compound. Investigation of samples with Y partially replaced by Ca has shown that the structural phase transition does not depend on carrier concentration in the conduction band. 相似文献
10.
V. M. Cherkasov G. Ya. Remennikov A. A. Kisilenko E. A. Romanenko 《Chemistry of Heterocyclic Compounds》1980,16(2):179-182
The corresponding σ complexes of the Meisenheimer type, viz., anions of the potassium salts of 6H-5-nitro-6-acetonylpyrimidines,
were obtained and isolated in the reaction of 5-nitro-, 5-nitro-4-methoxy-, 5-nitro-2-methoxy-, and 5-nitro-2,4-dimethoxypyrimidines
with acetone in the presence of potassium hydroxide. The structures of the complexes were proved by means of the PMR, IR,
and UV spectra. It is shown that the acetone anion in all cases adds to the methoxy-unsubstituted position of the pyrimidine
ring, whereas nucleophilic attack takes place at the C4 atom when the 2 and 4 positions are free.
See [1] for communication 1.
Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 239–242, February, 1980. 相似文献