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231.
Anatolii V. Zhuchok 《代数通讯》2017,45(11):4960-4970
A doppelsemigroup is an algebraic system consisting of a set with two binary associative operations satisfying certain equations. Commutative dimonoids in the sense of Loday are examples of doppelsemigroups and two interassociative semigroups give rise to a doppelsemigroup. We introduce left (right) n-dinilpotent doppelsemigroups which are analogs of left (right) nilpotent semigroups of rank n considered by Schein. A free left (right) n-dinilpotent doppelsemigroup is constructed and the least left (right) n-dinilpotent congruence on a free doppelsemigroup is characterized. We also establish that the semigroups of the free left (right) n-dinilpotent doppelsemigroup are isomorphic and the automorphism group of the free left (right) n-dinilpotent doppelsemigroup is isomorphic to the symmetric group. 相似文献
232.
Loday and Ronco introduced the notion of a trioid and constructed the free trioid of rank 1. This paper is devoted to the study of congruences on trioids. We characterize the least dimonoid congruences and the least semigroup congruence on the free (commutative, rectangular) trioid. 相似文献
233.
Grebenyuk SA Perepichka IF Popov AF 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2002,58(13):2913-2923
The non-linear numerical method for evaluation of equilibrium constants and molar extinction coefficients of molecular complexes from a spectrophotometric experiment is described, which in contrast to linear models has no limitations with respect to concentrations of the components. The proposed procedure is applied to donor-acceptor interaction in solution between N-ethyl carbazole (EtCz) and 7,7,8,8-tetracyanoquinodimethane (TCNQ) or n-hexyl 2,5,7-trinitro-9-dicyanomethylenefluorene-4-carboxylate (HexDTFC) to evaluate the method and to obtain the parameters of charge transfer complexes (CTCs) formation. Association constants (K) and molar extinction coefficients (epsilon) of CTCs derived from non-linear approach (EtCz-TCNQ: K = 2.49+0.19 M(-1); epsilon = 2950 +/- 160 M(-1) cm(-1). EtCz-HexDTFC: K = 12.1 +/- 0.3 M(-1); epsilon = 1335 +/- 24 M(-1) cm(-1)) are close to that from linear models but show lower standard errors in parameter estimations. 相似文献
234.
Alexander V. Belyakov Kirill O. Nikolaenko Alexander A. Oskorbin Anatolii N. Rykov Igor F. Shishkov 《Molecular physics》2013,111(14):1850-1857
ABSTRACTThe molecular structure of 1-methylisatin (1) has been studied by gas-phase electron diffraction (GED) and quantum chemical computation up to the coupled cluster (CCSD(T)) level of theory. The semiexperimental equilibrium structure (Cs point group symmetry) has been determined from the GED data taking into account anharmonic vibrational corrections calculated in curvilinear coordinates with the B2PLYP force field. To observe fine structural effects due to the presence of different kinds of substituents, the accurate molecular structures of isatin (2) and 5-fluoroisatin (3) were also computed at the CCSD(T) level. The (O=)C–C(=O) carbon–carbon bonds of the pyrroline moiety in 1–3 are found to be remarkably longer than the typical single C–C bond. The electron donating methyl group causes a decrease of the C?N?C angle and an elongation of the N?C bond lengths in the pyrroline ring by 0.7° and up to 0.008?Å, respectively, whereas the electron withdrawing fluorine atom increases the ipso CCC angle by 2.5° in comparison to that in unsubstituted isatin. 相似文献
235.
Anatolii Kraitchinskii Mykola Kras'ko Volodymyr Neimash Vasul Voitovych Volodymyr Makara 《辐射效应与固体损伤》2013,168(6):445-450
The processes of radiation defect formation in Si with 1 MeV electron irradiation in the temperature range 100–633 K have been investigated. It is established that the generation efficiency of vacancies λV increases with temperature, then starts to saturate at temperatures of 250 K and finally stays constant at T>300 K. It is shown that at high temperatures, the λV dependence can be caused by the additional scattering of “hot” interstitial atoms on acoustical and optical phonons, the numbers of which increase with the temperature. An explanation, based on the creation of quasi-molecule of “hot” interstitial and lattice atoms, is proposed. 相似文献
236.
Arc vacuum deposition of nitride coatings in the Ti-Si-N system is carried out in an argonnitrogen mixture with variable gas concentration ratios. The resulting condensates are studied by fractographic analysis, X-ray diffraction analysis, and high-resolution scanning electron microscopy. Studied also are the elemental composition and microhardness of the condensates. At gas mixture pressure p > 5 × 10?3 Torr, conditions are found under which the hardness of the condensates is maximal, and the dependence of the hardness on the argon percentage in the mixture is obtained. At an argon percentage of 8–12%, the hardness of the coatings reaches 50 GPa. This value is 1.7 times higher than the hardness of coatings obtained in a nitrogen atmosphere. This superhard state is explained by the nanometer size (25–30 nm) of nitride grains and a specific growing texture with a family of {100} planes that is parallel to the growth plane. Such a configuration minimizes the surface energy. Mechanisms that may increase the ionization of film-forming particles and activate chemical bonds in the presence of argon are discussed. 相似文献
237.
Alexander V. Arkhipov Oleg I. Belous Boris M. Bulgakov Anatoly I. Fisun Oleg E. Marykivskiy 《International Journal of Infrared and Millimeter Waves》2003,24(7):1133-1147
An open resonator with its constituent the barrel-shaped reflected surface is described. Millimeter wave-band oscillator and amplifier based on this resonator investigated. The power and frequency characteristics are presented. It is shown that this device can best be used as a regenerative amplifier. 相似文献
238.
Boris A. Trofimov Olga V. Petrova Vladislav N. Drichkov Igor' A. Ushakov Olga N. Kazheva Anatolii N. Chekhlov Oleg A. Dyachenko 《Tetrahedron》2006,62(17):4146-4152
2-(2-Cyano-1-ethylthioethenyl)pyrroles easy exchange their ethylthio group for hydroxyl (NaOH, H2O-methanol, 40-45 °C, 1 h) to give 2-(2-cyano-1-hydroxyethenyl)pyrroles, a new family of stable enols, in 50-94% yields. The vinylic nucleophilic substitution proceeds at the double bond of both the starting pyrroles and their cyclic isomers, 3-iminopyrrolizines. X-ray structure analysis and NMR spectra show the enols to be stabilized by exceptionally strong intramolecular H-bonding. 相似文献
239.
It was found that the dependence of the light sensitivity of photographic emulsions whose solid phase was synthesized with the use of ammonia on the duration of sulfur or sulfur + gold sensitization could exhibit two maximums. The maximum observed at shorter hold times is due to light sensitivity centers that are silver in nature, which are formed by the thermal decomposition of Ag2O, and the other maximum is determined by silver sulfide or mixed silver gold sulfide centers. The effect of tetravalent iridium ions introduced during the production of AgBr grains on the chemical sensitization of photographic emulsions was revealed.Translated from Khimiya Vysokikh Energii, Vol. 39, No. 1, 2005, pp. 36–38.Original Russian Text Copyright © 2005 by Belous, Zhukov, Sviridova. 相似文献
240.
Pomogailo Anatolii D. Dzhardimalieva Gulzhian I. Rozenberg Aleksander S. Muraviev Dmitri N. 《Journal of nanoparticle research》2003,5(5-6):497-519
The kinetic peculiarities of the thermal transformations of unsaturated metal carboxylates (transition metal acrylates and maleates as well as their cocrystallites) and properties of metal-polymer nanocomposites formed have been studied. The composition and structure of metal-containing precursors and the products of the thermolysis were identified by X-ray analysis, optical and electron microscopy, magnetic measurements, EXAFS, IR and mass spectroscopy. The thermal transformations of metal-containing monomers studied are the complex process including dehydration, solid phase polymerization, and thermolysis process which proceed at varied temperature ranges. At 200–300°C the rate of thermal decay can be described by first-order equations. The products of decompositions are nanometer-sized particles of metal or its oxides with a narrow size distribution (the mean particle diameter of 5–10nm) stabilized by the polymer matrix. 相似文献