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381.
Dr. Yang Zhang Kamran B. Ghiassi Qingming Deng Nataliya A. Samoylova Prof. Marilyn M. Olmstead Prof. Alan L. Balch Dr. Alexey A. Popov 《Angewandte Chemie (International ed. in English)》2015,54(2):495-499
The synthesis and single‐crystal X‐ray structural characterization of the first endohedral metallofullerene to contain a heptagon in the carbon cage are reported. The carbon framework surrounding the planar LaSc2N unit in LaSc2N@Cs(hept)‐C80 consists of one heptagon, 13 pentagons, and 28 hexagons. This cage is related to the most abundant Ih‐C80 isomer by one Stone–Wales‐like, heptagon/pentagon to hexagon/hexagon realignment. DFT computations predict that LaSc2N@Cs(hept)‐C80 is more stable than LaSc2N@D5h‐C80, and suggests that the low yield of the heptagon‐containing endohedral fullerene may be caused by kinetic factors. 相似文献
382.
383.
Ludmila A. Oparina Alexander V. Artem'ev Nikita A. Kolyvanov Oksana V. Vysotskaya Nataliya A. Chernysheva Vladimir I. Smirnov Tatyana N. Borodina Nina K. Gusarova Boris A. Trofimov 《Heteroatom Chemistry》2015,26(1):72-78
Earlier unknown S‐[1‐(organosulfanyl)ethyl]‐ and S‐[1‐(organoselenyl)ethyl] dithiophosphinates were synthesized in 85–97% yields by regioselective addition of dithiophosphinic acids to diverse vinyl sulfides and selenides under mild conditions (ambient temperature, Et2O, 3 h). 相似文献
384.
Oksana O. Matvienko Maksym F. Prodanov Nikolay Yu. Gorobets Valerii V. Vashchenko Oleh M. Vovk Nataliya V. Babayevskaya Yuri N. Savin 《Colloid and polymer science》2014,292(3):707-713
The phase behavior of mixtures of poly(9-vinylcarbazol) (PVK) and CdSe/ZnS quantum dots (QDs) were studied depending on the nature of the surfactant used as QDs shell, namely, “native surfactant” (NS) originated from the QDs synthesis, and specially designed two-component interface modifiers comprising of dendritic phosphonic acids possessing alkyl- or cyano-terminal groups and hexyl phosphonic acid as a cosurfactant. It is shown, that the nature of interface modifier dramatically influence on distribution of QDs in the nanocomposite film. Thus, both the “native surfactant” and alkyl-containing dendritic interface modifiers favors to phase segregation of QDs in the resulting nanocomposites where two-dimensional aggregates are localized near-surface layer of the PVK film. In contrast, the cyano-containing dendritic interface modifier provides the homogeneous QDs distribution through the film thickness. We determined that the concentration quenching of QDs photoluminescence is observed for PVK/QD(NS) film. For PVK films containing QDs grafted with dendritic surfactants, the luminescent intensities increase vs QD concentration up to 80–85 wt%. 相似文献
385.
Vakhid A. Mamedov Nataliya A. Zhukova Victor V. Syakaev Tat'yana N. Beschastnova Milyausha S. Kadyrova Anastasiya O. Isaeva Sevil V. Mamedova Elena L. Gavrilova Shamil K. Latypov Oleg G. Sinyashin 《Journal of heterocyclic chemistry》2019,56(8):2221-2234
Facile and efficient methods for the synthesis of 3‐benzylquinoxalin‐2(1H)‐ones and thiazolo[3,4‐a]quinoxalin‐4(5H)‐ones by the reaction of the readily available 3‐(α‐chlorobenzyl)quinoxalin‐2(1H)‐ones and thiourea have been developed, with multiple roles of the latter. Possible mechanisms are discussed. These two‐step sequences can be performed in a one‐pot manner to produce the desired products in moderate to high yields. 相似文献
386.
Mikhail F. Butman Nataliya E. Kochkina Nikolay L. Ovchinnikov Karl W. Krmer 《Molecules (Basel, Switzerland)》2021,26(11)
Fibrous Ti/Ce oxide photocatalysts were prepared for the first time by a biomimetic solution process using short flax fibers (flax straw processing waste) as a biotemplate. Titanium polyhydroxy complex solutions with 3% and 5% cerium were used as precursors. Flax fibers were impregnated in an autoclave under hydrothermal conditions. Ti/Ce oxides were obtained from the biotemplate by annealing at 600 °C. The photocatalytic activity of the Ti/Ce oxides was studied by the adsorption and decomposition of the dye rhodamine B under UV irradiation. The photocatalytic decomposition of the dye was 50% and 75% faster for Ti/Ce oxides with 3% and 5% Ce, respectively, than for the analogous undoped fibrous TiO2. The morphologies, textures, and structures of the photocatalysts were studied by scanning electron microscopy, low temperature N2 adsorption/desorption, UV-Vis spectroscopy, and X-ray and XPS analytical methods. It was shown that the introduction of Ce into the precursor solution increased the surface irregularity of the Ti/Ce oxide crystallites compared to pure TiO2. This effect scaled with the Ce concentration. Ce improved the UV light absorption of the material. The Ti/Ce oxides contained Ce4+/Ce3+ pairs that played an important role in redox processes and intensified the photocatalytic activity. 相似文献
387.
Nataliya Protsakh 《Mathematical Methods in the Applied Sciences》2021,44(1):617-633
In this paper, we consider the inverse problem for second‐order semilinear ultraparabolic equation. The equation has unknown function of time variable in its minor coefficient and two unknown functions of time and spacial variables in its right‐hand side. Initial, boundary, and integral type overdetermination conditions are posed. By using the properties of the solutions of the corresponding initial‐boundary value problem and the method of successive approximations, the sufficient conditions of the existence, and the uniqueness of the solution for the inverse problem are obtained on some time interval that depends on the coefficients of the equation. 相似文献
388.
Sergiy Varvarenko Volodymyr Samaryk Nataliya Nosova Nataliia Puzko Roman Taras Ihor Tarnavchyk Andriy Voronov Ananiy Kohut Stanislav Voronov 《Macromolecular Symposia》2010,298(1):72-78
Summary: Results of a study on polymer surface modification using heterofunctional polyperoxides are presented. A prognostic model of the polymer surface modifier efficiency was developed on the basis of obtained data. It was shown that implementation of demands to the macromolecule composition during development of new peroxide-containing modifiers in combination with sufficient peroxide group reactivity increased efficiency of the polymer surface modification. 相似文献
389.
We prove the existence and uniqueness of a solution to the elliptic transmission problem in nonsmooth domains in the weighted Hölder space. The coercive estimates of the solution are given. 相似文献
390.
Vyacheslav V. Kalashnikov Gerardo A. Pérez-Valdés Asgeir Tomasgard Nataliya I. Kalashnykova 《European Journal of Operational Research》2010
A stochastic formulation of the natural gas cash-out problem is given in a form of a bilevel multi-stage stochastic programming model with recourse. After reducing the original formulation to a bilevel linear problem, a stochastic scenario tree is defined by its node events, and time series forecasting is used to produce stochastic values for data of natural gas price and demand. Numerical experiments were run to compare the stochastic solution with the perfect information solution and the expected value solutions. 相似文献