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51.
Vakhid A. Mamedov Tat′yana N. Beschastnova Nataliya A. Zhukova Aidar T. Gubaidullin Rustem A. Isanov Il′dar Kh. Rizvanov 《Tetrahedron letters》2008,49(31):4658-4660
A highly efficient, one-step, versatile method for the synthesis of tetrahydroindoles has been developed on the basis of new ring formation in the reactions of 1-(1-pyrrolidino)cyclohexene with chloropyruvates. 相似文献
52.
Nataliya V. Smorodina 《Acta Appl Math》2007,97(1-3):239-250
Let ξ(t),t∈[0,1] be a strictly stable Lévy process with the index of stability α∈(0,2). By ℘
ξ
we denote the law of ξ in the Skorokhod space
. For arbitrary ξ we construct ℘
ξ
-quasi-invariant semigroup of transformations of
. Under some nondegeneracy condition on the spectral measure of the stable process we construct ℘
ξ
-quasi-invariant group of transformations of
. In symmetric case this group is a group of the invariant transformations.
相似文献
53.
Houskova V Stengl V Bakardjieva S Murafa N Kalendova A Oplustil F 《The journal of physical chemistry. A》2007,111(20):4215-4221
Zinc sulfide (ZnS) nanoparticles were prepared by homogeneous hydrolysis of zinc sulfate and thioacetamide (TAA) at 80 degrees C. After annealing at a temperature above 400 degrees C in oxygen atmosphere, zinc oxide (ZnO) nanoparticles were obtained. The ZnS and ZnO nanoparticles were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), high-resolution transmission electron microscopy (HRTEM), selected area electron diffraction (SAED), and Brunauer-Emmett-Teller (BET)/Barrett-Joyner-Halenda (BJH) methods were used for surface area and porosity determination. The photocatalytic activity of as-prepared zinc oxide samples was determined by decomposition of Orange II dye in aqueous solution under UV irradiation of 365 nm wavelength. Synthesized ZnO were evaluated for their non-photochemical degradation ability of chemical warfare agents to nontoxic products. 相似文献
54.
Elena V. Karpova Alexander I. Boltalin Maxim A. Zakharov Nataliya I. Sorokina Yuri M. Korenev Sergei I. Troyanov 《无机化学与普通化学杂志》1998,624(4):741-744
Cu2(CF3COO)4 · 2 CH3CN ( I ) and Cu(CF3COO)2(H2O)4 ( II ) have been prepared by concentrating of acetonitrile and aqueous solutions respectively. According to X-ray data, the complex I consists of binuclear molecules with Cu–O 1.969 Å, Cu–N 2.114 Å. The Cu…Cu distance was found to be 2.766 Å, one of the longest for dimeric structures, apparently, due to the high acidity of trifluoroacetic acid. The coordination environment of Cu atom in II can be described as 4 + 2: 2 Cu–O (H2O) 1.937 Å, 2 Cu–O (CF3COO) 1.985 Å, 2 Cu–O (H2O) 2.447 Å. The mononuclear structure is stabilized by formation of two intra- and six intermolecular hydrogen bonds. 相似文献
55.
Maria Bruma Corneliu Hamciuc Elena Hamciuc Frank Mercer Nataliya Belomoina Burkhard Schulz 《Macromolecular Symposia》1997,122(1):303-311
New heterocyclic polyamides have been synthesized by solution polycondensation of aromatic diamines containing phenylquinoxaline units with diacid chlorides having both imide and hexafluoroisopropylidene (6F) groups. These polymers are soluble in polar aprotic solvents, such as N-methylpyrrolidone (NMP) or N, N-dimethylformamide (DMF), and can be cast into flexible thin films from solutions. They show high thermooxidative stability with decomposition temperatures above 400°C and glass transition temperatures in the range of 225-300°C. The polymer films exhibit good chemical resistance towards diluted acids and good electrical insulating properties with dielectric constants in the range of 3.2–3.7. 相似文献
56.
Katritzky AR Khashab NM Kirichenko N Singh A 《The Journal of organic chemistry》2006,71(24):9051-9056
In an operationally straightforward and efficient method, amidrazones and amidoximes are prepared in yields of 65-87% from imidoylbenzotriazoles by microwave heating for 5-20 min with the appropriate hydrazine or hydroxylamine. 相似文献
57.
A theoretical model of the EOF and hydrodynamic flow in wide closed cylindrical capillaries, after the application of a stepwise voltage, is developed. Analytical expressions have been obtained as a sum of the solutions for the direct flow and backflow in both periodical and aperiodical regimes with arbitrary pulse/pulse or pulse/pause durations and amplitudes. The numerical analysis, performed for a few types of periodical and aperiodical regimes, shows the qualitative peculiarities of the liquid velocity profiles and its displacement for different numbers of pulses. The obtained results are compared with those obtained in the case of open capillaries. The possibility of the application of aperiodical stepwise regime for the investigation of electrophoresis is discussed. 相似文献
58.
Volodymyr Samaryk Sergiy Varvarenko Ihor Tarnavchyk Nataliya Nosova Nataliia Puzko Stanislav Voronov 《Macromolecular Symposia》2008,267(1):113-117
A principal possibility of the utilization of polymer peroxides for the modification of polymer surfaces that provides an immobilization of the tailored quantity of peroxide groups at them has been established. The processes of polymer surface activation with following “grafting from” or “grafting to” utilizing immobilized peroxide groups has been studied using a FTIR-ATR spectroscopy, ellipsometry and measurements of contact angles. The proposed technique of polymer surface activation is based on the universal ability of carbon chain polymer to participate the free radical reactions. 相似文献
59.
Nina N. Chipanina Nataliya F. Lazareva Tamara N. Aksamentova Evgeniya P. Doronina Bagrat A. Shainyan 《Journal of Physical Organic Chemistry》2014,27(11):892-901
The intramolecular С=O→Si coordination in H‐complexes of (acetoxymethyl)trifluorosilane and (benzoyloxymethyl)trifluorosilane with proton donors HCl, PhOH, MeOH, and CHCl3 was investigated by density functional theory and second‐order Møller‐Plesset perturbation theory (MP2) methods. Interrelation and mutual influence of the intramolecular coordination bond С=O→Si and intermolecular hydrogen bonds C=O···H and Si–F···H in H‐complexes was established using the AIM and NBO analyses. The С=O→Si coordination is weakened by the C=O···H hydrogen bonding but enhanced by the Si–Fax···H hydrogen bonding. The structure of H‐complexes of (acetoxymethyl)trifluorosilane with proton donors in solution was determined by comparing the ν(C=O) and ν(Si–F) frequencies calculated using the conductor‐like polarizable continuum model and their experimental Fourier transform infrared values. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
60.
Jan C. Schmidt Alvydas Lisauskas Hartmut G. Roskos Nataliya V. Demarina 《Superlattices and Microstructures》2012
Field-pinning layers are an approach to improve the homogeneity of the electric field in a biased semiconductor structure of length above the Kroemer criterion. Building a THz Bloch oscillator with such a structure requires superlattice regions. Nevertheless, GaAs layers are investigated here. We compare different periodic structures (alternating transit and field-pinning layers) via simulating the field distribution. It is shown that the development of propagating Gunn domains is suppressed when field-pinning layers are included, but the homogeneity of the field is still not satisfying for the purpose of building a Bloch gain THz source. Depending on the temperature, intra- and inter-period inhomogeneities occur. 相似文献