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101.
Valentine P. Ananikov Prof. Konstantin A. Gayduk Nikolay V. Orlov Dr. Irina P. Beletskaya Prof. Victor N. Khrustalev Dr. Mikhail Yu. Antipin Prof. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(7):2063-2071
The present study reports the evidence for the multiple carbon–carbon bond insertion into the metal–heteroatom bond via a five‐coordinate metal complex. Detailed analysis of the model catalytic reaction of the carbon–sulfur (C? S) bond formation unveiled the mechanism of metal‐mediated alkyne insertion: a new pathway of C? S bond formation without preliminary ligand dissociation was revealed based on experimental and theoretical investigations. According to this pathway alkyne insertion into the metal–sulfur bond led to the formation of intermediate metal complex capable of direct C? S reductive elimination. In contrast, an intermediate metal complex formed through alkyne insertion through the traditional pathway involving preliminary ligand dissociation suffered from “improper” geometry configuration, which may block the whole catalytic cycle. A new catalytic system was developed to solve the problem of stereoselective S? S bond addition to internal alkynes and a cost‐efficient Ni‐catalyzed synthetic procedure is reported to furnish formation of target vinyl sulfides with high yields (up to 99 %) and excellent Z/E selectivity (>99:1). 相似文献
102.
L. D. Blokhintsev V. O. Eremenko B. F. Irgaziev Yu. V. Orlov 《Bulletin of the Russian Academy of Sciences: Physics》2011,75(4):505-510
3H and 3He nuclei are considered in a two-body model (3H = n + d; 3He = p + d). Two independent approaches are used: in the first, interaction is described by the folding potential, while NN potentials are taken in the Hulthen form with allowance for violations of isotopic invariance. The second approach features
phenomenological Hulthen and Yukawa Nd potentials used as Nd interaction. In both approaches, the binding energies, vertex constants, and asymptotic normalization coefficients in the
N+d channel are calculated. 相似文献
103.
S. G. Ovchinnikov Yu. S. Orlov I. A. Nekrasov Z. V. Pchelkina 《Journal of Experimental and Theoretical Physics》2011,112(1):140-151
The electronic structure of LaCoO3 at finite temperatures is calculated using the LDA+GTB method taking into account strong electron correlations and possible
spin crossover upon an increase in temperature. Gap states revealed in the energy spectrum of LaCoO3 reduce the dielectric gap width upon heating; this allowed us to describe the insulator-metal transition observed in this
compound at T = 500–600 K. The temperature dependence of the magnetic susceptibility with a peak at T ≈ 100 K is explained by the Curie contribution from thermally excited energy levels of the Co3+ ion. At high temperatures, the Pauli contribution from a band electron is added and the total magnetization of LaCoO3 is considered as the sum M
tot = M
loc + M
band. The second term describes the band contribution appearing as a result of the insulator-metal transition and facilitating
the emergence of a high-temperature anomaly in the magnetic susceptibility of LaCoO3. 相似文献
104.
L. K. Orlov E. A. Shteinman N. L. Ivina V. I. Vdovin 《Physics of the Solid State》2011,53(9):1798-1805
The light-emitting properties of cubic silicon carbide films grown by vacuum vapor phase epitaxy on Si(100) and Si(111) substrates
under conditions of decreased growth temperatures (T
gr ∼ 900–700°C) have been discussed. Structural investigations have revealed a nanocrystalline structure and, simultaneously,
a homogeneity of the phase composition of the grown 3C-SiC films. Photoluminescence spectra of these structures under excitation of the electronic subsystem by a helium-cadmium
laser (λexcit = 325 nm) are characterized by a rather intense luminescence band with the maximum shifted toward the ultraviolet (∼3 eV)
region of the spectral range. It has been found that the integral curve of photoluminescence at low temperatures of measurements
is split into a set of Lorentzian components. The correlation between these components and the specific features of the crystal
structure of the grown silicon carbide layers has been analyzed. 相似文献
105.
106.
Flocculation of synthetic latexes with a quaternary ammonium base derived from resin acids and rosin
N. V. Kryuchkova Yu. N. Orlov D. A. Golovacheva S. V. Levanova 《Russian Journal of Applied Chemistry》2011,84(2):284-288
The flocculating effect of a quaternary ammonium compound based on resin acids and rosin in the course of rubber recovery from SKMS-30 ARK butadiene-α-methylstyrene latex was studied. The agent shows promise for commercial use. 相似文献
107.
108.
D. A. Davydov A. A. Rakhnyanskaya V. N. Orlov A. V. Bychkova A. L. Kovarskii A. A. Yaroslavov 《Polymer Science Series A》2010,52(7):693-703
Adsorption of the synthetic polycation poly-N-ethyl-4-vinylpyridinium bromide (PEP) on the surface of bilayered lipid vesicles (liposomes) is studied. Two types of liposomes
are used: (i) traditional two-component liposomes formed from neutral phosphatidylcholine (PC) and anionic diphosphatidylglycerol
(cardiolipin, CL2−) and (ii) PC/CL2− anionic liposomes with the built-in nonionogenic surfactant poly(ethyleneglycol) cetyl ether with a degree of polymerization
of 20 (Brij-58). PEP is quantitatively linked with both types of liposomes; this process is electrostatic in character and
fully reversible. The formation of a poly(ethylene glycol) layer on liposomal membrane decreases the stability of polycation-liposome
complexes in aqueous salt solutions. Adsorption of PEP on the surface of PC/CL2− liposomes is accompanied by their aggregation; PC/CL2−/Brij liposomes do not aggregates, even during complete neutralization of their charge by the adsorbed PEP. DSC measurements
showed that the adsorption of the polycation is accompanied by microphase separation in the liposomal membrane: formation
of domains, which are composed primarily of CL2− molecules and linked to the complex with PEP, and regions, where electroneutral lipids are primarily concentrated. With the
use of a spin probe, the packing density of bilayers (their microviscosity) is estimated, and a preferential localization
of the probe at the boundaries of lipid domains in the membrane based on PC/CL2−/Brij liposomes is proposed. The causes of the aggregative stability of three-component PC/CL2−/Brij liposomes are described, and the structure of the prepared polymer-liposome complexes is discussed. 相似文献
109.
110.
Muyakshin S. I. Odnosevtsev V. A. Orlov I. Ya. 《Radiophysics and Quantum Electronics》2000,43(12):989-998
We present the results of theoretical and experimental studies of the field structure of a distributed flexural-wave antenna. The efficiency of mechanical-acoustical transformation in such an antenna and the prospects for its applications in ultrasound systems of nondestructive testing are estimated. 相似文献