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21.
Balandina A Kalinin A Mamedov V Figadère B Latypov S 《Magnetic resonance in chemistry : MRC》2005,43(10):816-828
(1)H, (13)C and (15)N NMR chemical shifts for a variety of novel quinoxalines were determined by different 2D methods and were calculated using the GIAO DFT approach. Comparison with experimental data shows good correlations in the case of (1)H, (13)C and (15)N chemical shifts. Different combinations of basis sets were tested. In non-polar solvents quinoxalines exist as dimers owing to strong hydrogen bonding. Calculations for dimers improve the correlation between experiment and theory. Additive empirical methods for estimating chemical shifts have drawbacks and have to be used with a great care for this type of compound. 相似文献
22.
23.
N. A. Nesmeyanov K. P. Butin A. V. Kalinin O. A. Reutov 《Russian Chemical Bulletin》1973,22(8):1867-1868
Conclusions The polarographic data and the data of the IR spectra of the-mercurated esters of the cinnamic and crotonic acids show that in these compounds the- conjugation of the C-Hg bond with the C=O group is weakly expressed, and may be completely absent.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1912–1913, August, 1973. 相似文献
24.
E. A. Petrushkina D. V. Khomishin N. E. Mysova A. V. Orlinkov V. N. Kalinin A. B. Ponomarev I. A. Godovikov Ya. V. Zubavichus A. A. Veligzhanin 《Moscow University Chemistry Bulletin》2007,62(5):276-280
2-Butyl-4,9-decadienoic and 2-butyl-4,9-dimethyl-4,9-decadienoic acids, structural isomers of 2-cyclohexylgeranylacetic acid, which is an active component of the wound healing ointment cygerol, have been synthesized. Hydrocarbon chains C10 have been obtained by the one-pot method of formation of long-chain hydrocarbons, namely, by the telomerization reaction of 1,3-dienes with nucleophiles catalyzed by palladium complexes. A heterogeneous palladium-zeolite catalyst has been used for the first time in telomerization of isoprene with piperidine. 相似文献
25.
B. A. Demidov V. P. Efremov Yu. G. Kalinin V. A. Petrov S. I. Tkachenko K. V. Chukbar 《Technical Physics》2012,57(3):405-409
The time ranges of the fracture of polymethylmethacrylate and polystyrene during the action of a shock wave generated by a
high-current pulsed electron beam are experimentally determined using laser probing in combination with electron-optical chronography.
It is shown that fractures occur during unloading of a material, i.e., after the passage of the shock wave. Although the characters
of fracture of these polymers near the surface irradiated by electron beam are different, the fracture wave velocities in
them are found to be close. 相似文献
26.
J. V. Kasiuk J. A. Fedotova M. Marszalek A. Karczmarska M. Mitura-Nowak Yu. E. Kalinin A. V. Sitnikov 《Physics of the Solid State》2012,54(1):178-184
The elemental and phase compositions and the magnetic state of metal particles in FeCoZr-Pb(ZrTi)O3 granular nanocomposites (GNCs) synthesized by ion-beam sputtering of composite targets in oxygen-containing media at different
oxygen partial pressures have been studied. The phase transformations in GNCs have been monitored by the Raman and M?ssbauer
spectroscopy techniques. Correlation between the oxygen pressure during GNC synthesis and the valence state of iron ions in
metal granules has been established. It has been confirmed that (i) the degree of metal oxidation increases with increasing
oxygen pressure and (ii) the degree of crystallinity of oxides increases as a result of annealing. It has been established
that the percolation threshold in GNCs can also be varied by changing the oxygen pressure during GNC synthesis. 相似文献
27.
Kalinin A. A. Sharipova S. M. Islamova L. N. Fazleeva G. M. Busyurova D. N. Sharipova A. V. Fominykh O. D. Balakina M. Yu. 《Russian Chemical Bulletin》2022,71(5):1009-1018
Russian Chemical Bulletin - Two new D—π—A chromophores with the tricyanofuranyl acceptor (A), an amphi-divinyl quinoxaline π-electron conjugated bridge, and the carbazole or... 相似文献
28.
We propose a novel class of nonvolatile memory elements based on the modification of the transport properties of a conducting carbon nanotube by the presence of an encapsulated molecule. The guest molecule has two stable orientational positions relative to the nanotube that correspond to conducting and nonconducting states. The mechanism, governed by a local gating effect of the molecule on the electronic properties of the nanotube host, is studied using density functional theory. The mechanisms of reversible reading and writing of information are illustrated with a F4TCNQ molecule encapsulated inside a metallic carbon nanotube. Our results suggest that this new type of nonvolatile memory element is robust, fatigue-free, and can operate at room temperature. 相似文献
29.
V. A. Belousov A. B. Granovsky Yu. E. Kalinin A. V. Sitnikov 《Physics of the Solid State》2007,49(10):1848-1855
The concentration and temperature dependences of the thermopower of composites containing Co nanoparticles embedded in the Al2O n dielectric matrix are investigated. Below the percolation threshold, i.e., in the tunneling conduction region, the absolute values of the thermopower of the composites under investigation are less than those above the percolation threshold. It is revealed that, in the tunneling conduction region, the slope of the temperature dependences of the thermopower changes at a temperature of ~205 K. This can indicate that the thermopower is sensitive to a change in the mechanism of conduction from the Mott law ln(σ) ∝ (1/T)1/4 to a power relation that corresponds to the model of inelastic resonant tunneling through a chain of localized states in the dielectric matrix. The introduction of oxygen in the course of sputtering brings about a decrease in the absolute values of the thermopower; however, the character of variation in the concentration and temperature dependences of the thermopower remains unchanged. 相似文献
30.
E. T. Apasov A. V. Kalinin S. L. Ioffe V. A. Tartakovsky 《Russian Chemical Bulletin》1993,42(9):1604-1605
Trimethylsilyloxy derivatives of 1,2,4-triazole, 3(5)-nitro-1,2,4-triazole, and tetrazole are inert toward 2-nitro-1-trimethylsilyloxy-2-azapropane, but they react with 1-chloro-2-nitro-2-azapropane to give the corresponding nitraminomethyl derivatives. Silyiated 1,2,4-triazole undergoes bis-nitraminomethylation to give a triazolium salt.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 9, pp. 1666–1668, September, 1993. 相似文献