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1.
N. F. Pedchenko N. D. Trusevich V. F. Lavrushin 《Chemistry of Heterocyclic Compounds》1974,10(4):418-420
The shifts of the stretching vibrations of the hydroxyl groups of phenol and pentachlorophenol during the formation of intermolecular hydrogen bonds with 2-thienyl phenyl ketones containing substituents in the benzene ring were measured. A correlation dependence between theD
OH values and + substituent constants was established.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 4, pp. 482–485, April, 1974. 相似文献
2.
L. G. Mamsurova K. S. Pigalskiy N. G. Trusevich A. A. Vishnev M. A. Rogova S. Yu. Gavrilkin A. Yu. Tsvetkov 《JETP Letters》2015,102(10):662-667
The magnetization M(H) in the superconducting state, dc magnetic susceptibility χ(T) in the normal state, and specific heat C(T) near the superconducting transition temperature T c have been measured for a series of fine-crystalline YBa2Cu3O y samples having nearly optimum values of y = 6.93 ± 0.3 and T c = (91.5 ± 0.5) K. The samples differ only in the degree of nanoscale structural inhomogeneity. The characteristic parameters of superconductors (the London penetration depth and the Ginzburg–Landau parameter) and the thermodynamic critical field H c are determined by the analysis of the magnetization curves M(H). It is found that the increase in the degree of nanoscale structural inhomogeneity leads to an increase in the characteristic parameters of superconductors and a decrease in H c(T) and the jump of the specific heat ΔC/T c. It is shown that the changes in the physical characteristics are caused by the suppression of the density of states near the Fermi level. The pseudogap is estimated by analyzing χ(T). It is found that the nanoscale structural inhomogeneity significantly enhances and probably even creates the pseudogap regime in the optimally doped high-T c superconductors. 相似文献
3.
L.?G.?MamsurovaEmail author S.?Yu.?Gavrilkin K.?S.?Pigalskiy N.?G.?Trusevich A.?A.?Vishnev A.?Yu.?Tsvetkov 《Bulletin of the Russian Academy of Sciences: Physics》2015,79(6):770-773
Magnetization M(H,T) in magnetic fields H up to 90 kOe and at temperatures 2 K ≤ T < T c (where Tc is the superconducting transition temperature), along with magnetic susceptibility χ(T) in the normal state T c < T < 400 K for optimally oxygen-doped samples of YBa2Cu3O6.92 with varying degrees of defects in the crystal structure, are studied to determine the influence of structural inhomogeneity on the electron systems characteristics of cuprate superconductors. It is shown that the existence of structural inhomogeneity of samples leads to the manifestation of peculiarities appropriate to pseudogap regime in their properties. 相似文献
4.
L. G. Mamsurova K. S. Pigalskiy N. G. Trusevich N. B. Butko A. A. Vishnev 《Bulletin of the Russian Academy of Sciences: Physics》2010,74(8):1086-1089
We study the reasons for which the compound YBa2Cu3O
y
begins to lose its superconducting ability with a decrease in particle sizes to values of ∼0.1 μm. Our analysis of the results
of structural and magnetic studies has allowed us to reveal changes in the parameters of the crystal structure and of the
superconducting state in small particles of an HTSC and to show that the main cause of these changes is a special kind of
a structural disorder peculiar only to small particles of YBa2Cu3O
y
and is realized as a consequence of the need for nonequilibrium conditions during their synthesis. 相似文献
5.
L. G. Mamsurova N. G. Trusevich K. S. Pigalskiy A. A. Vishnev S. Kh. Gadzhimagomedov Zh. Kh. Murlieva D. K. Palchaev A. S. Bugaev 《Russian Journal of Physical Chemistry B, Focus on Physics》2018,12(5):908-915
A comparative study of the magnetization and static magnetic susceptibility of high-temperature superconductors (HTSC) YBa2Cu3Oy synthesized by two variants of the sol–gel method with different average sizes of crystallites 〈 D〉 ranging 0.4–2 μm has been performed in constant magnetic fields (Н ≤ 6 kOe). It has been shown that the different annealing temperatures and times, at which their crystal structure is formed, change both the average sizes of crystallites 〈D〉 and the sizes of the structural homogeneity regions 〈l〉 and, at the same time, the magnetic field penetration depth (λ) and the coherence length (ξ). As a result, such parameters as 〈D〉 ~ λ and 〈l〉 ~ ξ become comparable, leading to a change in the physical characteristics of HTSCs. It has also been shown that the superconducting transition temperature Tc determined from the measurements of magnetic characteristics in constant magnetic fields remains within values optimal for superconductivity (Tc ≈ 92 K) in the case of an optimal number (y) of oxygen atoms, which determine the levels of charge doping for a given compound. 相似文献
6.
A. M. Balagurov L. G. Mamsurova I. A. Bobrikov To Thanh Loan V. Yu. Pomjakushin K. S. Pigalskiy N. G. Trusevich A. A. Vishnev 《Journal of Experimental and Theoretical Physics》2012,114(6):1001-1011
The atomic structure of YBa2Cu3O y fine-crystalline HTSC samples with various average crystallite sizes ??D?? ranging from 0.4 to 2 ??m and an oxygen concentration y close to the optimal value for superconductivity (y ?? 6.93) is investigated by the neutron diffraction technique. We have found some effects associated with the redistribution of cations and oxygen atoms and with variations in the positions of atomic layers in the unit cell, which are not observed in macrocrystalline samples. In all probability, these effects appear due to nonequilibrium conditions of synthesis required for obtaining this compound in the fine-crystalline state. The results have made it possible to explain the peculiar physical properties of fine-crystalline YBa2Cu3O y samples (in particular, the coexistence of high superconducting transition temperatures T c and noticeably lower values of magnetization in strong magnetic fields for T < T c ). It is shown that a nanoscale structural inhomogeneity exists in fine-crystalline YBa2Cu3O y samples with the optimal oxygen content and changes the fundamental superconducting parameters, viz., the magnetic field penetration depth and the coherence length. 相似文献
7.
For regularly convergent functional series, an analog of the classical Borel relation between the maximum of the modulus of a sum and the maximal term of this series is obtained. 相似文献
8.
9.
L. G. Mamsurova A. A. Vishnev K. S. Pigalskiy N. G. Trusevich 《Bulletin of the Russian Academy of Sciences: Physics》2014,78(4):274-277
A comparative study of the structure-sensitive magnetic properties of fine-crystalline YBa2Cu3O y samples obtained by different methods (the sol-gel technique and mechanical activation) is performed. It is shown that a peculiar type of structural disordering extrinsical of macrocrystalline samples of the same compound, is a general property of fine-crystalline samples. This is due to the stabilization of the quasi-equilibrium state with incomplete atomic ordering when synthesizing this compound with a fine-crystalline microstructure. 相似文献
10.
E. N. Trusevich 《Moscow University Mathematics Bulletin》2014,69(5):193-197
The circuit complexity of monomial set computation is studied in the paper. In the model considered here, the complexity means the minimal number of composition operations sufficient for calculating the system from its variables. It is established that the considered complexity measure can be much less than known complexity measures corresponding to models admitting, for example, either multiplication operations only, or multiplication and division operations, or multiplication operations with the ability to use inverse variables. However, this feature of significant “computation strength” is not universal, which is confirmed by an appropriate example. Furthermore, for a system containing two monomials of two variables we obtained an exact complexity value. We have also established that duality reasons do not work (or work poorly) in calculations using composition operation. 相似文献