Spin-phonon-electron correlations in high-temperature superconductors
Spin-phonon-electron correlations in high-temperature superconductors
А.V. Vedyaev, М.I. Zubtsov, М.А. Savchenko, and А.V. Stefanovich
Spin excitation (spin fluctuation) spectra in the superconducting phases of hightemperature $La_{2-x}Sr_xCuO_4$ - and $YBa_2Cu_3O_{7-y}$-type superconductors are considered, as well as tl1eir influence 011 tl1e therшodynamic characteristics of these compounds, primarily on tl1eir low-temperature heat capacity, which is shown to have а power dependeпce on temperature. In the region of values of the $k\simeq k_F$ (Тikp is the Fermi momentum) wave vector, the spectra of coupled spinphonoп vibratioпs responsiЫe for the appearance of coupled electron pairs in the superconducting state are analyzed. It is shown that the critical temperature $Т_с$ of high-temperature superconductors, determined Ьу the. spin-phonon coupling parameter $\tilde{\zeta}$, is limited for tl1e compounds studied, which motivates а more detailed coпsideration of spin-electron correlations in high-temperature superconductors.
Show AbstractThe effect of electric field on hysteresis phenomena in $Rb_2ZnCl_4$ crystals grown from the solution and from the melt
The effect of electric field on hysteresis phenomena in $Rb_2ZnCl_4$ crystals grown from the solution and from the melt
В.А. Strukov, Е.Р. Ragula, and S.N. Gorshkov
Hysteresis phenomena on the curve of permittivity versus applied electric field and temperature in the region of the Сuriе temperature have been studied for $Rb_2ZnCl_4$ crystals grown from the solution and from the melt. The results indicate that hysteresis phenomena depend on the defect concentration of the specimen crystal structure.
Show AbstractComputation of dielectric waveguides with intricate cross-sections Ьу the variate-difference method
Computation of dielectric waveguides with intricate cross-sections Ьу the variate-difference method
А.N. Bogolyubov and Т.V. Edakina
А computation algorithm is suggested for dielectric waveguides with intricately shaped cross-sections based on the variate-difference method.
Show AbstractА class of spherically symmetric Finslerian metric functions with indicatrix of constant curvature
А class of spherically symmetric Finslerian metric functions with indicatrix of constant curvature
G.А. Asanov
А broad class of exact solutions is indicated for Finslerian equations in the static spherically symmetric case under the assumption· that the fibers are spaces of constant curvature.
Show AbstractThe influence of bulk and surface recombination effects on the time lag in microwave opt ic control
The influence of bulk and surface recombination effects on the time lag in microwave opt ic control
L.А. Borisov, Wang Shan, V.V. Gladun, Yu.А. Pirogov, D.А. Tishchenko, and Е.I. Fominova
It is shown that as the thickness of а longitudinal semiconductor insert in а rectangular waveguide decreases, the effective lifetime of free carriers photoexcited bу light diminishes owing to the predominance of the surface recombination over the bulk one in thin plates. Ву contrast, in thick samples, the more protracted bulk recombination processes prevail. They provide а higher factor of microwave energy modulation but the time lag of the response is larger.
Show AbstractExperimental study of а Cerenkov-type sectioned relativistic microwave-frequency multiplier
Experimental study of а Cerenkov-type sectioned relativistic microwave-frequency multiplier
А.F. Aleksandrov, S.Yu. Galuzo, V.I. Kanavets, and А.М. Kuznetsov
An experimental study of а Cerenkov-type two-section frequency multiplier with а multiplicity factor n = З has been performed. А Cerenkov generator of the type of backward-wave tube 11as beell used as the first multiplier section and а traveling-wave tube has served as its second section. The feasibility of creating such devices in the relativistic region of electron energy using heavy-current electron beams has been demonstrated.
Show AbstractProducts of soil corrosion of an iron sample as studied Ьу Mossbauer spectroscopy
Products of soil corrosion of an iron sample as studied Ьу Mossbauer spectroscopy
А.A. Novakova,Т.S. Gendler, N.D. Manyurova, and R.А. Тurishcheva
The chemical and phase compositions of the outer corrosion layer has been studied in an archeological iron nail that lay buried in the soil of the Smolensk region since 12th century. Combined experimental methods revealed that this layer comprised finely dispersed $alpha Fe_2O_3 gamma Fе_2O_3$, and partially oxidized $FeS_2, FeCl_2\cdot2H_2O, Fe_3(PO_4)_2\cdot 8H_2O, FeSO_3\cdot 3H_2O and FeSO_4\cdot4H_2O$.
Show AbstractPhase diagram of а quasi-binary system $Er_{1-x}Tb_xMn_2$ synthesized at а high pressure
Phase diagram of а quasi-binary system $Er_{1-x}Tb_xMn_2$ synthesized at а high pressure
А.S. Ilyushin, I.А. Nikanorova, М. Al-Dervish, А.V. Tsvyashchenko, L.N. Fomicheva, and Shi Lei
The phase composition and atomic-crystalline structure of alloys of the quasibinary system $Er_{1-x}Tb_xMn_2$, synthesized at high pressures, have been studied bу X-ray analysis. The phase diagram of this system in the composition-pressure coordinates is constructed.
Show AbstractInterval estimation of measurement model parameters in remote sounding problems
Interval estimation of measurement model parameters in remote sounding problems
Yu.P. Pyt'ev, V.A. Gazaryan, G.V. Sukhorukova, T.V. Matveeva
An interval estimation method is suggested as an effective principle for estimating the atmospheric parameters from measurements of solar radiation intensity. The size of the confidence set is regarded as a quantitative measure of information output of a particular experiment with respect to the parameters of the object under study. As an illustration, estimates of the total ozone and aerosol contents, the optical aerosol parameter, and of the vertical ozone distribution are presented.
Show AbstractThe motive force of the Carnot engine operating at maximum power production
The motive force of the Carnot engine operating at maximum power production
B.B. Shishkin
An existence theorem is proved for the motive force in the Carnot engine producing maximum power. The virial theorem is refined. The motive forces of the engine are expressed in terms of kinematic characteristics of the engine piston. It is shown that the process of isothermal expansion of the ideal gas obeys the "3/2" law establishing the dependence of the piston coordinate on time.
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