Effect of Mechanical Stress on the Splitting of Spin Sublevels in 4H-SiC

JETP Letters - The effect of static mechanical strain on the splitting of spin sublevels of color centers based on spin 3/2 silicon vacancies in silicon carbide at room temperature has been shown....     

Dynamics of a nonuniformly conducting gas flow in a magnetic field

The dynamics of a nonuniformly conducting gas flow in the channel of a MHD generator are investigated on the basis of numerical modeling. The initial shape of the plasmoids periodically entering the MHD channel qualitatively correspond to that noted in [6, 7]. The alkali metal seed is uniformly distributed over the entire flow. The mechanism of dynamic interaction of the plasmoids and the low-conductivity gas flowing over them, the variation of the shape of the plasmoids and the evolution of the gas dynamic structure of the flow are studied.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 5, pp. 135–145, September–October, 1989.     

“Electron ping-pong” on a one-dimensional lattice: Multiple reflections of the wave packet and capture of the wave function by an acceptor

Considering the problem of multiple reflections of a wave function from the ends of a lattice, we observe an interesting phenomenon: the wave function amplitude is concentrated on the impurity center after reflections. The solution obtained by expanding the total wave function a(t) on the impurity center in the partial amplitudes a_k(t), whose contributions become essential only after the kth reflection from the lattice end, seems to agree very well with the results of numerical modeling. We solve the problem of the capture of the wave function by an acceptor. The obtained results can be used to explain experimental data on charge transfer in artificial oligonucleotides and polypeptides. We find expressions for the electron capture probability in some limit cases, which can be considered estimates of the quantum output of the charge transport.     

Laser-Synchrotron Facility of the National Research Centre “Kurchatov Institute”

Crystallography Reports - The laser-synchrotron facility (LSF) of the National Research Centre “Kurchatov Institute” (NRC KI) is a unique research complex that combines unprecedented...     

New benzimidazole-2-yl-substituted polybenzimidazoles: Synthesis, properties, and hydrodynamic characteristics

The synthesis of novel benzimidazole-2-yl-substited polybenzimidazoles and initial compounds has been described. The polymers are studied by FTIR spectroscopy, TGA, and TMA. The hydrodynamic properties of macromolecules are investigated by translational diffusion and viscometry in 96% H₂SO₄; the molecular characteristics of the polymers are determined. Positive temperature dependences for intrinsic viscosities of the polymers are obtained. The polymers under study possess high hydrolytic stability with respect to sulfuric acid solutions up to 150°C and high thermal stability in the bulk. The TGA data correlate with the chemical structure of the polymers. The new polybenzimidazoles may be used as materials for the production of medium-temperature proton-conducting membranes.     

Quantitative Model of Large Magnetostrain Effect in Ferromagnetic Shape Memory Alloys

A quantitative model describing large magnetostrain effect observed in several ferromagnetic shape memory alloys such as Ni₂MnGa is briefly reported. The paper contains an exact thermodynamic consideration of the mechanical and magnetic properties of similar type materials. As a result, the basic mechanical state equation including magnetic field effect is directly derived from a general Maxwell relation. It is shown that the magnetic field induced deformation effect is directly connected with the strain dependence of magnetisation. A simple model of magnetisation and its dependence on the strain is considered and applied to explain the results of experimental study of large magnetostrain effects in Ni₂MnGa.     

High power all-fibered femtosecond master oscillator power amplifier at 1.56 μm

Direct amplification of output from chirped pulse oscillator (CPO) to 3.3?W of average power (pulse energy of 118?nJ in 20?ps pulse duration before compression) was achieved in a properly designed cladding pumped large mode area Er-doped fiber. Various configurations of CPO cavity with different FWHM of output spectrum and pulse duration were investigated. Fourier limit compression with 480?fs pulse duration and 32?kW peak power has been obtained for pulses with 14.8?nm FWHM spectrum. Subsequent nonlinear compression in a standard SMF-28 fiber yielded pulses as short as 145?fs.     

Energy conversion in the Carnot cycle during martensitic transformation

A Carnot cycle is proposed for a working material undergoing martensitic transformation while operating a finite temperature interval. The size of the interval depends on the thermodynamic characteristics of the transformation. Diagrams are presented to decribe the deformation of titanium under adiabatic and isothermal conditions. The diagrams confirm the possibility of realization of the transformation. A comparison is made with other known cycles. It is shown that transformation hysteresis diminishes the efficiency of the actual cycle.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 91–94, February, 1989.     

Structural-analytic theory of durability in multilevel formulation

Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 2, pp. 121–139, February, 1990.     

Influence of the Composition of Chloride-containing Solutions on the Corrosion of 12Cr18Ni10Ti Steel

The corrosion activity of chloride-containing solutions formed in production of ternary nitrogen-phosphorus-potassium fertilizers was studied. The inhibiting effect of hydroxide ions on the corrosion of 12Cr18Ni10Ti steel during the evaporation of solutions of nitrogen-phosphorus-potassium fertilizers was evaluated.