Lateral-surface superlattices in systems with spin-orbit coupling: Quantum states and bloch oscillations in an electric field

The quantum states of a two-dimensional electron gas with spin-orbit coupling located in the periodic potential of a lateral-surface superlattice are studied. The spin-split energy bands and the distribution of spin projections in the Brillouin zone are constructed. Bloch oscillations accompanied by spin precession in superlattices with spin-orbit coupling located in a constant electric field are studied.     

Nonconservative scheme with the isentropic condition in rarefaction waves as applied to the compressible Euler equations

A previously developed second-order accurate quasi-monotone scheme is tested using the Riemann problem with high initial pressure and density ratios. For shock waves, the scheme is conservative, while, in rarefaction waves, the isentropic condition along the trajectory of a Lagrangian particle is used instead of conservativeness in energy. It is shown that the shock front position produced by the scheme has no considerable errors typical of a representative set of conservative quasi-monotone schemes of various orders of accuracy. The numerical accuracy is significantly improved in the case of moving grids with a contact discontinuity explicitly introduced in the form of a grid node. It is shown how the method can be extended to cover the multidimensional case and the presence of additional terms in the original equations.     

Symmetric difference schemes of componentwise splitting and equivalent predictor-corrector scheme based on the Godunov method as applied to multidimensional gasdynamic simulation

An approach is described for improving the accuracy of numerical solutions to multidimensional gasdynamic problems produced by Godunov’s schemes. The basic idea behind the approach is to construct symmetric difference schemes based on splitting with respect to spatial variables with the subsequent transformation into equivalent predictor-corrector schemes. It is shown that the computation of “large” values by solving the one-dimensional Riemann problem at the interface of two neighboring cells leads to approximation errors in Godunov’s schemes. It is proposed to reconstruct large values so as to eliminate this source of errors. The time integration step in the modified schemes is consistent with that in the one-dimensional schemes and, on spatially uniform meshes, is 2 and 3 times larger than that in Godunov’s classical schemes for two- and three-dimensional problems, respectively. The numerical results obtained for test problems confirm the improvement of the accuracy of solutions produced by the modified schemes.     

Synthesis of new enantiomerically pure β-amino alcohols of the pinane series

A series of new β-amino alcohols with pinane structure, (+)- and (?)-3α-amino-10β-pinan-4β-ols, 4β-amino-10β-pinan-3α-ol, and 4α-amino-10β-pinan-3α-ol have been synthesized with the goal of using them as organocatalysts in the aldol reaction of isatin with acetone.     

Oxidation of terpenoid diols with chlorine dioxide. Easy preparation of α-hydroxyketones

Oxidative dehydrogenation of vicinal diols of bornane and pinane type with chlorine dioxide in dimethylformamide has yielded α-hydroxyketones with high selectivity. 3α-Hydroxy-10β-pinane-4-one has been prepared for the first time with yield of 63–65%; the product structure has been confirmed by X-ray diffraction studies.     

On the Fedorov Prize Competition held by the Russian Academy of Sciences

Crystallography Reports -     

Determination of energy deposition into the cells of nuclear-pumped lasers

A review of experimental and analytical investigations of the energy deposition into the cells of nuclear-pumped lasers is presented. Three experimental techniques for energy deposit determination are considered: pressure jump method, interferometric method, and the method of string calorimeters. Comparative analysis of experimental and analytical data on the energy deposit is conducted.     

Influence of the Optical Activity on Self-Bending of a Light Beam in Cubic Photorefractive Crystals in an External Alternating-Sign Electric Field

Results of theoretical analysis and numerical calculations of the influence of natural optical activity and linear birefringence, induced by an external alternating-sign electric field, on the self-action of light beams with one-dimensional input intensity distribution propagating in sillenite crystals are presented.