Hardware/Software Support for Correlation Detection in Holographic Wavefront Sensors

Optics and Spectroscopy - An algorithm that automatically calculates aberrations in the holographic wavefront sensor scheme previously proposed by the authors is described, which enables measuring...     

On the Question of Spatial Transitions in a System of Atoms

Russian Physics Journal - This paper is a generalization of two of our preceding papers which considered, among other things, a version of the solution with a minimum and a maximum number of atoms...     

On the dimensionality of superconductivity in cuprate superconductors

The question of the dimensionality of superconductivity is considered within the framework of a model of superconductivity via asymmetric, delocalized “crystalline” π orbitals (analogous to the corresponding molecular orbitals) extending along chains of covalently bonded copper and oxygen ions. It is shown that superconductivity is preceded by a separation of the bonds in the CuO₂ layer into covalent and ionic bonds with ordering of the covalent bonds into chains. Such an ordering facilitates the formation of a crystalline π orbital lowering the crystal energy by the resonance energy of the π bond and is therefore favored. The superconducting current is created by non-dissipative motion of π-electron pairs along the asymmetric, “crystalline” π orbitals extending along chains of covalently bonded copper and oxygen ions, in the presence of an ionic bond between neighboring chains extending through the easily polarizable O²⁻ ions. This ionic bond correlates the motion of the electron pairs along all the π orbitals and stabilizes the superconducting state. Only in this sense is the apparent “onedimensionality” of superconductivity in cuprate superconductors to be understood. Zh. Tekh. Fiz. 68, 82–84 (November 1998)     

Coordination-cluster model for analyzing interactions in Na-O-H melts

A procedure for calculating the thermodynamic activity coefficients of oxygen and hydrogen in dilute Na-O-H system melts over the temperature range 300–600°C was suggested. The thermodynamic activity coefficients of hydrogen in liquid sodium calculated by the coordination-cluster model equations were used to determine the equilibrium hydrogen pressure over melts. The calculation results were compared with the experimental partial hydrogen pressures over the Na(excess)-Na₂O-NaH system at x _O = x _H. The calculated values were in qualitative agreement with the experimental data.     

On the weak isometries of the Boolean cube

The p-weak isometries of the Boolean cube are considered, i.e., the mappings of the cube onto itself which preserve a fixed distance p. Some necessary and sufficient conditions are obtained for coincidence of the group of p-weak isometries with the group of standard isometries (automorphisms of the cube).     

Entropy and Heat Capacity of a Degenerate Neutron Gas in a Magnetic Field

Russian Physics Journal - General expressions for the dependence of the entropy of a degenerate neutron gas in a magnetic field on the magnetic field magnitude and the neutron concentration with...     

Ablation of (111) and (001) Crystal Plates by Ultrashort Laser Pulses with Rotated Linear Polarization

JETP Letters - The dependence of the threshold fluence for surface ablation of such crystalline materials as silicon and diamond (with orientations (001) and (111)) on the direction of linear...     

Calculation of the Energy of Excited States with Zero Electron Orbital Angular Momenta

Russian Physics Journal - Within the framework of the variational method, as the result of a numerical calculation we have found the energy of the excited state and the screening constant of the...     

Energy and Screening Constants of a One-Dimensional Helium Atom in Excited States

Russian Physics Journal - In analogy with earlier calculations by the authors of screening constants and the energy of the ordinary threedimensional helium atom, this same program has now been used...