Crystal Structure of Decakis(μ-chloro)-tetrakis(1,2,4-triphenylcyclopentadienyl)-hexakis(tetrahydrofuran)-di-potassium-tetra-neodymium(III) Tetrahydrofuran Trisolvate

Journal of Chemical Crystallography - The crystal structure of decakis(μ-chloro)-tetrakis(1,2,4-triphenylcyclopentadienyl)-hexakis(tetrahydrofuran)-di-potassium-tetra-neodymium(III)...     

Estimates of the Best Approximation of Polynomials by Simple Partial Fractions

An asymptotics of the error of interpolation of real constants at Chebyshev nodes is obtained. Some well-known estimates of the best approximation by simple partial fractions (logarithmic derivatives of algebraic polynomials) of real constants in the closed interval [?1, 1] and complex constants in the unit disk are refined. As a consequence, new estimates of the best approximation of real polynomials on closed intervals of the real axis and of complex polynomials on arbitrary compact sets are obtained.

     

Electron Energy-Loss Spectroscopy Study of the Change in the Free-Electron Density in Thin Superconducting NbN Films under Ion-Beam Irradiation

The change in the free-electron density in ultrathin (5 nm) superconducting NbN films in the initial state and after irradiation by O⁺ ions to doses of (0.1–0.9) × 10¹⁷ cm^–2 has been studied by electron energy-loss spectroscopy (EELS). The analysis has been performed on cross section samples prepared by the focused ion beam method, using plasmon oscillations with energies up to 50 eV. The radiation-induced replacement of nitrogen atoms with oxygen atoms in niobium nitride is found to change the electrical properties of the material, which leads to a decrease in the free-electron density with an increase in the irradiation dose.     

Syntheses of chiral fused 4,5-diazafluorene–bis(nopinane) derivatives

1. Download : Download high-res image (122KB)
2. Download : Download full-size image

     

On the Number of 5‐Cycles in a Tournament

We find a formula for the number of directed 5‐cycles in a tournament in terms of its edge scores and use the formula to find upper and lower bounds on the number of 5‐cycles in any n‐tournament. In particular, we show that the maximum number of 5‐cycles is asymptotically equal to , the expected number 5‐cycles in a random tournament (), with equality (up to order of magnitude) for almost all tournaments.     

Effect of nonequilibrium processes in the infrasonic and ultrasonic regions of a nozzle on population inversion in flow of CO2 - N - O2 - H2O gas mixtures

The processes of oscillatory relaxation in flow through nozzles of CO₂, N₂, O₂, H₂O gas mixtures are studied. The effect of various oscillatory-oscillatory and osciallatory-translational exchange channels between mixture components and CO₂ intermode energy-exchange Channels on population inversion is examined. The importance of considering nonequilibrium processes in the infrasonic region of the nozzle is noted. The effect of inclined shock waves on flow characteristics in the supersonic nozzle region and population inversion is studied.     

Hamiltonian Formalism for the Problem of Optimal Motion Control under Multiple Criteria

Doklady Mathematics - This paper describes methods for optimizing solutions to problems of controlled dynamics under multiple criteria. Such problems are usually solved by reduction to scalarized...     

Research of Nanostructured Carbon Felt Materials as Electrodes of Vanadium Flow Batteries

Russian Journal of Electrochemistry - Flowing vanadium batteries are gaining great popularity in the world and are already ahead of lead-acid batteries in terms of installed capacity, but are far...