Synthesis and Structure of B-Carboranylphosphonates

Abstract

Photolysis of bis(m-carboran-9-yl)mercury and bis(p-carboran-2-yl)mercury in trimethylphosphite leads to the formation of dimethyl ethers of (m-carboran-9-yl)- and (p-carboran-2-yl)-phosphonic acids:     

On the Symmetrical Modes in a Cylindrical Nonisothermal Plasma Waveguide in a Finite External Magnetic Field

A MHD, symmetrical, nonpotential waves in nonuniform, cylindrical nonisothermal plasma waveguide placed in a finite external magnetic field H ₀ directed along the axis of the waveguide are considered. The thermal velocity of the electrons ν_Te = (kT_e/m_e)^1/2 (k — Boltzman's constant, T_e — temperature, m_e — mass of the electron) is not neglected. As a consequence we obtain one more solution in the plasma region and respectively an equation of third power on χ² — the transverse wave number. As far as we know only equations of second power on χ² describing non-potential waves are investigated. The dispersion equations are written solving the boundary-value problem. Our results coincide with well known ones when the electron thermal velocity tends to zero.     

Thermodynamic characterization of carbon black-filled rubbers

Unfilled and carbon black-filled samples of synthetic isoprene- and butadiene-methylstyrenebased rubbers were characterized by precise heat capacity measurements in the temperature interval 4.2–300 K. Both unfilled samples proved to behave in an essentially fracton-like way in the temperature interval 6–30 K. The excess thermodynamic quantities derived from the smoothed data suggested that the thermodynamic state of the elastomeric phase in the filled rubbers was intrinsically unstable.     

The decay of turbulence in the burgers model

Statistical characteristics of the turbulence in the Burgers model are obtained     

Synthesis and characterization of palladium nanoislands on the silicon surface

Samples representing a system of Pd nanoparticles on a Si surface is obtained. The metal is deposited onto the substrate by thermal evaporation in vacuum. The system of nanoparticles is formed using a thin screen located at an angle to the substrate and by vacuum annealing of ultrathin continuous palladium films. The chemical composition of the deposited substance is studied by Auger electron spectroscopy. The size and topology of the islands on the surface is established by scanning electron microscopy.     

Scattering of particles with internal degrees of freedom

The scattering of particles with a small number of internal degrees of freedom is considered. Billiard formalism is used to study the scattering of two such structurally complex particles. The main scattering characteristics are found. Various types of scattering modes are revealed. In particular, a mode is detected when the velocity of motion of such particles away from each other is higher than their approach velocity before the collision. The scattering of such particles is shown to occur after a finite number of collisions. A generalized Newton law is proposed for the collision of particles with a small number of degrees of freedom, and the form of the effective coefficient of restitution is found.     

Singularities motion equations in 2-dimensional ideal hydrodynamics of incompressible fluid

In this Letter, we have obtained motion equations for a wide class of one-dimensional singularities in 2D ideal hydrodynamics. The simplest of them, are well known as point vortices. More complicated singularities correspond to vorticity point dipoles. It has been proved that point multipoles of a higher order (quadrupoles and more) are not the exact solutions of two-dimensional ideal hydrodynamics. The motion equations for a system of interacting point vortices and point dipoles have been obtained. It is shown that these equations are Hamiltonian ones and have three motion integrals in involution. It means the complete integrability of two-particle system, which has a point vortex and a point dipole.