Flash-lamp annealing of boron implanted silicon

Structure and impurity behaviour of silicon doped by B⁺ ion implantation up to dose of 2 × 10¹⁵ ion/cm² have been investigated after lamp pulse annealing. It has been demonstrated that the implanted layer structure strongly depends on the implantation dose, light energy density, as well as the crystallographic orientation. The optimal annealing result in the structure, which is equivalent to that obtained in the thermal treatment, The impurity diffusive redistribution proved to be rather weaker then in the case of thermal treatment.     

Quadrupole deformation of electron shells in the lattice dynamics of compressed rare-gas crystals

The lattice dynamics of rare-gas crystals has been constructed taking into account the deformation of electron shells of the atoms of the dipole and quadrupole types, depending on the displacement of the nuclei. The obtained equations of lattice vibrations have been investigated in the long-wavelength approximation. The role played by the three-body interaction and the deformation of the electron shells in the violation of the Cauchy relation has been discussed. The calculated Birch elastic moduli for Xe and deviations from the Cauchy relation are in good agreement with the available experimental data over a wide range of pressures.     

Interaction and fusion of deformed nuclei

It is shown that the height of the barrier and its position, as well the depth of the capture well, are highly sensitive to the relative orientation of colliding strongly deformed nuclei. It is found that the fusion/capture cross sections and the nucleus-nucleus potential for heavy nuclear systems depend greatly on the magnitude and sign of the quadrupole deformation of nuclear surfaces. In order to describe correctly the cross section for the capture of heavy strongly deformed nuclei, it is necessary to perform averaging over all three angles that describe their relative orientation. Allowance for a hexadecapole deformation leads to a significant increase in the capture cross section for very heavy nucleus-nucleus systems.     

Search for a Neutrino with a Mass of 0.01–1.0 MeV in Beta Decays of <Superscript>144</Superscript>Ce–<Superscript>144</Superscript>Pr Nuclei

Spectra of electrons from beta decays of ¹⁴⁴Ce–¹⁴⁴Pr nuclei have been measured and analyzed in order to find a contribution from a heavy neutrino. For the neutrino with the mass m_νH in the interval of 150–350 keV, a new upper bound |U_eH|² ≤ (2?5) × 10^?3 at 90% C.L. has been found for the mixing parameter.     

Statistical irreversibility and instability of motion according to Lyapunov

The stability of the motion of a system of many particles according to Lyapunov is discussed. It is shown that the set of initial displacements of the particles decomposes into sets which result in stable, and consequently mixed, motions. The mixing rate is characterized by the average statistical Lyapunov index, for which an expression is obtained in terms of the interaction potential and a function modulating the initial displacements of the particles. An integral equation is obtained for the latter.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 4, pp. 83–87, April, 1981.     

Properties and construction of azo-dye reagents for inorganic photometric analysis

An approach to constructing new organic reagents (based on azo dyes) for photometric analysis is described. Its essence is the detailed consideration of the electronic structure of the chromophore nuclei of the dyes in the ground and excited states. Knowing the nature of the electron transition, it is possible to construct the organic reagents with optimal properties. The electronic structure of the azo dyes has been analysed in a pi-approximation by an MO LCAO SCF method.     

New Synthesis of 3-(2-Furyl)phthalides

3-(2-Furyl)phthalides were synthesized for the first time by the reaction of 2-formylbenzoic acids with furan derivatives in the presence of an acidic catalyst. It was found that the reaction of 2-formylbenzoic acids and 2-alkylfurans in aqueous dioxane in the presence of perchloric acid leads to a mixture of 2-carboxyaryldifurylmethanes and 3-furylphthalides, which can be separated easily by preparative column chromatography. __________ Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 9, pp. 1302–1304, September, 2005.