Optical properties of one-dimensional subwave plasmonic nanostructures

Nanogratings formed by parallel gold nanowires on a quartz substrate have been fabricated. Their transmission and reflection spectra have been studied experimentally. Numerical simulation of the transmission (reflection) spectra has been performed. The simulated spectra agree well with the experimental ones. A package has been proposed, which combines the experimental techniques of the structure fabrication and theoretical methods for calculating the parameters of optical spectra. This package is a promising tool for designing and fabricating optoelectronic devices such as filters, polarizers, and switches.     

Comparative analysis of long-range effect using RBS technique and microhardness measurements

The concentration of point defects in silicon samples bombarded by Ar ions with an energy of 30 keV with a dose of 10¹⁶ cm⁻² is investigated using Rutherford backscattering combined with ion channeling. It is revealed that there is a variation of point defect concentration on the side of a sample opposite to the bombarded one. At the same time, an increase in the microhardness is observed there. These results are evidence in favor of the long-range effect under ion bombardment.     

Pyrometer unit for GaAs substrate temperature control in an MBE system

An optical pyrometer designed for precision measurement of the GaAs substrate temperature during MBE growth is considered. The pyrometer can be calibrated against a certain characteristic absolute temperature that is visually determined from a change in the RHEED pattern. This enables one to calculate the absolute temperature of the substrate with regard to its radiant emissivity and minimize the inaccuracy of radiation temperature measurement. The inaccuracy is associated with the deposition of growth products on the pyrometer window.     

Numerical simulation of axisymmetric turbulent jets

The flow in axisymmetric turbulent jets is numerically simulated with the use of a semi-empirical second-order turbulence model including differential transport equations for the normal Reynolds stresses. Calculated results are demonstrated to agree with experimental data. __________ Translated from Prikladnaya Mekhanika i Tekhnicheskaya Fizika, Vol. 49, No. 5, pp. 55–60, September–October, 2008.     

Rigorous three-dimensional theory of the parametric excitation of space-charge waves in semiconductors

We analyze the stability against parametric excitation of space-charge waves of the space-charge field induced in a semiconducting crystal by a traveling light grating. We show that when the grating velocity is low, an important element of the analysis is the allowance for higher Fourier harmonics of the field. By combining analytic and numerical methods we study the stability against an increase in the amplitude of small three-dimensional perturbations of a general type. We find that instability is possible only within a single range of light-pattern velocities and that it leads to selective excitation of one-dimensional perturbations. Finally, we use the results of our analysis to interpret experiments on the generation of spatial subharmonics in sillenite crystals. Zh. éksp. Teor. Fiz. 114, 1034–1046 (September 1998)     

Quantum-chemical investigation of the electronic structure of chlorocyclopropanes and hydrogenolysis of C-Cl bonds in gem-dichlorocyclopropanes

Conclusions The electronic structure of cyclopropane, chloro- and gem-dichlorocyclopropane, and a number of their derivatives has been investigated by the CNDO/2 method. A nucleophilic mechanism for the hydrogenolysis of the C-Cl bonds in chlorocyclopropanes has been proposed on the basis of the results. The influence of the substituents in the cyclopropane ring on the course of the reaction has been investigated, and correlations between the charges on the atoms and the Hammett constants for the substituents have been obtained and discussed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 1962–1965, September, 1982.We thank A. A. Bagatur'yants and A. I. D'yachenko for their useful discussions.