Plane Wave Solutions to the Equations of Electrodynamics in an Anisotropic Medium

Siberian Mathematical Journal - Under examination is the system of equations of electrodynamics for a nonconducting nonmagnetic medium with the simplest anisotropy of permittivity. We assume that...     

One class of nonscattering acoustic shells for a model of anisotropic acoustics

We consider a model of linear acoustics describing diffraction of an acoustic wave on a local anisotropic inhomogeneity. Under study is the existence of inhomogeneities which do not scatter the incident acoustic fields that are generated by any exterior compactly supported sources. We prove the existence of the above-mentioned inhomogeneities. Some constructive way is given of constructing a class of anisotropic media depending on an arbitrary function of one variable. We obtain some explicit formulas that define the main parameters of the shell.     

Thermal and acoustic effects in absorbing liquids under the action of pulsed light beams

We present the results from simulating the impact of pulsed light beams of different spatial structures (Gaussian, Bessel, singular) in absorbing liquids. Profiles of refractive index inhomogeneities excited in a medium are calculated and the kinetics of their relaxation is studied.     

Reaction of N′-(Arylmethylidene)-2-oxo-2H-chromene-3-carbohydrazides with Methyl 1-Bromocycloalkanecarboxylates and Zinc

Russian Journal of General Chemistry - Depending on the ring size in the Reformatsky reagent and the nature of substituents in arylmethylidene fragment, the reactions of Reformatsky reagents...     

Features of an InAsSbP epilayer formation on an InAs support by metalorganic vapor phase epitaxy

Epitaxial layers in a system of InAs_1–x–ySb_yP_x solid solutions in the composition range of 0 < x < 0.72 were obtained on an InAs(001) substrate by metalorganic vapor phase epitaxy (MOVPE). The layer-by-layer analysis of obtained structures by secondary ion mass spectrometry showed a gradient change in the composition along the growth direction. A dramatic change in the composition at the layer/substrate heteroboundary was observed for the quaternary InAsSbP solid solutions due to the presence of radicals of arsenic compounds in the gas phase. Upon MOVPE deposition on the InAs substrate in a system of InAsSbP solid solutions, the decrease in the solid-phase content of arsenium by less than (1–x–y) < 0.3 resulted in a suppression of the deposited layer gradientness, as well as suppressed fluctuations in the composition in the initial transition layer.     

IR luminescence of bismuth-containing centers in materials prepared by impregnation and thermal treatment of porous glasses

The properties of bismuth-containing luminescent materials prepared by impregnating a porous glass with an aqueous solution of bismuth and aluminum salts followed by thermal treatment are studied. The formation of a variety of bismuth-containing centers luminescent in the near infrared range of the spectrum is revealed, one of which is the Bi⁺ monocation. At high temperatures, along with it, bismuth-containing cluster-type luminescent centers are apparently formed.     

Low-temperature plasticity in nanocrystalline titanium and copper

The stress-strain compressive curves, temperature dependences of the yield stress, and small-inelastic-strain rate spectra of coarse-grained and ultrafine-grained (produced by equal-channel angular pressing) titanium and copper are compared in the temperature range 4.2–300 K. As the temperature decreases, copper undergoes mainly strain hardening and titanium undergoes thermal hardening. The temperature dependences of the yield stress of titanium and copper have specific features which correlate with the behavior of their small-inelastic-strain rate spectra. Under the same loading conditions, the rate of microplastic deformation of ultrafine-grained titanium is lower than that of coarse-grained titanium and the rate peaks shift toward high temperatures. The deformation activation volumes of titanium samples differing in terms of their grain size are (10–35)b ³, where b is the Burgers vector magnitude. The dependences of the yield stress on the grain size at various temperatures are satisfactorily described by the Hall-Petch relation.     

Alkaloids of the flora of Siberia and Altai: XX. Synthesis of 5-aryl(hetaryl)-substituted anthranilic acid esters

Cross-coupling of methyl 2-acetylamino-5-bromobenzoate and 5′-bromolappaconitine with aryl-, furyl-, pyridyl-, and 5-acetylthiophen-2-ylboronic acids or 1-(2-fluoroquinolin-3-yl)-4,4,5,5-tetramethyl-1,3,2-dioxaborolane gave the corresponding 5-aryl(hetaryl)-substituted anthranilic acid derivatives. The use of the two-phase toluene-water system as reaction medium and addition of tetrabutylammonium bromide allows the cross-coupling to be accomplished under mild conditions. The catalytic system Pd(dba)₂-AsPh₃ was found to be efficient in the cross-coupling of methyl 2-acetylamino-5-bromobenzoate with furyl- and pyridylboronic acids, whereas the system Pd(OAc)₂-(o-Tol)₃P ensured good results in the reactions of 5′-bromolappaconitine with hetarylboronic acids. Facile esterification at the C⁸-OH and C⁹-OH groups of the aconitane skeleton was observed in the reactions of 5′-bromolappaconitine and 5′-phenyllappaconitine with phenylboronic acid. 5′-Bromo-8,9-O-(phenylboranediyl)lappaconitine under the Suzuki reaction conditions underwent hydrolysis of the boronic ester moiety with formation of the cross-coupling product of 5′-bromolappaconitine with phenylboronic acid.     

Optical and structural properties of fullerene films doped with cadmium telluride

Composite thin-film structures based on C₆₀/CdTe were prepared by discrete vacuum evaporation in a quasi-closed volume and by vacuum evaporation from a Knudsen cell. The synthesized fullerene samples contained cadmium telluride with a content ranging from 1 to 50 wt %. The morphology and composition of the films were controlled using scanning electron microscopy and energy-dispersive X-ray analysis. The optimum geometry, the total energy, and the spectrum of excited states of the fullerene-cadmium telluride molecular complex were calculated by quantum-chemical methods. The spectral dependences of the photo-luminescence, Raman scattering, extinction coefficient, and refractive index were measured for different compositions. It was found that, in contrast to the spectra of pure fullerene, the luminescence and absorption spectra of the fullerene doped with cadmium telluride exhibit an additional peak in the wavelength range of 600–620 nm. These data were interpreted as the existence of dipole-allowed transitions in the spectrum of excited singlet states of the fullerene due to the interaction with cadmium telluride. The composite films had an increased resistance to degradation under the action of oxygen and water vapor.     

Synthesis and structure study of ordered arrays of ZnSe nanodots

A novel approach is presented for synthesis of ZnSe nanodot arrays by physical vapor deposition on porous aluminum oxide templates with ordered channels. The structure of nanodots was studied by scanning electron microscopy and EXAFS spectroscopy. Data were obtained for the sizes of nanodots in the array and local atomic structure parameters, i.e., the interatomic distances and coordination numbers, in comparison with the data for the ZnSe film synthesized on a smooth surface of nonporous Al₂O₃.