New organic metals based on ET and D8-ET with polymeric metal containing anions

New deuterated organic salts based on (D₈-ET), namely κ-(D₈-ET) 4(HgBr₂Hg₂Br₆), κ-(D₈ -ET)₂ [Hg(SCN)₂Br] and (D₈ -ET)₄[Hg(SCN)₂Cl]₂ were synthesized. Crystal structure of D₈ -ET salts is compared with that of nondeuterated analogs H₈ -ET ones. The temperature dependences ofconductivity are studied for all the salts. κ-(D₈-ET)₄(HgBr₂Hg₂Br₆) is shown to become a superconductor at pressure of ≈300 bar.     

Stress waves in the coupling zones of composite shells of revolution

The problem of the axisymmetric pulsed deformation of a composite shell of revolution and complex geometric shape is solved in the two-dimensional statement. The problem was solved numerically using the Wilkins explicit finite-difference scheme. The results obtained from the one-dimensional and two-dimensional theories, on the basis of which it is concluded that for ultrashort-term loadings with a duration of approximately 10^–1–10^–2 sec, the influence of stress risers is manifested only in the immediate proximity of points of abrupt change in the body's geometry (corner points), are compared. Here, the stress calculation must be performed in accordance with two-dimensional equations, since the onedimensional equations yield values on the low side in certain cases. In sections that are 1 mm and more distant from the corner points, it is possible to use the one-dimensional theory, since the error in stresses, which is obtained in this case, goes into the factor of safety.Institute of Strength Problems, Academy of Sciences of the Ukrainian SSR, Kiev. Moscow Institute of Thermotechnics. Translated from Problemy Prochnosti, No. 10, pp. 68–71, October 1989.     

Oxidation of CO on the Cu–Co–Fe oxide system applied on carbon nanotubes synthesized on Co<Subscript>2</Subscript>O<Subscript>3</Subscript>

Physicochemical characteristics of carbon nanotubes synthesized on Co₂O₃ and oxide Cu–Co–Fe catalysts on their base applied in the CO oxidation reaction have been investigated. It is shown that the deposition technology of the active mass, which, according to the X-ray phase analysis, is a mixture of the Cu₂(OH)₃NO₃ and CuO phases, strongly influences the activity of the Cu–Co–Fe/CNT catalysts. The greatest amount of the Cu₂(OH)₃NO₃ phase is observed in the catalysts produced by a single deposition of the active component on carbon nanotubes, which according to the thermodesorption mass spectroscopy, contributes to the formation of active centers with the lower activation energy of the CO₂ desorption and the reaction of the CO oxidation proceeds at a considerably lower temperatures. The TEMdata indicate that at the step-by-step deposition of the active mass in the surface layer the formation of the massive agglomerates, which are inhomogeneously located on the disordered structures of nanotubes, and this unfavourably affects the catalytic properties of Cu–Co–Fe/CNT catalysts.     

Features of accelerated electron beam formation in LHCD experiments on FT-2 tokamak

In experiments with lower hybrid current drive (LHCD) on the FT-2 tokamak, lower hybrid (LH) waves have been successfully used for the first time to ensure effective additional heating of plasma electrons from 450 to 600 eV (I _Pl = 32 kA, Δt _RF = 14 ms, P _RF = 100 kW, F = 920 MHz). Several factors influencing the efficiency of plasma heating have been discovered. In particular, significant growth of radiation losses in the LHCD regime has been found, which is probably related to an increase in the intensity of synchrotron radiation from accelerated electrons. The increase in this intensity in the 53–156 GHz frequency range was accompanied by short spikes of microwave radiation, which were observed only in a narrower frequency range (53–78 GHz) and apparently resulted from interaction of a runaway electron beam with significant local mirrors of toroidal magnetic field. A model of the additional heating of plasma electrons due to absorption of the microwave radiation generated by a beam of accelerated electrons is proposed.     

Modeling the phase-contrast X-ray tomography imaging of medical samples

A package of applied programs for calculating phase-contrast images of three-dimensional samples has been created. The package was applied to model two tomography experiments in medical samples. Using the results of the calculations, the possibilities of the practical application of these methods are discussed.     

The Matthew Effect in citing the papers of Russian scientists published abroad

The scientificometric aspect of the “Matthews Effect,” i.e., the difference in the citations of the papers of Russian and foreign scientists published in the same publications, is studied. Publications in foreign journals on physics and chemistry are considered. The “Matthew Index,” which characterizes nonuniform distribution of citations over countries, is calculated. A conclusion on the poor “competitiveness” of Russian articles in chemistry and inadequate conformance of publications in physics to the world level is made.     

One-dimensional photonic crystal based on nanocomposite of metal nanoparticles and dielectric

One-dimensional photonic crystal made of nanocomposite of metallic nanoparticles and dielectric is investigated. Splitting of photonic band gap into polaritonic and structure band gap and their fusion are predicted. The different behavior of structure gap with variation of nanoparticle concentration is observed. This behavior is determined by relative arrangement of structure and polaritonic gaps in frequency scale. Considered effects give new possibilities for creating photonic crystals with predefined properties.