Analysis of the stress-strain state of a non-shallow orthotropic cylindrical shell with an elliptical hole

Scientific-Production Organization Sistema, L'vov. Translated from Prikladnaya Mekhanika, Vol. 24, No. 4, pp. 57–63, Ap-il, 1988.     

N-pyrylation of hexahydrocarbazole

4-Methoxypyrylium salts react with hexahydrocarbazole to give 4-(9-hexahydrocarbazoly-pyrylium derivatives. The reaction of the latter with ammonia and hydrazine was investigated.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 347–348, March, 1973.     

Light-induced glass cutting

Theoretical and experimental results on light-induced method for thermal cleaving of brittle materials by the example of silicate glasses are presented. Physical fundamentals of the controlled distribution of thermal fields induced by laser radiation causing compression and tension processes in a material resulting in material cleavage with a zero cut width are developed.     

Crystallite size and magnetic properties of La0.7Mn1.3O3 ± Δ

The results of investigation into nanocrystalline lanthanum manganites La_0.7Mn_1.3O_{3 ± Δ} produced by repeated cold isostatic pressing of a charge material are reported. A powder compact with a crystallite size of 5–7 nm exhibits no magnetic properties, unlike a coarse-grained (20 nm) powder compact.     

Application of the background standard method for the determination of Rb,Sr, Y,Zr, and Nb contents in phosphorites by x‐ray fluorescence

The aim of the present work is to demonstrate the application of the x‐ray fluorescence (XRF) technique to the determination of Rb, Sr, Y, Zr, and Nb contents in phosphorites. The effect of a chemical sample composition on fluorescence intensities of analytical lines has been taken into account using the background standard method. A novelty of the work is the detailed study of a background to choose the background position, free from the spectral line overlaps of the elements presented in the sample. The most suitable background position is the position at the angle 2θ = 29° when using the analyzing crystal LiF(200). During our investigation we faced a problem of choice of Certified Reference Materials (CRMs) for the calibration of the phosphorites. To estimate interelement effects and to choose CRMs for the calibration the intensities were theoretically calculated. The statistical processing of analytical results of the technique is carried out. This technique may be applied to the determination of Rb, Sr, Y, Zr, and Nb contents in the phosphorites. Also, the possibility has been demonstrated to use the XRF technique for geochemical investigations of rocks. Phosphorites of Bokson‐Khubsugul Basin were selected as an example. As a result of the investigation the genetic type of phosphorites was established, which corresponded to the present geodynamical depositional environment. The character of the distribution of Rb, Sr, Y, Zr, and Nb contents in the phosphorites was also studied. Copyright © 2008 John Wiley & Sons, Ltd.     

Dissipative Heating of a Viscoelastic Cylinder under a Load Steadily Moving over Its Surface

The Fourier method is used to find the analytical solutions to two-dimensional quasistatic problems of stationary polyharmonic vibrations and dissipative heating of a linearly viscoelastic cylinder. The influence of the cylinder thickness and the width of the loading area on the thermomechanical state of the cylinder is studied based on numerical data__________Translated from Prikladnaya Mekhanika, Vol. 41, No. 2, pp. 23–32, February 2005.     

Structure, phase transitions, 55Mn NMR, and magnetoresistive properties of La0.6Sr0.2Mn1.2 ? yCryO3 ± δ

The structure and properties of lanthanum strontium manganite perovskites La_0.6Sr_0.2Mn_{1.2 − y} Cr _y O_{3 ± δ} (y = 0–0.3) sintered at 1430°C have been studied by X-ray, resistive, and magnetic (χ_ac and ⁵⁵Mn NMR) methods. The parameter of the rhombohedrally distorted (R $ \bar 3 $ \bar 3 c) perovskite structure decreases with increasing y. The real perovskite structure contains point (anion and cation vacancies) and cluster-type nanostructure defects. The analysis of asymmetrically broadened ⁵⁵Mn NMR spectra has confirmed the high-frequency electron-hole exchange Mn³⁺ ↔ Mn⁴⁺ and local inhomogeneity of their surrounding by other ions and point and cluster-type defects. An increase in the Cr content leads to an increase in the resistivity and the magnetoresistive effect and a decrease in the metal-semiconductor and ferromagnetic-paramagnetic phase transition temperatures (T _ms and T _c ) due to the distortion of the exchange interactions Mn³⁺ ↔ Mn⁴⁺ by chromium ions, vacancies, and clusters. Introduction of Cr decreases the ferromagnetic component and increases the activation energy. The magnetoresistive effect near T _ms and T _c is caused by scattering of charge carriers from intercrystallite nanostructure inhomogeneities of the lattice, and the low-temperature effect is associated with the tunneling on mesostructural intercrystallite boundaries.     

Study of the diffraction scattering 12C + 12C with the excitation of the 12C exotic state 0 2 + (the Hoyle state)

New results from a series of experiments dedicated to the study of the ¹²C exotic state (the so-called Hoyle state) are presented. In spite of the many investigations that have been carried out, the structure of this state (which lies above the threshold for breaking up into three alpha particles) is still unknown. The different models assume that the nucleus has an abnormally large size in this excited state. However, until recently, methods for measuring the radii of unbound states have not been suggested. The best way to solve this problem seems to be by measuring the angular distributions of elastic and inelastic scattering of ¹²C on different target nuclei, and the determination of the radii is based on the fact that, at small scattering angles, the cross sections for direct reactions at high enough energies behave like Frauenhofer diffraction on a black ball. Accordingly, an experiment was performed aimed at measuring the elastic and inelastic angular distributions of ¹²C with an energy of (121.5 ± 0.5) MeV on a ¹²C target. The elastic scattering was measured in the angular range from 18° to 50° in the c.m. system with uncertainty in the angle of measurement equal to Δθ = ± 0.6°. The inelastic cross section was measured for the ¹²C excited state 2⁺ (4.44 MeV) and 0⁺ (7.65 MeV). Estimates were made for the diffraction radii for the ground and excited states. An increase was observed in the radius of the state at 7.65 MeV compared to those of the ground and first excited states.     

Binuclear carbonyl-containing complexes of Rh(i) with bis-(o-hydroxy)- and bis-(o-amino) quinones

Conclusions We synthesized a number of binuclear rhodium complexes that contain bis-(o-hydroxy)- and bis-(o-amino) quinones.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2630–2632, November, 1973.