Investigation of the parameters of the vibrational absorption bands of impurity CNO− ions in KCl and KBr crystals

Journal of Applied Spectroscopy -     

Implementation of the finite-element method in the numerical package front for calculation of supported thin-walled structures

The application of the FRONT package for calculation of supported thin-walled structures is considered. The main focus is on the specific features of the package which permit using the finiteelement method to analyze large problems for complex structures. Issues of automatic computation are considered. The high computational efficiency of the package is illustrated by some examples.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 60, pp. 44–47, 1986.     

Connection of the solution of a stochastic differential inclusion with the solution of an ordinary differential equation

The equivalence of the solvability of a stochastic differential inclusion and an ordinary differential equation is established and the connection between the solutions is clarified.Translated from Teoriya Sluchainykh Protsessov, No. 16, pp. 48–55, 1988.     

Effect of a conical break of delta-wings on the aerodynamic characteristics

The results of experimental investigations of the aerodynamic coefficients and the pressure on the windward face of delta-wings with a conical break are given. A comparison between the magnitudes of the aerodynamic quality of delta-wings with a conical break and models of a wing-cone with a -shaped symmetrically grouped scheme is carried out at a Mach number of 5.96.Translated from Izvestiya Akademii Nauk SSSR, Mekhanika Zhidkosti i Gaza, No. 6, pp. 100–104, November–December, 1976.     

Structure of lanthanum prepared by quenching from a liquid state

The structure of lanthanum quenched from a liquid state at cooling rates of 2.5 × 10⁵–10⁷ K/s is investigated. It is shown that a mixture of the face-centered cubic β-La phase stable above 583 K and the metastable lanthanum modification with a seven-layer hexagonal lattice consisting of alternating atomic layers ABCABAC… is formed in rapidly cooled foils. A mechanism is proposed for the formation of the metastable polytype, according to which the polytype is formed as a result of saturation of the main β-phase with well-ordered stacking faults.     

Comparison of magnetoreflection from CoFe-Al<Subscript>2</Subscript>O<Subscript>3</Subscript> multilayer and granular films in the infrared spectral region

The paper reports on a study of light reflection and of the magnetorefractive effect in CoFe-Al₂O₃ multilayer and granular films in the IR region at λ = 2.5–25 μm. These films exhibit a noticeable tunneling magnetoresistance of 5–8%. It has been found that the spectra of the magnetorefractive effect have features at λ ≈ 6.7 and ≈8.1 μm originating from phonon mode excitation in the dielectric matrix. It has been established that the magnitude of the magnetorefractive effect exceeds 2.5% for multilayer films, a value substantially larger than that for granular ones. Magnetoreflection has been analyzed for two film systems with roughly equal tunneling magnetoresistance. It has been shown that magnetoreflection for granular films can be described in a first approximation by the modified Hagen-Rubens relation, while the enhanced effect exhibited by multilayer films requires inclusion of interference of the magnetooptical response.     

Inhibition of highly purified porcine kidney Na,K-ATPase by steroid glycosides of the spirostan and furostan series and a study of structure-activity relationships

A comparative investigation has been made of the action of 14 steroid glycosides of the spirostan and furostan series on highly purified Na,K-ATPase from the medullary layer of porcine kidneys (90% purity in terms of protein). It has been shown that alliospirosides A, B, and D, isolated from the collective fruit ofAllium sepa L., are capable of inhibiting the activity of the Na,K-ATPase The inhibition of the activity of the transport enzyme by alliospirosides A and B is of the uncompetitive type and by alliospiroside D of the competitive type. It is desirable to test alliospirosides on the intact organism.Institute of Physiology, Academy of Sciences of the Republic of Uzbekistan. Institute of the Chemistry of Plant Substances, Academy of Sciences of the Republic of Uzbekistan. Translated from Khimiya Prirodnykh Soedinenii, No. 4, pp. 558–566, July–August, 1993.     

Chiral β-hydroxycarbonyl compounds based on (−)-menthone: structure and behavior in liquid crystalline systems

It has been established by X-ray structural analysis that 2-(1-biphenyl-4-yl-1-hydroxy)methyl-p-menthan-3-one, one of the products of the reaction of (–)-menthone triisopropyloxytitanium enolate with 4-phenylbenzaldehyde, has a 1R,2S,4S,1S configuration. In crystals, this -hydroxyketone adopts a chair conformation with equatorial methyl and isopropyl groups and an axial 2-(1-biphenyl-4-yl-1-hydroxy)methyl substituent. Unlike the stereoisomeric compound with the 1R,2S,4S,1S configuration, the exocyclic fragment of which has an intramolecular >C=O...H-O- hydrogen bond in crystals and solutions, in the crystals of the 1R,2S,4S,1S ketol under study, molecules are linked by a network of cooperative -O-H...O-H...O-H... hydrogen bonds. Based on the results of molecular mechanics calculations and experimental data of¹H NMR and IR spectroscopy, conformations of molecules of this compound, which are in equilibrium in solution, have been characterized. Based on data on spatial structures of stereoisomeric -hydroxyketones and the character of H-bonds formed by these compounds, the characteristic features of the effect of these chiral alloying additives on the supramolecular structure and macroscopic properties of liquid crystalline systems have been interpreted.The results of a study of stereoselectivity of the reactions of different (–)-menthone enolates with aromatic aldehydes will be published later.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 7, pp. 1247–1255, July, 1995.The work was supported by the Foundation for Basic Research of the State Science and Engineering Committee of Ukraine (Project No. 93-3.2/75).