Production of φ Mesons on Nuclear Targets in the Quark–Gluon String Model

Physics of Atomic Nuclei - Experimental data on the production of φ mesons in proton–nucleus and nucleus–nucleus collisions are considered. These data show unusually small...     

Synthesis of novel 1,2-functionally-substituted 6,7-dimethoxy-4-spirocyclo-pentanetetrahydroisoquinolines

1-[(3,4-Dimethoxyphenyl)cyclopentyl]methylamine has been used in the synthesis of 6,7-dimethoxy-4-spirocyclopentane-1,2,3,4-tetrahydroisoquinoline-1-carboxylic acid N-methylamide which is employed in the preparation of novel derivatives with substituents in positions 1,2,6, and 7.     

The features of identifying lines in a diffraction image formed by a widely divergent X-ray beam

A method for identifying lines in a diffraction image formed by a widely divergent X-ray beam and a technique for measuring the crystal structure parameters in the case of asymmetric crystal position have been developed. It is established that, once the distances between a crystal and a photographic plate and between the points of intersection of the hyperbola branches in a diffraction image are known, one can determine the angle between the crystal’s zone axis and the wave vector, which leads to multiwave diffraction. Relations linking this angle with the parameters of two atomic planes are obtained. It is found that, to measure the parameters of atomic planes belonging to a given zone, one can use different sets of crossed hyperbolas formed by radiations K _α and K _β. The measurements and calculations performed for the same sample (Si crystal), mounted symmetrically and asymmetrically, confirm the reliability of the proposed method.     

Production of strange secondaries in high-energy Σ<Superscript>−</Superscript><Emphasis Type="Italic">A</Emphasis> collisions

The WA89 Collaboration experimental data on production of Λ, Σ⁻, Σ⁺, Ξ⁻, Ω⁻ baryons, $ \bar \Lambda $ \bar \Lambda and $ \bar \Xi ^ + $ \bar \Xi ^ + antibaryons in Σ⁻ collisions with C and Cu targets at 345 GeV/c ($ \sqrt {s_{\Sigma N} } $ \sqrt {s_{\Sigma N} } ≈ 25.5 GeV) in the frame of the Quark-Gluon String Model is described. The comparison of the theoretical results with the experimental data is discussed. Finally, some relations among the values of the model parameters obtained with the help of quark combinatorics are presented.     

Spectroscopic study of polycrystalline TiO2 doped with vanadium

The structure of coordination sites (V⁴⁺ ions) and their spatial distribution in the polycrystalline titanium dioxide (rutile) lattice were studied by ESR. It was found that at low degrees of doping, at [V⁴⁺] < 0.5 at.%, the vanadium ions are isotropically distributed in the rutile lattice. At [V⁴⁺] > 0.5 at.% a new microphase with the mixed composition {TiO₂—VO²} is formed. The mixed microphase has a noticeably narrower band gap than the initial TiO₂. Comparison of the photocurrent spectra and the plots of the integral photocurrent vs. vanadium content with the structural data obtained using ESR spectroscopy showed that the formation of the {TiO₂—VO²} microphases deteriorates the photoelectrochemical properties of the modified photoelectrodes. Synthetic procedures interfering the formation of such microphases in the doped rutile are discussed.     

Resolving Controls for the Boundary Approximate Controllability of Sandwich Beams with Uncertainties the Green’s Function Approach

Mechanics of Composite Materials - The boundary approximate null-controllability of an Euler–Bernoulli sandwich beam subjected to a dynamically active distributed load is considered. The...     

Cohomological structure of the conformal anomaly

A cohomological classification of conformal anomalies in the dimension D=6 is given. Different anomaly classes have a common origin from the cohomological standpoint, being equivalent to the Euler density E₆. The descent equation technique is developed for conformal anomalies by analogy with gauge theories. All highest cocycles of the Weyl group are investigated. The general technique for constructing all conformal anomalies from the Weyl density E_2n in arbitrary space-time dimensions is presented. The principal difference between structures of these anomalies in dimensions D=4 and D=6 is demonstrated. A conformally invariant operator (constructed from Riemann and Ricci tensors, scalar curvature, and covariant derivatives) acting on a scalar with zero conformal weight is absent in D=6. Translated from Teoreticheskaya i Matematicheskaya Fizika, Vol. 117, No. 3, pp. 351–363, December, 1998.     

Stochastic model of adsorption of particles on macromolecules at an arbitrary filling

The theory of adsorption of particles on macromolecules is considered. The theory is based on the notion that the adsorption is a discrete Markovian process. In the context of this theory the average number and the variance of the number of ligands adsorbed on macromolecules are calculated exactly. The results are compared with the frequently used approximation where the number of adsorbed particles is smaller than that in the solution. It is shown that for small values of the equilibrium constant the exact and approximate values coincide practically.