p-Adic string compactified on a torus

U(1) ^xD model with the Villain action on ag-loop generalizationF _g of the Bruhat-Tits tree for thep-adic linear groupGL(2, _p ) is considered. All correlation functions and the statistical sum are calculated. We compute also the averages of these correlation functions forN vertices attached to the boundary ofF _g. When the compactification radius tends to infinity the averages provide theg-loopN-point amplitudes of the uncompactifiedp-adic string theory, in particular forg=0 the Freund-Olson amplitudes.     

Stability of layered coatings under biaxial thermomechanical loading

The three-dimensional problem of stability of layered coatings at normal and high temperatures and small precritical strains is formulated and solved and the characteristic equations are derived. The temperature dependence of the physical and mechanical parameters of specific layered coatings is established experimentally. Three-layer coatings on a homogeneous substrate at different temperatures are considered as an example. Recommendations for establishing the optimal service conditions for layered structural members with coatings are formulated.     

Absorption UV spectroscopy and electronic structure of ionic and tautomeric forms of hydroxy and methoxy derivatives of cytosine and adenine,and of some 5-substituted analogs of pyrimidines

The individual absorption spectra of various ionic and tautomeric species of some derivatives of nucleic-acid components have been determined by computer handling of the summary spectra of these compounds measured at different pH values. These individual spectra have been decomposed into separate bands represented by log-normal curves and corresponding to different electronic transitions. Using the parameter system calculated earlier for the molecules of the vitamin B₆ family, the calculation of the electronic spectra and electronic structure of various ionic and tautomeric species of the molecules studied have been carried out in the π-electron approximation. These properties have also been calculated by the all-valence electronic method CNDOS . The calculated results correlate well with both approximations and with our experimental spectral data. The localization of the molecular electronic excitation studied on the transition to the S₁ and T₁ states is considered in connection with the reactivity in these states.     

The mutual influence of the boundaries of a hole and the faces of a cylindrical shell under distention

We consider the problem of distention of a thin circular cylindrical shell of finite length weakened by a circular slit. On the basis of the complex equations of the theory of cylindrical shells we construct a solution that makes it possible to take account of the influence of the boundaries of the hole and the faces. Using the method of boundary collocations and taking account of the conditions for single-valuedness of the displacements, we reduce the problem to a system of linear algebraic equations. We study numerically the behavior of the membrane stresses as the boundaries of the hole and the faces are moved closer together. Translated fromTeoreticheskaya i Prikladnaya Mekhanika, No. 23, 1992, pp. 45–48.     

Electronic structure of the pyrimidine and purine components of nucleic acids in their ground and lower excited singlet and triplet states

Quantum-chemical calculation of the energies of the electronic transitions and the electronic structures of the neutral and ionic species of the nucleic acids components in their ground and lower excited singlet and triplet ππ* and nπ* states has been carried out in the all-valence-electron approximation CNDO /S . The results of the calculation allow one to identify the most photoreactive sites of the molecules and to consider the dependence of the location of these sites on the ionic state of the molecules. The calculated data are compared with our previous results obtained in a π-electron approximation. The individual absorption spectra of various ionic and tautomeric species of the nucleic acids components obtained by us earlier have been decomposed into bands corresponding to separate electronic transitions. As a rule, there is a good agreement between the calculated data in the two approximations and the experimental results.     

Stability of a laminar half plane of regular structure under uniform compression

Institute of Mechanics, Academy of Sciences of the Ukrainian SSR, Kiev. Translated from Prikladnaya Mekhanika, Vol. 27, No. 8, pp. 16–22, August, 1991.