Knockout of deuterons and tritons with large transverse momenta in <Emphasis Type="Italic">pA</Emphasis> collisions involving 50-GeV protons

Formation of the d and t cumulative light nuclear fragments emitted from the nucleus with large transverse momenta at an angle of 35° in the laboratory frame is investigated. The data on collisions of 50-GeV protons with the C, Al, Cu, and W nuclei are collected using the extracted proton beam of the IHEP accelerator and the SPIN detector. The results indicate that the dominant contribution to formation of nuclear fragments comes from the local process of direct knockout from the nucleus.     

Ab initio study of the structure and stability of AcF n (3 ? n)+ of complexes (n = 1?7)

The structural and energetic characteristics of AcF _n ^{(3 ? n)+} complexes (n = 1?7) have been calculated by the ab initio RHF and MP2 methods.     

Dielectric properties of pyrogenic silicon dioxide

The dielectric characteristics of pyrogenic silicon dioxide were measured, and a theoretical analysis of the change of the dielectric properties of pyrogenic silicon dioxide was carried out with due regard for the surface conduction of water on its particles. A model of a two-layer particle was chosen as the theoretical model. It was shown that the choice of such a model makes it possible to explain experimentally the relaxation maximums of the dielectric losses observed in the frequency range 10⁵–10⁷ Hz.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 24, No. 5, pp. 619–622, September–October, 1988.     

Generalized green operator of a boundary-value problem with degenerate pulse influence

We establish necessary and sufficient conditions for the solvability of inhomogeneous linear boundaryvalue problems for systems of ordinary differential equations with pulse influence in the case where the number of boundary conditions is not equal to the order of the differential system (Noetherian problems). We construct a generalized Green operator for boundary-value problems not all solutions of which can be extended from the left endpoint to the right endpoint of the interval where these solutions are constructed.     

Synthesis and x-ray diffraction study of 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-n-acetic acid dihydroperchlorate

The dihydroperchlorate of 5,5,7,12,12,14-hexamethyl-1,4,8,11-tetraazacyclotetradeca-N-acetic acid (I) was obtained by the exchange reaction of the dihydrobromide with silver perchlorate. A planar structure of the ligand molecule with methyl and CH₂COOH groups that deviate from the plane of the macroring was established as a result of x-ray diffraction analysis. Numerous hydrogen bonds with the participation of a carboxy group, amino nitrogen atoms, and crystallization water molecules were detected.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1572–1575, November, 1992.     

Influence of electron donor molecules on the properties of aqueous dispersions of graphite oxide

High resolution PMR has been used to study the interaction of electron donor molecules (EDM) (acetone, acetonitrile, pyridine (Py), and dimethylsulfoxide (DMS)) with the hydrate surface structures of graphite oxide.It has been found that only relatively strong EDM (pyridine and DMSO) can destroy the hydrogen-bonded poly-aqua-associates between the graphite oxide layers. A peculiar effect of Py manifests itself in the direct interaction of its molecules with the structural OH groups of the graphite oxide, and of DMSO in the formation of sorption-molecular complexes on the surface of the first hydrate layer, thus screening the solid graphite oxide phase from the bulk of the solution. Acetone and acetonitrile have no noticeable effect in the system.Institute of the Chemistry of Surtaces, Academy of Sciences of the Ukrainian Kiev. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 27, No. 2, pp. 201–205, March–April, 1991. Original article submitted July 7, 1989.