Role of aerosil surface in reaction of exciplex formation in the presence of the nonionic surfactant triton X-100

In the formation of a pyrene/N,N-dimethylaninline exciplex solubilized in micelles of the nonionic surfactant Triton X-100, under conditions of adsorption on the surface of Aerosil (pyrogenic silica), the features of the reaction are determined by the restructuring of the Aerosil surface in the aqueous micellar medium and by encapsulation of the fluorophore molecules.Institute of Surface Chemistry, National Academy of Sciences of the Ukraine, 31 Nauka Prospect, Kiev 252039, Ukraine. Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 32, No. 5, pp. 320–323, September–October, 1996. Original article submitted June 16, 1995.     

Investigation of the spectral and angular distribution of gamma radiation of ultrarelativistic electrons in crystals

A technique and experimental apparatus are described for measuring the properties of radiation from relativistic electrons in crystals as a function of frequency and angle. The results of these measurements are compared with calculations and with the results obtained by other workers.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 6, pp. 54–62, June, 1991.     

Charged Particle Trajectories in the MAVR High-Resolution Magnetic Spectrometer

Charged-particle trajectories in the MAVR high-resolution magnetic spectrometer [1] are simulated. The latter has been constructed at the U400 accelerator for purifying the incident beam and identifying the products of nuclear reactions induced by the beams of stable and radioactive nuclei. In this paper we present the MAVRPC software package, aimed at reconstructing the spectrometer focal plane, optimizing the fields of quadrupole and dipole magnets, and estimating the solid-angle acceptance for secondary particles.     

Investigation of the properties of nuclei with extreme neutron excess in the vicinity of neutron magic numbers

Properties of even-even nuclei with extreme neutron excess in the vicinity of neutron magic numbers up to and beyond the neutron drip line (NDL) are calculated by the Hartree-Fock (HF) method using Skyrme forces (Ska, SkM*, Sly4, SkI2, SkP) with allowance for axial deformation and BCS-approximation pairing. It is shown that chains of isotones with the neutron numbers N = 32, 58, 82, 126, 184, and 258 beyond the NDL form peninsulas of nuclei stable with respect to emission of one neutron, and occasionally peninsulas of nuclei stable with respect to the emission of two neutrons. The length of these peninsulas in (N, Z) space depends on the choice of the Skyrme forces, while their locations are at the same N = 32, 58, 82, 126, 184, and 258 and do not depend on the choice of forces. The investigated isotones restore stability beyond the NDL due to the complete filling of subshells with high angular momentum and to the intrusion of corresponding neutron levels in the region of discrete bound states. The stability of the numerical solution to the HF equations for nuclei belonging to the peninsulas of stability is analyzed.     

Experimental and Theoretical In Situ Spectral Magneto-Ellipsometry Study of Layered Ferromagnetic Structures

JETP Letters - The influence of antiadiabatic phonons on the superconducting transition temperature is considered within Eliashberg-McMillan approach in the model of discrete set of (optical)...     

An NMR, DSC, and IR spectroscopy study of the composite formed during low-temperature postradiation polymerization of C2F4 in the presence of a 3D graphene material

By solid-state magic angle-spinning nuclear magnetic resonance spectroscopy (NMR), differential scanning calorimetry (DSC), and IR spectroscopy, polytetrafluoroethylene (PTFE) samples obtained by low-temperature (T = ?196°C) postradiation polymerization of tetrafluoroethylene (C₂F₄) and C₂F₄ mixtures with a 3D graphene material formed by the microwave exfoliation of graphite oxide films (MEGO) have been investigated. It has been shown that the melting point of PTFE in the PTFE-MEGO composite is 332.5°C, which is 8.8°C above the melting point of pure PTFE obtained under the same conditions. According to the measured values of specific enthalpy of melting ΔH _m (51.5 and 45.4 J/g), the degrees crystallinity (x _c) of 0.63 and 0.55 have been calculated for the pure polymer and the composite, respectively. It has been also found that none of the PTFE-containing samples examined has terminal CF₃ groups typical of PTFE prepared by conventional suspension polymerization.