Investigation of surface topography, morphology and structure of amorphous carbon films by AFM and TEM

Morphology and structure of amorphous carbon films deposited with a pulsed arc source (LASER-ARC) have been studied using microscopical methods (SEM, TEM and AFM), electron diffraction and spectroscopical investigation (EELS). The parameters of the arc source and the deposition conditions (substrate temperature) influence morphology and structure of deposited amorphous carbon films. Especially the incorporation and growth of particles, embedded in the film have been investigated. By particle analysis using an optical microscope a majority of particles that is smaller than 500 nm has been determined. The morphology has been also demonstrated similar by AFM and TEM images. Their number and size of particles is strongly influenced by the deposition temperature. The structure of amorphous film is characterized by the EELS-spectra, but the particle structure was not detectable.     

A shape model for the twisting power of chiral solutes in nematics

The twisting power of chiral probes in nematics is interpreted in terms of a shape model, in which the surface elements of the solute molecules tend to align with the local director. The theoretical treatment is based on a previous approach, suitable for relating order parameters in nematics to molecular shape, and leads to the definition of a molecular pseudo-tensor whose orientational average determines the pitch and handedness of the helical macrostructures. Results of numerical calculations performed for distorted biphenyl and binaphthyl molecules are in agreement with the experimental results.     

Spectroscopic investigation of Pt—methanol interface in perchloric acid medium by sum-frequency generation

We recorded vibrational spectra of the CO poison resulting from the electrochemical decomposition of CH₃OH on platinum by sum-frequency generation using the infrared free electron laser CLIO. At high CH₃OH concentration (0.1 M) in the electrolyte, both multi-bonded and linearly bonded CO are equally present. At lower CH₃OH concentration (0.004 M), the multi-bonded species is predominant. The CO poison still remains on the surface at potentials (0.05 V/NHE) close to the hydrogen evolution onset.     

Advanced in the synthesis of heterocyclic compounds from aliphatic nitro derivatives. A review

The literature on the synthesis of heterocyclic compounds from aliphatic nitro derivatives in the past decade has been summarized.Moscow State Textile Academy, 117918, Moscow. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1299–1336, October, 1994. Original article submitted October 6, 1994.     

Lattices of processes for graphs

The structure of the lattice of processes of a finite digraph with entries is investigated. Necessary and sufficient conditions for the isomorphism of a given lattice to the lattice of processes of a certain digraph are obtained. Bibliography: 5 titles. Translated by K. V. Shakhbazyan. Translated fromZapiski Nauchnykh Seminarov POMI, Vol. 202, 1992, pp. 135–153.     

Collisions for the quantum Coulomb Hamiltonian

We study the propagation of phase space singularities for the time dependent Schrödinger equation with potential having Coulomb-type singularities in space dimension equal tothree. We prove that the singularities (frequency set) of the solution are reflected by a Coulomb center exactly as in the classical problem, i.e. the frequency set follows theregularized trajectories of Classical Mechanics after a collision.     

Method of fictitious regions for second-order quasilinear elliptical equations

We consider the application of the fictitious region method to solve the first and second boundary-value problems for a second-order quasilinear elliptical equation. Rate of convergence bounds are obtained for two versions of the fictitious region method.Translated from Vychislitel'naya i Prikladnaya Matematika, No. 56, pp. 7–14, 1985