Expedient Strategy for the Synthesis of 5-Acylethynylpyrrole-2-carbaldehydes

5-Acylethynylpyrrole-2-carbaldehydes have been synthesized from the protected pyrrole-2-carbaldehydes by their transition-metal-free topochemical mechanoactivated ethynylation with acylbromoacetylenes in a solid Al₂O₃ medium (room temperature, 6 h, 41–54% yields).     

Polyaniline films electrodeposited on iron from oxalic acid solution: spectroscopic analysis of chemical structure

Journal of Solid State Electrochemistry - Chemical structure of polyaniline electrodeposited on iron from oxalic acid solution has been studied by means of NEXAFS, Raman, and XPS spectroscopies....     

Source Localization by a Partially Calibrated Array in an Uncertain Transmission Channel

A robust Capon-type algorithm is constructed for source localization by a partially calibrated array operating in an uncertain environment. Results of statistical modeling are presented to determine the accuracy of source localization and the probability of correct source detection. Experimental testing of the proposed method is carried out to demonstrate its performance in Ladoga Lake.     

Reconstruction of the Sea Bottom Parameters for Coherent Seismoacoustic Sounding: I. Decision Rules

We have developed an algorithm for reconstructing the geoacoustic parameters of bottom layers using parametric models of the formation of signals reflected from a layered halfspace during coherent sounding of the bottom of a sea shelf. We propose a method for layer-by-layer reconstruction that makes it possible to efficiently search for a solution in the multiparameter space with limited a priori data.     

Scattering of two-dimensional dark quasi-solitons by smooth inhomogeneities in a Bose-Einstein condensate

It is theoretically shown that creation of artificial inhomogeneities allows one to control dynamics of two-dimensional dark quasi-solitons in a Bose-Einstein condensate. A method to calculate trajectories of these quasi-solitons is proposed. It allows control parameters to be selected for the potentials responsible for formation of the Bose gas density distributions required for the scattering through the given angle.     

Possibility of separating spent nuclear fuel components by a plasma method in azimuthal magnetic and radial electric fields

We consider the method of plasma separation of spent nuclear fuel in a system with an azimuthal magnetic field and the electric potential produced by electrodes located in a magnetized plasma. The results of calculation of trajectories of ions simulating uranium and the first peak of its fission products in the oneparticle approximation are described. The effect of the initial position and the initial velocity of ions on their trajectories is analyzed. The conditions ensuring the spatial separation of ions in the groups of masses admissible for practical realization are specified; it is shown that currents on the order of 100 kA through the central conductor and electrostatic potentials on the order of 1 kV are required for this purpose.     

Molecular orientation in electrodeposited polypyrrole films

The molecular arrangement in electrodeposited polypyrrole films was studied by means of linear dichroism in the near-edge X-ray absorption fine structure (NEXAFS) spectra measured at the K absorption edges of carbon and nitrogen. It has been found that the change of the exciting radiation incidence from normal to grazing leads to an increase in the intensity of π*-related resonances with simultaneous decrease in the intensity of σ*-related resonances in the spectra. Similar changes in the spectra measured for both absorption edges indicate a pronounced conjugation of π-bonds in the polypyrrole chains in the grown films. Preferential in-plane orientation of pyrrole rings relative to the substrate surface is observed for all the deposited films. The linear dichroism is more pronounced at the initial stages of deposition (2D growth) than at later stages characterized by “cauliflower”-like morphology of the grown film.     

On the vibrations described by the telegraph equation in the case of a system consisting of several parts of different densities and elasticities

We consider mixed initial-boundary value problems for longitudinal vibrations described by the telegraph equation in the case of a system consisting of several parts with different densities and elasticities but with equal impedances. We consider the cases of control by displacements at both endpoints of the rod, by elastic forces at both endpoints, and by an elastic force at one endpoint and a displacement at the other endpoint. We find closed-form expressions for the solutions of these mixed problems.