Investigation of molecular motions and interprotein interactions in solutions by NMR and TDDS

Applied Magnetic Resonance - Non-selective NMR relaxation of protein and water protons at various resonance frequencies as well as Time Domain Dielectric Spectroscopy (TDDS) were applied to study...     

Luminescent characteristics of tetraphenylporphyrin and its derivatives with lutetium

The spectral and luminescent characteristics of new tetraphenylporphyrin derivatives that contain the lutetium atom in their structure are studied in comparison with the most completely studied unsubstituted tetraphenylporphyrin and its complex with zinc. The luminescence quantum yields in liquid and frozen solutions are measured. The specific features of luminescent characteristics of these compounds and their possible applications are discussed.     

The electrokinetic properties of latex particles: comparison of electrophoresis and dielectrophoresis

A comprehensive study of the AC and DC electrokinetic properties of submicrometre latex particles as a function of particle size and suspending medium conductivity and viscosity is presented. Electrophoretic mobility and dielectrophoretic cross-over results were measured for particle diameters ranging from 44 to 2000 nm. The zeta potentials of the particles were calculated from the electrophoretic mobility data for different suspending medium conductivities, using various models, with and without the inclusion of surface conduction. The dielectrophoretic data was analysed to derive values for the Stern layer conductance and zeta potentials.     

Photonics of zinc complexes of 3,3′-bis(dipyrrolylmethenes)

We measure the spectral luminescence characteristics (absorption, fluorescence, lasing, phosphorescence, and luminescence excitation spectra; fluorescence and phototransformation quantum yields; lifetimes of long-lived radiation) and estimate the fluorescence radiation constants and lifetimes for new synthesized binuclear bihelical complexes of zinc(II) with 3,3′-bis(dipyrrolylmethenes) of different structure in liquid and solid solutions. We discuss possible applications of these compounds.     

Simulation of Accelerated Particle Diffusion in Collisionless Shocks with an Admixture of Heavier-than-Hydrogen Ions

Technical Physics - We report on the results of hybrid simulation of diffusive shock acceleration of ions with different charge-to-mass ratios in quasi-parallel collisionless shocks. We consider a...     

Effect of molding conditions on the structure and properties of polyformaldehyde

The effect of molding conditions-melt temperature, dwell time in molten state, and cooling rate-on the structure and mechanical properties of polyformaldehyde is investigated.Mekhanika Polimerov, Vol. 3, No. 5, pp. 782–786, 1967     

Spectral-kinetic characteristics of lutetium-containing tetrapyrroles

The spectral-kinetic characteristics of the triplet states of tetraphenylporphyrin and triphenylcorrole complexes with an aminopolycarboxylic acid (EDTA or DTPA) or its complex with lutetium as a substitute and the corrole complex with Ga(III) as the central atom have been studied. The transient absorption spectra of the complexes in the triplet excited state (effective maximum at 460–470 nm) and the rate constants of triplet quenching by oxygen at room temperature (2 × 10⁸–7 × 10⁸ L mol^?1 s^?1) have been measured. The quantum yields (0.44–0.55) and the molar absorption coefficients of the triplet state (log ?_T = 4.81–4.89) have been determined for some of the derivatives. The efficiency of population and deactivation kinetics of the triplet states are determined by the structure of the porphyrinoid, in particular by the central ion, and depends slightly on the presence of a heavy atom at the periphery of the molecule. Possible uses of the new compounds for designing various optical devices are discussed.     

Acid-base properties and phototransformations of complexone(ate)-substituted tetraphenylporphyrin

The spectral luminescent properties of series of tetraphenylporphyrin derivatives containing complexone-substituent in one of phenyl cycles or its complex with rare earth ion (Lu(III) or Gd(III)) are studied. The basicity of compounds in the ground and electronically excited states are investigated, and the quantum yields of phototransformations under pulsed radiation are measured. The relationship between the photochemical stability of the compounds and their acid-base properties is discussed.     

Effect of external pressure on the physicochemical and mechanical properties of polymers

The behavior of crystalline polymers obtained by molding at high pressures has been investigated. External pressure can promote or retard polymer crystallization processes, depending on its intensity. Comparison of various physicochemical and mechanical properties of specimens obtained at different external pressures shows that the corresponding curves have two maxima: one at 200–800 kgf/cm² and another on the narrower interval between 1300 and 1500 kgf/cm². The position of the first maximum is associated with the molecular weight distribution and the flexibility of the polymer chain, and position of the second is determined by the chemical nature of the polymer. The data obtained help to make possible a rational choice of polymer processing methods in which pressure is involved.Mekhanika Polimerov, Vol. 4, No. 2, pp. 200–204, 1968     

Electroless Nickel and Copper Plating of Carbon Fibers with the Use of Sulfur-containing Reducing Agents

The fundamental aspects of electroless nickel and copper plating of carbon fibers with the use of sodium hydroxymethane-sulfinate and thiourea dioxide as reducing agents were studied.