Parametric X-ray radiation from powders

Parametric X-ray Radiation (PXR) produced in powders has been observed for the first time. PXR spectra were measured under observation angles of 150° and 180° during the interaction of relativistic 7 MeV electrons with a tungsten powder. All the PXR peaks that theoretically can be produced in the studied energy region were registered. The performed absolute comparison of the experiment with the PXR kinematical theory from randomly oriented crystallites showed a good accordance.     

Copper Tetra-4-Carboxyphthalocyanine as a Chemical Additive and Dye for Composites and Polycaproamide

Copper tetra-4-carboxyphthalocyanine was studied as a chemical additive and dye for a polymeric binder of fibrous composites and polycaproamide.     

Probability Characteristics of Passive-Tracer Clusters in a Two-Dimensional Turbulent Medium

We study the evolution of a passive-tracer cluster on the surface of a turbulent medium. Stochastic equations for geometric characteristics of the density distribution of a passive tracer are derived and analyzed. We show that the cluster can be localized in such a way that cluster particles can stay near one another for a long time not obeying the molecular-diffusion law. The conditions of existence of a localization phenomenon in the case of significant anisotropy of the cluster are found along with the probability distributions of geometric properties of the cluster.     

Gas chromatographic, quentum-chemical, and molecular statistical studies of cluster adsorption of water and methanol molecules on hydrophilic surface sites of hydrophobic adsorbents

The comprehensive theoretical and experimental study of the adsorption of water and methanol molecules on active sites (carboxyl and phenol hydroxyl groups) on the graphitized thermal carbon black is performed. It is shown that microclusters formed upon the adsorption of these molecules on such sites are characterized by the cyclic structure comprising 4–5 molecules similar to that whose existence was revealed previously in liquid water and on the surface of silver iodide. The analysis of the studied adsorption clusters demonstrated that the formation of such cycles is governed primarily by the hydrogen bonding; however, a definite role is played also by energy effects associated with the changes in the state of molecular motion during adsorption. It is shown that the generalized Langmuir equation derived from molecular statistical considerations provides for better reproducing of the experimental isotherm within a wider surface coverage range, thus making it possible to consistently interpret data on structural and energetic characteristics of adsorption systems obtained by gas chromatography and quentum-chemical method.