Formation of nickel coatings by electrochemical deposition under X-ray irradiation

The influence of X-ray irradiation on the formation of nickel electroplating coatings is studied. The regularities of the nickel electrocrystallization kinetics under X-ray irradiation of different wavelengths, such as the increase in the deposition rate and metal output by the current, are revealed. The features of the structuring of the nickel electroplating coatings under irradiation are revealed. The influence of X-ray irradiation on microhardness, microdeformations, and dislocation structure is estimated. An increase in microhardness and a decrease in microdeformations of nickel coatings with the growth of the radiation energy are established.     

The state of the components in Cu-CeO<Subscript>2</Subscript>-ZrO<Subscript>2</Subscript> catalysts for selective oxidation of CO

Cu-CeO₂ catalysts deposited on a commercial ZrO₂ support have been investigated. The catalyst composition has been optimized: the optimum copper content was found to be 5–10 wt % at a cerium oxide content of 23 wt %. The catalysts were investigated by X-ray diffraction analysis and X-ray photoelectron spectroscopy. According to the X-ray diffraction data, the support consists of the monoclinic ZrO₂ phase and cubic CeO₂ phase with an enlarged lattice parameter, while the catalysts contain CuO. The X-ray photoelectron data indicate the presence of a highly dispersed CuO₂ phase interacting with cerium oxide and zirconia on the surface of the catalyst having the optimum copper content.     

New Method for Measuring the Refractive Index of Flowing Liquid

Optics and Spectroscopy - The necessity of a new method for measuring the refractive index of a turbulently flowing fluid in a pipeline is substantiated. A new method for measuring refractive index...     

Dynamic Vortex States in High-Temperature Superconductors under Pulsed Magnetization

Physics of the Solid State - A vortex system of the Bi-2212 superconductor in an external magnetic field linearly increasing at different rates has been numerically simulated using the Monte Carlo...     

Catalytic Properties of Heteropolytungstates with 3<Emphasis Type="Italic">d</Emphasis> Elements and Their Thermolysis Products

The catalytic properties of the potassium salts of heteropolytungstates with the general formulas K_m[X₂W₁₁(H₂O)O₃₉] (X = Fe³⁺, Co²⁺, and Zn²⁺) and K₅[H₂W₁₁Cr(H₂O)₂O₃₈] with the Keggin anion structure and K_n[XH_nW₆O₂₄] (X = Ni²⁺ and Mn⁴⁺) with the Anderson anion structure and their thermolysis products were studied in the reaction of isopropanol oxidation to acetone by atmospheric oxygen. Changes in their catalytic properties depending on their constituent 3d elements were established. The test heteropolytungstates and the thermolysis products of their potassium salts—phases with the structures of the types of pyrochlore and hexagonal tungsten bronzes—are promising compounds for the preparation of catalysts for organic synthesis reactions. The results of the studies can be useful for the prognostication of the properties of new catalytic systems based on these compounds.     

Calculating the Maximum Density of the Surface Packing of Ions in Ionic Liquids

Russian Journal of Physical Chemistry A - The maximum density of monolayer packing on a graphene surface is calculated by means of molecular dynamics (MD) for ions of characteristic size and...     

The properties of 4′-N,N-dimethylaminoflavonol in the ground and excited states

The mechanism of protonation of 4-N,N-dimethylaminoflavonol and the structure of its protolytic forms in the ground and excited states were studied by electron absorption and fluorescence (steady-state and time-resolved) spectroscopy and with the use of the RM1 quantum-chemical method. A comparison of equilibrium constants and the theoretical enthalpies of formation showed that excitation should be accompanied by the inversion of the basicity of the electron acceptor groups of this compound and, as a consequence, changes in the structure of its monocationic form. An analysis of the spectral parameters of the protolytic 4-N,N-dimethylaminoflavonol forms, however, showed that their structure and the sequence of protonation in the excited state were the same as in the ground state. Changes in the structure of the monocation in the excited state were not observed because of the fast radiationless deactivation of this form and the occurrence of excited state intramolecular proton transfer in aprotic solvents.     

Phase equilibria and the thermodynamic properties of saturated solid solutions of BiTeI,Bi<Subscript>2</Subscript>TeI,and Bi<Subscript>4</Subscript>TeI<Subscript>1.25</Subscript> compounds of the AgI–Bi–Bi<Subscript>2</Subscript>Te<Subscript>3</Subscript>–BiTeI system

The phase equilibria of the Ag–Bi–Te–I system in the part AgI–Bi–Bi₂Te₃–BiTeI is studied in the interval of 500–540 K by means of physicochemical analysis. Thermodynamic properties of phases are determined via EMF. Potential-forming processes occur in electrochemical cells (ECCs) of the C|Ag|glass Ag₃GeS₃I|D|C structure (where C denotes inert (graphite) electrodes; Ag, D denotes ECC electrodes; D denotes four-phase alloys of the AgI–Bi–Bi₂Te₃–BiTeI system; and Ag₃GeS₃I glass is the selective Ag⁺ conducting membrane). Linear dependences of the EMFs of cells Е(Т) in the interval of 505–535 K are used to calculate the values of the thermodynamic functions of BiTeI, Bi₂TeI, and Bi₄TeI_1.25 phases saturated over silver.     

EuroPt-1 catalyst: Radial distribution of electron density X-ray diffraction and EXAFS studies

The supported Pt/SiO₂ (EuroPt-1) catalyst has been studied by the radial distribution of electron density (RDED) and EXAFS techniques. The starting sample of the catalyst was stored in air, not subjected to any further treatment, and contained metal platinum Pt⁰ and platinum oxide PtO in a ～1:2 ratio. An analysis of the EXAFS data was based on three possible structural models of platinum particles. Model 1 suggested that there was one Pt-Pt short contact, which was the same in the bulk of the particles and on the surface. Model 2 considered two different Pt-Pt distances for the particle volume and surface. For model 3, we additionally assumed that the corresponding Debye-Waller factors differed. For the oxidized sample, model 2 was most reliable, and the Pt-Pt distance between the surface atoms was shortened by ～0.14 Å. For the reduced samples, the structural data obtained are consistent with model 3.