Esters ofβ -ketophosphonic acids. VII. The products of the reaction ofα-chlorocyclohexanone with the diethyl ester of ethylphosphonous acid and the sodium salt of the monoethyl ester of ethylphosphonous acid

Summary The action of diethyl ethylphosphonite on-chlorocyclohexanone gives cyclohexen-1-yl-1 -ethyl ethylphosphonate, Cyclohenen-1-yl-1-ethyl ethylphosphonate is also obtained by the action of sodium monoethyl ethylphosphonite on a-chlorocyclohexanone.     

Calculation of the parameters of vacuum-ultraviolet emission of excimers in the plasma of a barrier discharge in a krypton-xenon mixture

The intensities of vacuum-ultraviolet emission of excimers in a krypton-xenon mixture are calculated in terms of the homogeneous model of a barrier discharge. The mechanisms of the formation of excimer molecules are investigated at different xenon concentrations. The obtained dependences of the efficiency of vacuum-ultraviolet emission on the reduced electric field E/N (where E is the electric field strength and N is the particle concentration of the gas) and the xenon content exhibit a plateau and a subsequent steep decline. The efficiency of vacuum-ultraviolet emission reaches a maximum at the plateau when the xenon content δ is approximately equal to 40%. The concentrations of xenon excimers can be as high as 10¹⁴–10¹⁵ cm^?3. This is comparable to the concentrations in a barrier discharge in pure xenon.     

Investigation of the phase diagram and the determination of synthesis conditions of volume amorphous alloys in the Cu-Ni-Zr system at 1123 K

The phase equilibria in the Cu-Ni-Zr system in a field enriched by zirconium at 1123 K were investigated by the methods of X-ray and electron-probe microanalysis, microdurometry, and scanning calorimetry. A fragment of the isothermal section of the given system was constructed and the borders of areas of homogeneity of double phases of the Ni-Zr and Cu-Zr systems were defined. It was established that the double compounds NiZr and NiZr₂ dissolve up to 33 and 12 at % Cu, respectively, and CuZr and CuZr₂, dissolve up to 7 at % Ni.     

Hydrothermal synthesis of efficient TiO<Subscript>2</Subscript>-based photocatalysts

We carried out a thorough study of the micromorphology, physicochemical properties, and photocatalytic activity of nanocrystalline anatase powders formed during the hydrothermal treatment of titanyl sulfate solutions of various compositions. A new procedure is proposed for the hydrothermal synthesis of nanocrystalline anatase having specific surface areas of ∼50 m²/g and photocatalytic activities exceeding the activity of the commercially available Degussa P25 formulation.     

IR and NMR spectra,intramolecular hydrogen bonding and conformations of para-tert-butyl-aminothiacalix[4]arene in solid state and chloroform solution

It is demonstrated that dissolution of aminothiacalix[4]arene in chloroform results in transformation of 1,3-alternate conformation, adopted in single-crystal and bulk polycrystalline solids, to the pinched-cone form. This conformer is stabilised by the intramolecular hydrogen bonds of two distal amino-groups acting as H-donors with another two amino moieties that appear as H-acceptors. The H-bonds cause quite small (ca. 10–20 cm^?1) red shift of the IR bands of the NH₂ stretching vibrations, which suggests rather weak NH?N hydrogen bonding. This latter is sufficient to stabilize the pinched-cone conformation in the chloroform solution, but the energy gap between the pinched-cone and other conformations is small, and solid-state intermolecular forces easily overcome it, leading to realisation of the 1,3-alternate conformer. The comparison of the DFT computed and experimental vibrational and NMR spectra demonstrates good quality of present quantum-chemical computations, allows complete interpretation of the spectra and reveals simple IR and NMR spectroscopic markers of the conformers of aminothiacalix[4]arenes.     

Effective synthesis of 2,3-<Emphasis Type="Italic">seco</Emphasis>-2,3-dicarboxyplatanic acid

An effective method for preparing triterpene 2,3-seco-2,3-diacids by ozonolysis of 2-exomethylene-substituted derivatives of betulonic acid and 28-oxoallobetulone was proposed.     

Inter‐elemental correlations in liver and lung tissue of rats with alimentary adiposity (SRXRF)

The distribution of adiposity steadily grows all over the world. The reasons of the adiposity increase, especially in the developed countries, are not well understood. In particular, the role of lungs in the development of adiposity is not clear. There are many enzymes in the lungs (as well as in the liver), providing the metabolic processes on a high level. Additionally, lung is the first organ which lipids are delivered to with blood after the food intake. The data on the inter‐elemental correlations in the lungs (concerning the alimentary adiposity) are not found in the literature. Thus, the investigation of trace element status of lungs and liver after the fatty food intake is expedient. The experiments were carried out on the adult nonlinear Wistar rats. Two series of the experiments were conducted with control (normal weigh) and animals with adiposity. Each of these series was subdivided into two groups: animals not having food (before the sacrifice) and receiving lard. The results obtained show that the metabolic changes under the alimentary adiposity of experimental rats are accompanied by the redistribution of inter‐elemental correlations in the liver and in the lungs either. The greatest number of strong correlations is observed in case of starving animals of control group. Copyright © 2012 John Wiley & Sons, Ltd.     

Investigation of the conditions of efficient I*<Subscript>2</Subscript> (342 nm) luminescence in a barrier discharge in a Kr-I<Subscript>2</Subscript> mixture

The energy and spectral characteristics of a barrier discharge in a mixture of iodine vapor with krypton have been investigated theoretically and experimentally. The emission spectrum consists of the single I*₂ molecular band D′ → A′ peaking at 342 nm, the iodine resonance line at 206.2 nm, and the group of bands corresponding to iodine emission. The highest intensity of the I*₂ (342 nm) band was obtained at a mixture pressure near 450 Torr. A mean output power and an efficiency of 550 mW and 1.6%, respectively, have been achieved. It is shown that, for the I₂ barrier-discharge excilamp, the homogeneous, rather than filamentary form of discharge glow is optimal from the viewpoint of the highest mean output power. The maximal calculated value of the emission efficiency for the 342-nm band was 5%. The main processes determining energy losses in plasma have been found, and ways to increase the efficiency of emission in the D′ → A′ band of the I*₂ molecule have been proposed.     

Physicochemical Modeling of Sulfide Oxidation Processes in Tailing Dumps of the Kavalerovsky District and Their Impact on the Hydrosphere (Primorsky Krai)

Oxidation of tailings in the tailing dump of Vysokogorskoe deposit (Kavalerovsky district) in the temperature range from 0 to +45°C was simulated with successive exclusion of each of the sulfide minerals present therein (pyrite, pyrrhotite, galena, sphalerite, arsenopyrite, and chalcopyrite). The Eh-pH parameters for anthropogenic mineral formation were determined at different host rock–sulfide ratios (95: 5, 90: 10, 80: 20, 60: 40, 40: 60, 20: 80) in the tailings. Crystallization of supergene minerals was analyzed, qualitative and quantitative ionic compositions of solutions were determined, and their impact on the hydrosphere was assessed.     

A study of the thermal decomposition of layered perovskite-like oxides ANdTiO4 and A2Nd2Ti3O10 (A = Na,K)

The thermal stability of cation-ordered perovskite-like layered titanates ANdTiO₄ and A₂Nd₂Ti₃O₁₀ (A = Na, K) is studied in the temperature range of 900–1400°C. The structural chemical mechanism of their thermal decomposition is established. A comparative analysis of the thermal stability of compounds with different thicknesses of the perovskite layer and different nature of the alkali cation is performed. The observed thermal behavior is explained from crystal chemical standpoints.