Structural and optical properties of vacuum-deposited ZnS nanostructures

In this paper some structural, substructural and optical proper- ties of zinc sulfide nanostructures obtained by a CSVS method on bulk ZnSe are investigated. Examination of optical and substructural properties was performed by infrared spectro- scopy and X-ray diffraction, respectively. The results of these studies enabled determination of the dependence of the main structural film parameters (texture, lattice parameters, grain and X-ray scattering domain sizes, and microstrain) on the growth conditions. IR-spectral distributions of transmission coefficient T(n) for bilayered ZnS/ZnSe nanostructures are obtained. When you are citing the document, use the following link http://essuir.sumdu.edu.ua/handle/123456789/3323

Fluoride technology of obtaining REM magnetic alloys and master alloys

Rare earth permanent magnets (REPM) based on neodymium-Fe-boron system are the most promising, since they have the highest magnetic and satisfactory mechanical characteristics. The paper covers physical-chemical principles and shows the results of experimental studies of the process of obtaining REM alloys and master alloys using fundamentally new fluoride technology based on ladle calciothermal REM fluorides and Fe reduction

Terpene analogues of dithiophospate pesticides

New optically active O,O-diterpenyl dithiophosphoric and O-terpenyl aryldithiophosphonic acids were prepared when chiral terpenols such as (1R)-endo-(+)-fenchyl alcohol, (1S)-endo-(-)-borneol, (1R)-(-)-nopol, and (1R,2S,3S,5R)-(+)-isopinocampheol were involved in reactions with tetraphosphorus decasulfide and 2,4-diaryl 1,3,2,4- dithiadiphosphetane-2,4- disulfides. Copyright © Taylor & Francis Group, LLC

Artificial boundary conditions for the linearized Benjamin-Bona-Mahony equation

International audienceWe consider various approximations of artificial boundary conditions for linearized Benjamin-Bona-Mahoney equation. Continuous (respectively discrete) artificial boundary conditions involve non local operators in time which in turn requires to compute time convolutions and invert the Laplace transform of an analytic function (respectively the Z-transform of an holomorphic function). In this paper, we derive explicit transparent boundary conditions both continuous and discrete for the linearized BBM equation. The equation is discretized with the Crank Nicolson time discretization scheme and we focus on the difference between the upwind and the centered discretization of the convection term. We use these boundary conditions to compute solutions with compact support in the computational domain and also in the case of an incoming plane wave which is an exact solution of the linearized BBM equation. We prove consistency, stability and convergence of the numerical scheme and provide many numerical experiments to show the efficiency of our tranparent boundary conditions

Monoterpenoids dithiophosphates. Synthesis and biological activity

O,O-Dialkyldithiophosphoric acids adds at the double bond of the racemic camphene and (+)- limonene in the presence of Lewis acids in accordance with the Markownikoff rule with the formation of Sterpenyl esters of dithiophosphoric acids. The reaction with camphene is accompanied by the rearrangement of camphane structure to that of bornane. Addition of dithiophosphoric acid to (+)-limonene proceeds with the participation of the exocyclic double bond. Toxic and genotoxic properties of the monoterpenoid dithiophosphates were studied. © Pleiades Publishing, Ltd., 2010

Impurity breakdown and terahertz luminescence in n-GaN epilayers under external electric field

We report on the observation and experimental studies of impurity breakdown and terahertz luminescence in n-GaN epilayers under external electric field. The terahertz electroluminescence is observed in a wide range of doping levels (at noncompensated donor density from 4.5×10[sup 16] to 3.4×10[sup 18] cm[sup −3]). Spectra of terahertz luminescence and photoconductivity are studied by means of Fourier transform spectrometry. Distinctive features of the spectra can be assigned to intracenter electron transitions between excited and ground states of silicon and oxygen donors and to hot electron transitions to the donor states.Peer reviewe

Preparation and characterisation of new biomaterials based on chitosan iodide with biologically active dyes

New composite materials were obtained based on chitosan iodide and organic dyes – methylene blue and fuchsine in fucorcin (Castellani liquid) – by using a simple synthetic procedure. The materials were characterised by scanning electron microscopy, X-ray diffraction, temperature-programmed desorption mass spectrometry, infrared spectroscopy and visible and ultraviolet light spectroscopy. The dyes in the composites were distributed uniformly and did not form separate phases. These composites could form structured porous sponges and films and therefore be used in various fields of application. The materials displayed antibacterial activity against antibiotic resistant gram-positive and gram-negative bacteria

РАЗДЕЛЕНИЕ ФТОРИДОВ ЦИРКОНИЯ И ГАФНИЯ СУБЛИМАЦИОННО-СОРБЦИОННЫМ МЕТОДОМ

The process of nuclear grade zirconium tetrafluoride (ZTF) production in a single decomposition stage was proposed and experimentally confirmed. To achieve this goal vapors of the source ZTF has to be run either through the layer of powdery zirconium dioxide with a height of 140–150 mm or above its layer with a length of 1000–1100 mm. The process cascade for the production of nuclear grade pure zirconium tetrafluoride and hafnium tetrafluoride with a hafnium content of over 99 % in a single decomposition stage and without any technological waste was developed and calculated. It was shown that the proposed process cascade for the single stage decomposition and enrichment of zirconium tetrafluoride and hafnium tetrafluoride allows to produce both zirconium tetrafluoride with a hafnium content of up to 0,01 wt.% from the source zirconium tetrafluoride having a hafnium content of 2,0 wt.% and hafnium concentrate containing more than 99 % of hafnium.Предложен и экспериментально подтвержден способ получения тетрафторида циркония (ТФЦ) ядерной степени чистоты за одну ступень разделения. Для этого пары исходного ТФЦ необходимо пропустить внутри слоя порошкообразного диоксида циркония высотой 140–150 мм или над его слоем длиной 1000–1100 мм. Разработан и рассчитан технологический каскад для получения ядерно-чистых ТФЦ и ТФГ с содержанием гафния более 99 % за одну ступень разделения при отсутствии технологических отходов. Показано, что предложенный технологический каскад для разделения и обогащения тетрафторидов циркония и гафния за одну ступень позволяет получить тетрафторид циркония с содержанием гафния до 0,01 мас.% из исходного ТФЦ с концентрацией гафния 2,0 мас.% и гафниевый концентрат с содержанием более 99 % гафния.

Community evaluation of glycoproteomics informatics solutions reveals high-performance search strategies for serum glycopeptide analysis

Glycoproteomics is a powerful yet analytically challenging research tool. Software packages aiding the interpretation of complex glycopeptide tandem mass spectra have appeared, but their relative performance remains untested. Conducted through the HUPO Human Glycoproteomics Initiative, this community study, comprising both developers and users of glycoproteomics software, evaluates solutions for system-wide glycopeptide analysis. The same mass spectrometrybased glycoproteomics datasets from human serum were shared with participants and the relative team performance for N- and O-glycopeptide data analysis was comprehensively established by orthogonal performance tests. Although the results were variable, several high-performance glycoproteomics informatics strategies were identified. Deep analysis of the data revealed key performance-associated search parameters and led to recommendations for improved 'high-coverage' and 'high-accuracy' glycoproteomics search solutions. This study concludes that diverse software packages for comprehensive glycopeptide data analysis exist, points to several high-performance search strategies and specifies key variables that will guide future software developments and assist informatics decision-making in glycoproteomics

Deciphering Heterogeneity in Pig Genome Assembly Sscrofa9 by Isochore and Isochore-Like Region Analyses

Background: The isochore, a large DNA sequence with relatively small GC variance, is one of the most important structures in eukaryotic genomes. Although the isochore has been widely studied in humans and other species, little is known about its distribution in pigs. Principal Findings: In this paper, we construct a map of long homogeneous genome regions (LHGRs), i.e., isochores and isochore-like regions, in pigs to provide an intuitive version of GC heterogeneity in each chromosome. The LHGR pattern study not only quantifies heterogeneities, but also reveals some primary characteristics of the chromatin organization, including the followings: (1) the majority of LHGRs belong to GC-poor families and are in long length; (2) a high gene density tends to occur with the appearance of GC-rich LHGRs; and (3) the density of LINE repeats decreases with an increase in the GC content of LHGRs. Furthermore, a portion of LHGRs with particular GC ranges (50%–51 % and 54%–55%) tend to have abnormally high gene densities, suggesting that biased gene conversion (BGC), as well as time- and energy-saving principles, could be of importance to the formation of genome organization. Conclusion: This study significantly improves our knowledge of chromatin organization in the pig genome. Correlations between the different biological features (e.g., gene density and repeat density) and GC content of LHGRs provide a uniqu