Pulse cathodo- and thermoluminescence of alumina ceramic with manganese

Alumina ceramics with manganese in concentration range 0.001-18 wt. % are synthesized. Luminescent properties of obtained ceramics at temperatures 1500-1700°C of sintering in vacuum are investigated. An increase in the manganese concentration leads to quenching of the pulse cathodoluminescence band at 420 nm and the main dosimetric peak at 460 K. The intensity of luminescence in the 676 nm band at manganese concentrations of more than 1 wt. % and the TL yield for all the observed peaks increase when annealing temperature rises. Sublinear increase in TL intensity with a growing dose is observed in the range of 3-1000 Gy in 460 and 620 K peaks. © Published under licence by IOP Publishing Ltd.The reported study was funded by RFBR according to the research project № 18-33-00085

Time-dependent correlation function of the Jordan-Wigner operator as a Fredholm determinant

We calculate a correlation function of the Jordan-Wigner operator in a class of free-fermion models formulated on an infinite one-dimensional lattice. We represent this function in terms of the determinant of an integrable Fredholm operator, convenient for analytic and numerical investigations. By using Wick's theorem, we avoid the form-factor summation customarily used in literature for treating similar problems.Comment: references added, introduction and conclusion modified, version accepted for publication in J. Stat. Mec

Determination of the Operating Time and Residual Life of Self-propelled Mine Cars of Potassium Mines on the Basis of Integrated Monitoring Data

Statistical data on the reliability of self-propelled mine cars (SPMC), operating in the potassium mines of the Verkhnekamskoye potassium and magnesium salts deposit are analyzed. Identified the main nodes that limit the resource SPMC. It has been proven that the most common failures of self-propelled cars are the failure of wheel hubs, bevel gears and traveling electric motors. The analysis of the system of maintenance and repair of mine self-propelled cars. It is indicated that the planning and preventive system of SPMC repairs is characterized by low efficiency and high material costs: car maintenance is often carried out upon the occurrence of a failure, which leads to prolonged downtime not only of a specific haul truck, but of the entire mining complex. A method for assessing the technical condition of the electromechanical part of a mine self-propelled car by the nature of power consumption is proposed. This method allows you to control the loading of the drives of the mine self-propelled car, as well as to assess the technical condition of the drives of the delivery machines in real time. Upon expiration of the standard service life of a mine propelled car specified in the operational documentation, its further operation is prohibited and the car is subject to industrial safety expertise. As part of the examination, it is necessary to determine the operating time and calculate the service life of a mine self-propelled car outside the regulatory period. A method has been developed for determining the residual service life of mine car on the basis of instrumentation control data in the conditions of potash mines

Synthesis and Research of Alumina Ceramics Properties

Received: 27.10.2020. Revised: 18.12.2020. Accepted: 18.12.2020. Available online: 21.12.2020.This article belongs to the PCEE-2020 Special Issue.The article describes in detail alumina powder synthesis by different methods at varying parameters. The technique of obtaining ceramics and the research of the optical properties for determining the materials with the maximum luminescence efficiency is presented. The concentration of the luminescence intrinsic centers and various defects differ for ceramics synthesized by different methods. It is determined that ceramics based on the powder synthesized by a sol-gel method has the maximum thermoluminescence intensity in the Fcenter peak, whereas for the peak of 360 °C it is obtained with the powder prepared by precipitation of aluminum nitrate with a PEG-20000 stabilizer.This work was financially supported by the Russian Science Foundation, project No. 18-72-10082

Synthesis, Characterization and Luminescent Properties of Mg- and Cr-Doped Alumina Ceramics

The reported study was funded by RFBR according to the research project No 18-33-00085

Transcriptome profile of yeast reveals the essential role of PMA2 and uncharacterized gene YBR056W-A (MNC1) in adaptation to toxic manganese concentration

© The Royal Society of Chemistry.Adaptation of S. cerevisiae to toxic concentrations of manganese provides a physiological model of heavy metal homeostasis. Transcriptome analysis of adapted yeast cells reveals upregulation of cell wall and plasma membrane proteins including membrane transporters. The gene expression in adapted cells differs from that of cells under short-term toxic metal stress. Among the most significantly upregulated genes are PMA2, encoding an ortholog of Pma1 H+-ATPase of the plasma membrane, and YBR056W-A, encoding a putative membrane protein Mnc1 that belongs to the CYSTM family and presumably chelates manganese at the cell surface. We demonstrate that these genes are essential for the adaptation to toxic manganese concentration and propose an extended scheme of manganese detoxification in yeast

Quantum flutter of supersonic particles in one-dimensional quantum liquids

The non-equilibrium dynamics of strongly correlated many-body systems exhibits some of the most puzzling phenomena and challenging problems in condensed matter physics. Here we report on essentially exact results on the time evolution of an impurity injected at a finite velocity into a one-dimensional quantum liquid. We provide the first quantitative study of the formation of the correlation hole around a particle in a strongly coupled many-body quantum system, and find that the resulting correlated state does not come to a complete stop but reaches a steady state which propagates at a finite velocity. We also uncover a novel physical phenomenon when the impurity is injected at supersonic velocities: the correlation hole undergoes long-lived coherent oscillations around the impurity, an effect we call quantum flutter. We provide a detailed understanding and an intuitive physical picture of these intriguing discoveries, and propose an experimental setup where this physics can be realized and probed directly.Comment: 13 pages, 9 figure

Low-temperature crossover in the momentum distribution of cold atomic gases in one dimension

The momentum distribution function for the two-component 1D gases of bosons and fermions is studied in the limit of strong interatomic repulsion. A pronounced reconstruction of the distribution is found at a temperature much smaller than the Fermi temperature. This new temperature scale, which equals the Fermi temperature divided by the dimensionless coupling strength, is a feature of the two-component model and does not exist in the one-component case. We estimate the parameters relevant for the experimental observation of the crossover effect.Comment: 6 pages, 2 figure

PHASE TRANSFORMATIONS IN ALUMINА CERAMICS WITH IMPURITIES

DTA analysis was performed to determine phase transformations in systems based on an aluminum oxide matrix with chromium, magnesium and manganese impurities. The data of DTA analysis will be used to select the optimum sintering parameters in high-temperature furnaces in vacuum and in air in order to obtain luminescent ceramics.Исследование выполнено при финансовой поддержке РФФИ в рамках научного проекта № 18-33-00085

Synthesis, characterization and luminescent properties of Mg- A nd Cr-doped alumina ceramics

Alumina ceramic doped with Mg and Cr is produced at high-temperature sintering under vacuum at varying annealing temperature and dopant concentration. A differential thermal analysis, X-ray fluorescence, and X-ray diffraction methods are used for sample characterization. The effect of the characteristics described above on the formation of different defects and luminescence centers in the samples was studied with a thermoluminescence method. An increase in the dopant concentration leads to an increase in the pulsed cathodoluminescence intensity of the dopant center in Mg-doped alumina ceramics and a decrease in Cr-doped alumina ceramics. The thermoluminescence intensity for Al2O3:Mg ceramics increases with magnesium concentration growth. The highest thermoluminescence intensity under a pulsed electron beam was obtained for ceramics with chromium (0.1 wt. %) annealed under vacuum at the temperature of 1500 °C for 2 hours. On thermoluminescence curves, one isolated peak at a temperature in the range of 645-665K was registered. © 2020 Author(s).The reported study was funded by RFBR according to the research project No 18-33-00085