On the spatial structure of the Perseids meteor stream

The analysis of radar observations of the Perseid meteor stream conducted in an ionospherical laboratory in the period from 1964 to 1981 is presented. The Perseids meteor rates were determined by the fluctuation method. Analysis of their hourly distributions showed that the stream maximum position is different for different years, i.e., the stream nodal position is constantly changing. The results of the analysis are presented and discussed

Effect of anion doping on mobility of ionic charge carriers in solid solutions based on Ba2In2O5

In the work, mobilities of oxygen and protons are determined for F --substituted solid solutions based on brownmillerite Ba 2In2O5 and their concentration dependences are analyzed. It is found that small additives of the more mobile anion (F - ions) promote an increase in oxygen mobility as a result of additional effects of repulsion of ions of different nature in the anion sublattice. Mobility of oxygen at high fluoride concentrations decreases due to the overlapping of migration paths of diffusion, as both anions, fluoride ions and oxygen ions, move via oxygen vacancies. Concentration dependences of mobility of proton carriers have a similar character, which is related to the effect of the oxygen sublattice. The anion doping method used in the work can be recommended as the general method for improvement of the transport characteristics of oxygen-ionic and protonic conductors with a perovskite-like structure. © 2013 Pleiades Publishing, Ltd

Electric properties of oxyfluorides Ba2In2O 5-0.5x F x with brownmillerite structure

Synthesis of fluoro-substituted substances based on brownmillerite Ba 2In2O5 is carried out. The width of the homogeneity region of the Ba2In2O5-0.5x F x (0 < x ≤ 0.25) solid solution was established using X-ray analysis. Measurement of temperature dependences of conductivity in atmospheres with different partial pressure of water vapor (pH2O = 3.3 and 2 Ч 103 Pa) showed an increase in conductivity at T ≤ 550 C in a humid atmosphere, which is due to appearance of proton transport. The dependence of conductivity on partial oxygen pressure (pO2 = 0.21 Ч 105 to 10-15 Pa) is studied in the temperature range of 500-1000 C; ion transport numbers are calculated. The method of polarization measurements was used to determine transport numbers of fluoride. Total conductivity is divided into ion (proton, oxygen, and fluoride ion) and electron components. Analysis of concentration dependences of conductivities showed that low concentrations of fluoride allow increasing both the total and partial conductivities (oxygen-ion and proton) and, besides, allow shifting the "order-disorder" phase transition by 100 C to the low temperature range. © 2013 Pleiades Publishing, Ltd

Materials AIILnInO4 with Ruddlesden-Popper Structure for Electrochemical Applications: Relationship between Ion (oxygen-ion, proton) Conductivity, Water Uptake, and Structural Changes

In this paper, the review of the new class of ionic conductors was made. For the last several years, the layered perovskites with Ruddlesden-Popper structure AIILnInO4 attracted attention from the point of view of possibility of the realization of ionic transport. The materials based on Ba(Sr)La(Nd)InO4 and the various doped compositions were investigated as oxygen-ion and proton conductors. It was found that doped and undoped layered perovskites BaNdInO4, SrLaInO4, and BaLaInO4 demonstrate mixed hole-ionic nature of conductivity in dry air. Acceptor and donor doping leads to a significant increase (up to ~1.5–2 orders of magnitude) of conductivity. One of the most conductive compositions BaNd0.9Ca0.1InO3.95 demonstrates the conductivity value of 5∙10−4 S/cm at 500 °C under dry air. The proton conductivity is realized under humid air at low (<500 °C) temperatures. The highest values of proton conductivity are attributed to the compositions BaNd0.9Ca0.1InO3.95 and Ba1.1La0.9InO3.95 (7.6∙10−6 and 3.2∙10−6 S/cm correspondingly at the 350 °C under wet air). The proton concentration is not correlated with the concentration of oxygen defects in the structure and it increases with an increase in the unit cell volume. The highest proton conductivity (with 95−98% of proton transport below 400 °C) for the materials based on BaLaInO4 was demonstrated by the compositions with dopant content no more that 0.1 mol. The layered perov-skites AIILnInO4 are novel and prospective class of functional materials which can be used in the different electrochemical devices in the near future. © 2021 by the authors. Licensee MDPI, Basel, Switzerland.This article was financially supported by the Ministry of Education and Science of the Russian Federation (state assignment no. 075-03-2021-051/5)

Fluorine and chlorine doping in oxygen-deficient perovskites: A strategy for improving chemical stability

The present work describes the effect of fluorine and chlorine doping on the chemical stability of proton conductors Ba2In2O5, Ba4In2Zr2O11, and Ba4Ca2Nb2O11 against carbon dioxide and water steam. It was proved that both undoped and halide-doped compositions demonstrate good chemical stability under H2O treatment without degradation and without any hydrolytic decomposition. The hydration process leads to the change in the crystal structure only. The treatment in the CO2/air (1:1) atmosphere (500 °C, 10 h) leads to the decomposition of undoped samples only. Halide-doped samples retain their structure without detectable products, that is, they are more chemically stable compared with undoped compositions. The method of halide doping can be used as the promising technique for obtaining the new perovskite-related materials with high level of chemical stability. © 2019 Académie des sciencesRussian Science Foundation, RSF: 18-73-00006This work was financially supported by the Russian Science Foundation (project 18-73-00006 )

New and rare lichens and allied fungi from Arkhangelsk Region, North-West Russia. II

Information about 38 species of lichens is presented. In total, 18 species are newly recorded for Arkhangelsk Region, 11 species are new for its mainland area. New localities for 9 rare species are presented. Thalloidima physaroides is new for the territory of Northwest Russia. The species Sclerophora peronella is reported for the second time in the whole territory of Russia, Calicium pinicola – in European Russia and Rhizocarpon simillimum – in Northwest Russia. For Vezdaea rheocarpa and Pilophorus robustus the westernmost localities in Russia are reported. The new localities of 9 species included in the Red Data Book of Arkhangelsk Region are presented. Six species are added to the list of lichens of Vodlozersky National Park

The Effect of Simultaneous Homo- and Heterogeneous Doping on Transport Properties of Ba2In2O5

In this article, the possibility of application of simultaneous homogeneous and heterogeneous doping has been described for the first time. The composite 0.7Ba1.95In2O4.9F0.1⋅0.3Ba2 InNbO6 has been obtained by in situ solid-state method. The scanning electron microscopy and thermogravimetry investigations have beencarried out; the electrical properties have been examined. It has been proved that simultaneous homogeneous and heterogeneous doping is a prospective method for obtaining high-conductive proton electrolytes. Keywords: brownmillerite, composite, anionic doping, fluorin

The lichens of forest rocky communities of the hill Muroigora (Arkhangelsk Region, Northwest Russia)

The present study reports 188 species and 2 subspecies of lichens and allied fungi from forest rocky communities of the hill Muroigora situated in the Arkhangelsk part of the National park “Vodlozersky” (Arkhangelsk Region, NW Russia). Lepraria ecorticata is new to Russia, and 13 more species are new for the mainland area of the Arkhangelsk Region: Arthonia mediella, Arthonia vinosa, Bacidia igniarii, Bryoria vrangiana, Chaenothecopsis pusiola, Cladonia caespiticia, Lecidea plana, Lepraria borealis, Micarea misella, Pertusaria pustulata, Schaereria cinereorufa, Xanthoparmelia pulla and Xylographa trunciseda. Two lichen species, Bryoria fremontii and Lobaria pulmonaria, are in the Red Data Books of the Arkhangelsk Region and Russian Federation. A total of 89 species are reported as new for the Vodlozersky National Park.

Optical and photoelectron spectroscopy studies of KPb2Cl 5 and RbPb2Cl5 laser crystals

The paper presents the results of experimental study of electronic structure of RbPb2Cl5 and KPb2Cl5 laser crystals performed by the optical and photoelectron spectroscopy methods. On the basis of the optical absorption and low-temperature reflection spectra of these crystals we have determined the energy positions of the edges of the low-energy tail of the host absorption, the positions of the first excitonic absorption peaks, and exciton binding energies. The bandgap widths of these crystals at 8 K were estimated as Eg = 4.83 and 4.79 eV, respectively. Qualitative and quantitative analysis of RbPb2Cl 5 and KPb2Cl5 crystals were made on the basis of the core states photoelectron spectra. The elemental composition of the (0 0 1) surfaces of the crystals, the chemical state of the host atoms, the electronic structure of the valence band of the crystals were discussed on the basis on the spectroscopic data. © 2012 Elsevier B.V. All rights reserved

ANALYSIS OF THE DIGITAL TRANSFORMATION OF GENERAL EDUCATION

Digital transformation of the society, boosted by the COVID-19 pandemic, has determined new processes in the socio-economic sphere. Foreign and domestic researchers are unanimous in their opinion that digitalization is the main trend of global development, and the need for digital transformation of education is preconditioned by organizational, technological, managerial, economic, and other changes taking place in various spheres of society, economy and production. Object of the study: the digital transformation process. Subject: general education. Goal: to identify the essence and characteristics of the implementation of digital transformation processes in general education. Objectives: to analyze the essence and semantic understanding of the "digital transformation" category; to describe the types and structure of the main processes of digital transformation in general education. Methods: methodological approaches: systemic approach; research methods: theoretical (analysis of information sources; comparative study; content analysis; generalization, systematization). Conclusions: there is no unity in the scientific attribution of the concepts of "digitalization of education", "digital transformation of education"; analysis of the prospects of digital transformation of general education indicates that its main positive effects may be as follows: ensuring equality of educational opportunities and continuity of education; updating the goals and content of education; optimizing forms, methods, teaching and methodological support of the educational process and the students’ learning and cognitive activities; creating conditions for personalized learning; increasing the effectiveness of quality control and monitoring; reducing the amount of routine work for management and teaching staff, etc.; based on the analysis of scientific research, the problem of information security of electronic educational resources used in general education has been identified; an analysis of the current situation on the software market is presented, and general recommendations on the protection of data recorded in electronic educational resources are give