Efficiency analysis of state support measures for the small and medium-sized business sector in Russia during the pandemic

A comprehensive analysis of legal and economic measures aimed at state support for small and medium-sized businesses during the COVID-19 pandemic is presented, as well as the relevant regulatory legal acts regulating certain aspects of credit anti-crisis support are studied in detail. Conclusions are presented on the state of the small and medium-sized business sector based on statistical data during the crisis period, and specific negative trends associated with the impact of the pandemic are highlighted. The emphasis is made on a detailed study of foreign experience in the field of anti-crisis measures to support small and medium-sized businesses. Within the framework of the article, such scientific research methods as analysis and generalization were used. It was noted, on the one hand, the high efficiency of anti-crisis support programs, on the other, its problems, including limited and insufficient budget funding

Magnetotransport properties of InSb-MnSb nanostructured films

Hybrid nanostructured InSb - MnSb films were obtained by the pulsed laser deposition using the mechanical droplet separation. Films structure was characterized by different methods (electron diffraction, scanning electron microscopy, atomic and magnetic force microscopy

Luminescence in anion-deficient hafnia nanotubes

Hafnia-based nanostructures and other high-k dielectrics are promising wide-gap materials for developing new opto- and nanoelectronics devices. They possess a unique combination of physical and chemical properties such as insensitivity to electrical and optical degradation, radiation damage stability, a high specific surface area, and an increased concentration of the appropriate active electron-hole centers. The present paper aims to investigate the structural, optical, and luminescent properties of anodized non-stoichiometric $HfO_2$ nanotubes. As-grown amorphous hafnia nanotubes and nanotubes annealed at 700{\deg}C with a monoclinic crystal lattice served as samples. It has been shown that the bandgap $E_g$ for direct allowed transitions amounts to $5.65\pm0.05$ eV for amorphous and $5.51\pm0.05$ eV for monoclinic nanotubes. For the first time, we have studied the features of the intrinsic cathodoluminescence and photoluminescence of the obtained nanotubular $HfO_2$ structures with an atomic deficiency in the anion sublattice at temperatures of 10 and 300 K. A broad emission band with a maximum of 2.3-2.4 eV has been revealed. We have also conducted an analysis of the kinetic dependencies of the observed photoluminescence for synthesized $HfO_2$ samples in the millisecond range at room temperature. It showed that there are several types of optically active capture and emission centers based on vacancy states in the $O_{3f}$ and $O_{4f}$ positions with different coordination numbers and a varied number of localized charge carriers ($V^0$, $V^-$, and $V^{2-}$). The uncovered regularities can be used to optimize the functional characteristics of developed-surface luminescent media based on nanotubular and nanoporous modifications of hafnia.Comment: 15 pages, 6 figures, 3 tables, 50 reference

IMPURITY LUMINESCENCE CENTERS IN FLUORAPATITE FROM QUARTZ-BEARING PARAGENESIS ACCORDING TO PHOTO-, CATHODE- AND SYNCHROTRON-INDUCED LUMINESCENCE

Apatite is typically characterized by a wide variety of spectrum and kinetic characteristics of luminescence; luminescent images of grains are often zonal. A variety of conditions for the formation of the mineral in various types of associations and in many types of host rocks contributes to the occurrence of impurities of various luminogen ions in its structure. The variety of luminescence is associated with impurities of d-metals, REE, different types of anions, as well as with the effects of co-activation in various combinations. The paper presents the results of a comparative study of photo-, cathode- and synchrotron luminescence of apatite (by the example of samples from crystal-bearing deposits of the Neroi region, Subpolar Urals). Using a Jeol JSM6390LV SEM equipped with a Horiba H-CLUE iHR500 attachment, cathodoluminescence spectra of apatite were obtained in the 200–800 nm range. The spectra and kinetic characteristics of apatite luminescence upon excitation by synchrotron radiation at 10 and 300 K have been analyzed for the first time; the physical nature of the excitation bands of the three main luminescence centers Ce3+, Eu2+ and Mn2+ has been examined; it is shown that the luminescence excitation with the energy transfer can be carried out in processes initially initiated by interband transitions or photoionization. The data obtained are important for expanding the possibilities of mineral cathodoluminescence with spatial and spectral resolution and its use in applied problems

IMPURITY LUMINESCENCE CENTERS IN FLUORAPATITE FROM QUARTZ-BEARING PARAGENESIS ACCORDING TO PHOTO-, CATHODE- AND SYNCHROTRON-INDUCED LUMINESCENCE

Apatite is typically characterized by a wide variety of spectrum and kinetic characteristics of luminescence; luminescent images of grains are often zonal. A variety of conditions for the formation of the mineral in various types of associations and in many types of host rocks contributes to the occurrence of impurities of various luminogen ions in its structure. The variety of luminescence is associated with impurities of d-metals, REE, different types of anions, as well as with the effects of co-activation in various combinations. The paper presents the results of a comparative study of photo-, cathode- and synchrotron luminescence of apatite (by the example of samples from crystal-bearing deposits of the Neroi region, Subpolar Urals). Using a Jeol JSM6390LV SEM equipped with a Horiba H-CLUE iHR500 attachment, cathodoluminescence spectra of apatite were obtained in the 200-800 nm range. The spectra and kinetic characteristics of apatite luminescence upon excitation by synchrotron radiation at 10 and 300 K have been analyzed for the first time; the physical nature of the excitation bands of the three main luminescence centers Ce3+, Eu2+ and Mn2+ has been examined; it is shown that the luminescence excitation with the energy transfer can be carried out in processes initially initiated by interband transitions or photoionization. The data obtained are important for expanding the possibilities of mineral cathodoluminescence with spatial and spectral resolution and its use in applied problems. © 2022 Institute of the Earth's Crust. All rights reserved.AAAA-A18-118053090045-8; Russian Foundation for Basic Research, РФФИ: 20-05-00403; Ministry of Education and Science of the Russian Federation, Minobrnauka: -2021-680FUNDING: The study was carried out at the 㘀਀eoanalitik 㘀 Shared Research Facilities of the I?? UB RAS with the 퀀inancial support of the state assignment of IGG UB RAS (AAAA-A18-118053090045-8) and the RFBR grant (20-05-00403). The re-equipment and comprehensive development of the "Geoanalitik" Shared Research Facilities of the IGG UB RAS are 퀀inancially supported by the Ministry of Science and Higher Education of the Russian Federation (Agreement 爃礃?猃?-2021-680)

CATHODOLUMINESCENCE AND RAMAN SPECTROSCOPY AS A BASIS FOR THE SELECTION OF REFERENCE SAMPLES FOR LA-ICP-MS ANALYSIS OF ZIRCON

In order to develop express methods for the quantitative assessment of properties and the selection of reference samples close to investigated sample, to ensure similar conditions for the evaporation of substances and parameters of fractionation of trace elements in LA-ICP-MS, a comparative analysis of the U-Pb isotopic composition, Raman and cathodoluminescent spectra of zircon GJ-1, Plesovice, 91500, Temora-2, Mud Tank reference samples has been performed. Variations in the position and width of the full width at half maximum (FWHM) mode of asymmetric stretching vibrations ν3(SiO4) B1g, as well as the values of the accumulated autoradiation dose Dα and the equivalent dose Dαed have been analyzed. It has been shown that in the series Mud Tank→91500→Temora-2→GJ-1→Plesovice, an increase in the degree of autoradiation damage is recorded: the first three samples are slightly damaged; Plesovice is a moderately damaged difference. The analyzed reference samples can be correctly used for LA-ICP-MS analysis of samples of weakly damaged zircons from magmatites, as well as fragments (zones) of zircon grains from metamorphic rocks of weak and medium degree of structural damage. For the first time, using a Jeol JSM6390LV SEM equipped with a Horiba H-CLUE iHR500 attachment, cathodoluminescence spectra of zircon reference samples were obtained in the 200–800 nm range. It has been found that the integral luminescence brightness varies for samples by more than an order of magnitude; the spectra are of a complex superposition nature; their decomposition into elementary components is ambiguous; a large number of components is detected, which are combined into three main Аi–Вi–Сi groups of broad bands in the near-ultraviolet (UV), blue-green and yellow regions with Emax=4.3–5.0, 2.6–3.5, and 2.1–2.3 eV, respectively. For the first time, it wasproposed to use a triple Аi–Вi–Сi diagram to discriminate zircons by their luminescent properties. It has been found that the position of zircon standards on it significantly differs, which is proposed to be used as a basis for an express assessment of their properties and selection. A comparative analysis was performed on the U-Pb isotopic composition, discordance of age determinations, features of Raman and cathodoluminescence spectra for a large sample of accessory zircon from kimberlites and diamond-bearing placers of Yakutia, as well as metamorphic rocks of the Urals – from granite of the final phase of the Neplyuevsky pluton, high-magnesian diorite massif, from high-pressure garnetites of the Mindyaksky lherzolite massif, from leptinites of the Taldyk block Mugodzhar. The Аi–Вi–Сi diagram is compared with similar data on the cathodoluminescence of the reference samples

Luminescence in Anion-Deficient Hafnia Nanotubes

Hafnia-based nanostructures and other high-k dielectrics are promising wide-gap materials for developing new opto- and nanoelectronic devices. They possess a unique combination of physical and chemical properties, such as insensitivity to electrical and optical degradation, radiation damage stability, a high specific surface area, and an increased concentration of the appropriate active electron-hole centers. The present paper aims to investigate the structural, optical, and luminescent properties of anodized non-stoichiometric HfO2 nanotubes. As-grown amorphous hafnia nanotubes and nanotubes annealed at 700 °C with a monoclinic crystal lattice served as samples. It has been shown that the bandgap Eg for direct allowed transitions amounts to 5.65 ± 0.05 eV for amorphous and 5.51 ± 0.05 eV for monoclinic nanotubes. For the first time, we have studied the features of intrinsic cathodoluminescence and photoluminescence in the obtained nanotubular HfO2 structures with an atomic deficiency in the anion sublattice at temperatures of 10 and 300 K. A broad emission band with a maximum of 2.3–2.4 eV has been revealed. We have also conducted an analysis of the kinetic dependencies of the observed photoluminescence for synthesized HfO2 samples in the millisecond range at room temperature. It showed that there are several types of optically active capture and emission centers based on vacancy states in the O3f and O4f positions with different coordination numbers and a varied number of localized charge carriers (V0, V−, and V2−). The uncovered regularities can be used to optimize the functional characteristics of developed-surface luminescent media based on nanotubular and nanoporous modifications of hafnia. © 2023 by the authors.Russian Science Foundation, RSF: 23-22-00310This work was supported by the Russian Science Foundation under grant no. 23-22-00310, https://rscf.ru/en/project/23-22-00310/ (accessed on 1 November 2023)

ПРИМЕСНЫЕ ЦЕНТРЫ СВЕЧЕНИЯ ВО ФТОРАПАТИТЕ ИЗ ХРУСТАЛЕНОСНОГО ПАРАГЕНЕЗИСА ПО ДАННЫМ ФОТО-, КАТОДО- И СИНХРОТРОННО-ИНДУЦИРОВАННОЙ ЛЮМИНЕСЦЕНЦИИ

Apatite is typically characterized by a wide variety of spectrum and kinetic characteristics of luminescence; luminescent images of grains are often zonal. A variety of conditions for the formation of the mineral in various types of associations and in many types of host rocks contributes to the occurrence of impurities of various luminogen ions in its structure. The variety of luminescence is associated with impurities of d-metals, REE, different types of anions, as well as with the effects of co-activation in various combinations. The paper presents the results of a comparative study of photo-, cathode- and synchrotron luminescence of apatite (by the example of samples from crystal-bearing deposits of the Neroi region, Subpolar Urals). Using a Jeol JSM6390LV SEM equipped with a Horiba H-CLUE iHR500 attachment, cathodoluminescence spectra of apatite were obtained in the 200–800 nm range. The spectra and kinetic characteristics of apatite luminescence upon excitation by synchrotron radiation at 10 and 300 K have been analyzed for the first time; the physical nature of the excitation bands of the three main luminescence centers Ce3+, Eu2+ and Mn2+ has been examined; it is shown that the luminescence excitation with the energy transfer can be carried out in processes initially initiated by interband transitions or photoionization. The data obtained are important for expanding the possibilities of mineral cathodoluminescence with spatial and spectral resolution and its use in applied problems.Для минерала апатита типично широкое разнообразие спектра и кинетических характеристик люминесценции; люминесцентные изображения зерен часто зональны. Разнообразие условий формирования минерала в разных типах ассоциаций и вмещающих пород способствует появлению в его структуре примесей различных ионов-люминогенов. Разнообразие люминесценции связано с примесями d-металлов, РЗЭ, разных типов анионов, а также с эффектами соактивации в различных комбинациях. В работе представлены результаты сравнительного исследования фото-, катодо- и синхротронной люминесценции фторапатита (на примере проб из хрусталеносных месторождений Неройского района, Приполярный Урал). С использованием СЭМ Jeol JSM6390LV, оборудованного приставкой Horiba H-CLUE iHR500, получены спектры катодолюминесценции фторапатита в диапазоне 200–800 нм. Впервые проанализированы спектры и кинетические характеристики люминесценции фторапатита при возбуждении синхротронным излучением вакуумного ультрафиолетового диапазона при 10 и 300 К; рассмотрена физическая природа полос возбуждения трех основных центров свечения Ce3+, Eu2+ и Mn2+; показано, что возбуждение люминесценции с передачей энергии может осуществляться в процессах, первоначально инициированных межзонными переходами или фотоионизацией. Полученные данные важны для расширения возможностей катодолюминесцентной спектроскопии зерен минерала с пространственным и спектральным разрешением и использования ее в решении прикладных минералого-геохимических задач

КАТОДОЛЮМИНЕСЦЕНЦИЯ И СПЕКТРОСКОПИЯ КОМБИНАЦИОННОГО РАССЕЯНИЯ СВЕТА КАК ОСНОВА ДЛЯ ВЫБОРА РЕФЕРЕНСНЫХ ОБРАЗЦОВ ПРИ ЛА-ИСП-МС-АНАЛИЗЕ ЦИРКОНА

In order to develop express methods for the quantitative assessment of properties and the selection of reference samples close to investigated sample, to ensure similar conditions for the evaporation of substances and parameters of fractionation of trace elements in LA-ICP-MS, a comparative analysis of the U-Pb isotopic composition, Raman and cathodoluminescent spectra of zircon GJ-1, Plesovice, 91500, Temora-2, Mud Tank reference samples has been performed. Variations in the position and width of the full width at half maximum (FWHM) mode of asymmetric stretching vibrations ν3(SiO4) B1g, as well as the values of the accumulated autoradiation dose Dα and the equivalent dose Dαed have been analyzed. It has been shown that in the series Mud Tank→91500→Temora-2→GJ-1→Plesovice, an increase in the degree of autoradiation damage is recorded: the first three samples are slightly damaged; Plesovice is a moderately damaged difference. The analyzed reference samples can be correctly used for LA-ICP-MS analysis of samples of weakly damaged zircons from magmatites, as well as fragments (zones) of zircon grains from metamorphic rocks of weak and medium degree of structural damage. For the first time, using a Jeol JSM6390LV SEM equipped with a Horiba H-CLUE iHR500 attachment, cathodoluminescence spectra of zircon reference samples were obtained in the 200–800 nm range. It has been found that the integral luminescence brightness varies for samples by more than an order of magnitude; the spectra are of a complex superposition nature; their decomposition into elementary components is ambiguous; a large number of components is detected, which are combined into three main Аi–Вi–Сi groups of broad bands in the near-ultraviolet (UV), blue-green and yellow regions with Emax=4.3–5.0, 2.6–3.5, and 2.1–2.3 eV, respectively. For the first time, it wasproposed to use a triple Аi–Вi–Сi diagram to discriminate zircons by their luminescent properties. It has been found that the position of zircon standards on it significantly differs, which is proposed to be used as a basis for an express assessment of their properties and selection. A comparative analysis was performed on the U-Pb isotopic composition, discordance of age determinations, features of Raman and cathodoluminescence spectra for a large sample of accessory zircon from kimberlites and diamond-bearing placers of Yakutia, as well as metamorphic rocks of the Urals – from granite of the final phase of the Neplyuevsky pluton, high-magnesian diorite massif, from high-pressure garnetites of the Mindyaksky lherzolite massif, from leptinites of the Taldyk block Mugodzhar. The Аi–Вi–Сi diagram is compared with similar data on the cathodoluminescence of the reference samples. С целью разработки экспресс-методов количественной оценки свойств и выбора референсных образцов, близких к исследуемому, для обеспечения схожих условий испарения вещества и параметров фракционирования микроэлементов при ЛА-ИСП-МС, выполнен сравнительный анализ данных по U-Pb-изотопному составу, особенностям спектров комбинационного рассеяния света и катодолюминесценции международных референсных образцов циркона GJ-1, Plesovice, 91500, Temora-2, Mud Tank. Проанализированы вариации положения и значений ширины на половине высоты (FWHM) моды асимметричных валентных колебаний ν3(SiO4) B1g, а также значений накопленной авторадиационной дозы Dα и эквивалентной дозы Dαэк. Показано, что в ряду Mud Tank→91500→Temora-2→GJ-1→Plesovice фиксируется рост степени авторадиацинного повреждения: первые три образца – слабоповрежденные, Plesovice – среднеповрежденная разность. Проанализированные стандарты могут быть корректно использованы при ЛА-ИСП-МС-анализе проб слабоповрежденных цирконов магматитов, а также фрагментов (зон) зерен цирконов метаморфитов слабой и средней степени повреждения структуры. Впервые с использованием СЭМ Jeol JSM6390LV, оборудованного приставкой Horiba H-CLUE iHR500, получены спектры катодолюминесценции референсных образцов циркона в диапазоне 200–800 нм с локальностью до 1 мкм. Установлено, что интегральная яркость свечения варьируется по пробам более чем на порядок; спектры носят сложный суперпозиционный характер; их разложение на элементарные составляющие неоднозначно; выделяется большое число составляющих, которые объединены в три основные Аi–Вi–Сi группы широких полос в ближней ультрафиолетовой (УФ), сине-зеленой и желтой областях с Eмакс=4.3–5.0, 2.6–3.5 и 2.1–2.3 эВ соответственно. Впервые предложено использовать тройную Аi–Вi–Сi диаграмму для дискриминации цирконов по люминесцентным свойствам; установлено, что положение стандартов цирконов на ней значимо различается, что предлагается использовать как основу для экспресс-оценки их свойств и выбора. Выполнен сравнительный анализ результатов по U-Pb-изотопному составу, дискордантности возрастных определений, особенностям спектров комбинационного рассеяния света и катодолюминесценции для большой выборки проб акцессорного циркона из кимберлитов и алмазоносных россыпей Якутии, а также метаморфических и магматических пород Урала – из гранита заключительной фазы Неплюевского плутона, высокомагнезиального диорита Челябинского массива, из высокобарических гранатитов Миндякского лерцолитового массива, из лептинитов Талдыкского блока Мугоджар. На Аi–Вi–Сi диаграмме выполнено сопоставление с аналогичными данными по катодолюминесценции референсных образцов циркона

Low-frequency acoustic propagation loss in the Arctic Ocean: results of the Arctic climate observations using underwater sound experiment

Acoustic data from the Arctic climate observations using underwater sound (ACOUS) experiment are analyzed to determine the correlation between acoustic propagation loss and the seasonal variability of sea ice thickness. The objective of this research is to provide long-term synoptic monitoring of sea ice thickness, an important global climate variable, using acoustic remote sensing. As part of the ACOUS program an autonomous acoustic source deployed northwest of Franz Josef Land transmitted tomographic signals at 20.5 Hz once every four days from October 1998 until December 1999. These signals were received on a vertical array in the Lincoln Sea 1250 km away. Two of the signals transmitted in April 1999 were received on a vertical array at ice camp APLIS in the Chukchi Sea north of Point Barrow, Alaska, at a distance of approximately 2720 km from the source. Temporal variations of the modal propagation loss are examined. The influence of ice parameters, variations of the sound speed profile, and mode-coupling effects on the propagation losses of individual modes is studied. The experimental results are compared to the results of the earlier experiments and the theoretical prediction using numerical modeling