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The first records of Heterolocha laminaria (Herrich-Schäffer, 1852) (Lepidoptera: Geometridae) in Ukraine are presented. Until the recent past, the European registrations of H. laminaria had been only reported from Rostov Region of Russia. New records were made at several localities within Dnipropetrovsk, Zaporizhzhia, Odesa and Poltava regions, in Southern, South-Western, South-Eastern and Central Ukraine. These findings were revealed from mid-June to mid-August in various habitat types: steppes, artificial deciduous and mixed forests, agrocenosis. The current records significantly shift westward the range limits of H. la­mi­na­ria. Thus, a newly-discovered locality in Savran Forest is the westernmost point in the entire species range. Most likely the westward expansion of this species has occurred in recent decades. The habitats, adults, and male genitalia of H. laminaria are illustrated.

A prototype of the electromagnetic calorimeter for the GAMMA-400 γ-ray telescope has been calibrated at the Pakhra S-25R electron synchrotron of the Lebedev Physical Institute. The measured energy resolution of the GAMMA-400 calorimeter is consistent with the results of the Monte Carlo simulation. The applicability of the Pakhra S-25R accelerator for calibrating detectors in various experiments has been confirmed.

Clustering of the regions of the Siberian Federal District (SFD) was carried out according to the state of reproduction of labor resources in rural areas. The modern problems of reproduction of labor resources in the regions of the SFD are identified, taking into account the peculiarities of each of them. As a result, the distribution of the regions of the Siberian Federal District by the state of labor resources of the rural territories was obtained by the following clusters: national, raw materials and leaders. Recommendations for the development of the reproduction of labor resources in rural areas are offered.

In order to study the isotopic effects in semiconductor materials, single crystals of high chemical and isotopic purity are required. The reliability of the obtained data on the magnitude and the direction of isotopic shifts depends on the accuracy of determining the concentration of all stable isotopes. In the isotopic analysis of enriched “silicon-28” with a high degree of enrichment ( 99.99%), it is necessary to determine the impurities of 29Si and 30Si isotopes at the level of 10-3 ¸ 10-5 at. %. At this concentration level, these isotopes can be considered as impurities. It is difficult to achieve high measurement accuracy with simultaneous registration of the main and “impurity” isotopes in such a wide range of concentrations. The registration of analytical signals of silicon isotopes must be carried out in the solutions with different matrix concentrations. The use of the solutions with the high concentration of the matrix element requires the introduction of corrections for matrix noise and the drift of the instrument sensitivity during the measurement. It is possible to reduce the influence of the irreversible non-spectral interference and sensitivity drift by using the method of internal standardization. The inconsistency of the literature data on the selection criteria for the internal standard required studying the behavior of the signals of the “candidates for the internal standard” for the ELEMENT 2 single-collector high-resolution inductively coupled plasma mass spectrometer on the matrix element concentration and the nature of the solvent, as well as on the solution nebulizing time. Accounting for the irreversible non-spectral matrix noise and instrumental drift in isotopic analysis of enriched “silicon-28” and initial 28SiF4 by inductively coupled plasma mass spectrometry had allowed us to reduce by 3-5 times the random component and by more than an order of magnitude the systematic component of the measurement error in comparison with the external standard method. This made it possible to carry out, with sufficient accuracy, the operational control of the isotopic composition of enriched “silicon-28”, both in the form of silicon tetrafluoride and polycrystalline silicon obtained from it, using a single serial device in the range of isotopic concentrations 0.0001–99.999%.Key words: high-resolution inductively coupled plasma mass spectrometry, isotope analysis, isotopically enriched silicon, internal standard DOI: http://dx.doi.org/10.15826/analitika.2021.25.2.009P.A. Otopkova, A.M. Potapov, A.I. Suchkov, A.D. Bulanov, A.Yu. Lashkov G.G. Devyatykh Institute of Chemistry of High-Purity Substances of the Russian Academy of Sciences (IChHPS RAS), 49 Tropinina St., Nizhny Novgorod, 603951, Russian Federation, Для изучения изотопических эффектов в полупроводниковых материалах требуются монокристаллы с высокой химической и изотопной чистотой. Надежность полученных данных о величине и направлении изотопических сдвигов зависит от точности определения концентрации всех стабильных изотопов. При изотопном анализе обогащенного “кремния-28” с высокой степенью обогащения (более 99.99 %) необходимо определять примеси изотопов 29Si и 30Si на уровне 10-3 ¸ 10-5 ат. %. На таком уровне концентраций указанные изотопы можно рассматривать как примеси. Достижение высокой точности измерений при одновременной регистрации основного и “примесных” изотопов в таком широком интервале концентраций затруднительно. Регистрацию аналитических сигналов изотопов кремния приходится проводить на растворах с разной концентрацией матрицы. Использование растворов с высокой концентрацией матричного элемента требует введения поправок на матричные помехи и дрейф чувствительности прибора в процессе измерения. Снизить влияние необратимых неспектральных помех и дрейфа чувствительности можно при использовании метода внутренней стандартизации. Противоречивость литературных данных о критериях выбора внутреннего стандарта потребовала исследования поведения сигналов элементов “кандидатов во внутренний стандарт“ для одноколлекторного масс-спектрометра высокого разрешения с индуктивно связанной плазмой ELEMENT 2 от концентрации матричного элемента и природы растворителя, а также от времени распыления раствора. Учет необратимых неспектральных матричных помех и аппаратного дрейфа при изотопном анализе обогащенного “кремния-28” и исходного 28SiF4 методом масс-спектрометрии с индуктивно связанной плазмой позволил снизить в 3-5 раз случайную составляющую и более чем на порядок систематическую составляющую погрешности измерения по сравнению с методом внешнего стандарта. Это позволило проводить с достаточной точностью оперативный контроль изотопного состава обогащенного “кремния-28”, как в виде тетрафторида кремния, так и получаемого из него поликристаллического кремния с помощью одного серийного прибора в интервале изотопных концентраций 0.0001–99.999 ат. %.Ключевые слова: масс-спектрометрия высокого разрешения с индуктивно связанной плазмой, изотопный анализ, изотопнообогащенный кремний, внутренний стандартDOI: http://dx.doi.org/10.15826/analitika.2021.25.2.009

The additional data to the list of butterflies and moths of Ichnia National Nature Park is given. There are original records for 91 lepidopterous species from 78 genera of 12 families presented. Actually, 42 species from 37 genera of 10 families are recorded in the Ichnia National Nature Park for the first time. Recently the checklist of Lepidoptera of Ichnia National Nature Park and its immediate environs (taking into account the species from the previously published list) includes 633 known species from 379 genera of 31 families. According to the number of registered species, the following Lepidoptera families prevail in the fauna of Ichnia National Nature Park: Noctuidae (190 species from 99 genera), Geometridae (147 species from 83 genera), Tortricidae (70 species from 35 genera), Erebidae (36 species from 27 genera), Pyralidae (34 species from 25 genera) and Crambidae (24 species from 18 genera). The best studied is the territory of Arboretum ‘Trostianets’ of the National Academy of ciences of Ukraine (as a separate component of Ichnia National Nature Park), where 506 lepidopterous species from 302 genera of 21 families were registered. In other parts of the Ichnia National Nature Park 156 species from 133 genera of 27 families were recorded. It shows a lack of knowledge of its Lepidoptera diversity as a whole.

The results of the participation of the All-Russia Thermal Engineering Institute in the implementation of systems for plasma-assisted startup of and flame stabilization in the boiler of the Cherepet’ TPP are discussed.

Optimization of algorithms for computing the values of polynomials, more precisely, of monomials, is equivalent to the problem of constructing for a given number a minimal additive chain. To search for such chains, no algorithms are known except brute force. The increase in the complexity of the brute force algorithm is very large. Among chains of the same length there are a lot of equivalent ones, that is, those ending with the same number. The article provides a sufficient criterion for the equivalence of chains and shows how the use of the criterion reduces the procedure for the formation of all additive chains of a fixed length.

The GAMMA-400 gamma-ray telescope is planned for the launch at the end of 2026 on the Navigator service platform designed by Lavochkin Association on an elliptical orbit with following initial parameters: an apogee $${\sim}$$ 300 000, a perigee $${\sim}$$ 500 km, a rotation period $${\sim}$$ 7 days and inclination of 51.4 $${}^{\circ}$$ . The apparatus is expected to operate for more than 5 years, reaching an unprecedented sensitivity for the search of dark matter signatures and the study of the unresolved and so far unidentified gamma-ray sources. The segmented anticoincidence counters surround the converter-tracker and calorimeter of the telescope with the purpose of vetoing to assure a clean track reconstruction and charged particle background suppression. The anticoincidence detector prototype based on long BC-408 scintillator with silicon photomultipliers readout was tested using 300-MeV positron beam of synchrotron C-25P ‘‘PAKHRA’’ of Lebedev Physical Institute. The measurement setup, design concepts for the prototype detector together with test results are discussed.

The new records of 94 species of noctuid moths (Noctuoidea) in the North-Western Pryazovia and adjacent regions of the steppe zone of Ukraine are presented. One species Dysgonia rogenhoferi is recorded in Ukraine for the first time. Founds of species Eublemma amasina and Caradrina expansa are the second in our country. One species (Eublemma amasina) in Dnipro Region, 2 (Ptilophora plumigera and Schargacucullia gozmanyi) — in Donetsk Region, 2 (Cerura erminea and Apamea unanimus) — in Odesa Region, 5 (Acantholipes regularis, Dysgonia rogenhoferi, Caradrina expansa, Luperina rubella, and Aporophyla canescens) — in Zaporizhzhya Region, 7 (Clostera anastomosis, Zanclognatha lunalis, Polyphaenis sericata, Protarchanara brevilinea, Aporophyla canescens, Lacanobia praedita, and Dichagyris forcipula) — in Kherson Region, and 10 (Clostera anastomosis, Cucullia argentina, Meganephria bimaculosa, Hoplodrina blanda, Sedina buettneri, Tiliacea aurago, Cosmia diffinis, Cosmia affinis, Aporophyla lutulenta and Xestia trifida) — in Mykolaiv Region are registered for the first time. In addition, new localities of a number of little-known, local and rare species in Ukraine or in its separate regions were discovered.

A procedure is described for determining the isotopic composition of highly enriched silicon as elementary 28Si and initial 28SiF4 by a single collector double focusing sector field ICP MS over a wide range of isotope concentrations (more than 6 orders of magnitude). To expand the range of measured isotopic concentrations, the signals of the main and “impurity” isotopes were recorded in solutions of different concentrations. The determination of the matrix effects and mass discrimination factors was carried out using the isotopic dilution method. This procedure allowed us to reach the uncertainty of measuring the concentration of the main isotope of ten thousandths of a percent in enriching >99.999% on a high-resolution single-collector inductively coupled plasma mass spectrometer.

The GAMMA-400 (Gamma Astronomical Multifunctional Modular Apparatus) will be a new generation satellite gamma-observatory. The gamma-ray telescope GAMMA-400 consists of the anticoincidence system (top and lateral sections—ACtop and AClat), the converter-tracker (C), the time-of-flight system TOF (two sections S1 and S2), the position-sensitive and electromagnetic calorimeters (CC1 and CC2), the scintillation detectors of the calorimeter (S3 and S4) and lateral anticoincidence detectors of the calorimeter LD. Two apertures used for observation of transient events do not require the best angular resolution as for the gamma-ray bursts and solar flares from both upper and lateral directions. Additional aperture allows the particle registering from upper direction, which do not interact with converter-tracker and do not form a TOF signal. The lateral aperture allows registering of γ-quanta in perpendicular direction with respect to main axis of GAMMA-400 due to CC2, LD, S3, and S4. The thickness of CC2 in this direction is ∼44 X0 and this allows detection of gammas, electrons and positrons with energies up to 10 TeV. The results of calculation of the fractal dimension of temporal profiles of additional aperture prototype of GAMMA-400 during its calibration using secondary positron beam of the synchrotron C-25P “PAKHRA” of Lebedev Physical Institute confirm the absence of any correlation between the AC and CC1 characteristics and correspondence of additional aperture background to Poisson statistics or Erlang one with shape parameter up to 10.

The space-based GAMMA-400 gamma-ray telescope will measure the fluxes of gamma rays in the energy range from ∼20 MeV to several TeV and cosmic-ray electrons and positrons in the energy range from several GeV to several TeV to investigate the origin of gamma-ray sources, sources and propagation of the Galactic cosmic rays and signatures of dark matter. The instrument consists of an anticoincidence system, a converter-tracker (thickness one radiation length, 1 X0), a time-of-flight system, an imaging calorimeter (2 X0) with tracker, a top shower scintillator detector, an electromagnetic calorimeter from CsI(Tl) crystals (16 X0) with four lateral scintillation detectors and a bottom shower scintillator detector. In this paper, the capability of the GAMMA-400 gamma-ray telescope for electron and positron measurements is analyzed. The bulk of cosmic rays are protons, whereas the contribution of the leptonic component to the total flux is ∼10−3 at high energy. The special methods for Monte Carlo simulations are proposed to distinguish electrons and positrons from proton background in the GAMMA-400 gamma-ray telescope. The contribution to the proton rejection from each detector system of the instrument is studied separately. The use of the combined information from all detectors allows us to reach a proton rejection of up to ∼1 × 104.

The aim of research was to study morphological characteristics of the osteogenic properties of the natural white Acropora coral skeleton granules when implanted under the skin.Material and methods. The study included 60 sexually mature male Wistar rats. The object of the morphological study was subcutaneous implants isolated for different periods of the experiment. The experimental animals were divided into three groups, 20 animals each. In the 1st and 2nd groups the granules were placed in a gelatin capsule, in the 3rd group – the granules were implanted directly under the skin of the animals. When preparing implants for the 1st group, the granules were treated with the blood of an animal taken from the tail vein during surgery. Implants for the 2nd group of animals were not treated with blood. Histological research methods (hematoxylin and eosin staining according to Mallory, Weigert–Van Gieson, and Masson–Goldner; staining to determine the age of fibrin (BioVitrum)) were used in the study; the results were statistically processed.Results. The results obtained demonstrated that heterotopic bone formation based on granules from the skeleton of natural coral was only possible when they were in wide contact with blood on the first day of the experiment. The results of the study also evidenced that blood clot elements, fibrocytes, and osteoblasts were the source for the development of newly formed bone tissues. The gelatin capsule allowed temporarily restricting coral granules from the surrounding tissues with peripheral venous blood cells inside; the fact contributing to the formation and accumulation of cellular elements and subsequently leading to the formation of young bone tissues.Conclusions. As demonstrated, subcutaneous implantation of coral granules in a gelatin capsule without blood did not result in osteogenesis. Due to the apparent osteoinductive potential, natural coral skeleton granules applied according to the proposed method are considered to be an alternative to other osteoplastic materials for the stimulation of de novo bone formation.

The GAMMA-400 space project is one of the new generation of space observatories designed to search for signs of dark matter in the cosmic gamma emission, and to measure the characteristics of diffuse gamma-ray emission and gamma-rays from the Sun during periods of solar activity; gamma-ray bursts; extended and point gamma-ray sources; and electron, positron, and cosmic-ray nuclei fluxes with energies in the TeV ranges. The GAMMA-400 γ-ray telescope constitutes the core of the scientific instrumentation. The nature of the intended experiments imposes stringent requirements on the gamma telescope’s system of trigger signal formation, now being developed using the state-of-the-art logic devices and fast data links. The design concept of the system is discussed, along with the chosen engineering solutions and some experimental results obtained during the operation of the system prototype using a positron beam with energies of 100–300 MeV from the PAKHRA S-25R synchrotron at the Lebedev Physical Institute.

To estimate possible changes for some economical branches in South Ukraine which use the nature resources, three scenarios of climate changes were reviewed: increase of temperature and increase of precipitation; increase of temperature and decrease of precipitation; decrease of temperature and increase of precipitation. Impact on the Azov Sea ecosystems under these three scenarios was considered in respect of changes in salinity and temperature of water that consequently effects on ichthyofauna and fish industry. Trends of fish suffocation are also described. Agricultural risks induced by pests (on an example of the locust) under extreme high temperatures in a spring-summer season were discussed, with identification of possible distribution sites of the pest. The research carried out in the framework of the project “Building Capacity for a Black Sea Catchment Observation and Assessment System supporting Sustainable Development” (2009-2013) of the 7 th Framework Programme

Carabus (Procerus) scabrosus crimeanus Mazzi et Cavazzuti, 2014 was recorded in Melitopol (Zaporizhzhia Region, Ukraine). This subspecies has been previously recorded only from the Crimean Peninsula. Possible ways of its appearance in a new locality are discussed. Some data of its counts, distribution and biology are provided.

Summary Purpose of the work was to generalise the experience of GIS-technologies use to establish an effective system for visualisation and analysis of study results of the unique Island Zmiinyi in the northwestern Black Sea (NWBS). Methodology of the data analysis and processing included bathymetric surveys using sonar and ArcGIS software for Digital Elevation Model (DEM) development and mapping of the main characteristics of the island and coastal ecosystems. Results. The DEM of the Zmiinyi Island and the adjacent shelf was based on the “Zmiinyi Island” GIS-system comprising the blocks of: (i) information accumulation, processing and management, (ii) archives of maps and measurement data, (iii) visualization and preparation of cartographic material, as well as (iv) updatable set of thematic maps (layers). The results of comparison between the available cartographic material and the developed bathymetric maps demonstrated good convergence with the 1:50000-scale map and significant disagreements at generation of the larger scale raster maps. Some examples of thematic maps (layers) development were presented. Conclusions. Use of GIS technologies for analysis of monitoring data on the ecosystems of Zmiinyi island and adjacent shelf increase significantly the speed and quality of data analysis and their representativeness and highly recommended for other areas of NWBS.

The future space-based γ-ray telescope GAMMA-400 will be installed on the Navigator platform of the Russian astrophysical observatory. A highly elliptical orbit will allow prolonged (~100 days) continuous observations of many regions of the celestial sphere for 7–10 years. GAMMA-400 will measure fluxes of γ‑ray emission in the energy range of ~20 MeV to several TeV and electrons + positrons to ~20 TeV. The γ-ray telescope will have excellent separation of γ-ray emissions against the background of cosmic rays and electrons + positrons from protons, along with unprecedented angular (~0.01° at Eγ = 100 GeV) and energy (~1% at Eγ = 100 GeV) resolutions 5–10 times better than for the Fermi-LAT and ground-based γ-ray telescopes. GAMMA-400 observations will provide fundamentally new data on discrete sources and spectra of γ-ray emissions and electrons + positrons.

The GAMMA-400 γ-ray telescope installed at the Russian space observatory is intended for precision measurements in the energy range of 20 MeV–1000 GeV of γ-ray emission (with the angular and energy resolutions several times better than that of current γ-ray telescopes) from discrete sources; measurement of the energy spectra of Galactic and extragalactic diffuse γ-ray emission; studies of γ-ray emission from the active Sun; and measurements of fluxes of γ-ray emission and electron–positron cosmicray component, which are probably associated with the annihilation or decay of dark-matter particles.

An analysis of the state of equipment of 72 outdated coal HPP (heat power plants) of a total capacity 14.3 GW with steam parameters before the turbines pbefore ≤ 9 MPa, tbefore = 420–540°С was performed. The equipment is characterized by a considerably low efficiency factor, even if it were converted to burning the natural gas, and by increased release of harmful substances. However, on the most part of the considered HPP, the steam turbines, unlike the boilers, have thus far retained the operation applicability and satisfactory reliability of performance. The analysis has shown that it makes sense to effectively modernize the outdated coal HPP by transformation of their equipment into combined-cycle plant (CCP) with coal gasification, which has high economic and ecological indicators due to thermodynamic advantage of the combined cycle and simpler purification of the generator gas in the process under pressure. As the most rational way of this transformation, the one was recognized wherein—instead of the existing boiler (boilers) or parallel to it—a gasification and gas turbine system is installed with a boiler-utilizer (BU), from which steam is fed to the HPP main steam pipe. In doing this, the basic part of the power station equipment persists. In the world, this kind of reconstruction of steam power equipment is applied widely and successfully, but it is by use of natural gas for the most part. It is reasonable to use the technology developed at Heat Engineering Research Institute (HERI) of hearth-steam gasification of coal and high-temperature purification of the generator gas. The basic scheme and measures on implementation of this method for modernization of outdated coal HPP is creation of CCP with blast-furnace of coal on the basis of accessible and preserved HPP equipment. CCP power is 120 MW, input-output ratio (roughly) 44%, emissions of hazardous substances are 5 mg/МJ dust, 20–60 mg/МJ SO2, and 50–100 mg/МJ NOх. A considerable decrease of specific CCP cost is expected: down to approximately half compared to that of CCP with coal gasification created elsewhere abroad. Verification and debugging of accepted solutions can be carried out at a small-scale pilot plant.

The future space-based GAMMA-400 gamma-ray telescope will be installed on the Navigator platform of the Russian Astrophysical Observatory. A highly elliptical orbit will provide observations for 7-10 years of many regions of the celestial sphere continuously for a long time (~ 100 days). GAMMA-400 will measure gamma-ray fluxes in the energy range from ~ 20 MeV to several TeV and electron + positron fluxes up to ~ 20 TeV. GAMMA-400 will have an excellent separation of gamma rays from the background of cosmic rays and electrons + positrons from protons and an unprecedented angular (~ 0.01° at Eγ = 100 GeV) and energy (~ 1% at Eγ = 100 GeV) resolutions better than for Fermi-LAT, as well as ground-based facilities, by a factor of 5-10. Observations of GAMMA-400 will provide new fundamental data on discrete sources and spectra of gamma-ray emission and electrons + positrons, as well as the nature of dark matter.

The GAMMA-400 currently developing space-based gamma-ray telescope is designed to measure the gamma-ray fluxes in the energy range from ∼20 MeV to several TeV in the highly elliptic orbit (without shadowing the telescope by the Earth) continuously for a long time. The physical characteristics of the GAMMA-400 gamma-ray telescope, especially the angular and energy resolutions (at 100-GeV gamma rays they are ∼0.01° and ∼1%, respectively), allow us to consider this space-based experiment as the next step in the development of extraterrestrial high-energy gamma-ray astronomy. In this paper, a method to improve the reconstruction accuracy of incident angle for low-energy gamma rays in the GAMMA-400 space-based gamma-ray telescope is presented. The special analysis of topology of pair-conversion events in thin layers of converter was performed. Applying the energy dependence of multiple Coulomb scattering for pair components, it is possible to estimate the energies for each particle, and to use these energies as weight in the angle reconstruction procedure. To identify the unique track in each projection the imaginary curvature method is applied. It allows us to obtain significantly better angular resolution in comparison with other methods applied in current space-based experiments. When using this method for 50-MeV gamma rays the GAMMA-400 gamma-ray telescope angular resolution is about 4°.

This article examines leasing relations in the Russian construction industry. Leasing is a less costly form of effective equipment of construction companies. The article studies legislative and regulatory acts reflecting the government’s desire to develop leasing relations in Russia. A comparative analysis of leasing and credit relations is based on the following indicators: loan term, payment schedule, bond, depreciation, accelerated depreciation rate, property tax, VAT, insurance. The article proposes a mechanism for updating the material and technical base of construction organizations, taking into account state regulation of the process of restoring and leasing equipment. It is recommended to create a repair and maintenance base for construction equipment. An example of purchasing a bulldozer used in most construction organizations is provided. The use of this mechanism is widely used in foreign countries. In the Russian Federation, centralized restoration of equipment and its resale to construction companies is not used. Therefore, the mechanism proposed will make it possible to eliminate the lack of production capacity and increase the level of equipment of construction companies.

The GAMMA-400 gamma-ray telescope is planned for the launch at the end of this decade on the Navigator service platform designed by Lavochkin Association on an elliptical orbit with following initial parameters: an apogee ~300000, a perigee ~500 km, a rotation period ~7 days and inclination of 51.4°. The apparatus is expected to operate more than 5 years, reaching an unprecedented sensitivity for the search of dark matter signatures and the study of the unresolved and so far unidentified gamma-ray sources. An electronics system, which consists of 14 front-end multichannel electronics modules and the main processing unit with a total power consumption of about 400 W (74W for main processing unit), has been developed for providing fast trigger and veto for the data taking to the experiment. The communication between front-end modules, main processing unit and scientific data acquisition system of the gamma-ray telescope is performed via high-speed SPACEWIRE network. To assure the long-term reliability in space environment, a series of critical issues such as the radiation hardness, thermal design, components and board level quality control, warm and cold redundancy are taken into consideration. The main design concepts for the system, measurements setups together with some test results are presented.

The future GAMMA-400 γ-ray telescope will provide fundamentally new data on discrete sources and spectra of γ-ray emissions and electrons + positrons due to its unique angular and energy resolutions in the wide energy range from 20 MeV up to several TeV. The γ-ray telescope consists of the anticoincidence system (AC), the converter-tracker (C), the time-of-flight system (S1 and S2), the position-sensitive and electromagnetic calorimeters (CC1 and CC2), the scintillation detectors of the calorimeter (S3 and S4) and lateral anticoincidence detectors of the calorimeter (LD). To extend the GAMMA-400 capabilities to measure γ-ray bursts, Monte-Carlo simulations were performed for lateral aperture of the one of the versions of GAMMA-400. Second-level trigger based on signals from CC2, LD, S3, and S4 allows us to detect γ-ray bursts in the energy range of ~10-300 MeV with high effective area about 1 m2.

Our paper reviews the planned space-based gamma-ray telescope GAMMA-400 and evaluates in details its opportunities in the field of dark matter (DM) indirect searches. We estimated GAMMA-400 mean sensitivity to the diphoton DM annihilation cross section in the Galactic center for DM particle masses in the range of 1-500 GeV. We obtained the sensitivity gain at least by 1.2-1.5 times (depending on DM particle mass) with respect to the expected constraints from 12 years of observations by Fermi-LAT for the case of Einasto DM density profile. The joint analysis of the data from both telescopes may yield the gain up to 1.8-2.3 times. Thus the sensitivity reaches the level of annihilation cross section $\langle \sigma v \rangle_{\gamma\gamma}(m_\chi=100~\mbox{GeV})\approx 10^{-28}$ cm$^3$/s. This will allow us to test the hypothesized narrow lines predicted by specific DM models, particularly the recently proposed pseudo-Goldstone boson DM model. We also considered the decaying DM - in this case the joint analysis may yield the sensitivity gain up to 1.1-2.0 times reaching the level of DM lifetime $\tau_{\gamma\nu}(m_\chi=100~\mbox{GeV}) \approx 2\cdot 10^{29}$ s. We estimated the GAMMA-400 sensitivity to axion-like particle (ALP) parameters by a potential observation of the supernova explosion in the Local Group. This is very sensitive probe of ALPs reaching the level of ALP-photon coupling constant $g_{a\gamma} \sim 10^{-13}~\mbox{GeV}^{-1}$ for ALP masses $m_a \lesssim 1$ neV. We also calculated the sensitivity to ALPs by constraining the modulations in the spectra of the Galactic gamma-ray pulsars due to possible ALP-photon conversion. GAMMA-400 is expected to be more sensitive than the CAST helioscope for ALP masses $m_a \approx (1-10)$ neV reaching $g_{a\gamma}^{min} \approx 2\cdot 10^{-11}~\mbox{GeV}^{-1}$. Other potentially interesting targets and candidates are briefly considered too., Comment: 26 pages, 8 figures

The task of selecting neutral γ rays from the background of charged particle fluxes, which arises in investigation of high-energy (>50 GeV) cosmic rays, is complicated by the presence of the backsplash effect. The backsplash is composed of a great number of low-energy (~1 MeV) particles produced in an electromagnetic shower being developed in the calorimeter of the γ-ray telescope. A technique of charged particle rejection using an anticoincidence system has been developed. A method for discriminating events of charged particle detection from γ-ray detection events accompanied by the backsplash phenomenon is proposed. This method is based on the difference of the signals in time and makes it possible to maintain a high detection efficiency even for high-energy γ rays.

We have carried out thermodynamic modeling of the GaI3–S and ZnI2–S systems by the method of equilibrium constants and calculated the chemical compositions of the condensed and vapor phases in the temperature range 200–500°C. Our experimental data demonstrate the feasibility of preparing zinc thiogallate by reacting gallium(III) iodide and zinc(II) iodide with sulfur. Synthesis was carried out at a temperature of 450°C over a period 2 h, followed by calcination of the product at 650°C in order to remove the residual iodine. The practical ZnGa2S4 yield was 92–94%.

Adhesion of As–S and As–Se glasses to silica glass is studied by means of the steady detachment method. The results demonstrate that the adhesion strength of the boundary of solid phases increases with the content of chalcogens in the composition of glass. It is found that adhesion of arsenic sulfide glasses with sulfur content over 65% to silica glass exceeds the tensile strength of the silica glass during the process of solidification and annealing of chalcogenide preforms. The adhesion of arsenic chalcogenides to silica glass is determined to be the reason of chalcogenide glass contamination by heterophase inclusions.

We have investigated the coprecipitation of tellurium(IV), tungsten(VI), and lanthanum(III) hydroxides through the addition of aqueous ammonia to a mixture of tellurium dioxide, lanthanum oxide, and tungstic acid solutions in hydrochloric acid. The effects of initial solution composition and precipitation pH on the composition of the precipitate have been assessed. It has been shown that the composition of the precipitate is essentially identical to that of the starting solution if the relative contents of lanthanum and tungsten in the mixture are within 20 mol % and precipitation is ceased at pH 7.

Results are considered for a study of basic power steel corrosion rate in a producer gas atmosphere and a method is proposed for its calculation under industrial conditions.

An empirical technique is developed for calculating fuel gasification in a hearth gas generator and tested on a small experimental-industrial gas generator. The results agree with experimental data. It is proposed that this technique be used for calculations of large gas generators after it has been optimized.

The paper considers for the first time the morphology, composition, and conditions of formation of the greisens of the Solnechnoe deposit (Komsomol’sk ore district), a typical cassiterite–silicate assemblage. The greisens are localized in the root parts of the deposit and represent a system of veins and veinlets formed in the contraction fractures of the metasomatically altered roof of the monzogranite intrusion (age of 94–92 Ma). The cassiterite–chlorite–carbonate–muscovite–quartz composition of the greisens with admixture of topaz, fluorite, and apatite reflects the composition of the monzogranites. The greisens are close in age (85.3 Ma on muscovite) to the granitic aplites (80–85 Ma on the whole-rock and biotite) of the final phase of the intrusive magmatism. The fluid regime of their formation differs from that of the economic ores in higher temperature, pressure, and salinity. One distinguishing feature of the greisens is elevated contents of LREE, U, and Th, which are incorporated in the REE fluorcarbonates, thorite, and uranothorite crystallizing together with cassiterite.

The GAMMA-400 project will be the new generation of satellite gamma-observatory. GAMMA-400 space-based gamma-ray telescope represents the core of the scientific complex intended to perform a search for signatures of dark matter in the cosmic gamma-emission, measurements of diffuse gamma-emission characteristics, investigation of extended and point gamma-ray sources, studying of high energy component of gamma-ray bursts and solar flares emission. Four fast plastic sub-detectors of the gamma-ray telescope are included in fast trigger logic in the main telescope aperture. This aperture expected angular and energy resolution are ∼0.01° and ∼1-2% respectively for gammas with the energy >100 GeV and electron/protons rejection factor ∼5-105. Prototype of anticoincidence detector based on long BC-408 scintillators with SiPM readout for gamma-ray telescope was tested on a 300 MeV secondary positron beam of synchrotron C-25P «PAKHRA» of Lebedev Physical Institute in Russia. The measurement setup, design concepts for the prototype detector and chosen solutions together with some test results are discussed. Two other apertures (additional and lateral) allow analyzing transient events not required precision angular resolution, for examples, GRBs and solar flares. Similar plastics sub-detectors included in their fast trigger logic. Using of all three apertures allows making more effective observations of GRBs (better signal to noise ratio), more detailed study of its high energy afterglow due long term measurements (because of high apogee orbit provides low background variations with time) and detailed analysis of the sources luminosity variability (spectral, angular and temporal).

Different types of light concentration for large fast scintillation detectors with silicon photomutipliers as photosensors for the satellite based gamma-ray telescope GAMMA- 400 are analysed. Some proposals for their possible implementations are made.

We have investigated the coprecipitation of tellurium(IV), molybdenum(VI), and lanthanum(III) hydroxides from hydrochloric acid solutions of compounds of these elements and found conditions under which the precipitate was identical in composition to the starting solution of macrocomponents.

We have investigated the coprecipitation of tellurium(IV) and tungsten(VI) compounds through the addition of aqueous ammonia to a mixture of a tellurium dioxide solution in hydrochloric acid and tungstic acid. We have revealed general trends in the distribution of macrocomponents between the precipitate and solution and demonstrated the feasibility of proportional tellurium(IV) and tungsten(VI) precipitation in the pH range from 2 to 7.