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Materials based on molybdenum-aluminium-carbon compounds have a considerable potential for use under intense wear conditions at elevated temperatures. This paper presents the experimental results of self-propagating high-temperature synthesis of compounds within the Mo-Al-C system. By combining two processes: SHS of the elements and SHS-metallurgy, cast materials containing the Mo3Al2C, Mo2C, Mo3Al, and Mo3Al8 phases were obtained. The experiments used mixtures with compositions calculated according to the ratio (1 - α)(3MoO3-8Al-C)/α(3Mo-2Al-C), where a varied in the range from 0 to 1. The synthesis was carried out in a laboratory reactor of 3 L volume at an initial argon pressure of 5 MPa. The mass of the initial mixtures in all experiments was 20 g. The process of combustion was initiated by a 0.5 mm diameter molybdenum wire spiral by applying 28 V voltage to it. The resulting end products were studied by X-ray diffraction and local microstructural analysis. A significant influence of the ratio of the initial reagents on the synthesis parameters, phase composition, and microstructure of the target products was established. Introduction into the high-exothermic mixture 3MoO3-8Al-C inert “cold” mixture 3Mo-2Al-C leads to an increase in the content of carbide phases in the ingots. The possibility of obtaining cast materials based on the triple phase Mo3Al2C, the maximum content of which is 87 wt. % at the content of the “cold” mixture in the charge α = 0.4 is shown. The presence of secondary phases of molybdenum carbide (Mo2C) and molybdenum aluminides (Mo3Al8 , Mo3Al) in the final products is due to a change in the composition of the initial mixture caused by the ejection of components during combustion and insufficient existence time of the melt formed in the combustion wave.

The aim of the study was to analyze the resistance of 21 Microdochium nivale strains (fungi that cause pink snow mold in winter crops), living within a single area and a single crop (winter rye), to fungicides that differ in chemical nature and mechanisms of action as well as to test the interconnection between levels of virulence and fungicide resistance of strains. The virulence of M. nivale strains was determined on detached leaves of rye (Ogonek variety) plants as well as on whole plants grown under sterile conditions in vitro. The resistance of strains to fungicides (Provisor (a.s. azoxystrobin) and Ferazim (a.s. carbendazim)) was determined by inhibition of mycelium growth. As a result of the experiments, more strains (13) capable of growing in the presence of Provisor were revealed than Ferazim-resistant strains (2); however, Ferazim-resistant strains had a greater level of resistance (5-16% of growth inhibition) than Provisor-resistant strains (63-94 % of growth inhibition). A negative correlation (Spearman's correlation coefficient -0.604 and -0.532) between the level of virulence of M. nivale strains and the level of their susceptibility to Provisor was found. This evidently means that the acquisition of resistance to Provisor by M. nivale strains is accompanied by an increase in their virulence. No correlations were found between the fungicide resistance of M. nivale strains and their attribution to one or another phylogenetic group, to which the strains were assigned based on the nucleotide sequence of the ITS2 (internal transcribed spacer 2) region. The study shows that for choosing the fungicide application strategy, it is necessary to analyze phytopathogen populations for the presence of strains that are simultaneously characterized by high virulence and resistance to various fungicides and also take into account that the adaptation of fungi to certain fungicides can be accompanied by an increase in their virulence, which will negatively affect the phytopathological state of agrocenosis.

Introduction . New provisions, introduced into building regulation codes, necessitate a revision of the set of rules titled “Fire protection systems. Fire resistance of protected items” in respect of fire resistance limits and fire hazard classes of building structures, dimensions of fire compartments, as well as their detailed elaboration with account taken of the characteristics of buildings that perform different functions. Goals and objectives . The purpose of the article is to substantiate the revised provisions of the set of rules “Fire protection systems. Fire resistance of protected items” with account taken of the new provisions of building regulation codes. Methods . An analytical method is used to formulate and substantiate the requirements for a fire protection system based on the comprehensive evaluation of provisions of the Federal Law of the Russian Federation dated July 22, 2008 No. 123-FZ “Technical Regulations of Fire Safety Requirements” (hereinafter — No. 123-FZ) and provisions of building regulation codes. Results . The contribution of the work results to the new edition of the set of rules JV 2.13130.2020 “Fire protection systems. Fire resistance of protected items” ensures the harmonization of this document with the requirements of building regulation codes. Conclusion . The research findings allow to optimize the requirements for fire resistance limits, fire hazard classes of building structures, and the size of fire compartments. The research results also help to clarify these requirements with regard for the characteristics of buildings that perform different functions.

The aim of the research was to study the weather risks when growing the main commercial citrus crop, mandarin, in the subtropics of Russia. The most informative sources for a complex of environmental factors are temperature and precipitations. The characteristics of the main weather factors are given, which can determine both the optimal growing conditions for the mandarine ( Citrus reticulata Bl. var. unhiu Tan . ) varieties ‘Unshiu’, ‘Iveria’, ‘Kovano-Vase’, ‘Miagava-Vase’, and limiting factors of plant cultivation in the studied region. Phenological observations have established that the first phase of “budding” depends on the sum of temperatures in March-April. It was 113 ° C in 2015, 225 °С in 2016, 183 °С in 2017 and 244 °С in 2018. Flowering begins in May-June when the sum of effective temperatures reaches 502 °С, at min 490 °С and max 512 °С. The duration of the full period, from «budding» to «fruit ripening», varies depending on weather conditions: temperature, precipitation, and can last from 170 to 191 days. A more significant role in the timing of the onset and duration of the phenological phases of mandarin development is played by the water-thermal regime of the year. Weather factors manifested themselves on the growth processes of the studied varieties of mandarin. The total length of growth in ‘Iveria’ and ‘Kovano-Vase’ was higher than that in ‘Unshiu’ and ‘Miagawa-Vase’. The same feature was noted in the growing shoots of the vigorous variety ‘Unshiu’, it was 8.5 cm, and of the medium-sized ‘Iveria’ — 7.5 cm. For the dwarf forms ‘Kovano-Vase’ and ‘Miagawa-Vase’ it was 7.5 cm and 6.8 cm respectively. Weather conditions and the limiting factor (lack of atmospheric precipitation) have a negative impact not only on the timing of the main phenological phases of mandarin development (flowering, second growth of shoots), but also on their productivity.

In recent years, myelosai (milleran) has become widely used to treat patients with chronic myelosis.

The paper presents the results of research aimed at the fatigue evaluation of airframe elements made of aluminum alloys damaged by corrosion. Fatigue tests of the samples and metallographic studies were performed. The results of multi-year research on the effect of corrosion damage on the fatigue performance of aluminum alloys were summarized, and an observed dependence was established between the corrosion damage parameter and the material characteristics.

The vitality structure of forest stands and the annual radial increment of Scots pine trees of different vital state categories growing in the northern taiga middle-aged lichen pine forests and woodlands of the Kola Peninsula have been studied. This study has shown a prevalence (60–75%) of weakened and strongly weakened trees in the Scots pine forests and woodlands; the fraction of healthy trees does not exceed 15–20% (30% in terms of the stand volume). In the age range of 30–85 years, the radial growth of Scots pine trees in the communities studied decreases 1.5- to 3.5-fold, and the annual basal area increases 1.5- to 5-fold. Differentiation of trees of differing vitality in relation to the radial increment is clearly manifested starting from 50 years after the fire. The ratio between the annual basal areas of healthy, weakened, strongly weakened, and dying trees in pine forests and woodlands is 8 : 5 : 2.5 : 1 and 11 : 5.5 : 3.5 : 1, respectively. The difference between the resource potentials of pine woodlands and forests is 1 : 1.6 and is manifested at the level of communities, but not at the level of individuals.

We report the results of theoretical and experimental studies of a digital system for regulating and stabilising the frequency of a four-frequency Zeeman laser gyroscope (ZLG), in which generation occurs simultaneously on two longitudinal modes with orthogonal circular polarisations; therefore, four light waves propagate in the optical ring resonator. In contrast to a two-frequency Zeeman laser gyroscope, a four-frequency ZLG does not use the intensity modulation signal of one of the light waves, which appears when an alternating magnetic field is applied to the active medium, to analyse the frequency detuning of longitudinal modes from the centre of the active-medium gain contour. At the same time, it is possible to construct a digital perimeter adjustment system (PAS), which allows the resonator perimeter to be adjusted so that the magnetic components of the zero drift of the gyroscope for two longitudinal generation modes are equal and opposite in sign. Due to this, almost complete compensation for the magnetic component of the zero drift of the gyroscope is realised in a four-frequency ZLG. The use of the digital system makes it possible to provide a higher accuracy of the resonator perimeter adjustment than that in a two-frequency ZLG, even with a relatively small bit capacity of the PAS digital-to-analogue conversion (DAC), and to fully take advantage of the capabilities of a four-frequency ZLG to reduce the magnetic sensitivity.

The article indicates pomological signs of tangerine: peel and pulp color, number of slices, fruit size, shape, taste, aroma and juiciness of a fruit. Physicochemical characteristics of tangerine fruits are shown: sugar, acidity, dry matter, vitamin C. A comparative biochemical assessment of tangerine fruits growing in the subtropical zone of the Krasnodar Territory and imported ones is carried out. The studies have been carried out in VNIIITsiSK in Sochi.6 tested varieties of imported tangerine fruits were infected with penicillosis (Penicillium expancym Link) and anthracnosis (the pathogenic agent is Colletotrichum gloeosporioides Penz. Fungus). A physiological peta disease (deep pit) was found, which affected fruits on trees and appeared during storage with temperature regime violation [13]. Biochemical analysis revealed a low concentration of ascorbic acid, acidity and an increased content of dry soluble substances in the imported fruits in comparison with fruits grown in the humid subtropics of Russia.

Technical carbon CH210 was processed by chemical reduction of the diazo derivative of anthraquinone for surface modification. The presence of anthraquinone groups on the carbon surface was confirmed by attenuated total internal reflection (ATR) IR spectroscopy. Carbon with the anthraquinone-modified surface was deposited on a glassy carbon support using a polymer binder. The behavior of the thus obtained catalyst in oxygen electroreduction in an alkaline medium was studied by the rotating disk electrode method. The kinetic characteristics of the reaction were determined: half-wave potential, limiting current, number of electrons, Tafel slope, exchange current, and charge transfer coefficient. Hydrogen peroxide is formed on the surface of the carbon–polymer composite at higher positive potentials than on technical carbon and glassy carbon electrodes. Therefore, the proposed material can be used as an effective electrocatalyst for this reaction.

Cast composite material based on Cr2AlC MAX phase has been prepared by metallothermic self-propagating high-temperature synthesis (SHS) from a mixture of powders of chromium oxide, aluminum, and carbon. The experiments have been performed using an SHS reactor with a volume V of 3 L under an excess inert gas (Ar) pressure (P = 5 MPa). The prepared material has been studied by X-ray diffraction analysis, scanning electron microscopy, and local microstructural analysis. The quantitative analysis has been performed by the Rietveld method. The electrical resistivity was measured in the 100–1300 K temperature range. The resulting material is an electrical conductor with metallic conductivity in the 100–1300 K temperature range, and has the electrical resistivity of the same order as the samples containing 100% Cr2AlC.

The new empirical method was developed for estimating the relative contribution of the deterministic, chaotic and noise components in the time series of the accident rate of aircraft in the Armed Forces of the Russian Federation. The behavior analysis of the senior Lyapunov exponent dependencies on the parameter of “number of neighbors used” specified in the algorithm in the case of model series (deterministic, chaotic and colored noise series) enabled to estimate the boundaries of numerical values of the parameters typical for these types of series and then apply them to the noise percentage analysis in the real series of the aviation events number.

Three-body continuum p-p-α for the charge exchange reaction 1H(6Li,6Be)n is studied in detail. The data are obtained with a high volume of statistics (approximately 4.7 million events), making it possible to analyze three-particle correlations. Detailed information about the structure of 6Ве and the reaction is obtained as a result.

We develop a universal method of physicochemical refining of the market wood pulp to the level given by the requirements of State standards for fibrous semi-finished products for deep chemical processing into various functional derivatives and artificial materials (Na-CMC, colloxylin, pyroxylin, viscose and cordage fibers). An experimental laboratory modular setup was designed and manufactured at the Semenov Institute of Chemical Physics (RAS). The modification includes the following stages: preparation of the raw materials, chemical modification, washing, and drying of the final product. At the first stage the original market pulp was dispersed to obtain a homogeneous suspension, cleaned and dried. After washing, the refined cellulose was dried in two stages: i) microwave drying to a moisture content of 45 - 50%; ii) convective drying with warm air to a moisture content of 5 - 9%. The basis of chemical modification is the stage of cold refining. Compared to other methods of refining wood pulp (acid-alkali treatment, hot refining) cold refining does not require special equipment which operate at elevated temperature and pressure. The developed procedure of physicochemical modification of the market wood pulp is universal, since it has no restrictions on the brand of the initial raw material. Depending on the quality requirements to the final product, the proposed method provides obtaining all brand of cellulose for chemical processing — viscose cellulose, acetate cellulose, cord cellulose. Mass fraction of the alpha-cellulose in the final product ranges from 93 to 99%.

Changes in characteristics of the upper soil horizons in dark coniferous forests in the course of their postfire restoration were assessed. The studies were carried out in the northern taiga forests exposed to fire 8 to 400 years ago in the Kola Peninsula and in the middle taiga forests burned 70 and more than 500 years ago in the northern Cis-Ural region (Pechoro-Ilychskii State Biospheric Reserve). Samples from 23 soil pits on 20 test plots were analyzed. The actual acidity, loss on ignition, contents of exchangeable K, Ca, and Mg and mobile Mn, Fe, and Zn were determined. Two boundaries (~80 and 160–200 years after fire) and three main periods in the postfire dynamics of the upper soil horizons properties were established. The ash and Fe content in the litter was found to decreases about 80 years after the fire. In 160–200 years after fire, the thickness of the forest litter is restored and stabilized at the level of about 9.7 (8.3–10.4) cm; the pH value and the Ca, K, and Mn concentrations in the litter become lower. Thus, it can be concluded that the properties of soils under dark coniferous forests of the European North considerably change in the course of postfire successions.

The main problems of establishment a slow growth in vitro collection of citrus and other tree crops cultivars are high degree of fungal contamination of bud explants and low growth potential of shoots. In this regard, the aim of current research is to assess the efficiency of decontamination procedure and the possibility of tissue culture initiation and slow growth conservation of valuable lemon cultivars. The best results of surface sterilization were obtained using immersion solutions of 0.3 % Veltolen – 25 minutes or 10 % Domestos – 25–30 minutes. In these treatments, 27.7–33.0 % of aseptic explants were obtained, respectively. However, after the third subculture, the yield of aseptic viable explants decreased till 10 % as a result of secondary contamination by endophytic fungi. The addition of biocide (“Gavrish”) in a nutrient medium at a concentration of 1 ml/l helped to increase the yield of aseptic viable explants till 50 %. However, after the third subculture the photosynthetic activity and the pigments content as well as growth rate decreased. Plants dropped yellowish leaves and eventually died. Thus, 37.35 % of plantlets survived after 8 months of conservation, and only 14.6 % survived after 10 months. Even after the third month of conservation significant decrease in the viability index and the coefficient of photosynthetic activity occurred in plants. Chlorophyll a in leaves decreased from 1.59 to 1.14 mg/g during 12 months in vitro conservation. The similar tendency observed on clorophyll b and carotenoids content. The experiments were carried out for 5 years using different lemon cultivars and other citrus varieties and cultivars. Thus, micropropagation and slow growth in vitro conservation of valuable lemon cultivars are still problematic and requires new technical solutions due to the low growth potential of plantlets raised from the mature buds that is consistent with the data of other researchers.

Bacterial SpoT-dependent SR was activated in Pectobacterium atrosepticum when pathogen infected potato as well as tobacco plants. Pba induced plastid stringent response in tobacco plants, but not in potato plants. Jasmonic acid defense pathway was activated in tobacco plants, provoking rapid maceration of plant tissues. Salicylic acid defense pathway was induced in potato plants, probably ensuring a more prolonged coexistence of the phytopathogen with its host.

The specific energy parameters of nanostructured electrode materials of electrochemical capacitors obtained by the method of multistage calendering are studied in this work. The dependence of electrical conductivity; the specific capacity of an electrical double layer of electrodes; and the internal resistance of electrochemical capacitors on the nature, quantity, and spatial localization (in the volume of the active layer and/or at the active layer–current collector interface) of conductive dopants (carbon black and grown in vacuum carbon fibers) are examined.

The redox sorption of molecular oxygen from water by a thin granular layer of a copper-ion exchanger nanocomposite in the currentless mode and under cathodic polarization is studied. The speed of propagation of the boundaries of the chemical reaction of stepwise oxidation of copper nanoparticles under the conditions of polarization slows considerably. At the same time, the amount of electrochemically regenerated copper from the resulting oxides that is capable of interacting with oxygen again grows. The stationarity of the redox sorption of oxygen is due to the equality of the rates of oxidation and reduction of the metallic component of the composite.

Characterization of genetic diversity in germplasm collections is fundamental for an efficient management and utilization. The citrus germplasm in the Western Caucasus represent one of the most northerly citrus collections. The collection contains numerous cultivars specifically selected for frost-tolerance, which are valuable as genetic resources for citrus breeding programs worldwide. Currently, the field citrus collection consists of more than 200 accessions, but their taxonomic assignment, genetic structure and diversity has not been clarified. In our study, 130 different citrus accessions including 24 species or interspecific hybrids maintained and bred at the Federal Research Centre the Subtropical Scientific Centre of the Russian Academy of Sciences (FRC SSC RAS) were genetically investigated using 13 biparental (ncSSR) and 13 uniparental (orgDNA) markers. After STRUCTURE analysis, the single accessions were allocated to eight genetic clusters and their relationships were elucidated. This phylogenetic relationship was also confirmed by principal coordinates analysis (PCoA) and by dissimilarity analysis using DARwin. We identified twenty accessions as misclassified and reassigned them to the correct species. For the remaining 110 accessions the taxonomical assignment could be confirmed. A high genetic diversity was observed on basis of the nuclear ncSSR markers, while the detection of 19 different haplotypes allowed the distinct differentiation of the accessions within our collection. Our study showed that the combination of ncSSR and orgDNA was an efficient tool to estimate the genetic diversity, genetic structure and phylogeny in the FRC SSC RAS citrus germplasm collection. The results obtained are valuable for future management of the collection and the usage of individual accessions as genetic resource for citrus cultivar and rootstock breeding, especially in colder regions.

The goal of this work was to improve the efficiency of early detection of microcalcifications, the earliest indicators of breast cancer. Studies have shown that the presence of isolated clustered microcalcifications in the mammary gland significantly increases the range of variation of effective atomic number and considerably changes its distribution. Conventional, subtraction, or dividing mammography or their linear convex combination may fail to visualize isolated clustered microcalcifications. However, the presence of microcalcifications in the mammary gland can be determined analytically from the distribution of the extreme terms of an ordered series of effective atomic numbers in the mammary gland. Then, the coordinates of the isolated clustered microcalcifications can be calculated. The distribution of the effective atomic numbers in healthy tissue without microcalcifications is symmetric and close to normal, while breast tissue with even a single isolated cluster of microcalcifications is characterized by an asymmetric distribution and high values of the maximum effective atomic numbers. An algorithm for calculating the coordinates of isolated microcalcifications is suggested.

When fire extinguishing foam is applied for fire suppression of flammable liquid in the tank, after the most part of the liquid mirror is already covered by a fire extinguishing foam layer, the fuel continues to burn at the side of the tank. This rather complex case is often implemented in practice, but it wasn’t fully described in the existing theoretical literature. Extinguishing of these last fire sources occur in the following two cases: § cooling of a free side of the tank to a temperature at which the side heated by flame ceases to serve as a source of ignition of fuel vapors; § lowering of the temperature of the combustible fluid located at the side surface of the reservoir to a temperature at which the ignition of the combustible mixture formed by mixing of the fuel vapor with air can not occur. The article presents the analysis of the two cases needed to extinguish remaining pockets of burning at the side of the tank. For the first case (cooling of a free side of the tank to a temperature at which the side heated by flame ceases to serve as a source of ignition of fuel vapors), the mathematical model describing the temperature change during the cooling of the sides of the reservoir was developed. Analytical solutions with certain assumptions were obtained. The expression that defines the time of extinguishing of flammable liquid was also obtained. The values of heat transfer coefficient calculated with the usage of the resulting equation together with the available experimental data obtained in the burning tank, are presented in the paper. The values of the heat transfer coefficient are 0.34¸0.51 W·m -2 ·K -1 . For the second case (lowering of the temperature of the combustible fluid to a temperature at which the ignition of the combustible mixture can not occur), the resulting expression describes changes in temperature of the side of the tank during cooling by fire extinguishing foam. The expression was derived from the heat equation with a number of assumptions and the usage of integrating methods of research of physical processes involving integral relations derived from the analysis of differential equations. The obtained equation of temperature change of the side of the tank while cooling by fire suppression foam during extinguishing of flammable liquid, can be later used in the modeling of processes of extinguishing of tanks and in calculating of the flow rate of the foam.

The modern history of organic farming in Russia began in 1989 with the implementation of the state program “Alternative Agriculture”. Organic agriculture in Russia was initially considered as a condition and mechanism for the development of small and medium agricultural forms of production. The increase in the production of agricultural products and food in excess of the normative requirements, ensuring the country’s food security led to the expansion of exports. Russia’s aptitude to uphold fulfillment with global standards and be competitive in world markets where ecologically clean agricultural products are in demand is quite high: huge reserves of land in Russia, the introduction of ecological farming systems must be carried out on huge areas, coordinated with a large number of small owners. Information support for farmers about new, more efficient technical means, biotechnologies in organic agriculture and certification of organic products for environmental friend-liness, safety of manufactured products, the use of intensive biotechnologies, financial support of organic agriculture, processing and sale of organic products remain problematic.

The idea of creating a laser thermonuclear installation was considered back in 1960s by Basov N and Krokhin O. [1]. Facility for conducting research near DT-fuel ignition threshold is being commenced at the moment [2], assembly of the laser installation interaction chamber has already been completed. To focus laser sight on the target, off-axis aspherical lenses are used as part of the final optical module (FOM). These lenses are manufactured using the developed technology of forming off-axis aspherical surfaces of optical parts. Combined use of shaping technology and stand for monitoring angular deviations of the surfaces of FOM lenses, allowed us to achieve high quality off-axis aspheric optical elements both in terms of standard deviation of the surface shape, as well as the value of the scattering circle.

The structure and key elements of the information model of horizontal steel tanks and underground tanks, on which the development of intelligent CAD systems are based, are described. The initial model inputs: functions, operating conditions, and basic dimensions of the constructed objects. The result: apparatus design variants that satisfy the initial data and the restrictions of the normative documents. The key elements of the information model: register of elements, model of structure, model of parameters, model of element positioning in space, and model of technical specifications of the designed equipment. A distinctive feature of the proposed model is use of If…Then… type of production rules. The model is designed for use at the stages of structural and parametric synthesis, construction of a 3D model, and drawing up of technical specifications of the designed objects with minimal involvement of the designer.

The report presents modern manufacturing technology of high-precision optical parts used in optical-electronic systems for various purposes. The report also presents the complex technology of automated shaping (TESAF) of aspherical, including off-axis surfaces of optical elements for optical-electronic systems. In this paper we consider various methods of forming optical parts with virtually any aspherization value and with different values of the off-axis parameter (off-axis aspheric), with the achievement of surface shape accuracy in the limit λ/60 ÷ λ/80 (λ = 0,6328 μm), by the criterion of the standard deviation. Optical systems manufactured by TESAF technology are already being successfully used at present.