Home – Home – Jornals – Combustion, Explosion and Shock Waves 2021 number 6

During the study, the structural adaptations of the desiccation-resistant homosporous fern Ceterach officinarum Willd were revealed at the organ and cellular-tissue levels. Among them, the main role is played by features that contribute to the maintenance of cell hydration. Xero-heliomorphic signs at the organ level: nanism, area reduction and leatheriness of fronds; dense cover of trichomes and scales. At the cellular-tissue level, water is retained due to the relatively thick blade of fronds, their small cells, a large number of cells per unit area and pycnomorphy, high values of the specific surface area of the fronds (UPW), dorsiventrality of the mesophyll, a relatively dense network of veins per unit area of the frond. Biochemical and functional - by increasing the concentration of osmotically active substances, lowering osmotic pressure, accumulation of water-retaining chemical compounds (catechins and tannins); on the phytocenotic - due to facultative bryophily. Sciomorphic features: at the cellular-tissue level - hypostomaticity, a relatively small number of stomata per unit area of frond, tortuous seams of epidermal cells, minimal values of the ratio of cell surface to volume. Mesomorphic features: differentiation of the mesophyll into columnar and spongy tissue, a thin cuticle layer on the surface of the epidermis, the presence of stomata in the lower epidermis. Another adaptation mechanism that determines the rhythm of fern development is the ability to inactivate life processes and fall into cryptobiosis under conditions of water stress and high temperatures. Unlike poikilohydric ectohydric bryophytes, the sporophytes of this fern, resistant to dehydration, can withstand drying out (and are, to this extent, poikilohydric), but are endohydric. In a word, the poikilohydricity of fern sporophytes is realized on a different structural basis, which is more evolutionarily advanced in comparison with thalloid plants. However, the frequent state of cryptobiosis, especially under conditions of alternating wet and long dry seasons, leads to an imbalance in carbon metabolism. Apparently, poikilohydricity is not the most perfect and productive way to combat drought.

The paper presents an overview of ontogeny of 11 life forms on the example of 16 species of boreal willows belonging to two ecological groups - alluvial and non-alluvial. At the intraspecific level, among the studied species, the greatest variety of life forms was found in alluvial species, and the smallest in non-alluvial species. In the species studied, polyvariety of evolution was revealed: structural and dynamic. As part of the structural polyvariety, morphological (as a result of which two or more (up to 4) life forms are formed in the adult state), dimensional (expressed in changing the size and life state of an individual within one ontogenetic state) are distinguished. Dynamic polyvariety is associated with different duration of pre-generative and generative periods of ontogeny. In all alluvial and most non-alluvial species, the predominance of the generative period of ontogeny over the generative one is observed. In individuals of two life forms of non-alluvial species, the pre-generative period prevails during ontogeny. Alluvial species have mastered a narrower range of environmental conditions compared to non-alluvial ones. At the intraspecific level, among the studied species, the greatest variety of life forms was found in alluvial species (2-4 life forms in each species), and the smallest in non-alluvial species (1-3 life forms in each species). Alluvial species are characterized by the presence of a small number of long shoots, a large number of shoots of medium length and a smaller number of short ones, which determines their high height compared to non-alluvial ones.

The ecological and geographical regularities of the spatial differentiation of the fauna of birds and mammals of the seas of northeastern Russia were studied at the end of the winter period of 1987-1988. The aerial surveys covered the Bering, Chukchi, East Siberian Seas, and the eastern part of the Laptev Sea. Mammals are ecologically associated with open sea areas, sea ice, continental and island coasts, and mainland tundra. Wintering flocks of birds form species of inland mountain streams, species common circumpolarly in the Holarctic tundra, marine species of the continental and island coasts of the North Pacific and the Arctic Ocean, including high-latitude endemics. 7 species of mammals and 23 species of birds have been registered. There are 22 bird species recorded exclusively in the Bering Sea (24 % of the marine avifauna of the Russian Far East). In terms of the number of species represented ( n = 9), auks prevail, which are very characteristic of the avifauna of the subpolar marine areas of the Palaearctic. Mammals have been regularly recorded in both the Arctic Ocean and the Pacific research sector. The winter fauna of mammals in the seas of northeastern Russia, in which the number of species is dominated by pinnipeds and cetaceans, makes up 23 % of the total mammalian fauna of this region. In the Bering Sea, 3 areas of concentration of wintering birds have been identified: in the southeast of Chukotka, southeast of Cape Navarin, south of about. St. Lawrence. The maximum density of the bird population (21.8 ind./km²) is in young ice and ice of primary education - where there are many forage polynyas. The population of birds of all types of ice is numerically dominated by fulmar, thin-billed and thick-billed guillemots. Most of the marine mammals were observed on the openings in the contact zones of different types of ice or in the ice openings of autumn formation. Polar bears form clusters near the island. Wrangel, beluga whales - to the east and northeast of Cape Navarin, walruses - to the south of it. The stability of winter spatial groups of walrus and polar bears in the Arctic Ocean, which annually demonstrated similar levels of abundance, has been established. Winter aerial surveys showed that beluga whales and humpback whales are not found north of the Bering Strait, and polar bears are almost never found outside the Arctic Basin.

Data on the seasonal development of 78 species of perennial plants in the Western Siberia forest-steppe due to changes in the regional climate are summarized over a 20-year period 1996-2015. It is shown that the meteorological indicators of the warm season in Novosibirsk have undergone noticeable changes: the average daily air temperature has increased by 0.16 °C, the growing season has extended by 12 days, and the period of active vegetation of plants at temperatures above 10 °C - by 8 days. Correlations of the dates of regrowth and flowering in perennials with the date of snowfall, the dates when the average daily air temperatures exceed 5 °C and 10 °C, and the sums of these temperatures were revealed. Using linear phenological trends, a delay within 2-6 days of the spring regrowth and an advance in the flowering by 2-10 days, except for early summer species, were established. A reduction of the prefloral period duration from 5 to 24 days indicated an acceleration in the rate of seasonal development in perennials against the background of the identified meteorological trends. The change in the duration of vegetation period was significant in spring-summer-fall green species and spring-summer-winter green species - 10 and 12 days, respectively. Low values of the coefficient of determination for most of the trends R ² < 0.06 showed changes in the phenology were mainly due to interannual variability.

The results of the study of biological and ecological features of the invasive species Elaeagnus angustifolia L. in the territory of the South Urals are given. The species is actively naturalized mainly in river floodplains and around other reservoirs. It is included in the Black Book of flora of Central Russia, Siberia, “black lists” of the Middle Volga region, Voronezh, Orenburg and other regions. The total number in the investigated coenopulations is estimated at 18-20 thousand individuals. The species is naturalized in various types of phytocoenoses - from steeped meadows to halophytic communities. Most of the investigated coenopulations are located in an arid climate, with little precipitation. The northernmost coenopopulations are in more favorable natural and climatic conditions. DCA-ordination of communities revealed leading environmental factors: continental climate, humidification, soil acidity, rich soils with nitrogen, moisture variability. Individuals of E. angustifolia vary in height from 2 to 8 m. Tall plants are noted mainly on unsalted habitats with sufficient humidification. Lower plants are found in saline or dry habitats. The study of reproductive biology revealed that the greatest indicators for the parameters of fruits are observed in the coenopulations Aslykul, Izobilnoye, Sol-Iletsk, the minimum - in the coenopulation Tatar Kargala. Regression analysis of the dependence of the bone fraction on the fetal mass shows that with an increase in fetal mass, a decrease in the bone fraction is observed. The naturalization of E. angustifolia in river floodplains negatively affects the growth, development and resumption of native forest-forming species, which leads to irreversible consequences of the degeneration of floodplain forests.

The investigation of belowground plant production and its determining factors is critical for better understanding carbon turnover in the biosphere. The measurement of fine root production is a methodical and difficult task. To reveal factors determining fine root production in mountain ecosystems, we introduced a new modification of ingrowth method with the use of filter balls (tea strainers). We studied root production in 16 communities from upper forest to subnival belts in the range of 2184-3069 m a. s. l. in the Teberda Reserve, Northwestern Caucasus, Russia. The filter balls were filled with sifted soil (without roots or stones) and buried in the soil 7-8 cm deep. The mass of root ingrowth was measured after two months of incubation under natural conditions. Mixed-effect models were applied to test the relationships between root mass, elevation, soil moisture, organic matter content, and pH. The highest root production was observed in an alpine snowbed (247 mg per filter ball in 60 days), the lowest was in forest and subnival communities (3-20 mg per filter ball in 60 days). The communities with woody dominants had lower production than herb communities. It increased with soil moisture, which was the most important factor. In herb communities the production of roots tended to decrease with the elevation. Soil organic matter as a separate factor had a positive relationship with root production in herb communities. There were no links between root ingrowth and soil pH. The method introduced presently both allows for the comparison of plant communities by their root production and reveals factors determining it.

The morphological and physiological biochemical features of calciphytes Hedysarum grandiflorum Pall. and Hedysarum gmelinii Ledeb are investigated. Plants H . gmelinii grown on a more moisturized and saline soil substrate. The leaf parameters of plants H . grandiflorum were characterized by a greater thickness, an area and contained significantly more water compared to the leaves of H . gmelinii . The leaf mass per unit area of H . gmelinii is 1.5 times higher than that of H . grandiflorum . Pigment foundation of H . grandiflorum is more enriched with chlorophylls. The level of lipid peroxidation in H . grandiflorum plant cells lower more than twice compare with H . gmelinii . The activity of enzymes catalase, peroxidase, polyphenolxidase on the contrary it was higher in H . grandiflorum . In addition, H . grandiflorum leaf lipids were distinguished by a greater saturation of fatty acids (SFA) (46.0 % of the amount of SFA) than H . gmelinii (31.5 %), but the concentration of α-linolenic acid in the leaves of H . gmelinii 1.5 times higher than H . grandiflorum . It was concluded that the existence of calciphyte plants in peculiar soil-climatic conditions imposes specific morphological and physiological and biochemical features even among closely related species H . grandiflorum and H . gmelinii .

The results of a seven-year study of two populations of the rare orchid Cypripedium calceolus L. located in different ecotopes (in the forest and in the swamp) on the territory of the Komi Republic are presented. It was revealed that the size of the shoots of this species is influenced by the weather conditions of both the current and previous growing seasons, while the specifics of the action of weather factors depending on the growing conditions are noted. The number of generative shoots in the studied populations is positively associated with the temperature and humidity of August of the previous growing season, and frosts have an additional effect on their number. The number of shoots in different growing conditions during the study period changed synchronously and was positively associated (as well as the number of juvenile plants) with the weather (temperature and precipitation) at the beginning of the growing season. At the same time, the population of C. calceolus , growing in different ecotopes, differed in a number of characteristics: the spatial placement of shoots, their size, the number of flowers per shoot, etc. This indicates that all population parameters are strongly influenced by the local conditions of the site. In a more shaded habitat (forest), the population of C. calceolus remained stable during the seven years of study, whereas in the swamp the population was more dynamic. There was an increase in its number and active seed renewal. Despite the different seed productivity of the fruit in the two populations, the actual seed productivity of the generative shoot was the same in the same years of research.

The assessment and reliable prediction of the productivity of grassland communities are largely determined by the approaches and methods used. The use of information on the species composition of the plant community and its functional structure in determining the primary production expands the possibilities of using modern information databases of geobotanical data. Selection of practically significant functional groups of species (graminoids, motley grasses, legumes) in composition of grassland communities of hayfields and pastures and determination of dominant species allows to include indicators of biodiversity in the procedure of agricultural lands productivity estimation. The experience in predicting the amount of aboveground phytomass of grassland ecosystems using the data on the functional composition and projective cover of species is discussed. The conducted cluster analysis confirms the assumption of the relationship between community biodiversity and its productivity. Based on the main provisions of the dominance hypothesis, by building a statistical linear model, the possibility of predicting the value of aboveground biomass from the data on the species composition of communities and the abundance of the dominant functional groups of plants, which act as universal evaluation criteria, was tested. The predictive statistical model is constructed on the basis of processing of the experimental data received from 32 sample geobotanical areas. The model shows the relationship between the value of the predicted biomass for the community and the abundance of the main functional groups of plants, the way they are used and the result of assigning community to the classification categories of the EVC and EUNIS systems. The applied classifications, based on species lists and indicators of the projective cover of species, bring a component of biodiversity in the further evaluation of community productivity. The use of the developed linear regression model makes it possible to estimate the productivity of grassland communities similar in species composition and belonging to the same classification categories with a sufficiently high degree of reliability without direct collection of data on the produced biomass. The model makes it possible to take into account the contribution of plant species composition to the provision of productive ecosystem services, providing the development of an accessible technique for their evaluation.

According to the results of bird counts carried out in 140 habitats over 12 years, in the period from 1982 to 2002 drawn up hierarchical classification and a structural graph of the similarity of ornithocomplexes in the plain southwestern part of Western Siberia and Northern Kazakhstan have been compiled. The hierarchical classification contains 10 types of bird populations. The similarity graph is built at the level of types and is represented by three rows (trends). One row consists of bird complexes of residential and recreational areas, the second from wetlands and the third from forest, forest-field and steppe habitats. The given characteristics of taxa of classifications contain information on the three most numerous bird species (leaders in abundance), their share in the community, population density, and also on the background species richness. Based on the assessment of the degree of coincidence of the similarity of bird communities and environmental factors, a hierarchy of the impact of the main anthropogenic and natural factors determining the formation of the bird population has been established.

N the northern spurs of the Manchurian-Korean Mountains (Primorsky Territory), an assembly of dung beetles from sheep dung was studied. Data on the species composition, population dynamics, number and biomass of dung beetles are presented. Comparison of assemblages of dung beetles of the inhabitants of sheep dung of the northern spurs of the Manchurian-Korean Mountains and the South Sikhote-Alin Mountains shows that despite the fact that both groups were formed on the base of one local fauna and have the same number of species, but the taxonomic structure and dynamic (seasonal) aspects are quite different. Differences in the species composition and composition of trophodynamic groups are due to the peculiarities of the geographic location, different weather and climatic conditions, grazing regime and differences in the composition of grazed animals, historical factors of the formation and dynamics of beetle assemblages. Weather conditions, as a factor influencing the rehydration of sheep droppings, determines the dynamic processes in assemblages and limits the penetration of certain species into the Sikhote-Alin Mountain system. A small size of sheep excrements, which are both trophic and topical resources, determines a high transformation rate of the substrate and the distribution of species according to a hypothesis of niche interception. The overlapping of niches in species from the same trophodynamic groups leads to a shift in the timing of the imaginal activity of certain species

We present the results of study on the number of indicator bacterial groups of the nitrogen cycle in plankton and epilithon of the littoral zone Lake Baikal in the spring and autumn periods from 2017 to 2019. The number of ammonifying bacteria (AB) in the lake waters varied from 25 to 6.0 × 10⁵ cells/ml; in epilithic biofilms - from 3.5 × 10³ to 9.5 × 10⁶ cells/cm². The stations subject to anthropogenic impact showed a high number of AB as evidence of active mineralization of nitrogen-containing organic compounds. The maximum number of AB in the water column and the biofilms from stony substrates was detected in June 2017 in the water area of the Severobaikalsk town. The average annual number of AB in the water column was (5.0 ± 2.8) × 10² cells/ml in June and (6.0 ± 1.3) × 10² cells/ml in September. In epilithic biofilms, it was an order of magnitude lower in June than in September, (3.4 ± 1.2) × 10⁴ cells/cm² and (2.6 ± 1.4) × 10⁵ cells/cm², respectively. The number of denitrifying bacteria (DB) in water varied from 0 to 60 cells/ml; in epilithic biofilms - from 6 to 2.5 × 10³ cells/cm². Throughout the study period, the highest number of DB in epilithon was detected in June at the station near Elokhin Cape. The average annual number of DB in the water column was 13 ± 4 cells/ml in June and 7 ± 6 cells/ml in September; in epilithic biofilms - (7.9 ± 2.4) × 10² cells/cm² in June and (4.8 ± 0.5) × 10² cells/cm² in September. The number of planktonic AMB positively correlates with the concentration of ammonium ions; the number of DB directly depends on the nitrate concentration and inversely depends on nitrites at some stations.

To reveal changes in plant mineral nutrition causing leaves’ chlorosis and parthenocarpy in the blue honeysuckle plants of Siberian origin, grown on plantations in Heilongjiang Province, China, we compared macro- and trace elements’ composition in two counties in China and two districts in the south of the West Siberian plain. It was found that massive leaves’ chlorosis and dying-off, as well as hormonal changes resulting in parthenocarpal fruits, may be associated with soil acidity (рН_KCl 4.0-4.5) on some of the study sites in the Heilongjiang Province, as such high acidity increased plant available Al, Fe and Mn concentrations to phytotoxic levels. The blue honeysuckle plants grown on such study sites had specific patterns of Al, Fe, Mn, Cu and Zn distribution throughout their organs, as well as accumulation of toxic concentrations of Al, Fe, Mn in leaves, resulting in aberrant P/Al, Ca/Al, Mg/Al, P/Fe, P/Mn, Cu/Fe and Cu/Mn ratios, which are vitally important for plants.

Data on the state of stands and undergrowth of the main forest-forming species at the Karadag Nature Reserve in oak forests of downy oak (Quercus pubescens) and sessile oak (Q. petraea) under conditions of super-high density of European roe deer (Capreolus capreolus) are presented. The exponential growth in number of roe deer in the reserve, which has been observed since its creation (1979), led to an increase in its number by 2016 to 750 individuals and a density of up to 437 individuals per 1000 ha, which is 10 times higher than the norm. At the same time the level of damaged sessile oak undergrowth increased from 7.6 to 88.9 %, and downy oak - from 8.4 to 83.7 %. A decrease to an absolute minimum in number of mid and complete absence of big undergrowth of both sessile oak and pubescent oak took place. Alignment of tree species in abundance (estimated by the Berger-Parker index) is 1.20 for sessile oak stands and 1.18 for downy oak stands, and undergrowth in these stands is 3.0 and 1.6 respectively. At the Primorskoye Forestry located next to the reserve, relatively favorable in terms of the density of roe deer (37 individuals per 1 thousand ha), damage to the undergrowth of the main species was 5.5 % in sessile oak groves and 7.2 % in downy oak groves. Alignment of tree species in oak forests at the Primorskoye Forestry in abundance is 1.25 for sessile oak and 1.54 for downy oak, and for undergrowth - 2.15 and 2.11 respectively. Being based on the totality of the obtained data it was concluded that even under conditions of a super-high density of ungulates oak forests of the Karadag Reserve retain the possibility of renewal due to an increase in the density of small undergrowth (sessile oak groves) and alignment of undergrowth (downy oak groves). Regarding to the renewal of the main species the excessive number of roe deer in the reserve plays a negative role, and respectively biodiversity in terms of the alignment of tree species undergrowth in terms of abundance it plays a positive role.

Results of studying kerosene combustion in a pseudoshock with varied temperature and velocity at the scramjet combustor model are presented. Thermodynamic estimates show that either a supersonic or transonic flow can be retained over the combustor duct at parameters corresponding to the Mach number at the engine entrance М₀ » 4.5. The possibility of the pseudoshock regime in the constant-section part of the combustor is experimentally studied in the case where the Mach number behind the inlet (at the combustor entrance) is М _c > 1. Conditions of initiation and evolution of this combustion mode under a pulsed-periodic action on the flow are determined.

The Hedvall effect was implemented in self-propagating high-temperature synthesis (SHS) in two low-energy compositions TiNi + 1.1C and Ni₃Al + 1.2Si using preliminary mechanical activation (MA) in an energy-intensive planetary ball mill. The dependences of the initiation temperature and the maximum reaction temperature on the MA time were obtained. The MA modes providing the solid-state mode of the self-propagating reaction were determined. The results of X-ray phase and electron microscopic examination of MA and SHS products are given.

A technique for obtaining large burning monolithic titanium particles is described. The combustion of particles with a diameter of 120 ÷ 540 mm in free fall in air at atmospheric pressure is investigated. The burning time and the characteristic time of the beginning and end of fragmentation as a function of particle diameter are determined by processing video recordings of combustion of more than 250 particles. Two fragmentation modes are described. It is found that their occurrence depends on the diameter of the burning particle. The boundary particle size separating the modes is determined. It is shown that the fragmentation regularities and characteristic times for titanium agglomerates and monolithic particles of the indicated sizes differ slightly.

This paper describes the effect of preliminary mechanical activation (MA) and Ti content on a maximum temperature, a maximum burning rate, the size of composite particles, the yield of a mixture after MA, the elongation of samples during combustion, and the phase composition and morphology of combustion products in the Ni-Ti-Al system. The preliminary MA of a Ni + Al + Ti mixture expands the limit of titanium content at which samples can burn without preheating, from 17 to 59 % (by weight). Mechanical activation reduces the number of phases in the products and increases the burning rate, while the maximum synthesis temperature decreases. An increase in the Ti content in the Ni + Al + Ti mixture reduces the rate and maximum combustion temperature of both the initial and MA mixture. In addition, as the titanium content increases, the average size of composite particles decreases and the yield of the activated mixture becomes larger. During the combustion of MA mixtures with a high (24 ÷ 52 %) titanium content, the Ti₂Ni phase and the Ni₂TiAl Heusler phase predominate in the products, and traces of melting are visually observed. In the activated Ni + Al + Ti mixture, the Ti content at which the content of the Heusler phase in the combustion products is maximum is revealed. For most of the observed dependences, an explanation is proposed.

Combustion during self-propagating high-temperature synthesis of Ti + 1.7B reaction tapes obtained by rolling from a powder mixture is experimentally investigated. Dependences between the combustion wave propagation velocity in the reaction tapes and the applied pressure are revealed. It is shown that the burning rate of the tapes weakly depends on the compression pressure within 0.001 ÷ 4 MPa. At a compression pressure above 0.5 MPa, unreacted regions appear during the combustion of the tapes. The limiting pressure at which the combustion stops is determined as 12 MPa.

Detonation nanodiamonds (DND) represent a unique material combining the properties of a rather passive diamond core with an active carbon shell. The effect of disaggregated DND (T-DND) and detonation carbon (diamond batch mixture (T-DBM)) obtained in an explosion of tetryl (2,4,6-trinitro-N-methyl-N-nitroaniline) and preliminary deposited onto ammonium perchlorate granules in the process of its crystallization on the burning rate of a paste-like propellant is studied. T-DND is preliminary cured at 430 °C for two hours. The method used in the present study is chemical deposition (forced crystallization) of ammonium perchlorate from a saturated aqueous solution also containing T-DND or T-DBM by isopropanol in the ratio of 1 : 2. The burning rates of compositions are determined as functions of pressure in the range up to 1 200 atm. It is demonstrated that the use of detonation nanodiamonds and diamond batch mixture leads to an increase in the propellant burning rate approximately by 26 and 15 %, respectively, while the temperature of combustion products decreases approximately by »240 °C at 100 atm.

This paper addresses the effect of oxidizer particle orientation on the burning rate of ammonium-perchlorate-based heterogeneous solid propellants. Mesoscale numerical simulations are conducted assuming that oxidizer particles are ellipsoidal and have different orientations with respect to the combustion direction. The particle orientation is found to produce a significant effect on the burning rate, up to 5 ÷ 10 % depending on the particle aspect ratio or particle loading. Particles aligned normal to the combustion surface are found to burn faster than those aligned parallel to this surface. This strong impact of the orientation can help explain the well-known hump effect in solid propulsion.

This paper describes the results of a numerical study pertaining to the interruption of detonation wave propagation in air-gas mixtures of unitary fuel as a layer of inhomogeneous inert particles. It is shown that the layer diameter, layer length, and the inhomogeneity of inert particles affect this process. It is revealed that, if the total mass of the mixture is fixed, a layer with a linearly decreasing concentration of inert particles attenuates detonation waves much better than that a linearly increasing and uniform concentration of inert particles.

Co-C nanoparticles are synthesized via the detonation of benzene and oxygen with cobalt(III) acetylacetonate as a precursor, and the influence of heat treatment on their physical performances is explored. The results indicate that the crystallinity and degree of graphitization of Co-C nanoparticles are dramatically improved after heat treatment, and the impedance matching degree also increases significantly. The wave absorption property is enhanced by more than six times, and the minimum reflection loss is -17.5 dB at 16.98 GHz. The impedance mismatching is the main reason for the poor wave absorption of original Co-C nanoparticles. The temperature plays an important role in the impedance matching degree and wave absorption performance, and a heat-treated process can be a useful way to solve impedance mismatching of Co-C nanoparticles prepared by gaseous detonation.

Experimental results on the parameters of detonation process formation in phlegmatized HMX as functions of the velocity and size of spherical impactors are reported. Data on the threshold velocity of the impactor resulting in detonation initiation and on the length of the pre-detonation segment in the velocity range from 882 to 1 333 m/s are obtained. The results are compared with available experimental data on the length of the pre-detonation segment for plane shock waves. The radio interferometry method of registration of the evolution of the explosion process initiated by the impactor is demonstrated to be fairly informative.

The detonation velocity and propulsive capability of an aluminized emulsion explosive sensitized by Expancel polymer microballoons was measured. The density of the investigated explosive compositions was 0.2 ÷ 1.4 g/cm³, and the mass content of aluminum powder was 0 ÷ 0.29. The propulsive capability was measured using the cylinder expansion test.

In this study, a new model based on a single equation is developed for estimating the detonation velocity of any organic/inorganic explosives. The new model is based on adaptation of feasible rules, oxygen balance, and heat of reaction for identification of detonation products. The final results of the new model for the detonation velocity are in good agreement with available experimental values, as well as with the Becker-Kistiakowsky-Wilson model values of the EXPLO5 software and with results obtained by other methods. The results reveal the minimum relative deviation percentage error for all the organic, inorganic, and mixed explosives as compared to other models. Therefore, the newly developed simple model and rules will be useful for a scientist/chemist to predict the detonation velocity of any new explosives without depending upon expensive computer codes.

The brightness temperature of polymethyl methacrylate loaded by a shock wave reflected from a transparent LiF or sapphire window was measured by a pyrometric method. The pressure range in the primary wave was 20 ÷ 40 GPa, and that in the reflected wave was 30 ÷ 78 GPa. At the intensity of the primary shock wave in the range of low pressures (19.2 ÷ 20.8 GPa), the temperature values in the reflected wave lie on a single Hugoniot within the experimental error, as opposed to what might be expected from the gas-dynamic calculation for the case of loading by two shock waves. As the primary shock wave pressure increases to 38 ÷ 41 GPa, the reflected wave temperature ((2.4 ÷ 2.6) · 10³ K) becomes smaller than on the single Hugoniot (3.1 · 10³ K), but remain larger than those calculated by the equation of state (2.3 · 10³ K) under the assumption that the composition of polymethyl methacrylate is inert. It is concluded that this form of the temperature dependence is due to the depolymerization and subsequent decomposition of polymethyl methacrylate.

This paper presents the results of sound velocity measurements performed in natural uranium during the high-rate deformation of sound in α- and γ-phase regions, as well as in the melting region at the shock front. The processes are recorded using the manganin sensor method (range 20 ÷ 110 GPa) and the indicator method (range 70 ÷ 260 GPa). In the region of the solid uranium phase, changes in Poisson's ratio, Young's modulus, bulk modulus, and shear modulus along the uranium shock adiabat are determined.

The influence of controlled perturbations on the buckling of conical liners during their explosive compression is under study. In this case, there is folding on the inner surface of the liners, oriented along the generatrix of the cone. It is revealed that, as the Reynolds number increases, so does the number of fold, while the geometric dimensions of experimental devices remain the same. It is shown that scratching on the inner surface of the cladding makes it possible to control its buckling process.

The issues related to efficiency of the use of the recreation potential and the regulation of the recreational load on the ter ritory of the nature parks of Volgograd oblast in established ecological routes are examined. For the analysis the Shcherbakovskii, Donskoi and El’tonskii Nature Parks are used their location on the territory of the region makes it possible to cover the entire spectrum of zonal steppe landscapes, including their different variations. The information basis for the analysis included data on the technical parameters of the routes implemented by selected nature parks and on congestion of the routes during the three seasons in the period 2015-2017. Estimates were made of the physical current capacity, maximum real capacity and actual capacity of the tourist routes and ecological trails. Our calculation implies a sequential updating of the value of effective current capacity on the basis of corrective parameters taking into account the actual conditions for the functioning of specially protected natural areas at the present time. Results of calculations show a consistent decrease of the values of recreation capacity in the «physical current capacity - maximum real capacity - actual capacity» line for most routes. The resulting pattern indicates a low level of load in implementing the route-based recreation and allows to suggest measures to improve its efficiency. The causes for the low efficiency in the use of the recreation potential of ecological and tourist routes for the nature parks of Volgograd oblast are identified.

A historical background of the hydrological role of forests abroad and in Russia is presented. Attention is focused on the significance of solid precipitation for the Ural in the formation of the channel flow and groundwater recharge. Forest is considered as a regulated landscape influencing the hydrological regime of the territory. The study as carried out in the southern-taiga for est district of the Middle Ural low-mountain province of the Ural mountain forest region. An analysis is made of snow storage under the forest canopy for a long-term period having regard to the fluctuations in winter weather conditions. Detailed forest inventory characteristics of forest stands on snow survey profiles are presented. Long-term series of observations were analyzed using principal component analysis. Data on the snow depth on open sites and under the forest canopy of a different composition are given. The leading formation factors for the snow layer and water storage in it within forest catchments are determined. It is established that in the Ural the snow depth in the forest is determined by the degree of closeness, the age of the forest stand and average temperatures of the winter season, and snow storage is primarily associated with the meteorological factors and slope exposure and less with the age and degree of closeness of the forest stand. Data on the dynamics of snow storage in forest stands of the same age and the same degree of closeness are presented. It is established that water storage in the snow can decrease with the increasing contribution of dark coniferous species; in this case, the leading formation factor for water storage in the snow is the contribution from coniferous species in the forest stand composition. The range of influence of the species composition of the forest stand depends largely on the weather conditions of the winter season.

This article presents the results of 30 years (1988-2017) observations of wind-snow interaction processes on the territory of Tomsk oblast. Based on long-term landscape-route snow surveys, it has been established that on the study territory every year there occur wind-driven snow processes similar to aeolian processes in the mechanism of action. An analysis is made of their influence on the soil transformation within the agrolandscapes in the south of Western Siberia. The influence of the various processes and properties of landscape components on snow accumulation conditions in small river basins of the Tom-Yaya in terfluve is outlined. For a detailed study into the wind-driven snow processes within the study territory, we used the key area located within the Basandika small river basin, with the type of nature management characteristic for the southern regions of Western Siberia. The average annual values of temperatures and precipitation amounts were calculated for the study territory, and their trends were determined. An analysis was made of changes in snow cover characteristics: the snow thickness, start of formation and duration. The anti-deflation resistance of soils was calculated and critical wind velocities leading to winter defla tion were identified. The wind regime parameters were determined for a cold period of a year: the frequency of moderate and strong wind velocities, their cyclicity and the activity of wind transport. Accumulative and deflationary aeolian relief-formations in a cold period of a year have been measured and described. Winter deflation of arable soils is assessed on the basis of long-term field observations, and the amount of aeolian snowdrift in the snow thickness is determined. It is concluded that the most intense development of deflation centers and the formation of aeolian ripples on the snow surface are observed in early spring during snowmelt. An analysis was made of the snow samples to reveal a high level of accumulation of soil particles on the snow surface. A predominance of dust fractions was observed in determining the composition of aeolian snowdrift.

We calculated the water balance and investigated the mineralization of water in closed Lake Chany, the largest lake in Western Siberia in terms of its water area and of great ecological and fisheries importance. The most important natural charac teristic of the lake is the cyclic fluctuation of the water level caused by the variability in the overall humidity of the Ob-Irtysh interfluve. The water level regime of Lake Chany is the main natural factor influencing its water-ecological state. Changes in water level are determined by the ratio between the inflow and discharge in its water balance. The modern water balance of Lake Chany (after the separation of the Yudinskii reach) was calculated for hydrological years, and the previously calculated values of its components were refined using a new digital elevation model. It was found that the most significant influence on the water level fluctuation comes from changes in the discharge of the Kargat and Chulym rivers feeding the lake, which is confirmed by a high correlation coefficient between the river inflow and the level increment. Comparison of the curve of changes of the average annual level of Lake Chany and the differential integral curve of the total annual flow of the Kargat and Chulym rivers shows that the main phases of fluctuations in the water level in the lake and the river inflow coincide. The values of mineralization of the lake water changes with fluctuations in water storage. Results of investigations made in 2002 and 2004 were used in carrying out the zoning of the lake water area according to the mineralization of water. The heterogeneity of water salinity is explained by the morphology of its basin without outflow, a low water exchange between different parts of the lake, and by the desalinating effect of the waters of its feeding rivers.

The spatial distribution of total water vapor content over the Yamal Peninsula and adjacent territories was analyzed using data of four-year-long measurements from the European ENVISAT satellite during warm periods of the year (June-August). Special attention was given to water vapor variations at the transition from little to abundant water-bearing areas of the underly ing surface. It was found that for the five selected sites located in a dry tundra and in large water bodies the logarithmic rather than Gaussian form of the distribution functions of total water vapor content turned out to be typical according to the number of its measurements. Each function has at least two modes. The parameters of these modes were calculated and presented, and they are necessary for simulation of climatic conditions in the northern territories. Geometric mean values of total water vapor content over the Gulfs of Gydan and Baidaratsk, and especially over the Gulf of Ob, can be by a factor of 1.5 larger than those for the less water-abundant areas of tundra and have clear boundaries coincident with geographical contours of the water bodies. It is most likely that these boundaries exist at insignificant speeds of surface winds, which is indicative of weak turbulent mixing of the lower air layers. This conclusion is confirmed by results from processing published data of ground-based and satellite observations. For the five sites they were used to calculate and construct the wind roses for all five sections in the same time intervals when the satellite measurements of water vapor content were carried out. Wind rose analysis shows that the average velocity of predomi nantly N and NW winds on all the selected sites at a height of 10 m above the underlying surface are 5-6 m/s with a standard deviation of 1.5 m/s. Additional data are presented on the form of the distribution function of various parameters in other natural environments (water bodies and vegetation) which give support to what has been said above about water vapor.

We substantiate the use of the previously developed methods to classify sections of the largest river (Lena) from the types of channel processes and special aspects of their management, i. e. water resource use, exploitation of the river as the water transport way, development of riverine areas and construction of river crossings for service lines. For assessing the complexity of river channel reconfiguration and implementing regulatory measures we use certain indicators of channel stability, the channel patten, river runoff, conditions of effective discharge, composition of bed-material load, occurrence of riffles and characteristics of their regime. It is shown that the indicator of complexity of channel processes management is represented by the amount of channel dredging performed to ensure normal navigation conditions. On the Lena river (from the Osetrovo port to the estuary) there are 10 reaches which differ both in the features and the degree of complexity of channel processes and, accordingly, in the conditions for their management. The study identified the most difficult (for channel management) sections; for the broad floodplain, unstable and compound braided channel we determined the main water management and water transport problems associated with channel processes.

The state and the prospects of implementation of major investment projects combined into the Eastern Gas Program have been analyzed. The terms of realization, the state of resources and the state of gas transportation system under the projects form ing part of them are considered. It is shown that only one (Sakhalin) of four gas production centers foreseen in the program has an adequate infrastructure; the unified gas transportation system has not been established, and the gas processing industry has received insufficient development. It has been determined that the capacity of the pipeline makes up 70 % of the total production volume and this is the factor limiting the development of the gas production and processing industry in the regions. The reasons for a change of the terms and conditions of the development of the projects of the Eastern Gas Program have been investigated. It is shown that the discrepancy in key goals and the actual state of gas industry in the eastern regions of the country is explained by the changing situation in the key gas markets, which determines the final economic efficiency of the projects, the lack of the solution to long-term demand problems and stable sources of financing. The prospects of the development of the projects of the Gas Program and the risks of implementation for the Russian side have also been investigated. The article describes a dependence of the implementation of separate projects on the possibility of signing efficient international contracts with the countries of the Asia-Pacific region and on the success of the strategy of formation of new export goods niches based on the in-depth processing of hydrocarbon raw materials. The consequences of creating the full-scale gas industry in Eastern Russia have been analyzed. It has been determined that the projects within the Program with a focus on the formation of the national export income have been implemented. It is shown that the projects within the Program do not ensure an accelerated development of the Eastern regions of the country because of the lack linkages between the projects and other branches of regional economy. Furthermore, the regions do not accumulate financial resources from the project implementation.

Socio-economic maps are essential for identification and system analysis of sectoral and territorial imbalances, ensuring the effective organization of productive forces, planning and forecasting of socio-economic development of the territory. This paper presents the authors’ experience in creating and interpreting socio-economic maps in national and regional atlases, ana lyzes current trends in the development of socio-economic mapping of the eastern regions of the country, which have their own characteristic features (a high sectoral and territorial differentiation, weak integration ties, underdeveloped infrastructure and innovation, etc.). Special attention is paid to the creation and practical use of the general economic map as a universal source of spatial information. In this context, an attempt is made to modify the technique of compiling the general economic map. The authors’ scientific developments that have found their practical implementation are presented. We defined the main problems and prospects of further developing socio-economic mapping related to future geoinformation mapping. Results of summarizing and re-interpreting a huge body of theoretical and practical material suggest that socio-economic mapping is in the next critical stage of its development and requires significant changes in many areas. Therefore, this dictates a need for a new view of the concep tual framework and methodology for compilation and use of socio-economic maps, and for switchover to the creation of complex maps (animation, three-dimensional, assessment-forecast and other maps.

The problem of constructing a statistical predictive model and the related problem of selecting predictors for the forecasted variable are considered. This study is based on using data on the interannual variability in average discharge of the Ob in the hydrometric section of Barnaul during the flood period and on hydrometeorological characteristics having a potential influence on it. It is argued that the result from selecting predictors for the predictive model depends not only on the data used but also on the method employed in solving the problem. Such a method is determined by the mathematical operator used to approximate the simulated dependence, the optimality criterion of the model and the algorithm for selecting predictors. To study the influence of the modeling method on its result, a number of computer experiments were carried out, and each of them used different meth ods to find the best combination of predictors. It is shown that the best solution on the training sample is not always confirmed on independent data. To improve the sustainability of the simulation results, it is recommended that the criteria for selecting the optimal model should be used, which include assessments of its reliability. Use and comparison of different methods of construct ing models made it possible to identify the main predictors which explain most of the variance of the forecasted discharge. They are determined primarily by data on the object and have a physical interpretation. Their selection is less dependent on the method used to construct the model. The highest effectiveness was shown by the method of constructing the predictive model as an ensemble of partial models, each of which uses a limited number of non-intersecting predictors. Retaining the sustainability of the simulation result, make it possible to take into account, along with the main predictors, also the influence of secondary factors and, hence, to improve somewhat the quality of the predictive technique being developed.

Use of the basin approach and other modern research methods (information-logical analysis, and geomodeling) helped to reveal the interaction and special features of the mutual location of geosystems of altitudinal belts and river catchments which form the characteristic features in the differentiation of vegetation and soil cover in mountain conditions. It is shown that the landscape pattern and morphometric characteristics of river basins indicate different processes of destruction of the mountain massif in the western and eastern parts of the Basegi Ridge. It was found that the asymmetry in the slopes of the ridge and the associated hydrothermal conditions lead to a differentiation in the structural organization of the basins. This study determined the degree of dependence of the plant community and the soil type on the slope steepness and exposure, the absolute elevation and structural elements of the catchments of small rivers. According to an enhancement in the degree of influence on the growth conditions of plant communities, the topographic features under study form a series: slope exposure < elements of river ba sins < slope steepness < height above the sea level in meters. Specific conditions of vegetation and soils corresponding to the elements of the basin are determined. It is concluded that tundra and meadow vegetation is more informative. Based on the generalized spatial analysis, the cartographic model was developed for the soil cover of the Basegi Ridge. The elements of the catchments are characterized by different soil cover. A maximal diversity of plant communities and soil cover variegation on the slope surfaces of river basins is more clearly pronounced. Soil cover variegation implies a combination of zonal soils (Brown forest soils, Cambisols) of the mountain taiga and azonal soils (Gleezems (Gleysols) and peat soils (Histosols)). Hence, with the processes of basin formation predominating, the slopes show some “deformation” of the existing structure of altitudinal-vegetation belts. In watershed spaces, above the energy zones (catchment funnels), the influence of basin formation is weakening and the altitudinal zonation-associated differentiation is enhanced.

Presented are the results from investigating the atmospheric self-purification capacity over the cities of Irkutsk, Beijing and Ulaanbaatar for the summer and winter seasons of 2017-2018. The meteorological potential of the atmosphere (MPA) was used as the criterion for assessing the atmospheric self-purification. It is shown that in the summer season of 2017 the favorable meteorological conditions for the dispersion of air pollutants were dominant over the territory of Irkutsk and Ulaanbaatar. In the summer, MPA was 0,99 and 0,78 in Irkutsk and in Ulaanbaatar, respectively. MPA varied from 2,14 to 4,66 in Beijing in the summer. For the winter months in the three cities, MPA > 1, which indicates an accumulation of pollutants in the atmosphere for that season. In Ulaanbaatar there were unfavorable conditions for self-purification: the maximum MPA index (9.5) was observed in December. The largest contribution to impairment of the atmospheric diffusing capacity over Ulaanbaatar in the wintertime was made by wind velocities of 0-1 m/s. It was found that the maximum accumulation of pollutants in the atmosphere over Beijing occurs in the winter. MPA varied from 15,0 in February to 19,03 in December, averaging 16.68. Fogs made the largest contribution to the unfavorable meteorological conditions of Beijing in December-February. The characteristic properties of the atmospheric circulation, wind regime, fog and atmospheric precipitation were responsible for MPA of Irkutsk, Ulaanbaatar and Beijing for the period under consideration.