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This paper describes a problem of steady-state creep of a long narrow rectangular membrane in the case of a linear dependence between the transverse pressure and time. The membrane is located inside a tall long rigid matrix with a rectangular cross section, the ratio of the height to half the width is greater than unity. A power-series relationship between the stress intensities and creep strain rates of the membrane is used. Two variants of contact conditions for the membrane and the matrix are considered: ideal sliding and adhesion. The analysis of the problem is carried out until the time at which the membrane is almost completely adjacent to the matrix walls. It is shown that, if the relative height of the membrane is smaller than a certain value, then the creep duration of the membrane until the moment at which it almost completely adjoins the matrix walls is shorter in the case of ideal sliding than in the case of adhesion, and vice versa. An explanation of this effect is provided.

Mechanical and tribological properties of polyimide-based three-species antifriction composites filled with polytetrafluoroethylene and milled carbon fibers with a mass fraction of 5-15% are studied. It is shown that the elasticity modulus can be almost doubled by adding milled carbon fibers. The study of tribological characteristics shows that the wear of surfaces can be reduced by using the above-mentioned complex filler by a factor of 265 in the case of metal-polymer tribocoupling and by a factor of 255 in the case of ceramic-polymer tribocoupling. Optimal compositions of the polyimide-based three-species solid lubricant composite to be used in the cases of metal-polymer and ceramic-polymer tribocoupling are determined by using an in-house computer algorithm.

Explosion chamber modification is proposed. It is intended for studying detonation and shock-wave processes using synchrotron radiation. Examples of explosive chamber designs that meet the necessary conditions are given. Numerical simulation is used to obtain a dependence between the degree of inhomogeneity of the stress state of an explosion chamber shell and the ratio of the shell radius to its thickness.

On the basis of high-precision astronomical ephemeris with a high spatial and temporal resolution, the insolation of the Earth at the upper boundary of the atmosphere was calculated for the period from 3000 BC through 2999 AD. The differences from the earlier calculations of insolation are associated with the initial astronomical data and new calculation algorithms. In our calculations of insolation, the time interval of 5999 years and the entire surface of the Earth are covered in detail. The Earth is not identified with a sphere, but is approximated by an ellipsoid. Previously, calculations of high-frequency variations in insolation were performed for individual parallels (in space), and in time for four or five separate points of the year (equinoxes, solstices and, sometimes, points with a geocentric longitude of 120 degrees). We have calculated insolation for the surface of latitudinal zones at 1° latitude and time intervals equal to 1/360 of the duration of a tropical year (approximately a day). Correlation analysis of the total mass balance of alpine glaciers (for the period from the balance years 1948/1949 to 2009/2010) with summer and winter insolation and summer, winter and annual insolation contrast of the northern hemisphere, which in a summarized forms (by regions of heat source and sink) reflects long-term changes in the meridional insolation gradient. It has been determined that the long-term variability in the total mass balance of alpine glaciers on average (for glaciers covered by balance observations) is accounted for by the trend by 94.3 %. The trend in the reduction of alpine glaciers by an average of 90.6 % is determined by the annual insolation contrast, which reflects an increase in the meridional heat transfer, determined by an increase in the meridional contrast of radiant energy (on the Earth’s surface, excluding the atmosphere). Based on the close correlations determined by using a regression model, a forecast of the total mass balance of glaciers up to 2050 AD was made, which indicates a catastrophic development of the degradation of the modern glaciation of the Alps.

The use diverse, multi-temporal satellite space information has become the main approach in investigating the current status of mountain glaciers. We have accumulated large archives of satellite images of snow-glacial systems on Earth with different spatial resolutions over the past 50 years. Together with the previously created topographic maps displaying glaciers, glacier catalogs, special maps and atlases of ice and snow, they give grounds to determine changes in areas, lengths, volumes, and altitude of glaciers during the current climate warming. In 1986, the World Glacier Monitoring Service (WGMS) was founded to monitor glacier fluctuations in different regions of the Earth. However, the number of observation sites is limited. The Global Ground Glacier Observing Network mainly includes those glaciers where we previously conducted ground-based studies of glacier front fluctuations, mass balance measurements, measurements of meteorological parameters, ice flow velocities, and ablation features. To identify regional differences, different altitude and plan locations, the influence of permafrost, and the background landscape environment requires data on a larger number of glaciers being analyzed. Therefore, groups of researchers from Irkutsk and Beijing, started to study the dynamics of glaciers in the inland regions of Eurasia within the framework of international projects. Several glaciers were selected in the mountains of the south of Eastern Siberia, the Mongolian Altai and the eastern part of the Tien Shan. We recorded current glacier fronts and their elevation marks. The lengths and areas of glaciers in the early 1970s and early 2000s and their current state were determined. In recent decades, some connections between the dynamics of glaciers and changes in meteorological parameters have been revealed.

The transformation of irrigated lands in the regions of Russia over a long period of time has been studied. It was found that from 1990 to 2018 the area of irrigated land in the country decreased from 6.2 to 4.7 million hectares. In some constituent entities of the Russian Federation, the land area decreased by a factor of 4-14, and in two of them it increased by 35-40 %. It was found that 735 thousand hectares of irrigated land (16 %) were not used in agricultural production in 2018, largely due to soil salinization and waterlogging, with only 3.7 % corresponding to the year 1990. It is concluded that it is necessary to quickly bring into production the unused irrigated lands in order to enhance food security and increase exports of food and agricultural raw materials. The transformation of the structure of irrigated agricultural land in Russia as a whole is less perceptible, whereas in some regions it is conspicuous. There is a need to increase the share of forage crops in irrigated crop rotations to improve soil fertility, and increase the production of forage and livestock products. It is shown that in recent decades in Russia there has been a steady trend in deterioration in the reclamation state of irrigated lands. A particularly unfavorable situation has developed in the Northwestern District. The area in which capital improvements are required to increase the technical level of irrigation systems has increased dramatically. The area of actually irrigated land progressively decreased from 4.9 million hectares in 1990 to 1.4 million hectares in 2016. On the other hand, drip irrigation systems are rapidly developing, which have shown high efficiency. It has been established that it is necessary to develop more widely the production of drip irrigation systems at domestic and joint ventures in Russian regions. Data on the beginning of the revival of the production of domestic sprinkling equipment, which is not inferior to foreign counterparts and is much cheaper, are presented.

A forecasting cartographic modeling of the direction and rate of transformation of the region’s landscape-zonal structure has been carried out according to one of the scenarios of global climate change. The methodology of predictive analytical calculations as an algorithm for operations with climatic niches of geo (eco-) systems is described. Regional mapping of focal and induction phytocoenological transformation of landscapes of various natural zones was performed by using the thermo-humid variant of regional warming. It is shown that the zonal component of the climatogenic transformation of geosystems is the primary object of regional landscape-ecological forecasting. On the forecast maps of the dominant focal transformation of landscapes, two dynamic characteristics are shown: 1) the prevailing tendency for a given type of landscape to move from its “own” natural zone (subzone) to another zonal subdivision, and 2) the general degree of interzonal phytocoenological transformations of landscapes of a given species. The secondary induction transformation of landscapes, associated with their transboundary interaction and determining the degree of displacement of landscape boundaries, actually manifests itself only for landscape neighbors of the first order, with a corresponding shift of landscape boundaries. A quantitative assessment of the influence of “generic barriers” characterizing the morphogenetic contrasts of the natural-territorial mosaic pattern on the system of landscape-zonal transitions is given. Fragments of forecast maps of focal and induction transformation of landscapes in the Volga river basin are presented. The processes of phytocoenotic transformations of the landscapes for the predicted periods of 2050, 2075 and 2100 are briefly described. In the western sector of the Volga basin, mass transgression of boreal vegetation into the subzone of deciduous forests and even into the middle forest-steppe is predicted. In the eastern, pre-Ural sector, on the contrary, the introduction of broad-leaved and forest-steppe communities in the boreal zone is expected.

Experimental investigations were made into the basicity-acidityindices (pH) and soil biochemical activity (SBA) in the industrial city of Ust’-Ilimsk in conditions of Eastern Siberia. A cartographic representation of the distribution of values of integral indicators of soils in the city is presented for the first time. The significance of the method of mapping urban soils experiencing urbanization and technogenesis is emphasized. The investigation was made by using the express method of determining the soil biochemical activity. In addition to this indicator, pH conditions of soils were identified. The study encompassed the main functional zones of two parts of Ust’-Ilimsk: the Old City (Levoberezhie) and the New City (Pravoberezhie). Of widespread occurrence on the territory are the neutral and weakly alkaline soils. The pH values vary from 7.4 to 7.8; in the control soils, they vary from 6.3 to 6.9. A significant area of the city (43.9 %) is occupied by weakly alkaline soils. The level of soil biochemical activity permitted us to categorize the soils as active and very active. The proportion of very active soils makes up 32.9 % of the total territory of the city. This indicates a trend of ecological regression, namely a loss of the biogenic element, nitrogen. The study revealed trends of a weak but positive dependence of SBA on pH. The coefficients of approximation are positive and vary, according to the zones of the city, from 0.2 to 0.5. The absolute and relative distribution of the areas with pH and SBA values is shown. A comparative analysis of data revealed a difference of the Ust’-Ilimsk soils from the soils in other cities of the Angara region.