bluuebunny/crossref_metadata_2025_split huggingface dataset:
Ecological-coenotic structure of the pine forest flora at the southern margin of the geographical range of Pinus sylvestris L
Authors: Kin N O , Senator S A 
Published: December 2020

Abstract
The ecological-coenotic structure of pine forest flora was compared at the southern margin of the geographical range of Pinus sylvestris. The Usmansky and Khrenovsky (Voronezh and Lipetsk regions), Krasnosamarsky and Buzuluksky (Samara and Orenburg regions) pine forests were investigated. The species diversity of vascular plants in the studied forests included also the alien and introduced species. The coenotic structure reflects the zonal location of the pine forests and their current state. The zonal coenoses are resistant for the penetration of alien species. The meadow component brings the most number of species into the plant diversity of the pine forests (23.3-25.2%). The pine forests, located in forest-steppe zone (Usmansky and Khrenovsky), are characterized by high species diversity of the forest and pine-forest component (20.4% and 20.2%), while in Buzuluksky and Krasnosamarsky pine forests, located in the steppe zone, it is significantly lower (19.6% and 15.7%, respectively). Meantime, the steppe component is more pronounced in the pine forests located in the steppe zone of the Trans-Volga Region (Buzuluksky, 21.9%, and Krasnosamarsky, 24.8%), while in forest-steppe pine forests Khrenovsky and Usmansky, it is quite lower, 16.4% and 15.5%, respectively. In the Usmansky pine forest, every third alien species of vascular plants is of cultural origin (escapee), in Khrenovsky and Buzuluksky, every fourth, and in Krasnosamarsky, every fifth species.
Changes in species richness of vascular plants under climate and solar radiation in the Middle Volga River region (Russia)
Authors: Sharaya L S , Shary P A , Ivanova A V , Kostina N V , Rozenberg G S 
Published: December 2020

Abstract
Specially protected natural conservation areas in the Middle Volga River region serve to preserve both rare and endangered species and the entire biotic complex, including typical floristic communities of vascular plants. We have identified 25 sites, 100 km2 each, where the flora is represented in full the most. We studied the relationships between the general species richness (SR) and the richness of particular life forms (LF) of vascular plants with climate and relief using multiple regression methods. Our study shows that the special function of March precipitation is the factor that influences the most the spatial change of the SR and LF. When increasing the precipitation in the model by only 1 mm, this leads to a decrease in the number of species by 7.1%. Winter precipitation and temperature are important factors as well; together they are responsible for 70-82% of the SR variation. These close links made it possible to develop the maps of the species richness of the study area. The SR model did not include solar radiation, one of the most important environmental factors, as a significant predictor. This factor was omitted due to the analysis of the number of species of particular LF, which showed the maximum illumination of the slopes as a highly significant factor for number of them. The two dominant LFs (hemicryptophytes and therophytes), which account for 73% of the total number of species, depend oppositely on the illumination. This fact indicates a decrease in competition between LFs due to their separation in space, since hemicryptophytes, in contrast to therophytes, predominate on well-illuminated slopes. In addition, opposite LF responses lead to omitting of illumination factor from the SR model for all species in the region.
Monetary valuation of rare plant species in the specially protected natural areas by example of the Samara Region (Russia)
Authors: Rozenberg A G , Kudinova G E , Kostina N V , Kuznetsova R S , Aristova M A , Ivanova A V 
Published: December 2020

Abstract
The approaches of assessing the ecosystem services are little implemented in Russia and are being developed recently at the regional level. Earlier, particular components of ecosystem services in the Samara Region have been evaluated. Here, an algorithm for monetary valuation of particular ecosystem services of specially protected natural areas is presented based on the data on rare and endangered plant species using the example of the Red List of the Samara Region. In total, 281 species of vascular plants have been analyzed, taking into account their spatial distribution in 27 municipal districts of the Samara Region. The ecosystem services were evaluated according to the formulas that took into account several parameters: (1) share of the area of specially protected natural areas; (2) number of tree and shrub species; (3) number of herbaceous plant species; (4) cost estimates; (4) expert assessments in the form of correction factors taking into account special value of relict and endemic species. The lower limit of the monetary value of ecosystem services, estimated by the only specially protected plant species, exceeds 50 million rubles. We suggest using this methodology for evaluating the ecosystem services in other territories, which will probably help to ensure the conservation and sustainable use of natural capital and natural ecosystems.
Environmental impact assessment of electromagnetic fields near to the specially protected natural areas on the example of Samara region of Russia
Authors: Vasilyev A V 
Published: December 2020

Abstract
Impact of physical pollutions (electromagnetic fields, noise, vibration, ionization etc.) is increasing every year and may cause significant discomfort and health damage of inhabitants of urban territories and of specially protected natural areas. Peculiarities of negative influence of electromagnetic fields to the man’s health and to environment are considered. Russian approaches to environmental impact assessment of electromagnetic fields of urban territories are discussed. It is pointed out that during environmental impact assessment it is necessary to undertake a complex of steps: identification of the most intensive sources of physical pollutions, calculations and measurements of physical pollutions propagation to the nearest living territories and of it impact to the workers of industrial enterprises, estimation of results of calculations and measurements, mapping of physical pollutions, development and implementation of measures to reduce negative impact of physical pollutions. Experience of realization of suggested approaches to environmental impact assessment of electromagnetic fields of territories are discussed on the example of Samara Region of Russia.
Influence of the water discharge of the Kuibyshev reservoir on the dynamics of the ecosystem of the Seredysh and Bakhilovsky islands, the Volga River, Russia
Authors: Bespalova K V , Selezneva A V , Seleznev V A 
Published: December 2020

Abstract
The state of the ecosystem of the protected islands Seredysh and Bakhilovsky (former Shalyga) is significantly affected by the water consumption in the power site of the Zhigulevskaya Dam. The 62-year dataset was analyzed to study the patterns of temporal variability of water discharge from the filling of the Kuibyshev Reservoir to the present. Long-term variability of the water discharge is due to climatic conditions in the Volga River basin, it follows to some extent the 22-year cycle of solar activity. Natural seasonal variability of the water discharge is altered by regulation at the Zhigulevskaya Dam, especially under unfavorable conditions for the formation of the water flow. The periods of low-water, high-water and medium water content were defined in regard to the annual water consumption. The low-water period lasted 19 years from 1958 to 1976, the high water period, 20 years from 1977 to 1998, and the period of medium water availability, 23 years from 1999 through 2019. Extreme high-water and low-water years, which had an adverse effect on the functioning of the islands’ ecosystem, were calculated using the empirical data on the water flow rate. During the spring flood of extremely high-water years, the water level in the reservoir increased sharply, so a part of the island was flooded. In the summer dry season of extremely dry years, the water level decreased, so the island area increased due to the shore retreat and appearing of sandbanks around the island. The negative impact of the water discharge on the ecological state of the islands may increase if the rules for regulating the water flow at the Zhigulevskaya Dam are violated.
Computer modeling of a non-stationary regime of distribution of the wastewater of Togliatti city in the coastal zone of the Bakhilovsky Island of the Middle Volga Integrated Biosphere Reserve (Saratov Reservoir, the Volga River, Russia)
Authors: Rakhuba A V 
Published: December 2020

Abstract
The formation of the pollution zones in the coastal water area of the Bakhilovsky Island belonging to the Middle Volga Integrated Biosphere Reserve was examined under the influence of a large source of wastewater discharge from the Togliatti city taking into account different phases of the daily flow regime of the Saratov Reservoir (the Volga River, Russia). Numerical simulation methods were used to calculate the flow fields and the transfer of the wastewater lenses at various water flow rates at the Zhigulevsk hydroelectric complex. Three typical scenarios for regulating water discharge were calculated: at night, during the day, and during the regulating releases. According to model calculations, the maximum pollution zone is formed in the area of wastewater discharge and in the vicinity of the Bakhilovsky Island during long-lasting regulating releases in the summer-autumn low-water period. The maps of the sewage plume distribution were developed, and vulnerable zones were defined for subsequent environmental monitoring of the water quality in the water area surrounding the protected island.
Current Carrying Characteristics of Energy-Saving and Loss-Reducing Conductor Joint
Authors: Lin Haofan , Ma YiLi , Jin YongTao , Yang Liming , Li Te , Yang Yong 
Published: December 2020

Abstract
The loss of submarine cable is an important problem in the process of design and manufacture. In this paper, the technology of the energy-saving and loss reducing conductor joint was introduced. The current carrying capacity test of energy-saving and loss-reducing conductor was carried out. At the same time, the same current was applied to the common stranded conductor and the energy-saving loss-reducing conductor, and the heat loss of the conductor under the same test environment was compared. The experimental results showed that at the connection of outgoing terminal and connecting pipe, the contact resistance of the layer insulated conductor was greatly reduced after depainting treatment. Meanwhile, the temperature of thermocouple after paint removal was obviously reduced in the current carrying capacity test. Compared with bare copper single wire stranded conductor, laminated enamelled insulated stranded conductor could reduce the power loss.
Generalized Prediction of Commercial Buildings Cooling and Heating Load Based on Machine Learning Technology
Authors: Liu Jianing , Zeng Kaiweng , Wang Haizhu , Du Bin , Tang Yufeng 
Published: December 2020

Abstract
Factors such as building area, materials, light transmittance, and housing orientation have significant effects on cold and heat loads of commercial buildings. Accurate prediction of cold and heat loads based on the characteristics of the building can provide a reliable data basis for power grid dispatch. In order to quantitatively study the influence of the commercial building factors on the cooling and heating load, this paper collected the load of 768 buildings in a certain area on a typical day in spring and the relative density, surface area, room orientation, and light transmission area of the building group. This paper uses typical machine learning methods such as random forest, extra random tree, bagging, and deep neural network to perform regression modeling on the data. Finally, three models with the best effects are selected for blending to obtain the final building cooling and heating load prediction model. In preset 156 test cases, the mean square error of the model for heat load prediction is 0.201 and the mean square error of cooling load forecast is 2.56. The blending model reduces the error to a smaller range and reduces the phenomenon of data overfitting.
Analysis of Affirming the Height of Weir Based on Fish Swimming Performance in Mountain River
Authors: Lei Hua , Aiju You , Kaiping Xu 
Published: December 2020

Abstract
The weir group has been great negative impact on fish migration, and there is no corresponding construction standard for the height of weir which may destroy fish migration. In this study, the discharge in extreme velocity of the local fish and submerged conditions of the weir was taken as a limitation of the height of the weir group in mountain area. Taking Majin River as an example, the height of weir was analyzed aiming for the local fish to get over the weir in migration period with one-dimensional hydrodynamics model. The results showed that the fish cannot pass through all weirs at a specific discharge with current weir height, by reducing the height of the weir, the discharge met to fish migration can be reduced, and different weirs required different heights to be reduced. The fish can pass through all weirs at a limited discharge with the weir heights reduced. This method provides a calculation method for determining the height of weir in mountain river.
A Study on the Path of Building Hefei as a Green Development City
Authors: Fang Tao , Sun Qian-qian 
Published: December 2020

Abstract
With “improving quality, reducing total amounts and preventing risks” as the mainline, Hefei adheres to ecological priority and the concept of symbiosis between cities and lakes, accelerates the transition towards green production methods, lifestyles and consumption patterns, and strides into a beautiful Hefei where “all lands are green, all waters are lucid, all seasons are scented with flowers and all places are resonant with singing birds”. This paper analyses the unique measures taken by Hefei for green development. On the basis of reviewing the main achievements and problems of Hefei’s green development, it proposes suggestions for reducing the excessive consumption of resources, comprehensively promoting industrial upgrading, disseminating ecological culture, strengthening the rule of law, environmental protection and eco-governance, and pushing forward the continuous improvement of ecological and environmental quality, so as to provide the decision-making basis for building Hefei as a green development demonstration city which realizes comprehensive, coordinated and sustainable development on economic, social and ecological aspects.
Research of Ti-6Al-4V titanium alloy welded joints made by electron beam welding, designed for operation in cryogenic conditions
Authors: Kovalev S V , Portnykh A I , Aslamova V Y 
Published: December 2020

Abstract
The article is based on realization of metallographic research in order to prove quality and following application of welded joint with the changed construction of coupling edges for details made of titanium alloy Ti-6Al-4V. The welded joint has been gained by electron beam welding. The expertise of macro- and microstructures has been realized, the hardness has been changed and testing of mechanical qualities under room and reduced temperature has been realized. The conclusion of possibility of application electron beam welding for welded joints of titanium spherical tanks is based on the research.
Production technology for polymeric composite materials by additive manufacturing methods
Authors: Egorov S A , Tarasova T V , Terekhina S M 
Published: December 2020

Abstract
Additive manufacturing methods make it possible to create complex geometry parts, that cannot be produced by conventional methods. For manufacture of the products, composite polymeric materials can be used, both disperse-filled and filled with short or continuous fibers. Recently, more and more attention has been paid to reinforcing plastics with natural fibers. The study of the manufacturing process of a polymeric composite material filled with continuous natural fibers by the fused filament fabrication is presented
Extruder for the production of metal-polymer filament for additive technologies
Authors: Roshchupkin S I , Golovin V I , Kolesov A G , Tarakhovskiy A Yu 
Published: December 2020

Abstract
In the process of performing the work, an extruder was designed for the manufacture of metal-polymer filament for additive technologies, of sufficient power, characterized in that it has a cooled screw, which allows to reduce the forces for mixing the mass, as well as a tungsten carbide coating, which has high wear resistance. The extruder will be loaded with a pre-prepared mixture consisting of polymer and metal powder.
The parameters values choice for the preliminary thermo mechanical effects on polymeric materials before machining
Authors: Erenkov O Yu , Lopushanskii I Ya , Yavorskii D O 
Published: December 2020

Abstract
In this paper the commonality of the destruction and materials cutting processes is substantiated. The use of preliminary mechanical and thermal effects on polymer composite materials is justified on the base on the provisions of the materials fracture kinetic concept. The ranges of the parameters values for thermal and mechanical effects on polymer composite materials are scientifically sound. Experimental studies of the polymeric materials deformation and fracture processes under uniaxial tension were carried out in order to select rational values of the preliminary mechanical stresses. It has been experimentally proved that the most weakened structure of the material is retained for 5-20 minutes for fluoroplastic and caprolon after preliminary loading. And the rest time between the deformation steps for thermosets such as getinaks and textolite does not affect the formation and change in the material strength.
Improving the accuracy of axisymmetric parts by applying controlled heat treatment
Authors: Drachev O I , Bobrowskii A V , Tisenko V N 
Published: December 2020

Abstract
The article discusses the technology of thermal power treatment of long, non-rigid parts of the “shaft” type. The design of the device for thermal-power deformation of the shaft and the principle of its operation are given. The device is equipped with a three-circuit automatic control system. The control system allows you to control the forces for axial deformation and the temperature of heating and cooling. The developed technology allows us to solve the problem of maintaining the straightness of the shaft during operation.
The wheels for final processing of parts
Authors: Dimov Yu , Podashev D 
Published: December 2020

Abstract
Microrelief characteristics of elastic abrasive wheel and parameters of its interaction with processed surface are studied (depth of penetration and quantity of penetrated grains). The received equitations of mathematical expectation of average depth of penetration of cutting logs and number of grains of elastic wheel being in contact allow to generate mathematical models of material removal and formation of parameters of roughness of the processed surface.
Rolling of a cylinder on the deformable surface with account of viscous lubricant
Authors: Zavyalov Oleg 
Published: December 2020

Abstract
A friction unit describing in this article consists of an absolute solid cylinder and a deformable surface. The cylinder rolls on the surface. The viscous liquid is applied to the surface as a lubricant. The surface is getting deformed if the cylinder is rolling under the load. This article demonstrates that if the cylinder is rolling without load, a locally thin layer of lubricant is formed between the surface and the cylinder. When the cylinder is rolling on the surface, the surface is deforming by the load. A thin layer of lubricant between the cylinder and the surface also exists. Moreover, the presence of a layer of the lubricant leads to an increase of an impact area and to a decrease in the load per surface unit. The distribution of pressure in the thin layer of liquid is calculated. The presence of the layer of viscous incompressible liquid in a cylinder-surface pair leads to an increase of a contact area and more even pressure distribution over the surface. As a result, the measures of pressure on the surface is significantly reduced. The rolling cylinder makes less pressure than it is calculated in statics.
The Investigation of lengthwise rolling on a stub mandrel by the use of a computer simulation
Authors: Pavlov D A , Erpalov M V 
Published: December 2020

Abstract
Lengthwise rolling of pipes on a stub mandrel is one of the most common pipe rolling methods. An urgent problem of the process of lengthwise rolling of pipes on a stub mandrel is the increased wall thickness variation in rough pipes caused by the flow of metal into the groove tapers and the formation of stripes during the rolling process. Therefore, an important direction is the study of the inhomogeneity of the metal flow in the deformation zone during the rolling process. To evaluate the wall thickness variation during the rolling process, a dimensionless parameter was introduced, which is the ratio of the average wall thickness variation in the groove tapers to the average wall thickness at the groove tops. The article presents the results of a study of the influence of mandrel calibration on the wall thickness variation and the tendency to form defects on the inner surface. With the use of computer simulation made for structural alloyed steel AISI-4140, the shape change of the pipe is investigated. Based on the studies, practical recommendations are formulated when choosing the calibration of the mandrel during lengthwise rolling on a stub mandrel, providing increased accuracy of pipes and reducing the level of defects.
Development of a sophisticated tool for processing parts with an involute profile
Authors: Ryazantsev Alexander , Shirokozhuhova Anna , Evchenko Irina 
Published: December 2020

Abstract
The article presents main parts of a modern propulsion system with liquid rocket engines. The critical parameters that affect the turbo-pump unit performance, as well as main methods of manufacturing gears in mechanical engineering, are shown. Standard and complex-profile tools used for machining parts with an involute profile are considered. Features of designing and manufacturing of complex cutting tools are revealed. Problems in the design of gear cutter used for gear machining are shown. The dependence of the gear cutter external diameter on the profile of the manufactured part is revealed. The mechanism and mathematical calculation of the tool profile adjustment are presented, taking into account the actual geometric dimensions of the manufactured part. The tool parameters that provide the specified critical parameters of parts with an involute profile are indicated. The proposed method of adjusting the geometric dimensions of a complex-shaped tool allows you to adjust and modify the final made gear cutters, which eliminates material and labor resources for the new expensive tool production.