bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distinctive features of heavy metals’ accumulation in coniferous trees in Buryatia, Russia
Authors: Erdyneeva S A , Shiretorova V G , Radnaeva L D 
Published: August 2019

Abstract
Coniferous plants are very sensitive to atmospheric pollutants and frequently are used as environment pollution bioindicators. The purpose of this study was to define features of heavy metals (HM) accumulation by conifer needles from forest-forming tree species growing in Buryatia: Pinus sylvestris, Pinus pumila, Pinus sibirica, Picea obovata, Abies sibirica. The samples elements content was determined by ICP AES method after acid decomposition in microwave system MARS 6. HM accumulation rows showed similar trends for different tree species. The maximum content was determined for manganese in all needles samples, except Pinus sylvestris, growing around Ulan-Ude. It is shown that there is a difference in HM accumulation between conifer species due to their biological features. The variation coefficient of heavy metals in conifer needles were calculated, Zn, Ni, Hg exposed highest level of variation. Industrial pollution caused the significant changes in the needles elemental composition – it is observed the growth of Fe, Zn and lowering of Mn content in Pinus sylvestris needles growing around Ulan-Ude. The accumulation of HM by conifer needles growing in Buryatia was higher than the average terrestrial vegetation element contents that might be related with the forest fires.
Ecological and geomorphological assessment in the structure of natural potential for the Russian coast of the Azov Sea
Authors: Ivliyeva O V , Kushnir K V 
Published: August 2019

Abstract
Morphological attractiveness of the Azov Sea beaches is determined, analysis of the beach area pollution is carried out, the most favorable territories for the recreational development are marked out. They include the northern coast of the Kerch peninsula, eastern coast of the Sea from Taman to Temernyuk, Dolzhansk and Eask spits and Taganrog gulf spits.
Prospects for the use of non-metallic construction materials in the Republic of Buryatia
Authors: Dmitrieva N G 
Published: August 2019

Abstract
This article gives a brief description of the deposits and occurrences of various types of mineral building raw materials in the area of the formation of the Eravninsky ore district. The prospects for the use of non - metallic construction materials for the implementation of large investment projects based on the use of a rich raw material base of the region are considered.
Geoecological assessment of the Vilyuy river state under technogenic impact conditions of the diamond mining industry
Authors: Ksenofontova M I , Danilov P P , Popova A G , Gabysheva A A , Kanaeva A N 
Published: August 2019

Abstract
The article presents the preliminary results of the study of surface waters and bottom sediments of the rivers Irelyakh, Malaya Botuobiya and Vilyuy after the technological accident in August 2018. In general, after the accident burst of the dredging site on the Irelyakh deterioration of water quality in the Vilyuy by organoleptic characteristics (chromaticity up to 20 MPC, turbidity up to 61 MPC), as well as the most important indicators such as BOD5 (up to 3.9 MPC) and COD (4.5 MPCvr, 2.2 MPC) is detected. High concentrations of suspended solids, turbidity and chromaticity are observed in the channel of the Vilyuy below the mouth of the Markha in the period 02-03 September 2018, where the bulk of the polluted water passed. In the trace element composition of water, the main pollutants are total iron (up to 22 TLV f.w., 7.5 MACw), manganese (up to 12.6 TLV f.w.), aluminum (up to 32.3 TLV f.w., 6.5 MACw) and copper (up to 37 TLV f.w.)
The experience of developing large-scale geobotanical maps based on field and remote sensing data
Authors: Zharnikova M A , Alymbaeva Zh B , Sodnomov B V , Ayurzhanaev A A 
Published: August 2019

Abstract
The article discusses the experience of compiling large-scale vegetation maps, the advantages of using aerial photography data from a radio-controlled unmanned aerial vehicle (UAV) and the technology of geo-information systems in combination with ground-based traditional geobotanical mapping methods. The use of remote sensing data is one of the ways to quickly obtain data for vegetation mapping. Currently this method is actively used and developed. However, satellite data has several disadvantages. The use of UAV is a promising direction for timely and cost-effective environmental monitoring. Using the aerial photo obtained in this way, it is possible, on the one hand, to trace the dynamics of vegetation during one season, and on the other, to identify and map both different plant communities and populations of individual species that do not coincide in the phenological phase of development with each other. The aim of the study was to reflect the heterogeneity of vegetation cover on a detailed geobotanical map in a simple way, which will act as the basis for further research. The map constructed by the described method is the most objective reflection of the state of the vegetation cover.
Vegetation cover dynamics of Russia and Mongolia border territories
Authors: Sodnomov B V , Ayurzhanaev A A , Tsydypov B Z , Zharnikova M A , Batomunkuev V S , Zh Garmaev E 
Published: August 2019

Abstract
Desertification is one of the most complex environmental problems in the Central Asian region. In addition to climatic factors affecting land degradation, in the border territories of Russia and Mongolia the intensification of desertification processes is influenced by human activities. A cartographic analysis of meteorological parameters, as well as vegetation state and dynamics spatial distribution based on the NDVI, was carried out. Dry zones occupy 65% of the area of Russia-Mongolia border territories. The prevailing climate zone is a semi-arid. The features of the dynamics of vegetation in the wet (1982-1999) and drought (2000-2015) periods are revealed. In the period from 1982 to 2015 a positive trend of NDVI is observed for 78% of the border areas and negative is for 22%. During the wet period the area of negative trends for both Russia and Mongolia amount 1.5% of the territory, primarily due to deforestation. The drought period is characterized by a nearly twentyfold increase in the areas of negative NDVI trends for the whole border territory. The analysis of the correlation of meteorological parameters and vegetation revealed that in drylands with negative NDVI trend, climate-induced desertification covers 63%, and anthropogenic 37% of the total area affected by desertification.
Assessment of spatial and temporal dynamics of the Selenga River channel deformation
Authors: Tsydypov B Z , Ayurzhanaev A A , Chernykh V V , Gurzhapov B O , Zh Garmaev E 
Published: August 2019

Abstract
The identification of spatio-temporal patterns of transformation of the Selenga river channel is an important task, which has both theoretical and practical importance. Dynamic seasonal and long-term changes in the levels and flow rates of water in the Selenga river, as well as significant kinetic energy of the flow cause a high intensity of channel processes, which must be taken into account in the construction and operation of hydrotechnical and shore protection, as well as other protective structures. A retrospective comparative analysis of the dynamics of channel deformation based on the thematic automated interpretation of Landsat satellite multi-temporal data is carried out. This, together with engineering hydrological calculations, allowed us to perform a qualitative and quantitative assessment of the results of the long-term manifestation of natural processes in a vast area occupying part of the Selenga valley from the state border to its delta. In the course of work, for the first time a map of the Selenga river channel dynamics. Areas with different types of channel stability have been identified, the channel classification has been carried out into meandering, straight and braided sections.
Removal of anionic surfactants from aqueous solutions using Fe-aluminosilicate sorbents
Authors: Ts Khankhasaeva S 
Published: August 2019

Abstract
Fe-aluminosilicate sorbents were obtained by modifying bentonite clay with iron polyoxocations and heat treatment at 400°C and 500°C. The specific surface of the sorbents determined by the method of low-temperature nitrogen adsorption was 118-136 m2 · g–1. The iron content in sorbents was equal 7.8 %. The adsorption properties of the obtained sorbents were studied with respect to anionic surfactants (sodium dodecyl sulfate and sodium dodecylbenzenesulfonate) in aqueous solutions. It was shown that the modification of clay leads to a significant increase in anion-exchange capacity. The value of the adsorption capacity was in good agreement with the increase in the number of the basic groups of Fe – OH and the value of the specific surface of the sorbents. Adsorption isotherms of sodium dodecyl sulfate on bentonite clay and on Fe –aluminosilicate sorbents are described by the Langmuir adsorption isotherm equation which describes monolayer adsorption on a homogeneous surface with a correlation coefficient of 1.000 at initial surfactant concentrations of 10-1000 mg · l–1. The adsorption capacity of Fe-aluminosilicate sorbents was more than 3 times higher than the capacity of the original clay in the adsorption of sodium dodecyl sulfate and was about 5 times higher in the adsorption of sodium dodecylbenzenesulfonate. The results of the study suggest that the Fe-aluminosilicate sorbents can be effective for removing anionic surfactants from wastewater.
Extraction of heavy metals from multicomponent solutions
Authors: Budaeva A D , Antropova I G , Alekseeva E N 
Published: August 2019

Abstract
The paper presents the results of studying the absorption of heavy metal ions from a multicomponent solution by coal mining waste. Acidic drainage solution was obtained by water leaching of technogenic sand of tungsten-molybdenum factory. It was found that manganese, zinc, copper and iron have high concentrations in the solution. Copper, iron and lead have a high affinity for the surface of coal. The usage of oxidized brown coal as an adsorbent can significantly reduce the concentration of heavy metals in multicomponent solutions despite their complex composition.
Application of magnesium silicate rocks in the production of cements with mineral additives
Authors: Khudyakova L I , Paleev P L 
Published: August 2019

Abstract
Cement plants are among the main sources of environmental pollution. They emit a huge amount of carbon dioxide into the atmosphere, make a significant contribution to the greenhouse effect. To eliminate this drawback, the enterprises switch to the production of cements with mineral additives. Serpentinites can be used as innovative mineral supplements. These are the magnesium silicate rocks moved to dumps in the process of development of mineral deposits. Their introduction into the composition of cements allows to produce high quality materials. At the same time, their physical and mechanical properties depend on the amount of additives and on the time of grinding the raw mixture. It is shown that the optimal parameters for obtaining cements are: the addition of serpentinite (up to 30 %) with grinding time of 10 minutes. Under these conditions, composite binders have the best strength characteristics. The usage of serpentinites in Portland cement production process will not only expand the list of raw materials for the construction industry, but also solve environmental problems associated with the storage and disposal of mining waste.
The content and distribution of lead in the permafrost soils of the northern-taiga landscapes of Yakutia
Authors: Gololobova A G , Gabysheva A A 
Published: August 2019

Abstract
We studied the content and nature of the distribution of lead in permafrost soils of the “Burannyi” site of the Tomtor rare-earth deposit. We explored three types of permafrost soils with low power of the soil profile: permafrost fawn-brown podzolized, permafrost fawn-brown and homogeneous non-gleyed cryozem. An experiment on lead sorption by genetic horizons of permafrost soil was constructed in the laboratory. The contents of the mobile forms of Pb in the studied soils are arranged in the ascending order: homogeneous non-gleyed cryozem < permafrost fawn-brown < permafrost fawn-brown podzolized. The experiment identified high correlation dependence of the lead content on humus values, as well as the average negative dependence on pH. Based on the constructed sorption model, it claims that the mineral horizons have the highest sorption capacity.
Thermodynamic modeling effect of fullerenes C60 and C70 on phase composition and hydration of Portland cement
Authors: Smirnyagina N N , Tsyrenov B O , Dasheev D E , Urkhanova L A , Lkhasaranov S A 
Published: August 2019

Abstract
This paper presents thermodynamic calculations of the hydration of cement stone with carbon nanomodifier. Carbon nanomodifier was obtained at atmospheric pressure and elevated helium pressure in arc discharge. Cement stone with the use of carbon nano-modifier has improved physical and mechanical properties. Thermodynamic calculations showed that with the addition of carbon nanomodifiers, the phase composition and the kinetics of the hydration of cement stone change.
Purification of aqueous solutions of methylene blue by adsorption on montmorillonite
Authors: Badmaeva S V 
Published: August 2019

Abstract
The adsorption of cationic dye methylene blue on natural and Fe-modified materials obtaining two methods was investigated. It was established that adsorptive capacity of natural and Fe-modified materials depends on their cation-exchange capacity. It was determined that the adsorption capacity of Fe-modified materials with respect to the dye “methylene blue” in aqueous solution depends on the method of obtaining. The adsorption of methylene blue on sorbents describes by Langmuir model (the correlation coefficients are 0.9858-1.0000), which corresponds to monolayer adsorption on a homogeneous surface.
Assessment of acute and chronic toxicity of water-soluble polyguanidines towards hydrobionts
Authors: Stelmakh S A , Grigor’eva M N , Tikhonenkov D V , Ochirov O S , Mognonov D M 
Published: August 2019

AbstractThere were obtained water-soluble polyguanidines of various structures and molecular weights by polycondensation in the melt of aliphatic amines and guanidine hydrochloride in the presented report. There was assessed the toxicity of a number of polymeric compounds in the acute and chronic experiment on fish. In turn this allowed the visionof the link between the structure of the macromolecular chain and toxic action. There was established the average fatal concentration and the threshold level of the fatal effect, which does not exceed the range of 0.5-2.5 mg/l for different polymer structures. Taking into account the fact that such concentrations are destructive for many unicellular organisms, it is possible to predict their high efficiency in the fight against ectoparasites of fish.
Synthesis of Li3BaSrGd3(MoO4)8 doped with Ce3+ ions
Authors: Kozhevnikova N M , Yu Batueva S 
Published: August 2019

Abstract
The Li3BaSrGd3(MoO4)8:Ce3+ phosphor was synthesized by solid-state reaction and studied by X-ray diffraction analysis, differential-thermal analysis, and IR spectroscopy. The Li3BaSrGd3(MoO4)8:Ce3+ crystallizes in the monoclinic structure with space group C2/c, Z = 2. The luminescence properties of this resulting phosphor are characterized by photoluminescence (PL) emission spectra and excitation (PLE).
Perspective ion-conducting materials based on complex tungstates
Authors: Dorzhieva S G , Bazarov B G , Subanakov A K , Bazarova J G 
Published: August 2019

Abstract
Novel electrolytes based on complex tungstates with general formula CsRTi0.5(WO4)3 (R = Al, Cr) were investigated. X-ray diffraction results show that the single-phase samples can be formed by ceramic technology at 1023 K. Dielectric measurement results indicate that the conductivity of CsCrTi0.5(WO4)3 can reach 0.0011 S cm−1 at 1023 K. The activation energy of the compound calculated according to the Arrhenius plots are 0.4-0.6 eV for T > 873 K. Impedance spectra of the ceramic samples at different temperatures are characterized the high frequency semicircle and a straight line at low frequencies, which is typical for ion-conducting materials. CsRTi0.5(WO4)3 (R = Al, Cr) ceramic materials correspond to a new strategy to design novel electrolytes for various applications.
Development of assay method by HPLC-DAD for the quantitative determination of chromones in Saposhnikovia divaricata radices and its validation
Authors: Urbagarova B M , Taraskin V V , Shul’ts E E , Radnaeva L D 
Published: August 2019

Abstract
Assay method using high performance liquid chromatography with diode array detection was developed and validated for the determination of chromones: prim-Oglucosylcimifugin, cimifugin, 4’-O-β-D-glucosyl-5-O-methylisamminol. Chromatographic method for the determination of chromones was validated for specificity, linearity, accuracy, repeatability and intermediate precision. The optimal conditions for the extraction of chromones from the Saposhnikoviae divaricatae radices were selected. It was found that these substances are better extracted with 50% ethanol using ultrasonic extraction at room temperature. The quantity of chromones in Saposhnikoviae Radix of the flora of Buryatia was also determined.
Fatty acid composition of Artemisia santolinifolia Turcz. ex Bess. of flora of Buryatia
Authors: Tsybikova S Z , Randalova T E , Radnaeva L D 
Published: August 2019

Abstract
For the first time, the chromatographic mass spectrometry has been used to study the qualitative composition and quantitative content of the fatty acids of Artemisia santolinifolia Turch. Ex Bess. at different stages of plant development. The study revealed 25 fatty acids, including 18 saturated and 7 unsaturated. The dominant components are palmitic, linoleic, oleic and α-linolenic acids. Comparison of the composition of fatty acids obtained from samples isolated from plants at different phases of development showed that at the beginning of flowering the proportion of SFA (51.80%) is almost equal to the proportion of UFA, (48.20%), at the end of flowering and in the phase of fruiting in both samples the content of SFA (59.44-65.01%) is significantly greater than the UFA (34.98-40.59%).
Polymer composite materials based on ultra-high molecular weight polyethylene and modified montmorillonite
Authors: Danilova S N , Okhlopkova A A , Sleptsova S A , Ivanov A N , Grigoreva L A , Spiridonov A M 
Published: August 2019

AbstractThe research paper presents the results of studies of the influence of organically modified montmorillonite (OMMT), grade 101/102, on the mechanical and tribological characteristics of the ultra-high molecular weight polyethylene (UHMWPE). The filler was introduced into the polymer matrix in 0.5, 1 and 2 wt. % content. Samples for testing were obtained by hot pressing. It was found that adding 0.5 wt. % OMMT in ultra-high molecular weight polyethylene leads to improving the tensile strength by 23 % and elasticity modulus by 14 % relative to the unfilled polymer. It has been shown that the mass wear rate of the material under dry sliding friction was reduced by 1.5 times and linear wear by 2.8 times compared with initial ultra-high molecular weight polyethylene.
Mechanical properties and crack resistance of sustainable high strength engineered cementitious composites
Authors: Han Y D , Wang Q , Wang Z B , Yao B Y 
Published: August 2019

Abstract
Engineered cementitious composite (ECC) is a class of high performance fiber reinforced material designed to overcome the brittleness of concrete. The high content of cementitious material restricts the common application of ECC. To develop a new series of sustainable and durable composite, industrial wastes such as fly ash, silica fume and furnace slag were brought in as supplementary cementitious materials (SCMs) in present study. High strength cement matrixes with three types of SCMs were obtained. Tensile performance of PVA-steel fiber reinforced engineered cementitious composite based on above matrixes were evaluated via uniaxial tensile test. Crack resistance of high strength engineered cementitious composite (HSECC) with industrial wastes were experimentally estimated through steel ring test. Results show that suitable addition of industrial wastes somehow improved the mechanical performance and crack resistance of HSECC and further enhanced the durability and sustainability.
Research on rapid semi-quantitative determination of aluminum in pyrotechnics used for fireworks and firecrackers
Authors: Wu Junyi 
Published: August 2019

Abstract
This study discloses a method for rapid semi-quantitative determination of aluminum in pyrotechnic powder for fireworks and firecrackers based on energy dispersive X-ray fluorescence spectrometer (EDXRF), including the following steps: preparation of samples, establishment of testing methods, determination of the characteristic line fluorescence intensity values of Al element in samples, and according to the measured fluorescence intensity values, the aluminum content in the pyrotechnic powder samples can be semi-quantitatively determined. The method of the study has the advantages like that: (1) the method is simple to operate, and it can be repeatedly called for testing. Only one new test method needs to be built before the sample test. After the method is established, the test can be repeated at different times without re-establishing the test method for each test. After the first establishment of the new test method, the entire test process only includes three steps: sample preparation, sample loading into the sample cup and on-board testing. (2) The testing time is extremely short. After the sample is prepared, the entire measurement process takes only about 2 minutes. (3) Labor intensity is very low and the requirements for operators are not very strict. (4) The method has good stability, good repeatability and high credibility.
Towards a theory of multi-parameter geometrical variational problems: Fibre bundles, differential forms, and Riemannian quasiconvexity
Authors: Li Siran 
Published: August 2019

We are concerned with the existence and associated gauge problems of a general class of geometrical minimisation problems, with action integrals defined via differential forms over fibre bundles. We find natural algebraic and analytic conditions which give rise to an associated gauge theory. Moreover, we propose the notion of “Riemannian quasiconvexity” for cost functions whose variables are differential forms on Riemannian manifolds, which extends the classical quasiconvexity condition in the Euclidean settings. The existence of minimisers under the Riemannian quasiconvexity condition has been established. This work may serve as a tentative generalisation of the framework developed in the recent paper [Arch. Ration. Mech. Anal. 234 (2019), pp. 317–349] by Dacorogna–Gangbo.