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U-Pb dating of bastnäsite from the Vuoriyarvi massif:An example application for assessing the REE potential of carbonatite-related deposits

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Geoscience Frontiers 2024年第5期15卷 444-453页

作者： evgeniy n.kozlov Ekaterina n.Fomina Qiuli Li Jiao Li Geological Institute Kola Science Centre of the Russian Academy of SciencesApatity 184209Russia Institute of Geology and Geophysics Chinese Academy of SciencesBeijing 100029China

The Vuoriyarvi massif is a Devonian multistage alkaline-ultrabasic carbonatite complex within the Kola alkaline *** carbonatites of the Vuoriyarvi massif contain abundant rare-earth mineralization mainly represented by ancylite-(Ce)and bastnäsite-(Ce).Ancylite was previously shown to have probably formed in the Devonian(ca.365 Ma)during an early postmagmatic *** geological observations have revealed a much later crystallization of bastnäsite but have not been able to specify the exact age of the *** in situ U-Pb dating of bastnäsite allowed us to constrain its ***äsite for this study was extracted from two varieties of dolomite carbonatite breccias cemented by(1)quartz-bastnäsite and(2)strontianite aggregates(hereafter bastnäsite-rich and strontianite-rich carbonatites–BRC and SRC,respectively).The obtained age estimations(237.7±9.8 Ma and 239.9±4.1 Ma,respectively)indicate that both studied rocks were formed during a single *** revealed age difference(~125 Ma)excludes the genetic link between the bastnäsite origin and regional alkaline magmatism,pointing out an additional source for the Vuoriyarvi bastnäsite-bearing ***,the obtained U-Pb ages provide strong evidence that a Triassic event is responsible for the occurrence of bastnäsite mineralization due to hydrothermal REE redistribution from the Devonian ancylite-rich *** of the REEs released during this process via dissolution of ancylite were precipitated in situ as bastnäsite,while strontium was transported and incorporated into *** Pb isotopic characteristics of bastnäsite(^(206)Pb/^(204)Pb=18.1±0.1,^(207)Pb/^(204)Pb=15.3±0.1,and^(207)Pb/^(206)Pb=0.84±0.01)are most probably inherited from the Devonian host rocks of the Vuoriyarvi massif involved in the Triassic *** signatures of Pb,Sr,and nd show that the depleted mantle and lower crust played the leading role in formation of the Vuoriyarvi alkaline

关键词： Bastnäsite REE Carbonatites U-Pb dating Vuoriyarvi Kola alkaline province

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Morphology of crater and caldera lakes in the Far Eastern region of Russia and the features of their development

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Journal of Mountain Science 2024年第4期21卷 1246-1258页

作者： Dmitrii n.kozlov Ekaterina V.LEBEDEVA Institute of Marine Geology and Geophysics Far Eastern Branch of the Russian Academy of SciencesYuzhno-Sakhalinsk 693022Russia Institute of Geography Russian Academy of SciencesMoscow 119017Russia

Volcanic lakes in the Kuril-Kamchatka region are difficult to access,and for this reason,they remain poorly studied,with only scattered and brief data *** authors have conducted a study of 10 lake basins using modern digital echolocation survey techniques and have also compiled and summarized published data for 15 lakes in the region,calculating their main morphometric *** has been established that many caldera lake basins are modified by young explosive funnels,extrusive or effusive domes,and exhibit traces of hydrothermal *** lakes of the same genetic type in the Kuril-Kamchatka region are similar in depth and depression forms,the group of caldera lakes shows less homogeneity across all morphometric *** was found that the absolute heights of the reservoirs on Kamchatka Peninsula are generally greater than those on the Kuril Islands,as is often the case with the size of their *** volcanic lakes under study can rapidly change their volume and shape under the influence of endogenous *** the first time for this region,on the base of repeated observations,underwater extrusive dome rate growth and the approximate rates of 2 lake level changes were *** observations of lakes in the Ksudach calderas(Kamchatka)and on Simushir Island indicate approximate rates of level changes:a decrease ranging within 0.5-0.6 m per year(over a 27-year observation interval)and an increase reaching up to 0.26 m per year(over a 48-year interval).The growth rate of the underwater extrusive dome in Lake Shtyubel has averaged 1-1.6 m per year over the past 25 *** analysis has facilitated the first generalization regarding the morphology and developmental features of crater and caldera lakes in the Kuril-Kamchatka region of Russia,representing an important step in their *** results obtained will provide a solid foundation for subsequent research in this region and may be of interest to researchers studying

关键词： Volcanic lakes Echolocation survey Volcanism Gashydrotherms Kamchatka Kuril Islands

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Agglomeration of coal and polyethylene mixtures during fixed‑bed co‑gasification

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International Journal of Coal Science & Technology 2024年第2期11卷 91-100页

作者： Igor G.Donskoy Aleksandr n.kozlov Maksim V.Penzik Denis A.Svishchev Lu Ding Melentiev Energy Systems Institute Russian Federation130 Lermontova StreetIrkutskRussia 664033 East China University of Science and Technology 130 Meilong RoadShanghai 200237China

The article presents the results of experimental studies on the gasification of mixtures of brown coal and polyethylene(up to 20 wt%fraction)in a laboratory *** work aims to study the agglomeration process during the heating and oxidation of the *** measurement results(gas composition,pressure drop)provide indirect information on the dynamics of thermal decomposition and structural changes in the fuel *** have shown that the interaction between polyethylene and a coal surface leads to the formation of dense agglomerates,in which the molten polymer acts as a *** form as a result of interfacial interactions between components and filtration flow *** hydrogen/carbon ratio in the solid residue of coal-polyethylene co-gasification increases from 0.07–0.2 to 1.11,indicating the formation of stable hydrocarbon compounds on the carbon *** conducted research makes it possible to identify possible interactions between chemical reactions and transfer processes that lead to agglomeration in mixtures of coal with polyethylene.

关键词： Coal Polyethylene Gasification Combustion Agglomeration

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Environmental performance assessments of different methods of coal preparation for use in small-capacity boilers: experiment and theory

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International Journal of Coal Science & Technology 2023年第5期10卷 57-71页

作者： A.n.kozlov E.P.Maysyuk I.Yu.Ivanova Melentiev Energy Systems Institute of Siberian Branch of the Russian Academy of Sciences Irkutsk130Lermontov664033Russia

The purpose of this article is to receive environmental assessments of combustion of different types of coal fuel depending on the preparation(unscreened,size-graded,briquetted and heat-treated)in automated boilers and boilers with manual *** assessments were made on the basis of data obtained from experimental methods of coal preparation and calculated methods of determining the amount of pollutant and greenhouse gas emissions,as well as the mass of ash and slag *** main pollutants from coal combustion are calculated:particulate matter,benz(a)pyrene,nitrogen oxides,sulfur dioxide,carbon *** the greenhouse gases carbon dioxide is *** a result of conducted research it is shown that the simplest preliminary preparation(size-graded)of coal significantly improves combustion efficiency and environmental performance:emissions are reduced by 13%for hard coal and up to 20%for brown *** introduction of automated boil-ers with heat-treated coal in small boiler facilities allows to reduce emissions and ash and slag waste by 2-3 *** best environmental indicators correspond to heat-treated lignite,which is characterized by the absence of sulfur dioxide emissions.

关键词： Coal preparation Automated and hand-fed coal boilers Environmental performance metrics

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Energy of Grain Boundaries of Different Type in fcc Solid Solutions,Ordered Alloys and Intermetallics with L1_2 Superstructure

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Journal of Materials Science & Technology 2003年第6期19卷 593-596页

作者： O.B.Perevalova E.V.Konovalova n.A.Koneva E.V.kozlov Institute of Strength Physics and Materials Science Russian Academy of Science Siberian Branch Russia TomskState University of Architecture and Building Russia TomskState University of Architecture and Building Russia TomskState University of Architecture and Building Russia Tomsk

The study of the triple junctions of the grain boundaries in some fee solid solutions, ordered alloys and intermetallics with L12 has been carried out using the optical metallography and TEM methods. Two-types of the triple junctions were found in the alloys investigated (1), consisting of the boundaries of the random (RT), and (2), consisting of the RT boundary and the special boundaries (ST). The relative values of the RT and ST boundary energy were determined on the basis of the measurements of the angles between the grain boundary planes. It has been shown that the energy of ST boundaries increases with the increase of the stacking fault (SF) energy. The energy of the RT boundaries does not depend on the SF energy.

关键词： Alloys Grain boundary energy Stacking fault Anti-phase-boundary

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The Study of the Secrets of the Genetic Code

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Journal of Computer and Communications 2018年第7期6卷 64-83页

作者： n. n.kozlov Keldysh Institute of Applied Mathematics of Russian Academy of Sciences Moscow Russia

The disclosure of many secrets of the genetic code was facilitated by the fact that it was carried out on the basis of mathematical analysis of experimental data: the diversity of genes, their structures and genetic codes. new properties of the genetic code are presented and its most important integral characteristics are established. Two groups of such characteristics were distinguished. The first group refers to the integral characteristics for the areas of DnA, where genes are broken down in pairs and all 5 cases of overlap, allowed by the structure of DnA, were investigated. The second group of characteristics refers to the most extended areas of DnA in which there is no genetic overlap. The interrelation of the established integral characteristics in these groups is shown. As a result, a number of previously unknown effects were discovered. It was possible to establish two functions in which all the over-understood codons in mitochondrial genetic codes (human and other organizations) participate, as well as a significant difference in the integral characteristics of such codes compared to the standard code. Other properties of the structure of the genetic code following from the obtained results are also established. The obtained results allowed us to set and solve one of the new breakthrough problems—the calculation of the genetic code. The full version of the solution to this problem was published in this journal in August 2017.

关键词： Genetic Code Overlapping Genes Degeneracy Code Code Irregularities Potential Code for Overlaps Common Property Codes Integral Characteristics Code Deviation Code Elementary Overlaps Role-Reinterpreted Codons Code Is not Arbitrary

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Computation of the Genetic Code: Full Version

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Journal of Computer and Communications 2017年第10期5卷 78-94页

作者： n. n. kozlov Keldysh Institute of Applied Mathematics of Russian Academy of Sciences Moscow Russia

One of the problems in the development of mathematical theory of the genetic code (summary is presented in [1], the detailed—to [2]) is the problem of the calculation of the genetic code. Similar problem in the world is unknown and could be delivered only in the 21st century. One approach to solving this problem is devoted to this work. For the first time a detailed description of the method of calculation of the genetic code was provided, the idea of which was first published earlier [3]), and the choice of one of the most important sets for the calculation was based on an article [4]. Such a set of amino acid corresponds to a complete set of representation of the plurality of overlapping triple gene belonging to the same DnA strand. A separate issue was the initial point, triggering an iterative search process all codes submitted by the initial data. Mathematical analysis has shown that the said set contains some ambiguities, which have been founded because of our proposed compressed representation of the set. As a result, the developed method of calculation was reduced to two main stages of research, where at the first stage only single-valued domains were used in the calculations. The proposed approach made it possible to significantly reduce the amount of computation at each step in this complex discrete structure.

关键词： Genetic Code Overlapping Genes Uniform Overlap Computation Code

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Cumulation of a spherically converging shock wave in metals and its dependence on elastic-plastic properties, phase transitions, spall and shear fractures

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International Journal of Modeling, Simulation, and Scientific Computing 2015年第1期6卷 26-38页

作者： Evgeny A.kozlov Alexsander V.Petrovtsev Russian Federal nuclear Center-Zababakhin Research Institute of Technical Physics Snezhinsk Chelyabinsk RegionRussia

Consideration is given to results of experimental and theoretical investigations how alpha-epsilon phase transition in the unalloyed iron and the 30 KhGSA steel and its absence in the austenitic 12Kh18n10T stainless steel influence processes under explosive deformation of spheres made of these *** transition is shown to significantly effect on:amount of explosion-products energy transferred to a sphere,evolution of the converging-wave structure and its parameters,profiles of stress wave and temperature T(R,t)for some Lagrangian particles along the sphere radius,character of energy cumulation under spherical convergence of waves.

关键词： Cumulation spherically converging shock wave elastic-plastic properties phase transitions spall and shear fractures

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numerical 3D-modeling of spall and shear fractures in shells of austenitic 12Kh18n10T steel and 30KhGSA steel under their spherical and quasi-spherical explosive loading

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International Journal of Modeling, Simulation, and Scientific Computing 2015年第1期6卷 173-211页

作者： Evgeny A.kozlov Oleg V.Ol’khov Ekaterina V.Shuvalova Russian Federal nuclear Center–Zababakhin Research Institute of Technical Physics Snezhinsk Russia Russian Federal nuclear Center–Research Institute of Experimental Physics Sarov Russia

To pursue VnIIEF–VnIITF joint investigations,this paper briefly describes the experimental setup and provides numerical 3D-computation results(LEGAK-3D technique)on special features in the convergence dynamics of steel shells under their quasi-spherical explosive loading in the system with the 40-mm outer radius of the explosive *** computation results were compared with the data experimentally registered for shells of the 30KhGSA steel,both as-received and quenched to HRC 35...40,and the austenitic 12Kh18n10T stainless *** comparison was also made with laserinterferometry results obtained directly under explosive loading,as well as with gammatomography and scanning electron microscopy investigations of the recovered shells.

关键词： Convergence dynamics of shell spall and shear damages explosive loading

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Poleward increase in feeding efficiency of leafminer Stigmella lapponica(Lepidoptera:nepticulidae)in a latitudinal gradient crossing a boreal forest zone

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Insect Science 2023年第3期30卷 857-866页

作者： Mikhail V.kozlov Vitali Zverev Tobias M.Sandner Erik J.van nieukerken Elena L.Zvereva Department of Biology University of TurkuTurkuFinland Department of Biology Philipps-Universitat MarburgMarburgGermany naturalis Biodiversity Center Leidenthe Netherlands

Damage to plant communities imposed by insect herbivores generally decreases from low to high *** decrease is routinely attributed to declines in herbivore abundance and/or diversity,whereas latitudinal changes in per capita food consumption remain virtually ***,we tested the hypothesis that the lifetime food consumption by a herbivore individual decreases from low to high latitudes due to a temperature-driven decrease in metabolic *** 2016 to 2019,we explored latitudinal changes in multiple characteristics of linear(gallery)mines made by larvae of the pygmy moth,Stigmella lapponica,in leaves of downy birch,Betula *** mined leaves were larger than intact leaves at the southern end of our latitudinal gradient(at 60°n)but smaller than intact leaves at its northern end(at 69°n),suggesting that female oviposition preference changes with *** latitudinal changes were observed in larval size,mine length or area,and in per capita food consumption,but the larval feeding efficiency(quantified as the ratio between larval size and mine size)increased with ***,*** larvae consumed less foliar biomass at higher latitudes than at lower latitudes to reach the same *** on space-for-time substitution,we suggest that climate warming will increase metabolic expenses of insect herbivores with uncertain consequences for plant-herbivore interactions.

关键词： Betula pubescens climate change food quality insect herbivory metabolic expenses oviposition preference

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