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Journal of Forestry Research 2023年第5期34卷 1279-1287页

作者： aleksandr v.lebedev Department of Agricultural Meliorations Forestry and Land OrganizationRussian State Agrarian University-Moscow Timiryazev Agricultural AcademyTimiryazevskaya49MoscowRussia 127434

A century and a half ago,in the European part of Russia(Moscow),forest scientists established the first long-term observations of forests,many of which are under observation to the present *** the twentieth century,climate changes and,due to industrial development,forest areas were under air *** on observations from 157 sites,this study shows that the growth and density of Scots pine(Pinus sylvestris L.)have decreased by the end of the twentieth *** environment has changed,and the growth and development of plantations has *** yields(-34%stand volume)and their life expectancy(on average 50 years)have *** changes are critical for forestry and for the management of forests in urban *** to the decline in growth,ecosystem functions by urban forests has *** order to increase the sustainability of urban forests and the provision of ecosystem services,it is preferable to create multi-species stands with a complex structure.

关键词： Forest stand Scots pine Stand growth Urbanized environment Human footprint

Comparing the Structural Parameters of the Milky Way to Other Spiral Galaxies

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Research in Astronomy and Astrophysics 2024年第3期24卷 10-28页

作者： Jacob A.Guerrette aleksandr v.Mosenkov Dallin Spencer Zacory D.Shakespear Department of Physics and AstronomyN283 ESCBrigham Young University ProvoUT 84602USA

The structural parameters of a galaxy can be used to gain insight into its formation and evolution *** this paper,we strive to compare the Milky Way’s structural parameters to other,primarily edge-on,spiral galaxies in order to determine how our Galaxy measures up to the Local *** our comparison,we use the galaxy structural parameters gathered from a variety of literature sources in the optical and near-infrared wave *** compare the scale length,scale height,and disk flatness for both the thin and thick disks,the thick-to-thin disk mass ratio,the bulge-to-total luminosity ratio,and the mean pitch angle of the Milky Way’s spiral arms to those in other *** conclude that many of the Milky Way’s structural parameters are largely ordinary and typical of spiral galaxies in the Local Universe,though the Galaxy’s thick disk appears to be appreciably thinner and less extended than expected from zoom-in cosmological simulations of Milky Way-mass galaxies with a significant contribution of galaxy mergers involving satellite galaxies.

关键词： Galaxy disk-galaxies fundamental parameters-Galaxy structure

Unveiling the Nature of Polar-ring Galaxies from Deep Imaging

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Research in Astronomy and Astrophysics 2022年第11期22卷 34-50页

作者： aleksandr v.Mosenkov vladimir P.Reshetnikov Maria N.Skryabina Zacory Shakespear Department of Physics and Astronomy N283 ESCBrigham Young UniversityProvoUT 84602USA Central(Pulkovo)Astronomical Observatory Russian Academy of SciencesPulkovskoye Chaussee 65/1196140 St.PetersburgRussia St.Petersburg State University 7/9 Universitetskaya Nab.199034 St.PetersburgRussia

General structural properties and low surface brightness tidal features hold important clues to the formation of *** this paper,we study a sample of polar-ring galaxies(PRGs)based on optical imaging from the Sloan Digital Sky Survey Stripe 82 and other deep *** investigate the deepest images of candidates for PRGs to *** carry out photometric decomposition on the host galaxies and associated polar structures that allows us to derive the structural properties of both *** are able to detect very faint tidal structures around most PRGs in our *** several galaxies,we can directly observe the formation of the polar ring due to merging,which is manifested in debris of the victim galaxy and an arc-like polar structure made up of its *** a few cases,we can discern signs of tidal *** results obtained indicate that the gravitational interaction and merging of galaxies are the most plausible mechanisms for the formation of PRGs.

关键词： data analysis techniques:photometric galaxies:structure

Acoustic emission characterization of sliding wear under condition of direct and inverse transformations in lowtemperature degradation aged Y-TZP and Y-TZP-Al_2O_3

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Friction 2018年第3期6卷 323-340页

作者： Nikolai L SAvCHENKO Andrey v FILIPPOv Sergei Yu TARASOv Andrey I DMITRIEv Evgeny v SHILKO aleksandr S GRIGORIEv Institute of Strength Physics and Materials Science SB RAS National Research Tomsk Polytechnic University National Research Tomsk State University

In this research, results of the investigation of the sliding friction and wear of yttria-stabilized tetragonal zirconia polycrystalline(Y-TZP) and Y-TZP-Al_2O_3 samples preliminarily subjected to low-temperature degradation are reported. The investigation was carried out using a pin-on-disk tribometer with simultaneous recording of acoustic emission(AE) and vibration acceleration. The sliding wear process was found to be determined by dynamic direct and inverse Y-TZP transformations detected by monoclinic and tetragonal X-ray diffraction peak ratios. The AE signals generated under direct and inverse transformations can be used to characterize wear and friction mechanisms as well as direct and inversed sliding-induced phase transformations. The AE signal energy grows with the friction coefficient and the inverse transformation degree. Reduction of the AE signal energy indicates establishing the mild wear stage caused by effective stress-induced direct martensitic transformation. The AE signal median frequency increases in the case of lower friction. Numerical studies of wear subsurface fracture under conditions of stress-induced martensitic transformation were used to elucidate the role played by the phase transformation in Y-TZP and Y-TZP-Al_2O_3. Martensitic transformation in Y-TZP was described with use of the non-associated dilatant plasticity model. Simulation results particularly show that increase in the value of dilatancy coefficient from 0 to 0.2 is accompanied by 25%-30% reduce in characteristic length and penetration depth of sliding-induced subsurface cracks. As shown the AE may be an effective tool for in-situ monitoring the subsurface wear of materials experiencing both direct and inverse transformations.

关键词： zirconia transformation toughening low-temperature degradation friction acoustic emission numerical modeling movable cellular automata method

Nucleation of dislocations and twins in fcc nanocrystals: Dynamics of structural transformations

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Journal of Materials Science & Technology 2019年第1期35卷 201-206页

作者： aleksandr v.Korchuganov aleksandr N.Tyumentsev Konstantin P.Zolnikov Igor Yu.Litovchenko Dmitrij S.Kryzhevich Elazar Gutmanas Shouxin Li Zhongguang Wang Sergey G.Psakhie Institute of Strength Physics and Materials Science of Siberian Branch of Russian Academy of Sciences National Research Tomsk State University Technion–Israel Institute of Technology Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences

This paper reports on a molecular dynamics study of structural rearrangements in a copper nanocrystal during nucleation of plastic deformation under uniaxial tension. The study shows that the resulting nucleation of partial dislocations on the free surface and their glide occurs through local fcc→bcc→hcp transformations via consistent atomic displacements. We propose an atomic model for the generation of dislocations and twins based on local reversible fcc→bcc→fcc transformations, with the reverse one proceeding through an alternative system. The model gives an insight into possible causes and mechanisms of the generation of partial dislocations and mechanical twins in two and more adjacent planes of plastically deformed nanocrystals. The obtained data allow a better understanding of how plasticity is generated in nanostructured materials.

关键词： Lattice defects Dislocation Nanotwin Atomic model Molecular dynamics simulations

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

Functionality of a bicistronic construction containing HEXA and HEXB genes encoding β-hexosaminidase A for cell-mediated therapy of GM2 gangliosidoses

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Neural Regeneration Research 2022年第1期17卷 122-129页

作者： Alisa A.Shaimardanova Daria S.Chulpanova valeriya v.Solovyeva aleksandr M.Aimaletdinov Albert A.Rizvanov Institute of Fundamental Medicine and Biology Kazan Federal UniversityKazanRussia

Tay-Sachs disease and Sandhoff disease are severe hereditary neurodegenerative disorders caused by a deficiency ofβ-hexosaminidase A(HexA)enzyme,which results in the accumulation of GM2 gangliosides in the nervous system *** this work,we analyzed the efficacy and safety of cell-mediated gene therapy for Sandhoff disease and Sandhoff disease using a bicistronic lentiviral vector encoding cDNA of HexAα-andβ-subunit genes separated by the nucleotide sequence of a P2A peptide(HEXA-HEXB).The functionality of the bicistronic construct containing the HEXA-HEXB genetic cassette was analyzed in a culture of HEK293T cells and human umbilical cord blood mononuclear cells(hUCBMCs).Our results showed that the enzymatic activity of HexA in the conditioned medium harvested from genetically modified HEK293T-HEXA-HEXB and hUCBMCs-HEXA-HEXB was increased by 23 and 8 times,respectively,compared with the conditioned medium of native *** blot analysis showed that hUCBMCs-HEXA-HEXB secreted both completely separated HEXA and HEXB proteins,and an uncleaved protein containing HEXA+HEXB linked by the P2A *** injection of genetically modified hUCBMCs-HEXA-HEXB to laboratory Wistar rats was carried out,and the HexA enzymatic activity in the blood plasma of experimental animals,as well as the number of live cells of immune system organs(spleen,thymus,bone marrow,lymph nodes)were determined.A significant increase in the enzymatic activity of HexA in the blood plasma of laboratory rats on days 6 and 9(by 2.5 and 3 times,respectively)after the administration of hUCBMCsHEXA-HEXB was *** the same time,the number of live cells in the studied organs remained ***,the functionality of the bicistronic genetic construct encoding cDNA of the HEXA and HEXB genes separated by the nucleotide sequence of the P2A peptide was shown in vitro and in *** hypothesize that due to the natural ability of hUCBMCs to overcome biological barriers,such a strategy can rest

关键词： bicistronic vector cell-mediated gene therapy GM2 gangliosidosis P2A peptide Sandhoff disease Tay-Sachs disease umbilical cord blood mononuclear cells β-hexosaminidase

Kinetics and mechanism of the low-energy β-a phase transition of the second kind in 2,4-dinitroanisole

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Defence Technology（防务技术） 2024年第10期40卷 210-224页

作者： aleksandr v.Stankevich Nikolay A.Rasputin Anisa KhRudina Gennady L.Rusinov vera I.Filyakova valery N.Charushin I.Ya. Postovsky Institute of Organic Synthesis Ural Branch of the Russian Academy of Sciencesekaterinburg 620108russia Russian Federal Nuclear Center-Zababakhin All-Russia Research Institute of Technical Physics snezhinsk 456770russia Kazan National Research Technological University kazan 420015russia

In this work, comprehensive studies of 2,4-dinitroanisole(2,4DNAN) were carried out using powder thermorentgenography of the internal standard. The time of the complete polymorphic transition in the solid phase β→a in 2,4DNAN under various combinations of conditions has been determined. It has been established that, regardless of the season of manufacture of the substance, when it is stored for 8-9months, with a change in ambient temperature from minus 30℃ to plus 30℃, a complete polymorphic transition β→a occurs. When stored in conditions below minus 5℃, polymorphic transition does not occur. When stored in conditions above plus 30℃ in a closed container, polymorphic transition occurs within 3 weeks. The polymorphic transition is accompanied by a decrease in density by 1.3%-1.5% and an increase in melting temperature by 10-12℃, depending on the degree of purity of the starting substance. The activation energy of the molecular rearrangement was 68-70 k J/mol(16.5 ± 3 kcal/mol). The mechanism of polymorphic transition has been evaluated, which is presumably based on internal homodiffusion and energy transfer to the surface of the mass of powder particles and the product. The average activation energy of the polymorphic transition process was 110 ± 6.2 k J/mol(26.2 kcal/mol). In an open container, reactions proceed by a homogeneous mechanism, and in a closed container by a heterogeneous mechanism involving the gas phase.

关键词： Energetic materials Melt-castable 2,4-Dinitroanisole Polymorphic transition Kinetics Mechanism Homodiffusion Sublimation

Revealing the nature of optical activity in carbon dots produced from different chiral precursor molecules

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Light(Science & Applications) 2022年第5期11卷 855-867页

作者： Ananya Das Evgeny v.Kundelev Anna A.vedernikova Sergei A.Cherevkov Denis v.Danilov aleksandra v.Koroleva Evgeniy v.Zhizhin Anton N.Tsypkin aleksandr P.Litvin Alexander v.Baranov Anatoly v.Fedorov Elena v.Ushakova Andrey L.Rogach Center of Information Optical Technologies ITMO UniversitySaint Petersburg 197101Russia Research Park Saint Petersburg State UniversitySaint Petersburg 199034Russia Laboratory of Femtosecond Optics and Femtotechnology ITMO UniversitySaint Petersburg 197101Russia Laboratory of Quantum Processes and Measurements ITMO UniversitySaint Petersburg 197101Russia Department of Materials Science and Engineering and Centre for Functional Photonics(CFP)City University of Hong KongKowloonHong Kong SAR 999077China Shenzhen Research Institute City University of Hong KongShenzhen 518057China

Carbon dots(CDs)are light-emitting nanoparticles that show great promise for applications in biology and medicine due to the ease of fabrication,biocompatibility,and attractive optical *** chirality,on the other hand,is an intrinsic feature inherent in many objects in nature,and it can play an important role in the formation of artificial complexes based on CDs that are implemented for enantiomer recognition,site-specific bonding,*** employed a one-step hydrothermal synthesis to produce chiral CDs from the commonly used precursors citric acid and ethylenediamine together with a set of different chiral precursors,namely,L-isomers of cysteine,glutathione,phenylglycine,and *** resulting CDs consisted of O,N-doped(and also S-doped,in some cases)carbonized cores with surfaces rich in amide and hydroxyl groups;they exhibited high photoluminescence quantum yields reaching 57%,chiral optical signals in the Uv and visible spectral regions,and two-photon *** signals of CDs were rather complex and originated from a combination of the chiral precursors attached to the CD surface,hybridization of lower-energy levels of chiral chromophores formed within CDs,and intrinsic chirality of the CD *** DFT analysis,we showed how incorporation of the chiral precursors at the optical centers induced a strong response in their circular dichroism *** optical characteristics of these CDs,which can easily be dispersed in solvents of different polarities,remained stable during pH changes in the environment and after Uv exposure for more than 400 min,which opens a wide range of bio-applications.

关键词： properties chiral carbon

Negative thermal expansion in one-dimension of a new double sulfate AgHo(SO_(4))_(2)with isolated SO_4 tetrahedra

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Journal of Materials Science & Technology 2021年第17期76卷 111-121页

作者： Yuriy G.Denisenko victor v.Atuchin Maxim S.Molokeev Naizheng Wang Xingxing Jiang aleksandr S.aleksandrovsky Alexander S.Krylov aleksandr S.Oreshonkov Alexander E.Sedykh Svetlana S.volkova Zheshuai Lin Oleg v.Andreev Klaus Müller-Buschbaum Institute of Chemistry Tyumen State University.Tyumen625003Russia Institute of Inorganic and Analytical Chemistry Justus-Liebig-University of Giessen35392Giessen.Germany Department of General and Special Chemistry Industrial University of TyumenTyumen625000Russia Laboratory of Optical Materials and Structures Institute of Semiconductor PhysicsSB RASNovosibirsk630090Russia Laboratory of Semiconductor and Dielectric Materials Novosibirsk State UniversityNovosibirsk630090Russia Research and Development Department.Kemerovo State University Kemerovo650000Russia Laboratory of Crystal Physics Kirensky Institute of PhysicsFederal Research Center KSC SB RASKrasnoyarsk660036Russia Siberian Federal University Krasnoyarsk660041Russia Department of Physics Far Eastern State Transport UniversityKhabarovsk680021Russia Technical Institute of Physics and Chemistry Chinese Academy of SciencesBeijing100190China Laboratory of Coherent Optics Kirensky Institute of Physics.Federal Research Center KSC SB RASKrasnoyarsk660036Russia Institute of Nanotechnology Spectroscopy and Quantum ChemistrySiberian Federal UniversityKrasnoyarsk660041Russia Laboratory of Molecular Spectroscopy Kirensky Institute of PhysicsFederal Research Center KSC SB RASKrasnoyarsk660036Russia Center for Materials Research(LaMa) Justus-Liebig-University GiessenGiessen35392Germany University of the Chinese Academy of Sciences Beijing100049China Laboratory of the Chemistry of Rare Earth Compounds Institute of Solid State ChemistryUB RASEkaterinburg620137Russia

A double holmium-silver sulfate was obtained for the first *** temperature intervals for the formation and stability of the compound were determined by differential scanning *** crystal structure of AgHo(SO_(4))_(2)was determined by Rietveld *** X-ray diffraction(XRD)analysis showed that the compound crystallizes in the monoclinic syngony,space group P2_1/m,with the unit cell parameters a=4.71751(4)A,b=6.84940(6)A and c=9.89528(9)A,β=95.1466(4)·,v=318.448(5)A^(3),Z=2,R_B=1.55%,T=303 *** types of sulfate tetrahedra were found in the structure,which significantly affected the spectral properties in the infrared *** the temperature range of 143-703 K,a negative thermal expansion along the b direction accompanied by a positive thermal expansion along the a and c directions was *** was established that negative thermal expansion is the result of the deformation of sulfate tetrahedra,which is affected by the movement of holmium and silver *** excitation in the blue spectral range(457.9 nm)produces a luminescence in light blue(489 nm),green(545 nm)and red(654 nm)spectral ranges,and the latter two were of comparable intensity that is favorable for WLED *** observed luminescent band distribution is ascribed to the specific crystal field at Ho^(3+)ion sites rather than a variation of radiationless probability.

关键词： Sulfate Crystal structure Thermal expansion Raman Photoluminescence Band structure