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Negative thermal expansion in one-dimension of a new double sulfate AgHo(sO_(4))_(2)with isolated sO_4 tetrahedra

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

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Elucidating elusive quaternary selenide EuCeCuse3:synthesis,crystal structure,properties and theoretical studies

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Journal of Rare Earths 2024年第1期42卷 163-171,I0006页

作者： Maxim V.Grigoriev Anna V.Ruseikina Maxim s.Molokeev Vladimir A.Chernyshev aleksandr s.aleksandrovsky Alexander s.Krylov svetlana N.Krylova Nikolai P.shestakov Dmitriy A.Velikanov Alexander A.Garmonov Alexey V.Matigorov Evgeny A.Ostapchuk Thomas schleid Damir A.safin Laboratory of Theory and Optimization of Chemical and Technological Processes University of TyumenVolodarskogo Str.6625003TyumenRussian Federation Kirensky Institute of Physics Federal Research Center KSC SB RASAkademgorodok 50 Bld.38660036KrasnoyarskRussian Federation Department of Physics Far Eastern State Transport UniversitySerysheva Str.47680021KrasnoyarskRussian Federation Institute of Natural sciences and Mathematics Ural Federal University Named After the First President of Russia B.N.YeltsinMira Str.19620002EkaterinburgRussian Federation Department of Photonics and Laser Technology Siberian Federal UniversitySvobodnii Ave.79660079KrasnoyarskRussian Federation Institute of Physics and Technology University of TyumenVolodarskogo Str.6625003 TyumenRussian Federation Institute for Inorganic Chemistry University of StuttgartPfaffenwaldring 55D-70569StuttgartGermany scientific and Educational and Innovation Center for Chemical and Pharmaceutical Technologies Ural Federal University named after the First President of Russia B.N.YeltsinMira Str.19620002 EkaterinburgRussian Federation University of Tyumen Volodarskogo Str.6625003TyumenRussian Federation

We report on the novel heterometallic quaternary selenide EuCeCuse3,the fabrication of which has been a challenge until this *** structure of the reported selenide was elucidated from the powder X-ray diffraction data,which revealed the formation of EuCeCuse3with excellent yield(96.7%)accompanied with a minor fraction of Cese2(3.3%),and was best solved in orthorhombic space group Pnma with the BaLaCus3structural ***,the crystal structure of the title compound completes the row of the heterometallic quaternary selenides EuRECuse3(RE=La,Pr,Nd,sm,Eu,Gd,Tb,Dy,Ho,Er,Tm,Yb,Lu,Y),of which the cerium-based derivative exclusively belongs to the BaLaCus3structural *** distortion of the Cuse4polyhedron was compared for the whole series of EuRECuse3compounds using theτ4-descriptor for four coordinated ions,which revealed the highest degree of distortion for the Ce3+-containing selenide,followed by the La3+-based ***,the crystallographic and geometrical parameters of the reported selenide were discussed in comparison to the Ce3+-based sulfides srCeCus3and *** initio calculations of the crystal structure,a phonon spectrum and elastic constants for the crystal of EuCeCuse3were also *** types and wavenumbers of fundame ntal modes were determined and the involvement of ions participating in the phonon modes was *** experimental IR spectrum of the reported selenide was interpreted and found to be in agreement with the calculated *** experimental direct band gap of EuCeCuse3was measured to be 1.36 eV that is consistent with the concept of its origin due to interband transitions between orbitals emerging mainly from 4f(valence band)and 5d(conduction band)levels of the Eu2+*** dependence of the Young’s modulus on the direction demonstrates the anisotropy of the elastic properties,while the Vickers hardness for EuCeCuse3was calculated to be 5.2 ***,the title compound is paramagnetic above 4 K.

关键词： Quaternary selenide synthesis Crystal structure Ab initio calculations Magnetic measurements spectroscopy

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Changes in the growth of scots pine(Pinus sylvestris L.)stands in an urban environment in European Russia since 1862

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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

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Application of biostimulants for vegetative propagation of endangered Abies gracilis

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Journal of Forestry Research 2020年第4期31卷 1195-1199页

作者： Lev P.Trofimuk Pavel s.Kirillov aleksandr A.Egorov st.Petersburg state Forest Technical University Institutskii pereulok 5Saint-PetersburgRussia 194021 st.Petersburg state University University quay 7-9Saint-PetersburgRussia 199034

Abies gracilis Kom.(Pinaceae)is one of the rarest and endangered conifers in the Russian flora,which must be cultivated ex situ to ensure its *** of *** do not take root without *** used a selection of biostimulants,concentrations,and conditions of their use to significantly increase Abies gracilis rooting,and to accelerate the production of planting material,and to reduce rooting time to one *** tested 4 rooting systems:IBA,IBA with glucose and glycine,and original biostimulants(s-try and s-5).The original s-5 biostimulating system had the most balanced ratio of *** number of rooted samples increased 2.7 times and the length of roots increased 1.8 time when using s-5 as compared to IBA.s-try and s-5-original biostimulant systems were synthesized and collected in 2011 and 2014,respectively,and were tested in *** Forest Technical University.

关键词： Root formation Abies gracilis Biostimulant Planting Vegetative reproduction

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Carbon–Iron Microfibrous Material Produced by Thermal Treatment of self-rolled Poly(4-vinyl pyridine) Films Loaded by Fe_2O_3 Particles

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Journal of Materials science & Technology 2015年第9期31卷 881-887页

作者： Camelia Matei Ghimbeu aleksandr I.Egunov Andrey s.Ryzhikov Valeriy A.Luchnikov Institut de science des Matériaux de Mulhouse

Ensembles of freeze-dried self-rolled polymer micro-scrolls are explored as template media for produc- ing carbon-iron based composites with fibrous morphology. Polymer fibres impregnated with furfuryl alcohol and loaded with Fe2O3 particles, were thermally treated under inert atmosphere at 700 ℃ and subsequently analysed by scanning and transmission electron microscopy, X-ray diffraction, thermogravimetric analysis, and nitrogen adsorption. The resulting material has a micro-fibrous mor- phology and is basically composed of metallic Fe^0 and FeO particles, i.e., more than 98 wt% of the carbon/ iron-based composite mass. These particles are held together by amorphous porous carbon foam obtained by in-situ carbonization of the polymer/Fe2O3 composite with evacuation of carbon from the system via COx gases released by carbo-reduction of Fe2O3. The material has significant activity in the reaction of catalytic decomposition of hydrogen peroxide in water solutions.

关键词： Composite materialsPorous carbonPolymersIron particles

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Crystal structure and thermal expansion of perovskites containing uranium(VI) and rare-earth elements

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Journal of Rare Earths 2009年第1期27卷 4-11页

作者： aleksandr Knyazev Anna Ershova Nikolai Chernorukov Nizhny Novgorod state University

By the method of high-temperature reactions in solid phase, compounds with the general formula MⅡ（AⅢ2/3U1/3）O3（MⅡ=sr, AⅢ=sc, In;MⅡ=Ba, AⅢ=sc, In, Y, Nd-Lu） were *** structures（space groups Fm 3 m and Pnma） were refined by the Rietveld method and morphotropic transition in Ba（Ln2/3U1/3）O3 on the border of Gd-Tb was *** means of high-temperature X-ray diffraction, phase transitions were studied and thermal expansion coefficients were determined.

关键词： perovskite uranium X-ray diffraction Rietveld structure thermal expansion rare earths

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Photochemical degradation of nonylphenol in aqueous solution: The impact of pH and hydroxyl radical promoters

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Journal of Environmental sciences 2013年第7期25卷 1326-1330页

作者： aleksandr Dulov Niina Dulova Marina Trapido Department of Chemical Engineering Tallinn University of Technology

The degradation of nonylphenol （NP） in aqueous solution with UV, H202/UV, and Fenton/photo-Fenton processes was studied. The efficacy of direct and hydrogen peroxide photolysis proved to be dependent on the pH value. The addition of H202 to UV treatment improved NP degradation. The application of UV photolysis and the H202/UV system at pH 7 resulted in low pseudo first-order rate constants at 104 sec1 . In the experiments at elevated pH values the pseudo-first order rate constants increased to 103 sec1 . The efficacy of the Fenton process was lower in comparison with UV and hydrogen peroxide photolysis. The addition of UV irradiation to the H202/Fe2＋ system substantially improved NP degradation efficacy. In terms of performance, the photo-Fenton process was similar to the H202/UV process. The most favourable process for complete nonylphenol degradation considering both operational cost and treatment efficacy was H202/UV at pH 11 and 250 μmol/L H202 .

关键词： AOPs endocrine disrupting compound photo-Fenton process photolysis UVC radiation

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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

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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

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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

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