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Dissipation-induced instabilities and symmetry

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Acta Mechanica Sinica 2011年第1期27卷 2-6页

作者： oleg n.Kirillov Ferdinand Verhulst Dynamics and Vibrations Group Department of Mechanical EngineeringTechnical University of Darmstadt Hochschulstr.1 Mathematisch Instituut University of Utrecht

The paradox of destabilization of a conservative or non-conservative system by small dissipation,or Ziegler’s paradox（1952）,has stimulated a growing interest in the sensitivity of reversible and Hamiltonian systems with respect to dissipative *** the last decade it has been widely accepted that dissipation-induced instabilities are closely related to singularities arising on the stability boundary,associated with Whitney’s *** first explanation of Ziegler’s paradox was given（much earlier）by Oene Bottema in *** aspects of the mechanics and geometry of dissipation-induced instabilities with an application to rotor dynamics are discussed.

关键词： Dissipation-induced instabilities Destabilization paradox Ziegler pendulum Whitney umbrella

A class of high-mobility layered nanomaterials by design

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Journal of Materials Science & Technology 2023年第33期164卷 179-187页

作者： Dmitry V.Averyanov Ivan S.Sokolov oleg E.Parfenov Alexander n.Taldenkov oleg A.Kondratev Andrey M.Tokmachev Vyacheslav G.Storchak national Research Center “Kurchatov Institute” Kurchatov Sq.1Moscow 123182Russia

Design of materials with particular functional properties is indispensable albeit very *** and structural analogies can be helpful in this endeavor,especially when a particular combination of properties is sought *** aim is to bundle together 3 characteristics:high carrier mobility,magnetism,and scalability to nanomaterials in the form of a film–such a combination is particularly advantageous for ***,inspired by recent studies of MAl_(2)Si_(2)and related compounds,we develop magnetic EuAl_(2)Ge_(2)and non-magnetic SrAl_(2)Ge_(2)nanomaterials with high carrier *** syntheses employing sacrificial 2D templates result in epitaxial films of MAl_(2)Ge_(2)seamlessly integrated with *** syntheses are followed by a study of the atomic structure,magnetic and electron transport *** particular,the films demonstrate high carrier mobility,exceeding 10,000 cm^(2)V^(-1)s^(-1)in the case of EuAl_(2)Ge_(2),making the materials appealing for *** together,MAl_(2)Ge_(2)and MAl_(2)Si_(2)form a class of high-mobility layered nanomaterials.

关键词： High carrier mobility Magnetism SrAl_(2)Ge_(2) EuAl_(2)Ge_(2) Germanium

Glycine-nitrate combustion engineering of neodymium cobaltite nanocrystals

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Rare Metals 2021年第7期40卷 1778-1784页

作者： Ekaterina Alekseevna Tugova oleg nikolaevich Karpov new Inorganic Materials Laboratory Ioffe InstituteSaint-Petersburg 194021.Russia Department of Physical Chemistry Saint Petersburg Electrotechnical University“LETT”Saint-Petersburg 197376Russia

ndCoO_(3)nanocrystals formed via glycine-nitrate combustion method followed by heat treatment has been systematically *** of ndCoO_(3)nanocrystals with minimal size of 7-10 nm from X-ray amorphous combustion products has been elucidated to be a very rapid process,occurring at the temperature of 550-600℃for5-30 *** comparison of the minimum sizes of ndCoO_(3)crystallites obtained from the offered empirical relation dmin=lunit cell·n(where n is 7-12 and‘unit cellis elementary cell parameter)and the data determined on the basis of X-ray diffraction(XRD)and transmission electron microscopy(TEM)showed good *** existence of special nanoporous microstructure and spatial limitations prevent ndCoO_(3)particle *** kinetic equation based on Avrami-Erofeev nucleation model was offered to be correlated well with experimental data of fractional conversion(a)versus isothermal time(s).The apparent activation energy(Ea=(338±32)kJ)of formation of ndCoO_(3)nanocrystals from X-ray amorphous combustion products obtained in excess of oxidant followed by heat treatment at 550-600℃was determined.

关键词： Rare earths Perovskite Kinetics Mechanism Combustion synthesis nucleation

Transverse magnetoresistance peculiarities of thermoelectric Lu-doped Bi_2Te_3 compound due to strong electrical disorder

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Journal of Rare Earths 2019年第3期37卷 292-298页

作者： oleg Ivanov Maxim Yaprintsev Elena Danshina Belgorod State University Belgorod State Technological University named after V.G.Shukhov

The n-type thermoelectric Bi_(1.9)Lu_(0.1)Te_3 was prepared by microwave-solvothermal method and spark plasma sintering. The magnetic field and temperature dependences of transverse magneto resistance measured within temperature 2-200 K interval allow finding the peculiarities characteristic for strongly disordered and inhomogeneous semiconductors. The first peculiarity is due to appearance of linear-inmagnetic field contribution to the total magneto resistance reflected in a crossover from quadratic magnetoresistance at low magnetic fields to linear magneto resistance at high magnetic fields. The linear magnetoresistance can result from the Hall resistance picked up from macroscopically distorted current paths due to local variations in stoichiometry of the compound studied. The second peculiarity is that both linear magnetoresistance magnitude and crossover field are functions of carrier mobility which is in agreement with the Parish and Littlewood model developed for disordered and inhomogeneous semiconductors. An increase in the mobility due to a decrease in temperature is accompanied by an increase in the magnetoresistance magnitude and a decrease in the crossover field. Finally, the third peculiarity is related to the remarkable deviation of the total magnetoresistance measured at various temperatures from the Kohler's rule. Presence of strong inhomogeneity and disorder in the Bi_(1.9)Lu_(0.1)Te_3 structure concluded from the magnetoresistance peculiarities can be responsible for the remarkable reduction in the total thermal conductivity of this compound.

关键词： Bismuth telluride Linear positive magnetoresistance Semiconductors Thermoelectric material Carrier mobility Kohler’s rule

Long-period eclipsing binaries:towards the true mass-luminosity *** test sample,observations and data analysis

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Research in Astronomy and Astrophysics 2020年第8期20卷 169-176页

作者： Alexei Yu.Kniazev oleg Yu.Maikov Ivan Yu.Katkov Leonid n.Berdnikov South African Astronomical Observatory P.O.Box 9ObservatoryCape Town7935South Africa Southern African Large Telescope P.O.Box 9ObservatoryCape Town7935South Africa Sternberg Astronomical Institute Lomonosov Moscow State UniversityMoscow119992Russia Institute of Astronomy of RAS Moscow 119017Russia new York University Abu Dhabi PO Box 129188Abu DhabiUAE Center for Astro Particleand Planetary PhysicsNYU Abu DhabiPO Box 129188Abu DhabiUAE

The mass-luminosity relation is a fundamental law of *** have suggested that the currently used mass-luminosity relation is not correct for the M/M⊙>2.7 range of mass since it was created utilizing double-lined eclipsing binaries,where the components are synchronized and consequently change each other's evolutionary *** exclude this effect,we have started a project to study longperiod massive eclipsing binaries in order to construct radial velocity curves and determine masses for the *** outline our project and present the selected test sample together with the first HRS/SALT spectral observations and the software package,FITTInG BInARY STARS(FBS),that we developed for the analysis of our spectral *** the first result,we present the radial velocity curves and best-fit orbital elements for the two components of the FP Car binary system from our test sample.

关键词： stars:luminosity function mass function stars:binaries:spectroscopic

Genes associated with testicular germ cell tumors and testicular dysgenesis in patients with testicular microlithiasis

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Asian Journal of Andrology 2018年第6期20卷 593-599页

作者： Ilya S Dantsev Evgeniy V Ivkin Aleksey A Tryakin Dmitriy n Godlevski oleg Yu Latyshev Victoriya V Rudenko Dmitry S Mikhaylenko Vyacheslav B Chernykh Elena A Volodko Aleksey B Okulov oleg B Loran Marina V nemtsova Russian Medical Academy ef Postgraduate Education Moscow 123995Russia n.n.Blokhin Russian Cancer Research Center Moscow 115478Russia Research Centre of Medical Genetics Moscow 115478Russia M.Sechenov First Moscow State Medical University Moscow 119991Russia n.I.Pirogov Russian national Research Medical University Moscow 117997Russia.

Testicular microlithiasis （TM） is one of the symptoms of testicular dysgenesis syndrome （TDS）. TM is particularly interesting as an informative marker of testicular germ cell tumors （TGCTs）. KIT ligand gene （KITLG）, BCL2 antagonist/killer 1 （BAK1）, and sprouty RTK signaling antagonist 4 （SPRY4） genes are associated with a high risk of TGCTs, whereas bone morphogenetic protein 7 gene （BMP7）, transforming growth factor beta receptor 3 gene （TGFBR3）, and homeobox D cluster genes （HOXD） are related to TDS. Using polymerase chain reaction-restriction fragment length polymorphism （PCR-RFLP） analysis, we investigated allele and genotype frequencies for KITLG （rs995030, rs1508595）, SPRY4 （rs4624820, rs6897876）, BAK1 （rs210138）, BMP7 （rs388286）, TGFBR3 （rs12082710）, and HOXD （rs17198432） in 142 TGCT patients, 137 TM patients, and 153 fertile men （control group）. We found significant differences in the KITLG GG_rs995030 genotype in TM （P= 0.01） and TGCT patients （P = 0.0005） compared with the control. We also revealed strong associations between KITLGrs1508595 and TM （G allele, P = 0.003; GG genotype, P= 0.01） and between KITLG_rs1508595 and TGCTs （G allele, P-- 0.0001; GG genotype, P = 0.0007）. Moreover, there was a significant difference in BMP7_rs388286 between the TGCT group and the control （T allele, P = 0.00004; TT genotype, P = 0.00006） and between the TM group and the control （T allele, P= 0.04）. HOXDalso demonstrated a strong association with TGCTs （rs17198432 A allele, P = 0.0001; AA genotype, P = 0.001）. Furthermore, significant differences were found between the TGCT group and the control in the BAK1_rs210138 G allele （P= 0.03） and the GG genotype （P= 0.01）. KITLG and BMP7genes, associated with the development of TGCTs, may also be related to TM. In summary, the KITLG GG_rs995030, GG_rs1508595, BMP7 TT_rs388286, HOXD AA_rs17198432, and BAK1 GG_rs210138 genotypes were associated with a high risk of TGCT development.

关键词： associations genotype high risk testicular dysgenesis syndrome testicular microlithiasis

Semen microbiota and cytokines of healthy and infertile men

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Asian Journal of Andrology 2022年第4期24卷 353-358页

作者： oleg V Bukharin natalya B Perunova Elena V Ivanova Irina n Chaynikova Anastasia V Bekpergenova Taisiya A Bondarenko Michael D Kuzmin Institute of Cellular and Intracellular Symbiosis Ural Department of the Russian Academy of SciencesOrenburg Federal Research Center UD of RASOrenburg 460014Russia

In this study,we determined the levels of cytokine secretory inhibitors and the microbiota biofilms of semen from healthy and infertile subjects.A total of 118 clinical bacterial isolates were isolated and *** secretory inhibitors were determined based on the difference in cytokine content between the control and experimental samples of cell-free supernatants of isolated *** formation was studied by determining the adhesion of microorganisms to the surface of a 96-well sterile plate and expressed as the optical density at 630 nm(OD_(630)).Cell-free supernatants of Staphylococcus contained higher levels of secretory inhibitor of cytokines in conditionally healthy than in infertile *** contrast,in infertile men,the ability to reduce cytokine levels was more characteristic of Enterococcus and *** Staphylococcus,Corynebacterium,and Enterococcus isolated from infertile subjects showed a greater ability to form biofilms than the same bacteria isolated from healthy *** research is needed on this topic,since it is necessary to determine the relationships between decreased secretory inhibitors of cytokines,production of biofilms by bacteria in semen,and *** is likely that the ability of microorganisms to change the concentration of cytokines and increase the level of biofilm formation in semen may be associated with minimal impairments of fertilizing ability,which are not detected using other methods.

关键词： biofilms infertility microbiota secretory inhibitor of cytokines semen

Operating limits and features of direct air capture on K_(2)CO_(3)/ZrO_(2) composite sorbent

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Chinese Journal of Chemical Engineering 2022年第6期35卷 11-20页

作者： Vladimir S.Derevschikov Janna V.Veselovskaya Anton S.Shalygin Dmitry A.Yatsenko Andrey Z.Sheshkovas oleg n.Martyanov Boreskov Institute of Catalysis SB RAS Akademika Lavrentieva Av.5630090 NovosibirskRussia novosibirsk State University Pirogova Str.1630090 NovosibirskRussia

Potassium carbonate-based sorbents are prospective materials for direct air capture(DAC).In the present study,we examined and revealed the influence of the temperature swing adsorption(TSA)cycle conditions on the CO_(2) sorption properties of a novel aerogel-based K_(2)CO_(3)/ZrO_(2) sorbent in a DAC *** was shown that the humidity and temperature drastically affect the sorption dynamic and sorption capacity of the *** a temperature at the sorption stage was 29℃ and a water vapor pressure P_(H2O) in the feed air was 5.2 mbar(1 bar=105 Pa),the composite material demonstrated a stable CO_(2) sorption capacity of 3.4%(mass).An increase in sorption temperature leads to a continuous decrease in the CO_(2) absorption capacity reaching a value of 0.7%(mass)at T=80℃.The material showed the retention of a stable CO_(2) sorption capacity for many cycles at each temperature in the *** PH2O in the inlet air from 5.2 to 6.8 mbar leads to instability of CO_(2) sorption capacity which decreases in the course of 3 consecutive TSA cycles from 1.7%to 0.8%(mass)at T=29℃.A further increase in air humidity only facilitates the deterioration of the CO_(2) sorption capacity of the material.A possible explanation for this phenomenon could be the filling of the porous system of the sorbent with solid reaction products and an aqueous solution of potassium salts,which leads to a significant slowdown in the CO_(2) diffusion in the composite sorbent *** investigate the regeneration step of the TSA cycle in situ,the macro ATRFTIR(attenuated total reflection Fourier-transform infrared)spectroscopic imaging was applied for the first *** was shown that the migration of carbonate-containing species over the surface of sorbent occurs during the thermal regeneration stage of the TSA *** movement of the active component in the porous matrix of the sorbent can affect the sorption characteristics of the composite *** revealed features make it possible

关键词： Zirconia aerogel Potassium carbonate Carbon dioxide Direct air capture Fourier-transform infrared spectroscopic imaging

CaAl_(2)Si_(2)O_(8) polymorphs:Sensitive geothermometers and geospeedometers

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Geoscience Frontiers 2023年第1期14卷 33-45页

作者： Liudmila A.Gorelova oleg S.Vereshchagin Vladimir n.Bocharov Sergey V.Krivovichev Andrey A.Zolotarev Mikhail A.Rassomakhin Institute of Earth Sciences Saint Petersburg State UniversitySt.PetersburgRussia Centrefor Geo-Environmental Research and Modelling(Geomodel).Saint Petersburg State University St.PetersburgRussia Kola Science Centre ApatityMurmansk RegionRussia South Urals Federal Research Center of Mineralogy and Geoecology of UB RAS MiassRussia

Plagioclase is the major rock-forming mineral constituting the Earth's crust,whereas anorthite(CaAl_(2)Si_(2)O_(8))is a common minerals in lunar highlands crust,meteorites,possibly in some comets and on *** anorthite,two high-temperature polymorphs of CaAl_(2)Si_(2)O_(8)are known:dmisteinbergite and svyatoslavite,which are found in burnt coal dumps,meteorites and *** we present the results of detailed studies(quenching experiments,elemental analysis,Raman spectroscopy and in situ high temperature single crystal X-ray diffraction(up to 1000℃))on naturally co-occurring CaAl_(2)Si_(2)O_(8)polymorphs(anorthite,dmisteinbergite and svyatoslavite)from a burnt coal dump in Kopeisk,*** polymorphs were found in all natural samples and obtained upon heating of dmisteinbergite(unquenchableβ-dmisteinbergite and quenchable y-dmisteinbergite).It was shown that Ca coordination differs significantly in CaAl_(2)Si_(2)O_(8)polymorphs,resulting in a different capacity to host Ba and possibly other large ion lithophile *** our data on natural samples with the previously published data on natural and synthetic compounds,we propose a new scheme of CaAl_(2)Si_(2)O_(8)polymorphs *** results indicate that CaAl_(2)Si_(2)O_(8)polymorphs could be used for temperature estimations for both Earth and planetary sciences.

关键词： Feldspar Polymorphism Anorthite Dmisteinbergite Svyatoslavite CaAl_(2)Si_(2)O_(8)