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Effects of small additions of Zn on the microstructure, mechanical properties and corrosion resistance of WE43B Mg alloys

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International Journal of Minerals,Metallurgy and Materials 2019年第7期26卷 858-868页

作者： A.v. Koltygin v.E. Bazhenov R.S. Khasenova A.A. Komissarov A.I. Bazlov v.A. Bautin Foundry Department National University of Science and Technology “MISiS” Moscow 119049 Russia Laboratory of Hybrid Nanostructured Materials National University of Science and Technology “MISiS” Moscow 119049 Russia Laboratory of Advanced Green Materials National University of Science and Technology “MISiS” Moscow 119049 Russia Department of Metallurgy Steel New Production Technologies and Protection of Metals National University of Science and Technology “MISiS” Moscow 119049 Russia

Zn is a commonly used alloying element for Mg alloys owing to its beneficial effects on mechanical properties. To improve the mechanical and corrosion properties of WE43B Mg alloys, the effects of 0–0.7wt% Zn addition on the microstructure and properties of sample alloys were investigated. Addition of Zn to as-cast WE43B alloy promoted the formation of the Mg12Nd phase;by contrast, after T6 heat treatment, the phase composition of WE43B alloys with and without Zn addition remained mostly the same. A long-period stacking ordered phase was predicted by CALPHAD calculation, but this phase was not observed in either the as-cast or heat-treated Zn-containing WE43B alloys. The optimum temperature and duration of T6 heat treatment were obtained using CALPHAD calculations and hardness measurements. Addition of Zn resulted in a slight reduction in the average grain size of the as-cast and T6 heat-treated WE43B alloys and endowed them with increased corrosion resistance with little effect on their mechanical properties.

关键词： magnesium alloys corrosion resistance mechanical properties Zn addition

Influence of alkali metal doping on surface properties and catalytic activity/selectivity of CaO catalysts in oxidative coupling of methane

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Journal of Natural Gas Chemistry 2008年第4期17卷 313-320页

作者： v.H.Rane S.T.Chaudhari v.R.Choudhary Chemical Engineering and Process Development Division National Chemical Laboratory

Surface properties （viz. surface area, basicity/base strength distribution, and crystal phases） of alkali metal doped CaO （alkali metal/Ca= 0.1 and 0.4） catalysts and their catalytic activity/selectivity in oxidative coupling of methane （OCM） to higher hydrocarbons at different reaction conditions （viz. temperature, 700 and 750 ℃; CH4/O2 ratio, 4.0 and 8.0 and space velocity, 5140-20550 cm^3 ·g^-1·h^-1） have been investigated. The influence of catalyst calcination temperature on the activity/selectivity has also been investigated. The surface properties （viz. surface area, basicity/base strength distribution） and catalytic activity/selectivity of the alkali metal doped CaO catalysts are strongly influenced by the alkali metal promoter and its concentration in the alkali metal doped CaO catalysts. An addition of alkali metal promoter to CaO results in a large decrease in the surface area but a large increase in the surface basicity （strong basic sites） and the C2＋ selectivity and yield of the catalysts in the OCM process. The activity and selectivity are strongly influenced by the catalyst calcination temperature. No direct relationship between surface basicity and catalytic activity/selectivity has been observed. Among the alkali metal doped CaO catalysts, Na-CaO （Na/Ca = 0.1, before calcination） catalyst （calcined at 750 ℃）, showed best performance （C2＋ selectivity of 68.8% with 24.7% methane conversion）, whereas the poorest performance was shown by the Rb-CaO catalyst in the OCM process.

关键词： oxidative coupling of methane alkali metal doped CaO catalysts basicity/base strength distribution catalytic activity/selectivity

SCIENTIFIC PRINCIPLES FOR MODIFICATION OF WATER-SOLUBLE POLYMERS. FORMATION OF MACROMOLECULAR COMPLEXES

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Chinese Journal of Polymer Science 1998年第3期16卷 268-278页

作者： PAUTOv v.D. ANUFRIEvA E.v. KRAKOvYAK M.G. Institute of Macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 RussiaInstitute of Macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 RussiaInstitute of Macromolecular Compounds RAS Bolshoy pr. 31 St. Petersburg 199004 Russia

The study of nanosecond dynamics of macromolecules with the lumines-cent methods make it possible to investigate the formation and functioning of polymericcomplexes, polymeric conjugates and macromolecular metal complexes, which are widelyused for solving many practical tasks. The nanosecond dynamics of macromolecules are ahighly sensitive indicator of interpolymer complexes (IPC) formation. It enables us to solvethe problems of studying IPC formation and stability and to investigate the interpolymerreactions of exchange and substitution. The investigation of changes in the rotational mo-bility of globular protein molecules as a whole makes it possible to determine the complexcomposition and its stability, and to control the course of polymer-protein conjugate forma-tion reaction. The nanosecond dynamics of polymers interacting with surfacants' ions (S)are the sensitive indicator of the S-polymer complex formation. A method for determin-ing the equilibrium constants of the S-polymer complex formation was developed on thebasis of the study of polymer chains mobility. It is established that nanosecond dynamicsinfluences the course of chemical reactions in polymer chains. Moreover, the marked effectof the nanosecond dynamics is also revealed in the study of photophysical processes (theformation of excimers and energy migration of electron excitation) in polymers with pho-toactive groups. It was found that the efficiency of both processes increases with increasingthe mobility of side chains, the carriers of photoactive groups.

关键词： Modification of water-soluble polymers Formation of complexes

Interstitialcy theory of condensed matter states and its application to non-crystalline metallic materials

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Chinese Physics B 2017年第1期26卷 20-31页

作者： v A Khonik Department of General Physics State Pedagogical University Voronezh 394043 Russia

A comprehensive review of a novel promising framework for the understanding of non-crystalline metallic materials, i.e., interstitialcy theory of condensed matter states（ITCM）, is presented. The background of the ITCM and its basic results for equilibrium/supercooled liquids and glasses are given. It is emphasized that the ITCM provides a new consistent, clear, and testable approach, which uncovers the generic relationship between the properties of the maternal crystal,equilibrium/supercooled liquid and glass obtained by melt quenching.

关键词： liquids and glasses interstitialcy theory shear modulus relaxation

Numerical 3D Model of viscous Turbulent Flow in One Stage Gas Turbine and Its Experimental validation

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Journal of Thermal Science 2005年第2期14卷 136-141页

作者： Yu.v.STARODUBTSEv I.G.GOGOLEv v.G.SOLODOv National Technical University "KhADI" Ukraine Briansk State Technical University <BITM> RussiaNational Technical University "KhADI" Ukraine

The paper describes 3D numerical Reynolds Averaged Navier-Stokes (RANS) model and approximate sector approach for viscous turbulent flow through flow path of one stage axial supercharge gas turbine of marine diesel engine. Computational data are tested by comparison with experimental data. The back step flow path opening and tip clearance jet are taken into *** approach could be applied for variety of turbine theory and design tasks: for offer optimal design in order to minimize kinetic energy stage losses; for solution of partial supply problem; for analysis of flow pattern in near extraction stages; for estimation of rotational frequency variable forces on blades; for sector vane adjustment (with thin leading edges mainly), for direct flow modeling in the turbine etc. The development of this work could be seen in the direction of unsteady stage model application.

关键词： viscous turbulent flow one stage gas turbine tip leakage flow secondary flow.

Fluctuating fine-scale spatial genetic structure in the common shrews (Eulipotyphla, Mammalia)

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Integrative Zoology 2023年第3期18卷 469-492页

作者： Nikolay A.SHCHIPANOv Artem v.ARTAMONOv Sergey v.TITOv Svetlana v.PAvLOvA A.N.Severtsov Institute of Ecology and Evolution Russian Academy of SciencesMoscowRussia Department of Zoology and Ecology Penza State UniversityPenzaRussia

The spatial genetic structure is a topical issue in the studies of various aspects of ecology and *** the multilocus autocorrelation method with hypervariable microsatellite genetic markers,we investigated aﬁne-scale pattern of genetic structure in 5 local populations of the common shrew Sorex araneus separated by distances of 300–1000 m(the Moscow chromosomal race).Spatial genetic autocorrelation analysis based on 5 microsatellite loci(expected heterozygosity>0.79)with 90 alleles revealed a consistent pattern of signiﬁcant positive genetic *** testing the autocorrelation at multiple scales from 25 to 500 m,we found that positive spatial genetic structure is detectable in distance classes ofvely correlated with a higher ratio of nonresident individuals to residents’activity(number of captures).In contrast to nonresident animals,the residents demonstrated prominent genetic *** difference(FST)between the populations was signiﬁcant(0.016–0.051)and comparable with that between populations of different races analyzed previously(0.016–0.038).FST was not associated with geographic *** demographic patterns allowed us to propose a scheme of genetic-structure dynamics involving periodic appearance of more related local groups and renewal of allelic proﬁles fromаcommon pool where the alleles are *** scheme predictsﬂuctuating genetic structure and random similar differences among local populations.

关键词： demographic pattern geneﬂow microsatellite spatial autocorrelation

Nonlinear dynamics of MEMS turning fork gyroscope

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Science China(Technological Sciences) 2011年第5期54卷 1078-1083页

作者： Yu. G. MARTYNENKO I. v. MERKURYEv v. v. PODALKOv Institute of Mechanics Lomonosov Moscow State University Moscow Power Engineering Institute (Technical University)

Accuracy improvement of MEMS gyros requires not only microelectronic development but also the investigations of th mathematical model of sensitive element dynamics. In the present paper, we study the errors of the vibrating microgyroscop which arise because of nonlinear dynamics of a sensitive element. A MEMS tuning fork gyroscope with elastic rods is consid ered. Nonlinear differential equations of bending vibrations of sensitive element on the moving basis are derived. Free nonlin ear vibrations of gyroscopes as the flexible rod are studied. Nonlinear dynamics of gyroscope on the moving basis are investi gated by asymptotic two scales method. Sensitive element frequencies split on two frequencies resulted from slowly changin angular velocity are taken into account in the equations of zero approximation. The differential equations for slowly changin amplitudes and phases of two normal waves of the oscillations measured by capacitor gauges and an electronic contour of th device are obtained from the equations of the first approximation.

关键词： control of gyro oscillations split of frequencies identification averaging method two scales method stability

Processes underlying the laser photochromic effect in colloidal plasmonic nanoparticle aggregates

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Chinese Physics B 2020年第3期29卷 412-419页

作者： A E Ershov v S Gerasimov I L Isaev A P Gavrilyuk S v Karpov Institute of Computational Modeling SB RAS 660036KrasnoyarskRussia Siberian Federal University Krasnoyarsk660041Russia Kirensky Institute of Physics Federal Research Center KSC SB RAS660036KrasnoyarskRussia Siberian State University of Science and Technology Krasnoyarsk 660014Russia

We have studied the dynamic and static processes occurring in disordered multiparticle colloidal Ag aggregates with natural structure and affecting their plasmonic absorption spectra under pico-and nanosecond pulsed laser radiations, as well as the physical origin responsible for these processes. We have shown that depending on the duration of the laser pulse,the mechanisms of laser modification of such aggregates can be associated both with changes in the resonant properties of the particles due to their heating and melting(picosecond irradiation mode) and with the particle shifts in the resonant domains of the aggregates(nanosecond pulses) which depend on the wavelength, intensity, and polarization of the *** mechanisms result in formation of a narrow dip in the plasmonic absorption spectrum of the aggregates near the laser radiation wavelength and affect the shape and position of the dip. The effect of polydispersity of nanoparticle aggregates on laser photochromic reaction has been studied.

关键词： nanoparticle surface plasmon resonance photochromic process pulsed laser radiation

Stability of Macroscopic Binary Systems

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Communications in Theoretical Physics 2019年第11期71卷 1335-1340页

作者： G.G.Adamian N.v.Antonenko H.Lenske v.v.Sargsyan Joint Institu te for Nuclear Research 141980 DubnaRussia Ins titut fur Theore tische Physik der Jus tus-Liebig—Uni versit Nt D-35392 GiessenGermany

The Darwin instability effect in the binary systems(di-planets, di-stars, and di-galaxies) is analyzed within the model based on the Regge-like laws. All possible binary stars are found satisfying the Darwin instability condition that requires to search for other mechanism triggering the merger of the contact binary objects. New analytical formulas are obtained for the orbital rotation period and the relative distance between components of the binary system. The decreasing and increasing periods as functions of mass asymmetry are related, respectively, with the non-overlapping and overlapping stage of the binary object evolution.

关键词： Regge laws binary stars and galaxies Darwin instability effect