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Design of self-healing PEO-based protective layers containing in-situ grown LDH loaded with inhibitor on the MA8 magnesium alloy

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Journal of Magnesium and Alloys 2023年第10期11卷 3688-3709页

作者： A.S.Gnedenkov S.L.Sinebryukhov A.D.Nomerovskii v.S.Filonina A.yu.Ustinov S.v.Gnedenkov Institute of Chemistry of FEB RAS 159 Pr.100-letiya VladivostokaVladivostok690022Russia

The high corrosion rate of magnesium and its alloys in chloride-containing solution significantly reduces the potential of this material for diverse ***,the formation of a smart protective coating was achieved in this work to prevent degradation of the MA8 magnesium alloy.A porous ceramic-like matrix was obtained on the material by plasma electrolytic oxidation(PEO).Further surface functionalization was performed using layered double hydroxides(LDH) served as nanocontainers for the corrosion *** methods of LDH intercalation with benzotriazole(BTA) were *** composition and morphology of the formed coating were studied using SEM-EDX analysis,XRD,XPS,and Raman *** corrosion behavior of the coated samples was evaluated using electrochemical impedance spectroscopy and potentiodynamic *** corrosion rate was estimated using volumetry and gravimetry *** formed composite coating provides the Mg alloy with the lowest corrosion activity(|Z|_(f)=0.1 Hz)=8.48·10^(5) Ω·cm^(2),I_(c)=1.4·10^(-8)A/cm^(2),P_(H)=0.21 mm/year) and improves the protective properties of the PEO-coated sample(|Z|_(f)=0.1 Hz)=8.37·10^(3) Ω·cm^(2),I_(c)=4.1·10^(-7)A/cm^(2),P_(H)=0.31 mm/year).The realization of the self-healing effect of the inhibitor-containing LDH/PEO-coated system was studied using localized electrochemical methods(SvET and SIET) with two artificial defects on the surface.A mechanism involving three stages for the active corrosion protection of the alloy was *** findings contribute to the follow-up work of developing modified LDH/PEO-based structures that promote the Mg alloy with high corrosion resistance,superior electrochemical performance for applications in various fields of industry and medicine.

关键词： Magnesium alloy Plasma electrolytic oxidation Layered double hydroxides Corrosion inhibitor Electrochemistry Corrosion rate

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

Study of laser beam scattering by inhomogeneous ensemble of red blood cells in a shear flow

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Journal of Innovative Optical Health Sciences 2015年第4期8卷 85-96页

作者： S.yu Nikitin A.E.Lugovtsov v.D.Ustinov M.D.Lin A.v.Priezzhev Physics Faculty Lomonosov Moscow State University Moscow Russia International Laser Center Lomonosov Moscow State University MoscowRussia Faculty of Computational Mathematics and Cybernetics Lomonosov Moscow State University Moscow Russia Faculty of Fundamental Medicine Lomonosov Moscow State University Moscow Russia

Laser elktacytometry is a technique widely used for measuring the deformability of red blood cells(erythrocytes)in blood samples in *** ektacytometer,a flow of highly diluted suspension of erythrocytes in variable shear stress conditions is iluninated with a laser beam to obtain a diffraction *** diffraction pattern provides information about the shapes(shear induced elongations)of the cells under *** paper is dedicated to developing the technique of laser ektacytometry s0 that it would enable one to measure the distrilbution of the erythrocytes in *** discuss the problem of calibration of laser elktacytometer and test a novel data processing algorithm allowing to determine the parameters of the distribution of ery-throcytes ***,we examined 12 specimens of blood of rats under the action of 4 shear *** of the data shows that in conditions of a limited range of digitizing the diffraction patterns,the measurement errors for the mean deformability,deform-ability scatter and the skewness of erythrocytes distribution in deformability by our method are respectively 15%,20%and 20%.

关键词： Laser ifractometry ektacytometry shear flow difraction pattern deformability of erythrocytes erythrocytes variance in shapes image analysis

Photoluminescence properties of Eu3+-doped MgAl2O4 nanoparticles in various surrounding media

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Journal of Rare Earths 2019年第8期37卷 806-811,I0001页

作者： I.E.Kolesnikov E.v.Golyeva E.v.Borisov E.yu Kolesnikov E.Lahderanta A.v.Kurochkin M.D.Mikhailov St.Petersburg State University St.PetersburgRussia Lappeenranta University of Technology LUT LappeenrantaFinland Peter the Great St.Petersburg Polytechnic University St.PetersburgRussia Scientific and Technological Institute of Optical Material Science VNTs S.I.Vavilov State Optical InstituteSt.PetersburgRussia volga State University of Technology Yoshkar-OlaRussia

Eu3+-doped MgAl2O4 nanoparticles were prepared by modified Pechini method.X-ray diffraction analysis shows pure tetragonal spinel phase without any *** average size of synthesized nanoparticles was determined to be about 50-60 nm using scanning electron microscopy and static light scattering *** and excitation spectra as well as lifetimes of MgAl2O4:Eu3+ nanophosphors were explored in surrounding media with different refractive *** medium does not affect luminescence bands position,whereas 5D0 lifetime monotonically decreases along with increase of medium refractive *** of surrounding media on radiative and nonradiative decay rates,which were calculated using 4f-4f intensity theory,was studied and *** factor of prepared nanoparticles is defined using both radiative and observed lifetimes.

关键词： Eu3+ Nanoparticles Filling factor Luminescence Lifetime Rare earths

Design of Mg-Zn-Si-Ca casting magnesium alloy with high thermal conductivity

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Journal of Magnesium and Alloys 2020年第1期8卷 184-191页

作者： v.E.Bazhenov A.v.Koltygin M.C.Sung S.H.Park A.yu.Titov v.A.Bautin S.v.Matveev M.v.Belov v.D.Belov K.v.Malyutin National University of Science and Technology“MISiS” Leninskiy pr.4Moscow 119049Russia LG Electronics Inc. Yeoui-daeroYeongdeungpo-gu.128LG Twin TowerSeoul 07336 Republic of Korea

Magnesium alloys are commonly used to produce lightweight *** most magnesium alloys exhibit low thermal conductivities,high thermal conductivities are needed for electronic *** this study,we attempted to develop new magnesium casting alloys with high thermal *** Mg-Zn-Si-Ca alloy compositions were chosen using CALPHAD(CALculation of PHAse Diagrams)calculations,and alloy samples were *** fluidity and hot-tearing resistance were *** results indicated that these properties were similar to those of AZ91 *** tests showed that high-pressure die casting could produce Mg-Zn-Si-Ca alloys possessing mechanical properties 1.5-3 times higher than those produced via sand *** alloy thermal conductivity was 126 W/mK at room *** corrosion rates of the as-cast samples in NaCl/water solutions were two times higher than that of AZ91.

关键词： Magnesium alloy Thermal conductivity Phase composition Corrosion rate Sand casting High-pressure die casting

Features of ^(90)Sr behavior in Crimean lakes with different salinity of their water environment

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Acta Geochimica 2023年第1期42卷 89-102页

作者： N.yu.Mirzoeva S.I.Arkhipova v.yu.Proskurnin O.N.Miroshnichenko I.N.Moseichenko A.O.Kovalevsky Institute of Biology of the Southern Seas of RAS SevastopolRussian Federation

The comparative study of technogenic ^(90)Sr behavior features in Crimea lakes’ ecosystems with different levels of salinity was carried out in *** sources of ^(90)Sr input were identified for all the studied lakes:the primary source concerned with atmospheric fallout immediately after the Chernobyl NPP accident and the secondary long-term input of this radionuclide by *** half-life of the ^(90)Sr concentration in the water of the hypers aline Lake Sasyk-Sivash was estimated to vary from 0.8 to 1.1 years after the closure of the North Crimean Canal(NCC).Biogeochemical processes in the lake under the absence of the secondary source of the radionuclide input were shown to decrease in the ^(90)Sr residence time in the water column by 131 *** brackish water bodies,a significant factor influencing the radionuclide concentration in ecosystems of lakes was the pH of their water,while for hypers aline lakes the level of water salinity was the main factor determining ^(90)Sr *** concentration of ^(90)Sr in bottom sediments of studied lakes depended mainly on this radionuclide concentration in a water *** ^(90)Sr distribution factors(Kd) for studied lakes’ bottom sediments varied in a range of n·10^(0)÷n·10^(2) for hypersaline lakes and of n·10^(1)÷n·10^(2) for lakes with brackish *** to the closure of the NCC,the ^(90)Sr redistribution took place in lake ecosystems only under the geochemical processes within the water bodies *** results obtained in this work are of particular importance as a starting point or a basis for further radioecological studies of the Crimean inland waters after the reopening of the NCC and the Dnieper waters re-entering the territory of Crimea in 2022after the 8 years of their absence.

关键词： ^(90)Sr Salt lakes Water Bottom sediments Chernobyl NPP accident Crimea

Stages and Fracture Mechanisms of Lamellar Pearlite of 100-m-Long Differentially Hardened Rails Under Long-Term Operation Conditions

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Acta Metallurgica Sinica(English Letters) 2018年第12期31卷 1356-1360页

作者： A.A.yuriev v.E.Gromov v.A.Grishunin yu.F.Ivanov R.S.Qin A.P.Semin LTD Evraz-Integrated West Siberian MetallurgicalCombine NovokuznetskRussia Siberian State Industrial University NovokuznetskRussia National Research Tomsk Polytechnic University TomskRussia Institute of High Current Electronics SD RAS TomskRussia School of Engineering and Innovation The Open UniversityWalton HallMilton Keynes MK 7 6AAUK

Using the methods of transmission electron microscopy, the carbide phase evolution in surface layers of the differentiallyquenched rails is studied after the passed tonnage of 691.8 million tons at the depth up to 10 mm along the central axis andfillet of rail head. The action of two mutual supplement mechanisms of steel carbide phase transformation in surface layersat rail operation is established：（1） cutting mechanism of cementite particles with the following departure in the volume offerrite grains or plates （in pearlite structure）; （2） cutting mechanism and following dissolution of cementite particles,transfer of carbon atoms on dislocations （in Cottrell atmospheres and dislocation cores）, transfer of carbon atoms bymoving dislocations into ferrite grains volume （or plates） with the following repeated formation of nanosized cementiteparticles. The first mechanism is accompanied by the change in linear sizes and morphology of carbide particles. Cementiteelement composition change is not essential. Carbide structure change can take place during the second mechanism.

关键词： Cementite Pearlite Fracture Rails Mechanisms Operation

Tectonometamorphic Cycles in Different Geodynamic Conditions

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Journal of Earth Science 2000年第4期19卷 11-19页

作者： Miller yu v Dufour MS Institute of Precambrian Geology and Geochronology Russian Academy of ScienceSt-Petersburg 199034Russia Geological Faculty St-Petersburg State University St-Petersburg 199034Russia

Formation and attenuation of crust thermal anomalies, accompanied by development of geological structures, are governed by special laws, together with metamorphism and other endogenic process, form tectonometamorphic cycle (TMC). Because of rock rheology under metamorphic conditions, the structures, concurring with metamorphism, reflect geodynamic conditions much more perfect than those of the structures of nonmetamorphosed rocks. For this reason, structural investigations open wide, sometimes unique, possibilities for geodynamic research into regional metamorphosed terrains. The TMC features under different geodynamic conditions are shown with examples of California (subduction), Himalaya and Junggar Alatau (collision), and Northwest environs of the White Sea (polycyclic development). The analysis of these units serves as basis of some general conclusions. TMC, the steady pattern of crust thermal anomalies manifestation, does not practically depend on peculiarities of metamorphism. At lower and middle crust levels, occur the high-temperature complete cycles that include following two stages. The first is represented by nappes and paragenes of parallel bedding flow, the second, by linear folds, domes and faults. At top levels of fold complexes display the low-temperature reduced cycles, expressed only by structures of the second stage. There are gradual transitions between the complete and reduced cycles. Thermal anomalies in the first stage of complete cycles devolop against the background of large horizontal displacements at contacts between interacting plates or are genetically connected with their gently sloping fault planes. Of all structural elements of the cycles, in compressional environments (nappes, linear folds, domes etc.), only the structures of the first stage of complete cycles can be considered as indications of plate tectonics. Presence of such structures at the most ancient supracrustal complexes point to existence of plate tectonics already at

关键词： complete and reduced tectonometamorphic cycles nappe parallel bedding flow schistosity linear fold dome.

Effect of acoustic pulses and EHF radiation on multipotent marrow stromal cells in tissue engineering constructs

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Journal of Innovative Optical Health Sciences 2017年第1期10卷 75-83页

作者： R.K.Chailakhyan v.I.yusupov yu.F.Gorskaya A.I.Kuralesova yu.v.Gerasimov A.P.Sviridov A.Kh.Tambiev N.N.vorobieva A.G.Grosheva v.v.Shishkova I.L.Moskvina v.N.Bagratashvili N.F.Gamaleya Research Institute of Epidemiology and Microbiology Ministry of Health of the Russian Federation 18 GamaleyiMoscow 123098Russia v.I.I'ichev Pacific Oceanological Institute Far-Eastern Division of Russian Academy of Sciences43 BaltiskayaVladivostok 690041Russia Institute on Laser and Information Technologies of Russian Academy of Sciences 2 PionerskayaTroitskMoscow 142190Russia Biological Faculty of Moscow State University 1-12 Leninskiye Gory MSUMoscow 119234Russia

In this paper,we studied the effects of physical factors,such as,acoustic pulses of laser-induced hydrodynamics(ALIH)and extremely-high frequencies(EHF)radiation,on the formation of heterotopic bone marrow organs.A suspension of precipitated bone marrow cells from CBA mice were exposed to ALIH pulses and EHF radiation separately and in their com bination tissue engineering constructs,presenting gelatin sponges 2 by 2 by 2 mm in size containing 10^(7)nucleated bone marrow cells,were exposed to physical factors and were implanted under the renal capsules of syngeneic *** newly formed hematopoietic organs were examined in three and five months later after *** five months old transplants were bigger in size than the three months old *** number of hematopoietic cells in the rest of the groups increased during this period by a factor from 3 to 10,the increase being as high as 20-fold in the:ALH+EHF *** concentration of multipotent stromal cells(MSCs)was in the EHF+ALIH,and minimal concentration was in the ALIH+*** accumulation rate of bone capsule weight was highest for the transplants of EHF+ALIH and ALIH-sponge groups during the first three *** data showed that the combined impact of the EHF+ALIH on MSCs is the most effective for the formation of bone marrow transplantation.

关键词： Multipotent stromal cells heterotopic transplantation extremely high frequency radiation laser-induced hydrodynamics acoustic pulses.