检索结果-南通市图书馆

International Journal of Coal Science & Technology 2022年第1期9卷 71-83页

作者： Nikita Popov Igor Chekryzhov Irina Tarasenko Sergery Kasatkin Aleksei Kholodov Far East Geological Institute feb ras VladivostokRussian Federation

There are known brown coal deposits in Primorsky Krai(Russian Federation),where coals contain rare elements(Ge,U,REE,etc.)up to industrial *** of the known metalliferous coals is the Rakovka coal-bearing depression,located on the southern edge of the Khanka(Prikhankaiskaya)Lowland,with an area of about 70 ***-metal granites with a developed weathering crust are spread in its basement and *** structural conditions forming the depression were studied using measurements of orientations of structural elements(layering,contacts,veins,and dikes)with regard to kinematic conditions of *** coal and host rocks were sampled in sections in the cross strike of the coal *** and dikes cutting them were sampled by separate rock chip *** chemical composition and element content were determined for all *** was found that the adjacent rocks played a major role in the formation of the Rakovka rare-metal-coal *** rare-elements enrichment is not associated with active tectonics,faults,and hydrothermal sources,as was previously ***,it was caused by the hydrogenic and clastogenic removal of these metals from the weathering crust of granites of the depression's flanks and argillated basite dikes cutting the *** hydrogenic nature of the anomalous accumulation of U in sorbed form on organic matter of coals is confirmed by the predominant enrichment of low-ash *** earth elements entered coal seams both in mineral and dissolved forms.A model of REE and uranium input into the coal-bearing sediments of the Rakovka depression was proposed.

关键词： REE Rare metal-coal deposit Accumulation pattern Tectonics

Smart composite antibacterial coatings with active corrosion protection of magnesium alloys

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第12期10卷 3589-3611页

作者： A.S.Gnedenkov S.L.Sinebryukhov V.S.Filonina N.G.Plekhova S.V.Gnedenkov Institute of Chemistry of feb ras 159 Pr.100-letiya VladivostokaVladivostok690022Russia

A new method of the formation of composite coatings with the function of active corrosion protection of magnesium alloys was developed using the plasma electrolytic oxidation(PEO) method. Susceptibility of PEO-layers to pitting formation was evaluated using localized electrochemical methods(SVET/SIET). The morphological features and electrochemical properties of composite coatings were studied using SEM/EDX, XRD, micro-Raman spectroscopy and EIS/PDP measurements, respectively. The effect of surface layers impregnation with corrosion inhibitor on their protective properties in a corrosive environment was established. Additional protection was achieved using controllable coating pore sealing with polymer. It was found that the polymer treatment of the PEO-layer does not reduce the inhibitor’s efficiency. The formed protective composite inhibitor-and-polymer-containing layers decrease the corrosion current density of a magnesium alloy in a 3 wt.% Na Cl solution to three orders of magnitude. This predetermines the prospect of new smart coatings formation that significantly expand the field of application of electrochemically active materials. The mechanism of smart composite coating corrosion degradation was established. The antibacterial activity of the inhibitor-containing coatings against S. aureus methicillin-resistant strain was proved using the in vitro model. These protective layers are promising for reducing the incidence of implant-associated infections.

关键词： Magnesium alloy Plasma electrolytic oxidation Corrosion inhibitor Self-healing Protective coatings

The detailed corrosion performance of bioresorbable Mg-0.8Ca alloy in physiological solutions

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2022年第5期10卷 1326-1350页

作者： A.S.Gnedenkov S.L.Sinebryukhov V.S.Filonina V.S.Egorkin A.Yu.Ustinov V.I.Sergienko S.V.Gnedenkov Institute of Chemistry of feb ras 159 Pr.100-letiya VladivostokaVladivostok690022Russia

The electrochemical behaviour of biodegradable magnesium alloy Mg-0.8Ca was evaluated in a mammalian cell culture medium(MEM)and Na Cl solutions(0.9 wt.%, 0.3 wt.%) using traditional(EIS, PDP, OCP) and local scanning electrochemical(SVET, SIET with p H-selective microelectrode) methods at the micro-and meso-level. Corrosion rates of samples in two different media were determined using weight loss tests. The influence of testing media components, alloy composition and microstructure on the material’s degradation process was *** SVET/SIET test parameters were optimized for in vitro investigation of the bioresorbable material surface. The mechanism of the alloy’s bioresorption was suggested. The effect of microsized phases on the corrosion behaviour of the alloy was proved using complementary in situ monitoring and SKPFM measurements. The rapid degradation rate of the alloy is related to the presence of local microgalvanic cells formed by cathodic α-magnesium matrix and anodic Mg_(2)Ca phase. The highest corrosion activity was revealed in the first 12 min of sample exposure to MEM, followed by stabilization of corrosion process due to the material’s passivation. Using SEM-EDX analysis, micro-Raman spectroscopy and XPS analysis the composition of the corrosion products was determined. Degradation in MEM proceeds with a formation of magnesium-and-carbonate substituted hydroxyapatite-containing film on the sample’s surface. The low possibility of application of Mg-0.8Ca alloy without coating protection in implant surgery was highlighted.

关键词： Magnesium-calcium alloy Biodegradation Corrosion rate Electrochemistry Weight loss Minimum essential medium

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

在线全文

学校读者我要写书评

暂无评论

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

Carboxylates as green corrosion inhibitors of magnesium alloy for biomedical application

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2024年第7期12卷 2909-2936页

作者： A.S.Gnedenkov S.L.Sinebryukhov A.D.Nomerovskii V.S.Marchenko A.Yu.Ustinov S.V.Gnedenkov Institute of Chemistry of feb ras 159 Pr.100-letiya VladivostokaVladivostok 690022Russia

The efficiency of the green inhibitors(sodium salts of fumarate,glycolate and gluconate)in suppressing corrosion of the structural MA8 magnesium alloy(Mg–Mn–Ce)and the biomedical Mg–0.8Ca alloy was studied using the hydrogen evolution measurements,mass loss test,EIS,PDP,SVET/*** analysis of the morphology,chemical composition,and growth kinetic of corrosion films formed in 0.9 wt%NaCl solution with and without corrosion inhibitors was carried *** most compact surface film with the smallest thickness was formed in a saline solution with sodium *** Mg alloy samples exhibited the highest polarization resistance,the lowest localized electrochemical activity,and the lowest corrosion rate in saline with the addition of sodium fumarate and sodium *** efficiency of the applied inhibitors was up to 81%.The model of the corrosion mechanism based on the sorption of molecules of organic inhibitors is *** results show the high compatibility of the used inhibitors with the calcium-phosphate PEO-matrix,indicating the possibility of forming a self-healing coating by means of these active substances.

关键词： Magnesium and its alloys Organic inhibitor Electrochemical behavior PEO-coatin Bioresorbable implant Degradation mechanism

Low-Frequency Hydroacoustic Experiments on the Shelf Using the Data of Geoacoustic Sediment Model

在线全文

学校读者我要写书评

暂无评论

Chinese Physics Letters 2014年第12期31卷 66-69页

作者： SAMCHENKO A. N. KOSHELEVA A.V. SHVYREV A. N. PIVOVAROV A. A. Il'icheve's Pacific Oceanological Institute (POI) feb ras Vladivostok 690041 Russia

Acoustic and seismoacoustic methods have become the most perspective and intensely developed meth- ods in the research of dynamic processes and inho- mogeneities in shallow water. Seismoacoustic moni- toring allows one to draw conclusions about the pres- ence of different inhomogeneities in the water environ- ment and to identify various dynamic processes in the oceanic shelf zone. Studies of the propagation of hy- droacoustic signals of different frequencies and config- urations are widely discussed in scientific publications in Russia, China and the United States Solutions to inversion problems in acoustics, the con- struction of geoacoustic models and research of low- frequency acoustic signals with respect to the absorb- ing bottom are without any doubt at the forefront of underwater acoustics.

关键词： UNDERWATER acoustics SEDIMENTS (Geology) ACOUSTIC signal processing WATER CONTINENTAL shelf MATHEMATICAL models

Electrochemical synthesis of boron-containing coatings on Mg alloy for thermal neutron shielding

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第10期11卷 3779-3789页

作者： K.V.Nadaraia S.N.Suchkov N.S.Markin I.M.Imshinetskiy S.I.Ivannikov D.V.Mashtalyar A.Yu.Ustinov S.L.Sinebryukhov S.V.Gnedenkov Institute of Chemistry feb ras 159 Pr.100-Letiya VladivostokaVladivostok 690022Russia

The work provides the results of the one-step formation of boron-containing coatings on an Mg–Mn–Ce alloy by plasma electrolytic oxidation. The results of studies of the composition, structure and morphology of heteroxide coatings are presented. It was established that the boron is contained in the coating mainly in the form of B or B_(2)O_(3). The introduction of B changes the color of coatings, and also helps to increase their porosity. The method of determining the full cross section of the interaction of thermal neutron absorption efficiency by samples material using the installation of neutron-activation analysis based on ^(252)Cf was developed. It was shown that the introduction of boron into the formed coatings allows to increase the macroscopic cross-section of the interaction of samples with thermal neutrons by 3.8 times. This effect opens the potential for the use of synthesized material in the field of nuclear technologies and aerospace industry.

关键词： Plasma electrolytic oxidation Boron Neutron capture Neutron shielding Protective coatings

Hydroxyapatite-containing PEO-coating design for biodegradable Mg-0.8Ca alloy: Formation and corrosion behaviour

在线全文

学校读者我要写书评

暂无评论

Journal of Magnesium and Alloys 2023年第12期11卷 4468-4484页

作者： A.S.Gnedenkov S.L.Sinebryukhov V.S.Filonina S.V.Gnedenkov Institute of Chemistry of feb ras 159 Pr.100-letiya VladivostokaVladivostok690022Russian Federation

In this study, the biocompatible protective coating was formed using plasma electrolytic oxidation(PEO) on bioresorbable Mg-0.8Ca alloy. The composition of the formed coating was studied using XRD, SEM-EDX analysis, and micro-Raman spectroscopy. The uniform distribution of hydroxyapatite over the thickness of protective PEO-layer was established. Using traditional(EIS, PDP, OCP) and local scanning electrochemical methods(SVET, SIET with H^(+)-selective microelectrode), the level of protective properties of PEO-layer in a biological environment(mammalian cell culture medium, MEM) was determined. It was established that modification of Mg-0.8Ca alloy surface by PEO contributes to a significant increase in the corrosion resistance of the surface layer, making it possible to control the process of material‘s biodegradation. The maximum local electrochemical activity was recorded after 72 h of testing, while for the uncoated sample,intense corrosion degradation was recorded in the first 12 min of exposure to the cell culture medium. Formation of the PEO-coating results in a twofold decrease in the corrosion current density(2.8·10^(-6)A cm^(-2)) and an increase in the impedance modulus measured at a low frequency(1.7·10^(4)Ω cm^(2)) in comparison with the uncoated material(9.5·10^(-6)A cm^(-2);8.1·10^(3)Ω cm^(2)). The mechanism of material bioresorption was established and a model for biodegradation process of Mg-0.8Ca alloy with hydroxyapatite-containing PEO-coating in MEM was proposed. Analysis of these results and comparing with others obtained by various scientific groups indicate the prospects for application of biocompatible PEO-coating on Mg-Ca alloy in implant surgery.

关键词： Magnesium-calcium alloy Biodegradation Implant surgery Plasma electrolytic oxidation Electrochemistry Minimum essential medium Hydroxyapatite

在线全文

学校读者我要写书评

暂无评论

萨哈林岛舞蛛属一新种记述(英文)

动物分类学报 2013年第2期38卷 267-271页

作者： Mikhail M.Omelko Yuri M.Marusik Seppo Koponen gornotaezhnaya station feb ras Far Eastern Federal University Institute for Biological Problems of the North Zoological Museum University of Turku

记述了采自萨哈林岛1新种,Alopecosa ***.,2♂♂,新种与solivaga种团近似。

关键词：狼蛛科俄罗斯远东新种萨哈林岛

Moving of a submarine under an ice cover in fluid of finite depth

在线全文

学校读者我要写书评

暂无评论

Journal of Hydrodynamics 2019年第3期31卷 562-569页

作者： Alexandra V. Pogorelova Vitali L. Zemlyak Victor M. Kozin Sholom-A leichem Priamursky State University Birobidzhan Russia Institute of Machining and Metallurgy feb ras Komsomolsk-na-Amure Russia

The influence of a basin depth on ice cover deflections, when a submarine moves under it in fluid, is experimentally and theoretically analyzed. For a theoretical research the ice cover is modelled by an elastic floating plate, and the submarine is modelled by a source-sink system in a fluid flow. The problem is solved by means of asymptotic analysis and integral transformations. The experimental study is conducted with submarine models in the pool with the sizes L*B*H= 10m*3m*lm . The ice cover for experiments is modelled in two ways. The first way is the thin ice plate received by freezing of the surface layer of water at low temperatures. In the second case the rubber sheet floating on a reservoir surface is used. The special velocity (the velocity at which maximum values of the wave height are reached) is analyzed. It is obtained that the decrease of the basin depth leads to decrease of the special speed. For small speeds (less than the special speed) there is the fact that the basin depth decrease leads to the increase of the height of the flexural-gravity wave.

关键词： Ice cover submarine flexural gravity wave source-sink system