检索结果-南通市图书馆

Effect of Ta_(2)O_(5)nanoparticles on bioactivity,composition,structure,in vitro and in vivo behavior of PEO coatings on Mg-alloy

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6期12卷 2360-2379页

作者： D.v.Mashtalyar i.M.imshinetskiy v.v.Kashepa K.v.Nadaraia M.A.Piatkova A.i.Pleshkova K.A.Fomenko A.Yu.Ustinov S.L.Sinebryukhov S.v.Gnedenkov institute of Chemistry Far Eastern BranchRussian Academy of SciencesVladivostok690022Russia Far Eastern Federal University Vladivostok690950Russia Regional Clinical Dermatovenerological Dispensary Vladivostok690033Russia

The present study investigates the physical and chemical characteristics,behavior in vitro and in vivo,and biocompatibility of coatings containing Ta_(2)O_(5),which are obtained by plasma electrolytic oxidation(PEO)on MA8 magnesium *** obtained coatings demonstrate in vivo biocompatibility and in vitro *** to the base PEO coating,the layers containing Ta_(2)O_(5)facilitate the development of apatite in simulated body fluid,suggesting that the inclusion of nanoparticles improves bioactivity of the *** was found that incorporation of Ta_(2)O_(5)nanoparticles increases roughness and porosity of the formed layers by increasing particle concentration in electrolytes for the PEO process contributing to sufficient soft tissue ingrowth in *** on in vivo studies,these coatings also provide favorable tissue response and minimal inflammatory reaction in comparison with the bare magnesium alloy due to protection of living tissues from deleterious corrosion events of magnesium implant such as local alkalization and intense hydrogen *** results obtained in the present study concluded biocompatibility,tissue integration of the PEO coatings containing Ta_(2)O_(5)nanoparticles making them a promising protective layer for biodegradable magnesium implants.

关键词： Plasma electrolytic oxidation Bioactive coatings Tantalum pentoxide Simulated body fluid(SBF) Apatite formation Histology

Deep bed filtration model for cake filtration and erosion

在线全文

学校读者我要写书评

暂无评论

Applied Mathematics and Mechanics(English Edition) 2024年第2期45卷 355-372页

作者： L.i.KUZMiNA Y.v.OSiPOv A.R.PESTEREv Department of Applied Mathematics HSE UniversityMoscow 101000Russia Department of Computer Science and Applied Mathematics Moscow State University of Civil EngineeringMoscow 129337Russia

Many phenomena in nature and technology are associated with the filtration of suspensions and colloids in porous media. Two main types of particle deposition,namely, cake filtration at the inlet and deep bed filtration throughout the entire porous medium, are studied by different models. A unified approach for the transport and deposition of particles based on the deep bed filtration model is proposed. A variable suspension flow rate, proportional to the number of free pores at the inlet of the porous medium, is considered. To model cake filtration, this flow rate is introduced into the mass balance equation of deep bed filtration. For the cake filtration without deposit erosion,the suspension flow rate decreases to zero, and the suspension does not penetrate deep into the porous medium. in the case of the cake filtration with erosion, the suspension flow rate is nonzero, and the deposit is distributed throughout the entire porous medium. An exact solution is obtained for a constant filtration function. The method of characteristics is used to construct the asymptotics of the concentration front of suspended and retained particles for a filtration function in a general form. Explicit formulae are obtained for a linear filtration function. The properties of these solutions are studied in detail.

关键词： deep bed filtration cake filtration porous medium particle deposition and erosion analytical solution concentration front

Antibacterial HA-coatings on bioresorbable Mg alloy

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5期12卷 1965-1985页

作者： K.v.Nadaraia D.v.Mashtalyar M.A.Piatkova A.i.Pleshkova i.M.imshinetskiy M.S.Gerasimenko E.A.Belov v.v.Kumeiko D.N.Kozyrev K.A.Fomenko v.v.Mostovaya B.R.Torpanov A.R.Biktimirov i.S.Osmushko S.L.Sinebryukhov S.v.Gnedenkov institute of Chemistry FEB RAS 159 Pr.100-letiya VladivostokaVladivostok 690022Russia Far Eastern Federal University 10 Ajax BayRussky IslandVladivostok 690922Russia A.v.Zhirmunsky National Scientific Center of Marine Biology FEB RAS 17 St.PalchevskogoVladivostok 690041Russia Regional Clinical Dermatovenerological Dispensary 18 V St.GamarnikaVladivostok 690033Russia NMiC“Treatment and Rehabilitation Center” 3 Ivankovskoe highwayMoscow 125367Russia

in this study,a calcium-phosphate coating was formed on a Mg-Mn-Ce alloy by the plasma electrolytic oxidation(PEO).The antibiotic vancomycin,widely used in the treatment of infections caused by Staphylococcus aureus(***),was impregnated into the *** with vancomycin showed high bactericidal activity against *** mechanical and electrochemical properties of the formed coatings were studied,as well as in vitro cytotoxicity tests and in vivo tests on mature male rats were *** to SEM,EDS,XRD and XPS data,coatings had a developed morphology and contained hydroxyapatite,which indicates high *** analysis of roughness of coatings without and with vancomycin did not reveal any differences,confirming the high roughness of the *** electrochemical tests,an increase in corrosion resistance by more than two times after the application of PEO coatings was *** to the results of an in vivo study,after 28 days of the implantation of samples with calcium phosphate PEO coating and vancomycin,no signs of inflammation were observed,while an inflammatory reaction developed in the area of implantation of bare alloy,followed by *** release tests from the coatings show a sharp decrease in the concentration of the released antibiotic on day 7 and then a gradual decrease until day *** the experiment,no significant deviations in the condition and behavior of the animals were observed;clinical tests did not reveal a systemic toxic reaction.

关键词： Bioactive coatings Biocompatibility Mg alloy Plasma electrolytic oxidation Hydroxyapatite vancomycin

Microstructure， electrochemical， wear and corrosive wear performance of laser-based powder bed fusion(lpbf) and wrought biomedical Ti-6Al-4v alloys

在线全文

学校读者我要写书评

暂无评论

Transactions of Nonferrous Metals Society of China 2024年

作者： A.G.Lekatou B.v.Efremenko v.Haoui v.G.Efremenko S.Emmanouilidou v.i.Zurnadzhy i.Petryshynets Yu.G.Chabak i.i.Sili Laboratory of Applied Metallurgy Department of Materials Science and Engineering School of Engineering University of ioannina institute of Materials Science and Computing University Research Center of ioannina (URCi) Pryazovskyi State Technical University Department of Physics institute of Materials Research of Slovak Academy of Sciences

Wrought and laser powder bed fusion （LPBF） Ti-6Al-4v specimens were comparatively evaluated， with the objective to determine LPBF Ti-6-4’s suitability for biomedical applications. Testing included nanoindentation， cyclic polarization in simulated body fluid （SBF， 37 ℃ ）， and dry and SBF “Ball-on-Plate” sliding. Wrought Ti-6-4 exhibited a lamellar （α+β） microstructure， whereas LPBF displayed a fine-grained α'-martensite microstructure. LPBF Ti-6-4 demonstrated ～3% higher indentation modulus and ～32% higher hardness， while wrought Ti-6-4 showed ～8% higher plasticity. Both alloys exhibited low corrosion rates (10–5mA/cm2order) and true passivity (10–4mA/cm2order). No localized corrosion was observed in either alloy， except for occasional metastable pitting in the LPBF alloy. However， LPBF Ti-6-4 presented higher corrosion rate and passive current， ascribed to its martensitic structure. During dry sliding， LPBF Ti-6-4 exhibited ～14% lower volume loss compared to wrought Ti-6-4. Sliding in SBF increased volume losses for both alloys， with wear resistances nearly equalized， as the advantage of LPBF Ti-6-4 decreased due to more intensive wear-accelerated corrosion induced by the stressed martensite. Overall， the results demonstrate the suitability of LPBF Ti-6Al-4v for biomedical uses.

关键词：

Selection of shaped charges parameters for producing aluminum particles with velocities in the range of 2.5-16 km/s

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第8期38卷 126-135页

作者： vladimir i.Kolpakov Sergey v.Fedorov Ekaterina P.vinogradova irina A.Bolotina Bauman Moscow State Technical University Moscow 105005Russia

Testing rocket and space technology objects in ground conditions for resistance to the impact of meteoroids and fragments of space debris can be carried out using shaped charges. To substantiate the design parameters of shaped charges that ensure the formation of aluminum particles in a wide velocity range(from 2.5 to 16 km/s), numerical modeling of the formation process was carried out within the framework of a two-dimensional axisymmetric problem of continuum mechanics using three different computing codes to increase the reliability of the results. The calculations consider shaped charges with a diameter of 20-100 mm with aluminum liners of various shapes. it is shown that the formation of particles with velocities close to the lower limit of the considered range is ensured by gently sloping segmental liners of degressive thickness. To form higher-velocity particles with velocities over 5 km/s, it is proposed to use combined liners, the jet-forming part of which has the shape of a hemisphere of constant thickness or the shape of a semi-ellipsoid or semi-superellipsoid of rotation of degressive thickness.

关键词： Space debris Meteoric impact Explosion Shaped charge High-velocity aluminum element Segmental liner Combined liner Numerical simulation

Photoluminescence,structural and antibacterial properties of co-doped β-Ca3（PO4）2-type phosphates Ca8CuRE（PO4）7（RE=Eu-Er）

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 Rare Earths 2024年第9期42卷 1658-1668页

作者： ivan v.Nikiforov Ekaterina v.iliin Bogdan i.Lazoryak Sergey M.Aksenov Pavel v.Slukin Dina v.Deyneko Department of Chemistry Lomonosov Moscow State University Laboratory of Arctic Mineralogy and Material Sciences Kola Science CentreRussian Academy of Sciences Geological institute Kola Science CentreRussian Academy of Sciences State Scientific Center of Applied Microbiology and Biotechnology of Rospotrebnadzor 24

Novel Ca8CuRE（PO4）7where RE3+=Eu3+,Tb3+,Dy3+,Ho3+and Er3+were synthesized by a solid-state method in *** structures of the samples were characterized by powder X-ray diffraction using Rietveld refinement to determine the occupation of crystal *** samples are found to have a centrosymmetric structure with space group R3c,as shown by dielectric *** synthesized Ca8CuRE（PO4）7samples have multifunctional *** Cu2+ions provide antibacterial properties,while the rare earth elements ions exhibit luminescence properties,and the β-Ca3（PO4）2-type host is *** photoluminescence properties of RE3+ions were studied and compared with other simmilar Ca8MRE（PO4）7phosphates,where M is a divalent *** photoluminescence intensity quenching in terms of energy transfer from RE3+to Cu2+is *** bioactive properties were studied in relation to antibacterial activity against *** and *** syntesized Ca8CuRE（PO4）7samples demonstrate very high and stable inhibition of bacteria *** correlation between crystal structure and properties is *** combining multiple approaches to the directio nal design of such materials,several important properties within a single chemical compound to achieve biovisualization and bioactive properties simultaneously can be combined.

关键词： Whitlockite-type structure Bioactive phosphates TCP Photoluminescence Rare earths

Design of Biologically Active Macromolecular Ligands and Their Luminescent Complexes with Terbium ions

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Chinese Journal of Polymer Science 2024年第5期42卷 604-611,I0007页

作者： Tatiana N.Nekrasova Andrei i.Fischer Natalia A.Nesterova Anatoliy v.Dobrodumov Anzhelika v.Garshinina Olga D.Shuvaeva Natalya v.Zakharova Evgenii F.Panarin institute of Macromolecular Compounds Russian Academy of Sciences31 Bolshoy pr.St Petersburg199004Russia Smorodintsev Research institute of influenza Russian Ministry of Health15/17 ul.prof.PopovaSt Petersburg197376Russia

Water-soluble copolymers of p-methacrylamidobenzoic acid(MABA)with neutral comonomers(N-vinylpyrrolidone(vP),N-methyl-N-vinylacetamide(MvAA),N-methacryloyl glucosamine(MAG))and anionic comononer sodium styrene sulfonate(NaSS)were synthesized by radical *** interactions between the prepared copolymers and Tb^(3+)ions in aqueous solutions were studied;the significant influence of chemical structure of a comonomer on luminescence intensity of Tb^(3+)complexes with the copolymers was *** luminescence intensity of Tb^(3+)complexes with the copolymers containing N-vinylamide units(vP,MvAA)is three times more intense than that observed for the complexes between Tb^(3+)and MAG-containing *** the case of NaSS-containing copolymers,the luminescence intensity is controlled by the values of binding constants between Tb^(3+)and MABA and the content of MABA units in a *** studied copolymers and their complexes with Tb^(3+)have low cytotoxicity and a pronounced antiviral activity against human respiratory syncytial virus.

关键词： Luminescence Water-soluble copolymers Lanthanide complexes Antiviral activity Cytotoxicity

Polariton lasing in Mie-resonant perovskite nanocavity

在线全文

学校读者我要写书评

暂无评论

Opto-Electronic Advances 2024年第4期7卷 27-42页

作者： Mikhail A.Masharin Daria Khmelevskaia valeriy i.Kondratiev Daria i.Markina Anton D.Utyushev Dmitriy M.Dolgintsev Alexey D.Dmitriev vanik A.Shahnazaryan Anatoly P.Pushkarev Furkan isik ivan v.iorsh ivan A.Shelykh Hilmi v.Demir Anton K.Samusev Sergey v.Makarov UNAM-institute of Materials Science and Nanotechnology National Nanotechnology Research CenterDepartment of Electrical and Electronics EngineeringDepartment of PhysicsBilkent UniversityAnkara 06800Turkey iTMO University School of Physics and EngineeringSt.Petersburg 197101Russia Abrikosov Center for Theoretical Physics MIPTDolgoprudnyiMoscow Region 141701Russia LUMiNOUS!Center of Excellence for Semiconductor Lighting and Displays School of Electrical and Electronic EngineeringSchool of Physical and Mathematical SciencesSchool of Materials Science and EngineeringNanyang Technological UniversitySingapore 639798Singapore Department of Physics Engineering Physics and AstronomyQueen’s UniversityKingstonOntario K7L 3N6Canada Science institute University of IcelandDunhagi 3IS-107ReykjavikIceland Experimentelle Physik 2 Technische Universität DortmundDortmund 44227Germany Qingdao innovation and Development Center Harbin Engineering UniversityQingdao 266000China

Deeply subwavelength lasers(or nanolasers)are highly demanded for compact on-chip bioimaging and sensing at the *** of the main obstacles for the development of single-particle nanolasers with all three dimensions shorter than the emitting wavelength in the visible range is the high lasing thresholds and the resulting *** we ex-ploit exciton-polariton condensation and mirror-image Mie modes in a cuboid CsPbBr3 nanoparticle to achieve coherent emission at the visible wavelength of around 0.53μm from its ultra-small(≈0.007μm3 or≈λ3/20)semiconductor *** polaritonic nature of the emission from the nanocavity localized in all three dimensions is proven by direct com-parison with corresponding one-dimensional and two-dimensional waveguiding systems with similar material *** a deeply subwavelength nanolaser is enabled not only by the high values for exciton binding energy(≈35 mev),re-fractive index(>2.5 at low temperature),and luminescence quantum yield of CsPbBr3,but also by the optimization of po-laritons condensation on the Mie resonances with quality factors improved by the metallic ***,the key parameters for optimal lasing conditions are intermode free spectral range and phonons spectrum in CsPbBr3,which govern polaritons condensation *** chemically synthesized colloidal CsPbBr3 nanolasers can be potentially de-posited on arbitrary surfaces,which makes them a versatile tool for integration with various on-chip systems.

关键词： nanolaser perovskite polariton Mie resonance exciton-polariton

Measurement of yields and angular distributions ofγ-quanta from the interaction of 14.1 Mev neutrons with oxygen,phosphorus,and sulfur

在线全文

学校读者我要写书评

暂无评论

Chinese Physics C 2024年第3期48卷 79-92页

作者： D.N.Grozdanov N.A.Fedorov S.B.Dabylova Yu.N.Kopatch i.N.Ruskov v.R.Skoy T.Yu.Tretyakova C.Hramco P.i.Kharlamov G.v.Pampushik P.G.Filonchik A.v.Andreev Joint institute for Nuclear Research(JiNR) DubnaRussia institute for Nuclear Research and Nuclear Energy Bulgarian Academy of SciencesSofiaBulgaria Faculty of Physics Lomonosov Moscow State UniversityMoscowRussia L.N.Gumilyov Eurasian National University AstanaKazakhstan Skobeltsyn institute of Nuclear Physics Moscow State UniversityMoscowRussia institute of Chemistry of Moldova ChisinauRepublic of Moldova Moscow institute of Physics and Technology MoscowRussia

A study of the inelastic scattering of neutrons with an energy of 14.1 Mev on the nuclei of oxygen,phosphorus,and sulfur was performed at the TANGRA facility at JiNR(Dubna).The experiment aimed to refine existing data and obtain new data on the yields and angular distributions ofγ-quanta emitted by the studied nuclei due to neutron-induced nuclear reactions using the tagged neutron *** types of detector systems were used to registerγ-***γ-ray yields were measured using a high-purity germanium(HPGe)*** angular distributions ofγ-rays were obtained using a system of 18 scintillation detectors based on bismuth germanite Bi_(4)Ge_(3)O_(12)(BGO)located around the *** performed experiments measured the yields of two transitions for the reaction of tagged neutrons with 16O,nine transitions for the reaction with ^(31)P,and nine transitions for the reaction with ^(32)S for the first *** angular anisotropy of theγ-radiation accompanying the inelastic scattering of neutrons with an energy of 14.1 Mev on ^(31)P nuclei was also measured for the first time.

关键词： tagged neutron method yields of gamma-quanta high-resolution gamma-spectrometry neutron-nuclear reactions neutron scattering