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Deep bed filtration model for cake filtration and erosion

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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

Enhancement of coercivity,permeability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites for memory and high frequency devices

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Journal of rare Earths 2024年第6期42卷 1128-1135,I0005页

作者： i.Sardar M.D.Hossain M.S.Sikder M.N.i.Khan M.r.rahman Physics Discipline Khulna UniversityKhulna9208Bangladesh Department of Physics Khulna University of Engineering&TechnologyKhulna9203Bangladesh Department ofComputer Science and Engineering Northern University of Business&Technology KhulnaKhulna9100Bangladesh Material Science Division Atomic Energy CentreDhaka1000Bangladesh

Spinel cubic ferrites have huge applications in me mory and high frequency *** the improvement of these modern devices,the magnetic coercivity,permeability,and dielectric properties of a ferrite are the important *** article focuses on improving the magnetic coercivity,magnetic permeability,and dielectric properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ferrites,where x=0.00,0.06,and *** X-ray diffraction(XrD),Fourier transform infrared spectroscopy(FTir),field emission scanning electron microscopy(FESEM),energy dispersive X-ray(EDX),vibrating sample magnetometer(VSM),and an impedance analyzer were used to characterize the structural,magnetic,and dielectric properties of the *** XrD patterns indicate the formation of spinel cubic structure of the samples with a secondary peak(EuFeO_(3))for Eu doped *** densities and porosities of the samples follow an inverse trend,where the doped samples’lattice parameters are increased with the increment of rare earth Eu *** FTir analysis also proves the spinel cubic phase of the *** average grain size of the ferrites is obtained via FESEM images,and it is increased from 121 to 198 *** analysis confirms that doping of the Eu content also changes other hysteresis loop properties of Co_(0.2)Zn_(0.3)Ni_(0.5)Eu_(x)Fe_(2-x)O_(4) ***,the coercivity of the Eu doped samples is greater than that of the mother alloy(x=0.00).The EDX study shows that there is no impurity contamination in the *** permeability and dielectric measurements show an improved quality factor of the Eu-doped samples with low magnetic and dielectric *** dependent resistivity and impedance analysis also show the improved *** the observed properties of the samples,all the investigated ferrites might be strong candidates for potential applications in memory devices,magnetic sensors,and high frequency applications.

关键词： Ferrites raree arths Coercivity Permeability EDX resistivity

SANC Monte Carlo programs for small-angle Bhabha scattering

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Chinese Physics C 2024年第4期48卷 14-19页

作者： A.B.Arbuzov S.G.Bondarenko i.r.Boyko L.V.Kalinovskaya A.A.Kampf r.r.Sadykov V.L.Yermolchyk Bogoliubov Laboratory of Theoretical Physics JINRDubna141980 Russia Dzhelepov Laboratory of Nuclear Problems JINRDubna141980 Russia Dubna State University Dubna141982 Russia

Luminosity monitoring at e^(+)e^(−)colliders was investigated using SANC Monte Carlo event generator reneSANCe and integrator MCSANC for simulation of Bhabha scattering at low *** are presented for center-of-mass energies of the Z boson resonance and at 240 GeV for the conditions of typical luminosity *** is shown that bremsstrahlung events with extremely low electron scattering angles are relevant to match the precision tags of future electron-positron colliders.

关键词： luminosity Bhabha scattering QED Monte Carlo simulation

Fatigue and Corrosion Fatigue Properties of Mg-Zn-Zr-Nd Alloys in Glucose-Containing Simulated Body Fluids

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Acta Metallurgica Sinica(English Letters) 2024年第9期37卷 1533-1550页

作者： Xue Han Dan Zhang Song Zhang Mohammed r.i.Abueida Lili Tan Xiaopeng Lu Qiang Wang Huanye Liu School of Materials Science and Engineering Shenyang University of TechnologyShenyang110870China School and Hospital of Stomatology China Medical UniversityShenyang110001China Shi-Changxu innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China Shenyang National Laboratory for Materials Science Northeastern UniversityShenyang110819China

Medical bone implant magnesium(Mg)alloys are subjected to both corrosive environments and complex loads in the human *** increasing number of hyperglycemic and diabetic patients in recent years has brought new challenges to the fatigue performance of Mg ***,it is significant to study the corrosion fatigue(CF)behavior of medical Mg alloys in glucose-containing simulated body fluids for their clinical ***,the corrosion and fatigue properties of extruded Mg-Zn-Zr-Nd alloy in Hank’s balanced salt solution(HBSS)containing different concentrations(1 g/L and 3 g/L)of glucose were *** average grain size of the alloy is about 5μm,which provides excellent overall mechanical *** conditional fatigue strength of the alloy was 127 MPa in air and 88 MPa and 70 MPa in HBSS containing 1 g/L glucose and 3 g/L glucose,*** crack initiation points for alloys in air are oxide inclusions and in solution are corrosion *** corrosion rate of the alloy is high at the beginning,and decreases as the surface corrosion product layer thickens with the increase of immersion *** corrosion products of the alloy are mainly Mg(OH)_(2),MgO and a small amount of Ca-P *** electrochemical results indicated that the corrosion rate of the alloys gradually decreased with increasing immersion time,but the corrosion tendency of the alloy was greater in HBSS containing 3 g/L *** the one hand,glucose accelerates the corrosion process by adsorbing large amounts of aggressive Cl^(-)*** the other hand,glucose will be oxidized to form gluconic acid,and then reacts with Mg(OH)_(2) and MgO to form Mg gluconate,which destroys the corrosion product film and leads to the aggravation of corrosion and the accumulation of fatigue damage.

关键词： Mg alloys Corrosion fatigue Glucose Gluconic acid Corrosion product

The effect of electrical current on lubricant film thickness in boundary and mixed lubrication contacts measured with ultrasound

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Friction 2024年第8期12卷 1882-1896页

作者： Julio A.CAO-rOMErO-GALLEGOS Saeid TAGHiZADEH Oscar A.AGUiLAr-rOSAS r.S.DWYEr-JOYCE Leonardo i.FArFAN-CABrErA Tecnologico de Monterrey Escuela de Ingeniería y CienciasAve.Eugenio Garza Sada 2501MonterreyN.L.64849México Department of Mechanical Engineering Leonardo Centre for TribologyUniversity of SheffieldSheffield S13JDUK

This work explores experimentally the effects of DC electrical currents on lubricant film thickness alteration in lubricated sliding steel contacts in the boundary and mixed regime as measured by *** experiments were performed in a two-electrode cell-based pin-on-disk tester instrumented with ultrasonic *** and electrified tribological tests were conducted on steel flat-on-flat contacts under various speeds and loads using both a mineral base oil and a gear *** thickness,coefficient of friction(CoF),and electrical contact resistance(ECr)were measured during short experiments(30 s)in unelectrified and electrified(1.5 and 3 A)*** results suggest that film thickness,CoF,and all ECr are altered by passing DC currents through the *** particular,film thickness increased and decreased,respectively,by applying electricity at the different speeds and loads *** alterations were majorly ascribed to oil viscosity decrease by local heat and surface oxidation caused by electrical discharge and break down at the interface.

关键词： electrified sliding ultrasonic measurement electric vehicles pin-on-disk

Photosynthetic response to a winter heatwave in leading and trailing edge populations of the intertidal red alga Corallina offi-cinalis(rhodophyta)

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Acta Oceanologica Sinica 2024年第7期43卷 70-77页

作者： regina Kolzenburg Federica ragazzola Laura Tamburello Katy r.Nicastro Christopher D.McQuaid Gerardo i.Zardi UmeåMarine Sciences Centre UmeåUniversity90571 NorrbynSweden University of Portsmouth Institute of Marine SciencePortsmouth PO49LYUK Stazione Zoologica Anton Dohrn Genova Marine CenterGenova 16126Italy Stazione Zoologica Anton Dohrn Sicily Marine CenterPalermo 90149Italy Department of Zoology and Entomology Rhodes UniversityMakhanda(Grahamstown)6139South Africa Centre of Marine Sciences University of AlgarveFaro 8005-139Portugal Laboratoire d’Océanologie et de Géosciences Universitéde LilleLille 59000France Universitéde Caen Normandie Laboratoire de Biologie des Organismes et des Ecosystèmes AquatiquesCaen 14032France

Marine heatwaves(MHWs)caused by anthropogenic climate change are becoming a key driver of change at the ecosystem *** conditions experienced by marine organisms across their distribution,particularly towards the equator,are likely to approach their physiological limits,resulting in extensive mortality and subsequent changes at the population *** at the margins of their species’distribution are thought to be more sensitive to climate-induced environmental pressures than central populations,but our understanding of variability in fitness-related physiological traits in trailing versus leading-edge populations is *** a laboratory simulation study,we tested whether two leading(iceland)and two trailing(Spain)peripheral populations of the intertidal macroalga Corallina officinalis display different levels of maximum potential quantum efficiency(Fv/Fm)resilience to current and future winter MHWs *** study revealed that ongoing and future local winter MHWs will not negatively affect leading-edge populations of ***,which exhibited stable photosynthetic efficiency throughout the *** edge populations showed a positive though non-significant trend in photosynthetic efficiency throughout winter MHWs *** and equatorward populations did not produce significantly different results,with winter MHWs having no negative affect on Fv/Fm of either ***,we found no long-term regional or population-level influence of a winter MHWs on this species’photosynthetic ***,we found no statistically significant difference in thermal stress responses between leading and trailing ***,*** showed a trend towards higher stress responses in southern than northern *** responses rest on a variety of local population traits,they are difficult to predict based solely on thermal pressures.

关键词： marginal population coralline algae climate change ecophysiology photophysiology macroalgae Fv/Fm

Antibacterial HA-coatings on bioresorbable Mg alloy

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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

BaTiO3 solid solutions co-doped with Gd3+ and Eu3+:Synthesis,structural evolution and dielectric properties

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Journal of rare Earths 2024年第10期42卷 1920-1926页

作者： r.Martínez-López M.Pérez-Labra J.A.romero-Serrano F.r.Barrientos-Hernández M.reyes-Pérez M.i.Valenzuela-Carrillo G.Urbano-reyes V.E.reyes-Cruz G.i.Dávila-Pulido Academic Area of Earth Sciences and Materials Autonomous University of Hidalgo State Metallurgy and Materials Department ESIQIE-IPNUPALM Autonomous University of Coahuila Boulevard Adolfo López Mateos S/n

in this paper,the synthesis,structural evolution,and dielectric properties of BaTiO3solid solutions codoped with rare earth elements(Gd3+and Eu3+) prepared using the solid-state reaction method are *** pure precursor powders of BaCl3,TiO2,Gd2O3,and Eu2O3were mixed in stoichiometric proportions,ground in an agate mortar before being uniaxially pressed at 250 MPa and sintered at 1300℃ in air atmosphere for 6 h to obtain Ba1-3xGd2xTi1-3xEu4xO3（x=0,0.0015,0.01 and0.1）.X-ray diffraction（XrD） and rietveld's refinement results reveal the crystal phase ferroelectric tetragonal BaTiO3for the samples with x=0,0.0015 and 0.01, as well as a consistent increment in the lattice parameters caused by the *** solubility limit of Gd3+and Eu3+in the BaTiO3structure is reached for the sample with x>0.01,and the orthorhombic Eu2TiO5and monoclinic BaTi2O5secondary phases were *** raman results show the characteristic peaks of ferroelectric tetragonal BaTiO3around 716 cm-1（LO of A1 symmetry）,515 cm-1（TO of A1 symmetry）,and 305 cm-1（B1）.The maximum relative permittivity measured at 1 kHz was recorded to be 6151.8 for the sample with x=0.0015,and a decrease in the Curie temperature to 105℃ with respect to the undoped sample was *** punctual microanalysis for the samples with x=0.0015,0.01,and 0.1 reveals grains composed of Ba,Ti,O,Gd,and Eu homogeneously distributed in the *** Ba/Ti ratios for samples with x=0.0015,0.01 and 0.1 are 2.86,2.91,and 0.68,respectively,indicating substitution at the Ti site for samples with x=0.0015 and 0.01 and a substitution at the Ba site for the sample with x=0.1.

关键词： BaTiO3 Doping Europium Gadolinium rare earths Synthesis

The current status and future development of high-temperature conventional superconductivity

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National Science review 2024年第7期11卷 18-20页

作者： Mikhail i.Eremets High Pressure Chemistry and Physics Group Max-Planck-Institut für Chemie

This survey highlights key advancements in high-temperature superconductivity in hydrogen-rich materials, emphasizing the robust evidence and reproducibility of superconductivity under challenging experimental conditions of megabar pressures. in the near future, achieving room-temperature superconductivity is highly probable, and the field is expected to transition towards near-ambient-pressure superconductivity.

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