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Discovery of new MAX-phase-like layered ternary carbide V_(8)p_(6)C:Crystal structure,thermal expansion,and elastic properties

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Journal of Materials Science & Technology 2024年第7期174卷 55-62页

作者： H.X.Chen l.Sheng Z.l.Zhang X.C.Wen D.l.Yang X.Y.Ye p.Q.Dai School of Materials Science and Engineering Fujian University of TechnologyFuzhou 350118China Beijing Synchrotron radiation Facility Institute of High Energy PhysicsChinese Academy of ScienceBeijing 100049China Fujian provincial Key laboratory of Advanced Materials processing and Application Fuzhou 350118China State Key laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China

Due to the laminated structure,MAX phases and MAX-phase-like compounds possess outstanding dam-age tolerance capability with good thermal/electrical conductivity and other charming functional prop-erties,showing a bright future for structural-functional ***,a new MAX-phase-like ternary car-bide V_(8)p_(6)C with layered characteristics was *** to the alternate stacking of hexagonal-arranged M/A/X atom layers in MAX phases,V_(8)p_(6)C has a layered structure formed by a repeated stacking of the slabs consisting of V_(6)C-octahedrons and Vp 6-distorted-octahedrons in three-atomic layers *** thermal expansion anisotropy was revealed,with the thermal expansion coefficients(TECs)along a-axis,c-axis,and the average value,equal toα_(a)=8.55(5)μK^(−1),α_(c)=10.23(5)μK^(−1),andα_(l)=9.14(5)μK^(−1),*** dilation along the c-axis was mainly dominated by out-plane V-p bonds be-tween layered *** to the pressure-dependent lattice parameters,the polycrystalline bulk modulus(B_(0)=185(9)Gpa)and high compressibility anisotropy factor(B_(a)/B_(c)=1.64)was ***-while,the second-order elastic constants were calculated,and the elastic moduli,E=303 Gpa,B=198 Gpa,G=122 Gpa,andν=0.246,were *** the weak connection between layer slabs by out-plane V1-p bond was revealed by the bond stiffness model,with a bond stiffness close to the M-A bond in MAX ***,good damage tolerance capability was predicted according to paugh’s ratio(G/B=0.616)and Cauchy pressure(p_(a)=0 Gpa,p_(c)=-7.5 Gpa),even better than those of typical MAX *** discovery of V_(8)p_(6)C provides a new member of MAX-phase-like damage-tolerant ceramic with relatively low density,moderate thermal expansion,and anisotropic compressibility,and the unique lay-ered structure is inspiring for exploring new layered ternary ceramics.

关键词： New ternary carbide MAX phase Thermal expansion Elastic constants Anisotropy

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Convergent plate boundary environments for formation of≥3800 Ma mafic-ultramafic assemblages(Isua area,Greenland):Implications for early global geodynamics

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Geoscience Frontiers 2024年第3期15卷 119-136页

作者： Allen p.Nutman Clark r.l.Friend Vickie C.Bennett School of Earth Atmospheric and Life SciencesUniversity of WollongongWollongongNSW 2522Australia Glendale TiddingtonOxon OX92LQUK research School of Earth Sciences Australian National UniversityCanberraACT 2601Australia

In the gneiss terrane on the south side of the Eoarchean Isua supracrustal belt,ultramafic rocks with relict abyssal peridotite mineralogy(Bennett et al.,2002;Friend et al.,2002;Nutman et al.,2007;rollinson,2007;van de löcht et al.,2020),layered gabbros with cumulate ultramafic rocks,basalts and associated siliceous sedimentary rocks were tectonically-imbricated,prior to and during intrusion of ca.3800 Ma *** with3800 Ma basalts in the Outer Arc Group of the nearby Isua supracrustal belt,the composition of all these mafic rocks(e.g.,Th-Hf-Nb systematics,high Th/Yb,Ba/Nb,Ba/Yb ratios and negative Nb and Ti anomalies)shows affinity with modern suprasubduction rocks whose genesis involved fluid fluxing of the upper ***,the majority of these samples have Ba/Nb and Ba/Yb values less than in modern island arc magmas,but similar to many backarc basin magmas(e.g.,pearce and Stern,2006).It is unknown whether these ca.3800 Ma mafic rocks are,(i)arc rocks where the Ba/Nb and Ba/Yb signatures reflect lower surficial Ba in Eoarchean oceanic settings,or(ii)in direct comparison with phanerozoic suites,these signatures reflect a back-arc setting with interplay between fluid fluxing and decompressional *** tectonic intercalation of upper mantle with lower and upper crustal rocks,combined with the fluid-fluxing influences seen in chemistry of all the mafic rocks is best accommodated in a compressional Eoarchean convergent plate boundary setting within a mobile-lid *** stagnant lid scenarios of crust formation,if operative,must have co-existed or alternated with mobile-lid regimes by 3800 Ma.

关键词： Eoarchean Fluid-fluxing plate tectonics Suprasubduction Crustal evolution

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On the functions of astrocyte-mediated neuronal slow inward currents

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Neural regeneration research 2024年第12期19卷 2602-2612页

作者： Balázs pál Department of physiology Faculty of MedicineUniversity of DebrecenDebrecenHungary

Slow inward currents are known as neuronal excitatory currents mediated by glutamate release and activation of neuronal extra synaptic N-met hyl-D-aspartate receptors with the contribution of *** events are significantly slower than the excitatory postsynaptic *** of slow inward currents are determined by seve ral factors including the mechanisms of astrocytic activation and glutamate release,as well as the diffusion pathways from the release site towards the extra synaptic recepto *** are stimulated by neuronal network activity,which in turn excite neurons,forming an astrocyte-neuron feedback *** as a consequence of brain edema,astrocytic swelling can also induce slow inward currents under pathological *** is a growing body of evidence on the roles of slow inward currents on a single neuron or local network *** events often occur in synchro ny on neurons located in the same astrocytic *** synchronization of neuronal excitability,slow inward currents also set synaptic strength via eliciting timing-dependent synaptic *** addition,slow inward currents are also subject to non-synaptic plasticity triggered by long-la sting stimulation of the excitatory *** note,there might be important regionspecific differences in the roles and actions triggering slow inward *** greater networks,the pathophysiological roles of slow inward currents can be better understood than physiological *** inward currents are identified in the pathophysiological background of autism,as slow inward currents drive early hypersynchrony of the neural *** inward currents are significant contributors to paroxysmal depolarizational shifts/interictal *** events are related to epilepsy,but also found in Alzheimer's disease,parkinson's disease,and stroke,leading to the decline of cognitive *** with features overlapping with slow inward currents(excitatory,N-methyl-Dasp

关键词： astrocyte cortical spreading depolarization gliotransmission glutamate neural synchronization NMDA receptor paroxysmal depolarizational shift slow inward current

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HVOF-sprayed HAp/S53p4 BG composite coatings on an AZ31 alloy for potential applications in temporary implants

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Journal of Magnesium and Alloys 2024年第1期12卷 345-360页

作者： Carlos A.poblano-Salas John Henao Astrid l.Giraldo-Betancur paola Forero-Sossa Diego German Espinosa-Arbelaez Jorge A.González-Sánchez luis r.Dzib-pérez Susana T.Estrada-Moo Idelfonso E.pech-pech CIATEQ A.C. Av.Manantiales 23-AParque Industrial Bernardo QuintanaEl MarquésQuerétaro 76246Mexico CONAHCYT-CIATEQ A.C. Av.Manantiales 23-AParque Industrial Bernardo QuintanaEl MarquésQuerétaro 76246Mexico CONAHCYT-Cinvestav Libramiento Norponiente#2000.Fraccionamiento Real de JuriquillaQuerétaro 76230Mexico Universidad Tecnológica de Querétaro Av.Pie de la Cuesta N°2501Querétaro 76148Mexico CIDESI Av.Playa Pie de la Cuesta No 702Col.San PabloQuerétaro 76125Mexico Center for Corrosion research Autonomous University of CampecheAv.Héroe de Nacozari No.480P.C.24070San Francisco de CampecheCam.Mexico

Bioactive thermal spray coatings produced via high-velocity oxygen fuel spray(HVOF)from hydroxyapatite(HAp)and bioactive glasses(BG)have the potential to be employed on temporary implants due to the ability of both HAp and BG to dissolve and promote osseointegration,considering that both phases have different reaction and dissolution rates under in-vitro *** the present work,75%***-25%wt.S53p4 bioactive glass powders were HVOF-sprayed to obtain HAp/S53p4 BG composite coatings on a bioresorbable AZ31 *** study is focused on exploring the effect of the stand-off distance and fuel/oxygen ratio variation as HVOF parameters to obtain stable structural coatings and to establish their effect on the phases and microstructure produced in those *** characterization techniques,such as scanning electron microscopy,X-ray diffraction,and Fourier transform infrared spectroscopy,were employed to characterize relevant structural and microstructural properties of the composite *** results showed that thermal gradients during coating deposition must be managed to avoid delamination due to the high temperature achieved(max 550℃)and the differences in coefficients of thermal *** was also found that both spraying distance and oxygen/fuel ratio allowed to keep the hydroxyapatite as the main phase in the *** addition,in-vitro electrochemical studies were performed on the obtained HAp/S53p4 BG composite coatings and compared against the uncoated AZ31 *** results showed a significant decrease in hydrogen evolution(at least 98%)when the bioactive coating was applied on the Mg alloy during evaluation in simulated body fluid(SBF).

关键词： Coatings Composites Thermal spray Temporary implants Hydrogen evolution

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Chronic active and atrophic gastritis as significant contributing factor to the development of gastric cystica profunda

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World Journal of Gastroenterology 2024年第17期30卷 2308-2310页

作者： Veronika papp pál Miheller Department of Surgery Transplantation and GastroenterologySemmelweis UniversityBudapest 1082Hungary

Gastric cystica profunda(GCp)is an uncommon but underestimated gastric *** precancerous potential determines its *** addition to previous mucosa injury due to operations,biopsy or polypectomy,chronic active and atrophic gastritis may also lead to the development of *** carefully examining the stomach and taking biopsy samples from the susceptible regions,the stage of atrophy can be *** atrophic gastritis is a risk factor for cancer evolvement and it can also contribute to GCps *** frequently occur close to early gastric cancers(EGCs)or EGC can arise from the cystic *** resection is an effective and minimally invasive treat-ment in GCp.

关键词： Gastric cystica profunda Chronic active gastritis Atrophic gastritis Operative link for Gastritis Assessment staging Early gastric cancer Endoscopic resection

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resistance of full-scale beams against close-in *** modeling and field tests

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Defence Technology（防务技术） 2024年第10期40卷 35-47页

作者： A.prado A.Alañón r.Castedo A.p.Santos l.M.lópez M.Chiquito M.Bermejo C.Oggeri Escuela politécnica Superior dé Avila Universidad de SalamancaÁvila05003Spain E.T.S.I.Minas y Energía Universidad Politecnica de MadridMadrid28003Spain Department of Engineering Aviation and TechnologySaint Louis UniversityMadrid28003Spain Department of Environment Land and Infrastructure Engineering(DIATI)Politecnico di TorinoTorino10129Italy

This paper explores the performances of a finite element simulation including four concrete models applied to a full-scale reinforced concrete beam subjected to blast loading. Field test data has been used to compare model results for each case. The numerical modelling has been, carried out using the suitable code lS-DYNA. This code integrates blast load routine(CONWEp) for the explosive description and four different material models for the concrete including: Karagozian & Case Concrete, Winfrith, Continuous Surface Cap Model and riedel-Hiermaier-Thoma models, with concrete meshing based on 10, 15, and 20 mm. Six full-scale beams were tested: four of them used for the initial calibration of the numerical model and two more tests at lower scaled distances. For calibration, field data obtained employing pressure and accelerometers transducers were compared with the results derived from the numerical simulation. Damage surfaces and the shape of rupture in the beams have been used as references for comparison. Influence of the meshing on accelerations has been put in evidence and for some models the shape and size of the damage in the beams produced maximum differences around 15%. In all cases, the variations between material and mesh models are shown and discussed.

关键词： Blast test Numerical simulation lS-DYNA Concrete model Mesh effect Full-scale beams

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Solid-liquid extraction for yttrium recovery using porous polymeric resin(XAD-7) functionalized with D_(2)EHpA

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Journal of rare Earths 2024年第9期42卷 1764-1773,I0005页

作者： p.A.Martínez-Montoya r.G.Sanchez-Alvarado D.Y.Medina-Velazquez M.l.Carrera-Jota p.Garnica-Chávez A.de J.Morales-ramirez Higher School of Chemical Engineering and Extractive Industries ESIQIEIPNDepartment of Metallurgical EngineeringUPALM S/NCol.LindavistaGustavo A.Madero Cd.de MéxicoC.P07738Mexico Metropolitan Autonomous University Department of MaterialsBasic Sciences and EngineeringAv.San Pablo No.180Col.Reynosa TamaulipasCd.de MéxicoC.P02200Mexico Center for research and Technological Innovation CIITECIPNCda.de CECATIs/nSanta CatarinaAzcapotzalcoC.P02250CDMXMexico

The recovery of yttrium is proposed by applying a solid-liquid extraction process using di-2-ethyl hexylphosphoric acid(D2EHpA) as extracting *** extracting agents were supported on a macro porous polymeric resin XAD-7(solid phase).Yttrium ions extraction and discharge tests were performed,firstly from a synthetic aqueous solution of 100 mg/l Y(liquid phase) at 25℃ with *** effects of pH of aqueous solutions bearing yttrium,volume fraction of extracting agents and the solid/liquid(S/l)ratio on the yttrium recovery were *** most favorable conditions for yttrium ions extraction are;20 vol% D_(2)EHpA functionalized resin,pH=1.5 and an S/l ratio of 10 mg/ml The discharge of yttrium ions was done under the same conditions of extraction stage,using a 2 mol/l [H_(2)SO_(4)] as stripping *** to 80% yttrium is extracted,while 75% yttrium is recovered in the striping *** all experiments,the reaction equilibrium is reached after 20 min,and the kinetics for the extraction stage was determined as a second-order ***,experiments were carried out to discharge the yttriumloaded resins,and it has been determined that the best pH value to strip the Y ions is *** tests of extraction and discharge for yttrium ions show that the functionalized resin can work at least five cycles without decreasing its ***,the proposed process was tested in a real solution with Y ions fro m a waste fluorescent la mp powder leached in H_(2)SO_(4),demonstrating the ability to effectively recover yttrium,separating it from various metals from the studied residue.

关键词： Yttrium recovery rare earth solid-liquid extraction XAD-7 resin Fluorescent lamps recycling Solid-liquid kinetics extraction

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Effect of radiative loss mechanisms on FIr thermometric parameters of Nd^(3+)-doped lithium tellurite glasses

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Journal of rare Earths 2024年第7期42卷 1250-1257,I0002页

作者： C.Y.Morassuti A.p.l Silva l.A.O.Nunes S.M.lima l.H.C.Andrade Optical and photothermal Spectroscopy Group(GEOF) Center for Studies in Natural Resources(CERNA)State University of Mato Grosso do Sul(UEMS)C.P.351DouradosMSBrazil renato Archer Information Technology Center Dom Pedro I Highway(SP-65)Km 1436-Chácaras Campos dos AmaraisCampinasSPBrazil Institute of physics of São Carlos University of São PauloSão CarlosSPBrazil

Nd^(3+)-doped tellurite glasses are promising materials for thermometers based on the fluorescence intensity ratio(FIr)***,at high Nd^(3+)concentrations,energy transfer(ET)processes such as optical reabsorption and cross-relaxation can affect the Nd^(3+)emission,which has been little explored in the ***,the present work investigated the use of Nd^(3+)-doped tellurite glass(samples doped with Nd^(3+)at 0.2 mol%,0.5 mol%,2.0 mol%,and 4.0 mol%)in fluorescence thermometers,in the temperature range from 299 to 371 *** results indicate a strong dependence of the FIr parameters on the Nd^(3+)concentration,due to changes in the emission band profiles caused by optical reabsorption of the Nd^(3+)emissions and cross-relaxation processes.A decrease of the relative sensitivity of the ratio^(4)F_(5/2)→^(4)I_(9/2)/^(4)F_(3/2)→^(4)I_(9/2)is observed for samples doped with higher amounts of Nd^(3+).The maximum relative sensitivity at 299 K is 3.00%/K,which is the highest value among the reported Nd^(3+)ions.

关键词： Nd^(3+)-doped tellurite glass Fluorescence intensity ratio Optical thermometry Judd-Ofelt rare earths

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Severe acute respiratory syndrome-coronavirus-2(SArS-COV-2)infection of pneumocytes with vaccination and drug therapy:Mathematical analysis and optimal control

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International Journal of Biomathematics 2024年第2期17卷 299-334页

作者： r.Viriyapong p.Inkhao Department of Mathematics Faculty of Science Naresuan University Phitsanulok65000Thailand

We propose a mathematical model studying a within-host infection dynamics of SArSCoV-2 in *** model incorporates immune response,vaccination and antiviral *** crucial properties of the model-the existence,positivity and boundary of solutions are *** points and the basic reproduction number are *** stability of each equilibrium point is *** control is applied to the model by adding three control variables:vaccination,treatment by Favipiravir and treatment by *** results show that each individual control could reduce SArS-CoV-2 infection in some aspects;however,with a combination of three controls,we obtain the best results in reducing SArS-CoV-2 *** study has emphasized the importance of prevention by vaccine and the antiviral treatments.

关键词： SArS-CoV-2 vaccination drug therapy immune response optimal control

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System integration analysis of a zeolite 13x thermal energy storage

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Energy and Built Environment 2024年第4期5卷 568-579页

作者： S.De Antonellis l.p.M.Colombo p.Castellazzi A.rossetti l.Marocco politecnico di Milano Department of Energyvia Lambruschini 4Milan 20156Italy ricerca sul Sistema Energetico-rSE S.p.A. Tecnologie di Generazione e Materialivia R.Rubattino 54Milan 20134Italy

Nowadays a major energy transition aimed at cutting CO 2 emissions has begun,with the ambitious goal of drasti-cally reducing the dependence on fossil fuels and promoting the use of renewable energy *** this context,energy storage systems play a key role in ensuring a stable,secure and time-aligned energy *** sorption thermal energy storages(TESs)can contribute to such transition,since they are simple and cheap devices able to provide a hot airflow with a high energy density and to store energy for long *** this work,open sorption TES systems operated with Zeolite13X are investigated with a focus on the integration in practical ***,the experimental analysis and modelling of the sole TES system is ***,the integration of the TES at system level is carried *** analysis evidences that a significant reduction of storage capac-ity occurs if air humidification is necessary before the adsorption process or afterwards to keep adequate indoor comfort conditions for the *** the exemplary case study considered,an energy density of 150 kWhm^(−3) can drop to 40 kWhm−3 in case of complete compensation of the adsorbed water through a *** paper provides useful guidelines for evaluating the performance of a TES integrated system in terms of specific energy and *** also identifies applications involving high latent loads(e.g.,swimming pools,locker rooms)or for which low relative air humidity is required(*** of vehicles to prevent condensation on windows)as particularly beneficial for using a TES system.

关键词： Energy storage Adsorption Zeolite System integration Numerical model

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