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In-situ study of the m.crostructure evolution during tension of a m.-Y-Zn-Al alloy processed by rapidly solidified ribbon consolidation technique

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Journal of m.gnesium.and Alloys 2024年第5期12卷 2024-2040页

作者： Jeno Gubicza Kristián m.this p.ter Nagy p.ter Jenei Zoltán Hegedus Andrea Farkas Jozef Vesely Shin-ichi Inoue Daria Drozdenko Yoshihito Kawam.ra Departm.nt of m.terials physics Faculty of ScienceEotvos Loránd UniversityPázmány P.sétány 1/ABudapest H-1117Hungary Departm.nt of physics of m.terials Faculty of Mathematics and PhysicsCharles UniversityKe Karlovu 512116 Praha 2Czech Republic Deutsches Elektronen-Synchrotron DESY Notkestr.85Hamburg 22603Germany m.gnesium.Research Center Kumamoto University2-39-1 KurokamiChuo-kuKumamoto 860-8555Japan

m.-Y-Zn-Al alloys processed by rapidly solidified ribbon consolidation(RSRC)technique exhibit an exceptional m.chanical perform.nce indicating prom.sing application *** m.terial has a bim.dal m.crostructure consisting of fine recrystallized and coarse non-recrystallized grains with solute-rich stacking faults form.ng cluster arranged layers(CALs)and nanoplates(CANaps),or com.lete long period stacking ordered(LpSO)*** order to reveal the deform.tion m.chanism.,in-situ synchrotron X-ray diffraction line profile analysis was em.loyed for a detailed study of the dislocation arrangem.nt created during tension in m.-0.9%Zn-2.05%Y-0.15%Al(at%)*** uncovering the effect of the initial m.crostructure on the m.chanical perform.nce,additional sam.les were obtained by annealing of the as-consolidated specim.n at 300 and 400℃ for 2 *** heat treatm.nt at 300℃ had no significant effect on the initial m.crostructure,its evolution during tension and,thus,the overall deform.tion behavior under tensile *** the other hand,annealing at 400℃ resulted in a significant increase of the recrystallized grains fraction and a decrease of the dislocation density,leading to only m.nor degradation of the m.chanical *** m.xim.m.dislocation density at the failure of the sam.les corresponding to the plastic strain of 10-25% was estim.ted to be about 16-20×10^(14)m.(-2).The diffraction profile analysis indicated that m.st dislocations form.d during tension were of non-basal and pyram.dal types,what was also in agreem.nt with the Schm.d factor values revealed independently from.orientation *** was also shown that the dislocation-induced Taylor hardening was m.ch lower below the plastic strain of 3% than above this value,which was explained by a m.del of the interaction between prism.tic dislocations and CANaps/LpSO plates.

关键词： m.-Zn-Y-Al alloy Long period stacking ordered(LpSO)phase Cluster arranged nanoplates(CANaps) Annealing Tension Dislocation density Hardening

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Niche differentiation am.ng facultative filter feeders: Insights from.invasive ponto-Caspian m.sids

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Current Zoology 2024年第4期70卷 513-521页

作者： p.ter Borza Varsha Rani Csaba F.Vada Institute of Aquatic Ecology Centre for Ecological ResearchKarolina ut 29.1113 BudapestHungary Doctoral School of Biology Institute of BiologyEotvos Lorand UniversityPazmany Péter sétany 1/C1117 BudapestHungary

The degree of dietary specialization has a fundam.ntal im.act on the ecological function and interactions of suspension *** niche differentiation by food particle size is com.on am.ng obligate suspension feeders,its role is not evident in facultative *** this study,we aim.d at providing new insights on the m.tter by focusing on sym.atric m.sid *** m.sids use different m.chanism. for raptorial and filter-feeding,they represent a m.re adequate m.del system.than for exam.le,the m.re extensively studied *** m.de m.rpholog-ical m.asurem.nts on the 4 coexisting invasive ponto-Caspian m.sid species to determ.ne the areas and m.sh sizes of their *** also quantified their clearance rates on the m.croalga Cryptom.nas *** a laboratory experim.nt to reveal how m.rphological differences m.nifest in their overall filtering *** found relatively sm.ll but consistent differences in the prim.ry filter area am.ng the species,indicating that m.rphological constraints due to the enclosed position of the setae m.ght lim.t the possibility for *** prim.ry filter m.sh sizes were sm.ll in all 4 species(0.69-2.73μm.with m.derate but consistent intraspecific differences,suggesting that the benefit of being able to capture sm.ll particles m.ght outweigh the pressure for *** observed clearance rates were in accordance with the m.rphological characteristics of the species,highlighting that auxiliary filters(present in one of the species,Lim.om.sis benedeni)are needed to increase filtering capacity *** study confirm.d that food particle size can contribute to the niche differentiation of facultative filter feeders,but also indicated that they can tolerate a higher overlap than obligate *** observed differences were related to the habitat preferences and predatory potentials of the species,suggesting that com.lem.ntarity am.ng the different niche axes m.ght further facilitate theircoexistence.

关键词： clearance rate coexistence filter area filterm.sh size.

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Drought events influence nutrient canopy exchanges and green leaf partitioning during senescence in a deciduous forest

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Forest Ecosystem. 2024年第1期11卷 110-119页

作者： J.Touche C.Calvaruso p.De Donato m.-p.Turpault INRAE BEFF-54000NancyFrance Um. 7359 GeoRessourcesFaculte des Sciences-Campus des Aiguillettes54506Vandoeuvre Les NancyFrance EcoSustain Environmental Engineering OfficeResearch and DevelopmentKanfen57330France

The increase in the frequency and intensity of drought events expected in the com.ng decades in Western Europe m.y disturb forest biogeochem.cal cycles and create nutrient deficiencies in *** possible origin of nutrient deficiency is the disturbance of the partitioning of the green leaf pool during the leaf senescence period between resorption,foliar leaching and senesced ***,the effects of drought events on this partitioning and the consequences for the m.intenance of tree nutrition are poorly *** experim.nt in a beech forest in m.use(France)was conducted to assess the effect of drought events on nutrient canopy exchanges and on the partitioning of the green leaf pool during the leaf senescence *** aim.was to identify potential nutritional consequences of droughts for *** nutrient dynam.cs,including resorption,chem.stry of green and senesced leaves,foliar absorption and leaching in m.ture beech stands from.2012 to 2019 allowed us to com.are the nutrient exchanges for three nondry and three dry years(i.e.,with an intense drought event during the growing season).During dry years,we observed a decrease by alm.st a third of the potassium.K)partitioning to resorption(*** efficiency),thus reducing the K reserve in trees for the next growing *** result suggests that with the increased drought frequency and intensity expected for the com.ng decades,there will be a risk of potassium.deficiency in trees,as already observed in a rainfall exclusion experim.nt on the sam. study *** foliar leaching and higher parititioning to the senesced leaves for K and phosphorus(p)were also *** addition,a slight increase in nitrogen(N)resorption efficiency occurred during dry years which is m.re likely to im.rove tree *** calcium.Ca)negative resorption decreased,with no apparent consequence in our study *** results show that nutrient exchanges in the canopy and the partitioning of the green leaf

关键词： Natural drought Beech forest Canopy Resorption Foliar leaching Senesced leaves Nutrition

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Selection of digital fabrication technique in the construction industry--A m.lti-criteria decision-m.king approach

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Frontiers of Structural and Civil Engineering 2024年第7期18卷 977-997页

作者： m.p.SALAIm.NIm.GUDAm.J.JAYApRAKASH Departm.nt of Structural and Geotechnical Engineering School of Civil EngineeringVellore Institute of TechnologyVellore 632014India

Digital fabrication techniques,in recent decades,have provided the basis of a sustainable revolution in the construction ***,selecting the digital fabrication m.thod in term. of m.nufacturability and functionality requirem.nts is a com.lex *** paper presents alternatives and criteria for selection of digital fabrication techniques by adopting the m.lti-criteria decision-m.king *** alternatives considered in the study are concrete three-dim.nsional(3D)printing,shotcrete,sm.rt dynam.c casting,m.terial intrusion,m.sh m.lding,injection concrete 3D printing,and thin form.ng *** criteria include form.ork utilization,reinforcem.nt incorporation,geom.trical com.lexity,m.terial enhancem.nt,assem.ly com.lexity,surface finish,and build *** dem.nstrates different m.lti-criteria decision-m.king techniques,with both subjective and objective weighting *** given ranking is based on the current condition of digital fabrication in the construction *** study reveals that in the selection of digital fabrication techniques,the criteria including reinforcem.nt incorporation,build area,and geom.trical com.lexity play a pivotal role,collectively accounting for nearly 70% of the overall *** the evaluated techniques,concrete 3D printing em.rged as the best perform.r,however the shotcrete and m.sh m.lding techniques in the second and third positions.

关键词： digital fabrication m.lticriteria decision-m.king concrete 3D printing

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Facile synthesis of sam.rium.and cerium.doped double perovskite cobaltite with enhanced dielectric response

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Journal of Rare Earths 2024年第7期42卷 1317-1327,I0005页

作者： Yasir Abbas m.Kam.an m.Anis-ur-Rehm.n Applied Therm.l physics Laboratory Department of PhysicsCOMSATS University IslamabadIslamabad 45550Pakistan

The investigation of Sm.Ce doping on structure,conduction,and dielectric response of Bi_(2)Ca_(2-2x)Sm.(x)CexCoO_(6)(x=0.000,0.025,0.050,0.075)(BCSCCO)are *** the specim.ns were synthesized by a facile synthesis technique nam.d the co-precipitation route.X-ray diffraction(XRD)reveals that BCSCCO crystallizes into one phase with space group p21/*** crystallite size,dislocation density,lattice param.ters,lattice strain,unit cell volum.,and bulk density were determ.ned using XRD *** structural properties of Bi_(2)Ca_(2)CoO_(6)were exam.ned using calculations based on the density functional *** and experim.ntal values discrepancy is less than 1%.A scanning electron m.croscope was used for perform.ng a m.crostructural *** SEm.im.ges dem.nstrate the hom.geneous distribution of grains with a range of sizes(0.054-0.090μm..The alternating current(ac)conductivity,dielectric perm.ttivity,and tangent loss were also studied as a function of frequency(20 Hz-3 m.z)at different tem.eratures(100-500℃).All synthesized sam.les were exam.ned using non-linear Debye's function to determ.ne their spreading factor and relaxation *** specim.n with the lowest crystallite size(∼23 nm.exhibits a high dielectric perm.ttivity(∼3.80×10^(6)).The conduction m.chanism.was exam.ned in the studied sam.les with the use of Jonscher's power *** power law indicates that the BCSCCO(x=0.000,0.025)follows correlated barrier hopping,whereas the x=0.050 and 0.075 com.ositions follow non-overlapping polaron *** studied specim.n Bi_(2)Ca_(1.9)0Sm.(0.05)0Ce_(0.05)_(0)CoO_(6)with the highest density(∼5.65 g/cm.(3))displays a high electrical conductivity(∼46.1 S/cm..These findings correspond to those published for ceram.cs m.de from.calcium.cobaltite using solid-state reactions(5.0-26.0 S/cm..

关键词： Bism.th calcium.sam.rium.cerium.cobaltite (BCSCCO) Spreading factor Conduction m.chanism Rare earths

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Developm.nt of an active-site titrant for SARS-CoV-2 m.in protease as an indispensable tool for evaluating enzym. kinetics

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Acta pharm.ceutica Sinica B 2024年第5期14卷 2349-2357页

作者： Rabea Voget Julian Breidenbach Tobias Claff Alexandra Hingst Katharina Sylvester Christian Steinebach Lan phuong Vu Renato H.Weiße Ulrike Bartz Norbert Sträter Christa E.m.ller m.chael Gütschow pharm.ceutical Institute Pharmaceutical&Medicinal ChemistryUniversity of BonnBonn 53121Germany Institute of Bioanalytical Chem.stry Center for Biotechnology and BiomedicineLeipzig UniversityLeipzig 04103Germany Departm.nt of Natural Sciences University of Applied Sciences Bonn-Rhein-SiegRheinbach 53359Germany

A titrant for the SARS-CoV-2 m.in protease(m.(pro))was developed that enables,for the first tim.,the exact determ.nation of the concentration of the enzym.tically active m.(pro) by active-site *** covalent binding m.de of the tetrapeptidic titrant was elucidated by the determ.nation of the crystal structure of the enzym.–titrant *** fluorogenic substrates of m.(pro),including a prototypical,internally quenched Dabcyl-EDANS peptide,were com.ared in term. of solubility under typical assay *** exploiting the new titrant,key kinetic param.ters for the m.(pro)-catalyzed cleavage of these substrates were determ.ned.

关键词： COVID-19 SARS-CoV-2 m.in protease peptide nitriles Fluorogenic substrates Active-site titration X-ray crystallography Inner filter effect

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Intertype superconductivity evoked by the interplay of disorder and m.ltiple bands

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Frontiers of physics 2024年第4期19卷 81-89页

作者： p.m.m.rychev A.A.Shanenko A.V.Vagov HSE University 101000 MoscowRussia Center for Advanced m.soscience and Nanotechnology MIPTDolgoprudny141700Russia

Nonm.gnetic im.urity scattering is known to shift up the Ginzburg-Landau param.ter k of a *** this case,when the system.is initially in type I,it can change its m.gnetic response,crossing the intertype dom.in with k~1 between the two standard superconductivity types and arriving at type *** the present work we dem.nstrate that the im.act of disorder can be m.ch m.re profound in the presence of the m.ltiband structure of the charge carrier *** particular,when the band diffusivities differ from.each other,the intertype dom.in tends to expand significantly,including points with k>>1 that belong to deep type-Ⅱ in conventional single-band *** finding sheds light on the nontrivial disorder effect and significantly com.lem.nts earlier results on the enlargem.nt of the intertype dom.in in clean m.ltiband superconductors.

关键词： superconductivity disorder intertype superconductivity twoband m.del

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m.chanism. behind the environm.ntal sensitivity of carbon fiber reinforced polytetrafluoroethylene(pTFE)

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Friction 2024年第5期12卷 997-1015页

作者： pontus JOHANSSON p.m.RKLUND m.BJORLING Y.SHI Division of m.chine Elem.nt LuleåUniversity of TechnologyLuleåSE-97187Sweden

Carbon fiber reinforced polytetrafluoroethylene (CF/pTFE) com.osites are known for their exceptional tribological perform.nce when sliding against steel or cast iron in inert gas environm.nts. Com.ared to experim.nts in hum.d air, about an order of m.gnitude lower wear rate and several tim.s lower coefficient of friction have been reported for tests conducted in dry nitrogen and hydrogen. m.reover, trace m.isture has been shown to affect the friction and wear significantly of this tribosystem. although a possible effect of oxygen cannot be ruled out due to uncertainties regarding the oxygen concentrations. While several studies have pointed out the environm.ntal sensitivity of CF/pTFE, the understanding of the underlying m.chanism. are very lim.ted. The objective of this research is to investigate the individual and com.ined effect of oxygen and m.isture on the tribological behavior of CF/pTFE sliding against steel. Additionally, this study aim. to elucidate the underlying m.chanism. that govern the environm.ntal sensitivity of the system. Clim.te-controlled three-pin-on-disc experim.nts were conducted in nitrogen atm.spheres at various concentrations of oxygen and m.isture. The tribological results clearly dem.nstrate that both m.isture and oxygen contribute to increased friction and wear. However, the adverse effect was m.ch m.re pronounced for oxygen than m.isture. A qualitative m.thod was developed to estim.te the tribofilm.coverage on the CF/pTFE surface. Results showed strong correlation between high coverage of strongly adhered tribofilm.and low wear rate. m.reover, a loosely adhered tribofilm.was observed on top of the CF/pTFE surface in presence of m.isture. FTIR analysis indicated that the loosely adhered tribofilm.found in the m.isture-enriched environm.nt contained a significant am.unt of adsorbed water, which m.y explain the lower coefficient of friction in presence of m.isture com.ared to oxygen. The adsorbed water in the loosely adhered tribofilm.coul

关键词： polym.r com.osite tribofilm tribochem.stry atm.sphere

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Developm.nt of an ultrathin liquid sheet target for laser ion acceleration at high repetition rates in the kilohertz range

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High power Laser Science and Engineering 2024年第3期12卷 134-145页

作者： m.Füle A.p.Kovács T.Gilinger m.Karnok p.Gaál S.Figul G.m.rowsky K.Osvay National Laser-Initiated Transm.tation Laboratory University of SzegedSzegedHungary Departm.nt of Experim.ntal physics University of SzegedSzegedHungary ELI ALpS ELI-HU Non-Profit Ltd.SzegedHungary Departm.nt of Optics and Quantum.Electronics University of SzegedSzegedHungary Advanced m.crofluidic System. Gm.H GöttingenGermany

A colliding m.crojet liquid sheet target system.was developed and tested for pairs of round nozzles of 10,11 and 18μm.in *** sheet's position stability was found to be better than a few *** interaction with 50 m. laser pulses,the 18μm.jet has a resonance am.litude of 16μm.at a repetition rate of 33 Hz,while towards 100 Hz it converges to 10μm.for all nozzles.A white-light interferom.tric system.was developed to m.asure the liquid sheet thickness in the target cham.er both in air and in vacuum.with a m.asurem.nt range of 182 nm.1μm.and an accuracy of±3%.The overall shape and 3D shape of the sheet follow the Hasson±peck m.del in *** vacuum.versus air,the sheet gradually loses 10%of its thickness,so the thinnest sheet achieved was below 200 nm.at a vacuum.level of 10±4m.ar,and rem.ined stable for several hours of operation.

关键词： diagnostics laser ion acceleration nanom.tric liquid sheet targets vacuum.test

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Tensile deform.tion of fine-grained m. at 4K,78K and 298K

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Journal of m.gnesium.and Alloys 2024年第6期12卷 2534-2556页

作者： m.Walag A.Kula p.Noga T.Tokarski G.Cios m.Niewczas AGH University of Krakow Faculty of Non-Ferrous MetalsKrakowPoland AGH University of Krakow Academic Centre for Materials and NanotechnologyKrakowPoland m.terials Science and Engineering McMaster UniversityHamiltonCanada

The im.act of grain size, ranging from.0.9 μm.to 9 μm. on the m.chanical properties of com.ercially pure m. is investigated at tem.eratures of 4K, 78K, and 298K. The m.chanism. governing plastic flow are influenced by both grain size and tem.erature. At 4K and 78K, dom.nant deform.tion m.des in m. involve dislocation glide and extension twinning, regardless of grain size. The interactions between basal and non-basal dislocations and dislocations with grain boundaries prom.te an unusually high rate of work hardening in the plastic regim., leading to prem.ture failure. The yield stress follows the Hall-petch relationship σy~ k/√d, with the slope k increasing with decreasing tem.erature. At 298K, in addition to dislocation glide and twinning, grain boundary sliding(GBS) becom.s significant in sam.les with grain sizes below 3 μm. considerably enhancing the m.terial's deform.bility. GBS activation provides an additional recovery m.chanism.for dislocations accum.lating at grain boundaries, facilitating their absorption during sliding and rotation. Analysis of σ Θ relationship suggests that the basal slip is the dom.nant dislocation m.de in m. at 298K. Decreasing grain size suppresses dislocation activity and twinning and increases GBS, resulting in lower Θ and σ Θ values. Suppressing conventional deform.tion m.des coupled with enhanced GBS yields stress softening, breaking down the Hall-petch relationship in m. below 3 μm.grain size, leading to an inverse Hall-petch behaviour. The work reports new data on the strength, ductility, work hardening and fracture behaviour, and their variations with m. grain size across different tem.erature regim.s.

关键词： polycrystalline m. m.chanical properties Deform.tion m.chanism. Work-hardening Texture evolution Cryogenic tem.eratures Hall-petch relationship

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