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Comparative analysis of microstructure,mechanical,and corrosion properties of biodegradable mg-3Y alloy prepared by selective laser melting and spark plasma sintering

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journal of magnesium and Alloys 2024年第4期12卷 1496-1510页

作者： P.minárik m.Zemková S.Šašek j.Dittrich m.Knapek F.Lukáˇc D.Koutný j.jaroš R.Král Faculty of mathematics and Physics Charles UniversityKe Karlovu 5Praha 12116Czech Republic Research Centre University ofŽilinaUniverzitná8215/1Žilina 01026Slovakia Institute of Plasma Physics of the Czech Academy of Sciences Za Slovankou 1782/318200 Praha 8Czech Republic Institute of machine and Industrial Design Brno University of TechnologyTechnická2896/2Brno 61669Czech Republic

This work explored possibilities of biodegradable magnesium alloy mg-3Y preparation by two modern powder metallurgy techniques–spark plasma sintering(SPS)and selective laser melting(SLm).The powder material was consolidated by both methods utilising optimised parameters,which led to very low porosity(∼0.3%)in the SLm material and unmeasurably low porosity in the SPS *** main aim of the study was the thorough microstructure characterisation and interrelation between the microstructure and the functional properties,such as mechanical strength,deformability,and corrosion *** materials showed comparable strength of∼110 mPa in tension and compression and relatively good deformability of∼9%and∼21%for the SLm and SPS materials,*** corrosion resistance of the SPS material in 0.1 m NaCl solution was superior to the SLm one and comparable to the conventional extruded *** digital image correlation during loading and the cross-section analysis of the corrosion layers revealed that the residual porosity and large strained grains have the dominant negative effect on the functional properties of the SLm *** the other hand,one of the primary outcomes of this study is that the SPS consolidation method is very effective in the preparation of the W3 biodegradable alloy,resulting in material with convenient mechanical and degradation properties that might find practical applications.

关键词： magnesium Yttrium Powder metallurgy microstructure mechanical strength Corrosion resistance

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Supposition of graphene stacks to estimate the contact resistance and conductivity of nanocomposites

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Applied mathematics and mechanics(English Edition) 2024年第4期45卷 663-676页

作者： Y.ZARE m.T.mUNIR G.j.WENG K.Y.RHEE Biomaterials and Tissue Engineering Research Group Department of Interdisciplinary TechnologiesBreast Cancer Research CenterMotamed Cancer InstituteTehran ***Iran College of Engineering and Technology American University of the Middle EastEgaila 54200Kuwait Department of mechanical and Aerospace Engineering Rutgers UniversityNew BrunswickNJ 08903U.S.A. Department of mechanical Engineering(BK21 Four) College of EngineeringKyung Hee UniversityYongin 446701Republic of Korea

In this study,the effects of stacked nanosheets and the surrounding interphase zone on the resistance of the contact region between nanosheets and the tunneling conductivity of samples are evaluated with developed equations superior to those previously *** contact resistance and nanocomposite conductivity are modeled by several influencing factors,including stack properties,interphase depth,tunneling size,and contact *** developed model's accuracy is verified through numerous experimental *** further validate the models and establish correlations between parameters,the effects of all the variables on contact resistance and nanocomposite conductivity are ***,the contact resistance is primarily dependent on the polymer tunnel resistivity,contact area,and tunneling *** dimensions of the graphene nanosheets significantly influence the conductivity,which ranges from 0 S/m to90 S/*** increased number of nanosheets in stacks and a larger gap between them enhance the nanocomposite's ***,the thicker interphase and smaller tunneling size can lead to higher sample conductivity due to their optimistic effects on the percolation threshold and network efficacy.

关键词： graphene polymer composite stacked nanosheet tunneling conductivity contact resistance interphase

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Corrosion testing of X52 and X80 steels immersed in stimulated emulsions using a real petroleum sample

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Petroleum Research 2024年第2期9卷 304-316页

作者： L.m.Quej-Ake j.L.Alamilla A.Contreras Instituto mexicano del Petróleo Eje Central Lázaro CárdenasNorte 152San Bartolo AtepehuacanGustavo A.MaderoCiudad de MéxicoC.P.07730México

The aim of this study is to evaluate the internal corrosion process on X52 and X80 steels/real petroleum interfaces containing condensed hydrocarbon plus oilfield-produced water,which were subjected to stimulated emulsions using 50/50 vol ratio mixtures at 45℃,different hydrodynamic conditions,1 h,and 24 h.A washing process by using deionized water was proposed to simulate and identify the corrosiveness of the hydrocarbon phase after 24 h of exposure *** characterization by electrochemical impedance spectroscopy and the monitoring of the polarization curves indicated that X80 steel/oilfield-produced water interfaces were more susceptible to corrosion than X52 steel exposed to oilfield-produced *** combined speed rotation of 600 rpm using a magnetic stirrer+600 rpm using a rotating disk electrode decreased the corrosion rate on X52 *** stimulated emulsions made of hydrocarbon+oilfield-produced water and hydrocarbon+deionized water at 24 h increased the corrosion rate on X80 steel(0.34 mm/year and 0.43 mm/year,respectively),promoting the formation of erosion and pitting *** types of corrosion depended mainly on the physicochemical properties of the hydrocarbon,oilfield-produced water,exposure times,and hydrodynamic systems in which the hydrocarbon was studied.

关键词： Corrosion Emulsions X52 steel X80 steel

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High resolution sequence stratigraphy of the mishrif Formation(Cenomanian-Early Turonian)at zubair oilfield(al-rafdhiah dome),southern Iraq

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Petroleum Research 2024年第1期9卷 61-71页

作者： Aymen A.Lazim maher j.Ismail maher m.mahdi Geoscience Department Zubair Field Operation DivisionBasra Oil CompanyIraq Basrah Oil Company WQ1 FODBasrahIraq University of Basrah College of ScienceGeology Dept.BasrahIraq

The mishrif Formation(Cenomanian-E Turonian)is one of the most important geological formations in the middle East and Iraq because it contains enormous petroleum *** is considered to be the first reservoir in the region,and is still being studied because of its economic *** carbonate of the mishrif Formation derives from a variety of depositional settings,including mid-ramp,shoal,lagoon,and *** five main microfacies discussed in this paper are wackestone,packstone,grainstone,floatstone,and *** most frequent fossilised components found in the mishrif Formation are rudists,benthic foraminifera,echinoderms,burrows molluscs,and *** to the microfacies and analysed wireline log data,the sequence stratigraphy of the studied formation is composed of two regression *** parasequences of transgressive-regressive cycles make up the depositional sequence of the mishrif *** standard depositional environments seem to demonstrate a gradual regression,beginning with a short period of the outer ramp,then a steady period of the mid-ramp,and ending in the intertidal ***,the study recorded two regional maximum flooding surfaces:K-135 and *** former is present in the lowermost part of the formation,while the other lies in the *** study shows a close relationship between facies(environments)and hydrocarbon *** increased accumulation focuses on the lower part of the studied formation,and seems to be lower in the upper part of the formation as a result of changes in the environment of deposition.

关键词： mishrif formation Cenomanian Sequence stratigraphy Zubair oilfield Iraq

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modelling dynamic pantograph loads with combined numerical analysis

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Railway Engineering Science 2024年第1期32卷 81-94页

作者： F.F.jackson R.mishra j.m.Rebelo j.Santos P.Antunes j.Pombo H.magalhaes L.Wills m.Askill School of Computing and Engineering University of HuddersfieldHuddersfieldUK School of Computing and Engineering Institute of Railway ResearchUniversity of HuddersfieldHuddersfieldUK IDmEC Instituto Superior TecnicoUniversidade de LisboaLisbonPortugal ISEL Instituto Politecnico de LisboaLisbonPortugal Hitachi Rail Newton AycliffeUK Wabtec/Brecknell Willis ChardUK

Appropriate interaction between pantograph and catenary is imperative for smooth operation of electric *** heights of overhead lines to accommodate level crossings,overbridges,and tunnels pose significant challenges in maintaining consistent current collection performance as the pantograph aerodynamic profile,and thus aerodynamic load changes significantly with operational *** research aims to analyse the global flow characteristics and aerodynamic forces acting on individual components of an HSX pantograph operating in different configurations and orientations,such that the results can be combined with multibody simulations to obtain accurate dynamic insight into contact ***,computational fluid dynamics simulations are used to investigate the pantograph component loads in a representative setting,such as that of the recessed cavity on a Class 800 *** an aerodynamic perspective,this study indicates that the total drag force acting on non-fixed components of the pantograph is larger for the knuckle-leading orientation rather than the knuckle-trailing,although the difference between the two is found to reduce with increasing pantograph *** the aerodynamic loads acting on individual components with multibody tools allows for realistic dynamic insight into the pantograph *** results obtained show how considering aerodynamic forces enhance the realism of the models,leading to behaviour of the pantograph-catenary contact forces closely matching that seen in experimental tests.

关键词： Pantograph-catenary interaction Pantograph aerodynamics Computational fluid dynamics Pantograph loads Current collection performance

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Generation of polarized electron beams through self-injection in the interaction of a laser with a pre-polarized plasma

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High Power Laser Science and Engineering 2024年第3期12卷 62-68页

作者： L.R.Yin X.F.Li Y.j.Gu N.Cao Q.Kong m.Büscher S.m.Weng m.Chen Z.m.Sheng Key Laboratory of Nuclear Physics and Ion-beam Application(moE) Institute of Modern PhysicsDepartment of Nuclear Science and TechnologyFudan UniversityShanghaiChina State Key Laboratory of High Field Laser Physics Shanghai Institute of Optics and Fine MechanicsChinese Academy of SciencesShanghaiChina SANKEN(Institute of Scientific and Industrial Research) Osaka UniversityOsakaJapan Sichuan Research Institute Shanghai Jiao Tong UniversityChengduChina Peter Grünberg Institut(PGI-6) Forschungszentrum JülichJülichGermany Institut für Laser-und Plasmaphysik Heinrich-Heine-Universität DüsseldorfDüsseldorfGermany Key Laboratory for Laser Plasmas(moE) School of Physics and AstronomyShanghai Jiao Tong UniversityShanghaiChina Collaborative Innovation Center of IFSA Shanghai Jiao Tong UniversityShanghaiChina Tsung-Dao Lee Institute Shanghai Jiao Tong UniversityShanghaiChina

Polarized electron beam production via laser wakefield acceleration in pre-polarized plasma is investigated by particlein-cell *** evolution of the electron beam polarization is studied based on the Thomas±Bargmann±michel±Telegdi equation for the transverse and longitudinal self-injection,and the depolarization process is found to be influenced by the injection *** the case of transverse self-injection,as found typically in the bubble regime,the spin precession of the accelerated electrons is mainly influenced by the ***,in the case of longitudinal injection in the quasi-1D regime(for example,*** et al.,***.110,135002(2013)),the direction of electron spin oscillates in the laser *** the electrons move around the laser axis,the net influence of the laser field is nearly zero and the contribution of the wakefield can be ***,an ultra-short electron beam with polarization of 99%can be obtained using longitudinal self-injection.

关键词： laser wakefield acceleration longitudinal self-injection particle-in-cell simulation polarized electron beam

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Oryza CLImtools:A genome–environment association resource reveals adaptive roles for heterotrimeric G proteins in the regulation of rice agronomic traits

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Plant Communications 2024年第4期5卷 145-165页

作者： Angel Ferrero-Serrano David Chakravorty Kobie j.Kirven Sarah m.Assmann Biology Department Pennsylvania State University208 Mueller LaboratoryUniversity ParkPA 16802USA Intercollege Graduate Degree Program in Bioinformatics and Genomics Pennsylvania State University208 Mueller LaboratoryUniversity ParkPA 16802USA

modern crop varieties display a degree of mismatch between their current distributions and the suitability of the local climate for their *** address this issue,we present Oryza CLImtools(https://***/CLImtools/oryza_v1.0/),thefirst resource for pan-genome prediction of climate-associated genetic variants in a crop *** CLImtools consists of interactive web-based databases that enable the user to(1)explore the local environments of traditional rice varieties(landraces)in South-East Asia and(2)investigate the environment by genome associations for 658 Indica and 283 japonica rice landrace accessions collected from georeferenced local environments and included in the 3K Rice Ge-nomes *** demonstrate the value of these resources by identifying an interplay betweenflowering time and temperature in the local environment that is facilitated by adaptive natural variation in OsHD2 and disrupted by a natural variant in *** quantitative trait locus analysis has suggested the impor-tance of heterotrimeric G proteins in the control of agronomic ***,we analyzed the climate associations of natural variants in the different heterotrimeric G protein *** identified a coordi-nated role of G proteins in adaptation to the prevailing potential evapotranspiration gradient and revealed their regulation of key agronomic traits,including plant height and seed and panicle *** conclude by highlighting the prospect of targeting heterotrimeric G proteins to produce climate-resilient crops.

关键词： Oryza sativa rice G by E adaptation flowering time GWAS OsHD2 OsSOC1 heterotrimeric G pro-tein OsRGA1 d1 OsGS3 OsDEP1 OsGGC2

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Threshold-Based Software-Defined Networking(SDN)Solution for Healthcare Systems against Intrusion Attacks

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Computer modeling in Engineering & Sciences 2024年第2期138卷 1469-1483页

作者： Laila m.Halman mohammed j.F.Alenazi Department of Computer Engineering College of Computer ScienceKing Saud UniversityRiyadh11451Saudi Arabia

The healthcare sector holds valuable and sensitive *** amount of this data and the need to handle,exchange,and protect it,has been increasing at a fast *** to their nature,software-defined networks(SDNs)are widely used in healthcare systems,as they ensure effective resource utilization,safety,great network management,and *** this sector,due to the value of thedata,SDNs faceamajor challengeposed byawide range of attacks,such as distributed denial of service(DDoS)and probe *** attacks reduce network performance,causing the degradation of different key performance indicators(KPIs)or,in the worst cases,a network failure which can threaten human *** can be significant,especially with the current expansion of portable healthcare that supports mobile and wireless devices for what is called mobile health,or *** this study,we examine the effectiveness of using SDNs for defense against DDoS,as well as their effects on different network KPIs under various *** propose a threshold-based DDoS classifier(TBDC)technique to classify DDoS attacks in healthcare SDNs,aiming to block traffic considered a hazard in the form of a DDoS *** then evaluate the accuracy and performance of the proposed TBDC *** technique shows outstanding performance,increasing the mean throughput by 190.3%,reducing the mean delay by 95%,and reducing packet loss by 99.7%relative to normal,with DDoS attack traffic.

关键词： Network resilience network management attack prediction software defined networking(SDN) distributed denial of service(DDoS) healthcare

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In vivo and in vitro study of resorbable magnesium wires for medical implants:mg purity,surface quality,Zn alloying and polymer coating

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journal of magnesium and Alloys 2024年第6期12卷 2472-2488页

作者： K.Tesar j.Luňácková m.jex m.Žaloudková R.Vrbová m.Bartoš P.Klein L.Vištejnová j.Dušková E.Filová Z.Sucharda m.Steinerová S.Habr K.Balík A.Singh Department of materials Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueTrojanova 13Prague 12000Czech Republic Institute of Physics Czech Academy of SciencesNa Slovance 2Prague 18221Czech Republic Institute of Dental medicine First Faculty of MedicineCharles University and General University Hospital in PragueKaterinská32Prague 12801Czech Republic Department of Physics Faculty of Nuclear Sciences and Physical EngineeringCzech Technical University in PragueBrehová7Prague 11519Czech Republic Department of Composites and Carbon materials Institute of Rock Structure and MechanicsCzech Academy of SciencesV Holešovickách 41Prague 18209Czech Republic Institute of Anatomy First Faculty of MedicineCharles UniversityU Nemocnice 3Prague 12800Czech Republic Biomedical Center Faculty of Medicine in PilsenCharles UniversityAlej Svobody 76Pilsen 32300Czech Republic Department of Pathological Physiology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Department of Histology and Embryology Faculty of Medicine in PilsenCharles UniversityAlej Svobody 7632300 PilsenCzech Republic Institute of Pathology First Faculty of MedicineCharles University and General University Hospital in PragueStudnickova 2Prague 12800Czech Republic Department of Biomaterials and Tissue Engineering Institute of PhysiologyCzech Academy of SciencesVidenska 1083Prague 14200Czech Republic Research Center for Structural materials National Institute for Materials Science1-2-1 SengenTsukuba 305-0047Japan

magnesium is an excellent material in terms of biocompatibility and its corrosion products can serve as an active source for new bone ***,localized corrosion and H_(2)generation limit the potential of mg-based *** low-alloyed mg-Zn wires can strongly reduce problems with large H_(2)bubbles and improve the mechanical properties considerably while maintaining excellent long-term *** pickling and a polymer coating can be effectively used to lower the rate of in vivo *** this work,microstructural,mechanical,and in vitro characterization of 250μm and 300μm extruded wires made from ultra-pure mg,commercially pure mg,mg-0.15Zn,mg-0.4Zn and mg-1Zn was ***,mg-0.4Zn wires together with a variant coated with a copolymer of L-lactide andε-caprolactone were tested in vivo on artificially damaged Wistar rat *** on the observed mg-induced osteogenesis,polymer-coated mg wires with a small addition of Zn are a perspective material for bone-support applications,such as cerclage and fixation wires.

关键词： magnesium Resorbable mg wire mg-Zn implant degradation Biocompatibility study Zn grain boundary segregation

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Fever assessment in children under five: Are we following the guidelines?

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World journal of Clinical Pediatrics 2024年第1期13卷 62-72页

作者： Hasan m Isa Ahmed j Isa murtadha A Alnasheet mahmood m mansoor Department of Pediatrics Salmaniya Medical ComplexManama 26671Bahrain Department of Pediatrics Arabian Gulf UniversityManama 26671Bahrain Department of General Surgery Salmaniya Medical ComplexManama 26671Bahrain

BACKGROUND Fever is a common cause of medical consultation and hospital admission,particularly among ***,the United Kingdom’s National Institute for Health and Care Excellence(NICE)updated its guidelines for assessing fever in children under five years of *** efficient assessment and management of children with fever are crucial for improving patient *** To evaluate fever assessment in hospitalized children and to assess its adherence with the NICE Fever in under 5s *** We conducted a retrospective cohort review of the electronic medical records of children under five years of age at the Department of Pediatrics,Salmaniya medical Complex,Bahrain,between june and july *** data,vital signs during the first 48 h of admission,route of temperature measurement,and indications for admission were *** was defined according to the NICE *** children were divided into five groups according to their age(0-3 months,>3-6 months,>6-12 months,>12-36 months,and>36-60 months).Patients with and without fever were compared in terms of demography,indication for admission,route of temperature measurement,and other vital *** with the NICE Fever in the under 5s guideline was *** compliance was defined as>95%,partial compliance as 70%-95%,and minimal compliance as≤69%.Pearson’sχ^(2),Student’s t test,the mann-Whitney U test,and Spearman’s correlation coefficient(rs)were used for *** Of the 136 patients reviewed,80(58.8%)were *** median age at admission was 14.2[interquartile range(IQR):1.7-44.4]months,with the most common age group being 36-60 ***-six(26.4%)patients had fever,and 100(73.6%)were *** commonest age group for febrile patients(>12-36 months)was older than the commonest age group for afebrile patients(0-3 months)(P=0.027).The median weight was 8.3(IQR:4.0-13.3)*** with fever had higher weight than those without fever[10.2(IQR:7.3-13.0)vs 7

关键词： Fever Pediatrics Admission patterns Temperature measurement Guidelines Bahrain

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