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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 com.ression 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 prim.ry 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

Adaptation in brain structure and respiratory and olfactory structures across environmental gradients in African and North Am.rican m.roid rodents

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Integrative Zoology 2024年第1期19卷 165-181页

作者： Peter J.TAYLOr Aluwani NeNGOVHeLA Christiane DeNYS Graham.r.SCOTT Catherine m.IVY Department of Zoology School of Natural and Mathematical SciencesUniversity of VendaThohoyandouSouth Africa Afromontane Unit Department of Zoology and EntomologyUniversity of the Free StatePhuthaditjhabaSouth Africa Department of mammalogy National MuseumBloemfonteinSouth Africa Institut de Systématique EvolutionBiodiversité(ISYEB)Muséum National d’Histoire NaturelleCNRSSorbonne UniversitéEPHEUniversitéDes AntillesParisFrance Department of Biology McMaster UniversityHamiltonOntarioCanada Guglielmo and Shoemaker Labs Advanced Facility for Avian ResearchUniversity of Western OntarioLondonOntarioCanada

m.rphometric studies of 3D micro CT-scanned images can provide insights into the evolution of the brain and sensory structures but such data are still scarce for the most diverse mammalian order of *** reviewed and new data,we tested for convergence to extreme aridity and high elevation in the sensory and brain m.rphology of rodents,from m.rphometric data from micro-CT X-ray scans of 174 crania of 16 species of three distantly re-lated African m.rid(soft-furred mice,Praomyini,laminate-toothed rats,Otomyini,and gerbils,Gerbillinae)clades and one North Am.rican cricetid(deer mice and white-footed mice,Peromyscus)*** studies demon-strated convergent evolution acting on the oval window area of the cochlea(enlarged in extremely arid-adapted species of Otomyini and Gerbillinae)and on endocranial volume(reduced in high elevation taxa of Otomyini and Peromyscus).However,contrary to our predictions,we did notfind evidence of convergence in brain struc-ture to aridity,or in the olfactory/respiratory system(turbinate bones)to high *** structure differed,particularly in the petrosal lobules of the cerebellum and the olfactory bulbs,between Otomyini and Gerbillinae,with extreme arid-adapted species in each clade being highly divergent(not convergent)from other species in the same *** observed greater“packing”of the maxillary turbinate bones,which have important respiratory functions,in Peromyscus mice from high and low elevations compared to the high-elevation African Praomyini,but m.re complex patterns within Peromyscus,probably related to trade-offs in respiratory physiology and heat exchange in the nasal epithelium associated with high-elevation adaptation.

关键词： 3D m.rphometrics Africa brain size North Am.rica rodentia sensory evolution

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.Kamran m.Anis-ur-rehman Applied Thermal 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 specimens were synthesized by a facile synthesis technique named the co-precipitation route.X-ray diffraction(XrD)reveals that BCSCCO crystallizes into one phase with space group P21/*** crystallite size,dislocation density,lattice parameters,lattice strain,unit cell volume,and bulk density were determined using XrD *** structural properties of Bi_(2)Ca_(2)CoO_(6)were examined using calculations based on the density functional *** and experimental values discrepancy is less than 1%.A scanning electron microscope was used for performing a microstructural *** Sem images demonstrate the homogeneous distribution of grains with a range of sizes(0.054-0.090μm).The alternating current(ac)conductivity,dielectric permittivity,and tangent loss were also studied as a function of frequency(20 Hz-3 mHz)at different temperatures(100-500℃).All synthesized samples were examined using non-linear Debye's function to determine their spreading factor and relaxation *** specimen with the lowest crystallite size(∼23 nm)exhibits a high dielectric permittivity(∼3.80×10^(6)).The conduction mechanism was examined in the studied samples 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 compositions follow non-overlapping polaron *** studied specimen 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 ceramics made from calcium cobaltite using solid-state reactions(5.0-26.0 S/cm).

关键词： Bismuth calcium sam.rium cerium cobaltite (BCSCCO) Spreading factor Conduction mechanism rare earths

Ultrafast magneto-optical dynamics in nickel(111)single crystal studied by the integration of ultrafast reflectivity and polarimetry probes

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Chinese Physics B 2024年第3期33卷 65-69页

作者：匡皓余军潇陈洁 H.e.elsayed-Ali 李润泽 Peter m.rentzepis School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Center for Transformative Science ShanghaiTech UniversityShanghai 201210China Center for Ultrafast Science and Technology Key Laboratory for Laser Plasmas (Ministry of Education)Collaborative Innovation Center of IFSA (CICIFSA)School of Physics and AstronomyShanghai Jiao Tong UniversityShanghai 200240China Department of electrical and Computer engineering Old Dominion UniversityNorfolkVirginia 23529USA Department of electrical and Computer engineering Texas A&M UniversityCollege StationTexas 77843USA

With the integration of ultrafast reflectivity and polarimetry probes,we observed carrier relaxation and spin dynamics induced by ultrafast laser excitation of Ni(111)single *** carrier relaxation time within the linear excitation range reveals that electron-phonon coupling and dissipation of photon energy into the bulk of the crystal take tens of *** the other hand,the observed spin dynamics indicate a longer time of about 120 *** further understand how the lattice degree of freedom is coupled with these dynamics may require the integration of an ultrafast diffraction probe.

关键词： ultrafast spin dynamics non-equilibrium dynamics multi-probe

magnetic,dielectric and electrical modulus of Ce^(3+) doped cobalt-magnesium ferrite nanoparticles

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Journal of rare earths 2024年第2期42卷 373-382,I0005页

作者： N.m.Basfer Hanaa Almaghamsi Department of Physics Umm AL-Qura UniversityMakkahSaudi Arabia Physics Department College of Science and ArtKing Abdulaziz UniversityPOB344Rabigh291Saudi Arabi

In this work,the magnetic,dielectric properties and electric modulus of Ce^(3+) substituted cobaltmagnesium(Co_(0.7)mg_(0.3)Ce_(x)Fe_(2-x)O_4)(labeled as CmCF) ferrite nanoparticles were investigated in *** magnetization decreases from 50.05 to 34.87 emu/g for further substituting Ce^(3+) ***,coercivity increases from 738.22 Gs for the CmCFO sample to 912.10 Gs for the CmCF2 sample,then decreases monotonically to 762.1 Gs for the CmCF5 *** cerium content and particle size play important roles in controlling the magnetization and coercivity of the CmCF *** CmCF nanoferrites are suitable for microwave applications since their high-frequency response ranges from 7.72 to 11.07 *** CmCF nanoferrites' dielectric parameter dispersion exhibits normal *** pristine Co-mg nanoferrite only has ε' value of 28.25,but the nanoferrite mCmF2 has ε' value of365.03,with an enhancing ratio of 1192%.The conduction mechanism of the mCmF nanoferrites was determined by fitting the σ_(ac) results via the Jonscher power *** 653 K,large polaron tunnelling is thought to be responsible for this conduction process,which is followed by electron barrier hopping at higher ***-Cole diagrams at different temperatures,assuring the contributions of the grains and their boundaries at lower temperatures(653 K) and only the grains at higher *** on our results,the CmCF nanoferrites hold magnetic and semiconducting nature,which can be used in magnetic devices and dielectrics in lower-frequencies or conductors in higher-frequencies.

关键词： Nanoferrites rare earth ions magnetic properties Dielectric parameters Impedance spectroscopy

An Adaptive Hate Speech Detection Approach Using Neutrosophic Neural Networks for Social media Forensics

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Computers, materials & Continua 2024年第4期79卷 243-262页

作者： Yasmine m.Ibrahim.reem essameldin Saad m.Darwish Department of Information Technology Institute of Graduate Studies and ResearchAlexandria UniversityAlexandria21526Egypt Faculty of Computers and Information Technology Egyptian E-Learning University(EELU)Giza12611Egypt Faculty of Computers and Data Science Alexandria UniversityAlexandria21554Egypt

Detecting hate speech automatically in social media forensics has em.rged as a highly challenging task due tothe complex nature of language used in such platforms. Currently, several methods exist for classifying hatespeech, but they still suffer from ambiguity when differentiating between hateful and offensive content and theyalso lack accuracy. The work suggested in this paper uses a combination of the Whale Optimization Algorithm(WOA) and Particle Swarm Optimization (PSO) to adjust the weights of two multi-Layer Perceptron (mLPs)for neutrosophic sets classification. During the training process of the mLP, the WOA is employed to exploreand determine the optimal set of weights. The PSO algorithm adjusts the weights to optimize the performanceof the mLP as fine-tuning. Additionally, in this approach, two separate mLP models are employed. One mLPis dedicated to predicting degrees of truth membership, while the other mLP focuses on predicting degrees offalse membership. The difference between these memberships quantifies uncertainty, indicating the degree ofindeterminacy in predictions. The experimental results indicate the superior performance of our model comparedto previous work when evaluated on the Davidson dataset.

关键词： Hate speech detection whale optimization neutrosophic sets social media forensics

QCD sum.rule study of J^(P)=1^(±)exotic states with two heavy quarks in the molecular picture

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Chinese Physics C 2024年第6期48卷 31-37页

作者： T.m.Aliev S.Bilmis m.Savcı Department of Physics Middle East Technical UniversityAnkara06800Turkey TUBITAK ULAKBIm Ankara06510Turkey

In this study,the spectroscopic parameters of exotic molecular states composed of mesons containing two heavy quarks(scalar-axial and pseudoscalar-axial meson combinations)are investigated within the QCD sum *** findings reveal that molecular states containing charm quarks do not form bound states,whereas states with b-quarks can form exotic molecular *** observation has significant implications for understanding the structure of these exotic states.

关键词： QCD sum.rules exotic mesons molecular states

Ground-based and additional science support for SmILe

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earth and Planetary Physics 2024年第1期8卷 275-298页

作者： J.A.Carter m.Dunlop C.Forsyth K.Oksavik e.Donovon A.Kavanagh S.e.milan T.Sergienko r.C.Fear D.G.Sibeck m.Connors T.Yeoman X.Tan m.G.G.T.Taylor K.mcWilliams J.Gjerloev r.Barnes D.D.Billet G.Chisham A.Dimmock m.P.Freeman D.-S.Han m.D.Hartinger S.-Y.W.Hsieh Z.-J.Hu m.K.James L.Juusola K.Kauristie e.A.Kronberg m.Lester J.manuel J.matzka I.mcCrea Y.miyoshi J.rae L.ren F.Sigernes e.Spanswick K.Sterne A.Steuwer T.Sun m.-T.Walach B.Walsh C.Wang J.Weygand J.Wild J.Yan J.Zhang Q.-H.Zhang Planetary Sciences Group School of Physics and AstronomyUniversity of LeicesterUniversity RoadLeicesterLE17RHUK rutherford Appleton Laboratory Space Science Technology Facilities CouncilOxfordshireUK School of Space and environment Beihang UniversityBeijing 100191China Key Laboratory of Space environment monitoring and Information Processing Ministry of Industry and Information TechnologyBeijing 100017China Department of Space and Climate Physics UCLMullard Space Science LaboratoryHolmbury St.MaryDorkingSurreyRH56NTUK Birkeland Centre for Space Science Department of Physics and Technology.University of BergenBergenNorway Department of Physics and Astronomy University of Calgary2500 University DriveCalgaryAlbertaCanada T2N 1N4 British Antarctic Survey CambridgeUK Swedish Institute of Space Physics KirunaSweden West Highfield Campus University of SouthamptonUniversity RoadSO171BJUK Goddard Space Flight Center NASAGreenbeltMarylandUSA Athabasca University AthabascaCanada eSTeC European Space AgencyNetherlands University of Saskatchewan SaskatoonCanada The Johns Hopkins University Applied Physics Laboratory LaurelMarylandUSA Swedish Institude of Space Physics UppsalaSE 75121Sweden Tongji University Shanghai 200092China Center for Space Plasma Physics Space Science Institute4765 Walnut Street Suite BBoulderColorado80301USA Polar research Institute of China Shanghai 200136China Finnish meteorological Institute(FmI) Finland Department of earth and environmental Sciences(Geophysics) Ludwig Maximilian University of Munich(LMU)MunichTheresienstr.41MunichD-80333Germany Canadian Space Agency MontrealCanada GFZ German research Centre for Geosciences PotsdamGermany Nagoya University Institute for Space Earth Environment ResearchCenter for Integrated Data ScienceNagoyaAichiJP 464-8601 Northum.ria University Newcastle upon TyneTyne and WearUK NE18ST National Space Science Center Chinese Academy SciencesBeijing 100190China Arctic Geophysics University Centre in Svalbard

The joint european Space Agency and Chinese Academy of Sciences Solar wind magnetosphere Ionosphere Link explorer(SmILe)mission will explore global dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere *** these large-scale responses with medium and fine-scale measurements at a variety of cadences by additional ground-based and space-based instruments will enable a much greater scientific impact beyond the original goals of the SmILe ***,we describe current community efforts to prepare for SmILe,and the benefits and context various experiments that have explicitly expressed support for SmILe can offer.A dedicated group of international scientists representing many different experiment types and geographical locations,the Ground-based and Additional Science Working Group,is facilitating these *** include constructing an online SmILe Data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular observing strategies and spacecraft *** anticipate growing interest and community engagement with the SmILe mission,and we welcome novel ideas and insights from the solar-terrestrial community.

关键词： magnetosphere ionosphere magnetosphere-ionosphere coupling ground-based experimentation SmILe conjunctions missions

Cr-induced fusion reactions to synthesize superheavy elements

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Nuclear Science and Techniques 2024年第5期35卷 122-130页

作者： S.madhu H.C.manjunatha N.Sowmya B.m.rajesh L.Seenappa r.S.Susheela Department of Physics R V College of EngineeringBangalore 560074India Visvesvaraya Technological University BelagaviKarnataka 590018India Department of Physics Government First Grade CollegeSrinivasapurKarnataka 563135India Department of Physics Government First Grade CollegeDevanahallyKarnataka 562110India Department of Physics Government First Grade CollegeMulbagalKarnataka 563131India Department of Physics Government First Grade collegeNanjangudOoty RoadMysore 571301India

We investigated ^(50,52-54)Cr-induced fusion reactions for the synthesis of the superheavy element in the 104≤Z≤122 *** cross sections produced in this investigation using ^(54)Cr projectiles were compared with those obtained in prior *** estimated cross sections from this analysis are consistent with the findings of prior *** the current study,the predicted cross section was found to be 42fb at 236 meV for ^(53)Cr+^(243)Am,23.2 fb at 236 meV for ^(54)Cr+^(247)Cm,95.6 fb at 240 meV for ^(53)Cr+248Bk,and 1.33 fb at 242 meV for ^(53)Cr+***,these projected cross sections with excitation energy and beam energy will be useful in future Cr-induced fusion reaction investigations.

关键词： Fusion cross sections Compound nucleus formation probability Survival probability evaporation residue cross sections