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A STUDY OF CARBIDE GROWTh IN mAR-m247 LC ALLOY BY DIRECTIONAL SOLIDIFICATION mEThOD

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Acta metallurgica Sinica(English Letters) 1996年第6期9卷 509-514页

作者： J.h Lee J. Chen S.J. Choe Y.T. Lee and h.m. kim(high Temperature materials Laboratory, Korea Institute of machinery & materials, 66 Sangnam Dong,Changwon, Kyungnam,641010, Korea ) Korea Inst of machinery & Materials Changwon South Korea

The carbide growth behavior of mAR-m247 LC alloy was investigated by directional solidification and quench.m.thod. The carbide volume fraction, trapping and growth behavior were correlated with the growth *** was found that the carbide volume fraction decreased at slower growth *** decreasing was caused by lower solidliquid interface trapping ability at slower growth rate.

关键词： carbide,directional solidification,trapping growth

Free vibration and buckling analysis of polymeric composite beams reinforced by functionally graded bamboo fbers

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Applied math.m.tics and mechanics(English Edition) 2024年第3期45卷 543-562页

作者： h.m.FEIZABAD m.h.YAS Department of mechanical Engineering Razi UniversityKermanshah ***Iran

Natural fibers have been extensively researched as reinforcement materials in polymers on account of their environmental and economic advantages in comparison with synthetic fibers in the recent *** fibers are renowned for their good mechanical properties,abundance,and short cycle *** beams are one of the fundamental structural components and are susceptible to mechanical loads in engineering applications,this paper performs a study on the free vibration and buckling responses of bamboo fiber reinforced composite(BFRC)beams on the elastic *** different functionally graded(FG)layouts and a uniform one are the considered distributions for unidirectional long bamboo fibers across the *** elastic properties of the composite are determined with the law of *** h.m.lton’s principle,the governing equations of motion are *** generalized differential quadrature method(GDQm)is then applied to the equations to obtain the *** achieved outcomes exhibit that the natural frequency and buckling load values vary as the fiber volume fractions and distributions,elastic foundation stiffness values,and boundary conditions(BCs)and slenderness ratio of the beam ***,a comparative study is conducted between the derived analysis outcomes for BFRC and h.m.genous polymer beams to examine the effectiveness of bamboo fibers as reinforcement materials,demonstrating the significant enhancements in both vibration and buckling responses,with the exception of natural frequencies for cantilever beams on the Pasternak foundation with the FG-◇fiber ***,the obtained analysis results of BFRC beams are also compared with those for carbon nanotube reinforced composite(CNTRC)beams found in the literature,indicating that the buckling loads and natural frequencies of BFRC beams are lower than those of CNTRC beams.

关键词： bamboo fiber free vibration buckling analysis functionally graded(FG)beam elastic foundation generalized differential quadrature method(GDQm)

Superplasticity of fine-grained mg-10Li alloy prepared by severe plastic deformation and understanding its deformation mechanisms

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Journal of magnesium and Alloys 2024年第1期12卷 316-331页

作者： h.T.Jeong S.W.Lee W.J.kim Department of materials Science and Engineering Hongik UniversityMapo-guSangsu-dong 72-1Seoul 121-791Republic of Korea

The superplastic behavior and associated deformation mechanisms of a fine-grained mg-10.1 Li-0.8Al-0.6Zn alloy(LAZ1011)with a grain size of 3.2μm,primarily composed of the BCCβphase and a small amount of the hCPαphase,were examined in a temperature range of 473 K to 623 *** microstructural refinement of this alloy was achieved by employing high-ratio differential speed *** best superplasticity was achieved at 523 K and at strain rates of 10^(-4)-5×10^(-4)s^(-1),where tensile elongations of 550±600%were *** the heating and holding stage of the tensile samples prior to tensile loading,a significant increase in grain size was observed at temperatures above 573 ***,it was important to consider this effect when analyzing and understanding the superplastic deformation behavior and *** the investigated strain rate range,the superplastic flow at low strain rates was governed by lattice diffusion-controlled grain boundary sliding,while at high strain rates,lattice diffusion-controlled dislocation climb creep was the rate-controlling deformation *** was concluded that solute drag creep is unlikely to *** the late stages of deformation at 523 K,it was observed that grain boundary sliding led to the agglomeration of theαphase,resulting in significant strain *** mechanism maps were constructed forβ-mg-Li alloys in the form of 2D and 3D formats as a function of strain rate,stress,temperature,and grain size,using the constitutive equations for various deformation mechanisms derived based on the data of the current tests.

关键词： magnesium-lithium alloy Superplasticity Severe plastic deformation Grain size Grain growth

hyperreflective photonic crystals created by shearing colloidal dispersions at ultrahigh volume fraction

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microsystems & Nanoengineering 2024年第1期10卷 161-173页

作者： minji kim Jong Bin kim Shin-hyun kim Department of Ch.m.cal and Biomolecular Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea

Colloidal crystallization serves as one of the most economic and scalable production methods for photonic ***,insufficient optical performance,nonuniformity and low reproducibility remain challenges for advanced high-value *** this study,we optimally formulate a photocurable dispersion of silica particles and apply shear flow to unify the orientation of the colloidal crystals,ensuring high optical performance and *** silica particles experience strong repulsion at ultrahigh volume fractions of 50%but demonstrate low mobility,leading to polycrystalline *** shear flow to the dispersions allows the silica particles to rearrange into larger crystalline domains with a unidirectional orientation along the *** shear-induced structural change produces absolute reflectivity at the stopband as high as 90%and a high transparency of 90%at off-resonant wavelengths with.m.nimal diffusive ***,the strong interparticle repulsion ensures a uniform volume fraction of particles throughout the dispersion,reducing deviations in the optical *** intricately micropattern the photocurable dispersions using ***,the photonic films and patterns can be stacked to form multiple layers,displaying mixed structural colors and multiple reflectance peaks without sacrificing *** superior photonic materials hold promise for various optical applications,including optical components and anticounterfeiting patches.

关键词： properties. dispersion reflectivity

Boosted Lithium-Ion Transport Kinetics in n-Type Siloxene Anodes Enabled by Selective Nucleophilic Substitution of Phosphorus

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Nano-micro Letters 2024年第10期16卷 618-637页

作者： Se In kim Woong-Ju kim Jin Gu Kang Dong-Wan kim School of Civil Environmental and Architectural EngineeringKorea University02841 SeoulSouth Korea Nanophotonics Research Center Korea Institute of Science and Technology02792 SeoulSouth Korea

Doped two-dimensional(2D)materials hold significant promise for advancing many technologies,such as microelectronics,optoelectronics,and energy ***,n-type 2D oxidized Si nanosheets,namely n-type siloxene(n-SX),are employed as Li-ion battery *** thermal evaporation of sodium hypophosphite at 275℃,P atoms are effectively incorporated into siloxene(SX)without compromising its 2D layered morphology and unique Kautsky-type crystal ***,selective nucleophilic substitution occurs,with only Si atoms being replaced by P atoms in the O_(3)≡Si-h *** resulting n-SX possesses two delocalized electrons arising from the presence of two electron donor types:(i)P atoms residing in Si sites and(ii)h *** doping concentrations are varied by controlling the amount of precursors or their mean free *** at 2000 mA g^(-1),the n-SX electrode with the optimized doping concentration(6.7×10^(19) atoms cm^(-3))delivers a capacity of 594 mAh g^(-1) with a 73%capacity retention after 500 *** improvements originate from the enhanced kinetics of charge transport processes,including electronic conduction,charge transfer,and solid-state *** approach proposed herein offers an unprecedented route for engineering SX anodes to boost Li-ion storage.

关键词： Li-ion battery Two-dimensional N-type siloxene Doping mechanism Kinetics

Three cases of uncommon medication-associated osteonecrosis of temporal bone

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世界耳鼻咽喉头颈外科杂志英文版 2024年第03期10卷 237-240页

作者： VanDolah hunter Crossley Jason R. Jeffrey kim h. Georgetown University School of medicine Washington DC USA Department of Otolaryngology–head and Neck Surgery MedStar Georgetown University Hospital Washington DC USA

Introduction: medication-related osteonecrosis of the temporal bone is rare and has been reported to be associated with the use of anti-resorptive and biologic agents. here, we present the first case of tyrosine-kinase inhibitor-related external auditory canal (EAC) osteonecrosis as well as two cases related to anti-resorptive ***: A retrospective case ***: Case one: an 84-year-old female presented with chronic otitis externa and osteonecrosis of EACs bilaterally. She had a history of osteoporosis treated with denosumab and risedronic acid. She successfully underwent left EAC reconstruction using an inferiorly-based pedicle periosteal flap while the right ear canal was managed conservatively. Case two: a 69-year-old male presented with osteonecrosis of the right EAC. he had a history of osteoporosis treated with alendronic acid and zoledronic acid. his osteonecrosis is conservatively managed with local debridement and antibiotic application. Case three: a 60-year-old male presented with osteonecrosis of the right inferior EAC. he had a history of chronic myelogenous leukemia treated with a tyrosine-kinase inhibitor, imatinib. After failing conservative therapy, he underwent right ear canal reconstruction using a periosteal vascular pedicle flap without complication and experienced complete resolution to his ***: Anti-resorptive agents and/or tyrosine kinase inhibitors may lead to dysregulation of bone remodeling and result in rare cases of temporal bone osteonecrosis. When a local debridement and antibiotic therapy fail, definitive surgical excision of necrotic bone with subsequent reconstruction of the EAC may offer patients a possible resolution in symptoms.

关键词： bisphosphonates denosumab external auditory canal imatinib medication-related osteonecrosis osteonecrosis temporal bone tyrosine-kinase Inhibitors

ATP-binding cassette transporters as possible targets for the intervention of neurodegenerative diseases

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Neural Regeneration Research 2024年第4期19卷 721-722页

作者： hiu Chuen Lok Glenda m.halliday Woojin Scott kim Brain and mind Centre&School of medical Sciences The University of SydneySydneyNSWAustralia

ATP-binding cassette(ABC)transporters are ubiquitous membrane-bound proteins that are responsible for the translocation of a broad spectrum of substrates across cellular membranes,including lipids,amino acids,nucleosides,sugars,and ***,ABC transporters are highly expressed in the *** their functions in the brain still need to be elucidated,several members are implicated in the pathogenesis of neurodegenerative diseases,including Alzheimer’s disease(AD),Parkinson’s disease(PD),and frontotemporal *** this perspective,we will review current knowledge of ABC transporters in the central nervous system in terms of physiological functions and pathology in ***,we will explore the possibilities of ABC transporters as potential targets in the development of therapeutics for neurodegenerative diseases.

关键词： sugar degenerative diseases

Influence of erbium on structural,and charged particles,photons,and neutrons shielding properties of Ba_(1-x)Er_(x)SnO_(3) perovskite ceramics

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Journal of Rare Earths 2024年第4期42卷 724-732页

作者： m.K.h.h.m.d Nidal Dwaikat m.h.A.mhareb m.I.Sayyed R.m.h.m.d Y.S.m.Alajerami m.A.Almessiere Gameel Saleh Ahmad hussein Alomari K.A.Ziq Department of Basic Sciences School of Social and Basics SciencesAl Hussein Technical UniversityKing Abdullah II St 242Amman11831Jordan Department of Physics College of Engineering and PhysicsInterdisciplinary Research Center for Advanced MaterialsKing Fahd University of Petroleum&MineralsDhahran31261Saudi Arabia Department of Physics College of ScienceImam Abdulrahman Bin Faisal UniversityP.O.Box 1982Dammam31441Saudi Arabia Basic and Applied Scientific Research Center Imam Abdulrahman Bin Faisal UniversityP0.Box 1982Dammam31441Saudi Arabia Department of Physics Faculty of ScienceIsra UniversityAmman11622Jordan Department of Nuclear medicine Research Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Arabia medical Imaging Department Applied Medical Sciences FacultyAl Azhar University-Gaza CityPo.Box 1277Palestine Department of Biophysics Institute for Research and Medical Consultations(IRMC)Imam Abdulrahman Bin Faisal UniversityPo.Box1982Dammam 31441Saudi Arabia Department of Biomedical Engineering College of EngineeringImam Abdulrahman Bin Faisal UniversityPo.Box 1982Dammam31441Saudi Energy&minerals Regulatory Commission Amman11821Jordan

Five perovskite ceramics samples of Ba_(1-x)Er_(x)SnO_(3) with x=0.00,0.05,0.10,0.15,and 0.20 were synthesized using the conventional solid-state reaction *** prepared samples were characterized by X-ray diffraction(XRD),Fourier transforms infrared(FTIR),and UV-Vis *** shielding properties against ionizing radiation were also *** XRD analysis shows the perovskite cubic structure as the major phase in all *** FTIR reveals a distinctive band around 614-620 cm^(-1) ascribed to the antisymmetric O-Sn-O ***-Vis spectroscopy was used to determine the bandgap according to diffuse reflectance,and the results display a fixed enhancement in the bandgap from 3.2 to 3.3 eV for all ***-ray shielding properties of the synthesized samples were experimentally measured and compared with XCOm computational *** relative differences(Δ,%)between experimental and theo retical values are low and fall within the 0.446%-7.10%*** addition of Er leads to the enhanced density,neutron,and gamma shielding *** contrast,charged particles’shielding parameters gradually reduce with rising Er *** results suggest that Ba_(1-x)Er_(x)SnO_(3) samples can be used in different radiation shielding applications.

关键词： Perovskite Ceramics Gamma ray shielding mass stopping power Rare earths

Postmortem ^(7)Li NmR analysis for assessing the reversibility of lithium metal electrodes in lithium metal batteries

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Journal of Energy Ch.m.stry 2024年第7期94卷 430-440页

作者： Jaewon Baek Sunha kim hee-Tak kim Oc hee han Department of Ch.m.cal&Biomolecular Engineering KAISTDaejeon 34141Republic of Korea metropolitan Seoul Center Korea Basic Science InstituteSeoul 03759Republic of Korea Graduate School of Analytical Science&Technology Chungnam National UniversityDaejeon 34134Republic of Korea

Despite the proficiency of lithium(Li)-7 NmR spectroscopy in delineating the physical and ch.m.cal states of Li metal electrodes,challenges in specimen preparation and interpretation impede its *** this study,we conducted a comprehensive postmortem analysis utilizing ^(7)Li NmR,employing a stan-dard magic angle spinning probe to examine protective-layer coated Li metal electrodes and LiAg alloy electrodes against bare Li metal electrodes within Li metal batteries(LmBs).Our investigation explores the effects of sample burrs,alignment with the magnetic field,the existence of liquid electrolytes,and precycling on the ^(7)Li NmR *** contrasting NmR spectra before and after cycling,we identi-fied alterations in Li^(0) and Li^(+) signals attributable to the degradation of the Li metal *** NmR analyses decisively demonstrate the efficacy of the protective layer in mitigating dendrite and solid elec-trolyte interphase ***,we noted that Li*ions near the Li metal surface exhibit magnetic susceptibility anisotropy,revealing a novel approach to studying diamagnetic species on Li metal elec-trodes in *** study provides valuable insights and practical guidelines for characterizing distinct lithium states within LmBs.

关键词： NmR spectroscopy Lithium-7 Lithium metal battery Electrolyte Electrode-protective layer Solid electrolyte interface magnetic susceptibility anisotropy Lithium-metal NmR signal Diamagnetic^(7)Li NmR signal