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The hot compressive deformation behavior of cast mg-Gd-Y-Zn-Zr alloys with and without LPSO phase in their initial microstructures

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Journal of magnesium and Alloys 2022年第10期10卷 2901-2917页

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

Samples of mg-8.2Gd-3.8Y-1.1Zn-0.4Zr alloy with and without an intragranular lamellae-shaped long period stacking ordered(LPSO)phase were prepared through heat treatment and a series of hot compression tests on these materials were conducted to examine and evaluate the influence of LPSO on the hot compressive deformation behavior and deformation mechanisms at a given alloy *** values of activation energy for plastic flow(Qc)of the solution treated(without LPSO phase)and annealed alloys(with intragranular LPSO phase)were larger than that for pure mg,indicating that the presence of a high amount of rare earth(RE)elements and LPSO in the mg matrix significantly increases *** Qcvalue of the annealed alloy was larger than that of the solution treated alloy at all the strain levels(223.3 vs.195.5 k J/mol in average)and the largest difference in Qcbetween the two alloys was recorded at the smallest strain of 0.1 where precipitation of LPSO during deformation was limited in the solution treated *** observations imply that the formation of LPSO phase out of the RE-rich solid solution matrix during deformation increases Qc,but the increment is not so *** of the hot compressive data of the alloys with LPSO phase and the alloys with RE-rich solid solution matrix in literatures indicates the similarity of the effect of the LPSO and RE-rich solid solution matrix phases on Qcand high-temperature strength.

关键词： magnesium alloys LPSO Deformation mechanism Dynamic recrystallization Activation energy for plastic flow Processing maps

mixing features in an electromagnetic rectangular micromixer for electrolyte solutions

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Journal of hydrodynamics 2017年第4期29卷 668-678页

作者： m.m.Wen C.N.kim Department of mechanical Engineering Graduate School Kyung Hee University Department of mechanical Engineering College of Engineering Kyung Hee University

In this study, a new magnetohydrodynamic（mhD） mixer for electrolyte solutions with pumping function is reported, and the mixing performance of the device for two different electrolyte solutions is numerically examined in a uniform magnetic field. Application of different potentials to different electrodes allows the current to be induced. The combination of the induced current and magnetic field yields Lorentz force, resulting in the fluid motion. The numerical simulation for the flows in the device is carried out with commercial software CFX. The validity of CFX code for the present numerical model is presented. The mixing performance of the fluids is investigated in many different cases with different combinations of input voltage of the electrode. This study shows that the mixing performance can be enhanced by applying spatially alternating positive and negative voltages to the electrodes. The present simulation results show that with a magnetic field intensity lower than 0.5 T, a voltage difference smaller than 2.0 V, and an electric conductivity of electrolyte solution of 1.5 S/m the pumping capabilities ranging 1.6×10^（-7）-3.6×10^（-6） kg/s and the mixing indexes higher than 0.90 can be obtained with sophisticated designs of the micromixer.

关键词： mixer electrolyte solution Lorentz force CFX

Critical review of superplastic magnesium alloys with emphasis on tensile elongation behavior and deformation mechanisms

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Journal of magnesium and Alloys 2022年第5期10卷 1133-1153页

作者： h.T.Jeong W.J.kim Department of materials Science and Engineering Hongik UniversitySangsu-dong 72-1 Mapo-guSeoul 121-791South Korea

The tensile elongation behavior and deformation mechanisms of superplastic mg alloys and mg composites were examined by extensively reviewing the literature published from the time of the first report on the superplasticity of mg alloys to the present *** on the superplasticity of mg alloys have been conducted mainly on mg-Al-Zn(AZ)series alloys,mg-Zn-Zr(ZK),mg-Li and mg-RE(rare earth)alloys,and in recent years,mg-RE alloys have attracted the greatest *** effect of grain size and the type and amount of secondary phase particles on the superplasticity of mg alloys was systematically examined and *** alloys processed by severe plastic deformation(SPD)and powder-metallurgy methods have smaller grain sizes and exhibit superior superplasticity compared to conventionally processed(by extrusion and rolling)mg *** the AZ alloys,as the volume fraction of the mg17Al12phase increases,smaller grains are obtained,and the low-temperature superplasticity(LTS)and high-strain-rate superplasticity(hSRS)characteristics become *** ZK60 alloy with finely dispersed mg Zn2particles exhibits excellent LTS,while the mg-RE alloys with a high fraction of thermally stable particles exhibit excellent ***-Li alloys can exhibit LTS even at room temperature due to the presence of a high-volume fraction of the body centered cubic(BCC)phase where atomic diffusivity is *** boundary diffusion-and lattice diffusion-controlled grain boundary sliding are found to operate as the dominant deformation mechanisms below~473 K and above~673 K,respectively,at small grain *** mechanism maps were constructed based on the analysis of the deformation behavior of superplastic mg alloys,and from the maps,the critical conditions for achieving LTS,hSRS and simultaneous achievement of LTS and hRSR were calculated and proposed,and their importance was discussed.

关键词： magnesium alloys Superplastic Grain size Secondary phase Grain boundary sliding

Properties of Dispersion Casting of Y2O3 Particles in hypo,hyper and Eutectic Binary Al-Cu Alloys

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Journal of materials Science & Technology 2008年第1期24卷 57-59页

作者： J.J.Park G.h.kim S.m.hong S.h.Lee m.K.Lee C.K.Rhee Nuclear Nano-materials Development Lab. Korea Atomic Energy Research Institute （KAERI） 150 Deukjin-dongYuseong-gu Daejeon Korea

In the present work,the dispersion casting of Y-2O-3 particles in aluminum-copper alloy was investigated in terms of microstructural changes with respect to Cu contents of 20 （hypo）,33 （eutectic） and 40 （hyper） wt pct by scanning electron microscopy （SEm） and energy dispersive spectroscopy （EDS）.For the fabrication of Al-Cu alloy dispersed Y-2O-3 ceramic particles,stir casting method was *** case of Al-20 wt pct Cu alloy （hypoeutectic）,SEm images revealed that primary Al was grown up in the *** that,eutectic phase with well dispersed ceramic particles was *** case of eutectic composition,Y-2O-3 particles were uniformly dispersed in the *** the Cu is added into Al up to 40 wt pct （hypereutectic）,primary phase was grown up without any Y-2O-3 ceramic particles in the early stage of ***, eutectic phase was formed with well dispersed ceramic *** can be concluded that Y-2O-3 ceramic particles is mostly dispersed in case of eutectic composition in Al-Cu alloy.

关键词： Dispersion casting Y2O3 particles Stir casting Al-Cu alloy

Effect of Solute Contents of Al-Ni-Sr Alloy on Glass Forming Ability and Thermal Stability

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Journal of Rare Earths 2004年第z2期22卷 73-77页

作者： Taek Soo kim J K Lee h J kim J C Bae Advanced materials R&D Center Korea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea Advanced Materials R&D CenterKorea Institute of Industrial Technology994-32 Dongchun-dongYeonsu-kuIncheon 406-130Korea

Glass forming ability (GFA) and structural characterization of a new amorphous Al-Ni-Sr alloy melt spun were investigated on the theory of the factors for the glass formation. The GFA was varied with the ratio of Ni to Sr in detail and successful amorphous phase dispersed with 2 ～ 5 nm precipitates was prepared from Al-Ni5-Sr3. Thermal stability and crystallization behavior of the amorphous phase were determined by continuous and isothermal heating technique on DCS, resulting that the crystallization occurs by the growth of fcc Al nanocrystals on the preexistent nuclei.

关键词： glass formation crystallization Al base amorphous alloys rapid solidification

Implementation of a double trigger condition system based on charge comparison and TOF measurement for the NEDA detector array

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Nuclear Science and Techniques 2025年第2期36卷 40-48页

作者： J.m.Deltoro A.Goasduff F.J.Egea V.González A.Gadea R.m.Pérez-Vidal I.Lazarus m.Kogimtzis L.mcNicholl m.Palacz G.Jaworski J.J.Valiente-Dobón J.Nyberg S.Casans A.E.Navarro-Antón E.Sanchis A.Boujrad E.Clément T.hüyük R.Illicachi O.Stezowski V.modamio Department of Electronic Engineering University of ValenciaBurjassotValenciaSpain Istituto Nazionale di Fisica Nucleare Laboratori Nazionali di LegnaroLaboratori Nazionali di LegnaroLegnaroPadovaItaly Instituto de Física Corpuscular CSIC-Universidad de ValenciaCSIC-Universidad de Valencia46980 PaternaValenciaSpain Science and Technology Facilities Council DaresburyUK heavy Ion Laboratory University of Warsaw02-093 WarsawPoland Department of Physics and Astronomy Uppsala UniversityUppsalaSweden Grand Accélérateur National d’Ions Lourds(GANIL) CEA/DRF-CNRS/IN2P3CEA/DRF-CNRS/IN2P3CaenFrance Universitéde Lyon UniversitéLyon-1CNRS/IN2P3UMR5822IP2IIP2I4 Rue Enrico Fermi69622 Villeurbanne CedexFrance Department of Physics University of Oslo0316 OsloNorway

The NEutron Detector Array(NEDA)is designed to be coupled to gamma-ray spectrometers to enhance the sensitivity of the setup by enabling reaction channel selection through counting of the evaporated *** article presents the implementation of a double trigger condition system for NEDA,which improves the acquisition of neutrons and reduces the number of gamma rays *** independent triggers are generated in the double trigger condition system:one based on charge comparison(CC)and the other on time-of-flight(TOF).These triggers can be combined using OR and AND logic,offering four distinct trigger *** developed firmware is added to the previous one in the Virtex 6 field programmable gate array(FPGA)present in the system,which also includes signal processing,baseline correction,and various trigger logic *** performance of the trigger system is evaluated using data from the E703 experiment performed at *** four trigger modes are applied to the same data,and a subsequent offline analysis is *** is shown that most of the detected neutrons are preserved with the AND mode,and the total number of gamma rays is significantly *** with the CC trigger mode,the OR trigger mode allows increasing the selection of *** addition,it is demonstrated that if the OR mode is selected,the online CC trigger threshold can be raised without losing neutrons.

关键词： Neutron detector Neutron-gamma discrimination Pulse shape analysis Time-of-flight Charge comparison

Compound heterozygous mutation of AFG3L2 causes autosomal recessive spinocerebellar ataxia through mitochondrial impairment and mICU1 mediated Ca2+overload

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Science China(Life Sciences) 2025年第2期68卷 484-501页

作者： hongyu Li Qingwen ma Yan Xue Linlin Cai Liwen Bao Lei hong Yitao Zeng Shu-Zhen huang Richard h.Finnell Fanyi Zeng Shanghai Institute of medical Genetics Shanghai Children’s HospitalShanghai Jiao Tong University School of MedicineShanghai 200040China Department of histo-Embryology Genetics and Developmental BiologyShanghai Jiao Tong University School of MedicineShanghai 200025China NhC Key Laboratory of medical Embryogenesis and Developmental molecular Biology Shanghai Key Laboratory of Embryo and Reproduction EngineeringShanghai 200040China Center for Precision Environmental health Baylor College of MedicineHouston 77030USA School of Pharmacy Macao University of Science and TechnologyMacao 999078China

Autosomal recessive spinocerebellar ataxias(SCARs)are one of the most common neurodegenerative diseases characterized by progressive *** SCARs are known to be caused by mutations in multiple genes,there are still many cases that go undiagnosed or are *** this study,we presented a SCAR patient,and identified a probable novel pathogenic mutation(c.1A>G,p.m1V)in the AFG3L2 start *** proband's genotype included heterozygous mutations of the compound AFG3L2(p.[m1V];[R632X](c.[1A>G];[1894.C>T])),which were inherited from the father(c.1A>G,p.m1V)and mother(c.1894C>T,p.R632X).Functional studies performed on hi PSCs(human induced pluripotent stem cells)generated from the patients and hEK293T cells showed that the mutations impair mitochondrial function and the unbalanced expression of AFG3L2 mRNA and protein ***,this novel mutation resulted in the degradation of the protein and the reduction of the stability of the AFG3L2 protein,and mCU(mitochondrial calcium uniporter)complex mediated Ca2+overload.

关键词： AFG3L2 gene autosomal recessive spinocerebellar ataxia mitochondrial impairment Ca2+overload

Vertically aligned NiS nano-flakes derived from hydrothermally prepared Ni(Oh)2 for high performance supercapacitor

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Journal of Energy Chemistry 2018年第3期27卷 791-800页

作者： A.m.Patil A.C.Lokhande P.A.Shinde J.h.kim C.D.Lokhande Thin Film Physics Laboratory Department of PhysicsSbivaji UniversityKolbapar 416004 MHIndia Department of materials Science and Engineering Chonnam National University 300 Yongbong-DongPuk-GuGwangju.South Korea Centre for Interdisciplinaly Research D.Y.Patil UniversityKolhapurIndia

In present work,the vertically aligned Ni S nano-flakes composed thin film is prepared by anionic exchange process in which hydrothermally prepared Ni（Oh）2is used as a parent thin film and Na2S as a sulfide ion *** synthesis process produced fully transformed and shape-controlled nano-flakes of Ni S from nano-flowers of Ni（Oh）*** electrochemical supercapacitor properties of Ni S electrode are studied with cyclic voltammetry（CV）,galvonostatic charge discharge（GCD）and electrochemical impedance spectroscopy（EIS）*** porous surface area（85 m^2/g）of Ni S nano-flakes makes large material contribution in electrochemical reaction stretching specific capacitance（Cs）of 880 F/g at scan rate of 5 m V/s and 90%electrochemical stability up to 4000 CV cycles in 2 m KOh ***,the flexible solid-state symmetric supercapacitor device（Ni S/PVA–Li ClO4/Ni S）has been fabricated using Ni S electrodes with polyvinyl alcohol（PVA）–lithium perchlorate（Li ClO4）gel *** Ni S/PVA–Li ClO4/Ni S device exhibits specific capacitance of 56 F/g with specific energy of 14.98 Wh/kg and excellent cycling stability after 2000 *** addition,the Ni S/PVA–Li ClO4/Ni S device demonstrates illumination of red light emitting diode（LED）for 60 s,which confirms the practical applicability of Ni S/PVA–Li ClO4/Ni S device in energy storage.

关键词： Anionic exchange process Nickel sulfide Nano-flakes Supercapacitor Thin film

The Effect of Reflector with Sound-Absorbing material on Supersonic Jet Noise

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Journal of Thermal Science 2005年第1期14卷 22-27页

作者： Y.-h.KWEON m.TSUChIDA Y.mIYAZATO T.AOKI h.-D.kim T.SETOGUChI Department of Energy and Environmental Engineering Kyushu University Kasuga 816-8580Japan School of mechanical Engineering Andong National University Andong 760-749Korea Department of mechanical Engineering Saga University Saga 840-8502Japan

This paper describes an experimental work to investigate the effect of a reflector on supersonic jet noise radiated from a convergent-divergent nozzle with a design mach number *** the present study,a metal reflector and reflectors made of three different sound-absorbing materials(grass wool and polyurethane foam)were employed,and the reflector size was *** measurement is carried out to obtain the acoustic characteristics such as frequency,amplitude of screech tone and overall sound pressure level(OASPL).A high-quality schlieren optical system is used to visualize the detailed structure of supersonic *** results obtained show that the acoustic characteristics of supersonic jet noise are strongly dependent upon the jet pressure ratio and the reflector *** is also found that the reflector with sound-absorbing material reduces the screech tone amplitude by about 5-13dB and the overall sound pressure levels by about 2-5dB,compared with those of the metal reflector.

关键词： supersonic jet supersonic jet noise screech tone OASPL reflector sound-absorbing material.