检索结果-南通市图书馆

A fast numerical method of introducing the strengthening effect of residual stress and strain to tensile behavior of metal matrix composites

在线全文

学校读者我要写书评

暂无评论

journal of Materials science & Technology 2021年第28期87卷 167-175页

作者： j.F.zhang X.X.zhang H.Andrä Q.z.Wang B.l.Xiao z.Y.Ma shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China University of Chinese Academy of sciences Beijing 100049China Fraunhofer Institute for Industrial Mathematics Fraunhofer-Platz 1Kaiserslautern 67663Germany

Thermal residual stress and strain(TRss)in particle reinforced metal matrix composites(PRMMCs)are believed to cause strengthening effects,according to previous ***,the representative volume element(RVE)based computational homogenization technique was used to study the tensile deformation of PRMMCs with different particle aspect ratios(AR).The influence of TRss was assessed quantitatively via comparing simulations with or without the cooling *** was found that the strengthening effect of TRss was affected by the particle *** the average strengthening effect of TRss,a fast method of introducing the strengthening effect of TRss to the tensile behavior of PRMMCs was *** new method has reduced the computational cost by a factor *** effect of TRss on continuous fiber-reinforced metal matrix composite was found to have a softening-effect during the entire tensile deformation process because of the pre-yield effect caused by the cooling process.

关键词： Metal matrix composites(MMC) Finite element analysis(FEA) Representative volume element(RVE) Residual stress and strain Aspect ratio

Influencing mechanism of pre-existing nanoscale Al5Fe2 phase on Mg-Fe interface in friction stir spot welded Al-free zK60-Q235 joint

在线全文

学校读者我要写书评

暂无评论

journal of Materials science & Technology 2020年第7期42卷 220-228页

作者： R.z.Xu Q.Yang D.R.Ni B.l.Xiao C.z.liu z.Y.Ma Institute of Metal Research Chinese Academy of SciencesShenyang110016China College of Material science and Engineering Shenyang Aerospace UniversityShenyang110136China Department of Materials science and Engineering University of Illinois at Urbana-Champaign1304 W Green StUrbanaIL61801United States Fredrick seitz Materials Research laboratory University of Illinois at Urbana-Champaign104 S Goodwin AveUrbanaIL61801United States

Al-free zK60 magnesium (Mg) alloy sheet was selected as substrate material of Mg-steel pinless friction stir spot welding (FssW), avoiding the effect of the Al element in the substrate on the alloying reaction of Mg-iron (Fe) interface. The sound FssW joint of zK60 Mg alloy and Q235 steel with a hot-dipped aluminum (Al)-containing zinc (zn) coating was successfully real.zed. The detailed microstructural examinations proved that Al5Fe2 phase at the Mg-Fe interface came from the pre-existing Al5Fe2 phase in the coating and acted as the transition layer for promoting the metallurgical bonding of Mg and Fe. The interfaces with well-matched lattice sites among Fe, Al5Fe2 and Mg were formed during FssW. A low energy interface with good match of lattice sites ((002)Al5Fe2//(110)Fe, [110]Al5Fe2//[113]Fe) between Al5Fe2 and Fe was identified. For the interface between Al5Fe2 and Mg, an orientation relationship of (622)Al5Fe2//(3112)Mgand[158]Al5Fe2//[2423]Mg was observed. The tensile-shear load of the zK60-steel joint could reach 4.6 kN. Moreover, the joint fracture occurred at the interface between the Al5Fe2 layer and the Mg alloy substrate, suggesting the brittle fracture characteristic.

关键词： Dissimilar welding Friction stir spot welding Magnesium alloys steels zinc coating

Identification of Orientia tsutsugamushi,spotted fever group and typhus group Rickettsia by duplex and nested PCR methods

在线全文

学校读者我要写书评

暂无评论

Asian Pacific journal of Tropical Medicine 2008年第4期1卷 1-8页

作者： M-C luan D-z Yu l Tang l-j zhang Department of Rickettsiology National Institute of Communicable Disease Control and PreventionChina CDC Department of Microorganism Dalian Center for Disease Control and Prevention Department of Microecology Dalian medical university Department of Rickettsiology National Institute of Communicable Disease Control and PreventionChina.CDC

Objective:To identify members of genera of rickettsia and *** ***:Rapid and duplex and nested PCR methods have been established by designing primers based on the conserved regions of heat shock protein GroEl gene.345 mouse viscera samples including liver,spleen and kidney,96 Xenopsylla cheopis and 32 chiggers collected from Hongta areas of Yuxi city,Yunnan province were tested by the new PCR ***:The result of the study showed that the new PCR methods could identify most members of genera -Rickettsia and Orientia simultaneously with 100%specificity and its sensitivity could test one copy per *** results of detection prevalence of rickettsioses in mouse,flea and mites DNA samples showed that the total rickettsia infection rate in mouse was 34.78%(120/345).The total infection rates in ***,O.t Karp and *** of mouse samples were 28.12%(97/345),19.71%(68/345) and O. 29%(1/345) ***-infection rates in *** and 0.t Karp of mouse samples were 13.33%(46/ 345).O.t Karp type has been the main epidemic strain in these ***:We concluded that this PCR method could be used to detect multi-genera rickettsia *** evidences provided in this and previous studies strongly support that Hongta areas of Yuxi city are a natural focus for typhus and scrub typhus with the common occurrence of their confection.

关键词： Rickettsia,GroEl gene Duplex and nested PCR

sTREss ANAlYsIs OF THE APERTURE IN COMPOUND PIPElINE BY FEM

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English letters) 2007年第5期20卷 385-390页

作者： j.G. Yang H.Y. Fang C.l. Fan z. luo X.z. Hou state Key laboratory of Advanced Welding Production Technology Harbin Institute of Technology Harbin 150001 China school of Material science and Engineering Tianjin University Tianjin 300072 China Daqing Oil-Ghem-Wdding Institute Daqing 163712 China

There is a cyclical aperture at a certain part of the fiberglass reinforced plastic compound pipeline with a stainless steel pipe as a liner, which becomes the weakness of the conduit. The field of stress and strain of the aperture was investigated using the nonliner finite element code Marc. The results of the finite element analysis showed that there were concentrations of stress and strain in the layer of stainless steel at the part of the pipeline where the aperture existed. The method to solve these problems was also discussed.

关键词： compound pipeline stress software Marc

Microstructural Evolution and Mechanical Properties of laminated CuAl Composites Processed by Accumulative Roll-Bonding and Annealing

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English letters) 2021年第7期34卷 925-931页

作者： H.R.lin Y.z.Tian s.j.sun z.F.zhang shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China school of Materials science and Engineering University of Science and Technology of ChinaHefei 230026China Key laboratory for Anisotropy and Texture of Materials(Ministry of Education) School of Materials Science and EngineeringNortheastern UniversityShenyang 110819China Research Center for Metallic Wires Northeastern UniversityShenyang 110819China

Nano structured Cu-/Al-laminated composites were processed by accumulative roll-bonding(ARB)technique for four *** evolutions inside the Cu and Al layers and the interfacial reactions were revealed after annealing at different *** and recrystall.zation occurred in the Cu and Al layers at low annealing temperatures,and three kinds of intermetallic compounds formed near the *** mechanical properties of these composites after annealing were investigated by tensile tests,and the variation of strength-ductility synergy was comprehensively discussed by considering the roles of constituent and the intermetallic compounds.

关键词： CuAl composites Accumulative roll-bonding(ARB) Annealing Intermetallic compounds Ductility

Designing metallic glasses with optimal combinations of glass-forming ability and mechanical properties

在线全文

学校读者我要写书评

暂无评论

journal of Materials science & Technology 2021年第8期67卷 254-264页

作者： s.j.Wu z.Q.liu R.T.Qu z.F.zhang laboratory of Fatigue and Fracture for Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China school of Materials science and Engineering University of Science and Technology of ChinaHefei 230026China

It is a long-standing challenge to search for metallic glasses(MGs)with optimal combinations of glassforming ability(GFA),strength and toughness in the vast compositional *** taking into account both recently developed ellipse criterion and temperature-based GFA criterion,here we established quantitative correlations among compositions,elastic constants,GFA and mechanical properties of MGs,which enable to predict the GFA,fracture strength and fracture surface simultaneously in advance once the compositions of MGs are *** data confirm the validity of this approach in ***,a strategy for designing MGs with optimal combinations of strength,toughness and GFA is proposed,which allows for high-throughput discovering glass formers with excellent mechanical properties.

关键词： Metallic glass Composition Elastic constant Mechanical property Glass-forming ability

GROWTH PROCEss OF lOW-TEMPERATURE PlAsMA-NITRIDING lAYER ON AUsTENITIC sTAINlEss sTEEl

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English letters) 2004年第2期17卷 210-214页

作者： z.W.Yu l.Wang X.l.Xu j.B.Qiang DalianMaritimeUniversity Dalian116026China DalianUniversityofTechnology Dalian116026China

The growth process of low-temperaturs plasma-nitriding layer was investigated by scan-ning electron microscopy (sEM) and X-ray diffraction (XRD). The layer is composedof expanded fcc phase (γN), whose lattice parameter of the layer increases with processtime resulting from increasing the nitrogen content. The layer hardness increases grad-ually with nitrogen content. The high slip band density on the layer surface observedin situ by sEM shows that the surface yield occurs when supersaturated nitrogen con-tent in the layer attains to some value, which is also responsible for the increase inlayer hardness.

关键词： austenitic stainless steel plasma nitriding slip band

DIFFERENTIAl sCANNING CAlORIMETRY AND X-RAY DIFFRACTION sTUDIEs ON AGING BEHAVIOR OF zn-Al AllOYs

在线全文

学校读者我要写书评

暂无评论

Acta Metallurgica sinica(English letters) 2001年第2期14卷 109-114页

作者： X.l. Xu, z. W. Yu, s.j. ji, j.C. sun and z.K. Hei (Dalian Maritime University, Dalian 116024, China) Dalian Maritime University

Decomposition processes of the quenched zn-Al alloys were studied by differential scanning calorimetry (DsC), X-ray diffraction (XRD) and transmission electron microscopy (TEM). The results show that the stabilities of supersaturated solid solution (sss) of zn-Al alloy and α' phase formed by quenching would reduce with the increase of zn content and the precipitation of η-zn phases even when aging at ambient temperature, so that the exothermic precipitation peak in DsC curve would disappear. The activation energy of the η-zn precipitation and the reaction enthalpy were calculated and measured. The kinetics of α' decomposition or η-zn formation was determined by XRD. The microstructure change during aging was observed by TEM.

关键词： Aging of materials Aluminum alloys Differential scanning calorimetry X ray diffraction

large ferro-pyro-phototronic effect in 0.5Ba(zr_(0.2)Ti_(0.8))O_(3)-0.5(Ba_(0.7)Ca_(0.3))TiO_(3)thin films integrated on silicon for photodetection

在线全文

学校读者我要写书评

暂无评论

Carbon Energy 2023年第6期5卷 1-10页

作者： j.séP.B.silva Katarzyna Gwozdz luís s.Marques Mario Pereira Maria j.M.Gomes judith l.MacManus‐Driscoll Robert l.z.Hoye Centre of Physics of Universities of Minho and Porto(CF‐UM‐UP) University of MinhoBragaPortugal laboratory of Physics for Materials and Emergent Technologies LapMETUniversity of MinhoBragaPortugal Department of Quantum Technologies Faculty of Fundamental Problems of TechnologyWroclaw University of Science and TechnologyWroclawPoland Department of Materials science and Metallurgy CambridgeUK Inorganic Chemistry laboratory Department of ChemistryUniversity of OxfordOxfordUK Department of Materials Imperial College LondonLondonUK

Coupling together the ferroelectric,pyroelectric,and photovoltaic characteristics within a single material is a novel way to improve the performance of *** this work,we take advantage of the triple multifunctionality shown by 0.5Ba(zr_(0.2)Ti_(0.8))O_(3)-0.5(Ba_(0.7)Ca_(0.3))TiO_(3)(BCzT),as demonstrated in an Al/si/siOx/BCzT/ITO thin-film *** si/siOx acts as an n-type layer to form a metal-ferroelectric-insulator-semiconductor heterostructure with the BCzT,and with Al and ITO as *** photo-response of the device,with excitation from a violet laser(405 nm wavelength),is carefully investigated,and it is shown that the photodetector performance is invariant with the chopper frequency owing to the pyro-phototronic effect,which corresponds to the coupling together of the pyroelectric and photovoltaic ***,the photodetector performance was significantly better than that of the devices operating based only on the pyro-phototronic effect by a factor of 4,due to the presence of ferroelectricity in the ***,after a poling voltage of−15 V,for a laser power density of 230mW/cm^(2)and at a chopper frequency of 400Hz,optimized responsivity,detectivity,and sensitivity values of 13.1mA/W,1.7×10^(10)jones,and 26.9,respectively,are ***,ultrafast rise and fall times of 2.4 and 1.5μs,respectively,are obtained,which are 35,000 and 36,000 times faster rise and fall responses,respectively,than previous reports of devices with the ferro-pyro-phototronic *** is understood based on the much faster ferroelectric switching in ferroelectric thin films owing to the predominant 180°domains in a single direction out of plane.

关键词： ferroelectric ferro-pyro-phototronic effect photodetector polarization-controlled response