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Tailoring precipitation/properties and related mechanisms for a high-strength aluminum alloy plate via low-temperature retrogression and re-aging processes

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Journal of Materials Science & Technology 2022年第25期120卷 15-35页

作者： l.G.Hou H.Yu Y.w.wang l.You Z.B.He C.M.wu d.G.Eskin l.Katgerman l.Z.Zhuang J.S.Zhang State Key laboratory for Advanced Metals&Materials University of Science&Technology BeijingBeijing 100083China BCAST Brunel University LondonKingston LaneUxbidge Middlesex UB83PHUnited Kingdom Institute of mineral resources Chinese Academy of Geological SciencesBeijing 100037China Nanjing Advanced Transportation Equipment New Technology Research Institute Nanjing 211800China Tomsk State University Tomsk634050Russian Federation Katgerman Aluminium Technology van Beuningenlaan 102334CC LeidenNetherlands department of Materials Science and Engineering Delft University of TechnologyMekelweg 22628CD Delftthe Netherlands

The retrogression and re-aging(RRA)processes,aimed mainly at tailoring intergranular precipitates,could significantly improve the corrosion resistance(i.e.,stress corrosion cracking resistance)without considerably decreasing the strength,which signifies that an efficient control of the size,distribution and evolution of intergranular and intragranular precipitates becomes critical for the integrated properties of the(mid-)thick high-strength Al alloy *** to RRA process with retrogression at200℃ (T77),this study investigated the impact of a modified RRA process(MT77)with lower retrogression temperatures(155-175℃ )and first-stage under-aging on the properties of a high-strength AA7050 Al alloy,in combination with detailed precipitate *** study showed that the strength/microhardness of the RRA-treated alloys decreased with raising retrogression temperature and/or prolonging retrogression time,along with the increased electrical *** rapid responsiveness of microstructure/property typical of retrogression at 200℃ was obviously postponed or decreased by using MT77 process with longer retrogression time that was more suitable for treating the(mid-)thick *** the other hand,higher retrogression temperature facilitated more intragranularηprecipitates,coarse intergranular precipitates and wide precipitate free zones,which prominently increased the electrical conductivity alongside a considerable strength loss as compared to the MT77-treated *** the preferred MT77 process,the high strength approaching T6 level as well as good corrosion resistance was ***,though a relatively homogeneous through-thickness strength was obtained,some small discrepancies of properties between the central and surface areas of an 86-mm thick 7050 Al alloy plate were observed,possibly related to the quenching *** precipitate evolution and mechanistic connection to the properties were discussed and reviewed for high-strengt

关键词： Aluminum alloy Heat treatment Precipitation Strength Grain boundary

Uprooting phylogenetic uncertainty in coalescent species delimitation： A meta-analysis of empirical studies

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Current Zoology 2015年第5期61卷 866-873页

作者： Itzue w. C AVIEdES-SOlIS Nassima M. BOUZId Barbara l. BANBURY Adam d. lEACHE department of Biology University of Washington Seattle WA 98195 USA Burke Museum of Natural History and Culture University of Washington Seattle WA 98195 USA

Phylogenetic and phylogeographic studies rely on the accurate quantification of biodiversity. In recent studies of taxonomically ambiguous groups, species boundaries are often determined based on multi-locus sequence data. Bayesian Phylogenetics and Phylogeography （BPP） is a coalescent-based method frequently used to delimit species; however, empirical studies suggest that the requirement of a user-specified guide tree biases the range of possible outcomes. we evaluate fifteen multi-locus datasets using the most recent iteration of BPP, which eliminates the need for a user-specified guide tree and reconstructs the species tree in synchrony with species delimitation （= unguided species delimitation）. we found that the number of species recovered with guided versus unguided species delimitation was the same except for two cases, and that posterior probabilities were generally lower for the unguided analyses as a result of searching across species trees in addition to species delimitation models. The guide trees used in previous studies were often discordant with the species tree topologies estimated by BPP. we also compared species trees estimated using BPP and ＊BEAST and found that when the topologies are the same, BPP tends to give higher posterior probabilities [Current Zoology 61 （5）： 866-873, 2015].

关键词： BPP Species delimitation Phylogeography Species tree

Mapping QTl associated with Verticillium dahliae resistance in the cultivated strawberry(Fragaria×ananassa)

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Horticulture Research 2015年第1期2卷 272-279页

作者： l Antanaviciute NŠurbanovski N Harrison K J Mcleary d w Simpson F wilson d J Sargent R J Harrison East Malling Research New RoadEast MallingKent ME196BJUK Research and Innovation Centre Fondazione Edmund MachVia E.Mach 138010 San Michele all’Adige(TN)Italy

A biparental cross of octoploid strawberry segregating for resistance to Verticillium dahliae,the causative agent of Verticillium wilt,was screened under field conditions for three *** wilt scores were significantly associated with multiple QTl,which were mostly significant across all *** significantly associated with the traits were used to screen material with known wilt resistance and susceptibility phenotypes.A clear and statistically significant relationship was observed between resistant,tolerant and susceptible material and the total number of markers present in the different resistance *** field situations resistance QTl appear to behave in an additive *** markers are abundant in the cultivated strawberry germplasm indicating that,despite the large number of markers,clear genetic gain is possible through marker-assisted breeding.

关键词： straw Fragaria resistance

Ultrasonic excitation induced nanocrystallization and toughening of Zr46.75Cu46.75Al6.5 bulk metallic glass

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Journal of Materials Science & Technology 2020年第10期42卷 157-161页

作者： w.Zhai l.H.Nie X.d.Hui Y.Xiao T.wang B.wei School of Physical Science and Technology Northwestern Polytechnical UniversityXi'an 710072China State Key laboratory for Advanced Metals and Materials University of Science&Technology BeijingBeijing 100083China

Intensive power ultrasound is introduced to Zr46.75Cu46.75Al6.5bulk metallic glass(BMG)as an easy-procurable,non-destructive physical method to modulate its atomic rearrangement and shear deformation *** microstructure after ultrasonic excitation with amplitude about 15μm in 20 k Hz for 2 h is characterized by large amount of Cu10Zr7 nanocrystals with size of 20–50 nm embedded in the glass *** leads to a sharp increase in the critical stress for the first pop-in event of shear banding,and thus simultaneously improves both compressive plasticity and yield *** findings provide a novel approach for overcoming the strength-ductility trade-off dilemma.

关键词： Bulk metallic glass Nanocrystallization Plasticity Toughness Ultrasound

Surface diffusivity of atomic deuterium on Ni_3(Al, Ti)(110) surface with and without boron

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中国有色金属学会会刊：英文版 2002年第4期12卷 649-652页

作者： J.l.wang Y.w.Chung departmentofMaterialsScienceandEngineering RobertR.McCormickSchoolofEngineeringandAppliedScienceNorthwesternUniversityEvanstonIL60208USA departmentofMaterialsScienceandEngineering RobertR.McCormic

The electron stimulated desorption was used to measure the surface diffusivity of atomic deuterium on clean and boron modified Ni 3(Al, Ti)(110) surfaces. Boron dosing was performed using a solid state boron ion source. Earlier studies showed that boron dissociates water readily at temperatures as low as 130?K and that the resulting atomic hydrogen is bound to the surface strongly. The surface diffusion coefficient of atomic d on 0.05 monolayer boron modified surface was measured to be about 10 times smaller than that on the clean surface. This slower diffusion of atomic hydrogen may explain why boron improves the ductility of polycrystalline Ni 3Al in moist environments.

关键词：氘原子表面扩散硼 Ni3Al Ni3Ti 金属间化合物

OPTICAl CHARACTERIZATION OF TiO_2 THIN FIlM ON SIlICON SUBSTRATE dEPOSITEd BY dC REACTIVE MAGNETRON SPUTTERING

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Acta Metallurgica Sinica(English letters) 2005年第3期18卷 194-198页

作者： H.Q.wang H.Shen d.C.Ba B.w.wang l.S.wen d.Chen SchoolofMechanismandAutomobile ShenyangInstituteofAeronauticalEngineeringShenyang110034Ghina／／MechanismandAeronauticalCollegeNortheasternUniversityShenyang110004China TheSchoolofPhysicsandEngineering ZhongshanUniversityGuangzhou510275Ghina MechanismandAeronauticalCollege NortheasternUniversityShenyang110004China GuangzhouInstimdeofEnergyConversion Guangzhou510070China InstituteofMetalResearch TheChineseAcademyofSciencesShenyang110016China MaterialandScienceEngineeringAcademy SouthChinaUniversityofTechnologyGuangzhou510641China

TiO2 thin film has attracted considerable attention in recent years, due to its different refractive index and transparency with amorphous and different crysta ls in the visible and near-infrared wavelength region, high dielectric constant, wide band gap, high wear resistance and stability, etc, for which make it being used in many fields. This paper aims to investigate the optical characterizatio n of thin film TiO2 on silicon wafer. The TiO2 thin films were prepared by dC re active magnetron sputtering process from Ti target. The reflectivity of the film s was measured by UV-3101PC, and the index of refraction (n) and extinction coef ficient (k) were measured by n & k Analyzer 1200.

关键词： optical characterization TiO2 thin film dC reactive magnetron sputtering n & k

lIGHT PORTABlE ElECTROPNEUMATIC lOUdSPEAKER

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Chinese Journal of Acoustics 1989年第4期8卷 359-365页

作者： MACdONAld d.l. Racal Acoustics ltd.U.K

This paper analyses the influence of certain parameters and factors on the characteristics of the electropneumatic loudspeaker and describes the experimental work carried out. The developed portable electropneumatic loudspeaker possesses good properties with a flat frequency response from 400 Hz to 2 kHz and a maximum sound pressrue output of 120dB at a distance 2 metre on axis from the horn mouth .The magnetic flux density at the magnetic gap is 19 ,000 gauss .The electropneumatic loudspeaker is small in size and lightweight.

关键词： lIGHT PORTABlE ElECTROPNEUMATIC lOUdSPEAKER

NUMERICAl SIMUlATION OF EXTRUSION OF COMPOSITE POwdERS PREPAREd BY HIGH ENERGY MIllING

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Acta Metallurgica Sinica(English letters) 2004年第1期17卷 51-54页

作者： X.Q.li w.P.Chen w.Xia Q.l.Zhu Y.Y.li E.d.wang College of Mechanical Engineering South China University of Technology.Guangzhou 510640 China School of Materials Science and Engineering Harbin Institute of Technology Harbin 150001 China

Based on the characteristic of high energy milling and the micromechanics of composite material, a plastic constitutive equation is implemented for milled composite powders. To check the equation, the extrusion of Ti/Al composite powders prepared by high energy milling was simulated. It was from the numerical analysis that the predicted extrusion pressure mounted up with milling time and extrusion ratio increasing, which was perfect agreement with experimental results.

关键词： high energy milling composite powder plastic constitutive equation extrusion numerical simulation

Stepwise assembly to construct stable copper(I) cluster-based circularly polarized luminescent MOFs

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Science China Chemistry 2025年

作者： Jing-wen Xie Meng-Ting wang Yan Jin Si li Jian-Hua Qin Shuang-Quan Zang Tomas C.w.Mak College of Chemistry Henan Key Laboratory of Crystalline Molecular Functional Materials Zhengzhou University College of Chemistry and Chemical Engineering Luoyang Normal University department of Chemistry The Chinese University of Hong Kong

Circularly polarized luminescence （CPl） materials have been extensively studied in recent years owing to their widespread applications in 3d display,optical storage,optical anti-counterfeiting,and biological imaging,***（I） clusters have emerged as a promising candidate for CPl materials,driven by their cost-effectiveness,superior luminescent properties,precise structure,and low ***,the poor environmental stability of copper（I） clusters renders their synthesis and preservation challenging,thereby significantly impeding their ***,we have designed and synthesised a chiral double-coordinated ligand in order to construct copper（I） cluster nodes that can be further *** anticipated,by utilizing stepwise assembly strategy,a Cu4cluster node co-modified by chiral alkynyl ligands and triphenylphosphine was further assembled with Cd2+ions to obtain 2d layers structure,l/*** l/d-Cu4-Cd exhibits excellent stability and optical properties,including bright yellow emission,solvent-responsive luminescence,and CPl activity with a maximum glumup to 2.0×10-3,which shows potential applications in the wlEd and *** interestingly,the material also exhibits deflection ability towards different wavelengths of linearly polarized light,showing certain potential in the preparation of circular polarizer.

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