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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

Heavy Metals in Brown Rice(Oryza sativa L.) and soil After Long-Term Irrigation of Wastewater Discharged from Domestic sewage Treatment Plants

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Pedosphere 2011年第5期21卷 621-627页

作者： B.Y.chung c.H.sONG B.j.PARk j.Y.cHO Advanced Radiation Technology Institute Korea Atomic Energy Research Institute(KAERI) korea Testing & Research Institute(kTR) Department of Horticultural science Chungbuk National University Department of Bio-environmental chemistry Chonbuk National University

A pot experiment was conducted in a plastic film house to evaluate the translocation and uptake of heavy metals(Pb,cd,cu,and Zn) into brown rice(Oryza sativa L.) and the heavy metals residues in soils which had previously been irrigated with domestic wastewater for a long time(3 years).The range of Pb,cd,cu,and Zn was 5.10 ± 0.01,0.105 ± 0.017,5.76 ± 0.42,and 23.56 ± 1.40 mg kg-1,respectively in the domestic wastewater-irrigated soil,and 0.370 ± 0.006,0.011 ± 0.001,0.340 ± 0.04,and 2.05 ± 0.18 mg kg-1,respectively,in the domestic wastewater-irrigated brown *** results indicated that application of domestic wastewater to arable land slightly increased the levels of Pb,cd,cu,and Zn in soil and brown rice(P concentrations of heavy metals in brown rice were lower than the recommended tolerable levels proposed by the joint FAO/WHO Expert committee on Food ***,the continuous monitoring and pollution control of hazardous materials from domestic wastewater are needed in order to prevent excessive build-up of heavy metals in the food chain.

关键词： accumulation domestic wastewater ground water irrigation P2O5 total N

One-step multi-compositional oxidation of Ysi alloy:Experiments and ab initio computation

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journal of Materials science & Technology 2023年第27期158卷 253-262页

作者： W.j.wang j.c.Luo L.chen G.j.Yang state key Laboratory for Mechanical Behavior of Materials School of Materials Science and EngineeringXi’an Jiaotong UniversityXi’an 710049China Xi’an jiaotong University suzhou Institute Suzhou 215123China

Ysi alloy is a promising candidate as oxidation resistant coatings for both the bond coat of environmental barrier coatings(EBcs)and anti-ablation coatings at a high temperature of∼1300℃.In this study,a one-step multi-compositional oxidation by rapid heating oxidation mode is proposed to reduce the oxidation rate by 3.6 times compared to conventional slow heating oxidation *** show that preferentially formed Y_(2)O_(3) oxide initiates a multi-step oxidation,produces a cracking and porous oxides,and thereby resulting in a fast oxidation with *** one-step multi-compositional oxidation with a compact and dense Y_(2)si_(2)O_(7)scale contributes to the much better oxidation resistance for rapid heating oxidation mode of Ysi *** stable formation of Y_(2)si_(2)O_(7)scale is comprehensively understood by the energy barrier,charge density and electronic level based on density functional *** study demonstrates a promising application of Ysi alloy by rapid heating oxidation mode.

关键词： Ysi alloy One-step oxidation Multi-compositional scale Y_(2)si_(2)O_(7) Energy barrier

Active metal brazing of siO2–BN ceramic and Ti plate with Ag–cu–Ti＋BN composite filler

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journal of Materials science & Technology 2017年第11期33卷 1392-1401页

作者： Z.W.Yang c.L.wang Y.wang L.X.Zhang D.P.wang j.c.Feng Tianjin key Lab of Advanced joining Technology School of Materials Science and Engineering Tianjin University Tianjin 300072 China state key Lab of Advanced Welding andjoining Harbin Institute of Technology Harbin 150001 China

siO2–BN ceramic and Ti plate were joined by active brazing in vacuum with Ag–cu–Ti＋BN composite *** effect of BN content,brazing temperature and time on the microstructure and mechanical properties of the brazed joints was *** results showed that a continuous Ti N–Ti B2reaction layer formed adjacent to the siO2–BN ceramic,whose thickness played a key role in the bonding *** Ti–cu compound layers,Ti2cu,Ti3cu4,Ti cu2and Ti cu4,were observed to border Ti substrate due to the strong affinity of Ti and cu compared with *** central part of the joint was composed of Ag matrix,over which some fine-grains *** added BN particles reacted with Ti in the liquid filler to form fine Ti B whiskers and Ti N particles with low coefficients of thermal expansion（cTE）,leading to the reduction of detrimental residual stress in the joint,and thus improving the joint *** maximum shear strength of 31 MPa was obtained when 3 wt%BN was added in the composite filler,which was 158%higher than that brazed with single Ag–cu–Ti filler *** morphology and thickness of the reaction layer adjacent to the parent materials changed correspondingly with the increase of BN content,brazing temperature and holding *** on the correlation between the microstructural evolution and brazing parameters,the bonding mechanism of siO2–BN and Ti was discussed.

关键词： siO2–BN ceramic BN particles Microstructure Mechanical properties

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

Designing ultrastrong maraging stainless steels with improved uniform plastic strain via controlled precipitation of coherent nanoparticles

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journal of Materials science & Technology 2021年第34期93卷 60-70页

作者： Z.H.wang B.Niu Q.wang c.Dong j.c.jie T.M.wang T.G.Nieh key Laboratory of Materials Modification by Laser Ion and Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Department of Materials science and Engineering The University of TennesseeKnoxville37996TennesseeUSA

The development of ultrastrong maraging stainless steels(Msss)is always in high ***,traditional high-strength Msss generally exhibit early plastic instability with a low uniform strain since the precipitated nanoparticles are non-coherent with the body-centered-cubic(Bcc)lath martensitic ***,we design a novel ultrahigh strength Mss(Fe-5.30 cr-13.47 Ni-3.10 Al-1.22 Mo-0.50 W-0.23 Nb-0.03 c-0.005 B,wt.%)using a cluster formula approach.A fabulous microstructure consisting of a uniform distribution of high-density coherent B2-Ni Al nanoprecipitates(3-5 nm)in Bcc martensitic matrix was successfully *** alloy has not only an exceedingly high ultimate tensile strength of 2.0 GPa,but also a decent uniform elongation of 4.2%-5.1%,which is almost triple of the value observed in existing *** present an in-depth discussion on the origins of ultrahigh strength and uniform plastic strain in the new alloy to validate our design strategy and further offer a new pathway to exploit highperformance Msss.

关键词： Maraging stainless steel Ultrahigh strength coherent precipitation strengthening mechanisms Uniform deformation

Development of Lattice Boltzmann Flux solver for simulation of Incompressible Flows

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Advances in Applied Mathematics and Mechanics 2014年第4期6卷 436-460页

作者： c.shu Y.wang c.j.Teo j.Wu Department of Mechanical Engineering National University of Singapore10 Kent Ridge CrescentSingapore 119260 Department of Aerodynamics College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjing 210016China

A lattice Boltzmann flux solver(LBFs)is presented in this work for simulation of incompressible viscous and inviscid *** new solver is based on chapman-Enskog expansion analysis,which is the bridge to link Navier-stokes(N-s)equations and lattice Boltzmann equation(LBE).The macroscopic differential equations are discretized by the finite volume method,where the flux at the cell interface is evaluated by local reconstruction of lattice Boltzmann solution from macroscopic flow variables at cell *** new solver removes the drawbacks of conventional lattice Boltzmann method such as limitation to uniform mesh,tie-up of mesh spacing and time interval,limitation to viscous *** is validated by its application to simulate the viscous decaying vortex flow,the driven cavity flow,the viscous flow past a circular cylinder,and the inviscid flow past a circular *** obtained numerical results compare very well with available data in the literature,which show that LBFs has the second order of accuracy in space,and can be well applied to viscous and inviscid flow problems with non-uniform mesh and curved boundary.

关键词： chapman-Enskog analysis flux solver incompressible flow Navier-stokes equation lattice Boltzmann equation

Isolation of Fucoxanthin from the Rhizoid of Laminariajaponica Aresch

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journal of Integrative Plant Biology 2005年第8期47卷 1009-1015页

作者： Wen-jun wang Guang-ce wang Ming ZHANG c. k. TsENG Institute of Oceanology the Chinese Academy of Sciences Qingdao 266071 China Graduate school the Chinese Academy of Sciences Beijing 100039 China Bureau of Environmental Protection of Feixi county in Anhui Province Hefei 231200 China

Fucoxanthin was extracted from the intact rhizoid of Laminariajaponica Aresch with dimethyl sulfoxide （DMsO）, and then recovered from the DMsO extract by partitioning into ethyl acetate and subsequent evaporation. some isolation conditions such as solvent volume and extraction time were screened. The quantity and quality of the extracted fucoxanthin were determined by spectral analysis （absorption spectra and fluorescence emission spectra）. The results indicated that：（1） the average total content of fucoxanthin was 122.1μg in 1 g of fresh L. japonica rhizoid; （2） in comparison with the widely used organic solvent, acetone, DMsO was much more effective for the extraction of fucoxanthin; （3） both DMsO volume and extraction time influenced extraction efficiency such as the recovery rate and purity of fucoxanthin （1 g of fresh L. japonica rhizoid treated with 4 mL DMsO for 60 min, yielded 〉 88% of the total fucoxanthin with purity 0.63）; （4） when （NH4）2sO4 concentration was in the range of 0.5-1.0 mol/L, the pigments rapidly and entirely moved from DMsO into the ethyl acetate phase; （5） the ethyl acetate and DMsO were recycled using a rotary evaporator.

关键词： dimethyl sulfoxide extraction fucoxanthin Laminariajaponica rhizoid.

Wireless actuation and control of ionic polymer-metal composite actuator using a microwave link

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International journal of smart and Nano Materials 2012年第4期3卷 244-262页

作者： j.s.Lee W.Yim c.Bae k.j.kim Department of Mechanical Engineering University of NevadaLas VegasUSA Department of chemistry University of NevadaLas VegasUSA Department of Mechanical Engineering University of NevadaRenoUSA

The ionic polymer–metal composite(IPMc),a type of electroactive polymer(EAP)actuator,has created a unique opportunity to design robots that mimic the motion of biological systems due to its soft structure and operation at a low *** this polymer actuator has strong potential for a next-generation artificial muscle actuator,it has been observed by many researchers that supplying actuation voltages in multiple locations is *** robotic applications,a tethered operation is prohibited and the battery weight can be critical for actual *** this research,the remote unit can provide necessary power and control signals to the target mobile robot units actuated by *** research addresses a novel approach of using a wireless power link between the IPMc and a remote unit using microstrip patch antennas designed on the electrode surface of the IPMc for transmitting the *** modulation of the microwave is proposed to selectively actuate a particular portion of the IPMc where the matching patch antenna pattern is *** approach can be especially useful for long-term operation of small-scale locomotion units and avoids problems caused by complex internal wiring often observed in various types of biologically inspired robots.

关键词： ionic polymer-metal composite actuator microwave link wireless actuation robotic application biomimetic robot