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Comparative studies on Y(Ⅲ)and Dy(Ⅲ)extraction from h.droch.oric and nitric acids by Cyanex 572 as a novel extractant

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Journal of Rare Earth. 2018年第12期36卷 1342-1350页

作者： n.E.El-h.fny M.S.Gasser Sh.Sh.Emam W.h.Mah.oud h.F.Aly h.t Laboratories Centre Atomic Energy Authority Faculty of Science Ain Shams University

Extraction of Y(III) and Dy(III) from h.droch.oric and nitric acids by Cy-572 in kerosene was studied. Th. factors affecting th. extraction were separately investigated. Th. stoich.ometry of th. extracted species was deduced on th. basis of slope analysis meth.d. Evaluation of extraction equilibrium and stripping investigation was studied as well as saponification effect of Cy-572. Th. composition of th. extracted metal species in th. organic ph.se was found to be [MA·(h.)] for Y(III) or Dy(III) in both.media.1.0 mol/L h.I is th. best stripping agent for each.metal ion from th. studied acidic media in one *** Cy-572 does not exh.bit any selectivity towards th. extraction of Y(III) or Dy(III) from both.h.I and h.Osolutions. Based on th. obtained results, th. data were compared and th. separation feasibility between lanth.nides and Y(III) in th. two media was discussed.

关键词： Extraction Cyanex-572 Yttrium Lanth.nides Separation factor Saponification

Experimental and numerical study on plasma nitriding of AISI P20 mold steel

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International Journal of Minerals,Metallurgy and Materials 2016年第9期23卷 1065-1075页

作者： n.nayebpash.ee h.Vafaeenezh.d Sh.Kh.irandish.M.Soltanieh Materials Processing Simulation Laboratory(MPS-LAB) School of Materials and Metallurgical EngineeringIran University of Science and Technology(IUST) Sch.ol of Materials and Metallurgical Engineering Iran University of Science and Technology(IUST)

In th.s study, plasma nitriding was used to fabricate a h.rd protective layer on AISI P20 steel, at th.ee process temperatures（450℃, 500℃, and 550℃） and over a range of time periods（2.5, 5, 7.5, and 10 h., and at a fixed gas n2：h. ratio of 75vol%：25vol%. Th. morph.logy of samples was studied using optical microscopy and scanning electron microscopy, and th. formed ph.se of each.sample was determined by X-ray diffraction. Th. elemental depth.profile was measured by energy dispersive X-ray spectroscopy, wavelength.dispersive spectroscopy, and glow dispersive spectroscopy. Th. h.rdness profile of th. samples was identified, and th. microh.rdness profile from th. surface to th. sample center was recorded. Th. results sh.w th.t ε-nitride is th. dominant species after carrying out plasma nitriding in all strategies and th.t th. plasma nitriding process improves th. h.rdness up to more th.n th.ee times. It is found th.t as th. time and temperature of th. process increase, th. h.rdness and h.rdness depth.of th. diffusion zone considerably increase. Furth.rmore, artificial neural networks were used to predict th. effects of operational parameters on th. mech.nical properties of plastic mold steel. Th. plasma temperature, running time of imposition, and target distance to th. sample surface were all used as network inputs; Vickers h.rdness measurements were given as th. output of th. model. Th. model accurately reproduced th. experimental outcomes under different operational conditions; th.refore, it can be used in th. effective simulation of th. plasma nitriding process in AISI P20 steel.

关键词： tool steel plasma nitriding sputtering neural networks

Sliding Wear Beh.vior of a Grey Cast Iron Surface Remelted by TIG

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Journal of Materials Science & Tech.ology 2009年第5期25卷 622-628页

作者： h.Moh.madzadeh.h.Sagh.fian Sh.Kh.irandish Department of Metallurgy and Materials Engineering Iran University of Science and TechnologyTehranIran

Th. sliding wear beh.vior of a grey cast iron surface remelted by tungsten inert gas （TIG） was studied and compared with.th. unremelted one in th. current work. To evaluate th. wear beh.vior a Pin-on-Disk wear test mach.ne was used. Pins wh.ch.were prepared from th. samples with.th. remelted layers of different th.cknesses of 1.2, 1.8, 2.5 and 3 turn were worn on an AISID3 steel counterface h.ving a h.rdness of 63h.C under th. applied loads of 54, 76 and gg n at a constant sliding velocity of 0.45 m/s. Scanning electron microscopy （SEM） equipped with.energy dispersive X-ray analysis （EDS） and X-ray diffraction （XRD） tech.iques were used to ch.racterize worn surface and subsurface and also wear debris obtained from th. wear tests under different test conditions. Results sh.wed th.t surface remelted grey cast iron h.ve better wear properties for all applied normal loads in comparison with.unremelted ones. Microscopic studies on th. worn surfaces and subsurfaces of samples revealed th.t dominant wear mech.nism for surface remelted samples was mild oxidative, wh.le it was severe for unremelted samples. Increasing remelted layer th.ckness and th.n forming grosser microstructure lead to a decline of wear properties, wh.reas lower th.ckness of remelted layer with.finer microstructure due to h.ving h.gh.r cooling rate th.ough.remelting process can with.tand better against wear.

关键词： Grey cast Iron Surface remelted Tungsten inert gas (TIG) Wear

Optimal deployment sch.dule of an active twist rotor for performance enh.ncement and vibration reduction in h.gh.speed fligh.s

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Ch.nese Journal of Aeronautics 2017年第4期30卷 1427-1440页

作者： young h.YOU Sung n.JUnG Ch.ng J.KIM Department of Aerospace Information Engineering Konkuk University Seoul 05019 Republic of Korea

Th. best active twist sch.dules exploiting various waveform types are sough. taking advantage of th. global search.algorith. for th. reduction of h.b vibration and/or power required of a rotor in h.gh.speed conditions. Th. active twist sch.dules include two non-h.rmonic inputs formed based on segmented step functions as well as th. simple h.rmonic waveform input. An advanced Particle Swarm assisted Genetic Algorith.（PSGA） is employed for th. optimizer. A rotorcraft Computational Structural Dynamics（CSD） code CAMRAD II is used to perform th. rotor aeromech.nics analysis. A Computation Fluid Dynamics（CFD） code is coupled with.CSD for verification and some ph.sical insigh.s. Th. PSGA optimization results are verified against th. parameter sweep study performed using th. h.rmonic actuation. Th. optimum twist sch.dules according to th. performance and/or vibration reduction strategy are obtained and th.ir optimization gains are compared between th. actuation cases. A two-ph.se non-h.rmonic actuation sch.dule demonstrates th. best outcome in decreasing th. power required wh.le a four-ph.se non-h.rmonic sch.dule results in th. best vibration reduction as well as th. simultaneous reductions in th. power required and vibration. Th. mech.nism of reduction to th. performance gains is identified illustrating th. section airloads, angle-of-attack distribution, and elastic twist deformation predicted by th. present approach.s.

关键词： Active twist h.gh.speed fligh. h.b vibration non-h.rmonic Power required

Dry Sliding Oxidative Wear in Plain Carbon Dual Ph.se Steel

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Journal of Iron and Steel Research.International 2007年第4期14卷 43-48页

作者： V Abouei h.Sagh.fian Sh.Kh.irandish Department of Metallurgy and Materials Engineering Iran University of Science and TechnologyNarmak 16844TehranIran

To investigate th. tribological potential of th. dual ph.se （DP） steel as a wear resistant material, th. wear and th. friction ch.racteristics of th.s steel, wh.ch.consists of h.rd martensite islands embedded in a ductile ferrite matrix, h.ve been investigated and compared with.th.se observed in plain carbon h.rdened （h. steel th.t h.s th. same carbon content of 0.2%. Dry sliding wear tests h.ve been carried out using a pin-on-disk wear testing mach.ne at different normal loads of 21.3 n, 28. 5 n, 35.7 n, and 42.6 n and at a constant sliding velocity of 1.20 m/s. Th. analysis of surface and wear debris of samples sh.wed th.t th. wear mech.nism was mainly mild oxidative. Th. friction and th. wear rate of th. h.steel and th. DP Steel h.ve been explained with.respect to th. microstructure and th. wear mech.nism.

关键词： dual ph.se steel wear microstructure h.at treatment

nanoscale potential barrier distributions and th.ir effect on current transport in ni/n type Si Sch.ttky diode

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Journal of Semiconductors 2015年第12期36卷 74-80页

作者： M.Yeganeh.n.Balkanian Sh.Rah.atallah.ur West north.Research.Complex

We h.ve experimentally studied th. ni/n-Si nano Sch.ttky barrier h.igh. （SBh. and potential difference between patch.s in th. nano Sch.ttky diodes （SD） using contact atomic force microscopy （C-AFM） in tapping mode and scanning tunneling microscopy （STM）. Topology measurement of th. surface with.C-AFM sh.wed th.t, a single ni/n-Si SD consists of many patch.s with.different sizes. Th.se patch.s are sets of parallel diodes and electrically interacting contacts of 5 to 50 nm sizes and between th.se individual diodes, th.re exists an additional electric field. In real metal semiconductor contacts （MSC）, patch.s with.quite different configurations, various geometrical sizes and local work functions were randomly distributed on th. surface of th. metal. Th. direction and intensity of th. additional electric field are distributed in h.mogenously along th. contact metal surface. SBh.controls th. electronic transport across th. MS interface and th.refore, is of vital importance to th. successful operation of semiconductor devices.

关键词： nano Sch.ttky diode additional electrical field nanopatch STM and C-AFM

Tameness and Artinianness of Graded Generalized Local Coh.mology Modules

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Algebra Colloquium 2015年第1期22卷 131-146页

作者： M. Jah.ngiri n. Sh.rmoh.mmadi Sh. Tah.mtan Faculty of Math.matical sciences and Computer Kharazmi University rlbhran Iran School of Mathematics Institute for Research in Fundamental Sciences (IPM) P.O. Box 19395-5749 Tehran Iran Sch.ol of Math.matics Institute for Research in Fundamental Sciences (IPM) P.O. Box 19395-5749 rlbhran Iran Department of Mathematics University of Tabriz Tabriz Iran Islamic Azad University Borujerd Branch Boroujerd Iran

Let R = ⊙n〉0 Rn be a standard graded ring, a ∩ ⊙n〉0 Rn an ideal of R, and M, n two finitely generated graded R-modules. Th.s paper studies th. h.mogeneous components of graded generalized local coh.mology modules. We sh.w th.t for any i 〉 0, th. n-th.graded component h.α（M, n）n of th. i-th.generalized local coh.mology module of M and n with.respect to a vanish.s for all n 〉〉 0. Some sufficient conditions are pro- posed to satisfy th. equality sup{end（h.α （M, n）） [ i _〉 0} = sup{end（h.R＋（M, n））｜ i 〉 0}. Also, some sufficient conditions are proposed for th. tameness of h.α（M, n） such.th.t i = fRα＋（M,n） or i = cdα（M,g）, wh.re fRα＋（M,n） and cdα（M,g） denote th. R＋- finiteness dimension and th. coh.mological dimension of M and n with.respect to a, respectively. Finally, we consider th. Artinian property of some submodules and quotient modules of h.α（M, n）, wh.re j is th. first or last non-minimax level of h.α（M, n）.

关键词： graded rings and modules generalized local coh.mology Artinian modules,tameness

A Study on th. Wear Beh.viour of Dual Ph.se Steels

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Journal of Materials Science & Tech.ology 2007年第1期23卷 107-110页

作者： V.Abouei h.Sagh.fian Sh.Kh.irandish.Kh.Ranjbar Department of Metallurgy and Materials Engineering Iran University of Science and TechnologyIran Sh.h.d Ch.mran University Iran

Dual ph.se （DP） steels containing four different amounts of martensite ranging from 43 vol. pct to 81 vol. pct h.ve been developed from 0.2 wt pct carbon steel by intercritical h.at treatment at a fixed temperature of 780℃ with.varying h.lding times followed by water quench.ng. Dry sliding wear tests h.ve been conducted on DP steels using a pin- on-disk mach.ne under different normal loads of 61.3, 68.5, 75.7 and 82.6 n and at a constant sliding speed of 1.20 m/s. At th.se loads, th. mech.nism of wear is primarily delamination, wh.ch.h.s been confirmed by SEM micrograph. of subsurface and wear debris of samples. Wear properties h.ve been found to improve with.th. increase in martensite volume fraction in dual ph.se steels.

关键词： Wear Dual ph.se steel Microstructure

Quantifying th. Microstructures of Pure Cu Subjected to Dynamic Plastic Deformation at Cryogenic Temperature

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Journal of Materials Science & Tech.ology 2011年第8期27卷 673-679页

作者： F. Yan h. W. Zh.ng n.R. Tao K. Lu sh.nyang national Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

A pure Cu （99.995 wt%） h.s been subjected to dynamic plastic deformation at cryogenic temperature to a strain of 2.1. Th.ee types of microstructures th.t are related to dislocation slip, twinning and sh.ar banding h.ve been quantitatively ch.racterized by transmission electron microscopy （TEM） assisted by convergent beam electron diffraction （CBED） analysis. Microstructures originated from dislocation slip inside or outside th. sh.ar bands are ch.racterized by low angle boundaries （〈15°） th.t are spaced in th. nanometer scale, wh.reas most deformation twins are deviated from th. perfect ∑3 coincidence （60°/〈111〉） up to th. maximum angle of 9°. Th. quantitative structural ch.racteristics are compared with.th.se in conventionally deformed Cu at low strain rates, and allowed a quantitative analysis of th. flow stress-structural parameter relationsh.p.

关键词： Quantitative structural ch.racterization Cu Dynamic plastic deformation Trans mission electron microscopy Convergent beam electron diffraction