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Effect of 2–6 at.% Mo addition on microstructural evolution of Ti-44Al alloy

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Journal of Materials science & Technology 2018年第7期34卷 1196-1204页

作者： s.Z.Zhang Z.W.song J.C.Han C.J.Zhang p.Lin D.D.Zhu F.T.Kong Y.Y.Chen school of Materials science and Engineering Taiyuan University of Technology shanxi Key Laboratory of Advanced Magnesium-Based Materials Taiyuan University of Technology school of Mechanical Engineering Taiyuan University of Technology school of Mechanical Engineering Quzhou University state Key Laboratory for Advanced Welding and Jointing Harbin Institute of Technology

In order to understand the effect of Mo alloying on the microstructural evolution of TiAl alloy, the as-cast microstructure, heat treated microstructure characteristic, and hot compression microstructure evolution of Ti-44Al alloy have been studied in this work. The as-cast microstructure morphology changes from （γ＋α2） lamellar colony and β/β0＋γ mixture structure to β/β0 phase matrix widmannstatten structure, when Mo content increases from 2 at.% to 6 at.%. Affected by the relationship between β phase and α90℃phase, the angles between the lamellar orientation and the block β/β0 phase are roughly at 0℃, 45℃ and 90℃. Comparing with heat treatment microstructure, the hot compression microstructure contains less β/β0 phase, however, theβ/β0 phase containing 2Mo alloy and 3Mo alloy hot compressed at 1275 ℃ has the inverse tendency. In addition, （α2 ＋γ） colony is decomposed by the discontinuous transformation.2017 published by Elsevier Ltd on behalf of The editorial office of Journal of Materials science ＆ Technology.

关键词： phase transformation Titanium aluminides Heat treatment Microstructure evolution,β/βo phase

A Note on the singular Limit of the Exact Controllability of Dissipative Wave Equations

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Acta Mathematica sinica,English series 2000年第4期16卷 601-612页

作者： Yuping Tang Xu Zhang Department of Mathematics, Daxian Teacher’s College, Daxian 63500 sichuan. p. R. China school of Mathematics, sichuan University. Chengdu 610064. sichuan. p. R. China Academy of Mathematics and systems sciences, Chinese Academy of sciences Beijing 100080. p. R. China Department of Mathematics Daxian Teacher's College Daxian 635000 Sichuan P. R. China school of Mathematics Sichuan University Chengdu 610064 Sichuan P. R. China Academy of Mathematics and systems sciences Chinese Academy of Sciences Beijing 100080 P. R. China

In this note we analyze the exact controllability of singularly perturbed damped wave equations under more general geometric control condition than that of [1]. We show that the null controllability of the heat equati... 详细信息

关键词： Controllability singular perturbation Heat equation Wave equation

Workability studies in Forming of sintered Fe-0.35Cpowder Metallurgy preform During Cold Upsetting

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Journal of Iron and steel Research(International) 2011年第12期18卷 71-78页

作者： s Narayan A Rajeshkannan school of Engineering and physics Faculty of ScienceTechnology and EnvironmentUniversity of the South Pacific(Laucala Campus)

An experimental investigation on the workability behaviour of sintered Fe-0.35C steel preforms under cold upsetting,have been studied in order to understand the influence of aspect ratio and lubrication condition on the workability *** above mentioned powder metallurgy sintered preform with constant initial theoretical density of 84% of different aspect ratios,namely,0.4 and 0.6 respectively were prepared using a suitable die-set assembly on a 1 MN capacity hydraulic press and sintered for 90 min at 1200 ℃.Each sintered preform was cold upset under nil/no and graphite frictional constraint,*** the condition of triaxial stress densification state,axial stress,hoop stress,hydrostatic stress,effective stress and formability stress index against axial strain relationship was established and presented in this *** more,attained density was considered to establish formability stress index and various stress ratio parameters behaviour.

关键词： powder metallurgy failure analysis plastic behaviour workability

path Integral solution for an Angle-Dependent Anharmonic Oscillator

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Communications in Theoretical physics 2012年第7期58卷 12-18页

作者： s.Haouat LpTh Department of PhysicsUniversity of JijelBP 98Ouled Aissa18000 JijelAlgeria

We have given a straightforward method to solve the problem of noncentral anharmonic oscillator in three dimensions. The relative propagator is presented by means of path integrals in spherical coordinates. By making an adequate change of time we are able to separate the angular motion from the radial one. The relative propagator is then exactly calculated. The energy spectrum and the corresponding wave functions are obtained.

关键词：路径积分非谐振子积分解球坐标系振荡器非中心角运动波函数

Dynamics of Humic substance-Complexed Copper and Copper Leaching During Composting of Chicken Manure

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pedosphere 2010年第2期20卷 245-251页

作者： A.s.ALI College of Resource and Environment Northwest A & F University

Chicken manure was composted for 110 d to evaluate changes in organic carbon (C) and humic substance-complexed copper (Hs-Cu) extracted with water,sodium hydroxide (NaOH),and sodium pyrophosphate and sodium hydroxide mixture (Na 4 p 2 O 7-NaOH).The average Hs-Cu content from the Na 4 p 2 O 7-NaOH extraction accounted for 46.8% of the total Cu in the compost,followed by those from the NaOH and water extractions,which accounted for 34.5% and 6% of the total Cu in the compost,***-Na 4 p 2 O 7-extractable Hs-Cu increased throughout the composting ***-extractable Hs-Cu increased during the first 50 d of composting and then leveled ***-extractable Hs-Cu enhanced during the first 21 d and then ***-extractable Hs-Cu was not correlated to NaOH-or NaOH-Na 4 p 2 O 7-extractable organic *** average amount of Cu leached from the compost was about 20% of the total Cu in the chicken manure and Cu leaching increased during the first 35 d of composting and then *** of Cu was significantly correlated to the concentrations of Hs-Cu extracted with NaOH and water,but was not correlated to the concentration of Hs-Cu extracted with NaOH-Na 4 p 2 O ***,NaOH-and water-extractable Hs-Cu were relatively labile and NaOH-Na 4 p 2 O 7-extractable Hs-Cu was relatively *** process after rapid decomposition could result in low potential of Cu leaching because of formation of more NaOH-Na 4 p 2 O 7-extractable Hs-Cu.

关键词：堆肥过程浸出过程络合铜腐植物质鸡粪腐殖酸氢氧化钠水提取物

Cu/NbC纳米复合材料的原位合成及其在电触头材料应用中的功能梯度行为（英文）

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Transactions of Nonferrous Metals society of China 2015年第3期25卷 863-872页

作者： s.GHOLAMI sHIRI p.ABACHI K.pOURAZARANG M.MOHAMMADI RAHVARD Department of Materials science and Engineering Sharif University of Technology Damavand petrochemical Company Phase 2Pars Special Economic Energy Zone school of Materials science and Engineering and Center of Excellence for High strength Alloys Technology Iran University of Science and Technology

原料Cu,Nb和石墨粉末置于高能振动盘式研磨仪,在氩气气氛中研磨7 h制备Cu-5%NbC(体积分数)粉末。采用两步压制法及在真空900℃烧结1h条件下制得Cu-NbC功能梯度材料和复合材料样品,研究样品的显微组织、物理性能和力学性能。场发射扫描... 详细信息

原料Cu,Nb和石墨粉末置于高能振动盘式研磨仪,在氩气气氛中研磨7 h制备Cu-5%NbC(体积分数)粉末。采用两步压制法及在真空900℃烧结1h条件下制得Cu-NbC功能梯度材料和复合材料样品,研究样品的显微组织、物理性能和力学性能。场发射扫描电镜、能量色散X射线和X射线衍射结果表明,样品经烧结处理后,晶粒尺寸为18~27 nm的纳米结构基体中含有大小为42 nm的纳米颗粒增强相,证实了所制复合材料的高温热稳定性。Cu-15%NbC复合材料样品的硬度是纯Cu样品硬度的5倍。相对于纯Cu样品,磨损后Cu-15%NbC复合材料样品的体积磨损量减小,且电导率降低至36.68%IACs。相对于复合表面中的复合材料样品,Cu/NbC功能梯度材料样品在具有与复合材料相同的硬度和磨损性能的条件下,显示出75.83%IACs的较高电导率。因此,具有良好力学性能和电学性能的Cu/NbC功能梯度材料将成为很好的电触头材料。

关键词： Cu/NbC纳米复合材料原位复合材料机械合金化电触头磨损性能

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τ lepton decay

Chinese physics C 2010年第6期34卷 896-901页

作者： s.Eidelman Budker Institute of Nuclear physics Siberian Branch of Russian Academy of Science Novosibirsk state University

We discuss recent results on τ lepton physics obtained at the BABAR, Belle and KEDR detectors They include tests of lepton universality using new measurements of T lepton mass and some branching fractions Also descri... 详细信息

关键词： lepton universality lepton mass measurements hadronic branching fractions

GLOBAL EXIsTENCE FOR A CLAss OF sYsTEMsOF NONLINEAR WAVE EQUATIONs INTHREE spACE DIMENsIONs

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Chinese Annals of Mathematics,series B 2004年第4期25卷 463-482页

作者： s.KATAYAMA Department of Mathematics Wakayama University930 SakaedaniWakayama 640-8510Japan.onsider a system of nonlinear wave equationsfor i = 1 … m where F (i = 1 … m) are smooth functions of degree 2 near the origin of their arguments and u = (u1 …um) while u and x u represent the first and second derivatives of u respectively. In this paper the author presents a new class of nonlineaxity for which the global existence of small solutions is ensured. For example global existence of small solutions for arbitrary cubic termsarbitrary cubic termswill be established provided that c12 ≠c22.

Consider a system of nonlinear wave equations (e)2t-c2i△xui=Fi(u,(e)u,(e)x(e)u) in (0,∞)×(R)3 for i=1,┈,m,where Fi(i=1,┈,m) are smooth functions of degree 2 near the origin of their arguments, and u=(u1,┈,um),while (e)u and (e)x(e)u represent the first and (second derivatives of u, respectively. In this paper, the author presents a new class of nonlinearity for which the global existence of small solutions is ensured. For example, global existence of small solutions for((e)2t- c21Δx)u1 = u2((e)tu2) + arbitrary cubic terms,((e)2t - c22Δx)u2=u1((e)tu2) + ((e)tu1)u2 + arbitrary cubic termswill be established, provided that c21 ≠ c22.

关键词：波动方程倍数处处存在偏微分方程非线性

poles of L-Functions on Quaternion Groups

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Chinese Annals of Mathematics,series B 2014年第4期35卷 519-526页

作者： ?etin üRTs Department of Mathematics TOBB University of Economics and Technology Ankara Turkey

The author shows that the(partial) standard Langlands L-functions on quarternion groups have at most simple poles at certain positive integers.

关键词：四元数群正整数数学教学教材