X L Tian1)
,
Y M Sun1)
,
S X Zhao1)and X C Chen2) 1) College of Materials Science and Engineering
,
Shandong University of Technology
,
Jinan 250061
,
China2) Institute of Physics
,
The Chinese Academy of Sciences
,
Beijing 100081
,
China
金属学报(英文版)
Thethermal parameterofthe bulk amorphous Zr41 Ti14 Ni10 Cu12 5 Be22 5 alloy thermal dif fusivity,thermalcapacity andcoefficientofthermalconductivityatthestateofsolid andsu percooled liquid hasbeen measuredinthisstudy.It wasfoundthatthecoefficientofthermalconductivity and thethermalcapacity vary significantly with temperature. An error occursinthe measurementofthecoefficientofthethermalconductivity andthethermalcapacity us ing the method adoptedin this paper bothintheglasstransition processand when crystalliza tion processappears.
关键词:
Zr41Ti14Ni10Cu12 5Be22 5
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null
,
null
NING Yuantao LI Yongnian Kunming Institute of Precious Metals
,
Kunmmg
,
China Professor
,
Kunming Institute of Precious Metals
,
Kunming
,
Yunnan
,
China
金属学报(英文版)
The internal oxidation behavior of Pd-40Ag-1M(M=Zr,Y)alloy wires has been studied in air at 800—1200℃.The relationship between the internal oxidation depth ξ and the reaction time t can be expressed as ξ= Kt~n,where n=0.5—0.75.The higher the temperature,the larger the value of n is.The active elements Zr and Y show different internal oxidation characters.For the alloys eontaining Zr,the oxidation rate along the grain boundaries is about twice as high as that in grains,and“lateral oxidation”exists along the grain boundaries.For the alloys containing Y,the oxidation rates in grains and along the grain boundaries are roughly the same,and there is no“lateral oxidation”along the grain bounda- ries.The activation energies of both alloys are in the range of 120—150kJ/mol.Some prop- erties for oxidized alloys were studied.The mechanisms of the internal oxidation were dis- cussed.
关键词:
Pd-40Ag alloy
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null
,
null
,
null
,
null
王龙章
,
黄克雄
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骆如铁
,
姚渝
,
叶大陆
,
陈新民
金属学报
本文讨论了双金属共存体系M_1-M_2-x-y,当两种金属的化合物相互作用生成多金属化合物时,优势区相图的绘制原理、方法及计算机程序。通过绘制Zn-Fe-SO系的优势区相图,分析了ZnO·Fe_2O_3的生成及稳定条件,并说明了其在硫化锌矿焙烧中的指导作用。
关键词:
M_1-M_2-x-y体系
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predominance diagram
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roasting
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zinc sulfide ore
宁远涛
,
李永年
金属学报
在800—1200℃大气气氛中研究了直径0.1-2.0mmPd-40Ag-1Zr和Pd-40Ag-1Y合金丝的内氧化行为及其对性能的影响、内氧化深度ξ与反应时间t的关系可以表示为ξ=Kt~n,其中反应指数n=0.5-0.75。温度越高,n值越大,对内氧化抛物线规律偏离越大,活性元素Zr和Y有不同内氧化特性:含Zr合金晶界氧化速度比晶内氧化约快一倍,且沿晶界存在“侧氧化”;含Y合金晶界与晶内氧化速度相差不大,不存在沿晶界的“侧氧化”。两种合金的内氧化激活能在120—150kJ/mol范围内。讨论了两种合金的内氧化机制。
关键词:
Pd-40Ag合金
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Y
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Zr
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internal oxidation
沈建宇
,
王丽
,
王颖
,
金玉秀
,
方敏华
稀土
doi:10.16533/J.CNKI.15-1099/TF.201601004
为探究纳米钙钛矿型复合氧化物ABO3中不同B位元素及Cu的掺杂量对催化剂的结构、形貌、表面性质和催化活性的影响规律及原因,并优化出具有更好活性的催化剂,采用柠檬酸-溶胶-凝胶法制备得到8个钙钛矿型复合氧化物Y07Ce01Sr02Fe1-xCuxO3和Y07Ce01Sr0.2Mn1-xCuxO3(x=0.1～0.4),通过X射线衍射(XRD)、扫描电镜(SEM)、比表面积(BET)、X射线光电子能谱(XPS)等分析方法对其进行了表征,并测试了8个样品对CO+NO的催化活性.结果表明,在Fe、Mn两个系列中,x=0.3时的两个样品对CO+ NO分别具有最高的催化活性,Y07Ce0.1 Sr02Fe07Cu03O3对NO和CO的转化率均在225℃时达到100％,而Y07Ce01Sr02Mn07Cu0.3O3对NO和CO的转化率则分别在325℃和225℃时达到100％.Y07Ce01Sr0.2 Fe07Cu03O3的催化活性优于Y07Ce0.1 Sr0.2Mn07Cu003O3,这是由于Fe4 +/Fe3的摩尔比高于Mn4 +/Mn3,并且Y07Ce0.1 Sr0.2 Fe07Cu03O3中所有Ce4 +/Ce3+、Cu+/Cu2+和OA/OL的摩尔比均高于Y07Ce01Sr0.2Mn07Cu03O3中相应的摩尔比,而这些因素均有利于NO+ CO的催化活性.通过适量的Cu取代B位离子可提高催化剂对NO+ CO的氧化还原性,同时Cu的掺杂对于Fe、Mn两个系列中OA/O1的摩尔比具有不同的影响.
关键词:
纳米钙钛矿型氧化物
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CO+NO
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催化活性
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催化机理
王塞北
,
邱红莲
,
张吉明
,
胡洁琼
,
王松
,
陈永泰
,
悟有才
,
魏宽
,
谢明
贵金属
采用基于密度泛函理论的第一性原理赝势平面波方法，计算了Au-Pd-M(M=Mo, Y, Zr)合金中可能存在的各种合金相的结合能与生成焓，讨论了合金相的稳定性。结果表明，Au-Pd-M固溶体中，添加质量比为1%的Mo元素形成的固溶体，其结合能与生成焓是Au-Pd-M(M=Mo, Y, Zr)系固溶体中最低的。Au-Pd-Y系合金中最为稳定的中间相是YPd3。Au-Pd-Zr系合金中，形成PdZr2的反应最容易发生，生成的合金相惁是最为稳定的，其次是AuZr3。
关键词:
金属材料
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第一性原理
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Au-Pd-M(M=Mo, Y, Zr)
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固溶体
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中间相
Physical Review B
The magnetic properties of 13-atom M clusters (M=Y, Zr, Nb, Mo, and Tc) with three possible high-symmetry geometries have been studied using the discrete-variational local-spin-density-functional method. While the ground states of most transition-metal 13-atom clusters correspond to the icosahedral structure, we found that the cuboctahedral structure is more energetically stable than the icosahedral one for Mo-13 and Tc-13 clusters. The ground states of all the clusters are shown to be magnetic, but their magnetic moments are not striking.
关键词:
rhodium clusters;metal-clusters;molecules;symmetry;states
王桂英
,
唐永刚
,
毛强
,
郭腾
,
刘宁
,
彭振生
稀有金属
doi:10.13373/j.cnki.cjrm.2014.03.007
用固相反应法制备了Y1-xDyxCrO3(z =0,0.1)多晶样品.通过X射线衍射(XRD)图谱检测了样品的结构,测量了样品的磁性,作了磁化强度-温度(M-T)曲线、磁化强度-磁场(M-H)曲线,研究了Dy3替代Y3+对Y1-xDyxCrO3体系磁性质的影响.结果表明,Dy3替代多铁性YCrO3中的Y3+对YCrO3的磁性有效大影响.YCrO3在奈尔温度TN=139 K以下呈倾角反铁磁,显示弱铁磁性;Dy3+替代y3+后的Y0.gDy0.1CrO3样品,在50 K＜T＜142K温区,少量Dy3+在两相邻Cr3+产生的倾角反铁磁内场作用下沿内场反方向排列,使铁磁性减弱;在T＜50 K温区,Dy3+-O2--Dy3+层的铁磁性与Cr3+-O2--Cr3+层的铁磁性耦合,铁磁性增强.
关键词:
多铁性材料
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Dy替代
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磁性质
Ying LI
材料科学技术（英文）
Oxide materials NaCo2O4 and (Na1-yMy)1.6Co2O4 (M=K, 0.05≤y≤0.35; M=Ca, Sr, 0.10≤y≤0.40) were prepared by a sol-gel method. Experimental results indicated that the Seebeck coefficient and the Power-factor of Na Co2O4 were improved by doping Ca and Sr but not by K. The Power-factor of NaCo2O4 is in its maximum, 1.68×10-4 W•m-1•K-2 and 11% bigger than that of the original one when the dopant fraction of Ca was 0.1. Doping Sr makes NaCo2O4 have the biggest Power-factor, 1.68×10-4 W•m-1•K-2 that is 50% bigger than the non-doping oxide. The experimental results indicate that suitable dopants and addition amounts could improve the thermoelectric properties of NaCo2O4 greatly.
关键词:
Thermoelectric materials
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materials
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Electric
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proper
