周谦莉
,
杜挺
金属学报
利用下列组装的固体电解质定氧电池Mo/Cr,Cr_2O_3//ZrO_2(MgO)//[O],Ce_2O_2S/Mo+ZrO_2金属陶瓷,Mo.在1600℃温度下对含微量C的Fe-Nb-Ce溶液进行热力学性质的研究。实验测得1600℃时Fe液中反应Ce_2O_2S=2[Ce]+2[O]+[S]的平衡常数和Ce_2O_2S的标准生成自由能分别为K=4.395×10~(-15),ΔG°_(Ce_2O_2S)=-514.786kJ·mol~(-1);Ce与Nb的活度相互作用系数为e_(Nb)~(Ce)=-2.306,e_(Ce)~(Nb)=-3.481。 随着Nb含量的增加,在微量碳含量的条件下,产物中存在NbC化合物,本文对NbC的生成问题进行了探讨,并得到1600℃时,Fe液中NbC的标准生成自由能为ΔG°_(NbC)=-87.111kJ·mol~(-1)。
关键词:
Fe-Nb-Ce溶液
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thermodynamic properties
,
oxygen
,
sulphur
,
carbon
Zhiyu QIAO Xianran XING Shuzhen DUAN University of Science and Technology Beijing
,
Beijing
,
100083
,
ChinaChaogui ZHENG Beijing University
,
Beijing
,
100871
,
China
材料科学技术(英文)
A new geometric asymmetric model for predicting the thermodynamic properties of ternary system from three sub-binaries is presented in this paper.Its analytical expression with good calculating ac- curacy is most simple in all asymmetric models.The new model was applied to predict the enthalpies of mixing of the Bi-Ga-Sn.Au-Ag-Sn and NaCl-KCl-CaCl_2 ternary systems which were in good agreements with experimental data.Based on thermodynamic principles,the importance of the choice of asymmetric component is also discussed.The error analysis indicates that in the case of judging the asymmetric component in ternary system according to the thermodynamic criterion the deviation is minimum.It is of great significance to improve the calculating accuracy for predicting thermodynamic properties of ternary solution phase from the sub-binary ones.
关键词:
thermodynamic properties
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null
,
null
LI Ruiqing General Research Institute for Non-ferrous Metals
,
Beijing
,
China.
材料科学技术(英文)
In this paper, the activities of components of Ga-Sb system have been calculated from its phase diagram by using computer program CABPD (calculating activities from binary phase diagrams) presented by us in previous paper. The excess free energy of liquid solution can be expressed as: ΔG_m=X_(Ga)X_(Sb)(4392+17022X_(Sb)-15138X_(Sb)) J/mol In order to verify the reliability of calculated results, a discriminant has been proposed.
关键词:
Ga-Sb alloy
,
null
ZHOU Qianli DU Ting Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China Senior engineer
,
Central Iron and Steel Research Institute
,
Ministry of Metallurgical Industry
,
Beijing
,
China
金属学报(英文版)
The solid oxide electrolyte galvanic cell represented by Mo/Cr,Cr_2O_3//ZrO_2(MgO)//[O], Ce_2O_2S/Mo+ZrO_2 ceramic-metal,Mo have been used to study the thermodynamic proper- ties of Fe-Nb-Ce solution containing trace carbon at 1600℃.The equilibrium constant for the reaction Ce_2O_2S=2[Ce]+2[O]+[S] and the standard free energy of formation of Ce_2O_2S have been determined in liquid iron at 1600℃ as K=4.395×10~(-15).ΔG_(Ce_2)O_2S=-514.786 kJ·mol~(-1).The interaction coefficients between cerium and niobium are found to he e_(Nd)~(Ce)=-2.306,e_(Nd)~(Ce)=-3.481. The equilibrium products began to contain the compound NbC with the increase of Nh concentration in the condition of trace carbon.The formation of NbC is discussed in this work.The standard free energy of formation of NbC in liquid iron at 1600℃ have been de- termined as ΔG_(NbC)=-87.111 kJ·mol~(-1).
关键词:
Fe-Nb-Ce liquid solution
,
null
,
null
,
null
,
null
雷霞
,
段远源
,
史琳
,
朱明善
,
韩礼钟
工程热物理学报
HFC-227ea是一种有希望的新环保制冷剂,特别是作为混合物中的一种组元用于R22和R502的替代,但其热物性数据十分有限。本文使用膨胀定容法高精度地测量了HFC-227ea的气相PVT性质,沿定温线外推确定了其第二和第三维里系数,并与文献值进行了比较;使用截断维里方程,根据本文所确定的维里系数,可以高精度地再现HFC-227ea的气相区热力性质
关键词:
维里系数
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PVT性质
,
HFC-227ea
,
热力学性质
谭心
,
王洋洋
,
贾亦超
,
李瑜庆
,
穆庆鸽
材料导报
doi:10.11896/j.issn.1005-023X.2015.04.030
基于平面波赝势的第一性原理方法,对TiN的B1(NaCl)和B2(CsCl)以及B3(闪锌矿)复合结构的力学性能以及焓与压力之间的关系进行了研究,并讨论了它们的相对稳定性.通过研究分析可知,TiN在347 GPa左右时会发生从B1到B2的结构相变,在-17.5 GPa左右时会发生从B1到B3的结构相变.由声子频率对压强的依赖关系可知频率和带隙随着压力的增加而增加.另外高温区TiN的热膨胀系数受温度的影响较小.
关键词:
第一性原理
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相变
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热力学性质
,
振动
李慎兰
,
程宏辉
,
邓小霞
,
陈伟
,
陈德敏
,
杨柯
稀有金属材料与工程
研究了Cu含量变化对Lao.6Nd0.4Ni4.8Mn0 2Cux(x=0,0.1,0.2,0.3,0.4)合金系的晶胞参数、热力学性能以及贮氢性能的影响,讨论了晶胞参数与吸放氢平台压力以及吉布斯自由能之间的关系.研究结果表明,随着Cu含量的增加,晶胞参数á增加,c减小,晶胞体积先增大后减小;吸放氢平台压力随着晶胞参数á的增加呈线性降低;La0.6Nd0.4Ni4.8Mn0.2Cux合金的Seitz半径随着Cu含量的增加而减小,并且与△Sd/△Hd之间呈现非常好的线性关系,与△Sa/△Ha之间存在双曲线关系.
关键词:
贮氢合金
,
非化学计量比
,
平台压力
,
晶胞参数
,
热力学性能
黄多辉
,
李强
,
曹启龙
,
王藩侯
,
蔡灵仓
,
张修路
,
经福谦
稀有金属材料与工程
使用第一性原理方法结合准谐近似理论研究了立方结构钨的热力学性质,包括平衡体积V、体弹模量BO、线膨胀系数α、熵S、振动自由能F、等压热容CP和等容热容Cv随温度的变化关系.在计算体系的线膨胀系数、熵、振动自由能、等压热容和等容热容时考虑了热电子和热振动对自由能的贡献.计算结果表明:考虑热电子对自由能贡献后得到的线膨胀系数、熵、振动自由能和等压热容在0~2000 K范围内均与实验值符合较好.在得到平衡体积随温度变化的基础上,计算了钨立方结构的弹性性质,得到了弹性常数、体积模量、剪切模量和杨氏模量随温度的变化关系,所得结果与实验测量值符合较好.
关键词:
W
,
准谐近似
,
热力学性质
,
弹性性质
何建云
,
黄洁
,
宋纪蓉
,
赵毅莎
,
马聪
,
徐抗震
应用化学
doi:10.3724/SP.J.1095.2013.20401
以PEG-400为催化剂,利用氯甲酸乙酯和硫氰酸钾反应生成的乙氧酰基异硫氰酸酯为中间体与2,4-二硝基苯肼反应,得到N-(乙氧酰基)-N′-(2,4-二硝基苯胺基)硫脲,通过IR、元素分析等方法对其结构进行了表征.在室温条件下,采用缓慢挥发法培养出适合用于X射线衍射测试的单晶.晶体结构数据表明,晶体属单斜系,P2(1)/c空间群,晶胞参数:a=4.1919(2) nm,b =12.295(6) nm,c =23.828(11) nm,α=y=90.00°,β=92.467(10)°,V=1439.7(12),Dc=1.519 g/cm3,μ=0.263 cm-1,F(000) =680,Z=4,R1=0.1121,wR2 =0.2540.并对标题化合物进行了热重分析和比热容测定,计算了热力学函数;证明该化合物有良好的热稳定性.
关键词:
合成
,
X单晶衍射
,
晶体结构
,
比热容
,
热力学性质