共查询到19条相似文献,搜索用时 187 毫秒
1.
建立了由三个侧边二元系的过剩Gibbs自由能计算三元系过剩Gibbs自由能的正确溶液数学模型,从已知二元系的过剩自由表达式计算三元系的过剩自由能,分别计算了Mg-Cu-Ni,Cd-Bi-Pb,Zn-In-Cd3个体系的过剩自由能,与文献值很好的相符。 相似文献
2.
根据Cd-Sn合金相图、电阻率、热容量、偏摩尔熵和粘度,确定该合金熔体的结构单元为Cd原子,Sb原子以及Cd3Sb2,Cd4Sb3和CdSb化合物。基于以上结构单元,并依据含化合物金属熔体的共存理论,推导了Cd-Sb合金熔体的作用浓度计算模型。理论计算的Ncd,与实测的Cd的活度值a(cd),完全一致。同时也计算出了以上3种化合物的标准自由能。 相似文献
3.
本文论述了lCP-AES法测定蚕茧中的K、Na、Ca、Mg、Fe、Al、Mn、Si、Cu、Zn、B等微量元素的方法,采用微波炉密封罐溶解技术,考察了光谱、基体干扰及酸度、粘度的影响,并测定了实际样品.方法简单易行. 相似文献
4.
考察了以卤素化合物为第三组分对NdCl3·nTBP/MgCl2-Al(i-Bu)3体系催化异戊二烯聚合的影响。结果表明,各种卤素化合物的活性顺序为Al2(i-Bu)3Cl3≈ClCH2—CH=CH2>Si(CH3)2Cl2>AlEt2Cl>TiCl4;以Al2(i-Bu)3Cl2或ClCH2-CH=CH2作第三组分,采用Ip-Al-Nd三元陈化,Cl单加或内添加卤素化合物方式,均可以提高催化活性,聚合转化率在Cl/Nd值为1-6的范围内基本保持不变。经IR和13C-NMR测定表明,除St(CH3)2Cl2外,第三组分对聚合物的微观结构影响不大。 相似文献
5.
采用电流斜波法测试了4种不同金属化样品,其n值分别为2.29(Al-Si合金膜),1.25(Al-Si-Cu合金膜),1.28(Al-Si/Ti双层金属化),1.23(Al/TiWTi/Al多层金属化)结果表明,n值与材料有关,电迁徒阻力越高n值越小,与BLACK方程相符,同时,考察了不同温度和不同电流上升斜率对n值测量结果的影响,试验表明,在相当宽度的温度范围和测试时间内获得n值一致性很好。 相似文献
6.
若干新型硫卤系统玻璃的形成 总被引:1,自引:0,他引:1
对As2Se3-GeTe-AgX(X=Cl,Br.I),As2Se3-Gete-CulI,AsSe3-AgI-CuI五个新的硫卤系统玻璃的形成能力进行了研究,确定了这些系统的玻璃形成区,并测定了区分玻璃的特征温度。结果表明;在As2Se3-GeTe-AgX系统中,X由Cl到I,玻璃的形成范围依次增加。 相似文献
7.
本文论述了ICP-AES法测定蚕茧中的K、Na、Ca、Mg、Fe、Al,Mn、Si、Cu、Zn、B等微量元素的方法,采用微波炉密封罐溶解技术,考察了光谱、基体干扰及酸度、粘度的影响,并测定了实际样品。方法简单易行。 相似文献
8.
对比研究了75Si-Fe和Si-Ca、Si-Ba、Si-Ca-Al等硅基复合孕育剂对铸态球铁金相组织和机械性能的影响.结果表明,Si-Ca、Si-Ba、Si-Ca-Ba-Al等硅基复合孕育剂的孕育效果均优于75Si-Fe,在等强度条件下,明显地提高球铁的延伸率 相似文献
9.
闵乐泉 《北京科技大学学报(英文版)》1996,(2)
提出了处理数字化图像的光滑算子。用它处理了Al-Mn-Si二十面体准晶的高分辨电子显微图,处理后的图像展示了周期结构特征,由此建立了一个平面周期模型,其Fourier变换图符合Al-Mn-Si准晶相应的电子衍射图。 相似文献
10.
已知在加氢汽油介质中Ni(naph)2-Al(i-Bu)3-(BF3·OEt2+n-C8H17OH)体系为胶体催化剂。本工作应用FT-IR谱结合Tyndal效应、电导率、UV-Vis、ESR谱对催化剂各组分的相互作用进行研究。得出Ni(naph)2被Al(i-Bu)3还原的主要产物是Ni0;被Al(i-Bu)2OiBu还原的主要产物是Ninaph。Ni0聚结成胶粒(Ni0)n,胶粒表面的Ni0或吸附的Ni+是活性中心组分,与(i-Bu)2AlBF4形成配合物,给出了活性中心模型。丁二烯具有稳定胶粒的作用。 相似文献
11.
JianZhang 《北京科技大学学报(英文版)》2002,9(3):170-176
Based on the phase diagrams,measured activities and the annexation principle,calculating models of mass action concentrations for In-Bi-Cu and In-Sb-Cu melts have been formulated.Calculated results not only agree well with practical values,but also obey the mass action law,showing that the deduced model can reflect the structural reality of given melts and that the annexation principle is applicable to these two ternary metallic melts.So long as there is one from three binary systems constituting the ternary melts,in which the activities of one component exhibit positive deviation relative to Raoultian behavior,heterogeous melts inevitably would form,soheterogeneous calculating model should be used to calculate their mass action concentrations.On the contrary,if all the binary melts are homogeneous and their activities exhibit negative deviation with respect to the Raoult‘s law.then the ternary melts formed from them will certainly be homogeneous,hence single phase model should be applied. 相似文献
12.
Jian Zhang 《北京科技大学学报(英文版)》2000,7(4):246-250
According to
phase diagrams, measured activities as well as the coexistence theory of metallic melts
structure involving compound formation, the calculating models of mass action
concentrations for Ni-Mn and Co-Mn melts are formulated and their thermodynamic parameters
are optimized. As a result, the calculated mass action concentrations agree well with the
corresponding measured activities, showing that these models can reflect the structural
characteristics of both Ni-Mn and Co-Mn melts. 相似文献
13.
Mg-Al,Sr-Al和Ba-Al熔体的作用浓度计算模型和热力学参数确定 总被引:1,自引:0,他引:1
张鉴 《包头钢铁学院学报》2001,20(3):214-218,231
根据相图、质量作用定律和金属熔体结构的共存理论制定了Mg-Al,Sr-Al和Ba-Al熔体的作用浓度计算模型并求得了相关的热力学参数,计算结果符合实际,证明所制定的模型和确定的热力学参数可以反映相应熔体的结构特点,但将相应文献的热力学参数代入同样熔体则未取得符合实际的结果,原因可能与文献中的热力学参数不符合液态下金属熔体内部化学反应的实际有关。 相似文献
14.
Thermodynamic properties and mixing thermodynamic parameters of two-phase metallic melts 总被引:1,自引:0,他引:1
JianZhang 《北京科技大学学报(英文版)》2005,12(3):213-220
Based on the calculating model of metallic melts involving eutectic, the calculating equations of mixing thermodynamic parameters for two phase metallic melts have been formulated in the light of those equations of homogeneous solutions. Irrespective as to whether the activity deviation relative to Raoultian behavior is positive or negative, or the deviation is symmetrical or unsymmetrical, the evaluated results not only agree well with experimental values, but also strictly obey the mass action law. This testifies that these equations can authentically reflect the structural reality and mixing thermodynamic characteristics of two-phase metallic melts. The calculating equations of mixing thermodynamic parameters for the model of two phase metallic melts offer two practical criteria (activity and mixing thermodynamic parameters) and one theoretical criterion (the mass action law). 相似文献
15.
Jian Zhang 《北京科技大学学报(英文版)》2003,10(1)
Based on the measured activities, the phase diagrams and the annexation principle, the calculating models of mass action concentrations for Ag-Bi and Ag-Bi-In melts have been formulated. The calculated results agree with practice and obey the mass action law, showing that the models formulated can reflect the structural characteristics of both melts. Meanwhile, it confirms that annexation principle is applicable to the Ag-Bi-In metallic melts. The melts involving eulectic which give rise to phase separation, and in which activities exhibit positive deviation from Raoult's law is the basic cause of melts transforming from homogeneous to heterogeneous ones. 相似文献
16.
Jian Zhang 《北京科技大学学报(英文版)》1999,6(3)
Based on the phase diagrams, reliable reference experimental data and the coexistence theory of metallic melts structure involving compound formation, calculating models of mass action concentrations for Fe-P and Cr-P melts have been formulated. At the same time, some of their thermodynamic parameters have been optimized. The calculated results not only agree well with the measuredvalues, but also obey the mass action law rigorously, this in turn shows that these models can reflect the structural characteristics of corresponding melts. 相似文献
17.
Jian Zhang 《北京科技大学学报(英文版)》1999,6(1)
According to the results of research on the thermodynamic propelles of Fe-Cr, Fe-P and Cr-P melts, the measured achvihes of Fe-Cr-P melts from reference sources as well as the coexistence theory of metallic melts structure involving compound formation, a calculating model of the mass action concentrations for Fe-Cr-P melts has been formulated and some of its thermodynamic parameters have been optimized. The calculated mass action concentrations agree with the measured achvities, which shows that this model can reflect the structural reality of Fe-Cr-P melts. 相似文献
18.
张鉴 《安徽工业大学学报》1997,(3)
根据含化合物金属熔体结构的共存理论、相图和Fe-C系亚稳态化合物的有关热力学数据制定了Fe-Si-C熔体的作用浓度计算模型,计算结果符合实际,从而证明所推导的计算模型可以反映本熔体的结构实际.就碳而言,就碳而言,以饱和为标准态的碳作用浓度Nc′可以通过考虑纯物质到饱和标准态的转换系数Lc来求得. 相似文献
19.
Based on the phase diagrams and the coexistence theory of metallic melts structure involving compound formation, the cal- culating models of mass action concentrations for Mn-P and Fe-Mn-P melts have been formulated. The calculated mass action concen- trations agree well with the corresponding measured activities, this in turn shows that the deduced models can reflect the structural char- acteristics of the melts concerned and there isn't any saturation of phosphorus in both melts. 相似文献