熔盐电沉积稀土金属及其合金的研究：中山大学电化学研究工作介绍

熔盐电沉积稀土金属及其合金的研究——中山大学电化学研究工作介绍①杨绮琴（中山大学化学与化学工程学院广州５１０２７５）稀土金属及其合金具有许多优异的特殊性能，在国民经济中的应用日益广泛，是发展现代高新科学技术不可缺少的材料，例如磁性、磁光、超导、贮氢、...     

自组织人工神经网络在氟化物非晶态形成的判别条件中的应用

本文运用Ｔ．Ｋｏｈｏｎｅｎ自组织人工神经网络，利用化学健参数法，研究了三元系氟化物非晶态形成的判别条件，建立了相应的计算法判别智能软件．识别成功率较高．结果表明，该方法性能良好，可望成为研究化合物非晶态形成条件的有效的辅助手段．     

TiAl-RE合金中稀土相的形成机理

在TiAl合金中加入以Ce和La为主要元素的混合稀土得到普通铸态和熔体旋淬法试样，稀土元素金属间化合物AlCe(AlLa)分别存在于晶粒边界和层片结构之上。本文基于对二元合金平衡相图的分析以及应用Miedema 生成热模型对稀土相AlCe(AlLa）的形成进行了分析。结果表明，Al元素与Ce和La的亲和力远大于其与Ti之间的亲和力。因此，TiAl基合金中的富稀土相似AlCe(或AlLa)的形成存在，是必然的结果。     

水溶液中制备Ni-P-B超细非晶合金微粒的化学反应

研究了新型Ni-P-B超细非晶合金(UFAAP)的制备化学反应。Ni-P-B UFAAP通过在溶液中使用KBH₄和NaH₂PO₂还原NiCl₂生成，反应较复杂，涉及6个基本化学方程式。通过监控反应pH随时间的变化，发现总反应分成4个阶段，其中Ⅱ、Ⅲ阶段分别生成Ni-P-B和Ni-B UFAAP。在第Ⅱ阶段收集样品可得Ni-P-B。随着反应物比例n(H₂PO₂)/n(Ni²⁺)的增加，产物中的磷含量增加。此外，还考察了反应物溶液滴加方式和滴加速度对反应过程和产物组成的影响。     

X-荧光光谱法测定硅铝钡合金中硅铝钡

硅铝钡合金是炼钢常用的脱氧剂 ,主要成分为硅、铝、钡、铁。目前常用的分析方法为化学法 ,分析时间长 ,而且操作繁琐。为此 ,本法对X 荧光光谱粉末压片法进行了研究 ,结果满意 ,而且分析速度快 ,操作简便。1　试验部分1.1　主要仪器与测定条件瑞士产ARL980 0型XRF XRD结合式光谱仪 ,铑钯端窗式X射线管 ;奔腾ⅡWIN 98计算机。日本产MP 5 0型压片机 ,最大压力为 5 0t。仪器测定条件见表 1。表 1　仪器测定条件Tab .1　Workingconditionoftheinstrument分析线Analyticalspectralline晶体Crystal探测器Detector管压Tubepressure(U/kV…     

原子簇NixFe和NiFex(x=1-5)电子性质的DFT研究

More than one hundred models were designed to reflect the local structure and electronic property of Ni-Fe amorphous alloys. After calculating by DFF method, a series of configurations of clusters NixFe and NiFex （x = 1 - 5） were gained. The configurations, which possessed the lowest energies and non-imaginary frequencies, were considered the most stable optimized structures. The catalytic activity, charge and magnetic properties were analyzed and discussed. The different Fe content changed the catalytic properties of clusters through altering the value of Fermi level of every cluster. However the density of state （DOS） nearby Fermi level and average 3d orbital population of atom Ni, which were also important properties related to the catalytic activation, were little changed. Based on the Fermi level, the activity of catalyst toward hydrogenation reaction would be considered best when the ratio of Ni to Fe was close to 1. The Fermi level of clusters was far distant to the level of nitrogen in singlet state. It would be the reason why the reaction condition in ammonia synthesis and nitrogen fixation process was rigorous. When Fe atom contents were higher than 75% （NiFe3）, the electrons transferred from atom Fe to Ni, but when the ratio was decreased, the transfer was reversed. The ratio of atoms of local structure also played an important role in the aspect of electron transition. On the average 3d orbital population of atom Fe, the average magnetic moments of Fe atoms in clusters were calculated. When Fe atom contents were 50% nearly, the average magnetic moment achieved the highest point.     

ICP-AES测定钼铁中微量锑和锡

讨论了CID作检测器，ICP－AES测定钼铁中微量锑和锡，选择了最佳分析谱线和仪器重要参数，通过试验大量钼和铁的影响，用铁量匹配绘制校准曲线对试样进行直接测定的方法，检出限锑为0．0011％，锡为0．0004％，回收率为99％－103％。     

复合型扫描微pH电极及其在局部腐蚀中的应用

研制了一种新型的微米级复合型扫描pH探针.该探针具有体积小、响应速度快、稳定性好和制作方便等优点，能很好地满足微区pH快速测定的要求.应用复合型扫描微pH电极技术研究了Al/Cu合金在0.01 mol•L－1 NaCl溶液中开路状态下局部腐蚀发生的早期过程.     

Preparation of Uniform Ni-B Amorphous Alloy Catalyst on CNTs and its Performance for Acetylene Selective Hydrogenation

Carbon nanotubes (CNTs) are severely bundled and essentially insoluble in solvent. These properties are generally considered as a significant barrier toward the practical uses of CNTs. Therefore, the functionalization and solubilization of CNTs have recei…     

铈降低在硫酸溶液中生长的阳极Pb(II)氧化物膜的电阻的研究

应用电化学阻抗频谱法、线性电位扫描法和光电流技术研究了在4.5 mol· dm~(-3) H_2SO_4溶液中Pb-1%(at.)Ce（简称Pb-1Ce）合金在0.9 V (vs. Hg/Hg_2SO_4电极)生长的阳极Pb(II)氧化物膜的电阻较纯铅的低的原因。实验结 果表明，Ce阻抑阳极Pb(II)氧化物膜的生长并增加其孔率，从而降低其电阻。