Sm0.88Dy0.12Fe2合金的易磁化方向研究

运用穆斯堡尔效应，对Ｓｍ０．８８Ｄｙ０．１２Ｆｅ２合金的易磁化方向的变化进行了研究。结果表明；随着温度的升高，其易磁化方向从「１１０」渐变地转向「１１１」，在１５３至２１３Ｋ温度范围内，「１１０」和「１１１」两者共存，而并非由「１１０」其一温度突变至「１１１」。     

二溴对甲基偶氮磺光度法测定低合金钢中的铅含量

研究显色剂二溴对甲基偶氮磺与铅 (Ⅱ )的反应 ,建立了直接测定低合金钢中铅含量的光度分析方法。在 0 .6mol/L硝酸溶液中 ,铅 (Ⅱ )与二溴对甲基偶氮磺形成 1∶2的蓝色配合物 ,最大吸收波长为 6 30nm ,表观摩尔吸光系数为 1.2 2× 10 5L/(mol·cm) ,铅 (Ⅱ )含量在 0～ 2 .0 μg/mL范围内服从比耳定律。用该方法对合成样品中的铅含量进行测定 ,平均回收率为 10 0 %～ 10 1% ,RSD为 2 .5 %～ 4 .0 %。     

电沉积工艺对Mg-Ni储氢合金的电化学性能的影响

用电沉积的方法制备了镁 镍储氢合金,探讨了电沉积条件对合金的电化学性能的影响.XRD显示沉积层中含有非晶态Mg Ni相和微晶态Mg相.AAS分析表明沉积合金中Mg的摩尔分数达 8. 57%.合金的放电容量最高为 75. 547mA·h·g-1.     

稀土元素对Cu-6%Ag及Cu-24%Ag合金微观组织的影响

制备了Cu-6％Ag及Cu-24％Ag合金铸锭并进行了均匀化处理。通过在合金中添加0．1％混合稀土的方法，研究了稀土元素对高Ag含量和低Ag含量两种合金原始组织的影响。稀土元素可在一定程度上使共晶体数量增加，细化低Ag含量合金的铸态α基体晶粒，降低高Ag含量合金中被连续网状共晶组织包围的枝晶轴问距。在均匀化退火过程中，稀土元素可明显细化在α基体中析出的次生相，并使共晶组织更趋于分散和向离异共晶形态发展。     

含稀土抗蠕变压铸镁合金的开发

针对商用压铸镁合金抗高温蠕变性能较差的现状，开发了抗高温蠕变压铸镁合金，其开发的目的是针对大马力柴油发动机汽缸罩盖，其抗高温蠕变性能应该能够保障其在150℃条件下稳定工作，而且其成本的增加应该控制在AZ91D合金成本的15％以内。讨论了稀土元素Ce，Y，Nd及Ca和Si的添加对压铸镁合金在常温拉伸性能以150℃条件下的蠕变行为、显微组织的影响，以及对表面处理和腐蚀试验的影响，并进行了实际产品的压铸牛产。试验结果表明，所开发的抗蠕变压铸镁合金具有应用于汽车动力系统部件的制造并大幅度减轻重量的潜力。     

冶炼时添加ErCl3对AZ91镁合金组织与性能的影响

研究了冶炼AZ91镁合金时添加不同量的ErCl3对镁合金的拉伸性能、组织和断口形貌的影响。结果表明:添加ErCl3具有阻燃、净化作用,还可以提高合金的抗拉强度σb和延伸率δ。当添加ErCl3质量分数为1.8%时,σb和δ分别从156MPa和1.8%上升到最大值220MPa和4.1%,分别提高了41%和128%。随着ErCl3加入量的进一步提高,开始形成Al7ErMn5稀土相和稀土氧化物夹杂,合金的力学性能反而下降。添加ErCl3增加了二次裂纹的数量,但是不改变镁合金的断裂机制,断口形貌仍为准解理断裂。     

La修饰的Co-B非晶态催化剂用于乳酸乙酯选择性加氢制1,2-丙二醇

用化学还原法制备了La修饰的Co-B非晶态合金催化剂(Co-La-B),并考察了其在乳酸乙酯液相加氢制1,2-丙二醇(1,2-PDO)反应中的催化性能.通过X射线粉末衍射(XRD)、透射电子显微镜(TEM)、比表面积测定(BET)、差示扫描量热(DSC)、电感耦合等离子发射光谱(ICP-OES)、X射线光电子能谱(XPS)、氢气化学吸附、氢气程序升温脱附(H2-TPD)等手段对催化剂进行表征,研究了稀土助剂La对Co-B催化剂催化性能的影响.结果表明,活性组分Co以元素态和氧化态两种形式存在于Co-La-B非晶态合金催化剂中,催化剂中存在B向Co的电子转移,富电子的Co用于活化氢,氧化态形式存在的La3+促进了B向Co的电子转移;适量的La能提高催化剂的热稳定性,显著减小催化剂粒径,使催化剂形成更加单一的Co吸附活性位,有利于吸附活化的氢促进加氢反应进行.在氢气压力6 MPa,反应温度433 K,反应时间9 h的条件下,0.5%Co-La-B催化剂表现出最优的催化加氢性能,乳酸乙酯的转化率达到99.7%,1,2-丙二醇的选择性达到98.5%.     

Effects of Neodymium on the Properties of Ni‐B/CNTs Amorphous Alloy Catalyst

Neodymium is used as a promoter of Ni‐B/CNTs amorphous alloy catalyst to modify its catalytic properties. Ni‐B/CNTs and Ni‐Nd(5wt%)‐B/CNTs catalysts were prepared by the impregnation chemical reduction method. Their catalytic performances were examined in acetylene selective hydrogenation, which is a crucial step in industrial polymerization processes, with the aim of the complete elimination of alkynes from alkene feedstocks. Experiments showed that the latter exhibited higher acetylene hydrogenation activity but lower ethylene selectivity. Catalysts were characterized by ICP, CO‐chemisorption, XPS, XRD and H₂‐TPD techniques. On the basis of characterizations, the modification of Nd on Ni‐B/CNTs catalyst was related to its geometric and electronic effects.     

Quantitative surface analysis of Fe?Ni alloy films by XPS,AES and SIMS

A comparison of quantitative surface analyses of Fe? Ni alloy thin films by various methods has been proposed as a pilot study by the Surface Analysis Working Group of the Consultative Committee for Amount of Substance (CCQM). To test the suitability of Fe? Ni for this purpose, alloy films with different compositions were grown on Si(100) wafers by ion‐beam sputter deposition and the compositions were certified by an isotope dilution method using inductively coupled plasma‐mass spectrometry. The alloy compositions measured with X‐ray photoelectron spectroscopy (XPS) and Auger electron spectroscopy (AES) using sensitivity factors determined from pure Fe and Ni metal films agreed with the certified mean values to better than 2%. The alloy compositions quantified by secondary ion mass spectrometry (SIMS) with a C₆₀ ion source agreed to better than 4% with the certified compositions if one of the alloys was used to establish the relative sensitivity factors (RSFs). These results indicate that the quantification of the Fe? Ni alloy is a good method for a CCQM pilot study because matrix effects and ion‐sputtering effects are small for these analytical methods. Copyright © 2007 John Wiley & Sons, Ltd.     

Electrodeposition of Zn–Ni alloys from sulfate bath

The electrodeposition of zinc–nickel (Zn–Ni) alloys from sulfate baths has been studied at different deposition times and H₂SO₄ and NiSO₄ concentrations; various characteristics have been observed during alloy deposition and dissolution. The deposit has been investigated by using scanning electron microscopy (SEM) and X-ray diffractometry. Cyclic voltammetry and galvanostatic measurements during electrodeposition have been conducted. Electrochemical and surface analysis indicate that deposition takes place with the formation of two different structures corresponding to γ-phase and δ-phase zinc–nickel alloys. During anodic part of the cyclic voltammetry of the alloys, a reduction process has been observed, which may be due to hydrogen evolution. With the increase of nickel concentration in the bath, the amount of γ-phase increases, as indicated by the relative increase in the height of the peaks in the X-ray patterns and anodic peaks in the cyclic voltammograms. Also, the corrosion resistance of the zinc–nickel alloy has been improved with an increased concentration of nickel. Under these experimental conditions the electrodeposition of the alloys is of anomalous type.