化合物TbMn6Sn6的磁性和磁相变

采用分子场理论模型对稀土-过渡族金属间化合物的磁性、自旋重取向相变和场诱导的一级磁相变进行了研究.从理论上计算了TbMn6Sn6的易磁化方向随温度的变化以及不同温度时的磁化曲线,描述了自旋重取向相变和场诱导的一级磁相变.基于单离子模型计算了Tb离子和化合物的一阶和二阶磁晶各向异性常数及其随温度的变化,得到了和实验数据基本一致的结果.结果表明:Mn次晶格和Tb次晶格磁晶各向异性能之间的相互竞争是导致自旋重取向相变的物理机制,而稀土离子的四阶晶场项对场诱导的一级磁相变产生很大的影响.     

液膜法分离富集,测定水中微量锶

用乳状液膜体系对锶进行分离富集，该体系包括协同流动载体（ＰＭＢＰ，ＴＢＰ），表面活性剂（ＳＰＡＮ８０）增强剂（丙三醇）溶剂（正己烷）和内相（１．２ｍｏｌ／Ｌ的盐酸溶液），实验表明，在适宜的条件下，锶的富集效率可达９９．５％以上，而在此条件下许多共存离子，如Ｆｅ＾３＋，Ａｌ＾３＋，Ｃａ＾２＋，Ｍｇ＾２＋，Ｂａ＾２＋，Ｃｒ＾３＋，ＣＯ＾２＋，Ｎｉ＾２＋，Ｚｒ＾４＋，Ｃｕ＾２＋，Ｚｎ＾２＋，Ｐｂ＾２＋和     

铝合金变质处理的现状和发展趋势

本文主要叙述了铝合金变质处理的方法及特点,并对铝合金变质方法的发展趋势作了展望.     

AB INITIO CALCULATION OF THE ELASTIC AND OPTICAL PROPERTIES OF Al_3Sc COMPOUND

The ab initio method has been performed to explore the elastic and optical properties of Al3Sc compound, based on a plane wave pseudopotential method. It can be seen that the calculated equilibrium lattice parameter and elastic constants are in reasonable agreement with the previous experimental data. The elastic constants satisfy the requirement for mechanical stability in the cubic structure of the Al3Sc compound. The optical property calculations show that a strong absorptive peak exists from 0-15eV and a relative small absorptive peak exists around 30eV. The form is caused by the optical transitions between high s, p, and d bands, and the latter results from the optical transitions from high s, p, and d bands to the low 2p band.     

冷镦挤复合的连接成形工艺分析及模具设计

基于镦挤连接成形的金属塑性变形规律,分析了一次连接成形件的冷镦挤复合成形的形变特点和工艺特点,进行了冷镦挤一次连接成形工艺过程的可行性分析设计和模具设计,并得到了生产实践验证。     

Zeolite based films, membranes and membrane reactors: Progress and prospects

The integration of reaction and separation in catalytic membrane reactors has received increasing attention during the past 30 years. The combination promises to deliver more compact and less capital-intensive processes with substantial savings in energy consumption. With the advent of new inorganic materials and processing techniques, there has been renewed interest in exploiting the benefits of membranes in many industrial applications. Zeolite membranes, however, have only recently been considered for catalytic membrane reactor applications. Despite the significant recent interest in these types of membranes there are relatively few reports of the application of such membranes in high-temperature catalytic membrane reactor applications. This can be attributed to a number of limitations that still need to be addressed such as the relatively high price of membrane units, the difficulty of controlling the membrane thickness, permeance, high-temperature sealing, reproducibility and the dilemma of upscaling. A number of research efforts, with some degree of success have been directed to finding solutions to the remaining challenges. This review makes a critical assessment of what has been achieved in the past few years in terms of hurdles that still stand in the way of the successful implementation of zeolite membrane reactors in industry.     

邻苯基苯酚合成工艺及应用

介绍了邻苯基苯酚的主要用途，国内外邻苯基苯酚主要的合成工艺路线及应用情况，通过对主要合成路线的比较，对今后国内的邻苯基苯酚的产业化提出合理的建议。     

气相色谱法测定有机化合物的蒸发热

本文用气相色谱测定了多种烷烃、芳烃、醇类和酯类的蒸发热。结果表明,测定数据与文献数据基本一致,误差一般在±5%以内。是一种简单、快捷的测定方法。     

Rheological evaluation of the influence of polymer concentration and molar mass distribution on the formation and performance of asymmetric gas separation membranes prepared by dry phase inversion

Asymmetric gas separation membranes were prepared by the dry-casting technique from PEEKWC, a modified amorphous glassy poly(ether ether ketone). The phase inversion process and membrane performance were correlated to the properties of the polymer and the casting solution (molar mass, polymer concentration, solution rheology and thermodynamics). It was found that a broad molar mass distribution of the polymer in the casting solution is most favourable for the formation of a highly selective membrane with a dense skin and a porous sub-layer. Thus, membranes with an effective skin thickness of less than 1 μm were obtained, exhibiting a maximum O₂/N₂ selectivity of 7.2 and a CO₂/CH₄ selectivity of 39, both significantly higher than in a corresponding thick dense PEEKWC membrane and also comparable to or higher than that of the most commonly used polymers for gas separation membranes. The CO₂ and O₂ permeance were up to 9.5×10⁻³ and 1.8×10⁻³ m³/(m² h bar) (3.5 and 0.67 GPU), respectively.     

低截留分子质量新型聚芳醚腈酮超滤膜的研制

以新型聚芳醚腈酮为膜材料 ,以N -甲基 - 2 -吡咯烷酮 (NMP)为溶剂 ,研究了聚合物浓度、添加剂种类及含量、凝胶浴温度等对超滤膜性能的影响。结果表明 ,聚合物质量分数以 1 2 %～ 1 3 %为合适的制膜浓度 ,以聚乙二醇PEG - 4 0 0为添加剂时获得了高截留率和高水通量的超滤膜。随着凝胶浴温度的升高 ,水通量明显增大 ,而截留率有所下降 ,而共聚物的浓度增加则有相反的效果。制得的超滤膜具有较低的截留分子量 (PEG- 2 0 0 0 ) ,将制得的超滤膜用于达旦黄、黄X-G等染料的分离 ,截留率均达 90 %以上