铱与溴化亚锡和2-巯基苯并噻唑的显色反应——萃取光度法测定微量铱

2-巯基苯并噻唑(MBT)作为铱的沉淀剂早已用于铱的重量法测定,用于铂族金属的萃取分离已早有报导。Dlamantatos用氯仿萃取铑与氯化亚锡和MBT的反应物使铑、依分离,获得了满意的结果。水相中的铱在加热煮沸下与MBT反应,萃入有机相,破坏萃取物,用溴化亚锡测定,操作冗长也不易掌握。实验发现,溴化亚锡和MBT在加热煮沸下能与铱生成稳定的浅黄色络合物沉淀,并易     

贵金属冶金物料中微量钯,铂,铑的双波长分光光度法同量测定的研究

本文提出了用二苄基二硫代乙二酰胺（ＤｂＤＯ）为显色剂分光光度测定铑的方法，并进一步研究了该试剂与钯、铂的反应，从而建立了可在一个试样中同时测定该三元素的方法。在２～３ｍｏｌ／Ｌ ＨＣｌ溶液中，钯与ＤｂＤＯ在室温显色，用氯仿萃取并用８．４ｍｏｌ／Ｌ ＨＣｌ振荡有机相，然后在４５４ｎｍ测定。在萃余液中加入ＳｎＣｌ２，并在沸水浴中加热，使铂、铑的ＤｂＤＯ络合物生成，再用氯仿萃取，８．４ｍｏｌ／Ｌ ＨＣｌ     

高自旋极化氧化物材料的颗粒边界磁电阻效应

颗粒边界磁电阻是高自旋极化氧化物颗粒体系中由于颗粒边界的存在而导致显著的磁电阻效应。本文将这种磁电阻效应定义为颗粒边界磁电阻效应。这里所说的颗粒边界,包括各种自然和人工晶界、粉末颗粒表面、复合材料中的颗粒界面等多种情况;所涉及的材料包括高自旋极化氧化物多晶、压缩粉末和各种复合材料等。对颗粒边界磁电阻效应的研究,不仅有助于人们进一步理解高自旋极化氧化物磁输运性质的基本机制,并为寻求具有高磁电阻效应的新型自旋电子学器件提供理论基础。本文综述了高自旋极化氧化物颗粒边界磁电阻研究的主要背景和发展现状,介绍了该领域中主要的实验发现和理论模型,展望了未来的发展。     

二元无规混合系统的有效介质理论

本文从二元无规混合物的两种不同拓扑结构出发,在Maxwell-Garnett理论的基础上,提出一种自洽的方法以改进类平均场的Bruggeman有效介质理论。导出了二元无规混合物有效电导率的普适式,研究了一些实际材料的电导率和热导率问题,理论计算结果与实验数据符合甚好。 关键词：     

横场伊辛铁磁薄膜的自旋波

本文在格林函数理论的框架内,研究横场伊辛铁磁薄膜系统的自旋波,分析了横场、表面特性等薄膜参数对自旋波频谱及谱强度分布的影响,证实在一定的参数条件下可以出现一致进动模和局域的表面模。 关键词：     

The effects of current-path patterns on magnetotransport in spatially-confined structures by Monte Carlo simulation

Simulations are performed on clusters of finite size to study the effects of size and current-path structure on magnetotransport in spatially-confined samples. Magnetotransport networks are established and calculated based on fractal structures including Koch curves and percolation backbones extracted from regular lattices. The structure pattern of clusters is shown to play an important role in the magnetotransport behaviours by affecting the magnetoresistance fluctuations due to spin disorder in the systems of small size, which suggests the possibility of controlling the magnetotransport by the design of current-path configurations.     

Random matrices applied to superconductivity in nano-particles

In this paper we introduce an approach in which the random matrices are applied to superconducting nano-particles, and obtain the effects of enhancement and attenuation simultaneously. We also explore the influence of magnetic fields on the superconductivity and the condensation energies in nano-particles. Comparisons with other models and some experimental results are given.     

半无限伊辛铁磁系统表面磁性的研究

本文应用平均物重整化群方法对于具有非晶化表面的半无限伊辛铁磁系统,在有表面无规场存在的情形,其表面磁性的临界性质包括临界温度、三临界点以及重入现象的可能性作了详细的研讨。 关键词：     

高活化铝合金牺牲阳极材料的研制

通过添加锌、铟、锡、镓等合金元素和适当的冶炼工艺，研制成功了工作电位负于－１．４０Ｖ（ＳＣＥ）、实际电容量≥２１７５Ａ．ｈ／ｋｇ、表面活性高、溶解非常均匀的铝合金牺牲阳极、该铝合金牺牲阳极在海水、淡海水介质中具有优异的电化学性能，可全面替代镁合金牺牲阳极、具有较高的技术经济优势。     

EFFECTS OF LONG-RANGE INTERACTIONS ON THE FERROELECTRIC FILM

The effect of long-range interactions on the spontaneous polarization and the Curie temperature of the ferroelectric film is investigated by use of the Landau theory. On the assumption that the nearest-neighbour interaction remains constant, we find that the spontaneous polarization and the phase transition temperature increase with the enhancement of the long-range interactions. In the case of positive extrapolation length, the critical thickness of the ferroelectric film, in which a size-driven phase transition occurs, decreases with the enhancement of the long-range interactions.