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1 INTRODUCTION In recent years, ABO3-type perovskite-like manganites, RE1xDxMnO3 (RE = rare earth ions, D = Ca2+, Sr2+, Ba2+ etc.), have inspired remarkable attention due to the colossal magnetoresistance (CMR) effects for fundamental and practical consideration [1, 2]. Since A- and B-site substitution can give rise to a large number of derivant compounds, fruitful structural, magnetic and transport properties would be expected in this family. As we have known, the ideal ABO3-typ… 相似文献
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本系列文章的前五篇推导得到了用于多组分联动萃取分离流程设计的基础理论,并通过一个四组分分离流程实例介绍了该设计理论的实际应用。本文是本系列文章的最后一篇,将探讨该理论的拓展应用。所有非联动萃取多组分分离流程都可以通过适当等效变换,转换为由联动萃取流程中基本分离单元组合得到的等效流程,本文通过任意切割比例的三组分两出口分离、三组分三出口分离以及三组分联动萃取全分离等效流程等不同工艺形式实例,介绍如何通过流程的等效变换,应用本系列文章中的理论公式解决稀土工业实践中不同类型工艺流程的参数计算问题。 相似文献
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与传统流程中彼此独立的分离单元不同,联动萃取分离流程要求每一分离单元均通过横向或纵向衔接方式与其他分离单元联动运行。本系列文章之II已推导得到了无联动及出口联动(A_tA_(t-1)…A_2)/(A_(t-1)A_(t-2)…A_1)分离单元优化的基本关系式。当联动萃取流程中两个分离单元纵向衔接时,高层级分离单元提供水相/有机相料液给低层级分离单元,同时自低层级分离单元引出一个有机相/水相返回高层级分离单元作为萃取有机相/洗涤液使用,此时低层级分离单元的联动衔接位置在进料级,故可称为进料级联动。将基于对进料级联动(A_tA_(t-1)…A_2)/(A_(t-1)A_(t-2)…A_1)分离单元的萃取平衡和物料平衡分析,分别推导其料液为水相和有机相时的优化基本关系式。 相似文献
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CdS, CdS:Mn, ZnS, ZnS:Mn and ZnS:Tb nanoparticles were prepared by using carboxylic-containing copolymer, polystyrene-maleic anhydride (PSM), as template. Average particle size, 2.5 nm for CdS nanoparticles, is deduced from UV-vis absorption spectra and consistent with the observation of TEM. Characteristic emissions of the doping ions can be observed and the energy transfer from the host to the doping ions is verified. Fourier transform infrared (FTIR) spectra were studied to confirm the bonding effect of the copolymer and the metal ions. PSM hydrolyzed and chelated metal ions by its carboxylic group, and then performed as a protection layer after the formation of nanoparticles. 相似文献
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风化壳淋积型稀土矿的开采主要通过浸矿剂离子与吸附在黏土矿物表面的稀土离子发生离子交换浸出反应实现。以(NH4)2SO4为浸矿剂,采用多级逆流浸取的方式研究了风化壳淋积型稀土矿的浸矿过程,通过在逐级浸取过程中浸出液组分的变化分析了矿土中稀土离子(RE3+)和主要杂质铝离子(Al3+)的浸出行为,并基于浸矿剂的消耗规律探讨了浸矿剂离子与RE3+和Al3+的离子交换反应机制以及原矿土的净吸附量。结果表明,在浸矿液逐级浸取新鲜矿土的过程中,浸出液中的RE3+和Al3+浓度逐渐增加,铵根离子(NH4+)逐渐消耗,交换进入浸出液中的RE3+和Al3+逐级减少;同时,浸出液中的硫酸根离子(SO42-)逐级损耗,说明新鲜矿土除因发生离子交换反应消耗NH4<... 相似文献