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The solvent extraction of La3 from hydrochloric acid solutions was investigated using bis (2, 4, 4-trimethylpentyl) monothiophosphinic acid (Cyanex 302, HL) as an extractant. The effect of .equilibrium of aqueous acidity on extraction of La^3 using Cyanex 302 in different diluents was discussed. The effects of extractant concentration and chloride ion on the extraction reaction were also studied. Stoichiometry of the extraction reactions and the nature of metal complexes formed were determined using slope analysis technique and IR measurement. 相似文献
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核磁共振波谱是化合物结构分析的强有力的工具。然而谱线的重叠严重地影响了官能团的辨认,从而不能精确地测定化合物的结构。为了解决这一问题,固然可以研制分辨率更高的仪器,但其代价是高昂的。而其 相似文献
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The mechanism of thermal decomposition of rare earth acetate hydrates(Ln(Ac)_3·nH_2O,n=5,forLn=La;n=4,for Ln=Pr→Lu,Y,except Pm)has been studied by TG-DTG,DSC,infrared spectra,X-raydiffraction and chemical analysis.The thermal decomposition reaction consists of two stages,one is dehydrationand the other one is decompostion.The final product is oxide.It has been found that the temperature of pro-ducing anhydrous acetates decreases with increasing atomic number of rare earth elements.The activation ener-gies for dehydration and decomposition reaction of rare earth acetate hydrates have been calculated byFreeman-Carroll and Kissinger method.The dependence of activation energy Jor dehydration reaction on theatomic number of rare earth elements shows“inclined‘W’effect”.The enthalpy changes for dehydration anddecomposition reaction have been determined. 相似文献
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一、前言 离子交换色谱在许多领域都得到了广泛的应用。但它的最大缺点是分离速度慢,分离时间往往长达几十个小时。怎样提高其分离速度,多年来一直是色谱工作者研究的重要课题。六十年代中期出现了高压离子交换色谱,它是在经典离子交换色谱基础上发展起来的一个新的分离分析技术,从而使古老的离子交换色谱面目为之一新。由于高压离子交换色谱具有快速、高效、操作简便等特点,因而它的发展很迅速,目前已经广泛地应用于许多领域,在许多性质相似或成份复杂的样品的分离分析上发挥了令人瞩目的作用。 相似文献
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In this paper the stability constants and thermodynamic parameters for complexes of rare earth elementswith L-threonine have been measured systematically by potentiometry and calorimetry at 25℃ and ionicstrength of 0.15 mol/L(NaCl).The thermodynamic values for protonation of the anion of L-threonine havebeen obtained.The dependence of stability,enthalpy and entropy change of the complex upon atomic number ofcation is investigated,and the coordination of L-threonine to rare earth is also discussed in detail. 相似文献
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