نتایج جستجو برای: Rare-earths

تعداد نتایج: 241550  

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه شهید بهشتی - دانشکده علوم 1372

a simple, sensitive and selective method for solvent extraction and spectrophotemetric determination of lanthanum (ii) europium (iii), and cerium (iii) is described , the rare earth metals are extracted into chloroform solution of n-phenylbenzohydroxamic acid (pbha) at ph 9-10 various parameters are studied to optimize the extraction conditions. the molar absorptivity is found to increase from ...

Journal: :analytical and bioanalytical chemistry research 2015
yasaman heidari mahdieh koorepazan moftakhar abbasali zamani mohammad reza yaftian

the present work concerns on the investigation of the role of polyethylene glycols (pegs) as masking agent for amelioration of extraction-separation of la(iii), eu(iii) and er(iii) ions by the acidic extractant bis(2-ethylhexyl)phosphoric acid (dehpa). the studied solvent extraction system is based on the combination of chelating effect of dehpa in the organic phase on the one hand, and the bin...

2016
Jianping Ge Yalin Lei Lianrong Zhao

The supply of rare earths in China has been the focus of significant attention in recent years. Due to changes in regulatory policies and the development of strategic emerging industries, it is critical to investigate the scenario of rare earth supplies in 2025. To address this question, this paper constructed a dynamic computable equilibrium (DCGE) model to forecast the production, domestic su...

Journal: :Journal of Chemical Information and Computer Sciences 1991
Lu Xu Guoquan Li Shuyun Wang Hong Lu Huayun Wang Chang-Yu Hu Xuhong Jiang Yonghui Xiao Yunde Xiao Xiangyu Lu

The CIAC (Changchun Institute of Applied Chemistry) Comprehensive Information System of Rare Earths is composed of three subsystems, namely, extraction data, physicochemical properties, and reference data. This paper describes the databases pertaining to the extraction of rare earths and their physicochemical properties and discusses the relationships between data retrieval and optimization and...

2017
Shane Bilsborough

Drawing on literature in China studies, strategic theory, and expert interviews, this article analyzes the possibility of "rare earths" being leveraged by the People's Republic of China (PRC) in a crisis. The evidence suggests China's position in the rare earths market could constitute a significant security liability for the United States. It also seems that even if coercion fails to materiali...

Journal: :Science 1916

2013
Alok Rout

It is shown that rare earths can be distributed between two immiscible ionic liquids, allowing the transfer of the rare earths from one ionic liquid phase to another. The ionic liquid 1-ethyl-3-methylimidazolium chloride was used as the initial feed phase and the ionic liquid trihexyl(tetradecyl)phosphonium bis(2,4,4trimethylpentyl)phosphinate (Cyphos IL 104) as the extracting phase. The rare e...

Journal: :Tetsu-to-Hagane 1984

2013
F. Habashi

Although most of the rare earth metals were discovered in Sweden, the industrialisation started in the Austrian Empire. This was due to the fact that the Swedish chemist Jons Fridrik Bahr (1815–1875) from Uppsala went to Heidelberg in Germany in 1855 to analyse some rare earth minerals by the spectroscope discovered recently by chemistry professor Robert Bunsen (1811– 1899) and his colleague ph...

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