Results 211 to 220 of about 25,895 (257)
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Rare-Earth and Transuranic Elements
Physical Review, 1941Verf. zeigt das starke Absinken der Energie und das Schrumpfen der räumlichen Ausdehnung der \(4f\)- bzw. \(5f\)-Eigenfunktion beim Überschreiten der ungefähren Kernladungszahl \(Z = 57\) bzw. \(Z = 92\). Dieses Vorkommnis bedeutet, daß von diesen Ordnungszahlen ab die \(4f\)- bzw. \(5f\)-Bahnen zu inneren Elektronenbahnen werden.
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1971
Mossbauer spectroscopy of the rare-earth elements as a group has gained considerable attention from physicists. Successive addition of 4f-electrons along the series has little influence on many of the chemical properties, which are mainly those of a tripositive cation.
N. N. Greenwood, T. C. Gibb
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Mossbauer spectroscopy of the rare-earth elements as a group has gained considerable attention from physicists. Successive addition of 4f-electrons along the series has little influence on many of the chemical properties, which are mainly those of a tripositive cation.
N. N. Greenwood, T. C. Gibb
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Rare earth element geochemistry of kimberlite
Physics and Chemistry of the Earth, 1975Abstract Abundances of rare earth elements (REE), Sc, Co, Hf, Ta and Th have been determined by neutron activation analysis in kimberlites from the Wesselton pipe, in micaceous kimberlites from the Swartruggens fissure and kimberlite from the Monastery Mine, Ison Creek and Somerset Island pipes. Kimberlites are characterized by a high REE content and
ROGER H. MITCHELL, ARILD O. BRUNFELT
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Molecular Polyarsenides of the Rare‐Earth Elements
Angewandte Chemie International Edition, 2015AbstractReduction of [Cp*Fe(η5‐As5)] with [Cp′′2Sm(thf)] (Cp′′=η5‐1,3‐(tBu)2C5H3) under various conditions led to [(Cp′′2Sm)(μ,η4:η4‐As4)(Cp*Fe)] and [(Cp′′2Sm)2As7(Cp*Fe)]. Both compounds are the first polyarsenides of the rare‐earth metals. [(Cp′′2Sm)(μ,η4:η4‐As4)(Cp*Fe)] is also the first d/f‐triple decker sandwich complex with a purely inorganic ...
Arleth, Nicholas +6 more
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Biological leaching of rare earth elements
World Journal of Microbiology and Biotechnology, 2020The distinctive physico-chemical features of rare earth elements (REEs) have led to an increase in demand by the global market due to their multiple uses in industrial, medical and agricultural implementations. However, the scarcity of REEs and the harsh eco-unfriendly leaching processes from primary sources beside obliviousness to their recycling from
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Flame spectra of the rare-earth elements
Spectrochimica Acta, 1962Abstract The rare-earth elements, including scandium and yttrium, emit intense line spectra when absolute ethanol solutions of rare-earth halide or perchlorate salts are aspirated into fuel-rich, oxy-acetylene flames. Recordings of the spectra are given, along with the exact wavelengths of about 1200 of the strongest lines.
V FASSEL, R CURRY, R KNISELEY
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1987
Intermetallic phases between tungsten and rare earth elements have only been found for the W-Ce system. Two phases exist in this system, which are formed by peritectic reactions; one of them is believed to be W2Ce, “Elliott” (1965), p. 314.
Wolfgang Kurtz, Hans Vanecek
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Intermetallic phases between tungsten and rare earth elements have only been found for the W-Ce system. Two phases exist in this system, which are formed by peritectic reactions; one of them is believed to be W2Ce, “Elliott” (1965), p. 314.
Wolfgang Kurtz, Hans Vanecek
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1992
They fall into two well-defined groups, the first occurring naturally in reasonably large quantities, the second being radioactive and very largely man-made short life elements. A third group resemble the rare earths to such an extent that they are always classified together.
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They fall into two well-defined groups, the first occurring naturally in reasonably large quantities, the second being radioactive and very largely man-made short life elements. A third group resemble the rare earths to such an extent that they are always classified together.
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