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Hace 3 días · The rare-earth elements (REE), also called the rare-earth metals or rare earths or, in context, rare-earth oxides, and sometimes the lanthanides (although scandium and yttrium, which do not belong to this series, are usually included as rare earths), are a set of 17 nearly indistinguishable lustrous silvery-white soft heavy metals. Compounds ...
Hace 4 días · Las tierras raras o Rare Earths Elements (REE, por sus siglas en inglés) son un grupo de 17 elementos químicos de la tabla periódica, 15 de ellos pertenecientes al grupo de los lantánidos. Estos minerales se clasifican según su abundancia: las livianas, en general más presentes, son el lantano, cerio, praseodimio, neodimio, prometio ...
Hace 3 días · Rare earth elements (REEs) encompass a set of 17 elements, inclusive of the lanthanide series, along with yttrium (Y) and scandium (Sc). These elements possess distinct physicochemical ...
Hace 2 días · The 1986 apparition of Halley's Comet was the least favourable on record. In February 1986, the comet and the Earth were on opposite sides of the Sun, creating the worst possible viewing circumstances for Earth observers during the previous 2,000 years. Halley's closest approach was 0.42 au.
Hace 3 días · In 1971, NASA funded a SETI study that involved Drake, Barney Oliver of Hewlett-Packard Laboratories, and others. The resulting report proposed the construction of an Earth-based radio telescope array with 1,500 dishes known as "Project Cyclops". The price tag for the Cyclops array was US$10 billion. ... However, the Rare Earth Hypothesis ...
Hace 1 día · Rare earth from a newly discovered sedimentary rare earth ore (SREO) in Guizhou Province, China, was extracted through ammonium sulfate ((NH4)2SO4) activated roasting and leaching with sulfuric acid. The phase changes and reaction mechanism during the roasting process were explored through thermodynamic analysis, XRD, thermogravimetric analysis and scanning electron microscopy. When roasted at ...
Hace 4 días · To understand how these deposits form, we recreated the hellish temperatures, pressures and chemical environments that occur kilometres below Earth’s surface, and used intense X-rays to probe the behaviour of rare earth elements down to the molecular level.
