منابع مشابه
Extractive metallurgy of rare earths
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...
متن کاملRare Earths Crucial Elements of Advanced Technologies
Aldrich brand products are sold through Sigma-Aldrich, Inc. Sigma-Aldrich, Inc. warrants that its products conform to the information contained in this and other Sigma-Aldrich publications. Purchaser must determine the suitability of the product for its particular use. See reverse side of invoice or packing slip for additional terms and conditions of sale. All prices are subject to change witho...
متن کاملCIAC comprehensive information system of rare earths
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...
متن کاملThe resistivity of liquid rare earths
The resistivities of various liquid rare earths were calculated in a single-site t-matrix approximation. Good agreement with experiment is achieved. Spin disorder scattering is shown to be unimportant in the liquid state. The experimental resistivity data of liquid rare earths (RE) shows the following behavior [l, 21 : The resistivity p increases across the series of the trivalent RE's. The tem...
متن کاملEarths: Rare in Time, Not Space?
We compare two recent astrobiological approaches to the solution of the problem of the “Great Silence” (or Fermi’s paradox): the “rare Earth” hypothesis of Ward and Brownlee, and the phase-transition scenario of Annis. We show that they have important similarities, as far as self-selection of intelligent observers is concerned. In order to better illuminate the differences, we consider the dura...
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ژورنال
عنوان ژورنال: Tetsu-to-Hagane
سال: 1984
ISSN: 0021-1575,1883-2954
DOI: 10.2355/tetsutohagane1955.70.11_1523