نتایج جستجو برای: samarium
تعداد نتایج: 1033 فیلتر نتایج به سال:
Samarium-neodymium isotopic data on whole rocks and minerals of the Sudbury Complex in Canada gave an igneous crystallization age of 1840 +/- 21 x 10(6) years. The initial epsilon neodymium values for 15 whole rocks are similar to those for average upper continental crust, falling on the crustal trend of neodymium isotopic evolution as defined by shales. The rare earth element concentration pat...
Transformation of acetals into ethers by partial reduction using a samarium diiodide-Lewis acids-acetonitrile system is described. The reaction with aromatic acetals occurred in good yields in the presence of aluminum chloride (2 eq) whereas the corresponding aliphatic, vinylic, and alkynyl derivatives did not afford ethers under the same conditions. Beta-elimination to give an enol ether becom...
We report the response of the electrical conductivity of semiconducting single-walled carbon nanotube (SWNT) thin films on exposure to metal vapors of the early lanthanides under high vacuum conditions. We attribute the strongly enhanced conductivities observed on deposition of samarium and europium to charge transfer from the metals to the SWNT backbone, thereby leading to the first examples o...
The magnetoelectricity of samarium iron garnet is theoretically investigated: the antiferroelectric structures ions are described and their connection with configurations magnetic moments transformations during phase transitions revealed. possibility appearance at low temperatures unusual Bloch domain walls, in which magnetization vector rotates from [u v 0] axes to [v u axes, not crystal symme...
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