Neodymium electron system

Many aryl-substituted pyrylium salts are intensely fluorescent. It is possible to predict these spectral properties by a consideration of the shape of the molecule, the nature of substituents and the length of the ir-electron system (75MI22203). Pyrylium salts have been used as Q-switches for neodymium and ruby lasers in acetonitrile (68MI22200). 

Meanwhile N. Bohr was working on the theory of electron shells in atoms which also became the corner-stone of the periodic system theory and, at last, explained the periodic changes in the properties of chemical elements. Bohr also solved the problem which had interested chemists for many years he found the exact number of rare-earth elements. There had to be fifteen of them from lanthanum to lutetium. Only one REE between neodymium and samarium (later known as promethium, see p. 208) remained unknown. Bohr came to this conclusion on the basis of the laws found by him which governed the formation of electron shells of atoms with increasing Z. 

No isothermal section is available for the ternary Nd-Zn-Ge system, however one ternary compound was observed and characterized by Rossi and Ferro (1996). NdZni sGeo.s was foimd to crystallize with the AIB2 type, a = 0.4432, c = 0.3820, from X-ray powder diffraction of an induction-melted alloy which was annealed at 1070K for one week. Electronic micrographic examination as well as microprobe microanalysis was carried out. The metals employed in sample synthesis had a nominal purity of 99.9mass% for neodymium, and 99.999 mass% for the other metals. 

Light amplifiers are essential to all-optical systems (no electronic repeaters, no hght-to-electronic conversion) since they compensate for optical losses within the fibers and the associated connectors, couplers, and switches. They are achieved by doping the fiber core with fluorescent lasing ions such as erbium or neodymium, and pumping using laser diodes. 

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