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The reaction between aluminium and quinalizarin has been studied, and some modifications have been made to the analytical procedure usually followed.The absorption curve of the Al-quinalizarin compound and that of quinalizarin alone have been drawn. We applied the continuous variations method in order to determine the structure and composition of the reaction product. The spectrophotometric readings have shown that the constituents of the coloured compound are bound in a definite ratio. 2:3. 相似文献
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Nina Matoussevitch Angelika Gorschinski Wilhelm Habicht Jens Bolle Eckhard Dinjus Helmut Bönnemann Silke Behrens 《Journal of magnetism and magnetic materials》2007
Monodisperse Co nanoparticles were synthesized by thermal decomposition in the presence of aluminium alkyls yielding air-stable Co nanoparticles after surface passivation. Several procedures for surface modification of these pre-stabilized, metallic Co nanoparticles are presented, including direct anchoring of surface-active functional groups and biocompatible dextran layers as well as silica and polymer coatings. As a result, individually coated nanoparticles as well as microspheres can be obtained. 相似文献
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James C. W. Chien Phillipe L. Bres 《Journal of polymer science. Part A, Polymer chemistry》1986,24(10):2483-2505
Polymerizations of ethylene by the MgCl2/ethylbenzoate/p-cresol/AlEt3 TiCl4-AlEt3/methyl-p-toluate (CW-catalyst) have been studied. The initially formed active site concentration, [Ti] has a maximum value of 50% of total titanium at 50°C and lower values at other temperatures. The Ti decays rapidly to Ti sites with conc. ca. 10 mol %/mol Ti. The rate constants for four chain transfer processes have been obtained at 50°C: for transfer with AlEt3, k = 2.1 × 10?4 s?1 and k = 4.8 × 10?4 s?1; for transfer with monomer, k = 3.6 × 10?3 (M s)?1 and K = 8.3 × 10?3 (M s)?1; for β-hydride transfer, k = 7.2 × 10?4 s?1 and k = 4.9 × 10?4 s?1; and transfer with hydrogen, k = 4.0 × 10?3 torr1/2 s? and k = 5.1 × 10?3 torr1/2 s?1. The rate constants for the termination assisted by hydrogen is k = 1.7 (M1/2 torr1/2 S)?1. If monomer is assisting termination as was observed for propylene polymerization, then k = 7.8 (M3/2 s)?1. Values of all the rate constants can be higher or lower at other temperatures. Detailed comparisons were made with the results of propylene polymerizations. There are more than four times as many Ti active sites for ethylene polymerization than there are for stereospecific polymerization of propylene; the difference is more than a factor of two for the Ti sites. Certain rate constants are nearly the same for both monomers while others are markedly different. Some of the differences can be explained by stereoelectronic effects. 相似文献
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H. G. Von Schnering M. Baitinger U. Bolle W. Carrillo-Cabrera J. Curda Y. Grin F. Heinemann J. Llanos K. Peters A. Schmeding M. Somer 《无机化学与普通化学杂志》1997,623(7):1037-1039
The binary germanides M12Ge17 and M4Ge9 (M ? Na, K, Rb, Cs) and the stannides M12Sn17 and M4Sn9 (M ? K, Rb, Cs) were identified by a combination of direct synthesis, thermogravimetric analysis, vibrational spectroscopy, X-ray powder data and single crystal structure analysis. The M12E17 phases contain the cluster anions [E9]4? and [E4]4? in the ratio 1:2, forming a hierarchical structure with the cluster anions at the atomic positions of the hexagonal Laves phase MgZn2. Like the M4E4 phases, the M4Ge9 compounds are hierarchical derivatives of the cubic Cr3Si structure but with [Ge9]4? anions. The thermogravimetric analyses give strong evidence for the existence of at least one more phase with [E9]4? and [E4]4? clusters and of the clathrate phases M6E136 in addition to the well-known M8E44□2 chlathrates. 相似文献
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Carl Bolle 《Journal of Elasticity》2000,60(2):77-79