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991.
992.
Hiroshi Harada Kanichi Kamiya Hiroyuki Nasu Jun Matsuoka 《Journal of Sol-Gel Science and Technology》1997,10(3):291-300
The sodium dititanate, Na2O·2TiO2 glass was prepared by the sol-gel method. The structure of the glass, especially local environment of Ti4+ ions was examined using X-ray diffraction and X-ray absorption fine structure (XAFS) analyses, and was compared with that of the melt-derived glass with the same composition. It was found that Ti4+ ions are rather in five-fold coordination state, forming TiO5 pyramids with one doubly bonded Ti=O in the gel-glass, while they were in lower coordination state or four-fold coordination in the melt-derived glass. 相似文献
993.
The polystyrene supported glutamic acid Schiff base complex of Mn ( Ⅱ ) (PS-Sal-Glue-Mn) was prepared with chloromethylated styrene polymer beads, 2,4-dihydroxybenzaldehyde, L-glutamic acid and manganese ( Ⅱ ) acetate tetrahyrate. The polymeric ligand and the complex were characterized by FT-IR, small area X-ray photoelectron spectroscopy (XPS) and 1CP-AES. In the presence of the manganese complex, cyclohexene (1) was effectively oxidized by molecular oxygen without reductant. The major products of the reaction were 2-cyclohexen-l-ol (2), 2-cyclohexen-l-one (3) and 2-cyclohexen-1- hydroperoxide (4), which was different with typical oxidation of cyclohexene. The influence of reaction temperature and additive for oxidation had been studied. The selectivity of 2-cyclohexen-1-hydroperoxide varied with reaction time and different additives. The mechanism of cyclohexene oxidation had also been discussed. 相似文献
994.
995.
AlkylationofBenzenewithPropeneoverHβZeolite──TheEffectofReactionConditionsontheDistributionofProductsMAJun,SHENJian-ping,SUNT... 相似文献
996.
In this paper,p-tricyanovinyl-N,N-dialkylanilines were synthesized as model compounds and through their spectroscopic behavior,the photo-induced electron transfer,charge separation were discussed and the aggregation in DMSO-H_2O system was investigated. 相似文献
997.
998.
We consider a pair of MOLS (mutually orthogonal Latin squares) having holes, corresponding to missing sub-MOLS, which are disjoint and spanning It is shown that a pair of MOLS withn holes of sizeh exist forh 2 if and only ifn 4 For SOLS (self-orthogonal Latin squares) with holes, we have the same result, with two possible exceptions SOLS with 7 or 13 holes of size 6 相似文献
999.
The phase-conjugate reflectivity obtainable by degenerate four-wave mixing in silicon at a 1.06 m is calculated including free-carrier absorption. A maximum reflectivity of more than 100% is possible. The dependence of the reflectivity on the signal and pump energy densities up to 70 mJ/cm2 is measured and found to agree with theory. The wave-front-correction property of DFWM is demonstrated with a lens in the signal beam. 相似文献
1000.