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71.
72.
Fe(OH)2悬浮液在EDTA作用下氧气氧化生成δ-FeOOH的机理研究 总被引:1,自引:0,他引:1
At room temperature and in the presence of trace EDTA, the formation of δ-FeOOH was studied by the rapid oxidation of Fe(OH)2 suspension with O2. The structural and morphological changes were characterized by various techniques such as XRD, FTIR and TEM. γ-FeOOH and (δ-FeOOH) formed simutaneously in the early period of oxidation. But as the rate of mass transfer was in equilibrium, trace (γ-FeOOH) vanished gradually. Accordingly, pure phase δ-FeOOH was obtained. At the same time, critical amount ratio K of EDTA to Fe2+ was verified. The experiments show that the reactivity, rate of the oxidizing agent and pH of the initial medium were important factors for the formation of pure phase (δ-FeOOH). Under the auxiliary effect of EDTA, the reactivity of O2 was nearly improved to that of H2O2. And the process of the oxidation that Fe(OH)2 suspension was oxidized by O2 under that condition was discussed. 相似文献
73.
Hiromi Hamamoto 《Tetrahedron letters》2004,45(11):2293-2295
The direct aromatic carbon-oxygen bond-formation reaction was described and the novel and simple synthetic method for chroman derivatives involving aromatic cation radical intermediates was developed using the hypervalent iodine(III) reagent, phenyliodine(III) bis(trifluoroacetate) (PIFA). 相似文献
74.
Subbarayan Velusamy 《Tetrahedron letters》2005,46(22):3819-3822
Copper(II) complex 1 catalyzes the oxidation of sulfides to sulfoxides with 30% H2O2 in high yields. Addition of a catalytic amount of TEMPO to the reaction mixture enhances the conversion and selectivity. Complex 1 can be recycled without loss of activity. 相似文献
75.
相转移催化应用于催化裂化汽油氧化脱硫的研究 总被引:11,自引:0,他引:11
随着人们环境保护意识的增强及原油硫含量的增大, 生产满足环境保护要求的清洁燃料是全球炼油工业的发展趋势, 燃料油脱硫显得越来越重要. 在众多的脱硫方法中, 选择性氧化脱硫技术以其工艺条件温和, 脱硫效果明显等特点, 受到了炼油行业的极大关注[1~3], 但脱硫率偏低(30%), 其关键是水相氧化剂与含硫化合物的有效混合. 本文将相转移催化应用于催化裂化(FCC)汽油的氧化脱硫中, 并对脱硫的工艺和机理进行了研究. 相似文献
76.
H. Flyger J. Fenger E. Lund Thomsen E. Lewin S. E. Gryning E. Lyck 《Fresenius' Journal of Analytical Chemistry》1976,282(4):297-300
Summary Pertinent, previous studies of the oxidation of SO2 in the atmosphere are briefly reviewed. A project dealing with the conversion in the plume from an oil-fired power station is described in greater detail. Measurements were performed from an aircraft and included continuous registration of NOx, SO2 and ozone concentrations. The possibility of using NOx as an internal tracer is discussed; also the use of the inert tracer SF6 is treated and a special detector for the continuous registration of SF6 in relative concentrations down to 10–6 ppm is described. Preliminary results indicate a half-life for SO2 in the plume of about half an hour.
Umsetzung von Schwefeldioxid in der Atmosphäre
Zusammenfassung Einschlägige frühere Studien über die Oxidation von SO2 in der Atmosphäre werden kurz diskutiert. Ein Projekt zum Studium der Umwandlung im Abrauch eines ölbefeuerten Kraftwerkes wird im Detail beschrieben. Die Messungen wurden mit Hilfe eines Flugzeuges vorgenommen und schließen die kontinuierliche Aufzeichnung von NOx-, SO2- und Ozon-Konzentrationen ein. Die Möglichkeit der Verwendung von NOx als interner Indicator wird diskutiert. Außerdem wird der Gebrauch des inerten Indicators SF6 behandelt und ein spezieller Detektor für die kontinuierliche Aufzeichnung von SF6 mit relativen Konzentrationen bis herunter auf 10–6 ppm beschrieben. Vorläufige Ergebnisse deuten auf eine Halbwertszeit von SO2 im Abrauch von etwa 30 min hin.
Presented at the 6th Annual Symposium on Recent Advances in the Analytical Chemistry of Pollutants, April 21–23, 1976; Vienna, Austria 相似文献
77.
Jean-Claude Jacquesy 《Journal of fluorine chemistry》2006,127(11):1484-1487
This is a summary of a lecture presented at the 100th Anniversary, Moissan Symposium in Paris on Friday 10th November 2006.In HF/SbF5, Vinca alkaloids react selectively at the D’ring of the molecule. In the presence of CHCl3 (or CCl4), vinorelbine yields 20′,20′-difluoro-3′,4′-dihydrovinorelbine (vinflunine), presently in phase III experimentation for treatment of bladder cancer and non small cell lung cancer. 相似文献
78.
Masato Nanjo 《Journal of organometallic chemistry》2005,690(12):2952-2955
Bis(triphenylgermyl)zinc (Ph3Ge)2Zn (1), prepared by the reaction of diethylzinc (Et2Zn) with two molar amounts of triphenylgermane (Ph3GeH), was easily reacted by a small amount of oxygen to give tetrameric oxide (Ph3GeZnO)4 (2). Four zinc and four oxygen atoms in 2 are arranged such that a cube is formed as determined by X-ray diffraction analysis. Further oxidation of 2 led to the formation of digermoxane, (Ph3Ge)2O as a final product. 相似文献
79.
Stefan G Ebbinghaus 《Journal of solid state chemistry》2004,177(3):817-823
Single crystals of the new compound La1.2Sr2.4RuO7, an oxide related to the hexagonal perovskites, were grown from a BaCl2 flux. The structure was solved by single crystal X-ray diffraction. La1.2Sr2.4RuO7 crystallizes in the space group with a=5.760(1) Å and c=18.273(3) Å. It is one of the rare examples of oxides with isolated RuO6-octahedra. The structure consists of alternating layers of RuO6-octahedra and trigonal (La,Sr)O6-prisms. These prisms are capped by one additional oxygen ion, which occupies a distorted position within the (La,Sr)O6-layers. La1.2Sr2.4RuO7 is the second member of the general [A2O][AnBn−1O3n] family of hexagonal perovskites with n=2 and the first ruthenate possessing this structure. XANES investigations, bond valence sum calculations and magnetic measurements show that ruthenium takes the oxidation state +5. Although the ruthenium ions have quite long distances, a medium strong antiferromagnetic interaction between these paramagnetic centers was observed. 相似文献
80.
1,3,5-Trihydroxyisocyanuric acid (THICA), which serves as an efficient radical-producing catalyst from hydrocarbons, was successfully prepared by two methods. The reaction of O-benzylhydroxyamine with phenyl chloroformate gave formbenzyloxycarbamic acid phenyl ester of which subsequent treatment with dimethylaminopyridine (DMAP) produced 1,3,5-tribenzyloxyisocyanurate leading to THICA by hydrogenation with H2 on Pd/C. The other method involved the direct synthesis of 1,3,5-tribenzyloxyisocyanurate from O-benzylhydroxyamine and diphenyl carbonate. The aerobic oxidation of p-methylanisole catalyzed using THICA as a key catalyst afforded p-anisic acid in almost quantitative yield (>99%). 相似文献