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111.
112.
A novel protocol for intramolecular ketyl-olefin radical cyclization with low-valent titanium reagent is outlined. It allows the formation of the benzopyran nucleus from ortho-allyloxy propiophenones as the sole product in moderate yields via intramolecular radical cyclization. 相似文献
113.
The present work focuses on the development of an in‐operando technique based on the visible spectroscopic reflectometry (VSR) for simultaneous determination of the oxide film formation during anodizing. The establishment of the VSR as in‐operando technique requires an extensive validation by comparative in‐situ but non‐operando thickness measurements under aqueous conditions. The investigations were carried out on anodic oxide films on pure titanium. The authors demonstrate the VSR as a simple and robust method for measurement under electrolyte covering. Additionally, an empirical correction algorithm extends the limitation of the visible reflectometry in thin film thickness. Reliable film thickness values can be measured down to ≥5 nm. The in‐operando mode yields additional information about the film growth time resolved. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
114.
Qingshan Zhang 《Journal of Dispersion Science and Technology》2013,34(1):110-114
TiO2 and Fe-doped TiO2 thin films were prepared on the substrates (glass plates and glass microballs) after dipped in colloid and calcined at 500°C. The films have been characterized by UV-absorption, x-ray diffraction and atomic force microscopy (AFM). The investigated Fe-doped TiO2 (A nominal 10 wt% Fe2O3 was impregnated) thin films were obtained by sol-gel method. The characterization results suggest that the calcined thin films primarily consist of TiO2 anatase. And the light absorption curve of the TiO2 films modified with Fe showed that red shift had happened by the dope of Fe. TiO2/beads as photocatalyst were used to degrade the simulated dyeing water which contains reactive deep-blue dye (K-R). Through the degradation experiment, we found that the dope of Fe promoted the photocatalytic activities. The results showed that the dyeing water can be decomposed more effectively by the photocatalytic oxidation of Fe/TiO2 film on glass micro-balls than glass plates. 相似文献
115.
铁铈复合氧化物催化剂SCR脱硝的改性研究 总被引:1,自引:0,他引:1
利用共沉淀法制备了铁铈催化剂,考察添加钛、锆、钨和钼对其SCR脱硝的改性规律。结果表明,钨和钼的添加提高了铁铈催化剂高温脱硝性能,却使其低温活性有所降低;钛的添加对铁铈催化剂脱硝性能具有促进作用,尤其提高了其低温活性,并拓宽了其完全转化温度窗口,为最佳改性物。当钛的物质的量比逐渐由0.10增至0.40,铁铈钛催化剂低温脱硝效率先增大后减小,但其高温脱硝效率逐渐增大至100%,钛的最佳物质的量比为0.15。XRD和N2吸附分析结果表明,钛能优化铁铈催化剂的孔隙结构,增大其比表面积和比孔容,细化其孔径,并与催化剂中铁、铈氧化物形成良好的固溶体,从而提高了铁铈催化剂的SCR脱硝性能。Fe0.8Ce0.05Ti0.15Oz催化剂在150~400℃取得了高于90%的NOx转化率。 相似文献
116.
Mohammad Hayatifar Claudia Forte Guido Pampaloni Yury V. Kissin Anna Maria Raspolli Galletti Stefano Zacchini 《Journal of polymer science. Part A, Polymer chemistry》2013,51(19):4095-4102
This report describes propylene polymerization reactions with titanium complexes bearing carbamato ligands, Ti(O2CNMe2)Cl2 ( I ) and Ti(O2CR2)4 [R2 = NMe2 ( II ), NEt2 ( III ) and ( IV )]. Combinations of these complexes and MAO form catalysts for the synthesis of atactic polypropylene, as confirmed by FT‐IR, DSC and 13C NMR analysis. Effects of main reaction parameters on the catalyst activity were studied including the type of complex, solvent, temperature, and the [Al]/[Ti] molar ratio. The highest activity was observed when chlorobenzene was used as a solvent and AlMe3‐depleted MAO was employed as a cocatalyst. © 2013 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2013 , 51, 4095–4102 相似文献
117.
Dr. Yang Chen Dr. Elzbieta Trzop Jesse D. Sokolow Prof. Dr. Philip Coppens 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(49):16651-16655
The structures of three newly synthesized phosphonate‐substituted polyoxotitanates are reported. The Ti/O core of [Ti4O(OEt)12(PhenylPO3)] ( 1 ) is the building block for two larger phosphonate‐substituted nanoclusters, [Ti25O26(OEt)36(PhenylPO3)6] ( 2 ) and [Ti26O26(OEt)39(PhenylPO3)6]Br ( 3 ). All compounds exhibit a not previously recognized triply bridging binding mode of the phosphonate anchor with short connecting Ti? O bonds, the average of which is 2.010(7) Å. Comparison with previously reported work suggests that the binding mode of the phosphonate anchor is strongly dependent on the structure of the underlying substrate. 相似文献
118.
本文首次通过pH值控制沉淀法制备前驱物丁二酸钛肼复盐,并进一步热分解制备大比表面积钛黑颜料-黑色钛氧化物。通过比表面积(BET)、电子能谱(EDS)、X射线光电子能谱分析(XPS)、X射线粉末衍射(XRD)、场发射扫描电子显微镜(HRSEM)、物理吸附仪、激光粒度仪和Color i5型台式分光测色仪对黑色钛氧化物进行了表征,确定了黑色钛氧化物的组成为2TiO2·Ti2O3,其表面积为53.854 4 m2·g-1。并考察了酸源、水合肼用量、酸钛比、反应时间、pH、NaOH浓度和煅烧温度等各种反应参数对黑色钛氧化物的颗粒尺寸、分布均匀性和黑色度的影响。用元素分析仪和等离子体光谱仪测定了前驱物组成,确定其组成为[Ti(C4H4O4)2]0.85·2Ti2O3·6N2H4·3H2O,并探讨了黑色钛氧化物形成机理,为新型混合价材料黑色钛氧化物的制备提供重要参考依据。 相似文献
119.
The brief review of industrial technologies of titanium-containing concentrates processing has been carried out. Drawbacks of the existing titanium manufacture schemes are shown and the necessity of the essentially new fluoride technologies development has been proved. The reactions proceeding during the fluorination of rutile concentrate with element fluoride are described in the given work. The thermodynamic research of the process has been carried using ASTRA software. Dependence of mass concentration change of titanium tetrafluoride has been investigated in products of reaction on the temperature of the process, and the choice of optimum excess of fluoride has been proved. 相似文献
120.
Jingyi Kang Na Chang Feifei Wang Haixia Liu Xuemei Wang Xinzhen Du 《Journal of separation science》2022,45(6):1273-1281
A novel solid-phase microextraction coating of phosphorous-containing titanium oxide composite was developed using titanium fiber as a support and a titanium source by hydrothermal oxidation in a phosphoric acid solution containing hydrogen peroxide. The morphology of the fiber coatings was controlled by the conditions of the hydrothermal oxidation reaction. The oriented nanofiber coating was employed to extract several types of representative aromatic analytes. The experimental results demonstrated that the as-prepared fiber exhibited excellent extraction efficiency toward polycyclic aromatic hydrocarbons. Combined with high-performance liquid chromatography with ultraviolet detection, main extraction conditions were optimized, including pH, ionic strength, extraction temperature, stirring rate, extraction time and desorption time. The established method presented good linearity from 0.05 to 200 μg/L with limit of detection ranging from 0.012 to 0.126 μg/L. This convenient and green procedure was suitable for the selective extraction and determination of typical polycyclic aromatic hydrocarbons in environmental water samples. The relative recoveries of 85.8–112% were obtained for the determination of target polycyclic aromatic hydrocarbons in water samples spiked with 5.0 and 15.0 μg/L. Moreover, the as-prepared fiber showed at least 210 extraction/desorption cycles due to its high mechanical and chemical stability. 相似文献