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41.
Pd catalysts supported on TiO2, ZrO2, ZSM-5, MCM-41 and activated carbon were used in catalytic wet oxidation of hydrocarbons such as phenol, m-cresol and m-xylene.
It was found that the Pd/TiO2 catalyst was highly effective in the wet oxidation of hydrocarbon. The activities of catalysts with various hydrocarbon species,
catalyst support, oxidation state of catalyst performed in a 3-phase slurry reactor show that reaction on Pd surface is more
favorable than that in aqueous phase and that the active site is oxidized Pd in catalytic wet air oxidation of hydrocarbons.
Based on the experimental results, a plausible reaction mechanism of wet oxidation of hydrocarbons catalyzed over Pd/TiO2 catalyst was proposed. This catalyst is superior to other oxide catalysts because it suppressed the formation of hardly-degradable
organic intermediates and polymer. 相似文献
42.
Kazuyuki Tsubone Noriko Uchida Kunio Mimura 《Journal of the American Oil Chemists' Society》1990,67(7):451-454
A series of new amphoteric surfactants having a phosphoric acid group, a tertiary amino group and a 2-hydroxyalkyl group, sodium 2-(N-2-hydroxyalkyl-N-methyl-amino)ethyl hydrogen phosphates (alkyl: n-tetradecyl, n-hexadecyl, n-octadecyl), were prepared by an addition reaction of 1,2-epoxyalkanes to N-methylaminoethanol, followed by the introduction of a phosphoric acid group and neutralization with sodium hydroxide. The structures of these compounds were confirmed by spectroscopy and elemental analysis. The solubility in solvents, Krafft point, surface tension, critical micelle concentration (CMC), occupation area of the molecule at the surface of aqueous solutions and foaming power were measured. It was shown that a 2-hydroxyethyl group in a long alkyl chain seemed to behave as a hydrophobic part. 相似文献
43.
冷却塔的冷却效果主要由淋水填料的冷却数和冷却塔的有效高度决定,淋水填料的换热性能决定了冷却塔的主要换热效果。为提高抗震冷却塔的抗震效果,淋水填料采用金属填料。通过在某工程中抗震冷却塔金属填料与普通塑料填料应用的对比分析,研究金属填料的特点及适用性,为抗震冷却塔的设计提供依据。 相似文献
44.
This work investigates the electric field effect on nitrogen oxide (NO) pollutant formation and emission composition of premixed flames in order to provide better insight on the mechanism of controlling the combustion process by electro-physical means. The present study aims to investigate experimentally the effect of radial DC electric field on premixed laminar methane flame. The electric field effect on flame shape, emission composition and NO emission index of flame is investigated experimentally under the action of direct-current electric field under varying equivalence ratio and level of oxygen enrichment. The results show that ionic wind effects cause the distortion in flame shape. The ionic wind effects diminish with increasing flow rate and level of oxygen enrichment. Minimal effects on NO are measured for flames under the influence of electric field and vanished as the level of oxygen enrichment is increased. This was well supported by the temperature profile measurement in the post flame gas showing no field-induced modification also. It seemed that the action of an electric field on a flame with a geometry that remains practically undeformed produces very minimal effect on pollutant emission. 相似文献
45.
《Diamond and Related Materials》2005,14(10):1669-1672
Disparities prevail among the reported hardness and fracture toughness values for hard and brittle materials. A better understanding of the physical nature of hardness and fracture toughness and a standardized technique for reliable measurements of these quantities is urgently needed. We strongly recommend the use of the measured hardness after the bend in the hardness versus load (H−FLoad) curve, when the hardness approaches its asymptotic value. The present work reports a systematic study of hardness and fracture toughness on moissanite (single crystal hexagonal silicon carbide, 6H-SiC) samples. The measurements were performed over a broad load range from 0.49 to 294 N with the direct indentation method. Asymptotic values of Knoop hardness of HK = 19 GPa and Vickers hardness of HV = 22 GPa were reached at a high load between 50 N and 100 N. A consistent fracture toughness of KIC = 1.8 MPa·m1/2 was obtained across the entire load range. Our study presents experimental results for the hardness and fracture toughness of moissanite in the asymptotic-hardness region, and it raises concern regarding the application of moissanite single crystals as anvil material under shear/fracture conditions. 相似文献
46.
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48.
玻纤增强聚苯硫醚复合材料的增韧研究 总被引:1,自引:0,他引:1
针对玻纤增强聚苯硫醚材料韧性差的问题,对聚苯硫醚傲璃纤维复合体系的增韧进行了研究,考察了玻纤、改性聚合物、有机超细粒子对复合材料力学性能的影响。采用基体增韧(预增韧)与有机超细粒子增韧技术,在保持复合材料拉伸强度和模量的同时,较大地提高了冲击强度,获得了综合力学性能优异的纤维增强聚苯硫醚材料。 相似文献
49.
50.
钢铁厂采用的变频器有很多种,现针对常用的丹佛斯、两门子、ABB变频器出现的故障,总结概括维修经验,对部分故障进行分析,供有关技术人员在维修变频器时借鉴. 相似文献