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91.
92.
喹啉不溶物(QI)是煤焦化过程中带入的固体杂质,煤沥青中喹啉不溶物的脱除对于煤沥青的深加工非常重要。采用溶剂沉降法脱除煤沥青中喹啉不溶物,考察了溶剂配比、沉降温度、沉降时间以及溶剂种类对净化沥青QI含量和收率的影响。结果表明,在一定范围内,温度越高,越有利于QI的脱除,当温度达到160℃以上对沉降的影响较小;以洗油与煤油调制的混合溶剂较单纯溶剂油有更好的沉降效果;沉降时间越长,QI脱除率越高,净化沥青的收率越低。 相似文献
93.
Luis J. Salazar-Gastélum Mara Beltrán-Gastélum Julio C. Calva-Yañez Shui Wai Lin Daniel Chávez-Velasco Moisés I. Salazar-Gastélum Sergio Pérez-Sicairos 《应用聚合物科学杂志》2023,140(4):e53359
Anion exchange ionomer (AEI) is a critical component used on anion exchange membrane fuel cell (AEMFC) and alkaline water electrolyzer (AWE). In this work, quaternized polysulfone with different functionalization degree were used as an ionomer to evaluate the performance in the oxygen reduction reaction (ORR) and hydrogen oxidation reaction (HOR), both implied in the operation of AEMFC and AWE. The synthesized ionomer exhibited a better performance in both reactions in comparison to the commercial AEI Aemion®. PSf-130 exhibited better performance, since IEC and surface area increases twice regarding the same parameters in the PSf-60. The PSf-130 conductivity increases three times regarding the value exhibited by PSf-60. Finally, the Jlim and Jk increases 67% and 100% for ORR. On the other hand, the same catalytic parameter increased 44% and 35% for HOR comparing both polysulfone-based ionomers. The Tafel slope values do not showed drastically changes for different ionomers indicating the same rate determining step (RDS) and the same mechanism in both reactions for all the ionomers. 相似文献
94.
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96.
Ji Zou Shui‐Gen Huang Kim Vanmeensel Guo‐Jun Zhang Jef Vleugels Omer Van der Biest 《Journal of the American Ceramic Society》2013,96(4):1055-1059
A carbide boronizing method was first developed to produce dense boron carbide‐ zirconium diboride (“B4C”–ZrB2) composites from zirconium carbide (ZrC) and amorphous boron powders (B) by Spark Plasma Sintering at 1800°C–2000°C. The stoichiometry of “B4C” could be tailored by changing initial boron content, which also has an influence on the processing. The self‐propagating high‐temperature synthesis could be ignited by 1 mol ZrC and 6 mol B at around 1240°C, whereas it was suppressed at a level of 10 mol B. B8C–ZrB2 ceramics sintered at 1800°C with 1 mole ZrC and 10 mole B exhibited super high hardness (40.36 GPa at 2.94 N and 33.4 GPa at 9.8 N). The primary reason for the unusual high hardness of B8C–ZrB2 ceramics was considered to be the formation of nano‐sized ZrB2 grains. 相似文献
97.
98.
Carbon black, graphite and carbon fibre were employed to design and prepare electrically conductive asphalt mixtures containing single filler or mixed fillers of conductive powder plus carbon fibre. The effects of filler type, filler content and mixed fillers on the resistivity of asphalt concrete were investigated. Experimental results showed that the insulating-conductive percolation transition of the resistivity under the function of filler content appears in the single-filler composites and the percolation threshold is approximately 12%, 10%, and 5% by volume percentage of the binder phase for carbon black, graphite and carbon fibre respectively. The combination function of mixed fillers has appreciable advantages over single powder filler, but no obvious advantages over simple fiber in the conductivity improvement at the same total filler content. But the addition of small amounts of expensive fibers to larger amounts of cheaper CB or graphite can be a cost effective system. Scanning electron microscope images provide insight into the mechanisms of conductivity enhancement for mixed fillers. Conductive filler particles exhibit the short-range contacts or connections in asphalt concrete, whereas carbon fibres exhibit a long-range conductive bridging effect and short-circuit effect because of the high aspect ratio. 相似文献
99.
采用熔融共混工艺和熔融浸渍分别制备了短玻璃纤维增强聚苯硫醚复合材料(PPS/SGF)和长玻璃纤维增强聚苯硫醚(PPS/LGF)复合材料,并对复合材料的力学性能和耐热性能进行了对比分析。研究结果表明,在玻璃纤维质量分数为30%时,PPS/SGF和PPS/LGF复合材料的拉伸强度分别为110 MPa和122 MPa;弯曲强度分别为175 MPa和208 MPa;弯曲弹性模量分别为8 GPa和9 GPa;缺口冲击强度和无缺口冲击强度分别为7.7,11.9 kJ/m2和31,37 kJ/m2。PPS/LGF复合材料的拉伸强度、弯曲强度、弯曲弹性模量、缺口冲击强度和无缺口冲击强度相较于PPS/SGF复合材料分别提高了11.0%,18.9%,11.3%,54.5%和19.4%。PPS/SGF和PPS/LGF复合材料的热变形温度分别达到250℃和275℃,PPS/LGF复合材料的热变形温度高于PPS/SGF复合材料热变形温度10%。 相似文献
100.
Qingliang Shan Qian Ma Jiawei Lian Caiyu Yao Anze Shui 《International Journal of Applied Ceramic Technology》2022,19(5):2675-2685
In this research, for studying the influence of size and heat treatment temperature of initial Al(OH)3 on the physical properties of porous mullite ceramics, porous mullite ceramics were prepared by in situ reaction sintering of amorphous silica and treated Al(OH)3. The transition phases χ-Al2O3, к-Al2O3, and stable phase α-Al2O3 can be obtained in turn when the treatment temperature of raw Al(OH)3 is 500, 1000, and 1500°C, respectively. The coarser the raw Al(OH)3, the higher the strength of porous mullite ceramics. When the sintering temperature is 1500°C, the bending strengths of PS500-C, PS1000-C, and PS1500-C (PSx-C represents that the specimen was prepared by the coarse grade Al(OH)3, which was previously treated at x°C) are 40.3 ± 2.1, 54.9 ± 5.2, and 64.8 ± 4.8 MPa, respectively. In addition, although the activated Al2O3 can decrease the formation temperature (∼100°C) of porous mullite ceramics, the strength and density of porous mullite ceramics prepared by activated Al2O3 will decrease at the same sintering temperature. It is believed that the increase of defects and pores during the phase transformation should be responsible for this phenomenon. 相似文献