Cordierite precursor was obtained through a process, which involved the decomposition of metal nitrates on the surface of ultrafine carbon black powder between 100-300℃ and the gasification of the carbon black at hig...Cordierite precursor was obtained through a process, which involved the decomposition of metal nitrates on the surface of ultrafine carbon black powder between 100-300℃ and the gasification of the carbon black at higher temperature in air. The average size of the particles, which were heat-treated at 700℃ for 10h, is about 1020nm, and the specific surface area is about 129m 2/g. The experimental results show that the ultrafine particles of cordierite precursor can be produced by this process. The precursor powder was calcined at different temperatures. X-ray diffraction examination indicates that β-quartz is crystallized from the amorphous matrix around 850℃ firstly and then MgO-Al 2O 3 spinel and α-cordierite appears. Above 1000℃, MgO-Al 2O 3 spinel and cristobalite disappear gradually and form an intermediate phase (sapphirine). At around 1300℃, the main phase is α-cordierite, and no other phase is detected.展开更多
One of the most severe problems affecting the efficient operations of gas pipelines is corrosion caused by black powder. According to the literature, the primary source for the existence of black powder is condensed w...One of the most severe problems affecting the efficient operations of gas pipelines is corrosion caused by black powder. According to the literature, the primary source for the existence of black powder is condensed water. In this case study, the temperature (40°C) of the sales gas is much higher than its dew point (9.24°C). The water is therefore in vapor phase. It is then proposed to remove water vapor from the gas at the entrance of the plant using an adsorption process. The recommended technology is the Layered Bed Temperature-Swing Adsorption (LBTSA) with micro-channels with molecular sieve zeolite 4A and activated alumina as adsorbents. In the case of presence of aerosols that could condense water, it is suggested to utilize a RED (Rare Earth Drum) magnetic separator in order to remove black powder from the gaseous feed.展开更多
本工作以拓宽结构型吸波复合材料的吸收频带为目的,在玻璃纤维增强尼龙复合材料中同时引入磁损耗型吸波剂羰基铁粉(Carbonyl iron powder,CIP)和电阻损耗型吸波剂炭黑(Carbon black,CB),采用热压成型工艺制备了CB-CIP@SiO_(2)/玻璃纤维...本工作以拓宽结构型吸波复合材料的吸收频带为目的,在玻璃纤维增强尼龙复合材料中同时引入磁损耗型吸波剂羰基铁粉(Carbonyl iron powder,CIP)和电阻损耗型吸波剂炭黑(Carbon black,CB),采用热压成型工艺制备了CB-CIP@SiO_(2)/玻璃纤维/尼龙6(CB-CIP@SiO_(2)-GF/PA6)吸波复合材料。重点研究了CIP表面包覆SiO_(2)薄膜及其加入量对复合材料微波吸收和力学性能的影响。研究结果表明:SiO_(2)薄膜包覆不仅解决了CIP氧化问题,同时改善了复合材料的阻抗匹配特性,使得CIP与CB协同提升了复合材料的吸波性能。在保障复合材料具有良好吸波性能前提下,CIP的负载量从70wt%降低至30wt%左右,大大减轻了复合材料的质量。其中,掺量为1wt%CB和30wt%CIP@SiO_(2)的吸波复合材料的有效吸收带宽在材料厚度为1.91~1.95 mm时超过了5.6 GHz,且覆盖了整个Ku波段。这种方法一方面拓宽了吸波复合材料的有效吸收带宽,实现了宽带吸波。另一方面,CIP@SiO_(2)颗粒与GF的纤维实现共同增强,提升了复合材料的整体力学性能。当CIP@SiO_(2)的含量为40wt%时,复合材料的力学性能最佳,弯曲强度为(212.8±9.8)MPa,剪切强度为(21.0±1.4)MPa,摆锤冲击强度为(64.4±6.2)kJ/m^(2)。展开更多
文摘Cordierite precursor was obtained through a process, which involved the decomposition of metal nitrates on the surface of ultrafine carbon black powder between 100-300℃ and the gasification of the carbon black at higher temperature in air. The average size of the particles, which were heat-treated at 700℃ for 10h, is about 1020nm, and the specific surface area is about 129m 2/g. The experimental results show that the ultrafine particles of cordierite precursor can be produced by this process. The precursor powder was calcined at different temperatures. X-ray diffraction examination indicates that β-quartz is crystallized from the amorphous matrix around 850℃ firstly and then MgO-Al 2O 3 spinel and α-cordierite appears. Above 1000℃, MgO-Al 2O 3 spinel and cristobalite disappear gradually and form an intermediate phase (sapphirine). At around 1300℃, the main phase is α-cordierite, and no other phase is detected.
文摘One of the most severe problems affecting the efficient operations of gas pipelines is corrosion caused by black powder. According to the literature, the primary source for the existence of black powder is condensed water. In this case study, the temperature (40°C) of the sales gas is much higher than its dew point (9.24°C). The water is therefore in vapor phase. It is then proposed to remove water vapor from the gas at the entrance of the plant using an adsorption process. The recommended technology is the Layered Bed Temperature-Swing Adsorption (LBTSA) with micro-channels with molecular sieve zeolite 4A and activated alumina as adsorbents. In the case of presence of aerosols that could condense water, it is suggested to utilize a RED (Rare Earth Drum) magnetic separator in order to remove black powder from the gaseous feed.
