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基于静态和动态休止角的钛白粉离散元仿真参数标定 被引量:2
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作者 吴震 王利强 +1 位作者 徐立敏 高伟俊 《中国粉体技术》 CSCD 2023年第4期108-119,共12页
粉体物料在进行离散元模拟前需要通过参数标定过程来获得精确的离散元仿真参数,现有的参数标定多以静态休止角作为单一的响应值,并不能充分体现粉体的真实性能。为了提高钛白粉离散元仿真参数的精度,选取钛白粉的静态休止角和动态休止... 粉体物料在进行离散元模拟前需要通过参数标定过程来获得精确的离散元仿真参数,现有的参数标定多以静态休止角作为单一的响应值,并不能充分体现粉体的真实性能。为了提高钛白粉离散元仿真参数的精度,选取钛白粉的静态休止角和动态休止角作为宏观响应指标,使用自制的测定装置测得钛白粉的静态和动态休止角的平均值;根据颗粒的尺寸相似原则和减小刚度原理对钛白粉颗粒的粒径和切变模量进行简化,并建立离散元仿真模型;通过单因素试验排除部分对休止角影响较小的离散元仿真参数;应用Box-Behnken试验分别建立静态和动态休止角的二阶回归方程,以实际测定的休止角为目标值对2个回归方程进行寻优求解,获得最优的离散元仿真参数组合;对离散元仿真参数进行实验验证,实现对钛白粉离散元仿真参数标定。结果表明:当钛白粉-钛白粉静摩擦系数为0.51,滚动摩擦系数为0.29,钛白粉-不锈钢静摩擦系数为0.62,滚动摩擦系数为0.17时,钛白粉的离散元仿真参数值组合最优;仿真得到的静态和动态休止角分别为40.4°、66.2°,与实际测定值的相对误差分别为1.22%、1.07%。 展开更多
关键词 钛白粉 颗粒简化 静态休止角 动态休止角 离散单元法 参数标定
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Facile Fabrication of Platinum Nanoparticles Supported on Nitrogen-doped Carbon Nanotubes and Their Catalytic Activity
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作者 Ling-ling Wang Long Shen +2 位作者 Hai-ying Jin Lu-ping Zhu Li-jun Wang 《Chinese Journal of Chemical Physics》 SCIE CAS CSCD 2014年第3期327-331,共5页
A facile impregnation method under mild condition is designed for synthesis of highly dispersed Pt nanoparticles with a narrow size of 4-7 nm on nitrogen-doped carbon nanotubes (CNx). CNx do not need any pre-surface... A facile impregnation method under mild condition is designed for synthesis of highly dispersed Pt nanoparticles with a narrow size of 4-7 nm on nitrogen-doped carbon nanotubes (CNx). CNx do not need any pre-surface modification due to the inherent chemical activity. The structure and nature of Pt/CNx were characterized by X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive spectroscopy spectrum. All the experimental results revealed that the large amount of doped nitrogen atoms in CNx was virtually effective for capturing the Pt(IV) ions. The improved surface nitrogen functionalities and hydrophilicity contributed to the good dispersion and immobi- lization of Pt nanoparticles on the CNx surface. The Pt/CNx served as active and reusable catalysts in the hydrogenation of allyl alcohol. This could be attributed to high dispersion of Pt nanoparticles and stronger interaction between Pt and the supports, which prevented the Pt nanoparticles from aggregating into less active Pt black and from leaching as well. 展开更多
关键词 Carbon nanotube Nitrogen doping Allyl alcohol hydrogenation Pt nanoparticles Heterogeneous catalyst
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