Yuxian HAN
,
Tai QIU
材料科学技术（英文）
Sol-gel method was employed for the preparation of nanoscale tungsten powder. The effects of different preparation conditions on particle size were discussed and the optimum preparation condition was found. The products were characterized by X-ray diffraction, scan electron microscopy and so on. The results show that the intermediate is monoclinic WO3, its particle shape is approximately spherical, and the particle size distribution is narrow. The average particle size is about 60 nm. After deoxidization, WO3 turns into cubic tungsten powder with small particle size (average particle size about 120 nm) and narrow size distribution.
关键词:
Sol-gel method
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桂南
,
樊建人
,
陈松
工程热物理学报
本文采用直接数值模拟计算了Re=669,S=1.42强旋流中的颗粒运动特性.计算的部分流动条件依照SommerfeId & Qiu的实验条件进行模化.模拟的结果揭示了旋流近场的颗粒运动的浓度、速度的时均量和脉动值的统计分布特性.
关键词:
旋流
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颗粒运动
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直接数值模拟
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统计特性
