排序方式： 共有3条查询结果，搜索用时 31 毫秒
1
1.
正泡沫铝材料是近年来被广泛研究的新型功能-结构一体化材料,其显著特征是在纯铝或铝合金基体中存在着大量毫米级的宏观孔洞。根据孔洞的连通性可将泡沫铝分为闭孔和开孔两大类,前者气孔独立分布于基体之中,后者则呈三维连通结构。对于泡沫铝,孔洞是研究者所期望出现的功能结构,是获得泡沫金属优化指标的实现手段,而孔结构的控制则主要依赖于制备方法和工艺技术。功能性气孔与基体金属骨架形成的耦合结构为泡沫铝带来一系列致密金属所没有的优异特性,如轻质高强、吸能缓冲、阻尼减震、电磁屏蔽、隔音吸音、阻燃隔热,以及大的比表面积和优良的渗透性等,因而在汽车制造、航空航天、国防军工、电子工程和建筑声 相似文献
2.
A large amount of residue including benzoic acid, benzyl benzoate and fluorenone can form in the production of benzoic acid
by oxidizing toluene. To recycle the resources and reduce secondary pollution, the treatment of benzoic acid residue was carried
out to obtain the three purified materials by flash-vacuum distillation combination method, and the influence of the operating
parameters, such as the top pressure, reflux ratio and top and bottom temperatures was investigated to obtain the best operating
conditions. The experimental results show that the benzoic acid purity can reach 97% through distillation under the following
conditions: the top pressure is 1 600 Pa, the bottom temperature is 190–200 °C, the top temperature is 130–135 °C, and reflux
ratio is 5:1. The best operating conditions for benzyl benzoate distillation column are: the top pressure is 400 Pa, bottom
temperature is 250–260 °C, the top temperature is 150–160 °C, and reflux ratio is 5:1. The benzyl benzoate purity can reach
95% and the fluorenone purity can reach 92%. When refined by melt crystallization, the benzoic acid purity can be improved
up to 99.6%, and the purities of benzyl benzoate and fluorenone are both above 95%. 相似文献
3.
1