期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
不同添加剂对聚偏氟乙烯膜结构和性能的影响 被引量:8
1
作者 李倩 许振良 +1 位作者 俞丽芸 袁国林 《高分子材料科学与工程》 EI CAS CSCD 北大核心 2010年第2期80-83,共4页
利用非溶剂相转化法(NIPS),以N,N-二甲基乙酰胺(DMAc)为溶剂,聚乙烯吡咯烷酮(PVPK30)和一水合氯化锂(LiCl·H2O)为混合添加剂,改变PVPK30-LiCl·H2O配比得到不同性能和结构的聚偏氟乙烯(PVDF)膜。考察了不同种类添加剂(PVP、LiC... 利用非溶剂相转化法(NIPS),以N,N-二甲基乙酰胺(DMAc)为溶剂,聚乙烯吡咯烷酮(PVPK30)和一水合氯化锂(LiCl·H2O)为混合添加剂,改变PVPK30-LiCl·H2O配比得到不同性能和结构的聚偏氟乙烯(PVDF)膜。考察了不同种类添加剂(PVP、LiCl·H2O、H2O和PEG200)及不同配比的PVPK30-LiCl·H2O添加剂对PVDF成膜分相延时时间、分相速率的影响。实验结果表明,采用PVPK30为添加剂,铸膜液呈瞬时分相行为,膜通量很大;增大混合添加剂中PVPK30/LiCl·H2O的比例,会增加液液分相速率,使膜结构中的大孔贯通整个膜结构。 展开更多
关键词 聚偏氟乙烯 混合添加剂 分相延迟时间 分相速率
下载PDF
Numerical analysis on car-following traffic flow models with delay time
2
作者 李莉 施鹏飞 《Journal of Zhejiang University-Science A(Applied Physics & Engineering)》 SCIE EI CAS CSCD 2006年第2期204-209,共6页
Effects of the speed relaxation time on the optimal velocity car-following model (OVM) with delay time due to driver reaction time proposed by Bando et al.(1995) were studied by numerical methods. Results showed that ... Effects of the speed relaxation time on the optimal velocity car-following model (OVM) with delay time due to driver reaction time proposed by Bando et al.(1995) were studied by numerical methods. Results showed that the OVM including the delay is not physically sensitive to the speed relaxation times. A modified car-following model is proposed to overcome the deficiency. Analyses of the linear stability of the modified model were conducted. It is shown that coexisting flows appear if the initial homogeneous headway of the traffic flow is between critical values. In addition, phase transitions occur on varying the initially homogeneous headway. 展开更多
关键词 Car-following models Delay time Relaxation time Phase transitions
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部