检索结果-南通市图书馆

LEWIS　ACIDIC　SITES　NOT　ASSOCIATED　WITH　EXTRA-FRAMEWORK　ALUMINUM　IN　DEHYDROXYLATED　ZEOLITE　HZSM-5

Chinese Chemical Letters 1996年第5期7卷 491-492页

作者： Tie Hong CHEN Ping Chuan SUN Ai Ju MEN Zhong Yong Zhen Ya GUO Jing Zhong WANG Da Tong DING He Xuan LI (Department of Chemistry Nankai University Tianjin, 300071)(the State key laboratory of Funcrional Polymericmeric Materials for Adsorption and sepa Department of Chemistry Nankai University Tianjin 300071 State key Lab. Funct. P.M.A./S. Nankai University Tianjin 300071 Department of Physics Nankai University Tianjin 300071

Abstract: Zeolite HZSM-5 calcined at different temperatures were studied by29Si MAS NMR and EPR method. It was concluded that in certain temperature range, dealumination did not necessarily occur simultaneously with framework dehydroxylation and thus framework Lewis acidic sites emerged. Two processes may be operative with one of them being predominant at different temperatures.

关键词：

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Potential Predictability of Seasonal Extreme Precipitation Accumulation in China

Potential Predictability of Seasonal Extreme Precipitation A...

引用

第34届中国气象学会年会

作者： Wenguang Wei Zhongwei Yan P.D.Jones key laboratory of Regional Climate–Environment for Temperate East Asia Institute of Atmospheric Physics Chinese Academy of Sciences University of Chinese Academy of Sciences Climatic Research Unit School of Environmental Sciences University of East Anglia Center of Excellence for Climate Change Research Dept of Meteorology King Abdulaziz University

The potential predictability of seasonal extreme precipitation accumulation（sepa） across China’s mainland is evaluated, based on daily precipitation observations during 1960-2013 at 675 stations. The potential predictability value（PPV） of sepa is calculated for each station by decomposing the observed sepa variance into a part associated with stochastic daily rainfall variability and another part associated with longer timescale climate processes. We construct a Markov Chain model for each station and apply a Monte Carlo simulation to estimate the stochastic part of the variance. The results suggest that there are more potentially predictable regions for summer than for the other seasons, especially over the Yangtze River valley, North China Plain and northwestern China. There are also regions of large PPVs in southern China for autumn and winter and northwestern China for spring. The sepa series for the regions of large PPVs are deemed non-stochastic, either with long-term trends（e.g., increasing trends in inland northwestern China） or significant correlation with well-known large-scale climate processes（e.g., East Asian Winter Monsoon for southern China in winter, El Ni?o for the Yangtze River valley in summer）. This fact not only verifies our claim that the regions have potential predictability but also facilitates predictive studies of the regional extreme precipitation and the mechanisms associated with large-scale climate processes.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：