Preparation and Characterization of Flame-Retardant Melamine Cyanurate/Polyamide 6Nanocomposites by In Situ PolymerizationZhi-Yong Wu,1,2Wei Xu,1,2Yao-Chi Liu,1Jin-Kui Xia,2Qian-Xin Wu,2Wei-Jian Xu 1艺
【双语印章史】石质印材的品类与赏鉴(三)石质印材的品类与赏鉴(三)Categories and Esthetics of Stone Seal Materials (Part three)昌化石系产于浙江临安市上溪乡,其地原属昌化县,故一直沿称旧名。昌化石亦属于叶腊石类,主要矿区在玉岩山。昌化石质稍带粘涩,色彩有白、黑、黄、灰等多种。其中冻石晶莹滋润,有牛角冻、藕粉冻、黄冻等传统名品,具有较高的观