期刊文献+
共找到2篇文章
< 1 >
每页显示 20 50 100
产生多焦环的衍射相位元件设计的新方法 被引量:1
1
作者 张国庆 顾本源 杨国桢 《物理学报》 SCIE EI CAS CSCD 北大核心 1996年第10期1647-1654,共8页
基于光学变换的一般理论,提出了一种产生多焦环的衍射相位元件的新设计方法,焦环的数目、位置和焦环的宽度可以任意设定.在高斯型激光束照明下进行模拟设计,并讨论了相位量化对结果的影响.理论计算表明。
关键词 衍射相位元件 多焦环 光学变换
原文传递
Synthesis and Characterization of Condensed Polynuclear Aromatic Resin Derived from Ethylene Tar 被引量:7
2
作者 Wu Mingbo Shi Yangyang +5 位作者 Li Shibin Wang Yuwei Tan Minghui Wang Ding Zheng Jingtang Tsubaki Noritatsu 《China Petroleum Processing & Petrochemical Technology》 SCIE CAS 2012年第4期42-47,共6页
As a kind of low-cost and readily available industrial byproduct, ethylene tar (ET) was for the first time utilized for the preparation of heat-resistant condensed polynuclear aromatic resin (COPNAR). The basic pr... As a kind of low-cost and readily available industrial byproduct, ethylene tar (ET) was for the first time utilized for the preparation of heat-resistant condensed polynuclear aromatic resin (COPNAR). The basic properties of ET and the resulted COPNAR were characterized by FT-IR, IH-NMR, TGA and elemental analysis. The test results showed that ET with high aromatic content (〉50%) was suitable for the synthesis of COPNAR with superior heat resistance. The average molecular structure of ET was obtained by means of the improved Brown-Ladner method, and the reaction mechanism was considered as an acid-catalyzed positive ion-typed polymerization. Our findings have provided a new route to develop ET into technology-added heat-resistant resins. 展开更多
关键词 condensed polynuclear aromatic resin ethylene tar 1 4-benzenedimethanol heat resistance
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部