An apparatus was set up for in situ UV- Vis determintion of ethylene polymerization under atmospheric pressure. In three different solvents, tetrahydrofuran(THF), chlorobenzene and dimethyl formamide (DMF), and using ...An apparatus was set up for in situ UV- Vis determintion of ethylene polymerization under atmospheric pressure. In three different solvents, tetrahydrofuran(THF), chlorobenzene and dimethyl formamide (DMF), and using MAO as cocatalyst,α- diimine/nickel catalytic system was prepared for ethylene polymerization with the UV- Vis testing system. In THF, active peak at 545 nm and inactive peak at 660 nm were observed. In chlorobenzene, active peak at 520 nm, 570 nm, and inactive peak at 660 nm were also observed. The regularities of growth and disappearence of active peaks were investigated. The structure of active species and solvent effect were discussed.展开更多
美国国立医学图书馆成立于一八三六年,到今年计有一百五十年的历史。位于首都华盛顿特区的郊区。其中的MEDLARS系统,是美国较早的一个计算机情报检索网络。MEDLARS资料库是在1964年开始设立的,那时最先的用途是以电子计算机使用MEDLARS...美国国立医学图书馆成立于一八三六年,到今年计有一百五十年的历史。位于首都华盛顿特区的郊区。其中的MEDLARS系统,是美国较早的一个计算机情报检索网络。MEDLARS资料库是在1964年开始设立的,那时最先的用途是以电子计算机使用MEDLARS磁带而印刷医学索引(Index Medicus)月刊和医学索引年度积累本(Annual Canlulative Index Medicus)。1970年,国立医学图书馆鉴于纽约州立大学联机网络的发展成功,成立了AIM—TWX联机检索网络。AIM(Abridged Index Medicus)是医学索引的策略本,只包括一百种最主要医学期刊的索引。TWX(Tele—typewriter)是贝尔(Bell)电话公司的全国性电传打字机通信系统。展开更多
文摘An apparatus was set up for in situ UV- Vis determintion of ethylene polymerization under atmospheric pressure. In three different solvents, tetrahydrofuran(THF), chlorobenzene and dimethyl formamide (DMF), and using MAO as cocatalyst,α- diimine/nickel catalytic system was prepared for ethylene polymerization with the UV- Vis testing system. In THF, active peak at 545 nm and inactive peak at 660 nm were observed. In chlorobenzene, active peak at 520 nm, 570 nm, and inactive peak at 660 nm were also observed. The regularities of growth and disappearence of active peaks were investigated. The structure of active species and solvent effect were discussed.
文摘美国国立医学图书馆成立于一八三六年,到今年计有一百五十年的历史。位于首都华盛顿特区的郊区。其中的MEDLARS系统,是美国较早的一个计算机情报检索网络。MEDLARS资料库是在1964年开始设立的,那时最先的用途是以电子计算机使用MEDLARS磁带而印刷医学索引(Index Medicus)月刊和医学索引年度积累本(Annual Canlulative Index Medicus)。1970年,国立医学图书馆鉴于纽约州立大学联机网络的发展成功,成立了AIM—TWX联机检索网络。AIM(Abridged Index Medicus)是医学索引的策略本,只包括一百种最主要医学期刊的索引。TWX(Tele—typewriter)是贝尔(Bell)电话公司的全国性电传打字机通信系统。
