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Polymerization of Isoprene by Amidinate-Ligated Yttrium Catalysts.Unprecedented Switching of the Regio-and Stereoselectivity with an Alkyl Aluminum Compound
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作者 Masayoshi Nishiura Masahiro Yuki 《复旦学报(自然科学版)》 CAS CSCD 北大核心 2007年第5期816-,共1页
1 Results Search for catalysts which can control the regio- and stereoselectivity for olefin polymerization is a very important research subject.For the polymerization of isoprene,we have recently achieved,for the fir... 1 Results Search for catalysts which can control the regio- and stereoselectivity for olefin polymerization is a very important research subject.For the polymerization of isoprene,we have recently achieved,for the first time,the isospecific 3,4 polymerization by using a cationic rare earth metal alkyl catalyst bearing a silylene-linked cyclopentadieny-phosphido ligand[1], and the cis-1,4 living polymerization by a bis(phosphinophenyl)amido-ligated rare earth metal catalyst[2]. In addition to these ligan... 展开更多
关键词 amidinate ligand rare earth metal POLYMERIZATION aluminum reagent ISOPRENE
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Study of Proton Resonances in ^(22)Mg by Resonant Elastic Scattering of ^(21)Na+p and Its Astrophysical Implication in ^(18)Ne(α,p) ^(21)Na Reaction Rate
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作者 S.Kubono T.Teranishi +13 位作者 M.Notani H.Baba S.Nishimura J.Y.Moon M.Nishimura S.Michimasa H.Iwasaki Y.Yanagisawa N.Hokoiwa M.Kibe J.H.Lee S.Kato Y.Gono C.S.Lee 《原子核物理评论》 CAS CSCD 北大核心 2009年第S1期153-157,共5页
Proton resonant states in 22Mg have been investigated by the resonant elastic scattering of 21Na+p. The 21Na beam with a mean energy of 4.00 MeV/u was separated by the CNS radioactive ion beam separator(CRIB) and bomb... Proton resonant states in 22Mg have been investigated by the resonant elastic scattering of 21Na+p. The 21Na beam with a mean energy of 4.00 MeV/u was separated by the CNS radioactive ion beam separator(CRIB) and bombarded a thick(CH2)n target. The energy spectra of recoiled protons were measured at scattering angles of θcm ≈172° and 146°,respectively. A new state at 7.06 MeV has been observed clearly and another new one at 7.28 MeV is tentatively identified due to its low statistics. The proton resonant parameters were deduced from an R-matrix analysis of the differential cross section data. The astrophysical resonant reaction rate for the 18Ne(α,p)21Na reaction has been estimated,and it is about five times larger than that assumed before. 展开更多
关键词 NUCLEAR ASTROPHYSICS reaction rate NUCLEAR structure and property
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