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HUA Hui LI ZhiHuan YE YanLin JIANG DongXing LOU JianLing LI XiangQing & XU FuRong School of Physics State Key Laboratory of Nuclear Physics Technology Peking University Beijing China 《中国科学:物理学 力学 天文学(英文版)》2011,(Z1)
The β-decay studies of neutron-rich 18,21N isotopes have been performed using β-n, β-γ, and β-n-γ coincidence methods. The 18,21N ions were produced by the fragmentation of the 22Ne and 26Mg beams, respectively, on a thick beryllium target. The time of flight of the emitted neutrons following the β-decay of 18,21N was measured by a neutron detector system with wide energy detection range and low-energy detection threshold. In addition, several clover germanium detectors were used to detect the β-delayed γ-r... 相似文献
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利用接触角、XPS、SFG、AFM等技术研究了环己酮、甲苯和三氟甲苯为成膜溶剂所得聚甲基丙烯酸甲酯-b-聚(甲基丙烯酸-2-全氟辛基乙酯)(PMMA—b—PFMA)嵌段共聚物膜的表面结构与性能.发现浇铸成膜时成膜溶剂对聚合物氟化组分向表面富集程度的影响相对较小,而旋涂成膜时溶剂的影响很大.不管以何种形式成膜,三氟甲苯溶剂最有利于氟化组分向表面富集,甲苯次之,环己酮最差.这一现象与溶剂的挥发速度无关.聚合物在溶液中的聚集结构、气/液界面结构是造成成膜方式对聚合物表面结构与性能产生巨大影响的主要原因.当聚合物在溶液中形成以PFMA为核、PMMA为冠的胶束结构时,在溶液固化过程中氟化组分向表面富集需要较长的时间,这时由于成膜方法直接影响溶液的固化速度,造成其对氟化组分向表面富集的程度影响很大.当聚合物在溶液中以单分子或松散聚集体存在,在溶液固化过程中氟化组分向表面富集的速度很快,这时成膜方法对氟化组分向表面富集的程度影响很小.以上结果无论对理论研究还是应用研究都具有重要意义. 相似文献
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Along with the development of the radioactive nuclear beam facility, the study of the structure of unstable nuclei has progressed rapidly over the last few decades. Due to the weakly binding property, the structure information of the unstable nuclei comes primarily from the scattering or reaction experiments. Therefore it would be very important to understand clearly the reaction mechanism involved in the experiment. We outlined here the major reaction mechanisms which are adequate to the study of unstable nuclei, with the focus on the new phenomena and methods in comparison with those with traditional stable nucleus beam. Especially emphasized are the breakup and knockout reactions, developed as accurate tools for spectroscopy investigation into the nuclear structure with low intensity secondary beam. Couplings of the breakup channel to the elastic scattering and the fusion and transfer reactions are also reviewed. 相似文献
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YanLin Gao XiuYan Li XiaoFeng Shi Zhi Yang LiChun Xu RuiPing Liu 《中国科学:物理学 力学 天文学(英文版)》2014,57(8):1519-1525
The structural,electronic,and optical absorption properties of TiO2 nanotube(TiO2NT)with Cun clusters(n=1–4)adsorbed on its surface have been investigated based on density functional theory calculations.The TiO2NT is constructed by rolling up a(101)sheet of anatase TiO2 around the[1 01]direction;the ground states of Cun/TiO2NT systems are determined by analyzing the average adsorption energies.Calculation results show that odd-even oscillations occur for the average adsorption energy,the Cu–O bond length,and the amount of transferred electrons,with the increase in Cun cluster size;and the Cun/TiO2NTs with odd n’s demonstrate stronger interaction between the Cun cluster and the TiO2NT.Also,the impurity states introduced by the Cun cluster to the band gap of TiO2NT cause an obvious redshift of the optical absorption spectrum toward the visible light region,especially for the even n cases. 相似文献
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YiDi Chen Yun Zhang JianLing Lou DanYang Pang YanLin Ye Wei Liu Ying Jiang Gen Li 《中国科学:物理学 力学 天文学(英文版)》2018,(11)
This study aims to analyze the differential cross sections(DCSs) of elastic scattering and total reaction cross sections(TRCSs) of the loosely-bound deuteron projectile impinging on 1 p-shell nuclei, such as9 Be,12 C, and16 O, at incident energies ranging between10.6 and 171 MeV using the continuum discretized coupled channel(CDCC) method. By fitting the experimental data for the DCSs and TRCSs, energy-dependent renormalization factors for the real and imaginary parts of the nucleon-nucleus opticalmodel potentials deduced from the studies proposed by Koning and Delaroche(KD02) and by Watson, Singh, and Segel(WSS),are obtained. It is found that with the WSS potential, which was obtained specifically for 1 p-shell nuclei, the CDCC calculations can simultaneously reproduce both the DCSs and the TRCSs. The results show that it is important to choose appropriate optical potentials to describe deuteron-induced reactions. 相似文献
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CAO ZhongXin & YE YanLin State Key Laboratory of Nuclear Physics Technology School of Physics Peking University Beijing China 《中国科学:物理学 力学 天文学(英文版)》2011,(Z1)
Along with the development of the radioactive nuclear beam facility, the study of the structure of unstable nuclei has progressed rapidly over the last few decades. Due to the weakly binding property, the structure information of the unstable nuclei comes primarily from the scattering or reaction experiments. Therefore it would be very important to understand clearly the reaction mechanism involved in the experiment. We outlined here the major reaction mechanisms which are adequate to the study of unstable ... 相似文献