正电子概况XⅫⅡ 正电子技术在材料科学中 的应用-nanoparticles 叶邦角 核固体物理研究室 Laboratory of Nuclear Solid State Physics,USTC PDF文件使用"pdfFactory”试用版本创建耀w.fineprint.cn
正电子技术在材料科学中 的应用--- nanoparticles 叶邦角 核固体物理研究室 Laboratory of Nuclear Solid State Physics, USTC 正电子概况XII
Positron for Nano-particles 纳米粒子 二.纳米粒子嵌入 三，纳米粒子在表面 PDF文件使用"pdfFactory”试用版本创建ww.fineprint.cn
Positron for Nano-particles 二. 纳米粒子嵌入 三. 纳米粒子在表面 一 . 纳米粒子 PDF 文件使用 "pdfFactory" 试用版本创建 www.fineprint.cn ÿ
一.纳米粒子 PDF文件使用"pdfFactory”试用版本创建ww.fineprint.cn
一 . 纳米粒子 PDF 文件使用 "pdfFactory" 试用版本创建 ÿwww.fineprint.cn
INSTITUTE OF PHYSICS PUBLISHING NANOTECHNOLOGY Nanotechnology 15(2004)467-472 PIL:S0957-448404)62779-6 Trapping of positrons at grain boundaries in nanoparticle systems V Thakur,S B Shrivastava and M K Rathore School of Studies in Physics,Vikram University.Ujjain(MP)-456010.India E-mail:vandanathakurl @rediffmail.com Abstract The positron annihilation in nanoparticle materials has been discussed in terms of the thermal diffusion of positrons at grain surfaces and trapping at the grain interfaces and interfacial defects.The diffusion trapping model has been applied to obtain the mean lifetime of positrons as a function of grain size and temperature and the S-parameter of the annihilation radiation as a function of grain size in Ag,Nb,Zn-Al and Zn-Al-Mg nanocrystallites.The calculated mean positron lifetimes have beencompared with the available experimental results. PDF文件使用"pdfFactory" 试用版本创建l.fineprint..cn
Abstract The positron annihilation in nanoparticle materials has been discussed in terms of the thermal diffusion of positrons at grain surfaces and trapping at the grain interfaces and interfacial defects. The diffusion trapping model has been applied to obtain the mean lifetime of positrons as a function of grain size and temperature and the S-parameter of the annihilation radiation as a function of grain size in Ag, Nb, Zn–Al and Zn–Al–Mg nanocrystallites. The calculated mean positron lifetimes have beencompared with the available experimental results. PDF 文件使用 "pdfFactory" 试用版本创建 Ìwww.fineprint.cn ÿÌ
280 Theory 260 Ag 240 802 220 200 180 160 15 20 25 30 35 Grain Size (nm) Comparison with the experimental results of the calculated mean positron lifetime in Ag nanocrystallites as a function of grain size PDF文件使用"pdfFactory”试用版本创建进.fineprint.cn
l Comparison with the experimental results of the calculated mean positron lifetime in Ag nanocrystallites as a function of grain size. PDF 文件使用 "pdfFactory" 试用版本创建 Ìwww.fineprint.cn ÿÌ