【摘要】 本文研究了熔融结晶聚乙烯的不同结晶度和不同辐射剂量对正电子湮没特性的影响。结果表明,正子素(Ps)对聚合物内部的分子序列结构的变化,特别是对分子链有序度的变化非常敏感。更多还原

【Abstract】 Using a one-dimensional positron annihilation angular correlation spectromter (FWHM= 0.33mrad) and a positron lifetime spectrometer (FWHM=0.305ns), we have performed the measurements on angular correlation and positron lifetime spectra of the gamma rays produced by positron annihilation in a series of melt-crystalline polyethylene with different crystallinities and those irradiated by 60Co with different doses. The relation between molecular structure and positron annihilation parameters is discussed.更多还原