摘要
在加热和冷却过程中,分别测量了EBBA样品的正电子湮没寿命和差示扫描量热(DSC)曲线。结果表明短寿命(τ_S)基本不变,而长寿命(τ_L)和强度(I_L)明显地变化;在加热和冷却过程中向列相——晶体转变温度Tc(K)不同。这一现象可以用ORE模型和液晶在相变过程的微观结构变化来解释。
The positron lifetime and DSC measurements have been made for EBBA samples in the heating and cooling cycles. The experimental results show that the shorter lifetime (τs) is essentially independent of temperature while the longer lifetime (τL) and the intensity (IL) change obviously. In the heating and cooling cycles the transition temperatures are different. This phenomenon has been explained by using the ORE model and the change of micro-structure of liquid crystal during the phase transition.
出处
《核技术》
CAS
CSCD
北大核心
1991年第9期532-534,共3页
Nuclear Techniques
关键词
液晶
正电子湮没
相变
Liquid crystal Positron annihilation Phase transition Molecular ordering
