ESR STUDY OF FREE RADICALS IN IRRADIATED POLYAMIDE-1010

Polyamide-1010 samples were irradiated in vacuum at room temperature by Cobalt-60 γ-rays. The free radicals formed in irradiation were studied by means of electron spin resonance (ESR)techniques.The ESRspectra consisted of a quartet and a superimposed singlet which were attributed to radical -CO-NH-CH-CH_2 and -CH_2-C=O, respectively. The effects of temperature and crystaUinity on the radicals were discussed and the mechanism for the production and decay of the radicals was also proposed.     

DC-SQUID磁强计数字控制系统

介绍一种新型的以MCU(微控制器)与FPGA(现场可编程门阵列)作为核心的DC-SQUID(直流电压-超导量子干涉器件)磁强计数字控制系统.该系统可以提供SQUID前端电路所需要的各种控制信号以及前端电路采样信号的放大、滤波等功能.使用MCU与FPGA实现系统的数字化控制、AD采集、LCD(液晶)实时波形显示与控制菜单显示等功能.MCU与FPGA的使用极大增强了系统的灵活性、可维护性与扩展性,方便了用户使用与设备升级.整个控制器已经完成并投入试验室使用.     

聚酰胺1010辐射效应的机理及结构

聚酰胺1010;非晶;结晶;辐射损伤;交联机理     

聚乙烯醇的强化辐射交联

通常γ-辐照裂解的聚乙烯醇(PVA)在N·N’-甲基丙烯酰胺(BAM)存在下可以辐射交联。BAM/PVA体系的辐射效应可大致依辐照剂量的增加划分为三个阶段:强化辐射交联为主区,强化辐射交联与辐射裂解相抵区和辐射裂解优势区。强化辐射交联区的溶胶分数S与辐照剂量D的关系可表示为: S=(1 (1/(1-K))D_g~(2=K))-(D_g/(1-K))D~(1-K) =A-BR~(1-K)式中,D_g为凝胶化剂量;K是与BAM含量相关的常数。     

铊膜DC－SQUID磁强计的噪声测量

ＤＣ－ＳＱＵＩＤｓ由铊膜制备．用两种方法测量了闭环ＤＣ－ＳＱＵＩＤ磁强计的噪声．研究了环境噪声对磁强计噪声测量的影响．