一、绪言在放射性活度绝对测量方法之一的4πβ做好源是一个十分重要的课题。减少源的自吸收和膜吸收都是决定测量准确度的重要因素。关于减小自吸收问题,以前有过很多研究,像沉淀法,胰岛素处理法,硅胶法等,还 I. Introduction 4πβ, one of the absolute measurement methods of radioactivity, is a very important subject. Reduce the source of self-absorption and membrane absorption are important factors in determining the accuracy of measurement. On the issue of reducing self-absorption, there have been many previous studies, such as precipitation method, insulin treatment method, silica gel method, etc.