一、引言利用放射性方法做土密度和湿度的测定,自1950年以后,许多国家都在进行研究,但是直到如今它还没有普遍地被人使用,用放射性物质来测定土的密度和湿度的方法,不但简便,而且比较准确,可是要达到普遍使用,首先得具备以下条件:1.本国要有廉价 I. INTRODUCTION The use of radioactive methods for the determination of soil densities and humidities has been studied in many countries since 1950, but until now it has not yet been used universally to determine the density and humidity of soils using radioactive substances , Not only easy, but more accurate, but to achieve universal use, first of all have to meet the following conditions: 1. The country should have cheap