中文摘要：

提出了通过实时测量扩散过程中多孔介质浮重变化,直接测定有效扩散系数的方法.首先建立了联系有效扩散系数和试件浮重变化的数学模型,并求出了该模型的解析解;利用非线性超定方程组优化求解的方法,结合问题的解析解和实测数据,反求出模型中的参数,有效扩散系数和边界层传质系数.用上述参数预测的试件浮重变化与实测浮重变化相差很小.表明该方法的实用性和可靠性.

英文摘要：

A new way to determine the effective diffusivity of porous media has been developed by measuring the variation of buoyed weight. A mathematical model connecting the effective diffusivity and buoyed weight of a sample was constructed and the analytical solution of the model was attained. The effective diffusivity and mass transfer coefficient in boundary layer were deduced by nonlinear least square approximation, comparing the analytical solution with the experimental data. The difference between the predicted and measured changes in buoyed weight of a sample was quite small, indicating that the model has feasibility and reliability.