In materials marked by low thermal diffusivity, the absorption is good . 热扩散率低的物质吸收性好。
The thermal conductivities and thermal diffusivities of the material must be known . 必须知道各种材料的热导率和热扩散率。
In heterogeneous anisotropic materials the thermal diffusivity cannot be described by a single number . 在各向异性的非均质物质中,热扩散率不可能用一个简单数字来表达。
These kinds of measurements are necessary for determinations of thermal diffusivities from the thermal conductivity and densities . 根据热导率和密度确定热扩散率必须进行这种测量。
Limiting the extraction of great amount of heat from the underground even more is the low thermal conductivity and low thermal diffusivity of rocks . 由于岩石的热导率和热扩散率都比较低,更加限制了地下热能的大量抽取。