Then this paper studied the effect of diffusion coefficient on concentration distribution and the conditions of substitution with numerical dispersion for physical diffusion.
通过将该半解析解与忽略扩散的数值解进行对比分析，讨论了数值弥散代替物理扩散的条件。
2
Destructive techniques are techniques in which the sample is decomposed by a reagent and then the concentration of the element in the aqueous extract determined by a physical technique.
破坏性技术是将样本溶解于溶剂，然后通过物理方法分析元素浓度的技术。
3
When you observe your abdomen rise and fall, a physical process, and your concentration becomes deep enough, you begin to realize the rising and falling movements very clearly in their true nature.