Diffusion scatters light, essentially making the light source broader and therefore softer.
运用漫散射分散光线的实质还是使光源变广，从而达到柔化光线的目的。
2
The model consists of a single advection? Diffusion equation with a source term.
此模型由一个单一的具有源项的对流扩散方程组成。
3
It is found that the maximum concentration often occurs near source through intensive vertical diffusion, and the values of concentration decrease with the distance downwind rather rapidly.