Modern travel and communications technologies have made distance almost irrelevant to the diffusion of ideas and opportunities.
现代交通和通讯技术已使距离远近对于传播思想和获得机会几乎毫无影响。
2
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.
发现由于垂直扩散较强，最大浓度常于近源处发生，且向下风方浓度衰减较快。
3
The results showed that diffusion coefficient and diffusive distance increased with raising of negative substrate bias.