Land use change is a very complex process of evolution. On the basis of the principle of cellular automata, this article presents a kind of method that we can first mine state transition rule from historical map data, and then conduct forecast by virtue of Monte-Carlo method, achieving spatial...

The opal photonic crystals made of polystyrene microspheres with 155, 230, 270 or 410 nm in diameter were used to enhance upconversion (UC) emission of YF3:Yb3+, Er3+ nanoparticles, respectively. The red or green UC emission of YF3:Yb3+, Er3+ nanoparticles can be selectively enhanced when the...