The spectra analysis showed that porous silicon is the material with nano crystal structure, and photoluminescence of PS can be explained by the model of quantum restriction effect.

Combining the engineering example of Klnbrein Arch Dam 200 m high in Austria, aimed at restriction effect between foundation and arch dam, the 3-D finite element analysis has been carried out.

And compared with its counterpart, the characteristics on the condition of the airflow mixed with ultrasonic induced water mist, the restriction effect by water mist on plywood was discovered.