The characteristics of leached particles from Eucalyptus urophydis wood chips and the leaching rules of micro/nano particles by u-sing the sorbitic-, supersonic-, freezing-, and microwave- extracting approaches were analyzed. The result showed that: (1) In sorbitic-extracting process, the volume and number of nano particles from fresh chips are more than those from old chips. However, the volume and number of the particles large than 91.3 nm from the fresh chips are less than those from old chips, and the extractive mass of micro and nano particles increases with the extracting time. (2) Super...