This paper introduces the concept of endocrine disrupting chemicals-environmental hormones, their origin and perniciousness and the proposal of solving this problem.

Nano-materials and nano-techniques, the most attractive fields in the current material area, will be the leading echniques in the first 20 years of the century. The applications of nano-materials and nano-techniques are almost involved in every field of modern industry.This paper mainly describes the applications of nano-materials and nano-techniques in vairous fields.

This study is focused on the mental models of atoms and molecules of secindary school students. The semistructured interviewing technique is employed and the sample of interviewees includes third and fourth year secondary school students and the first year university students. The results of this study are analyzed in two aspects: students.understandings about the atomic models and their discourse descriptions of atoms and molecules. Some discussions on the results are made in the end of this paper.