Environmental hormone existing in environment can interfere with biological system or process to abnormal effects.It can interfere with the hormone in organism,damage human reproductive function,or lead to tumors,and so on.So it makes a serious threat to human health and survival.The fundamental countermeasure of preventing environmental hormone is to stop its source.

DBDMH(1,3-Dibromo-5,5-dimethylhydantoin)is a new environment-friendly antibacterial disinfectant agent which is high performance,broad-spectrum and low-residue.This paper introduces the structure,property,antibacterial mechanism,producing process and application of DBDMH.

Scientists have paid much attention to carnitine since it was discovered more than one hundred years ago.More and more consumers favor the drugs and health products which contain carnitine.This paper mainly introduces its origin,biological functions,synthetic methods and application.

Review the construction and development of chemistry didactics discipline in China over the recent more than fifties years.Discusses and reflects on it dividing into three stages in accordance with time,and puts forward some opinions and suggestions.