Beijing, Sept. 4 -- Daqing Branch Heilongjiang acad Sciences has been granted a patent for Preservative Mixing Device for Production of Ghee Moisturizer. This invention was developed by Tian Yuan, Zhang Zhiguo, Dong Yan, Lausan Tatsukei, Shi Yu, Gao Baochang, Zhang Jingru, Zhang Xu, Zhang Xiaoyan, Bian Jing, Zhang Zhenghai, Wei ..