It occurs when temperature differs at different depths or altitudes so that one layer is a drastically different temperature and density
Partners 14 Chinese cities (Anshan, Beijing, Changchun, Haerbin, Hangzhou, Kelamayi, Lanzhou, Luoyang, Nanchang, Qingdao, Shenyang, Shenzhen, Tangshan, and Tianjin) China CDC World Health Organization US Centers for Disease Control and Prevention Emory University International Union Against Tuberculosis and Lung Disease Main Conclusions Current smoking prevalence among males ranged from 32.7% to 44.8%
Stephens [Contents] Puzzle No
Data are represented as the mean SEM and * indicates data are statistically significant difference with the controls