[1]Appraisal Centre for Environmental & Engineering of Tibet Lhasa 850000 China;
[2]Industry and Information Technology Department of Jiangsu Nanjing 210008 China;
[3]State Power Environmental Protection Research Institute Nanjing 210031 China;
Alleviation; Key areas; Key cities; Heating period; Prevention and control of air pollution; Blue sky defense; Energy solution;