On Development Process of Urban Environment Governance Abroad and China
jiang ai-lin1; zhong jing-tao2; zhang zhi-hui3 (institute of all china federation of trade unions; beijing 100865; territory resource department beijing 100812; chinese academy of social sciences; beijing 100102; china)
Search Power System Fault Section Based on Petri Net
hou rong-sheng1; wang cai-gan2 (1.jiangxi vocational and technical college of electricity; nanchang 330032; 2.nanchang power company supply nanchang 330096; china)