Spatial Variation of Negative Air Ion Concentration in Different Biotopes in Henan Province
WEI Shu-yun;LIU Wen-xia;WU Ming-zuo;SHEN Lian-feng;WANG Jiang-yan;SHEN Chong;WANG Yao-ming;College of Forestry;Henan Agriculture University;Banan Branch of Chongqing Public Security Bureau;School of Mechanical and Electrical Engineering;Henan Institute of Science and Techlology;Laojunshan State Forest Farm of Luanchuan County;