TY - JOUR A1 - Pathak, R. K. A1 - Wu, W. S. A1 - Wang, T. T1 - Summertime PM2.5 ionic species in four major cities of China: nitrate formation in an ammonia-deficient atmosphere JO - Atmos. Chem. Phys. J1 - ACP VL - 9 IS - 5 SP - 1711 EP - 1722 Y1 - 2009/03/06 PB - Copernicus Publications SN - 1680-7324 UR - http://www.atmos-chem-phys.net/9/1711/2009/ L1 - http://www.atmos-chem-phys.net/9/1711/2009/acp-9-1711-2009.pdf DO - 10.5194/acp-9-1711-2009 ER -