Figure 2

TEM images and EDS spectra of individual primary particles from the combustion of wheat straw. (a) Gel-like OM internally mixed with K2SO4/soot; (b) Gel-like OM without any inclusion; (c) One irregular particle comprised of soot, K2SO4, and OM coating. The combustion phase was a mixture of smoldering and flaming phases. The insets show the electron diffraction patterns of K2SO4 with different K/S ratio. The corresponding EDS spectra are indicated by the number in square brackets.