Fig. 3. Simulated growth of newly formed particles. The left panel shows different diameters of the growing mode during the model experiment, and the right panel shows the corresponding number (N), surface area (A), and mass (M) concentrations. The model inputs are: J_1.5 = 200 cm⁻³ s⁻¹, duration of NPF = 5 h, GR = 5 nm h⁻¹, CS = 0.015 s⁻¹ and CS/GR = 10.8 nm⁻¹, which all are within the values observed in Beijing.¹⁵.