Fig. 1. Extinction properties of biological spores^[5]. (a)(b) Complex refractive index; (c) transmittance; (d) extinction proportion;(e) scattering proportion; (f) absorption proportion

Fig. 2. Complex refractive indexes of biomaterials in different bands^[32]. (a)(c) 0.25‒2.40 µm; (b)(d) 3‒15 µm

Fig. 3. Characteristic peaks of the biomaterials^[19]. (a) AN0616; (b) AO0622; (c) AP0627

Fig. 4. Scattered fraction of AN02 biomaterials^[37]

Fig. 5. Calculation flow of biomaterials extinction properties

Fig. 6. Extinction efficiency factor Q_ext of complex structured biological particles^[12]. (a) Typical particles; (b)‒(d) chain particles

Fig. 7. Extinction properties of monodisperse biological aggregated particles^[37]. (a) Aggregated particles models; (b) transmittance; (c) extinction cross-section

Fig. 8. Polydisperse biological aggregated particles models^[15]

Fig. 9. Factors affecting extinction properties of biological particles^[14]. (a) Porosity; (b) the number of original particles; (c) particle size distribution variance; (d) particle size distribution mean

Fig. 10. Mass extinction coefficient of different active biomaterials^[17]. (a)(c) BB0310; (b)(d) HJ0104

Fig. 11. The values of R2 and RMSEP corresponding to different models for the three biomaterials^[19]. (a)(b) AN0616; (c)(d) AO0622; (e)(f) AP0627

Fig. 12. Effect of wind speed on smoke screens^[23]. (a) Effect on average mass concentration; (b) effect on extinction area; (c) effect on extinction area change rate

Fig. 13. Effect of ground roughness on smoke screens^[23]. (a) Effect on average mass fraction concentration; (b) effect on extinction area; (c) effect on extinction area change rate

Fig. 14. Humidity growth model of biomaterials^[24]. (a)(b) Complex refractive index; (c) particle size

Fig. 15. SEM photos of different biomaterials^[12]. (a) AB0101; (b) AO0301; (c) LA0301; (d) BB0201

Fig. 16. IR spectra of different active biomaterials^[19]. (a) AN0616; (b) AO0622; (c) AP0627; (d)‒(i) the first derivative spectra

Fig. 17. Smoke box test system^［24］

Fig. 18. Extinction properties of aggregated particles^[37]. (a)(b) Aggregated particles models; (c) transmittance; (d) extinction cross-section

Fig. 19. Field test diagram

Fig. 20. Smoke screen images captured by infrared camera in outdoor field test at different time^[23]. (a) 0 s; (b) 10 s; (c) 20 s; (d) 30 s