Characteristics Evolution of Multiscale Structures in Deep Coal under Liquid Nitrogen Freeze-Thaw Cycles

Figure 8

Comparison of NMRI before and after freeze-thaw cycle.

(a) NMRI of HL sample before F-T

(b) NMRI of HL sample after F-T

(c) NMRI of SJZ sample before F-T

(d) NMRI of SJZ sample after F-T