Field Study on Correlation between CO<sub>2</sub> Concentration and Surface Soil CO<sub>2</sub> Flux in Closed Coal Mine Goaf.

ACS Omega · 2019 · PMC6682097 · PMID 31460328

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a decreasing trendno p-value reported

When the region exceeds 2 m in depth, the CO 2 concentration has a decreasing trend with increasing depth, as shown in Figure 13 .

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