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In order to increase the content of mineral admixtures in cement, this study proposes a method for preparing a high-volume mineral admixture cementitious material (HMAC) using superfine cement as a reverse filling material. Firstly, superfine cement is prepared through mechanical grinding. Then, the activity of mineral admixtures (such as slag and fly ash) is enhanced by mechanical grinding, sulfate activation, and alkali activation methods. Meanwhile, the evolution of HMCM from microstructure to macroscopic mechanical behavior is studied by combining a laser particle size analyzer and a scanning electron microscope. Furthermore, the reverse filling mechanism of superfine cement on mineral admixtures under different activation conditions is proposed. Results show that superfine cement can largely improve the utilization rate of cement clinker and the compressive strength of cementitious materials. In the condition that the compressive strength is not lower than that of the control group (without mineral admixture), the content of mineral admixture can be increased to 50%, 70%, and 90% after mechanical grinding, sulfate activation, and alkali activation, respectively. Analysis indicates that the reverse filling effect of superfine cement is the main reason for improving the density of the HMCM.

How to reduce the rising carbon (C) in the atmosphere by enhancing forest soil C-holding capacity requires further research. Forest density via thinning has long been studied for this reason. However, how changes in density affect soil C sequestration is still uncertain for many other factors also affect soil C in open forest ecosystems. To measure the effect of thinning on soil organic carbon (SOC) stock relative to other contributing factors, we selected 12 25 × 25 m plots, and applied a series of thinning treatments: CK (control plots; 2173 ± 12 trees ha−1, which was how all plots started), LT (light thinning; 1834 ± 12 trees ha−1), MT (moderate thinning; 1418 ± 7 trees ha−1) and HT (heavy thinning; 1089 ± 13 trees ha−1). We measured the SOC stocks (kg C m−2) for 11 seasons crossing three years. In addition, soils of the four treatment plots (0–50 cm soil depth, 5 layers, 10 cm per layer) were collected once per season, and then the samples were incubated for 56 days before measuring their cumulate mineralized carbon (CMC). The temperature at 10 cm underground was measured every 60 min throughout two years. The active carbon (DOC (dissolved organic C) and MBC (microbial biomass C)) stocks were also measured. We found that soil in MT plots held more C overall, with more active carbon per unit of SOC. Soil temperatures were affected by the thinning as well as the C and N (nitrogen) stock. Soil temperatures and C, N stock alike rose from CK levels and peaked in MT, before decreasing in HT. However, SOC mineralization rate (mineralized-C) was reduced in MT across seasons, and mineralized-C varied seasonally. Soil C and N stocks were enhanced in MT plots, partly due to the increased soil temperatures and the reduced mineralized-C.