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Abstract Aiming at the reasonable width of the narrow coal pillar of a fully mechanized caving face and the safety support of roadway, taking the coal pillar in the section between 110503 and 110505 face of the Yushuling Coal mine as the research background, a model of the hard basic roof fracture structure of fully mechanized caving face is established through theoretical analysis, and the roadway with narrow coal pillar is analyzed mechanically. Combined with the geological conditions of the working face, it is concluded that the low‐stress area is less than 3.29 m. When the internal stress field of the low‐stress environment is considered in the roadway layout, the influence of mining and the essential roof hardness should be considered. The reasonable size of the narrow coal pillar is 3 ~ 6 m, thinking that the load borne by the coal pillar is less than the ultimate strength of the coal pillar. The limit equilibrium theory calculates that the reasonable width of a coal pillar is at least 4 m. The stress and displacement of coal pillars with different widths of 3, 4, 5 and 6 m are analyzed by numerical simulation, and the 4 m narrow coal pillars are simulated and verified. Field industrial tests show that coal pillar and roadway surrounding rock deformation are small under asymmetric surrounding rock control. The research results have been successfully applied to engineering practice and can provide a reference for the research method of narrow coal pillar width under a hard basic roof.

Cu2O doped with atomically dispersed Rh (Rh:Cu2O) is synthesized with a wet chemical method. It shows higher activity and faradaic efficiency at lower overpotential for reduction of CO2 to C2+ products, especially C2H4, than pristine Cu2O. We found that introducing Rh promotes CO2 adsorption, *CO hydrogenation to *CHO and their coupling to O*CCHO intermediates, which contributes to enhanced catalytic performance. [ABSTRACT FROM AUTHOR]

High-performance Cu catalysts were developed for the selective hydrogenation of γ-butyrolactone (GBL) to 1,4-butanediol (BDO). Among the various catalysts prepared by ammonia evaporation (AE) and impregnation (IM) methods with silica or MFI zeolite supports, the 5% Cu-SiO2-AE catalyst was the best one. It exhibited 95% selectivity for BDO and 71% conversion of GBL after 2–8 h reaction at 200 °C and 4 MPa H2, with high stability in five-cycle runs. Comprehensive characterizations showed that the AE method favored generating nano Cu particles with an average size of 2.9 nm on the 5% Cu-SiO2-AE catalyst. The silica support derived from a sol demonstrated an advantage over the MFI zeolite in the preparation of a highly dispersed and stable Cu catalyst, in view of its anti-sintering and robust composition of Cu0, Cu+, and Cu2+ in the cycling operation. The reaction pathways for GBL to BDO over the Cu catalysts were found to commonly involve reversible reactions of hydrogenation and dehydrogenation, along with subsequent dehydration to form THF. The high performance of the Cu catalysts in the conversion of GBL to BDO was attributed to the high dispersion of Cu, the presence of stable active sites, and fewer strong acid sites in the catalyst. [ABSTRACT FROM AUTHOR]

[Objective] Simulating the change of runoff and sediment changes in the watershed under the influence of land use and climate in the future is conducive to making suitable management plans. [Methods] Based on land use and meteorological data, combined with CMIP6 climate model data, PLUS model and SWAT model, the temporal and spatial changes of land use and runoff and sediment under different climate scenarios in 2030 were quantitatively simulated. [Results] (1) The SWAT model exhibited good accuracy in monthly scale in simulation of Minjiang River Basin, in which the R² and NSE (Nash-Sutcliffe Efficiency) ranged from 0.80 to 0.95 and 0.75 to 0.91, respectively. The R² and NSE ranged from 0.75 to 0.98 and 0.64 to 0.94 respectively. (2) Using the land use data of 2020 to evaluate the accuracy of the PLUS model, the Kappa coefficient was 0.77, and the simulated construction land and cultivated land in the Minjiang River Basin in 2030 would increase by 325.64 km² and 1 157.51 km², respectively. (3) Under the SSP2-4.5 and SSP5-8.5 scenarios, the average precipitation in 2025-2035 would increase by 0.15% and 2.18%, and the average annual temperature would increase by 0.23 and 0.62 °C, respectively. (4) In the low carbon and high carbon scenarios, only land use change led to an increase of 0.08% and 0.07% in annual mean runoff, and an increase f 0.24% and decreased of 0.05% in annual mean sediment transport, respectively, compared with the baseline period. Compared with the baseline period, the mean annual runoff decreased by 4.76 % and 4.11%, and the mean annual sediment transport increased by 18.12% and 0.13%, respectively. The combined effects of land use and climate resulted in a decrease of 4.57% and 3.93% in annual average runoff and an increase of 8.28% and 0.33% in annual average sediment transport compared with the base period, respectively. (5) Under the scenario of future climate and land use comprehensive change, the areas with higher and larger increase in surface runoff and sediment yield were concentrated in the northwestern of the basin centered on Shaowu City in Nanping and the southwest of the basin centered on Jiangle County in Sanming. [Conclusion] These research results provide some reference for the reasonable development and construction of Minjiang River basin in the future. [ABSTRACT FROM AUTHOR]

Poverty is a common challenge faced by human beings. China's Targeted Poverty Alleviation (TPA) policy provides the international community with a Chinese solution to poverty governance. Based on the goal of China's TPA policy of "Two No Worries, Three Guarantees," this paper selects appropriate indicators to evaluate the implementation effect of China's TPA policy since 2013. The results show that there are significant differences between poor families and non-poor families in food consumption, clothing consumption, education, and housing. After the implementation of the TPA policy, the gap between poor families and non-poor families has been significantly reduced. However, from the perspective of per capita household consumption, there is still a certain gap between poor families and non-poor families, and it is still necessary to maintain the continuity to further improve the living standards of low-income families. JEL Classification: I32 [ABSTRACT FROM AUTHOR]