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Numerous efforts have been made to fabricate Li2TiO3 tritium breeding ceramics with satisfactory density and mechanical strength while maintaining a fine grain structure. In this study, high‐energy ball milling was performed to promote grain refinement and amorphization of TiO2 and Li2CO3 powders, thereby preparing Li2TiO3 ceramic at a reduced sintering temperature. In the presence of high‐energy ball milling, powder mixtures with particle sizes of 24–29 nm were obtained, and the formation of β‐Li2TiO3 occurred at 400°C. The relative density and crushing load of Li2TiO3 ceramic pebbles improved as the ball‐to‐powder ratio and milling time increased. The Li2TiO3 ceramic pebbles sintered at 900°C exhibited a tiny grain size, satisfactory relative density (89%), and excellent crushing load (121 ± 13 N). The results also demonstrated that Li2TiO3 ceramic possessed the maximum thermal conductivity and ionic conductivity under the conditions of a 20:1 ball‐to‐powder ratio and 20 h milling time, that is, 5.028 W/m·K and 1.87×10−2 S/m at room temperature. Overall, the high‐energy ball milling process has shown advantages in the fabrication of tritium breeding ceramics with fine‐grained structure and excellent comprehensive performance. [ABSTRACT FROM AUTHOR]

Self-powered full-spectrum photodetectors (PDs) offer numerous advantages, such as broad application fields, high precision, efficiency, and multi-functionality, which represent a highly promising and potentially valuable class of detectors for future development. However, insensitive response to solar-blind ultraviolet (UV) and complex and expensive preparation processes greatly limit their performance and practical application. In this study, a self-powered full-spectrum Bi2Se3/a-Ga2O3/p-Si heterojunction PD with high sensitivity for solar-blind UV band prepared by a simple and low-cost two-step synthesis method is presented. Experiments results reveal that the developed PD has an excellent performance, such as high sensitivity from 200 to 850 nm, and a responsivity of 1.38 mA/W as well as a detectivity of 3.22 × 1010 Jones under 254 nm light at zero bias. Additionally, the unencapsulated device displays exceptional stability and imaging capabilities. It is expected that Bi2Se3/a-Ga2O3/p-Si heterojunction PD with a simple and low-cost synthesis method has great potential for self-powered full-spectrum photodetectors. [ABSTRACT FROM AUTHOR]

In order to explore the reasonable coal pillar size of the backfilling working face, taking Shandong Yineng Coal Mine as the engineering background, a structural mechanics model of “backfilling body-coal pillar-backfilling body” was constructed. The damage level is determined by studying the internal failure conditions under different sizes of coal pillar, and the bearing characteristics of coal pillar in different sizes, zones and grades are proposed. The vertical stress, plastic development characteristics and deformation of coal pillar at different scales of 10 m, 6 m, 3 m and 1 m are simulated and analyzed by using UDEC software. The simulation shows that the vertical stress distribution decreases with the decrease of width, the minimum reaches 16.5 MPa, the plastic zone increases with the decrease of coal pillar size, the deformation of coal pillar increases with the decrease of coal pillar width, and reaches the minimum deformation at the range of 3-6 m; according to the “quadrant method” of coal pillar stress and deformation characteristics, the coal pillars stability of different widths was explored. Combined with the safety and economic factors of the mine, the reasonable width of small coal pillar under the conditions of superhigh water backfilling mining is determined to be 3 m. It is proposed to maintain the stability and sealing of small coal pillar by grouting and plugging, anchor bolt and mesh support technology, and determine the grouting process, materials, timing, pressure and other parameters, which could provide an effective guarantee for the safe and high recovery rate for backfilling mining with deep buried depth.