Effects of different ecological restoration methods on the soil physicochemical properties and vegetation community characteristics of the Baotou light rare earth tailings pond in Inner Mongolia, China.

This study investigated the soil physicochemical properties and vegetation community characteristics of the Baotou light rare earth tailings pond after 10 years of aggregate spray seeding ecological restoration (S1) and ordinary soil spray seeding ecological restoration (S2), and the naturally restored dam slope area without human intervention (S3). The results showed that the vegetation community of S1 was dominated by Caragana korshinskii Kom, and its importance and abundance values were 0.40 and 38.4, respectively, while the vegetation communities of S2 and S3 mainly comprised herbaceous plants. Additionally, the vegetation biomass of S1 was significantly higher than that of S2 and S3 by 215.20% and 1345.76%, respectively, and the vegetation diversity index of S1 was the highest among the three treatment groups. The soil porosity (SP), water content (W), electrical conductivity (EC), and available K were significantly improved in S1, while soil bulk density (BD) was significantly reduced compared with that of S2 and S3. In addition, redundancy analysis revealed that SP, EC, W, and K positively correlate with the biomass, Shannon, Pielou, Simpson, and Marglef indices. Principal component analysis further showed that the comprehensive score of S1 (0.983) was higher than that of S2 (- 0.261) and S3 (- 0.648). Collectively, these findings indicate that appropriate ecological restoration can improve soil structure and vegetation community characteristics, thereby accelerating vegetation restoration, ultimately increasing the stability of the ecosystem.

Fabrication and optical properties of Pr3+-doped Ba (Sn, Zr, Mg, Ta) O3 transparent ceramic phosphor.

To the best of our knowledge, we have successfully fabricated a novel transparent ceramic phosphor of Pr3+-doped Ba (Sn, Zr, Mg, Ta) O3 (Pr3+:BMT) via a high-temperature solid-state reaction method. The in-line transmittance of 59% at 650 nm was measured. The Pr3+:BMT ceramic phosphor can emit 650 nm red light excited by 447 nm blue light. The ceramic phosphor can still work at 383 K. The activation energy was calculated to be 0.17 eV. The efficiency of the ceramic phosphor is twice that of its powder phosphor. The Pr3+:BMT ceramic phosphor showed good thermal stability and enhanced the chromaticity of its white LEDs, which make it a promising red phosphor for lighting.