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Robinia pseudoacacia (R. pseudoacacia) is a well reported plant species for heavy metal phytoremediation, and it was capable to improve Cd uptake efficiency after inoculated with plant growth promoting endophytes. However, the knowledge on R. pseudoacacia associated endophytes in field condition and the relationship between these microbial communities and heavy metal uptake capacities are still scarce. In this study, the characteristics of heavy metal bioaccumulation and translocation in R. pseudoacacia, and the structure and function of its endophytic bacterial communities were revealed. The results showed that heavy metal pollution made microbes more sensitive to the environment as the diversity (Shannon) of endophyte community decreased but the abundance (Chao) increased. Redundancy analysis (RDA) also showed that heavy metals were the key factor affecting the composition of endophyte. In the co-occurrence network, 27 keystone taxa mainly from Actinobacteria, Proteobacteria and Firmicutes occupied the dominant niches, among which 16 OTUs mainly from lactobacillus, bacteroides, staphylococcus, methylorubrum and bifidobacterium were positively related to bioaccumulation and translocation of Cd, Cu, Pb and Zn. Besides, heavy metal stress enhanced the functional adaptability of endophytic bacteria community. Related predicted genes were enriched in immune response, physiological metabolism pathway and stress-resistant enzyme synthesis. This study showed that heavy metal stress enhanced the structural and functional adaptability of endophyte community and keystone taxa played significant role in improving the efficiency of phytoremediation.

Hyperspectral images (HSIs) have rich spectral information, but the various noises generated during the imaging process destroy the visual quality of images and lower the application precision. Therefore, it's crucial to denoise HSI for making better use of it. At present, low-rank-based methods have shown potential in mixture noises removal. While their limitations in rank function approximation, which affects the description of the low rank property in HSI, still need to be broken through. This paper puts forward a bilinear low rank matrix factorization (BLRMF) HSI denoising method, where the bi-nuclear quasi-norm is employed for constraining the low rank characteristic in HSI. The bi-nuclear quasi-norm is a closer approximation to the rank function and can be calculated by the nuclear norms of two smaller factor matrices, which respectively describe the spatial low rank and the spectral low rank. The Alternating Direction Method of Multipliers (ADMM) is employed for solving the optimization problem. A large number of experiments on HSI denoising are conducted to verify the superiority of the BLRMF over the mainstream denoising methods.

Pr3+-doped LaMgAl11O19 (LMA) crystals have been successfully grown by the Czochralski method with different concentrations ranging from 0.5 to 10.0 mol%. Crystalline quality and the phonon energy were determined by X-ray diffraction and Raman measurements. Spectroscopic parameters based on absorption spectra were systematically calculated using the modified Judd-Ofelt theory. The fluorescence results indicate a large dependence on the factor of doping concentration. The 3P0→3F2 transition red laser channel has the largest emission cross section at 10.7 × 10−20 cm2 for 5.0 mol% Pr:LMA. The fluorescence lifetime of the 3P0 energy level is determined to be 32.6 μs at room temperature with a quantum efficiency of 82.9% for a 5.0 mol% Pr3+-doped sample. The overall spectral properties confirm that Pr:LMA is a promising candidate for visible laser operation.