Covalent organic frameworks (COFs) have gained considerable attention due to their highly conjugated π-skeletons, rendering them promising candidates for the design of light-emitting materials. In this study, we present two vinylene-linked COFs, namely, VL-COF-1 and VL-COF-2, which were synthesized through the Knoevenagel condensation of 2,4,6-trimethyl-1,3,5-triazine with terephthalaldehyde or 4,4′-biphenyldicarboxaldehyde. Both VL-COF-1 and VL-COF-2 exhibited excellent chemical and thermal stability. The presence of vinylene linkages between the constituent building blocks in these COFs resulted in broad excitation and emission properties. Remarkably, the designed VL-COFs demonstrated bright emission, fast fluorescence decay, and high stability, making them highly attractive for optoelectronic applications. To assess the potential of these VL-COFs in practical devices, we fabricated white-light-emitting diodes (WLEDs) coated with VL-COF-1 and VL-COF-2. Notably, the WLEDs coated with VL-COF-1 achieved high-quality white light emission, closely approximating standard white light. The promising performance of VL-COF-coated WLEDs suggests the feasibility of utilizing COF materials for stable and efficient lighting applications.

The introduction of new intelligent components in the power system produces more harmonics, and UPFC can adjust them well. For improving the effectiveness of performance parameters of the power system, a reactive power optimization method based on particle swarm optimization considering UPFC is proposed. Through the paper, the energy parameter with UPFC is calculated under the way of the power injection model, and the objective function is to minimize the energy loss in the system. On this basis, reactive power optimization is realized by particle swarm optimization. Under the background of the simulation of the IEEE9 bus, the results of system parameters before and after using particle swarm optimization in UPFC are analyzed. It is found that the proposed method has a good advantage to improve the system network loss and optimize the system quality, which has good practical value.

Methylammonium lead halide perovskites are well-known having a poor stability towards moisture. Water causes degradation of ionic perovskites and weaken the optical and electronic performance of perovskite-based devices. Main strategies to improve moisture stability are compositional engineering, surface engineering and matrix encapsulation. Herein, encapsulation strategy is implemented through screening a polymer matrix, a room-temperature vulcanized silicone rubber (RTV-2). Owing to the positive effect of moderate water on the performance of perovskites, the obtained MAPbBr 3 /RTV-2 composite film is processed with water post-treatment to undergo surface engineering. The composite film achieves a remarkable 8-fold fluorescence enhancement. Luminous efficiency of the film loaded on a 380 nm chip is improved from 51.4 lm/W to 135.37 lm/W. The flexible MAPbBr 3 /RTV-2 film responds sensitively under X-ray irradiation. Its detection limit is down to 12 nGy air s -1 , 400 times lower than the regular dosage in X-ray diagnostics (5.5 μGy s -1 ). These results provide guidance to design perovskite-based devices with bright luminescence and excellent flexibility to be potential in wearable X-ray detectors for dose monitoring.