Search

In this work, the decorated polyborosiloxane (MAPBS) with phosphorus-nitrogen components was first synthesized via a hydrolysis-condensation reaction and thus incorporated the MAPBS filler into epoxy resin (EP) to fabricate composites by a simple blending method. It could be found that the MAPBS with epoxy groups showed a good dispersion level in the EP matrix, endowing EP composites with superior flame retardancy and mechanical properties. Thanks to the combination of phosphorus-, nitrogen-, boron-, and silica-containing units in MAPBS filler, the addition of 6 wt% MAPBS made EP achieve significantly improved limiting oxygen index (25.2 ± 0.5%) and UL-94 rating (V1). Meanwhile, cone calorimeter test results revealed that the peak heat release rate (PHRR), total heat release (THR), and total smoke production (TSP) of the EP-MAPBS6 composite were reduced by 31%, 62%, and 67%, respectively, as compared to the pure EP. In addition, the MAPBS6 composite exhibited balanced tensile strength (105.1 MPa) and elongation at break (87.6%) among the prepared samples. The present work provides an effective strategy to fabricate EP composites with improved comprehensive performances. [ABSTRACT FROM AUTHOR]

Corrosion defects will increase the risk of power equipment failure, which will directly affect the stable operation of power systems. Although existing methods can detect the corrosion of equipment, these methods are often poor in real-time. This study presents a two-stage detection approach that combines YOLOv8 and DDRNet to achieve real-time and precise corrosion area localization. In the first stage, the YOLOv8 network is used to identify and locate substation equipment, and the detected ROI areas are passed to the DDRNet network in the second stage for semantic segmentation. To enhance the performance of both YOLOv8 and DDRNet, a multi-head attention block is integrated into their algorithms. Additionally, to address the challenge posed by the scarcity of corrosion defect samples, this study augmented the dataset using the cut-copy-paste method. Experimental results indicate that the improved YOLOv8 and DDRNet, incorporating the multi-head attention block, boost the mAP and mIoU by 5.8 and 9.7, respectively, when compared to the original method on our self-built dataset. These findings also validate the effectiveness of our data augmentation technique in enhancing the model's detection accuracy for corrosion categories. Ultimately, the effectiveness of the proposed two-stage detection method in the real-time detection of substation equipment corrosion defects is verified, and it is 48.7% faster than the one-stage method. [ABSTRACT FROM AUTHOR]

Although NiSx has a high storage advantage in ion battery as the anode material, the shortcomings such as poor conductivity and volume expansion seriously affect the performance. In this work, NiSx nanoparticles with an S/N-doped carbon layer (NiSx@S/N–C) are prepared by a simple hydrothermal reaction combined with heat treatment. At 2 A g−1, the discharge-specific capacity of the NiSx@S/N–C electrode can achieve at 609 mAh g−1 at the 400th cycle for lithium-ion batteries. Meanwhile, it shows the 270 mAh g−1 discharge capacity in the initial cycle and obtains a high specific capacity of 232 mAh g−1 after 250 cycles at 0.5 A g−1 for Na storage. In this research, a simple and reliable method is adopted to improve the capacity and performance of transition metal sulfide. [ABSTRACT FROM AUTHOR]

The cracking and reasons for aging of silicone rubber current transformer insulation sheath from a 500 kV substation were investigated. Chemical characteristics including attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, mechanical properties, and thermo gravimetric analysis (TGA) have been performed on the external surface and internal parts of the silicone rubber CT insulation sheath. The FTIR results indicated that the external surface of the silicone rubber CT insulation sheath suffered from more serious aging than the inner, fracture of the side chain (Si-C bond) was much more than the backbone (Si-O bond). Mechanical test results revealed that the tensile strengths of the external surface parts of the silicone rubber CT insulation sheath were lower than those of the internal parts. TG analysis data indicated thatTonsetdropped nearly 50°C for the external surface of the silicone rubber CT insulation sheath. All the chemical characteristics have showed that the external surface material of the silicone rubber CT insulation sheath had been serious aging. Our work suggested a facile and effective method for evaluating the aging state of the silicone rubber insulation sheath in the electric power field from the perspective of chemical. [ABSTRACT FROM AUTHOR]