Nitrogen hybridization is an attractive way to enhance the wettability and electric conductivity of porous carbon, which increases the capacitance of carbon-based supercapacitor, however, there is lack of low-cost methods to prepare the nitrogen-doped porous carbon materials. Herein, a novel facile nitrogen-containing bio-phenolic resin was synthesized by polymerization of the carbamate bio-oil, Phenol and paraformaldehyde. As a precursor of nitrogen-doped porous carbon, the nitrogen-containing bio-phenol resin was activated by the one-step molten-salt method. The resultant nitrogen-doped porous carbon showed a high specific surface area up to 1401 m²·g⁻¹. As a supercapacitor electrode, the nitrogen-doped porous carbons showed specific capacitance of 159 F·g⁻¹ at 0.5 A·g⁻¹. It also exhibited high cyclic stability with 94.8% retention of the initial specific capacitance over 1000 charge-discharge cycles at 1.0 A·g⁻¹. The results suggest that these nitrogen-containing bio-phenol resin provide a new source of nitrogen-doped porous carbon for high-performance supercapacitor electrodes.

The WC and high chromium cast iron (HCCI) welded layers were prepared on Q235 low carbon steel by hardfacing technique in order to improve high-temperature performance. The microstructure and mechanical properties of the welded layer were investigated. It was found that Fe₃W₃C is the major strengthening phase of the WC welded layer. Furthermore, a high-temperature three-body abrasive wear experiment was designed and conducted on the welded layers. The results show that the wear resistance of the WC welded layer was much better than that of the HCCI welded layer at both room and high temperatures. During the high-temperature abrasive wear process, the Fe₃W₃C phase can effectively strengthen the matrix and hence, contribute to improved wear resistance.