No abstract

Hydrothermal treatment was adopted to address the wear and corrosion problems that are common when using magnesium alloys. Films consisting of magnesium hydroxide and Mg-Al layered double hydroxide (LDH) were formed on the AZ31 Mg alloy via hydrothermal treatment in deionised water and an alkaline solution containing aluminium ions, respectively. It was found that the presence of aluminium and hydroxyl ions in the hydrothermal solution significantly promoted LDH formation. Performance testing for the obtained films showed that their tribological properties and corrosion resistance were significantly improved compared to those of the Mg alloy. Furthermore, the film prepared in an alkaline solution containing aluminium ions exhibited a more stable friction coefficient, a lower wear rate, and a superior corrosion resistance, which were associated with the increased LDH content. This study, therefore, presents a facile and promising method for the development of highly wear-resistant and anti-corrosion surfaces for Mg alloys.

The accurate condition assessment of wind turbines greatly influences the refined asset management and maintenance scheduling of wind farms. To address the challenges of existing assessment methods in selecting the reliability value and determining wind turbine status levels of being in transition, this study proposes a wind turbine condition evaluation method based on asymmetric proximity. Firstly, the state evaluation index system consisting of the wind turbine performance and output state indices is constructed, and the weighting factors are calculated comprehensively by integrating the subjective and objective weights. Then, the membership function of the index layer is established based on the set pair analysis, and the membership of the target layer is deduced by the weighted average operator. Finally, the proximity degrees between status levels and target membership degrees are calculated, and the wind turbine state is determined based on the proximity principle. Case studies demonstrate that the accuracy rate of the proposed method is up to 97%, which is 6% and 8% higher than the maximum membership principle and the reliability criterion, respectively.

No abstract

No abstract