n.图心；矩心；重心
A self-adaptive feature extraction method based on power spectral centroid is proposed. 摘要提出一种基于功率谱重心的自适应特征信息提取方法。
If this load centroid is behind the elastic axis of the wing structure, then a nose-down twist of the main wing surface results. 如果该载荷重心在机翼结构弹性轴之后，则引起主机翼表面前端向下的扭转。
