<正>设计了一种锯链锯切木材时可实时动态测量主切削力、进给力和侧向力的八角环式三向测力传感器。通过对主切削力和进给力方向的标定，分析研究贴片位置对被测方向灵敏度、非线性度的影响，以及对非被测方向交叉灵敏度的影响。修改进给力方向的贴片位置，使交叉灵敏度由3.2×10-6N11下降到4.27×10-7N-1，进给力测试系统的非线性度由原来的7.8%下降到0.025%。主切削力、进给力、侧向力等各测力方向的灵敏度分别为5.51×10-6N-1、6.45×10-6N-1和4.05×10-5N-1。

The experiment was carried out with one-year-old seedling of three elm trees. Under artifical arid condition the changes of relative water content (RWC), wilting coefficient (WC), chlorophyll content (Chl), activity of catalase (CAT), proline(Pro), solvable sugar(SS) and MDA in their leaves were determined. Pro,SS and MDA might be taken as reference indexes of drought-resistanced appraisal for Ulmus thomasii Sarg., U. crassifolia and U. pumila through principal component analysis.