中文摘要：

以杉木成熟材晚材为研究对象，采用化学成分选择性脱除方法依次脱除木质素和半纤维素。利用纳米压痕技术，在纳米尺度上，探讨半纤维素和木质素对木材细胞壁压入力学性能的影响。结果表明：木质素对细胞壁的弹性模量影响显著，脱除木质素后细胞壁弹性模量损失了6．53％。半纤维素是一种界面高分子，在细胞壁中作为连接纤维素和木质素的界面偶联剂，对细胞壁的纵向弹性模量影响极显著，脱除半纤维素后细胞壁弹性模量损失约为9．16％。木质素和半纤维素对细胞壁的硬度影响均显著。木质素脱除后，细胞壁硬度降低了16．98％。半纤维素脱除处理与脱木质素处理相比，硬度仅下降了0．87％。

英文摘要：

In this study, we used targeted modification method to extract lignin and hemicellulose from mature latewood of Chinese fir （Cunninghamia lanceolata （Lamb.） Hook ） successively. We applied nanoindcntation technology to study the effects of hemicellulose and lignin on nano-mechanical properties of wood cell wall at nano-scale. Results showed that lignin influenced the modulus of elasticity （MOE） significantly （at 0.05 level）. The loss of elastic modulus was 6.53% after de-lignifing treatment. Hemicelluloses, which act as an interfacial coupling agent between the highly ordered cellulose of the microfibrils and lignin, affected MOE of cell wall significantly （ at 0.01 level）. The loss of elastic modulus was about 9.16% after being treated with hemicellulose extraction. Hemicellulose and lignin affected the hardness of cell wall significantly （ at 0.05 level）, which decreased with the degradation of hemicellulose or lignin. After de-lignifing treatment, the hardness of cell wall decreased by 16.98%, while it only decreased by 0. 87% after hemicellulose-extracting treatment.