中文摘要：

竹材光变色和光化降解过程比较复杂。该文以我国资源丰富的毛竹为研究对象，利用氙光衰减仪对竹材进行表面劣化处理，采用傅里叶变换红外光谱（FTIR）和X射线光电子能谱分析（XPS）对竹材表面化学组成和结构的变化进行表征。XPS测试结果表明，竹材表面光劣化处理后其O元素含量及氧碳比（O/C）明显增加;从C原子结合形式来看，C1（C—C）含量减少，C2（C—O）含量增加，C3（CO）和C4（OCO）含量增加明显，C的氧化态显著升高。FTIR分析表明，光劣化处理使得与木质素有关的吸收峰（如1 604，1 512及1 462 cm-1）强度明显降低，木质素发生降解，同时1 735 cm-1处非共轭羰基吸收峰强度明显增强，表明有新的羰基类物质生成，竹材表面发生光氧化反应。竹材表面的多糖物质（纤维素和半纤维素）受光劣化影响较小，其表面多糖相对含量在劣化处理后明显提高。

英文摘要：

The photodegradation process of bamboo involves very complex chemical reactions. In the present study, surface deterioration of Moso bamboo （Phyllostachys pubescens Mazel） was carried out by a xenon fade meter which can simulate sunlight irradiation, and Fourier transform infrared spectroscopy （FTIR） and X-ray photoelectron spectroscopic （XPS） techniques were used to characterize the resulting changes in the chemical structure and composition of bamboo surface. XPS results showed that light irradiation resulted in significant increases in oxygen （O） content and O/C ratio. Besides, changes were also identified from the detailed C（1s） spectra, with a remarkable decrease in C1 component （C-C） and simultaneous increases in the components of C2（C--O）, C3（C=O） and CA（O--C=O）, suggesting that the carbon atoms at bamboo surface were highly oxidized. FTIR results showed that lignin was susceptible to light irradiation and was significant degraded after treatment, as indicated by remarkable decreases in the intensity of lignin associated bands （e. g. 1 604, 1 512 and 1 462 cm^-1 ）. This was accompanied by the formation of new carbonyl compounds as shown by an obvious increase in the intensity of non-conjugated carbonyl group at 1 735 cm^-1 , which further indicated the photo-oxidation of bamboo surface. The polysaccharides （cellulose and hemicellulose） components, however, were less influenced by light irradiation, and their re, lative content at bamboo surface increased significantly due to lignin degradation.