论文部分内容阅读
应用光学显微镜、扫描电子显微镜和色度计 ,研究了毛竹竹材表面经紫外线照射后细胞壁的破损程度 ,具木质素组织分解深度以及颜色变化等规律。结果表明 :经紫外线照射后 ,在竹材横切面上 ,纤维细胞壁的分解始于次生壁各层连接处 ,接着是细胞角隅处和复合中层 ,最后纤维细胞壁全部被分解消失。薄壁组织细胞壁的复合中层先被分解 ,随后细胞壁分解变薄、坍塌和消失。竹秆壁表面的分解 ,最初从表皮细胞的短细胞开始 ,然后扩展到其它表皮细胞。根据木质素的显色反应显示 ,紫外线照射竹材样品 4 0d时 ,薄壁组织比纤维组织分解得更深 ,其中前者为 5 90 μm ,而后者只有 1 4 6μm。另外 ,经紫外线照射后的竹材样品 ,其横切面上的颜色和亮度变化最大 ,径向切面次之 ,竹秆壁表面变化最小。本文还讨论了经紫外线照射后 ,竹材中具薄壁组织比纤维组织分解更深的原因 ,以及样品 3个面上颜色和亮度变化的机制
Using optical microscope, scanning electron microscope and colorimeter, the damage of the cell wall, the depth of lignin decomposition and the change of color of bamboo surface after UV irradiation were studied. The results showed that after the UV irradiation, the fiber cell wall began to break down at the junction of the secondary wall, the cell corner and the compound middle layer on the cross section of the bamboo, and the final fiber cell wall was decomposed and disappeared. The parenchyma of the parenchyma cell wall is first decomposed, and then the cell wall decomposes, thinning, collapsing and disappearing. The decomposition of the surface of the bamboo stalk wall initially begins with short cells of the epidermal cells and then extends to other epidermal cells. According to the color reaction of lignin, the parenchyma tissue decomposed more deeply than the fibrous tissue on the 40th day after UV irradiation, of which the former was 5 90 μm, while the latter was only 146 μm. In addition, the UV-irradiated bamboo samples showed the largest change in color and brightness on the cross section, followed by the radial cut and the smallest change on the surface of the bamboo wall. The paper also discusses the reason why the parenchyma in bamboo material decomposes more deeply than the fibrous tissue after UV irradiation, and the mechanism of color and brightness changes on the three surfaces of the sample