Wang Ruidong, Chen Shichao, Gao Yong
College of Desert Control Science and Engineering, Inner Mongolia Agricultural University, Hohhot, China.
Front Plant Sci. 2024 Sep 13;15:1451065. doi: 10.3389/fpls.2024.1451065. eCollection 2024.
sand barriers degrade under sunlight exposure, resulting in diminished protective performance and shortened service life in desertification control. To address the unresolved issue of photoinduced damage and degradation in sand barriers, we conducted simulations to assess the accelerated damage effect of ultraviolet (UV) rays during solar exposure of sand barriers. Our analysis focused on elucidating the mechanism of UV irradiation in sand barriers by examining the structural and material property changes that occur during the degradation process. The results indicated the following: (1) The discoloration of sand barriers resulting from UV irradiation was primarily ascribed to the modification in lignin content. (2) The morphology and protective performance of sand barriers underwent significant changes following exposure to UV irradiation. The 96-day and 144-day time points of UV exposure are crucial for evaluating the extent of UV degradation in sand barriers. After 192 days of UV irradiation, there was a decrease in mass loss percentage by 3.62%, modulus of elasticity by 8.63%, and modulus of rupture by 6.74%. (3) The lignin, hemicellulose, and cellulose content decreased by 23.12%, 14.30%, and 6.96%, respectively. The impact of UV irradiation on the polysaccharide (cellulose and hemicellulose) in sand barriers was relatively minimal. (4) The carbon binding form in sand barriers underwent a transformation, characterized by a significant decrease in C1 content and an increase in C2 and C3 content. This resulted in a gradual enhancement of the oxidation state and binding energy of carbon. Therefore, to prolong the utilization lifespan of sand barriers, it is essential to address the UV irradiation behavior from the perspective of inhibiting lignin reactions.
在阳光照射下，沙障会发生降解，导致其在荒漠化治理中的防护性能下降和使用寿命缩短。为了解决沙障光致损伤和降解这一尚未解决的问题，我们进行了模拟实验，以评估沙障在阳光照射期间紫外线（UV）的加速损伤效应。我们的分析重点是通过研究降解过程中发生的结构和材料性能变化来阐明紫外线在沙障中的照射机制。结果表明：（1）紫外线照射导致沙障变色主要归因于木质素含量的改变。（2）暴露于紫外线照射后，沙障的形态和防护性能发生了显著变化。紫外线暴露96天和144天的时间点对于评估沙障紫外线降解程度至关重要。紫外线照射192天后，质量损失百分比下降了3.62%，弹性模量下降了8.63%，断裂模量下降了6.74%。（3）木质素、半纤维素和纤维素含量分别下降了23.12%、14.30%和6.96%。紫外线照射对沙障中多糖（纤维素和半纤维素）的影响相对较小。（4）沙障中的碳结合形式发生了转变，其特征是C1含量显著下降，C2和C3含量增加。这导致碳的氧化态和结合能逐渐增强。因此，为了延长沙障的使用寿命，从抑制木质素反应的角度解决紫外线照射行为至关重要。
