【作者】 曲志华；

【导师】 王立海；

【作者基本信息】 东北林业大学 ， 森林工程， 2011， 博士

【摘要】 木材腐朽造成巨大浪费,特别是真菌腐朽对木材破坏最为严重。据统计,我国每年由于真菌腐朽而损失的木材高达700万m3,所以对木材初期腐朽的研究具有重要意义。近红外光谱分析技术作为一种快速、低耗的无损检测技术,在农业、医药、化工领域已得到了广泛应用。在林业方面,木材作为一种高分子有机化合物,在近红外谱区有很强的吸收。随着化学计量学的不断发展,近红外光谱技术可以方便、快速、无损地对木材性质进行分析和预测。本文运用白腐菌—云芝和褐腐菌—密粘褶菌对针叶科树种冷杉及阔叶科树种胡桃楸进行接种并对腐朽进行了跟踪研究,分析了在不同的腐朽阶段、不同菌种对木材的结晶度、木质素及综纤维素的降解能力；运用近红外光谱技术结合偏最小二乘法对2种木材的结晶度进行预测；运用近红外光谱技术结合主成分分析法及偏最小二乘法2种化学计量学方法分别对冷杉及胡桃楸的木质素、综纤维素含量进行预测；最后,结合木材的结晶度运用近红外光谱技术及PCA-BP人工神经网络对冷杉及胡桃楸进行腐朽分级的初步研究。研究结果表明：(1)两种菌种对冷杉及胡桃楸木材的结晶度及综纤维素均有较强的降解能力,0～120d内冷杉结晶度白腐损失率达26.7%,褐腐损失率达21.9%,对于胡桃楸结晶度白腐损失率达22.5%,褐腐损失率达20.9%,冷杉综纤维素含量白腐损失率达49.89%,胡桃楸综纤维素含量白腐损失率达45.65%,冷杉及胡桃楸的综纤维素含量褐腐损失率达41.67%及43.53%；白腐菌—云芝对冷杉及胡桃楸木材的木质素均有较强的降解能力,0～120d内冷杉木质素损失率达55.3%,胡桃楸木质素损失率达58.1%,而褐腐菌—密粘褶菌基本不降解冷杉及胡桃楸木材的木质素。(2)对试样的近红外光谱进行平滑、基线校准、导数及多元散射校正不同预处理,通过对比发现光谱经一阶导数处理所建模型最优。(3)运用主成分分析法及偏最小二乘法2种方法所建模型均能对样品的木质素、综纤维素含量进行有效预测,近红外光谱结合偏最小二乘法所得的结果要优于近红外光谱结合主成分分析法,且预测效果理想。(4)结合木材的结晶度运用近红外光谱技术及PCA-BP人工神经网络可以对冷杉及胡桃楸进行腐朽分级,对冷杉腐朽分级正确率达86.7%,对胡桃楸腐朽分级正确率达80%。更多还原

【Abstract】 Wood decay caused great waste, especially rot decay, according to statistics, every year, about7million cubic metres wood has been lost due to rot decay in China, so research on wood rot decay was important. Near Infrared Spectroscopy testing as time-saving and low power consumption testing method has been widely applied in agriculture, medical section and chemical industry. Wood is Macromolecular organic compounds. It can be absorbed by near Infrared. The developing of chemometrics make the near infrared spectroscopy can be employed to detect the quality of wood.Researching the decayed process of Manchurian Walnut and Fir which vaccinated by white rot and brown rot, analyzing the degradation ability to wood crystallinity^lignin and holocellulose of Manchurian Walnut and Fir in different decayed stages and different strains;It builds the Manchurian Walnut and Fir crystallinity prediction models by using the principle partial least square method; It builds the lignin and holocellulose prediction models of Manchurian Walnut and Fir by using the principal component analysis method and principle partial least square method.At last, based on wood crystallinity Fir and Manchurian Walnut were predicted and graded accurately with NIR combined with PCA-BP neural network.The results showed that:(1)The two kinds of strains both have the strong degradation ability to Manchurian Walnut and Fir.To Fir, from0day to120days, the loss rate of wood crystallinity vaccinated by white rot values of26.7%, and21.9%to the brown rot; as to Manchurian Walnut,22.5%for the Fir and20.9%for the Manchurian Walnut. Meanwhile, the loss rate of Fir holocellulose content vaccinated by white rot is49.89%, and41.67%to the brown rot, in the same condition,45.65%and43.53%to Manchurian Walnut. However, to lignin, the degradation ability of these two strains is very different from crystallinity and holocellulose, to Fir, the loss rate of lignin vaccinated by white rot reaches to55.3%, and58.1%to Manchurian Walnut. The Contrast, brown rot has little degradation ability to lignin of Manchurian Walnut and Fir.(2) After the comprehensive analysis and assessment of Manchurian Walnut and Fir crystallinity prediction models built based on the original spectra and the spectral data preprocessed by smoothing method, baseline calibrated method, the firat derivative method and multivariate scattering correction. The results showd that the firat derivative method shows a better result than that by other preprocessing methods.(3) The results show that the principal component analysis method and principle partial least square method can get good prediction results for lignin and holocellulose. Howerer, the principle partial least square method can get a better prediction result than the principal component analysis method.(4) Based on wood crystallinity Fir and Manchurian Walnut was predicted and graded accurately with NIR combined with PCA-BP neural network. For Fir,the grade right rate was86.7%, for Manchurian Walnut, the grade right rate was80%.更多还原