Evaluation of wood variation based on the eigenvalue distribution of near infrared spectral matrix
Evaluation of wood variation based on the eigenvalue distribution of near infrared spectral matrix
复制标题
基于近红外光谱矩阵特征值分布的木材变异评价
DOI：
10.1177/0967033518812894
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发表时间：
2018
影响因子：
1.8
通讯作者：
Takaaki Fujimoto
中科院分区：
文献类型：
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作者：
Takaaki Fujimoto
提出了一种基于近红外光谱矩阵特征值分析的木材变异评价方法。将由方差-协方差矩阵计算得到的本征值集作为代表木材能量本征态的哈密顿量，从热力学和统计力学的角度讨论了木材的变异。为了确定这一想法的有效性，制备了两个样品组，一个具有高弹性模量（Efr），另一个具有低弹性模量（Efr），因为它们在细胞壁中显然具有不同的分子构型。与低Efr组相比，高Efr组的特征值分布较广。与高Efr组相比，低Efr组的每个能量本征态对应的概率是平坦分布的。这些结果表明，低Efr木材比高Efr木材具有更无序的结构。亥姆霍兹自由能在高Efr组中较高;相反，熵在低Efr组中较高。本研究结果与前人关于木材力学性能与微观结构关系的认识相一致。因此，从近红外光谱矩阵获得的特征值提供了有用的信息，以评估木材的变化和稳定性。
A method to evaluate the wood variation based on the eigenvalue analysis for the near infrared spectral matrix is presented. The set of eigenvalues calculated from the variance-covariance matrix is treated as the Hamiltonian, which represents the energy eigenstate of the wood, and the wood variation is discussed from the viewpoints of thermodynamics and statistical mechanics. To determine the validity of this idea, two sample groups, one having a high and the other having a low modulus of elasticity (Efr), are prepared, because they obviously have different molecular configurations in the cell wall. The eigenvalues of the high Efr group are widely distributed compared with those of the low Efr group. The probability corresponding to each energy eigenstate of the low Efr group is flatly distributed compared with that of the high Efr group. These results indicate that the low Efr wood has a more disordered structure than the high Efr wood. The Helmholtz free energy is higher in the high Efr group; in contrast, the entropy is higher in the low Efr group. The results obtained in this study are consistent with the previous knowledge with regard to the relationship between the mechanical properties and the microscopic structure of wood. Hence, the eigenvalues obtained from the NIR spectral matrix provide useful information to assess the variation and stability of wood.