Analysis of periodical structures of woods

点击翻译按钮获取中文摘要

In the new idea that "Woods is the assembly of various periodical structures from macro- to micro-levels and the wood property is affected by the periodicity", following subjects; environmental factors for wood production and the occurrence of periodicities; anisotropical periodicities on the arrangement of cells and tissues; the periodical distribution of main cell wall componemts; dielectric, acoustic and visual characteristics affecting wood properties, were examined and attmpted to be related with one another. The method for the analysis of periodicities was mainly performed by the fourier transformation . As the results, anisotropic periodicities of trancheid and vassel distributions on the transverese section, of ray distribution on the tangential section and the three-dimensional shapes and arrangements of fibers could be caught and were related to some wood properties. Cellulose microfibrils are suggested to be orientating periodically on their cross direction and lignin may be changed in its chemical structure during the depositing season in a year.