摘要:By means of X-ray diffraction and adsorptional test, The degree of relative crystallinity (Cr1%) of the wood cellulose in the stem of Larix gmelinii Rupr. was determined. The results of the experiments are given as follows:1. There are differences of the Cr1% in different parts in larch cross section. The immature wood is the lowest, the heart wood is the medium and the sapwood is the highest. After steaming high-temperature drying, the Cr1% of the three parts have been increased respectively. The Cr1% of the immature wood is from 54.3% to 55.1%, the heart wood is from 57.5% to 59.5% and the sapwood is from 59.6% to 60.1%.2. The adsorption of wood is a very important physical property and the effective factors are too many. So when the adsorption of wood is studied, we must consider the various factors, such as the chemical components and anatomical structure of wood.
摘要:This paper deals with the hybrid of Populus pseudo-simonii Kitag. x P. nigra L. in comparison with its parents of P.pseudo-simonii Kitag. The results show that hybrid grows faster than its parents and other features are not much difference, for example, fiber characteritics, vessel element characteristics, wood density and so on. These two poplar species can be used for paper making in juvenile trees. The increase of the width of ring is due to the increase of the number of cells.
摘要:The results on testing the decay resistance of Pinus Yunnanensis heartwood rotted in different levels with mediums of malt-ager, sand, soil and wood decay fungi (Coriolus Versicolor and Lenzites trabea) as well as the cells structural change of wood punky were reported. The results showed that the decay resistance of rotten timbers increased with the decrease of decay degrees. The observation of scanning electron microscopy indicated that the more hyphae penetrate holes in the cell walls, the higher decay levels of timber.