DENSITY OF WOOD SUBSTANCE AND POROSITY OF WOOD
DENSITY OF WOOD SUBSTANCE AND POROSITY OF WOOD
复制标题
木材密度和木材孔隙率
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
Frederick Duniap
中科院分区：
文献类型：
--
作者：
Frederick Duniap
本文所提出的研究结果是为了确定构成木材的细胞壁的木质纤维素的密度，作为计算木材孔隙率的基础。一块木头的密度不同于构成它的木质纤维素的密度，因为木头是多孔结构，不是均匀的固体。木质纤维素的密度大于单位，在水中会下沉；木块会浮起来，尤其是在干燥的时候，因为它们所含的空气使它们浮起来。因此，一块木头的体积由两部分组成，一个是木质纤维素的框架，另一个是包含在前者中的大量小空腔。这些空腔可被各种流体、包覆材料和固体物质所占据。这些空腔的体积总和与整个块的体积之比是木材孔隙率的度量。整个块体的体积很容易确定（例如，通过浸没），因此孔隙度的确定就可以归结为空腔体积的确定。用已知密度的流体填充空腔，可以直接测量空腔的体积；实际上，这样的测量从来没有完全成功过。通过测定木材物质的密度，然后计算其在一块木材中的体积，也可以间接得到相同的结果；砌块的总体积和固体物质的体积之差就是空腔的体积。技术问题的关系
The investigation the results of which are presented in this paper was made to determine the density of the lignocellulose which makes up the walls of the cells of which wood is composed as a basis for calculating the porosity of wood. The density of a block of wood differs from that of the lignocellulose of which it is built up, because wood is a porous structure and is not a homogeneous solid. Lignocellulose has a density greater than unity and sinks in water; blocks of wood float, especially when dry, because the air they contain buoys them up. The volume of a block of wood is thus made up of two parts, a framework of lignocellulose and a large number of small cavities inclosed in the former. The cavities may be occupied by a variety of fluids, incrusting materials, and solid substances. The ratio of the sum of the volumes of these cavities to the volume of the entire block is the measure of the porosity of the wood. The volume of the entire block is readily ascertained (by submersion, for example), so that the determination of porosity resolves itself into a determination of the volume of the cavities. The volume of the cavities may be measured directly by filling them with a fluid of known density; actually such measurements have never met with entire success. The same result can also be reached indirectly by determining the density of the wood substance and then calculating its volume in a block of wood; the difference between the gross volume of the block and the volume of the solid substance is the volume of the cavities. RELATION TO TECHNICAL PROBLEMS