The change in the pore size of cell walls affects many physical properties of wood. In this paper, the dynamic changes in the pore size of wood cell walls during drying and moisture adsorption were studied at four relative humidities. The results showed that the average pore size of cell walls of Qingpi poplar (Populus- platyphylla var. glauca) was larger than that of pine wood (Pinus sylvestris var. mongolica Litv.) under the same experimental conditions, and the changes in pore size of Qingpi poplar cell walls were more sensitive to ambient humidity no matter whether during drying or moisture adsorption. Moreover, the average pore size of cell walls at saturated-water state is about 2.5 times of the average pore size of cell walls when woods reached the moisture absorption equilibrium from the oven-dry state. This article is useful for the wood manufacture industry and for wood modification. It is not only important for wood processing and utilization but also for the research on other porous materials.

中文翻译：

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干燥和吸湿过程中木材细胞壁平均孔径的时域核磁共振研究

细胞壁孔径的变化会影响木材的许多物理特性。本文研究了干燥和吸湿过程中木材细胞壁孔径在四种相对湿度下的动态变化。结果表明，在相同的实验条件下，青皮杨（Populus-platyphylla var. glauca）细胞壁的平均孔径大于松材（Pinus sylvestris var. mongolica Litv.），孔径的变化无论是在干燥过程中还是在吸湿过程中，青皮杨细胞壁对环境湿度都更加敏感。此外，饱和水状态下细胞壁的平均孔径约为木材从烘干状态达到吸湿平衡时细胞壁平均孔径的2.5倍。该物品可用于木材制造工业和木材改性。它不仅对木材加工利用具有重要意义，而且对其他多孔材料的研究也具有重要意义。