硬木中流体移动的双尺度多孔机理的依据(Ⅰ)用多色X光束测定榉木浸润中湿含量的演变

• 来源期刊: 中国化学工程学报（英文版）
• 学科: 工学
• 关键词: density heartwood moisture profile non-destructive measurement sapwood shrinkage wood
• 年，卷（期）: 2004,（6）
• 页码范围: 773-782
• 页数: 10页
• 分类号: TQ0
• 语种: 英文

摘要

An experimental device able to determine the moisture content of wood using X-ray attenuation is usedto study the imbibition of beech samples (Fagus silvatica). The apparatus includes an X-ray generator, a protectivetube, collimating plates and a 50 mm detector. Detected particles can be categorised by energy (accuracy of theorder of 20%) or by position (accuracy 100μm). The independent choice of both the energy spectrum (throughthe voltage) and the counting rate (through the current intensity) makes the installation very flexible. However,a rigorous treatment is necessary to deal with the attenuation of a polychromatic spectrum. The appropriatecalculations are presented and validated with homogeneous samples made of wood and water. In addition, someresults are presented with samples heterogeneous in density and moisture content. Finally, the experimental deviceis used to study the evolution of moisture content during saturation experiments, for which the moisture migrationis mainly due to capillary forces. The geometrical configuration was so arranged that the transfer can be studied intwo directions simultaneously.