Wood is usually stable under relatively dry conditions but may still undergo slow deterioration. The type of deterioration and how these processes affect the wood are important questions that need consideration if old wooden structures are to be studied and properly preserved. The aim of this paper is to establish the main structural and morphological differences between new and naturally aged European spruce (~ 150–200 years) and silver fir wood (~ 150 years). Naturally aged European spruce (a) was sourced from an outdoor part of a building constructed in the seventeenth century and naturally aged European spruce (b) were obtained from a furniture item located in a historical building from the eighteenth century. The principal age-induced changes in fir are the degradation of C–O and C=O groups in hemicellulose, according to the FTIR analysis. Degradation of cellulose and hemicelluloses was observed for spruce, with a greater effect seen in the indoor aged sample. X-ray photoelectron spectroscopy (XPS) showed that after aging C–C/C–H peaks were smaller in the spruce and fir samples, while C–O and O–C–O peaks were larger. The crystallinity index (CrI) obtained by X-ray diffraction showed that due to weathering the CrI of naturally aged spruce (a) increased compared to the new wood. The CrI of the aged spruce (b) and aged fir was lower than in the new woods. The ratios for the spruce sample, which aged indoors, were higher than those for the one aged outdoors. According to the observations made in this study, hemicellulose and cellulose are easily degraded under environmental conditions.

中文翻译：

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深入研究自然老化对欧洲云杉（Pice abies）和银冷杉（Abies alba）木材化学结构的改性作用

木材通常在相对干燥的条件下稳定，但仍可能缓慢变质。如果要研究并妥善保存旧木结构，则退化的类型以及这些过程如何影响木材是重要的问题。本文的目的是建立新的和自然老化的欧洲云杉（约150-200年）和银杉木（约150年）之间的主要结构和形态差异。自然老化的欧洲云杉（a）来自17世纪建造的建筑物的室外部分，自然老化的欧洲云杉（b）来自位于18世纪历史建筑中的家具。根据FTIR分析，冷杉引起的年龄变化主要是半纤维素中C–O和C = O组的降解。观察到云杉降解了纤维素和半纤维素，在室内老化样品中观察到了更大的影响。X射线光电子能谱（XPS）显示，老化后的云杉和冷杉样品中C–C / C–H峰较小，而C–O和O–C–O峰较大。通过X射线衍射获得的结晶度指数（CrI）表明，由于风化，自然老化的云杉（a）的CrI与新木材相比有所增加。老化的云杉（b）和老化的杉木的CrI低于新木材。在室内老化的云杉样品的比率高于在室外老化的云杉样品的比率。根据这项研究的观察结果，半纤维素和纤维素在环境条件下很容易降解。在室内老化样品中看到的效果更大。X射线光电子能谱（XPS）显示，老化后的云杉和冷杉样品中C–C / C–H峰较小，而C–O和O–C–O峰较大。通过X射线衍射获得的结晶度指数（CrI）表明，由于风化，自然老化的云杉（a）的CrI与新木材相比有所增加。老化的云杉（b）和老化的杉木的CrI低于新木材。在室内老化的云杉样品的比率高于在室外老化的云杉样品的比率。根据这项研究的观察结果，半纤维素和纤维素在环境条件下很容易降解。在室内老化样品中看到的效果更大。X射线光电子能谱（XPS）显示，老化后的云杉和冷杉样品中C–C / C–H峰较小，而C–O和O–C–O峰较大。通过X射线衍射获得的结晶度指数（CrI）表明，由于风化，自然老化的云杉（a）的CrI与新木材相比有所增加。老化的云杉（b）和老化的杉木的CrI低于新木材。在室内老化的云杉样品的比率高于在室外老化的云杉样品的比率。根据这项研究的观察结果，半纤维素和纤维素在环境条件下很容易降解。而C–O和O–C–O峰较大。通过X射线衍射获得的结晶度指数（CrI）表明，由于风化，自然老化的云杉（a）的CrI与新木材相比有所增加。老化的云杉（b）和老化的杉木的CrI低于新木材。在室内老化的云杉样品的比率高于在室外老化的云杉样品的比率。根据这项研究的观察结果，半纤维素和纤维素在环境条件下很容易降解。而C–O和O–C–O峰较大。通过X射线衍射获得的结晶度指数（CrI）表明，由于风化，自然老化的云杉（a）的CrI与新木材相比有所增加。老化的云杉（b）和老化的杉木的CrI低于新木材。在室内老化的云杉样品的比率高于在室外老化的云杉样品的比率。根据这项研究的观察结果，半纤维素和纤维素在环境条件下很容易降解。高于户外活动者的年龄。根据这项研究的观察结果，半纤维素和纤维素在环境条件下很容易降解。高于户外活动者的年龄。根据这项研究的观察结果，半纤维素和纤维素在环境条件下很容易降解。