延安时期红色文献的红外光谱无损检测研究

延安是中国共产党领导革命的中心和战略总后方，是革命的红色摇篮。延安时期出版了大量具有历史、文化以及教育意义的红色文献，这些红色文献记载了中国共产党波澜壮阔的发展历程，也反映了延安时期不断发展的科技生产水平与独特的制浆造纸工艺，具有重要的研究价值。然而，延安时期出版的红色文献虽距今不到百年时间，但其保存现状不容乐观，普遍存在纸张老化、焦脆易碎等问题，大量文献急需科学检测与修复保护，以延长其保存寿命。目前，针对延安时期红色文献的检测研究仍存在较大空白。考虑到红色文献的珍贵性与特殊性，应当尽可能选择无损检测方法对其分析检测。基于衰减全反射-傅里叶变换红外光谱法（ATR-FTIR），以木素1 510 cm-1处特征峰与纤维素1 030 cm-1处特征峰的强度作为定量依据，建立了造纸原料与红色文献纸张中木素相对含量的无损检测方法。通过检测不同碱强度与碱浓度处理后的构皮、苦竹与杨木的木素含量，考察了制浆过程中碱处理条件对造纸原料脱木素程度的影响，同时体现了红外光谱法测定木素相对含量的普适性。以复旦大学图书馆藏的76册延安时期红色文献为研究对象，分析了红色文献的纸张木素含量与纸张pH值以及纸张氧化度的相互关系。结果表明，木素相对含量高于25%的红色文献，其纸张pH集中在3～4之间且纸张氧化度较高，文献整体保存状况堪忧；而木素相对含量低于25%的红色文献，其纸张氧化度与酸度较低，文献整体保存情况较好。以上结果验证了红外光谱无损检测法用于延安时期红色文献木素含量分析的可行性，并结合纸张氧化度与酸度数据提出了纸张木素含量的合适范围，为制浆造纸中植物原料的脱木素过程提供参考。拓展了红外光谱法在红色文献无损检测中的应用范围，以期为延安时期红色文献的修复与保护研究提供科学依据。

Non-Destructive Analysis of Yan’an Red Literature by FTIR Spectroscopy

Yan’an was the revolution center and strategic backside of the Communist Party of China and the cradle of revolution. Large numbers of red kinds of literature with historical, cultural, and educational significance were published in the Yan’an period, which recorded the grand development of the Communist Party of China and reflected the continuous improvement of scientific and technological productive force as well as the unique pulping and paper making process in that period. Thus, the research value of Yan’an red kinds of literature is of great importance. However, although these red kinds of literature have a history of fewer than 100 years, their preservation situations are not optimistic, and problems such as aging and embrittling of paper are widespread. These books are in urgent demand of scientific detection and preservation to prolong their live performance. Research on the detecting and analyzing of Yan’an red literature is still blank. Non-destructive testing methods should have opted as far as possible. Based on Attenuated Total Reflection-Fourier Transform Infrared Spectroscopy (ATR-FTIR), the intensity of the characteristic peak at 1 510 cm-1 of lignin and 1 030 cm-1 of cellulose was used as the quantitative foundation to establish the non-destructive testing method of the relative lignin content in paper raw materials and red literature paper. The effect of alkali strength and concentration on the degree of delignification during the pulping process was investigated by examining the lignin content of paper mulberry bark, bitter bamboo and poplar. The generality of FTIR method for determining the relative lignin content was also demonstrated. The relationship between the paper lignin content and the paper pH value or the paper oxidation degree was studied for Yan’an red kinds of literature collected in Fudan University Library. The results showed that red kinds of literature with relative lignin content higher than 25% had a higher paper oxidation degree and acidity(pH 3~4), and the overall preservation situation of this literature was worrisome. However, the red kinds of literature with relative lignin content lower than 25% had a lower paper oxidation degree and acidity, and their overall preservation situation was relatively good. The above results indicate the feasibility of the FTIR method for the determination of lignin content of Yan’an red kinds of literature, and propose a suitable range of paper lignin content in combination with paper oxidation degree and acidity, providing a reference for the delignification process of raw plants in pulping and paper making. This work expands the application of FTIR spectroscopy in the non-destructive analysis of red literature and provides a scientific basis for the research of preservation and conservation of red literature in the Yan’an period.