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According to the environmental conditions of acid rain and fog in Dazu， Chongqing， the corrosion resistance of traditional gold glue paint used for gilding of cultural relics to wet polluted atmosphere was studied by a variety of simulated accelerated aging tests and combining with analytical methods such as infrared spectroscopy， contact angle， and morphology observation.Results showed that atmospheric acid rain pollution accelerated the impact of the alternating wet and dry environment of water on gold glue paint.Additionally， light， humidity and the alternating wet and dry environment of polluted atmosphere had varying degrees of influence on gold glue paint.Among them， the alternating dry and wet environment of polluted atmosphere possessed the most serious damage to the aging resistance of gold glue paint， which eventually led to the corrosion damage of gold gule paint materials.

Palm leaf manuscripts (PLMs), venerable historical artefacts containing Buddhist scriptures, history, mathematics and literature, which are carried by palm leaves (Corypha umbraculifera) and are highly susceptible to microbial degradation during prolonged storage. This degradation results in significant alterations to both the appearance and material properties of PLMs, but the precise mechanism underlying this deterioration remains a mystery. To this end, the present study focused on ancient PLMs from Xishuangbanna Dai Autonomous Prefecture in Yunnan Province, China. The objective of present study was to isolate, culture and identify the microorganisms typically found in these manuscripts and to use them to biodegrade the carriers of PLMs. Detailed observations of the biodegradation behavior of these microorganisms on the carriers of PLMs were carried out, together with characterizations of the hierarchical structure and mechanical properties of the leaf fiber cell walls. This comprehensive analysis provided insights into the deterioration mechanisms of the carriers of PLMs. The study revealed the presence of the common fungus Aspergillus niger on ancient PLMs. Aspergillus niger can secrete cellulase, lipase, and acidic substances after colonizing on the carriers of PLMs. These substances sequentially damage the carrier's epidermal cells, mesophyll cells, and leaf fibers, leading to the separation of different tissue structures. At the molecular level, the lipids on the surface of the leaves were degraded initially, and sequential depolymerization of hemicellulose, amorphous cellulose, and crystalline cellulose occurred. Additionally, this study firstly applied nanoindentation technology in the research of PLMs. The mechanical properties of the cell walls underwent notable alterations due to the modifications in chemical and crystalline structure of the carriers of PLMs upon the biodegradation of Aspergillus niger. Specifically, the hardness and elastic modulus of leaf fiber cell walls showed an initial increasing and then decreasing trend, consistent with the trend of cellulose crystallinity, which also provided a new reference for assessing the degree of deterioration of PLMs. [ABSTRACT FROM AUTHOR]

Waterlogged archaeological wood samples may degrade during long-term immersion in microbial-activity environments, which causes its biodegradation. Simultaneous dynamic vapor sorption (SDVS) and two-dimensional correlation infrared (2D COS-IR) spectroscopy reveal the degradation inhomogeneity of waterlogged fir wood from the Shengbeiyu shipwreck. The waterlogged and reference wood exhibit type II sorption isotherms. The equilibrium moisture contents of waterlogged archaeological fir wood from a decay region (WFD) were 22.5% higher than those of waterlogged archaeological fir wood from a sound region (WFS). WFD exhibits a higher measurable sorption hysteresis than WFS, implying greater variation in the surface moisture content in the WFD region compared to the WFS region, which may compromise the dimensional stability of the shipwreck. 2D COS-IR spectra confirmed the inhomogeneous degradation of the waterlogged wood via numerous mechanisms. The efficacy of SDVS and 2D COS-IR spectroscopy in the evaluation of the degradation state of waterlogged wood was demonstrated. This study verifies the existence of hygroscopic and chemical differences between visually similar samples from the same shipwreck. [ABSTRACT FROM AUTHOR]