Digital technology is being increasingly designed and employed to support the preservation and restoration of ancient murals. The contributions of digital technologies to this study were planned from the very beginning, as the complexity of this restoration necessitated the design of innovative procedures to manage the restoration and reconstruction processes and to record the details and deformation of the mural. This paper takes the digital restoration of the "maid holding a fan" mural in the Tang Zhaoling Duan Jianbi tomb as an example. In view of the large number and dislocation of mural fragments, the application of digital restoration technology and its achievements in the restoration of this ancient mural are preliminarily explored in combination with high-precision digital information collection and recording. Technical suggestions and details regarding the digital restoration of the mural are put forward to serve as guidance for the preservation and restoration of ancient murals.

Curling disease in long historical photos significantly affects the presentation of cultural heritage information. However, people lack attention to the formation process and microstructural changes of photo curling. In this article, a long historical photo (1912–1949 AD) collected by the Second Historical Archives of China was taken as the research object, and the formation process and cause of the curling were further explored. Firstly, Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray energy disperse spectrometer (EDS), and other instruments were used to analyze the material composition of the long historical photo. It was found that the photographic paper was made of gelatin, barium sulfate, and plant fiber layers. Then, the effects of hygrothermal environments on curling and contraction in the gelatin layer and simulated photographic paper were explored. Meanwhile, the formation process and main influence factors of the curling were preliminarily revealed. The morphological analysis by SEM was carried out to identify the inner correlation between the microstructure and curling of photos. Finally, the possible formation cause of photo curling was analyzed. This study provides a scientific basis and experimental data for the preservation and restoration of long historical photos based on gelatin.

Flood control initiated Chinese civilization. Chinese civilization has a long history, and Chinese ancestors invented “aquatic engineering technology” for flood control and water management, including the Fascine body, as early as two thousand years ago. The Fascine body is a structure used to protect the bank and prevent breaching of an ancient Chinese flood control project. Excavation of the Shahe ancient bridge ruins in Xi’an City, Shaanxi Province, China led to discovery of a Fascine body structure. Through ¹⁴C dating, fibre, slice observations, infrared spectroscopy, X-ray diffraction, thermogravimetric analyses and SEM energy spectrum analyses of the fascine material, microbes in the structure and the surrounding soil were identified, the dominant microbial community was analyzed, and microbial diseases were controlled in a targeted manner. Research on the fascine bank ruins identified the width and length boundaries of the Shahe ancient bridge, determined the exact age of the Shahe ancient bridge, provided important materials for research on ancient bridges, river embankments and other ruins, and provided important clues for the traffic and layout around Chang’an during the Qin and Han Dynasties of Chinese history.

Quest for bio-based halogen-free green flame retardant has attracted many concerns in recent years. Herein a reactive functional flame retardant containing phosphorus VDP is synthesized from vanillin, 9,10-dihydro-9-oxa-10-phosphophene-10-oxide (DOPO) and phenol via a facile way. VDP is characterized with 1H NMR, 31P NMR, FTIR and Time of Flight Mass Spectrometry, and used as a new reactive flame retardant for bisphenol epoxy thermosets. Thermogravimetry analysis shows that when the VDP loading is only 0.5P% (based on phosphorus content), the residue increases from 14.2% to 21.1% at 750°C in N2 compare with neat DGEBA. Correspondingly, the limit oxygen index increased to 29.6%, and flame retardancy reaches UL-94 V0 grade. Micro combustion calorimetry (MCC) and cone calorimetry analyses demonstrate that VDP can significantly lower flammability of the epoxy thermoset. With only 0.5P% of VDP, the heat release rate, total heat release rate and smoke production are reduced markedly. At the same time, the mechanical properties of the modified epoxy thermosets are also improved. The impact strength increases by 34% and the flexural strength increased by 23%, with 1.5P% of VDP. In short, VDP not only improves the flame retardancy, but also improves the mechanical properties of the epoxy thermosets.

The development of efficient green flame retardants is an important way to realize more sustainable epoxy thermosets and downstream materials. In this work, a monoepoxide is synthesized through O-glycidylation of eugenol, and then reacted with DOPO (9,10-dihydro-9-oxa-10-phosphophenanthrene-10-oxide) to obtain a new bio-based flame retardant, DOPO-GE. DOPO-GE is blended with a bisphenol A epoxy prepolymer exhibiting good compatibility and DDS (4,4′-diaminodiphenylsulfone) is used as the curing agent to afford epoxy thermosets. Although DOPO-GE leads to the reduced glass transition temperature of the thermosets, the storage modulus increases considerably. The DOPO-GE-modified thermosets exhibit the high thermal stability with the onset thermal decomposition temperature in nitrogen and air exceeding 300°C. When the phosphorus content in the thermoset is 1.0%, the residual yield of the thermosets at 750°C in nitrogen increases from 13.9% to 30.6%, due to the increased charring ability. More interestingly, when the phosphorus content is only 0.5%, the limiting oxygen index is as high as 30.3% with UL94 V0 achieved. Cone calorimeter results reveals the signifi- cantly decreased heat release rate, total heat release, mass loss and total smoke production. Furthermore, DOPO-GE can notably improve the flexural strength, flexural modulus and fracture toughness, whereas the shear and impact strength are reduced to varied extents. In short, DOPO-GE can be obtained via a facile way, and shows the good flame-retardant effect on the epoxy thermosets with an application potential.

Jiatang scroll paintings listed in the Chinese intangible cultural heritage list are an important form of family trees. In this paper, a Jiatang scroll painting drawn in the seventh year of Guangxu (AD 1881) was chosen as a prototype to analyze its components. Samples were taken from different parts of the Jiatang scroll painting to analyze the composition of fibers, pigments, and adhesives. Herein, fiber analyzer, Fourier transform infrared spectroscopy (FTIR), and Herzberg stain were conducted to identify the type of fiber used. Microstructural and microchemical analyses by means of SEM-EDX and Raman spectroscopy were performed to characterize the pigments present in the painting, while the nature of the adhesive was examined using pyrolysis gas chromatography–mass spectrometry (Py-GC/MS). The results show that the painting fiber is from cotton, while the red, black, and green pigments were identified as cinnabar, carbon black, and emerald green, respectively. Finally, the adhesive is a mixture of animal glue, benzoin gum, and starch. The research results provide a basis for the protection and restoration of this precious cultural heritage in the future.