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Abstract A comprehensive multi-analytical investigation was conducted on a piece of Longquan celadon excavated from the Shengbeiyu shipwreck site in the East China Sea. This study focused on a representative type of tubular bio-concretions attached to the submerged celadon, believed to have been formed through the construction activities of a marine tubeworm belonging to the benthic phylum of Polychaeta Annelids. The research examined the microstructure, composition and adhesion form of these tubular bio-concretions, aiming to elucidate their developmental and attachment patterns from a biomineralization and biofouling perspective. The tubular bio-concretions were found to have a bimineralic composition, with notably higher content of aragonite than calcite, and display diverse yet highly ordered microstructures. The presence of organic matter within the bio-concretions indicates an organic matrix-controlled crystallization model, commonly observed in the construction of benthic calcareous tubes. Microscopic analyses revealed the primary degradation microstructures and corresponding phases of the glaze to which calcareous tubes attached. These findings closely resembled the corrosion characteristics observed in submerged ceramic glaze without bio-concretion attachments, as documented in earlier studies. OM and SEM observations also indicated that the calcareous tubes intricately intermeshed with the cracked glaze layer of the celadon. Additionally, Raman spectroscopic analysis detected the presence of proteins at the interface, likely residual adhesives secreted by fouling organisms to cement themselves to the settlement substrata, suggesting the occurrence of organic-mediated bio-adhesion mechanisms. These results shed new light on the formation process of bio-concretions and their interaction with attached underwater ceramics. A simplified formation mechanism of this biologically-induced degradation has been discussed.

Organosilicon materials have shown potential as dehydration agents for waterlogged wooden artifacts. These materials can polymerize under normal conditions to form polymers with favorable mechanical strength, antibacterial properties, and aging resistance. However, the insolubility of most organosilicon hindered their penetration into waterlogged wood, which may lead to an unwanted cracking. This study aimed to evaluate the effectiveness of polydimethylsiloxane (PDMS) and hydroxy-terminated polydimethylsiloxane (PDMS-OH) with low viscosity and moderate reactivity for dehydrating waterlogged wooden artifacts from the Nanhai No.1 shipwreck. Four surfactants ((3–aminopropyl) triethoxysilane (APTES), alkyl polyoxyethylene ether (APEO), tri-methylstearylammonium chloride (STAC), and fatty alcohol polyoxyethylene ether (AEO)) and cosurfactant were employed to transform the two kinds of water-repellent silicone oils into eight groups of highly permeable oil-in-water (O/W) emulsions. Under the catalysis of a neutral catalyst, in situ polymerization occurred within the wood cells. Group P2-2 formulated with PDMS-OH and APEO showed the best efficiency in maintaining the dimensions of the wood during dehydration. The dehydrated wood exhibited a natural color and texture with a minimal volume shrinkage rate of 1.89%. The resulting polymer adhered uniformly to the cell walls, effectively reinforcing the wood cell structure. The weight percent gain of the wood was only 218%, and the pores of the cell lumen were well maintained for future retreatment. This method effectively controlled the sol–gel reaction process of the organosilicon and prevented damage to the wooden artifact during the dehydration process. Moreover, the dehydrated wood samples only experienced a low weight gain of 17% at 95% relative humidity (RH), indicating their great environmental stability.

Abstract The significance of waterlogged archaeological wood (WAW) lies in its profound informational value, encompassing historical, cultural, artistic, and scientific aspects of human civilization, and therefore need to be properly studied and preserved. In this study, the utilization of near-infrared (NIR) spectroscopy is employed as a predictive tool for assessing the hardness value of WAW. Given the submerged burial conditions, waterlogged wooden heritage frequently undergo substantial degradation in their physical and mechanical properties. The mechanical properties of waterlogged wooden heritage are essential for evaluating their state of preservation and devising appropriate conservation and restoration strategies. However, conventional methods for testing mechanical properties are limited by factors such as the availability of adequate sample size and quantity, adherence to the “principle of minimum intervention,” and cost considerations. NIR spectroscopy is a non-destructive, rapid, sensitive, and low-cost analytical technique with great potential for application in this area. In this study, two large and significant ancient Chinese shipwrecks were investigated. One hundred ninety-seven samples were collected and analyzed using NIR spectroscopy and a portable C-type shore hardness testing method. A partial least squares (PLS) regression model was developed to predict the hardness of the WAW. The model was optimized and validated using different preprocessing methods and spectral ranges. The results indicate that the best models were obtained with first derivatives + multiple scattering corrections (MSC) and first derivatives + standard normal variate (SNV) preprocessing in the 1000–2100 nm spectral range, both with an R 2 c of 0.97, a root mean squared error of correction (RMSEC) of 2.39 and 2.40, and a standard error of correction (SEC) of 2.40 and 2.41. Furthermore, they exhibited an R 2 v of 0.89 and 0.87, a root mean squared error of cross-validation (RMSECV) of 4.43 and 4.67, a standard error of cross-validation (SECV) of 4.45 and 4.68, and RPD values of 3.02 and 2.88, respectively. A coefficient of determination of the established prediction model (R 2 p) of 0.89 with a relative standard deviation for prediction (RSD) of 6.9%

Abstract Craquelure is the most common defect on ancient polychrome paintings, which may deteriorate further to paint loss. Previous image processing methods, which can accurately recognize paint loss, have limited precision and efficiency in segmenting craquelure. This paper proposes a semantic segmentation method, Res-UNet, for the recognition of craquelure and paint loss in the Palace Museum, Beijing. The residual structure of ResNet-50 enables the avoidance of network degradation, and image features can be fully extracted. Using the unique skip connection module of U-Net, features of different levels are fused to improve segmentation accuracy and provide smoother craquelure edges. Three loss functions are combined to accelerate stable convergence. The model was tested on a newly built dataset based on 600 images. Experimental results supported by statistical tests show that Res-UNet is a capable method of craquelure recognition, with an accuracy rate of 98.19%, and F1-score of 93.42%. Hence, the proposed hybrid approach is a promising tool to support the preservation and restoration of valuable traditional Chinese polychrome architectural paintings.

Tetraethoxysilane (TEOS) is the most commonly used silicon-based reinforcement agent for conserving art relics due to its cost-effectiveness and commercial maturity. However, the resulting silica gel phase is prone to developing cracks as the gel shrinks during the sol–gel process, potentially causing severe damage to the objects being treated. In this study, dodecyltrimethoxysilane (DTMS) was introduced into TEOS to minimize this shrinkage by adding elastic long chains to weaken the capillary forces. The gel formed from the DTMS/TEOS hybrid material was transparent and crack-free, featuring a dense microstructure without mesopores or micropores. It exhibited excellent thermal stability, with a glass transition temperature of up to 109.64 °C. Evaluation experiments were conducted on artificially aged, handmade bamboo paper. The TEOS-based hybrid material effectively combined with the paper fibers through the sol–gel process, polymerizing into a network structure that enveloped the paper surface or penetrated between the fibers. The surface of the treated paper displayed excellent hydrophobic properties, with no significant changes in appearance, color, or air permeability. The mechanical properties of the treated bamboo paper improved significantly, with longitudinal and transverse tensile strengths increasing by up to 36.63% and 44.25%, respectively. These research findings demonstrate the promising potential for the application of DTMS/TEOS hybrid materials in reinforcing paper relics.

Communication and sensing integrated networks (CSINs) refer to the ability of physical digital space perception and ubiquitous intelligent communication at the same time. These networks realize the perception and cooperative communication of multidimensional resources through the cooperative work of communication and sensing resources and have the ability of intelligent interaction and processing of new information flow. First, this study proposes the technical architecture of an enhanced CSIN (E-HFWN), studies its key technologies and performance indicators, and explains the air interface technology, including frame structure design, carrier aggregation, channel detection, physical skyline mapping, beamforming and management, resource allocation and scheduling. In the resource allocation scheme, an actor-critic reinforcement learning (RL) framework is used to divide the wireless resources. The goal is to maximize the amount of mutual information (MI) and minimize the end-to-end delay of the sensing terminal. Then, the performance of the E-HFWN is tested, including numerical simulation of wireless resource management, system peak rate, capacity, end-to-end delay and communication perception waveform sidelobe ratio. Finally, from the results of the E-HFWN index test, the E-HFWN is further enhanced on the basis of 5G mmWave. The enhanced sensing function can provide a priori information for the optimal and rapid scheduling of distributed computing power and provide richer data sources for artificial intelligence (AI) services and applications to enhance the robustness of the training model. The E-HFWN can contribute to the development of technologies related to 6G synaesthesia computing integrated networks, promote the consensus between academia and industry.

Abstract Temporary consolidation is a quite common practice during archeological excavations nowadays. Melts of cyclododecane or menthol are among the most used consolidants. When using melting protocol to consolidate fragile heritages in archaeological excavation sites, one of the most frequently encountered challenges is the poor penetration of the melt into the heritages, especially in cases of low environmental temperatures, high water content or compact substrates. In this work, we explore the possibility of using solvent-assisted menthol sols as temporary consolidant. Six common organic liquids are individually introduced into menthol at a concentration of 9.1 wt% to formulate room temperature menthol sols. Their potentials as temporary consolidants are systematically investigated. Experimental data indicate that solvent polarity is the most important feature for temporary consolidation purpose and ethanol with medium polarity is among the most appropriate solvents. Laboratory research results show that much better penetration behavior and good consolidation performances can be achieved in menthol-ethanol sol. The as-prepared menthol-ethanol sol is applied in Liangzhu archeological excavation site with satisfactory outcomes. This work shows that menthol-ethanol sol is an excellent temporary consolidation material for archaeological excavation purpose especially in extremely wet condition.

This paper takes the specific environment covered by vegetation as the research object, carries out modeling and analysis, takes the large-scale fading model of wireless channel as the basis of data processing, researches the transmission law of electromagnetic wave in a typical vegetation environment, which can be divided into four situations. The signal attenuation in each case is theoretically derived and numerically simulated. From the view point of supporting vegetation environment channel, the large-scale channel measurement system is built to meet the actual needs, such as bandwidth, frequency, vegetation coverage, etc. the final vegetation environment channel model under the large-scale fading model is obtained. The results show that the path gain of four scenarios respectively are 81.3 dB, 36.5 dB, 1.6 dB, 1.5 dB, the value of path gain index is within the range of 2~3.5, four scenarios shadow fading standard deviation values are 7.1, 4.8, 10.1, 9.2, reflects the change of received power at the point caused by random factors such as reflection, absorption and scattering. In addition, the proposed channel model improves the gain about 15% compared with the tradition SUI model within vegetation coverage scene. The design process of the proposed model is carried out in the order of "studied the existing foundation → analyzed the existing problems → proposed the optimization scheme → simulation and verification results → actual measurement system". The advantage of paper's method is that, when the signal frequency, transceiver distance, antenna height and vegetation environment characteristic parameters are given, the statistical analysis results of wireless channel data are obtained. The purpose of the proposed work establishes a signal propagation prediction model under the vegetation environment, realizes a theoretical basis for channel simulation, and provides the basis of anti-fading technologies.

A greater understanding of moisture sorption behaviour of aged wooden structural components, which has a close relationship with dimensional stability, is required to effectively evaluate and preserve historical artefacts. This study focused on the effects of aging on Baotou beam samples from a Chinese historical wooden building. An analysis of the sorption isotherms and hysteresis loops of a naturally aged, decayed sample (AOS), an aged sound sample (AIS), and a reference sample (RS), using classical sorption isotherm models revealed that the moisture sorption behaviour of samples from the same growth ring in a Baotou beam can differ significantly. AOS showed higher hygroscopicity than AIS, and both these samples were more hygroscopic than RS. Furthermore, the mono/multilayer moisture contents of AOS were always higher than those of AIS and RS. In addition, Fourier transform infrared, second-derivative infrared, and two-dimensional correlation infrared spectroscopy were used to investigate chemical changes in the samples. The relative hemicellulose and lignin contents of the samples changed significantly with wood aging. Furthermore, AOS exhibited the highest calcium oxalate content, which may be associated with fungal infections. Overall, these results provide valuable insights into the effects of aging on wood samples and the dimensional stability of timber structures, which could inform future research on methods for the preservation or restoration of aging timber structures.