最新刊期
卷 40 ， 期 2 ， 2026
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摘要：The mechanical properties of wooden components from ancient buildings are closely related to the dynamic evolution of their chemical components and microstructure. To investigate the deterioration mechanism of material properties, this study took the eave purlin of Guhuaxuan in the Palace Museum as the research object. Multi-scale characterization methods, including Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), and scanning electron microscopy (SEM), were used to analyze the degradation characteristics of cellulose, hemicellulose, and lignin. The correlations between these components and mechanical properties such as density and modulus of elasticity (Ed) were explored, and the gradient deterioration patterns along the eave purlin at different positions relative to the wall (near column, mid-span, and near wall) were analyzed. The results showed that although the eave purlin was free from direct sunlight and generally well-ventilated, its mechanical deterioration still exhibited significant positional differences: the deterioration degree at the mid-span (D) was slightly higher than that at the near-wall end (G), and the near-column end (A) showed the slightest deterioration. Cellulose and hemicellulose degrade significantly at the near-wall end. α-cellulose had the most significant effect on the mechanical properties, with a correlation coefficient of r=0.91 (R²=0.83) for Ed, and the decrease in its crystallinity directly led to the deterioration of density and Ed. The local microenvironment was found to be the core factor driving the differential deterioration of wooden components at different positions. This study revealed the interactive actions between chemical component degradation and microstructure evolution during the deterioration of wooden components under conditions free of direct sunlight and with good ventilation, providing a quantitative evaluation framework for the restoration of ancient architectural wood components based on cellulose crystallinity and chemical degradation.关键词：ancient architecture conservation;Guhuaxuan in the Palace Museum;deterioration mechanisms;modulus of elasticity;wood chemical components;microstructure130|11|0更新时间：2026-06-03
KEY SCIENTIFIC RESEARCH BASE OF HISTORICAL BUILDING WOOD
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摘要：Banana (Musa acuminata) pseudostem fibers were used as the raw material which were prepared through pre-alkali soaking, high-temperature alkaline cooking, and hydrogen peroxide bleaching. Papers were then prepared by blending banana pseudostem fibers with bamboo pulp fibers. The effects of the beating degree and banana pseudostem fibers dosage on the mechanical properties and reinforcement mechanism of paper were investigated. The results demonstrated that the banana pseudostem fibers exhibited good separation. The fiber morphological parameters of banana pseudostem fibers and bamboo pulp fibers were significantly changed with increasing of beating degree (P＜0.05). Their average length ranged from 2.65 to 2.99 mm, average width from 20.6 to 21.4 μm, and average length-to-width ratio from 127.4 to 145.1. Notably, the cellulose content and crystallinity of banana pseudostem fibers were 88.4% and 78.0%, respectively. When banana pseudostem fibers (37 °SR, 20%~30%) were mixed with bamboo pulp fibers (40 °SR), the properties of paper were improved compared with pure bamboo pulp paper. Specifically, the tensile index increased by 3.1%~7.0%, the tear index by 15.4%~30.3%, the burst index by 27.6%~27.8%, and the folding endurance by a factor of 1.3~1.6 (P＜0.05). The wettability and air permeability of paper were reduced. The long fibers from banana pseudostem provided flexibility and acted as a skeletal support, while the short fibers from bamboo pulp filled voids and defects to reduce the probability of stress concentration. The“long-short”complementary multi-scale three-dimensional intertwined structure imparted both stiffness and strength to the paper. Furthermore, the overall structure formed by the three-dimensional entanglement of microfibers at the microscopic scale endowed the composite paper with good strength. Banana pseudostem fibers could serve as one of the biomass blending raw materials for high-performance paper, effectively improving the physical strength of bamboo pulp paper, thereby providing a scientific basis for the high-value utilization of agricultural waste resources from banana pseudostems.关键词：banana pseudo-stem;bamboo pulp;fiber blending;paper strength98|4|0更新时间：2026-06-03 -
摘要：To address issues such as insufficient sustainability and high raw material costs of isocyanate adhesives in manufacturing of wood-based panels, while further expanding their environmental friendliness, this study used urea-based hyperbranched amino resin (UHA) and biomass-derived citric acid (CA) as composite modifiers to synergistically modify polymeric methylene diphenyl diisocyanate (pMDI) adhesives. A ternary wood adhesive (UCM) was successfully developed and applied in the production of three-layer Eucalyptus plywood. The influence of UHA addition amount on the microstructure, physical and chemical properties, chemical structure of UCM, as well as the bonding strength of UCM plywood was investigated. The results indicated that the optimal compounding process for the UCM adhesive was a UHA-CA-pMDI mass ratio of 7∶2∶1 (with the pMDI content being only 10%), and the various components of the adhesive form an effective cross-linked network, enhancing the adhesive's cohesion and interface bonding strength. The optimal process conditions for preparing the glued specimens using this adhesive system are a hot-pressing temperature of 180 °C, a hot-pressing time of 8 minutes, and a hot-pressing pressure of 1.5 MPa. Under this condition, the plywood could comply with with the standard GB/T 9846—2015“Plywood for general use”. The dry strength, cold water strength (after immersion in water at 20 ± 3 °C for 24 hours), hot water strength (after immersion in water at 63 ± 3 °C for 3 hours), and boiling water strength (after immersion in boiling water for 3 hours) of the specimens were 1.24 MPa, 1.26 MPa, 1.08 MPa, and 0.92 MPa, respectively. This study effectively reduced the usage of pMDI adhesive, demonstrating excellent economic benefits and providing new ideas for the development of new low-cost adhesives.关键词：isocyanate adhesive;hyperbranched polymer;citric acid;three-layer plywood;bonding strength203|17|0更新时间：2026-06-03 -
摘要：With the continuous development of the particleboard industry, its major applications have expanded beyond traditional furniture panels to emerging markets such as wall panels, large-size countertops, and tall door boards. These new applications impose higher requirements for low-density yet high-strength particleboards. To address the structural characteristics of the surface and core layers in three-layer particleboard, a synergistic double-layer polyurethane adhesive modification strategy with epoxidized soybean oil and isocyanate was proposed. Three-layer particleboards with target densities of 0.50, 0.55, and 0.60 g/cm³ were manufactured from poplar (Populus sp.) particles of different geometries. In the control group, both the surface and core layers were bonded with polymeric methylene diphenyl diisocyanate (pMDI). In the development group, the surface layer was bonded with a high-strength epoxidized soybean oil-modified polyurethane adhesive (EPA), while the core layer was bonded with a lightweight foamable polyurethane adhesive (FPU). The mechanical properties, including modulus of rupture (MOR), modulus of elasticity (MOE), and internal bond strength (IB), as well as the 24 h thickness swelling and water absorption, were evaluated. In addition, scanning electron microscopy (SEM) was used to examine the microstructure and adhesive distribution in the panels, so as to elucidate the mechanisms by which the adhesives regulated panel performance. The results showed that, at all three low-density levels, the modified particleboards achieved a synergistic improvement in both weight reduction and performance enhancement. In particular, the modified particleboards with a density of 0.55 g/cm³ (10% adhesive content and gradient hot pressing at 190 °C) exhibited MOR, MOE, and IB values of 12.33 MPa, 1 710 MPa, and 0.54 MPa, respectively, meeting the requirements for Type P2 particleboard specified in the Chinese national standard GB/T 4897—2015 Particleboard. Microscopic observations revealed that a three-dimensional porous cross-linked network was formed in the core layer of the modified particleboards, which was the key to achieving both low density and high strength. Overall, the synergistic double-layer pMDI-based adhesive modification strategy not only reduced pMDI consumption, but also improved the overall performance of the particleboards, thereby providing a feasible technical route for manufacturing lightweight high-strength particleboards.关键词：lightweight high-strength particleboard;epoxidized soybean oil;foamable polyurethane adhesive;isocyanate adhesive;3D porous crosslinked network146|8|0更新时间：2026-06-03 -
摘要：Bamboo scrimber (BS), due to its excellent mechanical properties, has been increasingly utilized in the construction industry. However, as a structural material, the degradation mechanism of BS under cyclic freeze-thaw treatment is not yet clear. This study investigated the failure modes, elastic modulus, and compressive strength of BS specimens subjected to 0, 20, 40, and 60 freeze-thaw (F-T) cycles (each cycle comprising freezing at －20 ℃ for 8 hours followed by thawing in water at 20 ℃ for 8 hours) under three loading directions, i.e., parallel-to-grain loading, perpendicular to grain I loading (perpendicular to the glue layer), and perpendicular to grain II loading (parallel to the glue layer). The results indicated that while F-T cycling did not change the failure modes type of the specimens, it significantly altered the proportions of different failure modes. Notably, the proportion of glue layer cracking increased remarkably with increasing F-T cycles from 0 to 60 (from 30% to 64%). Both elastic modulus and compressive strength decreased with an increasing number of F-T cycles across all loading directions, with a decrease of 38.3% and 35.2% in the perpendicular to grain II direction, respectively. Finally, the design characteristic value (0.05 quantile) of the compressive strength of BS was determined based on the statistical analysis of experimental data, and an attenuation model (R2＞0.95) of compressive performance with varying numbers of freeze-thaw cycles was established to provide data support for the reliability design of BS structures in cold regions.关键词：bamboo scrimber;cyclic freeze-thaw treatment;failure modes;elastic modulus;compressive strength;degradation model99|8|0更新时间：2026-06-03 -
摘要：This study investigated the effect of microwave pretreatment time on the dimensional stability and bending properties of compression-densified wood (referred as densified wood). Paulownia tomentosa was pretreatment by microwave, then softened by urea solution (mass fraction of 30%), and followed by hot-pressing to produce densified wood. The results showed that when the hot pressing temperature was 170 ℃, the weight percent gain and density of densified wood significantly increased (P<0.01) with the extension of microwave pretreatment time. Compared with untreated wood, these two indexes were increased by 7.42%~136.13% and 10.71%~39.29%, respectively, with the density profile becoming relatively uniform. Microwave urea synergistic treatment significantly improved the dimensional stability of densified wood (P<0.01). When the microwave pretreatment time was 10~50 s, the set recovery rate and swelling efficiency were decreased by 44.95%~60.81% and 31.08%~50.00%, respectively, compared with control group (treated only by hot-pressing). Both bending strength and modulus of elasticity of densified wood were initially increased and then decreased with the extension of microwave pretreatment time, reaching their maximum at a microwave pretreatment time of 40 seconds (critical time), which increased by 45.45% and 37.62%, respectively, compared with untreated wood (P<0.05). The combined effect of microwave-urea was demonstrated, i.e., microwave treatment induced puffing within the wood, allowing the urea solution to fully penetrate the wood cell walls. During hot-pressing, urea softened and crosslinked with the cell walls, effectively reducing the set recovery rate of densified wood and improving its bending performance. The research results could provide a theoretical basis for the preparation and application of high-performance densified wood.关键词：microwave pretreatment;urea;compression-densified wood;cell wall;dimensional stability;Bending property77|6|0更新时间：2026-06-03 -
摘要：To address the insufficient dimensional stability of thin solid wood flooring for ground heating system, including gaps, warping, cracking, and cupping caused by changes in ambient humidity. 12 mm thick Pometia pinnata wood was used as the material, pressure heat treatment was carried out at 230 °C, 240 °C, and 250 °C for 7 min to modify the wood, which was then fabricated into thin solid wood flooring for ground heating system. The mass loss rate, chemical structure changes, surface wettability, dimensional stability, and mechanical properties of the wood, as well as the dimensional stability, thermal conductivity, and coating properties of the flooring, were evaluated. The results showed that pressure heat treatment had only a minimal effect on the mass loss rate of the wood, with the mass loss rate remaining below 2.47% even at 250 °C. Pressurized heat treatment significantly reduced the equilibrium moisture content, water absorption, and swelling rate of the wood (P<0.05), and these values decreased with increasing treatment temperature. This was attributed to the reduction in hydrophilic functional groups and moisture adsorption sites, as well as the increase in cellulose crystallinity induced by pressure heat treatment. In addition, pressure heat treatment at different temperatures caused varying degrees of microscopic damage to the cell walls, but had little effect on the mechanical properties of the wood. Compared with the control group, the test flooring exhibited significantly improved moisture-resistant and heat-resistant dimensional stability (P< 0.05), meeting the requirements of the Chinese Standard GB/T 35913—2018 “Technical requirements of solid wood flooring for ground with heating system”. The thermal conductivity reached 11 °C·h-1, satisfying the technical requirements of the Chinese Standard GB/T 41547—2022 “Wood-based flooring for underfloor heating”. The coating adhesion, hardness, and wear resistance showed no significant differences from those of the control group and met the premium-grade requirements specified in the Chinese Standard GB/T 15036—2018 “Solid wood flooring-Part 1: Technical requirements”.关键词：thin solid wood flooring;ground heating system;Pometia pinnata wood;pressure heat treatment;dimensional stability;thermal conductivity104|1|0更新时间：2026-06-03 -
摘要：Load-bearing structural insulated panels (SIPs) were fabricated using thick plywood made of rotary-peeled from radiata pine (Pinus radiata) veneer as the sheathing material and expanded polystyrene (EPS) foam as the insulation core. Four groups of full-scale SIP specimens were designed according to two sheathing material thicknesses, 30 and 60 mm, and the presence or absence of EPS core infill. Monotonic and reversed cyclic loading tests were conducted to investigate the failure modes of the SIP specimens and to determine key performance parameters, including ultimate load, shear strength, stiffness, ductility, and energy dissipation capacity. The results showed that: 1) increasing the thickness of the sheathing material enhanced the load-bearing capacity and stiffness of the SIPs. Under the monotonic loading, the ultimate load of SIP specimens with 60-mm-thick sheathing material was 1.88 times that of specimens with 30-mm-thick sheathing material when filled with EPS, and 1.77 times that of specimens without EPS infill; 2) EPS infill effectively improved the ductility and energy dissipation capacity of the SIP specimens. Under the monotonic loading, the energy dissipation of the EPS-filled SIP specimens was 2.02 times that of specimens without EPS infill for the 60-mm-thick sheathing material group. Under the reversed cyclic loading, the energy dissipation of the EPS-filled SIP specimens was 1.67 times that of specimens without EPS infill for the 60-mm-thick sheathing material group; 3) EPS changed the failure mode from localized brittle tearing around bolt holes in the sheathing material to progressive mixed damage at multiple locations, including the stud-sheathing material interface and the stud-bottom plate connections, thereby improving the structural integrity; 4) under the reversed cyclic loading, the ultimate load-bearing capacity of the SIP specimens was generally lower than that obtained under monotonic loading, and asymmetric mechanical behavior was observed in the push and pull directions. This study demonstrated that the thickness of the sheathing material was a critical factor affecting the lateral racking performance and deformation capacities of SIPs, while EPS infill was a key measure for improving ductility and energy dissipation capacity. The combined use of increased sheathing material thickness and EPS infill could synergistically enhance the lateral racking performance of SIPs, providing experimental support and design reference for the application of such components in mid- and high-rise buildings and other scenarios with high load-bearing requirements.关键词：thick plywood;rotary-peeled veneer;lateral racking performance;structural insulated panels;sheathing material;insulation core81|0|0更新时间：2026-06-03 -
摘要：To address the problem of low wood utilization rate and difficulty in balancing the mechanical properties of components during the cutting process of solid wood furniture, an improved genetic algorithm that integrates a texture-mechanics mapping model and a dynamic segmentation strategy was proposed. The method quantifies the relationship between wood grain direction and component bending strength, incorporating this mechanical performance indicator into the fitness function of the improved genetic algorithm. Bézier curves were applied for contour fitting and dynamic computer numerical control path planning to enable high-precision and efficient processing of specially shaped components. Furthermore, an adaptive mutation operator was introduced to balance global exploration and local optimization capabilities. Experiments results based on actual enterprise panel and components data demonstrated that, compared to manual allocation, commercial software and a standard genetic algorithm, the improved genetic algorithm increased the wood utilization rate to 92.3%, achieved a grain orientation matching rate of 95.2%, and improved the average component flexural strength by 17.6% (P<0.01), and controls the algorithm convergence time within 8.2 minutes, meeting production requirements. The ablation experiment further verified the necessity and collaborative effect of each module in the improved genetic algorithm. This research provided a feasible solution for achieving efficient resource utilization and collaborative optimization of product performance in the cutting process of solid wood furniture.关键词：solid wood furniture;irregular component;genetic algorithm;wood grain;mechanical properties;allocation optimization;smart manufacturing64|9|0更新时间：2026-06-03 -
摘要：Surface-decorated wood-based panels serve as a core raw material in the furniture industry, and surface defect detection is a critical step in quality control. Current detection methods commonly adopt YOLO-based machine vision, yet their performance in terms of precision and recall leave room for improvement. In resource-constrained deployment scenarios, the balance between inference speed and detection accuracy remains unresolved. To enhance the overall performance of existing detection models and apply the algorithm to surface defect detection of decorated wood-based panels, this study proposed an improved YOLO11-SDP (You Only Look Once11-Surface Decorated Panels) detection model. The original detection model was improved via three complementary measures: performing Mosaic augmentation on the dataset, replacing the original Feature Pyramid Network (FPN) module with a BiFPN module, and introducing a scale weight factor into the loss function. Experimental results showed that the improved model achieved a precision of 98.0% and a recall of 91.3%. Compared with the original model, the precision and recall rate were increased by 6.8% and 6.1%, respectively. These three enhancements significantly improved the model's capacity to detect small targets, yielding greater generalization and robustness. When balancing the performance gains against the increased computational cost, the scale weight factor was proved superior to BiFPN, followed by Mosaic augmentation. Furthermore, the detection speed satisfied real-time processing requirements. Consequently, the YOLO11-SDP model was well-suited for the online detection of common defects—including frosting mark, water mark, spots, and crack—in the manufacturing of surface decorated wood-based panels, thereby providing technical support for the high‑quality development of home furnishing and building materials.关键词：surface-decorated wood-based panels;surface defects detection;YOLO11-SDP;Computer vision;Model precision119|12|0更新时间：2026-06-03
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