最新刊期
期 1 ， 2023
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摘要：As a new type of green environment-friendly material innovated in China, the reconstituted material (scrimber), which is mainly composed of wood scrimber and bamboo scrimber has initially established a basic theoretical system, process technology equipment system and developed into a large-scale industry production after nearly 20 years. This paper analyzed the scientific problems in the development of reconstituted materials, including the process and mechanism of microstructure reconstruction, the effect of density mechanism on the properties of recombinant materials, etc., as well as the major technical problems, including the technology integration of recombinant units, hot/cold pressing, etc. In addition, the development trends of reconstituted materials in outdoor landscape, home furnishing, flooring, structural materials, and other fields were also discussed in depth.关键词：reconstituted material;bamboo scrimber;wood scrimber;scientific problem;technical problem- 285
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发布时间：2023-03-13 -
摘要：Metal-organic frameworks (MOFs) are an emerging crystal material consisting of inorganic metal ions/clusters and organic ligands, which have attracted much attention due to the structural and functional diversities. However, MOFs mainly exists in the form of powder and crystal because of their intrinsic crystalline nature, severely restricting the practical applications. As a naturally porous material, wood possesses an ordered pore structure, excellent mechanical properties, and rich active groups, making it an ideal carrier for the effective immobilization of powdery MOFs. Integrating MOFs with porous wood to form wood/MOFs composites can effectively combine the functional characteristic of MOFs and the structural features of wood, providing a new avenue to expand the application of MOFs. In this review, current state-of-the-art fabrication methods of wood/MOFs composites are systematically summarized. The latest applications in liquid/gas adsorption, catalysis, electrochemical energy storage, and other emerging fields are highlighted. In addition, current existing problems and future research directions in the field of wood/MOFs composites for advanced functional materials are discussed.关键词：wood;metal-organic frameworks;composite;carrier- 281
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发布时间：2023-03-13 -
摘要：The wood constitutive model is an essential basis for the numerical analysis of timber members. This paper introduces the empirical model based on experiment, elastic model, elastic-plastic model, damage model (elastic damage model, elastic-plastic damage model), fracture model, and strain rate model based on theory. The theoretical basis, characteristics, and application examples of the existing models are emphasized. Furthermore, both advantages and disadvantages of the constitutive model for wood are analyzed. The current issues and problems in the application of the constitutive model are summarized. It is necessary to establish a wood constitutive model considering the effect of the strain rate, which is suitable for the analysis of mechanical properties under dynamic load.关键词：wood;constitutive model;strain rate- 93
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发布时间：2023-03-13
REVIEWS
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摘要：Digital twin technology can effectively solve manufacturing workshop's operation problems, cope with dynamic changes in production, and promote the digital transformation of custom panel furniture manufactures. By introducing the development status and application of digital twin technology, the application feasibilities of digital twin technology in custom panel furniture production workshops were analyzed in combination with the information construction of custom panel furniture and the unique ability of digital twin workshop to solve specific issues. On the basis of proposing the implementation strategy of a digital twin model for custom panel furniture, the related technologies of digital twin workshop construction such as information collection technology, model construction technology, and digital twin system construction were discussed with the aim to making a preliminary exploration for the implementation of digital twin system in the custom furniture industry, which will provide reference for the promotion of comprehensive intelligent manufacturing.关键词：custom panel furniture;digital twin;intelligent manufacturing- 73
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发布时间：2023-03-13 -
摘要：In order to improve the productivity of the sorting process in custom furnishing manufactures, the comprehensive efficiency index and correlation analysis tool were used to evaluate the efficiency loss of sorting process equipment, analyze the main factors that restrict the overall equipment effectiveness(OEE) of sorting process equipment and its relationship. Suggestions were made for the improvement of equipment efficiency by investigating the usage and failure data of intelligent sorting equipment in a furniture manufacture.关键词：custom furnishing;sorting process;overall equipment effectiveness;correlation analysis- 62
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发布时间：2023-03-13
RESEARCH ON PLANNING AND MANAGEMENT FOR HOME FURNISHING DIGITAL WORKSHOP
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摘要：The change in the temperature and moisture distribution in wood is the fundamental mechanism for solid wood sandwich compression formation. In this study, poplar (Populus tomentosa) wood with high moisture content (MC) on surfaces and low MC in the interior was used as the raw material. The poplar wood was preheated by press platens at 180 ℃, to investigate the changes of temperature distribution in wood during the preheating process in order to provide evidence for clarifying the mechanism for wood sandwich compression. It was found that a peak heating rate existed in the thickness direction all the time during preheating. As the preheating time extended, the peak heating rate migrated from wood surfaces to the center. The temperature of high MC area was 6.11~47.58 ℃ higher than the wood glass transition point and thus this area was being softened, which was one of the main reasons for wood sandwich compression formation. A multivariate functional model with a coefficient of determination of 0.985 was built to predict the temperatures along the wood thickness direction. The standard error for the predicted temperatures in wood was 3.21 ℃, suggesting that this model can well predict temperatures in wood.关键词：uneven distribution of MC in wood;heating by heating plates;heating rate;temperature distribution;sandwich compression- 144
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发布时间：2023-03-13 -
摘要：Eucalyptus grandis × E.urophylla boards with 20 mm-thickness were heat-treated under high temperatures of 140 ℃, 160 ℃, and 180 ℃ respectively. Two heating methods were used, including one-step heating and segmented heating. The effect of heating conditions on the temperature change in wood was analyzed. The numerical simulation method was used to construct a three-dimensional heat transfer model for eucalyptus wood during the high temperature heat treatment to investigate its transient heat transfer characteristics and predict the internal temperature distribution. The results showed that a lower target temperature and a segmented heating method could reduce the internal temperature gradient of the wood during the high temperature heat treatment. The accuracy of the numerical simulation results (error<3.0%) was verified by experiment data. The model can predict the central temperature of eucalyptus wood at any time. Thus it provides a basis for the optimization of the high temperature heat treatment process.关键词：Eucalyptus wood;high temperature heat treatment;heat transfer;temperature gradient;Numerical simulation- 163
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发布时间：2023-03-13 -
摘要：The feasibility of predicting the compressive and bending properties was explored based on near-infrared spectroscopy for imported Pinus radiata. The various modeling were compared based on different wood sections, spectral pretreatment methods, and wavebands in different spectral regions respectively. The results showed that the calibration models established by the spectra of the tangential section had the highest accuracy. The calibration models with the original spectra had good accuracy, and the correlation coefficients were 0.85 and above. The correlation coefficient of the compressive strength model treated by S-G convolution smoothing raised to 0.92. The calibration models in the whole wavelength all had the best effect. The external validation of the calibration models showed that the predicted value of the prediction model for the compressive strength parallel to the grain, MOR, and MOE of Pinus radiata had a high correlation with the measured value and the correlation coefficient was 0.82 and above. The results provide a new method for rapid evaluation of the compressive and bending properties in Pinus radiata.关键词：Pinus radiata;near-infrared spectroscopy;prediction model;compressive properties;bending properties- 87
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发布时间：2023-03-13 -
摘要：In order to improve the utilization rate of blue stain wood, composite materials were developed by using the blue stain fungus Lasiodiplodia theobromae and blue-stained wood shavings (Scots pine, rubberwood, and a mixture of both). The effect of the moisture content on the properties of mycelium composites was discussed. The results showed that after 14 days of culture, the surface of the substrates was covered by mycelia, and their colors turned black significantly. The increase in the moisture content of the mat promoted lignin repolymerization and Maillard reaction in the composites, improving the bending strength of the mycelium composites. The bending strengths of the mycelium composites with Scots pine substrate, rubberwood substrate, and mixed substrate were increased by 64%, 221%, and 74% respectively. Compared with the Scots pine, rubberwood was more suitable for the growth of Lasiodiplodia theobromae, and therefore the rubberwood-based mycelium composite showed higher bending strength compared with Scots pine-based mycelium composite. Rubberwood-based substrate mycelium composite meets the strength requirements for low density particleboard (ANSI A208.1-2016 Particleboard). The hydrophobic protein on the surface of the mycelium increased the contact angle and hydrophobicity of the material, but the increase in the moisture content of the mat weakened the hydrophobicity and water resistance of the material. This study provided a new idea for the use of blue-stained wood.关键词：Lasiodiplodia theobromae;blue-stained wood;mycelium composite;bending strength- 65
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发布时间：2023-03-13 -
摘要：As a new product in the fiberboard industry, ultra-thin high density fiberboards have been widely used as veneers for the plywood furnishing, architectural decoration, and other fields because of the ultra-thin thickness (about 1.5 mm). In this study, phenol-formaldehyde resin (PF) was used as an adhesive to investigate the effects of the hot-pressing time (60, 90, and 120 s) and temperature (150, 170, and 190 ℃) on the modulus of rupture, internal bonding strength, and the 24 h water absorption thickness swelling rate (24 h TS) of 1 mm PF ultra-thin fiberboards. The scanning electron microscope was used to observe the bonding situation between fiber and resin. The results showed that with the extension of the hot-pressing time and the increase of hot-pressing temperature within a certain range, the performance of fiberboards was gradually improved. When the hot-pressing time was 120 s and the hot-pressing temperature was 190 ℃, the performance of fiberboards was the best. The modulus of rupture reached 88.5 MPa. The internal bonding strength reached 5.70 MPa and the 24 h TS was 6.8%. These properties meet the requirements of the standard T/CNFPIA 3007—2019 Ultra-Thin High Density Fiberboard.关键词：ultra-thin high density fiberboard;phenolic resin;hot pressing conditions;modulus of rupture;24 h water absorption thickness swelling rate- 113
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发布时间：2023-03-13 -
摘要：In order to improve image qualities of veneer knots, including the contrast, detail sharpness, and color fidelity , an image enhancement algorithm combining adaptive correction and unsharpening mask technology was proposed. The brightness (V) component and saturation (S) component were extracted from the HSV space of separable color information. The weighted distribution adaptive gamma correction and adaptive nonlinear stretching processing were used to improve the contrast and keep the color natural. Finally, unsharpened mask technique was used to enhance the sub-detail area around knots. Experiment results showed that this algorithm could effectively improve the contrast and detail definition of the veneer images, and the image color was more natural. The defects of knots were more prominent and more details of knots were retained. Compared with AGC-Quantile and histogram equalization algorithms, these algorithms have better mean square error, peak signal to noise ratio, and structural similarity index.关键词：veneer knot;adaptive gamma correction for weighted distribution;adaptive nonlinear tension;unsharpened mask;image enhancement- 44
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发布时间：2023-03-13 -
摘要：China’s ancient buildings are characterized by wooden structures, using a large number of wood components inside. Wood components are the basic units and elements of ancient buildings. The biological properties of wood components are easily rotted by fungi and insects, which shorten service life and affect the safety of wooden structures. The rotted old wood components have to be replaced, resulting in the loss of historical information. Therefore, it is urgent to establish a biological hazard prevention-and-protection system for wood components and develop prevention and protection technologies, in order to prolong the service life of wood components and better inherit Chinese traditional architectural civilization culture. This paper summarizes the information on wood species and reasons and risks of biological hazards of traditional building wood components. The framework of biological hazard prevention-and-protection system was proposed for ancient building wood components in China on the basis of the risk management system of immovable cultural heritage against natural hazards with risk assessment, risk monitoring, risk prevention, and emergency management. At last, the further research focusing on the prevention and protection is also discussed.关键词：ancient buildings;wood components;biological hazard;biological risk;risk management;prevention-and-protection system- 178
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发布时间：2023-03-13 -
摘要：To realize the curved groove structure design of the ultra-thin circular saw blade, the curved groove structure of the circular saw blade were optimized by combining topology optimization based on variable density method and shape optimization based on the pattern search algorithm. Using topological optimization based on the variable density method to determine the location of curved groove. The overall amplitude of the circular saw blade was taken as the evaluation criterion, the design domain derived from the topological optimization was taken as the boundary condition. The shape of the curved groove structure of the circular saw blade was optimized by the pattern search algorithm. The optimum solution of groove position, structure, and shape of circular saw blade was obtained under given constraints and loads. The importance of the shape of the curve slot on the axial vibration of the saw blade was further proved in the test.关键词：ultra-thin circular saw blade;curve groove;topology optimization based on variable density method;shape optimization based on the pattern search algorithm;structure design- 37
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发布时间：2023-03-13 -
摘要：In order to improve the current diameter measurement method of the automatic bamboo-ripping machine, which is not universal and difficult to achieve thickness measurement simultaneously, this study uses YOLOv4-Tiny and MobileNet-SegNet to form a cascade network, applies binocular vision to measure distance, and conducts the minimum circumcircle to obtain outer diameter and thickness, and constructs a measurement algorithm. The measurement system uses a USB binocular camera as an imaging device to connect Raspberry pi 4B and Movidius neural compute sticks. The main program is written in Python, and the model is deployed by OpenVINO in asynchronous mode. The measurement were carried out at different distances, angles, and bamboo tube specifications. The results show that the optimal measurement distance of the algorithm is 30~40 cm, the average relative error of bamboo outer diameter measurement is 1.43%, the average relative error of thickness measurement is 8.76%, and the detection speed is 7.1 FPS. This study provides a basis for the design of the automatic bamboo-ripping machine with a diameter measuring and tool changing system.关键词：bamboo-ripping machine;measurement of bamboo diameter;YOLOv4-Tiny;MobileNet-SegNet;asynchronous inferring- 46
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发布时间：2023-03-13
RESEARCH PAPERS
- Address：Box 29，Research Institute of Wood Industry, No. 1, Dongxiaofu, Haidian District, Beijing Postal code：100091
- Tel：010-62889419 Email：mckx@caf.ac.cn
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