Hajir Al-musawi, Gerhard Emsenhuber, Bernhard Ungerer, Georg Baumann, Florian Feist, Ulrich Müller
{"title":"Development of swelling pressure in paulownia and Norway spruce during moisture absorption","authors":"Hajir Al-musawi, Gerhard Emsenhuber, Bernhard Ungerer, Georg Baumann, Florian Feist, Ulrich Müller","doi":"10.1007/s00107-025-02204-4","DOIUrl":"10.1007/s00107-025-02204-4","url":null,"abstract":"<div><p>Wood hybrid materials have gained significant attention for advanced technical applications over the past decade. In contrast to other materials, wood’s hygroscopic nature causes swelling and shrinkage, leading to differential expansion in hybrid systems under varying humidity conditions. When wood’s swelling is restrained by surrounding materials, stresses develop within both the wood and its adjacent components. To study this phenomenon, swelling tests were conducted on kiln-dried paulownia (<i>Paulownia elongata</i>) and Norway spruce (<i>Picea abies</i>) in a climate chamber at 20 °C and 98% relative humidity, with expansion restricted in one direction. Moisture absorption initially exhibited a steep, linear increase, levelling off after approximately 2 h. Swelling pressures rose sharply, peaking after 30 h for paulownia and 19 h for spruce, before gradually decreasing due to increased moisture content and relaxation. The measured stresses were lower than the compressive strengths of both wood species at their respective moisture contents. Microscopic examinations showed no cellular damage in paulownia during moisture absorption due to swelling pressure. In contrast, spruce wood displayed cell wall deformations and ray’s kinking in the early wood region of radial samples, as well as cell wall bending in tangential samples. This indicates that maximum stress is determined by the localised failure of the wood’s cellular structure rather than its overall properties. Such local effects were more pronounced in spruce than in paulownia due to their different structure. As a result, paulownia shows excellent potential for use in hybrid structures due to its low swelling and shrinkage properties and uniform structure.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":"83 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00107-025-02204-4.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143109149","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Tool condition monitoring strategies from metal cutting: insights for optimizing wood-based material processing","authors":"Yu-tang Chen, Jiao-hao Tian, Xiao-lei Guo, Bin Na","doi":"10.1007/s00107-024-02198-5","DOIUrl":"10.1007/s00107-024-02198-5","url":null,"abstract":"<div><p>Tool condition monitoring (TCM) is essential for advancing the wood-based material processing industry, particularly in the context of rapid technological progress. Unlike metal cutting, wood-based material cutting presents unique challenges that require existing TCM systems to be carefully adapted. Despite its importance, research specifically targeting TCM in wood-based processing remains sparse, with most studies focusing on cutting mechanisms rather than monitoring solutions. This paper offers a comparative analysis, synthesizing insights from cutting mechanisms and TCM to address this gap. It further explores the broader integration of TCM into wood processing, highlighting current challenges and limitations. By bridging these knowledge gaps, the study provides a foundation for improving TCM applications in wood-based material cutting.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":"83 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-01-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143109150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Basalt grid reinforcement of lightweight plywood","authors":"Marcus Cordier, Carsten Mai","doi":"10.1007/s00107-024-02196-7","DOIUrl":"10.1007/s00107-024-02196-7","url":null,"abstract":"<div><p>By using basalt fibre grids as a reinforcing material, lightweight plywood with improved bending properties could be produced by using low density hardwood veneers and phenol-formaldehyde (PF) adhesives. The improvement in flexural strength would allow it to be used in a wider range of load-bearing applications. In this study, acrylate-coated basalt fibre grids with a grammage of 200g m<span>(^{-2})</span> and uncoated basalt fibre grids with a grammage of 116g m<span>(^{-2})</span> were inserted into the outer glue joints of five-layer lime (<i>Tilia cordata</i>) plywood as reinforcement. The plywood was bonded with two formulations of PF adhesive. The evaluation of the mechanical properties showed increases for the modulus of rupture (MOR) and the modulus of elasticity (MOE). The increase in MOR was up to 25% in the parallel direction of the top layers and up to 49% in the perpendicular direction of the top layers for plywood reinforced with the acrylate-coated basalt fibre grid compared to the unreinforced reference in a raw density-adjusted comparison. After treatment to evaluate moisture resistance under cyclic test conditions (MR), the reinforced plywoods exhibited similar bending strength to the unreinforced reference after standardised climate conditioning. At the same time, the addition of coated basalt fibre grid had no effect on surface soundness (SS). Therefore, the use of coated basalt grid as a reinforcing material could be a good way to produce high-strength plywood using low-density hardwood veneers.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":"83 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-01-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://link.springer.com/content/pdf/10.1007/s00107-024-02196-7.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142995125","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Wanzhao Li, Yunfeng Shi, Wujun Hong, Juwan Jin, Changtong Mei
{"title":"In situ structural changes of voids in OSB in three-point bending test","authors":"Wanzhao Li, Yunfeng Shi, Wujun Hong, Juwan Jin, Changtong Mei","doi":"10.1007/s00107-024-02194-9","DOIUrl":"10.1007/s00107-024-02194-9","url":null,"abstract":"<div><p>Oriented strand board (OSB) is widely used in construction due to its cost-effectiveness and good mechanical performances. While the relationship between processing parameters and void formation has been extensively studied, the real-time behavior of voids during mechanical loading remains poorly understood. This study investigated the dynamic relationship between void characteristics and mechanical properties of OSB using digital image correlation (DIC) technology during the three-point bending tests on 15 mm and 18 mm thick commercial panels. Results showed that the initial void sizes in the core and face layers averaged 0.019 mm² and 0.017 mm² respectively, with voidage being significantly higher in the core layer than in the face layers. The size of voids hardly changes when the loading force is lower than 0.7 times of the maximum loading force. Shear strain analysis revealed that structural changes were more pronounced in and around voids compared to other regions, especially in the core layer along the major axis. Fracture initiation was primarily associated with individual voids in face layers and areas of high void concentration in the core layer. Notably, continuous and large fractures enhance the specimen’s load-bearing capacity, resulting in high MOE and MOR values. Non-continuous fractures in the core layer, however, have limited contribution to increasing MOE and MOR of the specimens.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":"83 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994374","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Yanglin Ge, Jianxiong Lyu, Xingong Li, Xiaofeng Hao, Jianzheng Qiao, Kang Xu, Yiqiang Wu, Xianjun Li
{"title":"Experimental investigations and model validation of compression rheological behavior in bamboo scrimber during the hot-pressing process","authors":"Yanglin Ge, Jianxiong Lyu, Xingong Li, Xiaofeng Hao, Jianzheng Qiao, Kang Xu, Yiqiang Wu, Xianjun Li","doi":"10.1007/s00107-025-02200-8","DOIUrl":"10.1007/s00107-025-02200-8","url":null,"abstract":"<div><p>The current study investigated the rheological behavior of a heat-treated and phenolic resin-impregnated bamboo bundle slab during the hot-pressing process. These findings have significant implications for advancing hot-pressing technology, conserving energy, and reducing emissions in the bamboo scrimber industry. The results revealed that stress relaxation played a dominant role in the hot-pressing process after reaching the target thickness of the slab, which was influenced by compression deformation stress, hygrothermal stress, and phenolic resin polycondensation. Higher hot-pressing temperature and initial moisture content (IMC) led to increased hygrothermal stress, causing delayed stress relaxation. Increasing target thickness or reducing target density could alleviate hygrothermal stress while phenolic resin curing facilitated stress relaxation by constraining compression deformation. Both the three-element generalized Maxwell model (average R<sup>2</sup> = 0.95) and the five-element generalized Maxwell model (average R<sup>2</sup> = 0.98) effectively described the slab stress relaxation; however high IMC caused excessive vapor pressure, leading to unsatisfactory fitting of the stage.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":"83 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994794","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Achieving maximum strength in oak wood (Quercus robur, L.) bonding: techniques for surface preparation and adhesive application","authors":"Tomislav Gržan, Andrija Novosel, Vedrana Špada, Goran Mihulja, Vjekoslav Živković","doi":"10.1007/s00107-024-02179-8","DOIUrl":"10.1007/s00107-024-02179-8","url":null,"abstract":"<div><p>The growing use of wood in construction, driven by architectural trends favouring smaller cross sections, often compromises the material's physical and mechanical properties, especially in hardwoods like oak, which are prone to instability and moisture-related deformations. To counteract these issues, researchers have developed reinforced wood products that incorporate materials such as steel, aluminium, carbon fibre reinforced polymer (CFRP), glass fibre reinforced polymer (GFRP), and basalt fibres, which enhance strength and stability while reducing dimensional changes. Despite these advances, there is limited research on optimal bonding techniques, particularly surface preparation, which is crucial for effective gluing. To address this gap, this study aims to determine the most suitable mechanical surface preparation and adhesive to achieve satisfactory gluing of oak to oak. Understanding the optimal surface preparation and bonding techniques is a crucial first step before exploring the incorporation of nonwood implants in the next phase of research. Therefore, this study investigates the influence of three surface machining methods (planing, sanding, and face milling) on the performance of bonded Slavonian oak joints (<i>Quercus robur</i>, L.) in dry and artificially aged state (AA). The various machined surfaces were tested using five adhesives: polyvinyl acetate (PVAC), 1k polyurethane (PUR1), fibre-reinforced polyurethane (PUR2), 2k polyurethane (PUR3), and epoxy adhesive (ER). The surface properties of the wood and the bonding properties of the glued wooden joints were measured. The wetting angle was tested according to EN 828, the surface energy was calculated according to the Wu and OWRK methods, while the compressive shear strength test samples were prepared and tested according to the ISO 6238 standard in the dry and AA state. Visual designation of the main failure patterns and scanning electron microscopy (SEM) of adhesive line integrity and adhesive penetration were also used to evaluate the joint bonding properties. The sanded surface results in the best wettability and the highest surface energy, which may be attributed to changes in surface morphology and structure of chemical components on the wood surface. The strength of PVAc glued joints was affected only by different machining, ER and PUR1 were affected by different machining and/or by AA, while PUR2 and PUR3 were affected neither by different machining nor by AA. PUR types of adhesives have proven to be the most suitable for bonding moisture-resistant face-milled, planed, or sanded joints.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":"83 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-01-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994373","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Delfina Godinho, Ana Lourenço, Solange de Oliveira Araújo, José Saporiti Machado, Lina Nunes, Marta Duarte, Sónia Duarte, Cristina Ferreira, Teresa Quilhó, Teresa C. Diamantino, Jorge Gominho
{"title":"Thermally modified wood: assessing the impact of weathering on mechanical strength and exposure to subterranean termites","authors":"Delfina Godinho, Ana Lourenço, Solange de Oliveira Araújo, José Saporiti Machado, Lina Nunes, Marta Duarte, Sónia Duarte, Cristina Ferreira, Teresa Quilhó, Teresa C. Diamantino, Jorge Gominho","doi":"10.1007/s00107-024-02199-4","DOIUrl":"10.1007/s00107-024-02199-4","url":null,"abstract":"<div><p>The main objective of this study was to evaluate the mechanical properties of three thermal-modified wood species when exposed to weathering in urban and maritime/industrial environments and their durability against subterranean termites. The wood species studied were Maritime pine, ash, and blackwood acacia. All wood samples were exposed to two different environments (urban and maritime/industrial) for 24 months. Then, its physical and mechanical properties were evaluated (modulus of elasticity (MOE), modulus of rupture (MOR), compression strength (CS), and modulus of compression (MOC). Thermally modified woods revealed a lower density, which could explain the loss of MOE and MOR. In compression, no significant changes were verified. The weathered samples showed changes in mechanical properties, mostly verified in MOE and MOR, where some decreases were reported in both locations. Tests were performed to evaluate biodegradation and the resistance of all wood samples to subterranean termites. The grade of attack (≈4) and termite survival rate were similar in all wood species (above 75% and lower than 80%), except for modified acacia (59%), which could indicate that thermal modification increased toxic substances. The cellulose degradation was reflected in FTIR-ATR and Py-GC/MS in natural and thermally modified woods. Py-GC/MS showed a decrease in levoglucosan, while lignin suffered some modifications with slight changes in monomeric composition reflected by the reduction of the S/G ratio. No changes were found between the two environments, and thermal modification did not give extra protection against termites and weathering.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":"83 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976598","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chunmei Yang, Tingting Wang, Xinchi Tian, Jie Yan, Bo Xue, Chengwen Sun
{"title":"The mechanism of moisture transport and mechanical model of ultra-thin fiberboard","authors":"Chunmei Yang, Tingting Wang, Xinchi Tian, Jie Yan, Bo Xue, Chengwen Sun","doi":"10.1007/s00107-024-02186-9","DOIUrl":"10.1007/s00107-024-02186-9","url":null,"abstract":"<div><p>As a new type of green and low-carbon biomass composite material, ultra-thin fiberboard has received great attention in the market. However, due to the complexity of the hot pressing process, it is not easy to quantitatively analyze the influence of hot pressing parameters on the properties of ultra-thin fiberboard. This study investigated the relationship between the temperature and time of hot pressing, and the physical and mechanical properties of fiberboard through the mechanism of moisture transfer. A mathematical model for temperature, time, and moisture content was established, as well as a neural network prediction model for the influence of moisture content on the physical and mechanical properties of the board. An ultra-thin fiberboard heat and mass transfer model was built according to the heat and moisture transport mechanism. Fluent software simulation was used to determine the moisture content of the boards under the matching hot pressing process. This study helps to optimize the hot pressing process and improve the product quality and production efficiency of ultra-thin fiberboard.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":"83 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-01-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142994422","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Machine learning-based prediction of processing time in furniture manufacturing to estimate lead time and pricing","authors":"Abasali Masoumi, Brian H. Bond","doi":"10.1007/s00107-024-02177-w","DOIUrl":"10.1007/s00107-024-02177-w","url":null,"abstract":"<div><p>Furniture manufacturing plants are mainly small to medium enterprises (SMEs) and must merge customized mass production into their schedule to meet the market demand. Furniture plants produce a diverse array of models, with each process uniquely adding to the costs. In this multiproduct, multipart and multi-process manufacturing, it is difficult to accurately predict the processing time of new models and the lead time for highly customized orders. The processing time of parts is critical for optimizing, estimating the lead time and pricing the products, particularly for new models. Machine Learning (ML) is a useful tool to analyze and control manufacturing parameters and could be applied to furniture factories too. In this study the authors demonstrated the use of a ML-based framework to predict the processing time of wooden furniture based on the design of parts and actual manufacturing data. Specifically, the objectives are to define the accuracy of Convolutional Neural Networks (CNN) in classifying furniture parts according to their design characteristics into categories such as Plain, 2D, and 3D curved, and define the accuracy of Artificial Neural Networks (ANNs) in taking CNN data along with real manufacturing processing time data for identifying and analyzing intricate correlations between parts and manufacturing processes, thereby facilitating precise prediction of processing time. Images of the furniture’s parts design and data from a time and motion study in mass production in a plant were used to develop the models. The models' R<sup>2</sup>, Mean Squared Error (MSE) and Mean Absolute Percentage Error (MAPE) were calculated as a criterion for defining accuracy. Random Forest and Gradient Boosting regression models were developed to compare and validate against ANN for predicting processing time, ensuring the robustness and reliability of the ML-based framework. All four models showed successful performance with R<sup>2</sup> scores above 0.90, MSE below 1, and MAPE below 10, except 10.26 in Random Forest and 11.15 in Gradient Boosting. However, ANN showed significantly higher accuracy than other traditional regression models comparing MAPE of 1.63 to 10.26 in ANN and Random Forest respectively demonstrating its better performance in analyzing intricate relationships of input features and outputs.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":"83 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976560","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Vaniele Bento dos Santos, Duarte Miranda Neiva, Maria Fernanda Vieira Rocha, João Filipi Rodrigues Guimarães, Leonardo Sarno Soares Oliveira, Fernando José Borges Gomes, Jorge Gominho, Graziela Baptista Vidaurre
{"title":"Effect of the P-factor on the prehydrolysis process of eucalyptus wood for dissolving pulp production","authors":"Vaniele Bento dos Santos, Duarte Miranda Neiva, Maria Fernanda Vieira Rocha, João Filipi Rodrigues Guimarães, Leonardo Sarno Soares Oliveira, Fernando José Borges Gomes, Jorge Gominho, Graziela Baptista Vidaurre","doi":"10.1007/s00107-024-02173-0","DOIUrl":"10.1007/s00107-024-02173-0","url":null,"abstract":"<div><p>Prehydrolysis kraft is the industrial process most frequently used to produce dissolving pulp using continuous or batch technologies. Wood prehydrolysis is the most critical step in the dissolving pulp production stages, aiming at removing hemicelluloses before wood pulping, as hemicelluloses tend to impair cellulose reactivity during the dissolving pulp derivatization process. The performance and extent of this process can be controlled mainly through retention time and temperature conditions, with the P-factor being the severity parameter used to correlate both variables in pulp mills. This study assesses the effects of the P-factor on the prehydrolysis process of eucalyptus clone wood used for dissolving pulp production, deriving regression models to aid in the decision-making and optimization of this process. Five trees from two clones—<i>Eucalyptus urophylla</i> and <i>E. urophylla</i> × <i>E</i>. spp. at the ages of 3 and 5 years—grown in plantations located in Bahia State, Brazil, were evaluated. Hydrothermal pretreatments were applied to wood chips under different time and temperature conditions (P-factor), and the chemical characteristics of the treated wood (lignins and carbohydrates) were determined. The experimental design provided a comprehensive view of the severity factor's effect on each wood macro-component, showing the threshold at which the required amount of hemicelluloses was removed without affecting the cellulose fraction. Hemicelluloses solubilization and removal extended up to 90% within the experimental conditions, with the optimized point achieved at a P-factor of 873. The regression models produced showed good fit for process yield, hemicellulose, and lignin removal.</p></div>","PeriodicalId":550,"journal":{"name":"European Journal of Wood and Wood Products","volume":"83 1","pages":""},"PeriodicalIF":2.4,"publicationDate":"2025-01-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142976507","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"农林科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}