Linus Kron, Carolina Marion de Godoy, Merima Hasani, H. Theliander
Abstract The delignification of birch chips during kraft pulping was investigated, targeting both the impregnation and cooking steps. Wood chips were impregnated using white liquor, white liquor + NaCl, water or NaCl aqueous solution. Then, the chips were cooked in batch autoclaves applying the same constant composition cooking conditions for all samples. Pulp and two fractions of black liquor (bulk liquor and centrifuged liquor representing the liquor inside the wood chips and fibers) were collected after different pulping times and analyzed for lignin and carbohydrate content. The dissolved wood components were precipitated from selected samples and characterized with respect to composition, molecular weight distribution and structural motifs. Cooking chemicals in the impregnation liquors led to faster delignification and xylan removal during cooking. Higher contents of lignin and xylan were measured in the lumen than in the bulk. The concentration profiles also showed accumulation of dissolved material in the lumen over time, suggesting significant mass transport limitation from lumen to bulk. Further analysis revealed higher fragmentation/degradation of dissolved material with increasing pulping time and in the bulk when compared to the lumen liquor, as demonstrated by the lower molecular weights and the changes in chemical shifts in the NMR spectra.
{"title":"Kraft cooking of birch wood chips: differences between the dissolved organic material in pore and bulk liquor","authors":"Linus Kron, Carolina Marion de Godoy, Merima Hasani, H. Theliander","doi":"10.1515/hf-2023-0018","DOIUrl":"https://doi.org/10.1515/hf-2023-0018","url":null,"abstract":"Abstract The delignification of birch chips during kraft pulping was investigated, targeting both the impregnation and cooking steps. Wood chips were impregnated using white liquor, white liquor + NaCl, water or NaCl aqueous solution. Then, the chips were cooked in batch autoclaves applying the same constant composition cooking conditions for all samples. Pulp and two fractions of black liquor (bulk liquor and centrifuged liquor representing the liquor inside the wood chips and fibers) were collected after different pulping times and analyzed for lignin and carbohydrate content. The dissolved wood components were precipitated from selected samples and characterized with respect to composition, molecular weight distribution and structural motifs. Cooking chemicals in the impregnation liquors led to faster delignification and xylan removal during cooking. Higher contents of lignin and xylan were measured in the lumen than in the bulk. The concentration profiles also showed accumulation of dissolved material in the lumen over time, suggesting significant mass transport limitation from lumen to bulk. Further analysis revealed higher fragmentation/degradation of dissolved material with increasing pulping time and in the bulk when compared to the lumen liquor, as demonstrated by the lower molecular weights and the changes in chemical shifts in the NMR spectra.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"77 1","pages":"598 - 609"},"PeriodicalIF":2.4,"publicationDate":"2023-07-07","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41355457","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}
I. Nezu, Nuerdong Nueraihaimaiti, Dwi Sukma Rini, F. Ishiguri, Takumi Sato, Keisuke Mitsukuni, Tomohiro Suzuki, N. Habu, J. Ohshima, S. Yokota
Abstract Decay process of wood of Japanese white birch [Betula platyphylla Sukaczev var. japonica (Miq.) H. Hara] tree by Inonotus obliquus (Fr.) Pilát was clarified by using the regression model in wood color and chemical components as a function of height position (1, 2, 3, and 4 m above the ground), wood type (sound wood and decayed wood), and their interactions, and anatomical observations. The 3 m height position, at which a sclerotium of I. obliquus was found, showed the highest decayed area percentage among four height positions. By the results of two-way analysis of variance, wood type affected all color indice. In addition, all factors (height position, wood type, and their interaction) were significant in all wood chemical components except for Klason lignin and hemicellulose. In the wood of the reaction zone, some substances were formed in the lumens of many vessels and a few wood fibers. Based on the results, we proposed the decay process of I. obliquus in naturally grown Japanese white birch, and the proposed process will contribute to a full understanding of the interactions between I. obliquus and Japanese white birch in the future.
{"title":"Clarifying the decay process by Inonotus obliquus in Japanese white birch naturally grown in Nikko, Japan","authors":"I. Nezu, Nuerdong Nueraihaimaiti, Dwi Sukma Rini, F. Ishiguri, Takumi Sato, Keisuke Mitsukuni, Tomohiro Suzuki, N. Habu, J. Ohshima, S. Yokota","doi":"10.1515/hf-2022-0152","DOIUrl":"https://doi.org/10.1515/hf-2022-0152","url":null,"abstract":"Abstract Decay process of wood of Japanese white birch [Betula platyphylla Sukaczev var. japonica (Miq.) H. Hara] tree by Inonotus obliquus (Fr.) Pilát was clarified by using the regression model in wood color and chemical components as a function of height position (1, 2, 3, and 4 m above the ground), wood type (sound wood and decayed wood), and their interactions, and anatomical observations. The 3 m height position, at which a sclerotium of I. obliquus was found, showed the highest decayed area percentage among four height positions. By the results of two-way analysis of variance, wood type affected all color indice. In addition, all factors (height position, wood type, and their interaction) were significant in all wood chemical components except for Klason lignin and hemicellulose. In the wood of the reaction zone, some substances were formed in the lumens of many vessels and a few wood fibers. Based on the results, we proposed the decay process of I. obliquus in naturally grown Japanese white birch, and the proposed process will contribute to a full understanding of the interactions between I. obliquus and Japanese white birch in the future.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"77 1","pages":"585 - 597"},"PeriodicalIF":2.4,"publicationDate":"2023-07-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46403918","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}
Abstract The present study aimed to evaluate the effect of active alkali charge, in kraft cooking of Eucalyptus globulus wood, on the properties of the laboratory-produced tissue paper. Eucalyptus wood chips were cooked under similar conditions at four different active alkali (AA) levels of 16, 19, 21, and 23 % and DEDED sequence was used for subsequent ECF bleaching. Pulps were analyzed for their intrinsic viscosity, chemical composition, and fiber morphology, while the corresponding papers (20 g/m2) were examined for their strength properties, absorptivity, and softness. It was demonstrated that changes in the AA upon cooking, not only affected the chemical composition of the obtained pulps and their intrinsic viscosity, but also the fiber’s shape (e.g., curl and kink). These changes caused variations in the properties of laboratory-produced tissue papers. Thus, the increase in AA led to paper with lower tensile strength, but with better softness. Even though the increase of AA in cooking led to bulkier papers, their absorptivity was not significantly enhanced. This was explained, at least in part, by the lower water retention of the pulps obtained from cooking with higher AA.
{"title":"Effect of alkali charge on the performance of Eucalyptus globulus kraft pulps for tissue applications","authors":"A. Henriques, D. Evtuguin","doi":"10.1515/hf-2023-0006","DOIUrl":"https://doi.org/10.1515/hf-2023-0006","url":null,"abstract":"Abstract The present study aimed to evaluate the effect of active alkali charge, in kraft cooking of Eucalyptus globulus wood, on the properties of the laboratory-produced tissue paper. Eucalyptus wood chips were cooked under similar conditions at four different active alkali (AA) levels of 16, 19, 21, and 23 % and DEDED sequence was used for subsequent ECF bleaching. Pulps were analyzed for their intrinsic viscosity, chemical composition, and fiber morphology, while the corresponding papers (20 g/m2) were examined for their strength properties, absorptivity, and softness. It was demonstrated that changes in the AA upon cooking, not only affected the chemical composition of the obtained pulps and their intrinsic viscosity, but also the fiber’s shape (e.g., curl and kink). These changes caused variations in the properties of laboratory-produced tissue papers. Thus, the increase in AA led to paper with lower tensile strength, but with better softness. Even though the increase of AA in cooking led to bulkier papers, their absorptivity was not significantly enhanced. This was explained, at least in part, by the lower water retention of the pulps obtained from cooking with higher AA.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"77 1","pages":"610 - 617"},"PeriodicalIF":2.4,"publicationDate":"2023-07-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45791548","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}
Evelize Aparecida Amaral, Lívia Freire Baliza, Luana Maria dos Santos, André Tetsuo Shashiki, P. F. Trugilho, P. R. Hein
Abstract The physical properties of wood are important parameters to qualify the material. However, as it is a heterogeneous material, moisture content and wood contractions may vary within the sample. Thus, the objective was to monitor the hydromechanical behavior of wood during drying using near infrared (NIR) spectroscopy and image analysis. Equidistant points were marked on the radial surface of a wooden board and NIR spectra were recorded at each marking during drying of the piece. After spectral acquisition in each drying step, images were obtained and the markings were referenced to monitor contractions during drying. Moisture content (MC) estimates via NIR spectra showed strong correlation with reference values (R2cv = 0.92, RMSEcv = 9.82 %). From the estimates it was possible to generate graphic images to visualize and quantify the spatial variation of MC and shrinkage during wood drying. In the initial stages of drying, the ends of the material showed high moisture in relation to the center of the sample. However, MC loss was 11 % greater at the ends of the wood board when compared to its interior while the shrinkage in external zones was 3 times greater than the internal part. The use of NIR technique associated with image analysis can be a promising tool for estimating moisture contents and contractions in wood.
{"title":"Hydromechanical behavior of wood during drying studied by NIR spectroscopy and image analysis","authors":"Evelize Aparecida Amaral, Lívia Freire Baliza, Luana Maria dos Santos, André Tetsuo Shashiki, P. F. Trugilho, P. R. Hein","doi":"10.1515/hf-2023-0030","DOIUrl":"https://doi.org/10.1515/hf-2023-0030","url":null,"abstract":"Abstract The physical properties of wood are important parameters to qualify the material. However, as it is a heterogeneous material, moisture content and wood contractions may vary within the sample. Thus, the objective was to monitor the hydromechanical behavior of wood during drying using near infrared (NIR) spectroscopy and image analysis. Equidistant points were marked on the radial surface of a wooden board and NIR spectra were recorded at each marking during drying of the piece. After spectral acquisition in each drying step, images were obtained and the markings were referenced to monitor contractions during drying. Moisture content (MC) estimates via NIR spectra showed strong correlation with reference values (R2cv = 0.92, RMSEcv = 9.82 %). From the estimates it was possible to generate graphic images to visualize and quantify the spatial variation of MC and shrinkage during wood drying. In the initial stages of drying, the ends of the material showed high moisture in relation to the center of the sample. However, MC loss was 11 % greater at the ends of the wood board when compared to its interior while the shrinkage in external zones was 3 times greater than the internal part. The use of NIR technique associated with image analysis can be a promising tool for estimating moisture contents and contractions in wood.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"77 1","pages":"618 - 628"},"PeriodicalIF":2.4,"publicationDate":"2023-06-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47970197","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}
J. Bengtsson, Andreas Bengtsson, Hanna Ulmefors, Maria Sedin, Kerstin Jedvert
Abstract Adhesion of fibers within a spun tow, including carbon fibers and precursors, is undesirable as it may interrupt the manufacturing process and entail inferior fiber properties. In this work, softwood kraft lignin was used together with a dissolving pulp to spin carbon fiber precursors. Lignin–cellulose precursors have previously been found to be prone to fiber fusion, both post-spinning and during carbon fiber conversion. In this study, the efficiency of applying different kinds of spin finishes, with respect to rendering separable precursors and carbon fibers, has been investigated. It was found that applying a cationic surfactant, and to a similar extent a nonionic surfactant, resulted in well separated lignin–cellulose precursor tows. Furthermore, the fiber separability after carbon fiber conversion was evaluated, and notably, precursors treated with a silicone-based spin finish generated the most well-separated carbon fibers. The underlying mechanism of fiber fusion post-spinning and converted carbon fibers is discussed.
{"title":"Preventing fiber–fiber adhesion of lignin–cellulose precursors and carbon fibers with spin finish application","authors":"J. Bengtsson, Andreas Bengtsson, Hanna Ulmefors, Maria Sedin, Kerstin Jedvert","doi":"10.1515/hf-2023-0023","DOIUrl":"https://doi.org/10.1515/hf-2023-0023","url":null,"abstract":"Abstract Adhesion of fibers within a spun tow, including carbon fibers and precursors, is undesirable as it may interrupt the manufacturing process and entail inferior fiber properties. In this work, softwood kraft lignin was used together with a dissolving pulp to spin carbon fiber precursors. Lignin–cellulose precursors have previously been found to be prone to fiber fusion, both post-spinning and during carbon fiber conversion. In this study, the efficiency of applying different kinds of spin finishes, with respect to rendering separable precursors and carbon fibers, has been investigated. It was found that applying a cationic surfactant, and to a similar extent a nonionic surfactant, resulted in well separated lignin–cellulose precursor tows. Furthermore, the fiber separability after carbon fiber conversion was evaluated, and notably, precursors treated with a silicone-based spin finish generated the most well-separated carbon fibers. The underlying mechanism of fiber fusion post-spinning and converted carbon fibers is discussed.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"77 1","pages":"648 - 656"},"PeriodicalIF":2.4,"publicationDate":"2023-06-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42513619","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}
Abstract To elucidate the mechanism of wood sandwich compression, the response of wood compressing yield stress to hygrothermal conditions was investigated in this study with respect to preheating temperature (30–210 °C) and moisture content (MC, 0–100 %). An associated functional model was developed to predict wood yield stress based on the measured MC and temperature in wood. A 1 % increase in wood MC or a 10 °C increase of temperature led to a decrease in wood yield stress exceeding 0.1 MPa. Significant variations in yield stress, exceeding 0.8 MPa, were observed between high MC layer(s) and the remaining layer(s) along the wood thickness when there was an MC variation over 5 %. Preheating the wood with by heating platens accelerated water/moisture migration in wood, resulting in relatively low yield stress in the wood interior areas where water/moisture had migrated. This study demonstrated that the comparatively low yield stress of some wood areas was responsible for sandwich compression. When mechanically compressed, only the wood layer(s) with lower yield stress was compressed, leading to sandwich compression, regardless of whether the mechanical force was applied tangentially or radially.
{"title":"Mechanism elucidation for wood sandwich compression from the perspective of yield stress","authors":"Rongfeng Huang, S. Feng, Zhiqiang Gao, H. Liu","doi":"10.1515/hf-2023-0002","DOIUrl":"https://doi.org/10.1515/hf-2023-0002","url":null,"abstract":"Abstract To elucidate the mechanism of wood sandwich compression, the response of wood compressing yield stress to hygrothermal conditions was investigated in this study with respect to preheating temperature (30–210 °C) and moisture content (MC, 0–100 %). An associated functional model was developed to predict wood yield stress based on the measured MC and temperature in wood. A 1 % increase in wood MC or a 10 °C increase of temperature led to a decrease in wood yield stress exceeding 0.1 MPa. Significant variations in yield stress, exceeding 0.8 MPa, were observed between high MC layer(s) and the remaining layer(s) along the wood thickness when there was an MC variation over 5 %. Preheating the wood with by heating platens accelerated water/moisture migration in wood, resulting in relatively low yield stress in the wood interior areas where water/moisture had migrated. This study demonstrated that the comparatively low yield stress of some wood areas was responsible for sandwich compression. When mechanically compressed, only the wood layer(s) with lower yield stress was compressed, leading to sandwich compression, regardless of whether the mechanical force was applied tangentially or radially.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"77 1","pages":"629 - 639"},"PeriodicalIF":2.4,"publicationDate":"2023-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47581842","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}
M. Vaziri, Christopher H. Dreimol, Lars Abrahamsson, P. Niemz, D. Sandberg
Abstract The single exponential kinetics (SEK) and parallel exponential kinetics (PEK) models were fitted to kinetic sorption data of welded and unwelded Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.). Furthermore, diffusion coefficients of water vapour in wood were determined using two different Fickian diffusion solutions. The objective was to identify how well these models could represent the moisture contents of the specimens and to characterize differences between the sorption behaviour of welded and unwelded wood. This knowledge can be used to enhance the moisture resistance of welded wood, develop drying schedules, and improve the quality of timbers. The PEK and SEK models provided the most precise and the second most precise fits to the sorption kinetic data, respectively. The two Fickian models are equivalent when both the infinite series are truncated at n = 10 $n=10$ . The Fickian models also exhibited the highest discrepancy with the experimental data. Nevertheless, the Fickian models fit relatively better to the sorption data of the welded wood than to that of the unwelded wood. This behaviour may be due to the rigid and less-swelling structure of the welded bond line.
{"title":"Parameter estimation and model selection for water vapour sorption of welded bond-line of European beech and Scots pine","authors":"M. Vaziri, Christopher H. Dreimol, Lars Abrahamsson, P. Niemz, D. Sandberg","doi":"10.1515/hf-2022-0013","DOIUrl":"https://doi.org/10.1515/hf-2022-0013","url":null,"abstract":"Abstract The single exponential kinetics (SEK) and parallel exponential kinetics (PEK) models were fitted to kinetic sorption data of welded and unwelded Scots pine (Pinus sylvestris L.) and European beech (Fagus sylvatica L.). Furthermore, diffusion coefficients of water vapour in wood were determined using two different Fickian diffusion solutions. The objective was to identify how well these models could represent the moisture contents of the specimens and to characterize differences between the sorption behaviour of welded and unwelded wood. This knowledge can be used to enhance the moisture resistance of welded wood, develop drying schedules, and improve the quality of timbers. The PEK and SEK models provided the most precise and the second most precise fits to the sorption kinetic data, respectively. The two Fickian models are equivalent when both the infinite series are truncated at n = 10 $n=10$ . The Fickian models also exhibited the highest discrepancy with the experimental data. Nevertheless, the Fickian models fit relatively better to the sorption data of the welded wood than to that of the unwelded wood. This behaviour may be due to the rigid and less-swelling structure of the welded bond line.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"77 1","pages":"515 - 526"},"PeriodicalIF":2.4,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41767043","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}
Tom Franke, Christina Hinterleitner, A. Maillard, Elena Nedelkoska, T. Volkmer
Abstract A treatment to improve the reaction to fire of wood is the wood mineralization. Besides the reaction to fire of the mineralized wood, other mechanical and physical properties are less investigated. In this study, beech and oak were treated in a 2-step mineralization process to obtain calcium oxalate mineralized wood. The 2-step mineralization process is carried out by impregnating two salts diluted in water into the wood, consecutively. Two formulations were applied. For Formulation 1, potassium oxalate and calcium acetate and for Formulation 2 potassium oxalate and calcium chloride were used. Aim of the study is to investigate the impact of the treatments and in combination of the moisture on some selected properties of the mineralized wood. These properties are the swelling due to the mineralization treatment, the Brinell hardness and the volatile organic compounds emissions. The 2-step mineralization treatments increased the moisture adsorption of wood. However, the removal of unreacted precursors due to leaching provides a material with comparable moisture dynamics to untreated wood. Swelling, hardness and volatile organic compounds emissions are decreased by the mineralization. However, leaching of the reaction by-products leads to a material with comparable properties to those of untreated wood.
{"title":"The impact of moisture on salt treated and 2-step mineralized wood","authors":"Tom Franke, Christina Hinterleitner, A. Maillard, Elena Nedelkoska, T. Volkmer","doi":"10.1515/hf-2023-0003","DOIUrl":"https://doi.org/10.1515/hf-2023-0003","url":null,"abstract":"Abstract A treatment to improve the reaction to fire of wood is the wood mineralization. Besides the reaction to fire of the mineralized wood, other mechanical and physical properties are less investigated. In this study, beech and oak were treated in a 2-step mineralization process to obtain calcium oxalate mineralized wood. The 2-step mineralization process is carried out by impregnating two salts diluted in water into the wood, consecutively. Two formulations were applied. For Formulation 1, potassium oxalate and calcium acetate and for Formulation 2 potassium oxalate and calcium chloride were used. Aim of the study is to investigate the impact of the treatments and in combination of the moisture on some selected properties of the mineralized wood. These properties are the swelling due to the mineralization treatment, the Brinell hardness and the volatile organic compounds emissions. The 2-step mineralization treatments increased the moisture adsorption of wood. However, the removal of unreacted precursors due to leaching provides a material with comparable moisture dynamics to untreated wood. Swelling, hardness and volatile organic compounds emissions are decreased by the mineralization. However, leaching of the reaction by-products leads to a material with comparable properties to those of untreated wood.","PeriodicalId":13083,"journal":{"name":"Holzforschung","volume":"77 1","pages":"541 - 553"},"PeriodicalIF":2.4,"publicationDate":"2023-06-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"41353638","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}
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