Journal of Advanced Joining Processes最新文献

{"title":"Deep learning-driven active sheet positioning using linear actuators in laser beam butt welding of thin steel sheets","authors":"Dominik Walther ,&nbsp;Leander Schmidt ,&nbsp;Timo Räth ,&nbsp;Klaus Schricker ,&nbsp;Jean Pierre Bergmann ,&nbsp;Kai-Uwe Sattler ,&nbsp;Patrick Mäder","doi":"10.1016/j.jajp.2025.100303","DOIUrl":"10.1016/j.jajp.2025.100303","url":null,"abstract":"<div><div>Welding thin steel sheets in industrial applications is difficult because joint gaps occur during the process, which can lead to weld interruptions. Such welds are considered a reject and in order to avoid the weld to interrupt it is crucial to hinder the formation of joint gaps. Especially laser beam welding is affected by the emergence of gaps. Due to the narrow laser spot, product quality is highly dependent on the alignment and positioning of the sheets. This is typically done by clamping devices, which hold the workpieces in place. However, these clamps are suited for a specific workpiece geometry and require manual redesign every time the process changes. Adaptive clamping devices instead are designed to realize a time-dependent workpiece adjustment. Modeling the joint gap behavior to realize a controller for adaptive clamps can be difficult as the influence of heating, melting, and cooling on the joint gap formation is unknown and varies due to temperature dependent physical properties. Instead, the control parameters and actions can be derived using data-driven methods. In this paper, we present a novel data-driven approach how deep learning can be utilized to manipulate the sheet position during the weld with two actuators that apply force. A temporal convolution neural network (TCN) analyzes the change of the joint gap and predicts the required force to adapt the workpiece position. The developed method has been integrated into the welding process and improves the length of the average weld seam by 39.5% compared to welds without an active adjustment and 1.4% to welds that have been adapted with a constant force.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100303"},"PeriodicalIF":3.8,"publicationDate":"2025-04-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143879131","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Enhancing microhardness and tensile strength of in-process cooled Al-7075-T651 FSAM laminates without compromising ductility through PWHT","authors":"Adeel Hassan ,&nbsp;Khurram Altaf ,&nbsp;Naveed Ahmed ,&nbsp;Srinivasa Rao Pedapati ,&nbsp;Roshan Vijay Marode","doi":"10.1016/j.jajp.2025.100304","DOIUrl":"10.1016/j.jajp.2025.100304","url":null,"abstract":"<div><div>Friction Stir Additive Manufacturing (FSAM) is a promising technique for developing large, irregularly shaped components from non-fusionable aluminum alloys, such as Al-7075, while avoiding solidification defects. Studies on melting-based AM of Al-7075 have shown poor mechanical properties, whereas FSAM has demonstrated comparatively better mechanical properties, though with non-homogeneous properties. Furthermore, conventional post-welding heat treatment (PWHT) has been found to enhance microhardness and strength but significantly reduces ductility. This study addresses these challenges by employing in-process cooling FSAM and cyclic solution PWHT. Seven-layered Al-7075-T651 laminates were manufactured through FSAM, achieving a homogeneous microstructure and mechanical properties using the in-process cooling approach. The cyclic solution treatment resulted in a 38.3 % increase in hardness and a 17.17 % improvement in UTS compared to the as-welded state, without compromising ductility.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100304"},"PeriodicalIF":3.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143847487","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Advances in induction brazing of copper and dissimilar metals: Challenges and emerging trends","authors":"Eyuel A. Lemma ,&nbsp;João M.S. Dias ,&nbsp;António A. Bastos ,&nbsp;Bernardo Mascate ,&nbsp;Ana Horovistiz","doi":"10.1016/j.jajp.2025.100302","DOIUrl":"10.1016/j.jajp.2025.100302","url":null,"abstract":"<div><div>Induction brazing is emerging as a promising technique in current manufacturing processes, particularly noted for its effectiveness in the precise control of heat input, localized heating and rapid processing time. This joining technique is advantageous in industries such as heat pump and refrigeration manufacturing, which require precise and effective joining techniques, particularly for brazing copper and dissimilar metal pipes. Additionally, this technique is environmentally friendly, energy-efficient, cost-effective, and well-suited for automation.</div><div>However, studies have shown that induction brazing of copper and dissimilar metals presents several significant challenges, including thermal distortion-induced cracks due to unoptimized heat input and porosity defects stemming from inadequate filler metal penetration and suboptimal gap size between the joint, these issues can compromise joint integrity, as well as system durability and sustainability. Furthermore, the incompatible thermophysical properties of dissimilar materials and interconnectors pose substantial difficulties in achieving complete metallurgical bonding. The formation of undesirable microstructures, such as hard and brittle intermetallic compounds (IMCs), can further affect the structural, mechanical, and thermal properties of brazed joints.</div><div>This review systematically examines the effects of the most significant induction brazing process parameters on joint performance. Specifically, the effects of heat input, geometrical gap size between the joints, and composition of the filler material on the quality of brazed joints are discussed. Moreover, this review explores the induction brazing of copper with dissimilar metals, including copper with aluminum and copper with stainless steel. The impact of key process parameters on the joint quality of these materials was analyzed. Additionally, opportunities, challenges, and strategies to mitigate the challenges in induction brazing of copper and dissimilar metals are presented induction brazing are presented along with future research directions.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100302"},"PeriodicalIF":3.8,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143807123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct bonding mechanism of titanium and PET resin via heating and pressurization: Influence of bubble dynamics on bonding strength","authors":"Katsuyoshi Kondoh ,&nbsp;Nodoka Nishimura ,&nbsp;Kazuki Shitara ,&nbsp;Shota Kariya ,&nbsp;Ke Chen ,&nbsp;Junko Umeda","doi":"10.1016/j.jajp.2025.100301","DOIUrl":"10.1016/j.jajp.2025.100301","url":null,"abstract":"<div><div>In response to growing environmental concerns, the transportation industry, including automotive and aerospace sectors, has emphasized improving fuel efficiency and reducing carbon dioxide emissions. To achieve significant weight reduction, multi-material design strategies that strategically utilize different materials based on their properties are being adopted. This trend highlights the need for advanced joining technologies capable of bonding dissimilar materials, such as metals and polymers or resins, while maintaining structural integrity and lightweight performance. This study investigates the direct bonding mechanism between pure titanium (Ti) and polyethylene terephthalate (PET) resin using a simple heating and pressurization process. Bubble formation at the bonding interface, a critical factor influencing joint strength, was analyzed through in-situ observation. Results show that controlled bubble dynamics enhance bonding by creating localized pressure, while excessive bubbles act as defects. Optimal bonding conditions were identified at 200–300 °C with relatively high bonding shear stress. X-ray photoelectron spectroscopy revealed the formation of Ti-C bonds, confirming strong chemical interactions at the interface. Additionally, pyrolysis gas chromatography-mass spectrometry identified ethylene glycol as a key component in bubble generation during thermal decomposition of PET. The findings highlight the significance of surface preparation, thermal control, and bubble management in achieving high bonding strength. This research provides insights into sustainable and efficient methods of dissimilar materials that can improve recyclability and support the development of advanced lightweight structures.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100301"},"PeriodicalIF":3.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738514","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Fatigue crack growth and residual stress in simultaneous double-sided friction stir welded aluminum alloy AA6061-T6","authors":"Hendrato ,&nbsp;Muizuddin Azka ,&nbsp;M.Refai Muslih ,&nbsp;Rifky Apriansyah ,&nbsp;Nidya Jullanar Salman ,&nbsp;Sulardjaka ,&nbsp;Ilhamdi ,&nbsp;Jos Istiyanto ,&nbsp;Guino Verma ,&nbsp;Andik Dwi Kurniawan ,&nbsp;Irfan Ansori ,&nbsp;Lukman Shalahuddin ,&nbsp;Jean Mario Valentino ,&nbsp;Yohanes Pringeten Dilianto Sembiring Depari ,&nbsp;Triyono","doi":"10.1016/j.jajp.2025.100300","DOIUrl":"10.1016/j.jajp.2025.100300","url":null,"abstract":"<div><div>Friction stir welding has demonstrated significant efficacy as a solid-state welding methodology for aluminum alloys, including AA6061-T6, and is extensively utilized within automotive and aerospace engineering domains. Nonetheless, conventional FSW methods often lead to uneven residual stress distributions, compromising the material's resistance to fatigue cracking. Simultaneous Double-sided Friction Stir Welding (SDFSW) was introduced to overcome this limitation, offering enhanced welding quality by welding from both sides. This study examines the influence of tool rotational velocity on the fatigue crack growth and the distribution of residual stresses in the SDFSW process applied to AA6061-T6 aluminum. Several rotational velocity combinations were employed to assess their effect on joint quality, encompassing residual stress distribution and cyclic load performance. Based on previous experiments, the SDFSW process uses upper and lower tool speeds. These are 965/965 rpm, 967/1251 rpm and 965/1555 rpm. Fatigue crack growth testing complied with ASTM E647 standards, and the residual stress distribution was assessed through the X-ray diffraction cos α method. Additional mechanical property assessments were performed, including radiographic analysis, examination of the macrostructure and microstructure, microhardness testing, evaluation of tensile strength, and fracture characterization. The findings reveal that the rotational velocity of the tool significantly impacts the weld zone's microstructure, influencing mechanical properties, residual stress distribution, and crack growth behaviors. Among the tested conditions, the tool's rotational speed of 965/1555 rpm yielded the highest tensile strength of approximately 179.82 MPa, representing about 53 % of the strength of the base material and the greatest microhardness of 85 HV. This velocity combination also demonstrated a low fatigue crack growth rate, with Paris law coefficients C and n measured at 2E-08 and 3.6931, respectively, along with a more favorable residual stress distribution.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100300"},"PeriodicalIF":3.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738513","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Application of stress-state-dependent ductile damage and failure model to clinch joining for a wide range of tool and material combinations","authors":"Johannes Friedlein ,&nbsp;Stephan Lüder ,&nbsp;Jan Kalich ,&nbsp;Hans Christian Schmale ,&nbsp;Max Böhnke ,&nbsp;Malte Schlichter ,&nbsp;Mathias Bobbert ,&nbsp;Gerson Meschut ,&nbsp;Paul Steinmann ,&nbsp;Julia Mergheim","doi":"10.1016/j.jajp.2025.100299","DOIUrl":"10.1016/j.jajp.2025.100299","url":null,"abstract":"<div><div>The clinch joining process is simulated for 22 different tool- and material-combinations, using a modular axisymmetric finite element simulation model. Two ductile metals are considered for the sheets, namely the dual-phase steel HCT590X and the aluminium alloy EN AW-6014 T4. A finite elasto-plastic material model is utilised to capture the inherent large plastic strains. Moreover, it is coupled to stress-state-dependent ductile damage and failure to successfully predict possible fracture during the clinch joining process. For all 22 clinch combinations a good agreement is obtained between simulations and experiments, regarding the geometry of the clinch joint, the process force and the occurrence of material failure. This represents a significant advance in the development and comprehension of a versatile process chain resulting from joint research efforts. The validated process simulations are then applied to study the influence of the tool geometries, sheet pre-stretch, and friction. Failure is herein always observed by neck fracture. Nevertheless, detailed analyses of the stress state evolution during the joining process for various locations reveal that the material is exposed to distinctly non-proportional loading paths demanding suitable stress-state-dependent evolution laws. Moreover, even for valid joints, process-induced damage is distributed throughout the joint. Incorporating the damage-induced softening causes an accelerated failure evolution, but has less influence on the global behaviour.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100299"},"PeriodicalIF":3.8,"publicationDate":"2025-03-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143738337","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hot corrosion mechanism in transient liquid phase bonded HX superalloy: Effect of bonding time","authors":"H. Bakhtiari ,&nbsp;M. Farvizi ,&nbsp;M.R. Rahimipour ,&nbsp;A. Malekan","doi":"10.1016/j.jajp.2025.100298","DOIUrl":"10.1016/j.jajp.2025.100298","url":null,"abstract":"<div><div>This study investigates the hot corrosion behavior of transient liquid phase (TLP) bonding in Hastelloy X (HX) subjected to a molten salt environment of Na₂SO₄–V₂O₅ at 900°C, examining various bonding times of 5, 20, 80, 320, and 640 minutes. The samples were bonded at 1070°C, and their corrosion products along with microstructural features were examined. The microstructural analysis confirmed the presence of primary eutectic phases in the joints, including Ni-rich borides and silicides, Ni-Si eutectics, and several chromium-rich borides. Samples bonded for 20 and 80 min showed inferior hot corrosion resistance. Conversely, the sample that was bonded for 320 minutes exhibited improved resistance because of a more uniform distribution of alloy elements and lower boride concentrations at the interface. During the hot corrosion tests, initially, the TLP surface is covered by a dense Cr₂O₃ and NiO layer. After 20 h of hot corrosion, due to the reaction of oxide layers with vanadium, NaVO₃ forms, while sulfur diffusion leads to the evolution of internal sulfides based on Ni, Cr, and Mo. The presence of NaVO₃ and SO₃, along with the reduction of Cr₂O₃, significantly affects the hot corrosion resistance over prolonged exposure.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100298"},"PeriodicalIF":3.8,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143580239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Aluminum surface treatment and process optimization: Boosting mechanical performance in aluminum/polypropylene composite friction stir lap joints","authors":"Mojtaba Movahedi,&nbsp;Mahtab Mohsenirad,&nbsp;Ashkaan Ozlati","doi":"10.1016/j.jajp.2025.100297","DOIUrl":"10.1016/j.jajp.2025.100297","url":null,"abstract":"<div><div>The effects of chemical surface treatment of aluminum sheet and tool rotational speed (in the range of 300–1100 rpm) were studied on the macro/microstructure and mechanical behavior of friction stir lap joints between aluminum-magnesium aluminum alloy and a polypropylene composite containing 20 wt.% talc and 10 wt.% elastomer. Macrostructural studies of the joints revealed the formation of macroscopic mechanical locks between the aluminum and polymer base sheets, characterized by aluminum pieces resembling anchors penetrating the polymer substrate. The size of the anchors decreased as the rotational speed increased, and their orientation changed from being parallel with the interface of the aluminum/composite sheets to being perpendicular, and then facing the opposite direction. The larger anchors, as well as those penetrating relatively perpendicular into the polymer composite substrate, provided the joints with the highest fracture load and absorbed energy up to peak load at the intermediate tool rotational speeds of 700 and 900 rpm. Microstructural analysis demonstrated that chemical surface treatment with a solution of HCl and FeCl₃ in distilled water significantly increased the surface roughness of the aluminum sheet (by a factor of ∼4) and created numerous microscopic voids on its surface. The molten polymer formed during welding penetrated into these voids, creating numerous microscopic mechanical locks. These locks substantially enhanced the tensile-shear performance of the joints, resulting in up to ∼80 % higher fracture load and ∼380 % higher absorbed energy compared to joints without surface treatment of the aluminum. The influence of the morphology of mechanical locks on the location and mode of joint fracture was also investigated.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100297"},"PeriodicalIF":3.8,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143526766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Feasibility study of advanced manufacturing processes: Integrating LPBF and LMD for Inconel 718","authors":"Pinku Yadav ,&nbsp;Olivier Rigo ,&nbsp;Corinne Arvieu ,&nbsp;Eric Lacoste","doi":"10.1016/j.jajp.2025.100296","DOIUrl":"10.1016/j.jajp.2025.100296","url":null,"abstract":"<div><div>Laser hybrid manufacturing combines Laser Powder Bed Fusion (LPBF) and Laser Melt Deposition (LMD) to overcome LPBF's size constraints and LMD's lower geometric precision. This study explores the feasibility of hybrid LPBF-LMD processing for Inconel 718, focusing on interface properties and mechanical performance. Hybrid samples were first fabricated using LPBF, followed by LMD, with LMD process parameters optimized using a second-order parabolic model. Two LPBF variants as-built and solution-annealed were evaluated to assess their influence on interface characteristics. Microstructural analysis revealed a fine-grained LPBF region and a coarser LMD region with distinct texture, both demonstrating defect-free metallurgical bonding. Microhardness measurements showed a gradient at the LPBF interface, increasing from 346 ± 20 HV at the build plate to 410 ± 18 HV, influenced by solidification and thermal gradients. The LMD region exhibited a lower hardness of 314 ± 12 HV, correlating with its coarser microstructure. Tensile tests showed that as-built LPBF-LMD samples had higher elongation (26.76 ± 2 %) compared to solution-annealed samples (8.29 ± 2 %), with the LPBF region contributing more to ductility. These findings provide key insights into optimizing hybrid LPBF-LMD processing for high-performance components, enabling improved repair strategies and multifunctional part design in aerospace, energy, and other critical applications.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100296"},"PeriodicalIF":3.8,"publicationDate":"2025-02-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143464928","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comparative analysis of structural and mechanical properties of duplex stainless steel (DSS) weldments prepared by flux core arc welding and shielded metal arch welding processes","authors":"E. Ajenifuja ,&nbsp;A.P.I. Popoola ,&nbsp;O. Popoola","doi":"10.1016/j.jajp.2025.100295","DOIUrl":"10.1016/j.jajp.2025.100295","url":null,"abstract":"<div><div>Duplex stainless steel (DSS) possesses wide range of useful metallographic and mechanical properties; hence the material has been used in different forms of application namely in chloride present environments such as desalination plants and cooling water services such as conventional and nuclear power stations. However, this material has its limitations as it's susceptible to cracking particularly stress corrosion cracking or pitting corrosion and can exhibit poor metallurgical properties such as microstructures and phase containing unbalanced proportions of ferrite and austenite. In this study, Flux Core Arc Welding (FCAW) is compared with Shielded Metal Arch Welding (SMAW) process, in terms of their effects on the structural and mechanical properties and performances of DSS weldments. Analysis of the microstructure and phases were carried out. Also, the tensile, microhardness, impact and fracture properties were determined with relevant techniques. The results indicated that SMAW and FCAW welding processes differentially influence the structural and mechanical properties of the DSS weldments, consisting of the part of base material, weld and the heat affected zone (HAZ). The weld prepared using the SMAW process exhibited superior hardness characteristics at 309 HV and achieved the highest impact energy absorption of 145.92 <em>J</em>. In contrast, the FCAW prepared weldment exhibited the highest tensile strength, reaching 282.30 kN maximum load.</div></div>","PeriodicalId":34313,"journal":{"name":"Journal of Advanced Joining Processes","volume":"11 ","pages":"Article 100295"},"PeriodicalIF":3.8,"publicationDate":"2025-02-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143453796","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}