Acta Materialia最新文献

{"title":"Mechanisms determining bendability in Al-Mg-Si-Fe crossover alloys","authors":"Bernhard Trink ,&nbsp;Irmgard Weißensteiner ,&nbsp;Peter J. Uggowitzer ,&nbsp;Sebastian Samberger ,&nbsp;Diego S.R. Coradini ,&nbsp;Georg Falkinger ,&nbsp;Katharina Strobel ,&nbsp;Stefan Pogatscher","doi":"10.1016/j.actamat.2025.120810","DOIUrl":"10.1016/j.actamat.2025.120810","url":null,"abstract":"<div><div>Al-Mg-Si-Fe crossover alloys combine the microstructure-controlling effect of iron-rich intermetallic primary phases with the age-hardening properties of Al-Mg-Si alloys. This study investigates the mechanisms which determine bendability in these alloys. The commercial alloy 6016 was heavily doped with Fe and Si to conceptionally mimic some of the effects of increased end-of-life scrap input. The Si content was adjusted to compensate for the Si trapped in iron-rich phases. Various processing routes, from casting to cold-rolled sheet metal, were also considered. The study concluded that the bendability of Al-Mg-Si-Fe crossover alloys does not correlate strictly with the addition of Fe, but is effected mainly by the composition of the aluminum matrix and the processing conditions. The investigation provides detailed insights into the effects of the type and density of intermetallic particles, the overall strength of the alloy, its strain hardening and the development of porosity due to particle cracking and the dissolution of phases leading to Kirkendall pores. It shows that bending is limited by damage and further void formation near the surface. It links the fracture of iron-rich primary phases which degrade bending performance itself to aluminum matrix strength and strain hardening. It also reveals that Kirkendall pores have a strong negative effect on bending because (similarly to fractured primary phase particles) these pores promote the formation of narrow shear bands which cause early bending failure. Finally, the study demonstrates that pore formation itself is triggered by slow cooling steps during manufacturing, but that the pores can be healed by adjusting the solution treatment time to restore bending capacity in all the alloys and conditions investigated.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"287 ","pages":"Article 120810"},"PeriodicalIF":8.3,"publicationDate":"2025-02-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143192129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of vacancy wind effect or cross phenomenological constants of Onsager formalism considering actual (ideal or non-ideal) molar volume variation on diffusing elements in binary solid solutions","authors":"Aloke Paul","doi":"10.1016/j.actamat.2025.120807","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120807","url":null,"abstract":"Manning (1967-70) established the intrinsic and tracer diffusion coefficient correlation by considering both main and cross-phenomenological constants of Onsager formalism, albeit assuming constant molar volume, simplifying the analysis. He mentioned the need for correction when molar volume variation is not constant, although it has never been practiced until now. The variation in molar volume with composition in real systems is never exactly constant. This may vary (almost) ideally following the rule of mixture (Vegard's law) or deviate positively and negatively. Therefore, the correct correlation considering the actual molar volume in a real system is first derived in this study. The differences in the contribution of the vacancy wind effect (role of cross phenomenological constants of Onsager) considering actual and constant molar volume variation (which was practiced previously) are calculated and explained. This shows that the contribution was underestimated or overestimated by considering a constant molar volume variation and depending on whether the element with higher or lower partial molar volume has higher or lower relative mobility. The tracer diffusion coefficient calculated in different systems from intrinsic diffusion coefficients estimated following the Kirkendall marker experiment explains the importance of considering the ideal or non-ideal molar volume instead of the constant molar volume variation. Therefore, this study addresses a critical issue faced during the last several decades by calculating inaccurate values of the vacancy wind effect and the tracer diffusion coefficients from the diffusion couple experiments considering constant molar volume variation.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"28 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-02-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143124521","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Quantum Electronic Strengthening of Covalent Semiconductor Materials by Excess Electron/Hole Doping","authors":"Hiroki Noda, Shumpei Sakaguchi, Ryoga Fujita, Susumu Minami, Hiroyuki Hirakata, Takahiro Shimada","doi":"10.1016/j.actamat.2025.120795","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120795","url":null,"abstract":"Covalent semiconductor materials are indispensable for the development of modern society because of their excellent semiconductor properties, but they are consistently challenged by failures due to brittle fracture. Recently, both experimental and theoretical attempts to modify the strength of materials by electron doping have been reported. Here, we comprehensively examine the impact of excess electrons and holes on the bonding strength of a typical covalent material based on first-principles calculations. The bond strength is reduced or increased monotonically and linearly with electron doping density, resulting in an approximate 60% variation at the highest feasible doping density. The degree of strength change per carrier density for each material is found to correlate with its bonding characteristics, with stronger ionic bonding properties exhibiting larger changes. Furthermore, the quantum mechanism of the change in strength is explained by energetic contribution of bonding orbitals occupied by introduced charge. These results indicate that covalent semiconductor materials share a common mechanism of strengthening by electron doping, which could contribute to the design of more robust semiconductor products.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"10 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-02-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143077285","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The mechanism for the enhanced piezoelectricity, dielectric property and thermal stability in (K,Na)NbO3 ceramics","authors":"Shangren Zeng ,&nbsp;Jinzhu Zou ,&nbsp;Miao Song ,&nbsp;Shengwen Liu ,&nbsp;Jianxun Zhang ,&nbsp;Tongxin Wei ,&nbsp;Qiwei Sun ,&nbsp;Yan Zhang ,&nbsp;Xi Yuan ,&nbsp;Dou Zhang","doi":"10.1016/j.actamat.2025.120801","DOIUrl":"10.1016/j.actamat.2025.120801","url":null,"abstract":"<div><div>In the context of piezoelectric applications, it is essential not only to achieve a high piezoelectric coefficient but also to ensure excellent overall performance, which includes appropriate dielectric property and superior thermal stability. Despite two decades of research, (<em>K,Na</em>)<em>NbO</em>₃ (KNN) ceramics have been recognized as a lead-free ferroelectric material capable of replacing PZT ceramics, the relationships between structure, piezoelectricity, dielectric property, and thermal stability remain incompletely understood. Here, taking piezoelectric energy harvester (PEH) as an example, we combined property measurements and atom-scale scanning transmission electron microscopy (STEM) and phase-field simulations to establish the structure-property relationship in lead-free KNN ceramic. The results indicate that the energy harvesting performance of KNN reaches its peak when polarization configuration achieves a balance between the enhancement of piezoelectric coefficient and dielectric permittivity. Large angle polarization at the scale of ∼5–10unit cells embedded within the long-range order T phase can lead to high piezoelectric coefficient, moderate dielectric permittivity, superior temperature stability, and excellent energy harvesting performance. This work elucidates the relationship between structure and properties in KNN piezoceramic and provides guidance for the design of high-performance ferroelectric ceramic for PEH, which is expected to benefit the design of lead-free piezoceramics for other piezoelectric applications.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"287 ","pages":"Article 120801"},"PeriodicalIF":8.3,"publicationDate":"2025-02-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hierarchy of defects in near-Σ5 tilt grain boundaries in copper studied by length-scale bridging electron microscopy","authors":"Hui Ding ,&nbsp;Anoosheh Akbari ,&nbsp;Enze Chen ,&nbsp;Harald Rösner ,&nbsp;Timofey Frolov ,&nbsp;Sergiy Divinski ,&nbsp;Gerhard Wilde ,&nbsp;Christian H. Liebscher","doi":"10.1016/j.actamat.2025.120778","DOIUrl":"10.1016/j.actamat.2025.120778","url":null,"abstract":"<div><div>Grain boundaries (GBs) are material imperfections that significantly impact material properties. Understanding how their atomic structure deviates from ideal symmetric orientations is crucial for establishing fundamental structure–property relationships. In this study, we utilized aberration-corrected scanning transmission electron microscopy, geometric phase analysis and nanobeam electron diffraction (NBED) to examine the structure of a series of near-<span><math><mrow><mi>Σ</mi><mn>5</mn><mrow><mo>(</mo><mn>310</mn><mo>)</mo></mrow><mrow><mo>[</mo><mn>001</mn><mo>]</mo></mrow></mrow></math></span> tilt grain boundaries in copper and to explore the formation of GB defects and their associated strain field evolution on different length scales. Globally, the GB appears flat with no noticeable defects, as confirmed by NBED strain mapping. On the atomic-scale, however, various types of GB defects are observed. When a slight deviation in the misorientation is introduced, a patterning emerges featuring characteristic structural units from the <span><math><mrow><mi>Σ</mi><mn>5</mn><mrow><mo>(</mo><mn>310</mn><mo>)</mo></mrow><mrow><mo>[</mo><mn>001</mn><mo>]</mo></mrow></mrow></math></span> and <span><math><mrow><mi>Σ</mi><mn>5</mn><mrow><mo>(</mo><mn>210</mn><mo>)</mo></mrow><mrow><mo>[</mo><mn>001</mn><mo>]</mo></mrow></mrow></math></span> tilt boundaries. This pattern can be interpreted as secondary GB dislocations, a conclusion that is supported by GB structure prediction. Since these defects are confined to within the GB core, their associated strain field does not extend into the adjacent bulk grains. The structural landscape of the GB becomes more complex when GB plane inclination is also present, such as a wavy morphology or staircase-like architecture. The wavy morphology shows an unusual V-shape of the expansion and compression zones of the GB facet junctions that continue to extend into the bulk crystals for several nanometers. Our investigation into GB structure, particularly its inherent defects, is a prerequisite towards gaining atomic-scale insights into their potential impact on material properties.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"287 ","pages":"Article 120778"},"PeriodicalIF":8.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072547","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elastic and failure characterization of hydroxyapatite TPMS scaffolds using a combined approach of ultrasound, compression tests and micro-CT based numerical models","authors":"Luca D’Andrea ,&nbsp;Roberta Gabrieli ,&nbsp;Lorenzo Milano ,&nbsp;Luca Magagnin ,&nbsp;Anna De Cet ,&nbsp;Dario Alidoost ,&nbsp;Martin Schwentenwein ,&nbsp;Enrica Verné ,&nbsp;Francesco Baino ,&nbsp;Pasquale Vena","doi":"10.1016/j.actamat.2025.120776","DOIUrl":"10.1016/j.actamat.2025.120776","url":null,"abstract":"<div><div>Hydroxyapatite is a widely used ceramic material for bone tissue engineering. For creating suitable scaffolds, reliable design and thorough characterization are essential. In this study, we designed and 3D printed three Triply Periodic Minimal Surface (TPMS) scaffold geometries using Vat Photopolymerization (VPP). We employed a combined experimental and numerical analysis approach to evaluate printing accuracy and its correlation with the mechanical properties of the scaffolds. Our findings indicate that VPP can print complex micro-architectures as those of the TPMS with thin wall thickness in the range of few hundreds of micrometers. Ultrasound waves and compression tests were conducted to determine the effective stiffness and strength of scaffolds, respectively. Finite Element Models were developed based on Computed micro-Tomography acquisitions to simulate the experimental compression tests, showing strong alignment with the experimental data. Among the tested TPMS geometries, the Diamond microstructures fail with the lowest specific strength, while the highest specific strength is shown by the I-graph and wrapped package-graph (IWP) scaffolds.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"287 ","pages":"Article 120776"},"PeriodicalIF":8.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072234","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"On the influence of temperature on the 1/2<110> screw dislocation core in uranium dioxide","authors":"Jules-Elémir Suchorski ,&nbsp;Adrien Pivano ,&nbsp;Jonathan Amodeo","doi":"10.1016/j.actamat.2025.120771","DOIUrl":"10.1016/j.actamat.2025.120771","url":null,"abstract":"<div><div>Understanding the fundamental processes of plastic deformation in uranium dioxide (main nuclear fuel) is critical to predict the structural integrity of nuclear reactors under off-normal operating conditions. While the 1/2<span><math><mrow><mo>&lt;</mo><mn>110</mn><mo>&gt;</mo></mrow></math></span>{001} edge dislocation has been extensively studied in recent years due to its role as rate-limiting character for plastic deformation in the primary slip systems, much less is known about the screw dislocation, despite its recently shown involvement in the composite slip process at high temperature. Here, molecular simulations are employed to investigate the evolution of the 1/2<span><math><mrow><mo>&lt;</mo><mn>110</mn><mo>&gt;</mo></mrow></math></span> screw dislocation core structure in UO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> with temperature. First, a comparison of the various interatomic models tested at 0 K addresses the stability of a <em>zig-zag</em> core structure predominantly spread in {001}. Then, molecular dynamics simulations confirm the stability of the screw dislocation core spread in {001} up to 1600 K, after which a transition towards more complex core structures involving the {110} and {111} planes is characterized, with direct implications on the shear-ability of the various crystallographic planes of the fluorite structure. Further analysis reveal that the transition of the screw dislocation core, that favors thermal fluctuation of the dislocation core in {111} slip planes at high temperature, is driven by the local disordering of the anionic sublattice within the dislocation core, preceding the well-known Bredig transition in UO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>. This transition of the screw dislocation core is at the roots of the composite slip process, which was recently proposed to explain the Schmid law breakdown observed in UO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> single crystal.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"287 ","pages":"Article 120771"},"PeriodicalIF":8.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072107","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Interfacial strain concentration and relaxation along crystalline-amorphous boundaries of B2-reinforced bulk-metallic-glass-composites during loading","authors":"Xiaoling Fu ,&nbsp;Jiaqing Wu ,&nbsp;Zhi Zhou ,&nbsp;Ming Jen Tan ,&nbsp;Yongjiang Huang ,&nbsp;Jianfei Sun ,&nbsp;Wenli Song ,&nbsp;Pengfei Guan ,&nbsp;Yuanzheng Yang ,&nbsp;Yi Li ,&nbsp;Robert O. Ritchie","doi":"10.1016/j.actamat.2025.120787","DOIUrl":"10.1016/j.actamat.2025.120787","url":null,"abstract":"<div><div>Interfacial stress concentration promotes both martensitic transformation nucleation and shear band initiation in B2-reinforced bulk-metallic-glass-composites. As the martensitic transformation occurs in the crystalline (soft) regime, shear bands are often observed in the amorphous (hard) matrix. A long-standing question has been when the stress concentration will prompt the martensitic transformation and when it will give rise to shear band initiation. By definition, stress concentration results from the regional Young's modulus multiplied by the local strain concentration. The localized strain concentration along crystalline-amorphous boundary plays decisive roles in promoting phase transformation and localized shear events. By constantly tracking the interfacial strain distribution through Molecular Dynamics methods, the location and magnitude of the interfacial strain concentration and its relaxation are quantified and correlated with the regional modulus differences. We are proposing that the regional strain concentration and relaxation is always located along soft/hard domains during loading so as to maintain the compatibility of interfacial deformation.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"287 ","pages":"Article 120787"},"PeriodicalIF":8.3,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Revisiting the vacancy diffusion behavior under the influence of solute trapping in dilute alloys","authors":"Xuezhou Wang, Chunan Li, Yijiang Xu, Yanjun Li","doi":"10.1016/j.actamat.2025.120788","DOIUrl":"https://doi.org/10.1016/j.actamat.2025.120788","url":null,"abstract":"Vacancies play crucial roles in various phase transformation processes in metallic solids, but their diffusion behaviors in the presence of solute elements are less known. In this work, the impacts of substitutional solute atoms on vacancy diffusion in dilute alloys are quantitatively studied. Using Al-Sn alloy system as an illustrative case, the detailed vacancy diffusion behavior under the influence of Sn atoms is revealed by atomistic kinetic Monte Carlo (KMC) simulations. Accordingly, a physics-based analytic model is derived to quantify the influences of substitutional solute atoms on the vacancy diffusivity in dilute alloys. In the model, the diffusion of vacancy is rigorously treated as a combination of free diffusion within host atoms and co-diffusion together with solute atoms. Based on the vibrational frequency, migration enthalpy and binding energy of solute-vacancy pair obtained from first-principles calculations, the time fraction for a vacancy trapping by solute atoms and the corresponding correlation factor of diffusion are derived. The predicted vacancy diffusivity in the show-case Al-Sn alloys at different temperatures shows a good agreement with the diffusivity data extracted from KMC simulations within the five-frequency model framework. By using the analytical model, the trapping effects of different impurity elements on vacancy diffusion in Al alloys are screened and discussed, which will help to further exploit the influences of different solute atoms on vacancies in solid-state phase transformations in the alloys.","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"60 1","pages":""},"PeriodicalIF":9.4,"publicationDate":"2025-01-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143072014","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Measuring interdiffusion coefficient from XRD spectra of thermally annealed superlattices: A combined modeling and experimental study in Fe–Cr nanometric multilayers","authors":"Thomas Schuler ,&nbsp;Pamela Camilos ,&nbsp;Gladice Magnifouet ,&nbsp;Frédéric Soisson ,&nbsp;Estelle Meslin ,&nbsp;Maxime Vallet ,&nbsp;Véronique Pierron-Bohnes ,&nbsp;Maylise Nastar","doi":"10.1016/j.actamat.2025.120765","DOIUrl":"10.1016/j.actamat.2025.120765","url":null,"abstract":"<div><div>In this paper, we employ atomic kinetic Monte Carlo (AKMC) simulations to get insight into the kinetics of Fe–Cr interdiffusion in nanometric multilayer materials, and the relevant information that can be extracted from the evolution of the experimental X-ray diffraction (XRD) spectrum. For this purpose, we develop an elastic model to obtain the interplanar spacing for a given composition profile derived from AKMC simulation, and then we simulate the corresponding XRD spectrum and compare it with the experimental one. We find a very good agreement between the two, which validates our modeling procedure. Then we put some effort into trying to relate specific features of the XRD spectra with phenomena occurring at the atomic scale, mostly the decay of satellite peak intensities over time. The interdiffusion coefficients extracted from the XRD spectra are underestimated in the Fe-rich phase and overestimated in the Cr-rich phase, but more or less within one order of magnitude of the values obtained from standard measurements. Extracting more quantitative kinetic information directly from the experimental XRD spectra is rather difficult without resorting to a modeling study.</div></div>","PeriodicalId":238,"journal":{"name":"Acta Materialia","volume":"287 ","pages":"Article 120765"},"PeriodicalIF":8.3,"publicationDate":"2025-01-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143056702","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}