Journal of The European Ceramic Society最新文献

{"title":"Thermal erosion test of ZrB2-based ceramics","authors":"Oleg Grigoriev ,&nbsp;Dariia Chernomorets ,&nbsp;Vladimir Vinokurov ,&nbsp;Irina Neshpor ,&nbsp;Gennadii Frolov ,&nbsp;Serhii Teslia ,&nbsp;Dmytro Vedel ,&nbsp;Laura Silvestroni","doi":"10.1016/j.jeurceramsoc.2024.117050","DOIUrl":"10.1016/j.jeurceramsoc.2024.117050","url":null,"abstract":"<div><div>The thermal erosion of a set of bulk fully dense and 10 vol% porous ZrB₂-based ceramics of different composition were machined as sharp wing and tested in an air-fuel mixture flow formed by mixing air and kerosene with an oxygen content ∼5 wt%. The resulting pressure in the combustion chamber was 0.8 MPa and the flow temperature was 1500°C. Microstructural analyses upon the tests evidenced that criteria for material success include high density and high thermal conductivity, along with formation of stable compounds. These results were supported by numerical simulation. Among all tested materials, only ZrB₂ - 15 vol% MoSi₂ (ZM) met all the requirements and successfully survived the thermal erosion test up to 1200 sec.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117050"},"PeriodicalIF":5.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658222","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of Zr4+ doping on the creep behavior of the oxygen transport membrane BaFeO3-d","authors":"Rodrigo Arenas ,&nbsp;Jürgen Malzbender ,&nbsp;Viviana Meruane ,&nbsp;Ali Akbari-Fakhrabadi","doi":"10.1016/j.jeurceramsoc.2024.117051","DOIUrl":"10.1016/j.jeurceramsoc.2024.117051","url":null,"abstract":"<div><div>Aiming towards insight into the stability of newly developed advanced ceramic membrane materials, the time-dependent deformation at elevated temperatures is particularly important, where special consideration should be given to application-relevant atmospheres. This study examines the influence of Zr⁴⁺ doping on the creep behavior of BaFeO_3-δ in air and nitrogen atmospheres at temperatures between 700 ºC and 900°C under compressive stresses ranging from 20 MPa to 60 MPa. BaFeO_3-δ creep investigations revealed a transition from primarily diffusive to a combination of diffusive and dislocation-based mechanisms, owing to increasing oxygen deficiencies with increasing temperatures that culminate in a low to high symmetric crystal structure transition. Zr⁴⁺ doping improved the creep resistance and altered the creep mechanism to a predominantly dislocation-based mechanism, accompanied by a transition to a cubic crystal structure. Nitrogen atmospheres negatively affected the creep resistance of BaFeO_3-δ and BaFe_0.9Zr_0.1O_3-δ, increasing the creep deformation rates for all temperature and stress levels.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117051"},"PeriodicalIF":5.8,"publicationDate":"2024-11-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658275","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"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 mechanical and dielectric properties of high-density Ti-doped MgAl2O4 ceramic prepared by non-hydrolytic sol-gel combined with mechanochemical method","authors":"Kaite Wei ,&nbsp;Yao Tang ,&nbsp;Jian Wang ,&nbsp;Xiao Zhang ,&nbsp;Sen Liang","doi":"10.1016/j.jeurceramsoc.2024.117048","DOIUrl":"10.1016/j.jeurceramsoc.2024.117048","url":null,"abstract":"<div><div>The synthesis of MgAl₂O₄ requires high calcination temperatures which generally result in larger grain sizes and smaller specific surface areas. These factors pose challenges in achieving high-density MgAl₂O₄ ceramic. This study introduces an innovative approach that has successfully sintered MgAl₂O₄ ceramic at 1500 ℃ with MgAl₂O₄ powder prepared using a Non-Hydrolytic Sol-Gel (NHSG) method combined with a mechanochemical method. The sintered MgAl₂O₄ ceramic with 2 wt% TiCl₄ doping displays an apparent porosity of only 0.09 %, a flexural strength of 183 MPa, a relative permittivity of 8.7, a quality factor of 77000 GHz, and a frequency temperature coefficient of −59.4 ppm/℃. The introduction of titanium ions causes lattice distortion and cationic vacancies, which promotes sintering and improves the mechanical and dielectric properties of the resulting ceramic. This study demonstrates the effectiveness of NHSG combined with the mechanochemical method in preparing MgAl₂O₄ ceramic with enhanced sintering properties.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117048"},"PeriodicalIF":5.8,"publicationDate":"2024-11-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658221","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Sintering of lunar regolith simulants using a domestic microwave: A rapid and energy-efficient strategy for construction material fabrication","authors":"Zhen Liu,&nbsp;Jinping Li,&nbsp;Xuan Yang,&nbsp;Yongwen Ding,&nbsp;Songhe Meng","doi":"10.1016/j.jeurceramsoc.2024.117047","DOIUrl":"10.1016/j.jeurceramsoc.2024.117047","url":null,"abstract":"<div><div>Utilization of lunar regolith as building material to construct future lunar bases is receiving increasing attention. The sintering method does not need additional additives, but still has some restrictions. This study presents a rapid and energy-efficient strategy for sintering lunar regolith simulants (i.e., mare (CLRS-1) and highlands (SC-080)), where a domestic microwave and ceramic fiber microwave kiln performed hybrid heating for 11 and 14 minutes, respectively. The corresponding energy consumption is just 69 and 98 MJ/kg, respectively. The low melting point minerals in the simulants melt at high temperatures, causing the grains to bond to each other. The density of sintered samples reached 2.34 and 2.23 g/cm³, respectively. The mechanical and thermal properties of both samples are comparable to those of Earth-based concrete and brick, and show excellent durability in a simulated lunar surface environment, revealing a promising processing route for early lunar surface construction.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117047"},"PeriodicalIF":5.8,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578411","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Crystallization and phase transition boosted optical linear& nonlinear and magnetic properties in transparent xCu: BaSnO3 NCs/glass-ceramic","authors":"Yuandong Xu ,&nbsp;Qiuling Chen ,&nbsp;Chunlong Guan","doi":"10.1016/j.jeurceramsoc.2024.117034","DOIUrl":"10.1016/j.jeurceramsoc.2024.117034","url":null,"abstract":"<div><div>In this study, cubic xCu: BaSnO₃ (x = 0, 1, 3, and 5 mol%) perovskite nanocrystals were synthesized using a hydrothermal method. The influence of Cu doping levels on the crystal structure, morphology, size, and properties was analyzed using X-ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Raman, Ultraviolet-Visible Spectroscopy (UV–vis), Vibrating Sample Magnetometry (VSM), and X-ray Photoelectron Spectroscopy (XPS) techniques. Across the 1–5 % doping range, the cubic BaSnO₃ structure was maintained with Cu²⁺ in CuO₆ replacing Sn⁴⁺ in the B-site. XPS analysis confirmed the formation of oxygen vacancies due to charge imbalance, leading to a decrease in optical bandgap and an increase in ferromagnetic moment. When various contents of xCu: BaSnO₃ were doped into borosilicate glass, significant impacts on the glass network, crystallization, and properties were observed. Nanocrystals (∼50 nm) transitioned from cubic to orthorhombic phase beyond 3 mol% doping, modifying the glass network by converting BO₃ to BO₄, AlO₄ to AlO₆, and CuO₆ to CuO₄. This phase change endowed the glass's strong ferromagnetic moment and absorption due to the t_2 g→e_g transitions of Cu²⁺ in CuO₆, and reduced the optical bandgap from 3.16 to 2.2 eV. The glass also exhibited improved Vickers hardness (475 HV) and a high Verdet constant of 0.174 min/G·cm due to network modifications. Glass also shows a distinct red emission at 596 nm with a 160 µs lifetime and good thermal stability, while doping levels above 3 % resulted in emission quenching. The optical nonlinear absorption coefficient and nonlinear susceptibility increased with higher doping levels, reaching huge values of α₃: 5.12×10⁻¹⁰ m/W and χ⁽³⁾: 7.52×10⁻¹⁰ esu, indicating potential for self-focusing applications. The increased polarizability also resulted in a high dielectric constant (18) and a large P-E loop of glasses which are promising for advanced photonics devices.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117034"},"PeriodicalIF":5.8,"publicationDate":"2024-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142593772","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of lanthanum on the structure, properties and high-temperature oxidation patterns of the (Hf,Ta)B2–SiC ceramics","authors":"A.N. Astapov ,&nbsp;A.Yu. Potanin ,&nbsp;A.A. Zaitsev ,&nbsp;Yu.S. Pogozhev ,&nbsp;N.V. Shvyndina ,&nbsp;A.N. Tarasova ,&nbsp;E.A. Levashov","doi":"10.1016/j.jeurceramsoc.2024.117044","DOIUrl":"10.1016/j.jeurceramsoc.2024.117044","url":null,"abstract":"<div><div>This paper focuses on the kinetics and the mechanism of oxidation (at 1650°C) of the ceramics based on the (Hf_0.8Ta_0.2)B₂, β-SiC and LaF₃ (0 and 3.5 wt%) phases fabricated by a combination of self-propagating high-temperature synthesis (SHS) and hot pressing (HP). The physicomechanical and thermophysical properties of the ceramics were determined. The effect of doping with lanthanum on the kinetics and mechanism of oxidation as well as the structural and morphological features of the resulting oxide layers after efficiency of their protective action was analyzed. The evolutionary changes in the structure were studied: the formation of a three-layered heterogeneous oxide film, modification of borosilicate glass with Hf⁴⁺, Ta⁵⁺ and La³⁺ cations, formation of Hf⁴⁺-doped La_1/3TaO₃ globules followed by their growth via the Ostwald ripening mechanism, generation and oxidation of the secondary TaB₂ phase, significant reduction of the content of the HfSiO₄ phase, etc. Doping the ceramics with lanthanum was shown to exhibit a negative effect on high-temperature oxidation resistance, and the main reasons for that were analyzed.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117044"},"PeriodicalIF":5.8,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142658223","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Significantly enhanced microwave-millimeterwave properties of cordierite ceramics: Roundness regulation of Si-Al hexagonal ring, analysis of far-infrared reflectance and terahertz time-domain spectroscopy","authors":"Lin Cao ,&nbsp;Yuanyuan Wang ,&nbsp;Xueqing Yu ,&nbsp;Zhilun Lu ,&nbsp;Ge Wang ,&nbsp;Minmin Mao ,&nbsp;Bing Liu ,&nbsp;Lei Cao ,&nbsp;Hadi Barzegar Bafrooei ,&nbsp;Matjaz Spreitzer ,&nbsp;Dawei Wang ,&nbsp;Kaixin Song","doi":"10.1016/j.jeurceramsoc.2024.117045","DOIUrl":"10.1016/j.jeurceramsoc.2024.117045","url":null,"abstract":"<div><div>Ultra-low permittivity (<em>ε</em>_<em>r</em>：4–5) Mg₂Al_{4–<em>x</em>}(Ge_0.5Mg_0.5)_<em>x</em>Si₅O₁₈ (0.12 ≤ <em>x</em> ≤ 0.28) and Mg₂Al_{4–<em>y</em>}(Mn_0.5Mg_0.5)_<em>y</em>Si₅O₁₈ (0.1 ≤ <em>y</em> ≤ 0.3) cordierite ceramics were fabricated by solid-state reaction method. The improvement in [(Si₄Al₂)O₁₈] hexahedral ring roundness significantly enhances the quality factor through the substitution of complex ionic pairs of Ge_0.5Mg_0.5/Mn_0.5Mg_0.5 for Al lattice sites in the [(Si₄Al₂)O₁₈] hexahedral ring of these cordierite ceramics. Excellent microwave dielectric performances of Mg₂Al_3.8(Ge_0.5Mg_0.5)_0.2Si₅O₁₈ and Mg₂Al_3.8(Mn_0.5Mg_0.5)_0.2Si₅O₁₈ ceramics sintered at 1400 °C were demonstrated using the Hakki-Coleman resonant method with <em>ε</em>_<em>r</em> = 4.676, <em>Q×f</em> = 186, 503 [email protected] GHz and 199,476 GHz @ 27.434 GHz, <em>τ</em>_<em>f</em> = −20.02 ppm/°C and <em>ε</em>_<em>r</em> = 4.807, <em>Q×f</em> = 101,420 [email protected] GHz and 143,005 GHz @ 27.366 GHz, <em>τ</em>_<em>f</em> = −26.44 ppm/°C, respectively. These results present the potential application of high-quality cordierite in future B5G/6 G millimeter and terahertz communication frequency bands.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117045"},"PeriodicalIF":5.8,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142578409","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Improved hydrostatic piezoelectric property via incorporation of porous PZT ceramics into 1–3 type PZT-polymer composites: Design to fabrication","authors":"Il-Gok Hong,&nbsp;Ho-Yong Shin,&nbsp;Jong-Ho Kim,&nbsp;Jong-In Im","doi":"10.1016/j.jeurceramsoc.2024.117046","DOIUrl":"10.1016/j.jeurceramsoc.2024.117046","url":null,"abstract":"<div><div>PZT ceramic is widely used as sensors, especially in underwater applications like sound navigation and ranging(SONAR), due to its piezoelectric properties. However, single-phase PZT ceramics have poor hydrostatic piezoelectric properties, leading to the development of porous PZT and PZT-polymer composites. This study enhanced the hydrostatic figure of merit(HFOM) value by incorporating porous PZT into a 1–3 type composite. Finite element analysis and the ceramic injection molding(CIM) method were used for optimal design and fabrication. PZflex simulation tool derived the composite's piezoelectric properties, revealing that increased porosity reduced d₃₃ and d₃₁ but increased HFOM. The aspect ratio of PZT rods was selected by calculating the coupling factor. The fabricated composite had a higher HFOM value (4050(10–15 Pa) at 12 % porosity) than dense 1–3 type PZT-polymer composites. This study demonstrates the effectiveness of finite element analysis and CIM in designing high-performance piezoelectric composites, with potential for various future applications.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 4","pages":"Article 117046"},"PeriodicalIF":5.8,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142657696","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Effect of MnO2 content on the growth and electric properties of <110>c-oriented 0.85(Bi0.5Na0.5)TiO3-0.15BaTiO3 single crystals fabricated by solid-state crystal growth method","authors":"Ichiro Fujii,&nbsp;Ryohei Yuzawa,&nbsp;Shunsuke Kamimura,&nbsp;Shintaro Ueno,&nbsp;Satoshi Wada","doi":"10.1016/j.jeurceramsoc.2024.117043","DOIUrl":"10.1016/j.jeurceramsoc.2024.117043","url":null,"abstract":"<div><div>&lt;110&gt;_c-oriented 0.85(Bi_0.5Na_0.5)TiO₃-0.15BaTiO₃ + x wt%MnO₂ (x = 0 – 0.5) single crystals were fabricated by a solid-state crystal growth method, and the effect of the MnO₂ content on crystal growth and electric properties were investigated. Single crystals with a size of about 2 mm×3 mm×0.4 mm were obtained at x = 0 – 0.1. The temperature dependence of the dielectric properties of the single crystals at x = 0 – 0.1 revealed depolarization temperatures of 218 – 220 ˚C and the temperatures of the maximum dielectric constant of 254 – 261 ˚C. At x = 0.1, a ferroelectric polarization – electric field loop and a strain – electric field curve were observed, and the piezoelectric constant d₃₃ was 118 pC/N. The d₃₃ value was larger than to that of reported &lt;110&gt;_c-oriented ceramics but smaller than &lt;001&gt;_c-oriented ceramics, which suggested that 0.85(Bi_0.5Na_0.5)TiO₃-0.15BaTiO₃ was an extender ferroelectric material.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117043"},"PeriodicalIF":5.8,"publicationDate":"2024-10-31","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142586438","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Temperature stable (1-x)BaAl2Si2O8-xBa3V2O8 (0.2 ≤ x ≤ 0.5) microwave dielectric composite ceramics for LTCC applications","authors":"Wei Wang ,&nbsp;Qingyao Wang ,&nbsp;Diming Xu ,&nbsp;Zhongqi Shi ,&nbsp;Tiezhu Guo ,&nbsp;Fayaz Hussain ,&nbsp;Moustafa Adel Darwish ,&nbsp;Tao Zhou ,&nbsp;Yawei Chen ,&nbsp;Qixin Liang ,&nbsp;Meirong Zhang ,&nbsp;Di Zhou","doi":"10.1016/j.jeurceramsoc.2024.117042","DOIUrl":"10.1016/j.jeurceramsoc.2024.117042","url":null,"abstract":"<div><div>BaAl₂Si₂O₈ microwave dielectric ceramics possess dielectric properties of low permittivity (<em>ε</em>_r) and low loss, coupled with low synthesis cost, making them promising for commercialization. However, the hexagonal structure undergoes high-temperature phase transitions that deteriorate thermal shock resistance and durability, hindering its practical use. In this work, we report temperature-stable BaAl₂Si₂O₈-Ba₃V₂O₈ low temperature co-fired ceramics (LTCC). The combination of Ba₃V₂O₈ and G9 glass achieved a near-zero <em>τ</em>_<em>f</em> and a thermal expansion coefficient of ∼ 8.5 ppm/℃, significantly enhancing the temperature stability of BaAl₂Si₂O₈ ceramics. By employing ion substitution and enhancing lattice disorder, the components of G9 glass were strategically designed to successfully induce hexagonal-to-monoclinic transformation of BaAl₂Si₂O₈ phase. The dielectric properties of 0.5BaAl₂Si₂O₈-0.5Ba₃V₂O₈-9 wt% G9 sintered at 900 ℃ were <em>ε</em>_r ∼9, <em>Q</em>×<em>f</em> ∼22,000 GHz and <em>τ</em>_<em>f</em> ∼ +1.9 ppm/℃. Good chemical compatibility with silver powders was confirmed by further investigation of the co-firing behavior. This work provides attractive candidate for BaAl₂Si₂O₈-based LTCCs and an available approach for modifying BaAl₂Si₂O₈ ceramics.</div></div>","PeriodicalId":17408,"journal":{"name":"Journal of The European Ceramic Society","volume":"45 3","pages":"Article 117042"},"PeriodicalIF":5.8,"publicationDate":"2024-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142561491","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"材料科学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}