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Lingping Kong Jue Gong Qingyang Hu Francesco Capitani Anna Celeste Takanori Hattori Asami Sano-Furukawa Nana Li Wenge Yang Gang Liu Ho-kwang Mao 《Advanced functional materials》2021,31(9):2009131
The soft nature of organic–inorganic halide perovskites renders their lattice particularly tunable to external stimuli such as pressure, undoubtedly offering an effective way to modify their structure for extraordinary optoelectronic properties. Here, using the methylammonium lead iodide as a representative exploratory platform, it is observed that the pressure-driven lattice disorder can be significantly suppressed via hydrogen isotope effect, which is crucial for better optical and mechanical properties previously unattainable. By a comprehensive in situ neutron/synchrotron-based analysis and optical characterizations, a remarkable photoluminescence (PL) enhancement by threefold is convinced in deuterated CD3ND3PbI3, which also shows much greater structural robustness with retainable PL after high peak-pressure compression–decompression cycle. With the first-principles calculations, an atomic level understanding of the strong correlation among the organic sublattice and lead iodide octahedral framework and structural photonics is proposed, where the less dynamic CD3ND3+ cations are vital to maintain the long-range crystalline order through steric and Coulombic interactions. These results also show that CD3ND3PbI3-based solar cell has comparable photovoltaic performance as CH3NH3PbI3-based device but exhibits considerably slower degradation behavior, thus representing a paradigm by suggesting isotope-functionalized perovskite materials for better materials-by-design and more stable photovoltaic application. 相似文献
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《Ceramics International》2022,48(6):7748-7758
Micromechanics model, finite element (FE) simulation of microindentation and machine learning were deployed to predict the mechanical properties of Cu–Al2O3 nanocomposites. The micromechanical model was developed based on the rule of mixture and grain and grain boundary sizes evolution to predict the elastic modulus of the produced nanocomposites. Then, a FE model was developed to simulate the microindentation test. The input for the FE model was the elastic modulus that was computed using the micromechanics model and wide range of yield and tangent stresses values. Finally, the output load-displacement response from the FE model, the elastic modulus, the yield and tangent strengths used for the FE simulations, and the residual indentation depth were used to train the machine learning model (Random vector functional link network) for the prediction of the yield and tangent stresses of the produced nanocomposites. Cu–Al2O3 nanocomposites with different Al2O3 concentration were manufactured using insitu chemical method to validate the proposed model. After training the model, the microindentation experimental load-displacement curve for Cu–Al2O3 nanocomposites was fed to the machine learning model and the mechanical properties were obtained. The obtained mechanical properties were in very good agreement with the experimental ones achieving 0.99 coefficient of determination R2 for the yield strength. 相似文献
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《Ceramics International》2022,48(21):31491-31499
In this study, an all-solid-state electrochromic device (ECD) with the structure of ITO/WO3/Al2SiO5/NiOx/ITO was prepared, and the effect of the Al2SiO5 solid electrolyte thicknesses on the opto-electrical performance was investigated. The microstructure and surface morphology were characterized using XRD, SEM and AFM, and the surface morphology and degree of surface looseness demonstrate a significant influence on the opto-electrical properties of ECDs. The charge transfer dynamics at the solid-solid interface were characterized using EIS to obtain an ionic conductivity of 4.637 × 10-8 S/cm. CV, CA and UV–Visible spectra were employed to record the in situ electrochemical and optical properties. The results revealed that the highest optical modulation was 44.58%, the coloring and bleaching times were 14.8 s and 3.7 s, and the highest coloring efficiency was 98.17 cm2/C, which indicates that excellent opto-electrical properties were obtained. When the thickness increases, the degree of surface dense morphology transforms, and the loose morphology is more favorable for ion conductivity, which improves the opto-electrical properties. The results in this study provide insights into the understanding of Al3+-based all-solid-state ECDs, which promote the exploration of new types of Al3+ ionic conductors for all-solid-state ECDs. 相似文献
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In the current research, a modern learning machine algorithm named “Weighted Regularized Extreme Learning Machine (WRELM)" is implemented for the first time for the simulation of the coefficient of discharge of side slots. For this purpose, an effective variable on the coefficient of discharge of side slots is firstly introduced, then five distinctive WRELM models are produced by it for the estimation of the coefficient. In the next stage, a database is created for verification of WRELM results. it should be mentioned that 70% of the data are utilized for training the WRELM models, while the rest (i.e. 30%) for testing them. After that, the optimal number of hidden layer neurons as well as the best activation function of the WRELM algorithm are chosen. In addition, the best regularization parameter and also the weight function of the WRELM are achieved. By conducting a sensitivity analysis, the most effective variable for the simulation of the coefficient of discharge along with the WRELM superior model is introduced. The WRELM superior model estimates values of the coefficient of discharge with the maximum exactness and the highest correlation. For instance, the estimations of the correlation coefficient and scatter index for this model are computed to be 0.930 and 0.051, respectively. The sensitivity analysis shows that the ratio of the side slot crest height to its length and the Froude number should be considered as the most important input variables. A comparison between the WRELM with the ELM displays that the former works much better. Furthermore, an uncertainty analysis is executed for both models. Eventually, an equation is suggested for the estimation of the coefficient of discharge and a partial derivative sensitivity analysis is performed on it. 相似文献
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Wen Ma Yuanming Gao Jingxin Zhang Yu Bai Ruiling Jia Hongying Dong Ruijun Wang Manyu Bao 《Journal of the European Ceramic Society》2021,41(4):2734-2745
Srx(Zr0.9Y0.05Yb0.05)O1.95+x (x=1.0, 0.9, 0.8, 0.7) ceramics were prepared by solid state reaction sintering. The sintered Sr1.0(Zr0.9Y0.05Yb0.05)O2.95 is a single-phase solid solution while the sintered Srx(Zr0.9Y0.05Yb0.05)O1.95+x (x=0.9?0.7) are composites, and a significant grain growth inhibition is observed in the sintered Srx(Zr0.9Y0.05Yb0.05)O1.95+x (x=1.0, 0.9). Rare-earth elements distribution in the bulk materials indicates that Yb and Y preferentially substitute Zr-sites in SrZrO3, and the highest solubility of RE2O3 in pure SrZrO3 is ~0.8 mol%. The sintered Srx(Zr0.9Y0.05Yb0.05)O1.95+x have high thermal expansion coefficients up to ~11.0×10?6 K-1 (1200°C). Sr0.8(Zr0.9Y0.05Yb0.05)O2.75 has the lowest thermal conductivity of 1.38 W·m-1·K-1 at 800°C. Srx(Zr0.9Y0.05Yb0.05)O1.95+x (x=1.0, 0.9, 0.8) show no phase transition from 600 to 1400°C, whereas Srx(Zr0.9Y0.05Yb0.05)O1.95+x (x=0.9, 0.8) have excellent high-temperature phase stability over the whole investigated temperature range. Therefore, Srx(Zr0.9Y0.05Yb0.05)O1.95+x (x=1.0, 0.9, 0.8) are considered as promising TBCs materials that might be operated at higher temperatures compared to YSZ. 相似文献