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    Energy-storage properties and electrocaloric effects of Pb(1-3x/2)LaxZr0.85Ti0.15O3 antiferroelectric thick films

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    1-µm-Pb(1-3x/2)LaxZr0.85Ti0.15O3 (PLZT) antiferroelectric (AFE) thick films with x = 0.08, 0.10, 0.12, and 0.14 were deposited on LaNiO3/Si (100) substrates by a sol-gel method. The dielectric properties, energy-storage performance, electrocaloric effect, and leakage current behavior were investigated in detail. With increasing La content, dielectric constant and saturated polarizations of the thick films were gradually decreased. A maximum recoverable energy-storage density of 38 J/cm3 and efficiency of 71% were achieved in the thick films with x = 0.12 at room temperature. Moreover, a large reversible adiabatic temperature change ∆T = 25.0 o C was presented in the thick films with x = 0.08 at 127 o C at 990 kV/cm. All the samples had a lower leakage current density below 10- 6 A/cm2 at room temperature. These results indicated that the PLZT AFE thick films could be a potential candidate for applications in high energy-storage density capacitors and cooling devices

    Enhanced energy-storage performance and electrocaloric effect in compositionally graded Pb(1−3x/2)LaxZr0.85Ti0.15O3 antiferroelectric thick films

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    The compositionally graded multilayer Pb(1−3x/2)LaxZr0.85Ti0.15O3 (PLZT) antiferroelectric (AFE) thick films were deposited on LaNiO3/Si (100) substrates by using a sol–gel method. The effect of gradient sequence on dielectric properties, energy-storage performance, and electrocaloric effect (ECE) was investigated in detail. It is found that the compositionally graded films exhibited a significant enhancement in dielectric properties, energy-storage performance and ECE, which was, in contrast to the single-composition PLZT film, contributed by the strain and the gradient of polarization near the interfaces between the adjacent layers. A recoverable energy-storage density of 44 J/cm3 and efficiency of 71% was obtained in the up-graded PLZT AFE thick film at 1950 kV/cm. A giant reversible adiabatic temperature change of ∆T=28 °C at room temperature at 900 kV/cm was also achieved in the up-graded film. Moreover, all the thick films displayed a small leakage current density below 10−6 A/cm2 at room temperature. Thus, the compositionally graded PLZT AFE thick films with a large recoverable energy-storage density and a giant ECE could be a potential candidate for the applications in high energy-storage density capacitors and cooling devices

    Empirical Study of Deep Learning for Text Classification in Legal Document Review

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    Predictive coding has been widely used in legal matters to find relevant or privileged documents in large sets of electronically stored information. It saves the time and cost significantly. Logistic Regression (LR) and Support Vector Machines (SVM) are two popular machine learning algorithms used in predictive coding. Recently, deep learning received a lot of attentions in many industries. This paper reports our preliminary studies in using deep learning in legal document review. Specifically, we conducted experiments to compare deep learning results with results obtained using a SVM algorithm on the four datasets of real legal matters. Our results showed that CNN performed better with larger volume of training dataset and should be a fit method in the text classification in legal industry.Comment: 2018 IEEE International Conference on Big Data (Big Data