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Articles you may be interested inStructural and dielectric properties of laser ablated BaTiO3 films deposited over electrophoretically dispersed CoFe2O4 grains Raman spectroscopic study of Na1/2Bi1/2TiO3-x%BaTiO3 single crystals as a function of temperature and compositionThe low Curie temperature (T c ¼ 130 C) of bulk BaTiO 3 greatly limits its applications. In this work, the phase structures of BaTiO 3 nanoparticles with sizes ranging from 2.5 nm to 10 nm were studied at various temperatures by using aberration-corrected transmission electron microscopy (TEM) equipped with an in-situ heating holder. The results implied that each BaTiO 3 nanoparticle was composed of different phases, and the ferroelectric ones were observed in the shells due to the complicated surface structure. The ferroelectric phases in BaTiO 3 nanoparticles remained at 600 C, suggesting a significant increase of T c . Based on the in-situ TEM results and the data reported by others, temperature-size phase diagrams for BaTiO 3 particles and ceramics were proposed, showing that the phase transition became diffused and the T c obviously increased with decreasing size. The present work sheds light on the design and fabrication of advanced devices for high temperature applications.

Different amounts of silver (0.5–10 wt%) have been mixed with EIA X7R‐type ceramic powders based on barium titanate. The XRD analysis indicated that no phases other than BaTiO3 and silver were present in the doped ceramics; it further suggested that no reaction took place between BaTiO3 and silver during calcination and sintering. SEM observation showed that the silver particles presented island distribution in the BaTiO3 ceramic matrix. The densification and dielectric properties of the silver‐doped ceramics in disk form were investigated. A large amount of silver addition (>1 wt%) was found to improve the sintered density and dielectric properties. The temperature coefficient of capacitors of the ceramics doped with 10 wt% silver still met the X7R characteristics, and the dielectric constant of the ceramics at room temperature was >6000, which is the highest dielectric constant in the BaTiO3‐based X7R system.

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Cellular respiration is a worthwhile criterion to evaluate mitochondrial dysfunction by measuring the dissolved oxygen. However, most of the existing sensing strategies merely report extracellular (ec-) or intracellular (ic-) O2 rather than intramitochondrial (im-) O2 . Herein we present a method to assess tumor mitochondrial dysfunction with three phosphorescent nanosensors, which respond to ec-, ic-, and im-O2 . Time-resolved luminescence is applied to determine the respective oxygen consumption rates (OCRs) under varying respiratory conditions. Data obtained for the OCRs and on (intra)cellular O2 gradients demonstrate that mitochondria in tumor cells are distinctly less active than those of healthy cells, resulting from restrained glucose utilization of and physical injury to the mitochondria. We believe that such a site-resolved sensing strategy can be applied to numerous other situations, for example to evaluate the adverse effects of drug candidates.

Multilayer ceramic capacitors (MLCCs) are attracting great interest recently, especially in energy-storage applications due to their high volumetric capacitance, high power density, and fast charge-discharge capability. However, the low dielectric breakdown strength of ferroelectric ceramics always leads to a low discharge energy density, which limits their applications in high-voltage energy-storage systems. In this work, a phase-field electromechanical breakdown model is introduced to give a fundamental understanding of the dielectric breakdown behavior of MLCCs and provide a resource-efficient design strategy for the structure of MLCCs to enhance their dielectric breakdown strength and discharge energy density. Three types of margin lengths of 100 μm, 200 μm, and 400 μm are designed and applied on the MLCCs consisting of ten dielectric layers with the single-layer thickness of 11 μm, to confirm and practice our phase-field breakdown model. A large discharge energy density of 7.8 J cm−3 can be achieved under the applied electric field of 790 kV/cm, together with a high efficiency of 88% in a 400 μm-margin-length MLCC.

Abstract-We study emotion influence in large image social networks. We focus on users' emotions reflected by images that they have uploaded and social influence that plays a role in changing users' emotions. We first verify the existence of emotion influence in the image networks, and then propose a probabilistic factor graph based emotion influence model to answer the questions of "who influences whom". Employing a real network from Flickr as the basis in our empirical study, we evaluate the effectiveness of different factors in the proposed model with in-depth data analysis. The learned influence is fundamental for social network analysis and can be applied to many applications. We consider using the influence to help predict users' emotions and our experiments can significantly improve the prediction accuracy (3.0%-26.2%) over several alternative methods such as Naive Bayesian, SVM (Support Vector Machine) or traditional Graph Model. We further examine the behavior of the emotion influence model, and find that more social interactions correlate with higher emotion influence between two users, and the influence of negative emotions is stronger than positive ones.

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