Electrospun polymeric piezoelectric fibers have a considerable potential for shape‐adaptive mechanical energy harvesting and self‐powered sensing in biomedical, wearable, and industrial applications. However, their unsatisfactory piezoelectric performance remains an issue to be overcome. While strategies for increasing the crystallinity of electroactive β phases have thus far been the major focus in realizing enhanced piezoelectric performance, tailoring the fiber morphology can also be a promising alternative. Herein, a design strategy that combines the nonsolvent‐induced phase separation of a polymer/solvent/water ternary system and electrospinning for fabricating piezoelectric poly(vinylidene fluoride‐trifluoroethylene) (P(VDF‐TrFE) fibers with surface porosity under ambient humidity is presented. Notably, electrospun P(VDF‐TrFE) fibers with higher surface porosity outperform their smooth‐surfaced counterparts with a higher β phase content in terms of output voltage and power generation. Theoretical and numerical studies also underpin the contribution of the structural porosity to the harvesting performance, which is attributable to local stress concentration and reduced dielectric constant due to the air in the pores. This porous fiber design can broaden the application prospects of shape‐adaptive energy harvesting and self‐powered sensing based on piezoelectric polymer fibers with enhanced voltage and power performance, as successfully demonstrated in this work by developing a communication system based on self‐powered motion sensing.

with AlF 3 as a flux (1400-1420°C, 1 h). Neutron diffraction and powder XRD, and luminescence and XANES spectroscopy reveal its structural and optical properties as a function of Eu concentration. The phosphor crystallizes in the space group P6 3 /mmc. BaMgAl 10 O 17 :Eu 2+ exhibits a strong emission band around 450 nm (254 nm excitation). The critical Eu concentration is estimated from the concentration dependencies of the absolute quantum efficiency and the intensity of the photoluminescence. The intensity of the blue luminescence reaches a maximum at 11.6 mol% Eu. The phosphor is of great interest for use in plasma display panels.

Objective To evaluate the vertical relationship between the maxillary sinus floor (MSF) and the maxillary posterior teeth (MPT) according to an anterior overbite. Settings and Sample Population The patients were divided into three groups according to an anterior overbite. The open bite group (OBG) included patients with an anterior overbite of ≤0 mm, the normal overbite group (NBG) included patients with an overbite of 0‐3 mm, and the deep bite group (DBG) included patients with an overbite ≥3 mm. Thirty patients were randomly matched into each group based on age and sex. Materials and Methods The distances and vertical relationship between the MSF and the MPT was analysed using cone‐beam computer tomography. The vertical relationship between the two was classified as either favourable or unfavourable for the intrusion of the posterior teeth. Results A higher ratio of patients in the OBG had MPT positioned close to the MSF than the DBG. Intrusion of the posterior teeth was unfavourable for an average of 87.2%, 77.2% and 70.2% molars in the OBG, NBG and DBG, respectively. Conclusions The vertical distance between the MSF and the MPT is associated with an anterior overbite. The posterior teeth were in an unfavourable position for the orthodontic intrusion in the OBG as compared to the other groups. Additional caution is needed when planning orthodontic intrusion treatment for patients with an anterior open bite. But, there were some individual variations within each group.

The authors reveal the mechanisms of degradation of capacity, charge voltage, and discharge voltage of commercially‐available high‐nickel cathode material when it is cycled without a voltage margin by two different charge protocols: constant‐current charging and constant‐current, constant‐voltage charging. With repeated constant‐current charging, the cathode material changes to a non‐periodic cation‐mixed state, which causes a relatively low voltage degradation, whereas during constant‐current, constant‐voltage charging, the cathode material changes from a layered structure to a periodic cation‐mixed spinel‐like phase, with consequent severe voltage decay. This decay results from a reduction in the equilibrium electrode potential and an increase of overpotential which are aggravated in a periodic cation‐mixed state. The findings provide insights into the use of excess Li without charge‐voltage margin in high‐Ni cathode materials.

Data. -The title compound is characterized by Raman spectroscopy, powder neutron diffraction, and powder XRD at 298 K. The La atoms are located only on Bi sites in the perovskite units. The refinement results and spontaneous polarization calculations indicate that a monoclinic model (space group B1a1) is more suitable than an orthorhombic model (space group B2cb) as crystal system of the title compound. -(JEON, M. K.; KIM, Y.-I.; NAHM, S.-H.; WOO*, S. I.; J. Phys. Chem. B 109 (2005) 2, 968-972; Dep.