A carefully designed test cell platform with a new electrode structure is utilized to determine the intrinsic surface catalytic properties of an electrode. With this design, the electrocatalytic activity and stability of an La 0.6 Sr 0.4 Co 0.2 Fe 0.8 O 3Àd (LSCF) cathode is enhanced by a dense thin La 0.85 Sr 0.15 MnO 3AEd (LSM) coating, suggesting that an efficient electrode architecture has been demonstrated that can make effective use of desirable properties of two different materials: fast ionic and electronic transport in the backbone (LSCF) and facile surface kinetics on the thin-film coating (LSM). Theoretical analyses suggest that the enhanced electrocatalytic activity of LSM-coated LSCF is attributed possibly to surface activation under cathodic polarization due to the promotion of oxygen adsorption and/or dissociation by the surface layer and the dramatically increased oxygen vacancy population in the surface film. Further, the observed time-dependent activation over a few hundreds of hours and durability are likely associated with the formation of a favorable hybrid surface phase intermediate between LSM and LSCF. This efficient electrode architecture was successfully applied to the state-of-the-art LSCF-based cathodes by a simple solution infiltration process, achieving reduced interfacial resistance and improved stability under fuel cell operating conditions.

Lead-free piezoelectric thick films of (K0.5Na0.5)NbO3 were fabricated by aerosol-deposition method. The thickness of KNN film was 7.1μm and fully dense films were obtained. The dielectric constants ε3T∕ε0 of the as-deposited and annealed films at 1kHz were 116 and 545, respectively, which are higher than any previously reported values for lead-free piezoelectric thin/thick films, either without or with heat treatment. The ferroelectric properties were improved after annealing and the maximum values of Pr=8.1μC∕cm3 and Ec=100kV∕cm were achieved. These values are markedly superior to those of sintered KNN ceramic counterparts.

The chemical changes in poly(methylmethacrylate) (PMMA) caused by irradiation with deep ultraviolet (UV), x-ray, electron, and proton beams were studied by gel permeation chromatography, Fourier-transform infrared, and UV spectroscopy. The quantitative analysis of spectroscopic changes (Beer’s law) demonstrated a 1:1 correspondence between the disappearance of ester groups and the generation of double bonds in the polymer chain by all types of radiation. The ratio of main chain scission to changes in the number of ester groups and unsaturated bonds was compared to determine the characteristics of degradation of PMMA by the different types of radiation. This ratio for deep UV data was very close to the quantum yield of main chain scission of PMMA as reported in the literature. High-energy radiation was ∼10× more efficient than deep UV in causing main chain scission with removal of fewer ester groups. Protons induced more main chain scission than electrons. X-ray irradiation was the most efficient at causing main chain scission of the four different types of radiation.

A high-performance magneto-mechano-triboelectric nanogenerator (MMTEG) is demonstrated for powering a wireless indoor positioning system.

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