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Aqueous electrolytes are attractive as energy storage devices due to their high conductivity, environmental friendliness, and sustainability. However, their use is limited by the evolution potential of 1.23 V. A Tween 20-based sustainable microemulsion electrolyte has been proposed; the hydrophobic tail of the surfactant could array on the surface of a hydrophobic electrode, concentrating an oil layer to increase the operating potential, achieving 2.9 V operating voltage (same level as organic electrolyte), while persevering the odds of aqueous electrolytes. [ABSTRACT FROM AUTHOR]

Quickly discharged supercapacitors are often found to show voltages that increase with time ranging from minutes to several hours. People attribute this to the special structure of the supercapacitor; however, we propose an alternative explanation. A physical model was developed to explain the phenomenon and further reveal the working mechanism of supercapacitor discharge, thus providing a guide for improving the performance of supercapacitors. [ABSTRACT FROM AUTHOR]

In this work, a new method for hand character gesture recognition based on a single millimetre‐wave radar chip is proposed. Most current radar‐based gesture recognition approaches use Doppler spectrograms or the feature extraction of Doppler spectrograms. In contrast, the authors propose using the trajectory points of gesture movements. Compared with the previous methods, the variations in the gesture movement speed, distance and direction during data acquisition have relatively little impact on the generated trajectories. The character trajectories drawn by gestures in the air output a fixed shape, and this fixed output facilitates the classification of gestures at a later stage. In this work, a single millimetre‐wave radar is used to collect data and a three‐dimensional fast Fourier Transform (3D‐FFT) algorithm is used to obtain the gesture trajectories. For the trajectory points, a trajectory conversion image method is proposed and finally the improved Xception network proposed in this work is used for image recognition. Compared with traditional methods, the proposed method does not require large‐scale data acquisition to facilitate different users. This work is concluded by recognising hand character gestures and comparing them with other commonly used classification methods to verify the gesture recognition accuracy of the proposed method. [ABSTRACT FROM AUTHOR]

Abstract: Nanocrystalline TiO2 films modified with WO3 were fabricated by depositing TiO2 suspension containing small amounts of ammonium tungstate solution. The films were characterized with X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), photoluminescence (PL) spectrum, Brunauer–Emmett–Teller (BET) surface area, zeta potential and transient photovoltage measurements. The results indicated that the modification of WO3 extremely reduced the surface states of TiO2 and suppressed charge recombination significantly. Compared with unmodified TiO2 film, the suppression of the interfacial charge recombination and the increased driving force of electron injection contributed to the improved photovoltaic performance of TiO2 films modified with WO3. The power conversion efficiency increased as a function of WO3 content when its concentration was less than 0.5wt.%. The highest conversion efficiency was obtained with TiO2 films modified with 0.5wt.% WO3, with an increase of 18% improvement in the conversion efficiency than the blank. However, further increasing amount of WO3 resulted in a decrease in the photocurrent thus reducing the overall conversion efficiency. The retardation of electron injection by the thicker overlayer of WO3 together with the decrease of the dye loading was responsible for the loss of the efficiency for cells modified with higher concentrations of WO3. [Copyright &y& Elsevier]