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Static three-chamber ZnI2redox batteries are designed and analyzed electrochemically. The reversibility of the zinc plating/stripping process is evaluated by monitoring the cathodic/anodic peaks in the cyclic voltammograms. The electrochemical redox process of iodide on the cathode is analyzed based on the impedance spectra. The reversibility of zinc plating/stripping is related to I2adsorption and improving performance of three-chamber ZnI2redox battery could be attributed to the isolation of redox ions. The multi-electrolyte battery limits the influence of I2adsorption and delivers better performance including of the high discharging voltage and power density.

Wireless power transfer chargers for electric bicycles (EBs) have many advantages over transitional plug-in systems. However, to meet the charge requirements, the traditional charger needs a dedicated inverter to achieve constant current (CC) output or constant voltage (CV) output. A hybrid topology-based EB charging strategy is proposed using a single high-frequency inverter (HFI) to charge massive EBs, and one charging stand can be shared to charge EBs with various specifications of batteries. Configurable CC and CV outputs can be realized by turning on/off two ac switches without adopting sophisticated control schemes or wireless communication links. Besides, zero phase angle switching of HFI can be realized, and then the system efficiency is increased. Finally, the proposed method is verified by experiments with various charging conditions. The results show that the fluctuation margins of charging currents and charging voltages in the whole charging process are both less than 2.5% and the maximum efficiency reaches 91.90%. With the merit of the proposed approach, the reduction of construction cost and the control complexity is achieved. Thus, it might be one of the most promising solutions for charging massive EBs in some regions like China.

The 3D Swave velocity of shallow structures, especially the quaternary sediments at 0–1 km near the surface, is an important issue of concern in urban planning and construction for seismic hazard assessment and disaster mitigation. Due to the facility and less dependence on the site environment, noise‐based technique is an ideal way to acquire the fine structure of urban sedimentary basin. Based on the dense array composed of more than 900 stations deployed in Tongzhou at a local scale of 20 × 40 km2, we prove that the lateral variation of the phase velocity of multimode surface waves can be estimated directly with sufficient accuracy by beamforming seismic noise with moving subarrays. Rayleigh wave phase velocity maps, at frequencies between 0.3 and 2.5 Hz for the fundamental mode as well as 0.8 and 3.0 Hz for the first overtone, are obtained. The 3D Swave velocity model at 0–1‐km depth with lateral resolution of 1 km is then established by inverting phase velocity maps of the two modes. The sediment thickness is delineated by the impedance interface given by microtremor H/V(horizontal‐to‐vertical) spectral ratio. The proposed model is in good agreement with the distribution of tectonic units. The sediment thickness of Daxing high and two sags around Gantang and Xiadian are, respectively, 100–400 and 400–600 m, which correlates well with the 1 km/s isosurface of Swave velocity. The model presents some evidence on the extension of Daxing fault along NE direction. Large cities are usually built on sedimentary basins which are prone to capture and amplify seismic energy with the result of larger damage. The main factors to determine the site amplification are the depth to basement and Swave velocity of the sedimentary layer. The combination of beamforming (BF) and microtremor H/Vis suggested to build the high‐resolution 3D Swave velocity model of the basin. We prove that the lateral variation of the Rayleigh wave phase velocity of the fundamental mode as well as the first overtone can be estimated directly with sufficient accuracy by BF seismic noise, without tomographic inversion. The 3D Swave velocity model can thereby be established with high resolution by inverting the phase velocity maps of multimode surface waves. The depth to basement is delineated by the impedance interface given by microtremor H/V. The 3D Swave velocity and the depth to basement of Tongzhou, the subcenter of Beijing, is established using the data at a dense array composed of more than 900 stations using suggested schemes. The 3D Swave velocity model could provide the basic information for seismic hazard assessment and disaster mitigation, therefore fulfilling the requirements in urban planning and construction. We prove that the 2D phase velocity maps of the multimode Rayleigh waves can be extracted directly by beamforming the ambient noiseA 3D Vs model of Tongzhou is established by inverting the phase velocity maps of the fundamental and the first overtone of Rayleigh wavesThe sediment thickness is delineated by the interface with strong impedance contrast obtained by H/Vspectral ratio We prove that the 2D phase velocity maps of the multimode Rayleigh waves can be extracted directly by beamforming the ambient noise A 3D Vs model of Tongzhou is established by inverting the phase velocity maps of the fundamental and the first overtone of Rayleigh waves The sediment thickness is delineated by the interface with strong impedance contrast obtained by H/Vspectral ratio