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Figure 6. a) Schematic illustration of the electron transport pathway in a SEI-wrapped 3D CNT NAs-sulfur cathode. Reproduced with permission. [99] Copyright 2017, Wiley-VCH. b) SEM images of CC@ZnO anode after cycling test without (b 1 ) and with (b 2 ) 3D CF NAs. Reproduced with permission. [103] Copyright 2016, Wiley-VCH. c) The local current density and electric field distribution of Zn anode on a planar current collector (c 1 ) and a 3D current collector (c 2 ). d) Regulated growth of SEI on 3D titanate NAs with ether electrolyte. e) Discharge/charge profiles of the Na 2 Ti 2 O 5 anode with ether electrolyte (inset: HRTEM image of the fully discharged Na 2 Ti 2 O 5 NSs). d,e) Reproduced with permission. [112] Copyright 2019, Wiley-VCH.

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A broadband and polarization-insensitive high impedance surface (HIS) metamaterial absorber (MA) based on octagonal ring-shaped resistive patches is presented. The absorber is investigated theoretically, experimentally and by simulation. The simulated results indicate that this structure obtains 10.28 GHz-wide absorption from 3.65 to 13.93 GHz with absorptivity larger than 90% at the normal incidence. Experimental results are in accordance with those of the simulation results. The electromagnetic (EM) field distributions and the plots of surface power loss density have been illustrated to analyze the absorption mechanism of the structure. Further simulations of the absorptivity of the proposed absorber with different surface resistances and substrate thicknesses indicate that there exist optimal values for the design. The polarization-insensitive feature and the properties under oblique incidence are also investigated. Finally, the interference theory is introduced to analyze and interpret the broadband absorption mechanism at both normal and oblique incidence. The calculated absorption rates of the proposed absorber coincide well with the simulated results. Therefore, the simulated and experimental results verify the validity of the theoretically analytical method for this type of broadband absorber.Index Terms-High impedance surface (HIS), metamaterial absorber (MA), broadband, microwave, interference theory.

Abstract.A series of tetradentate pyridyl-imine terminated Schiff-base ligands has been investigated for their ability in the catalytic oxidation of alcohols when combined with copper bromide (CuBr 2 ) and 2,2,6,6-tetramethylpiperidyl-1-oxy (TEMPO). Analogous bidentate ligands showed poorer catalytic activity and the ratio of Cu:ligand was of crucial importance in maintaining high yields. The polydimethylsiloxane (PDMS) derived pyridyl-imine terminated ligand combined with copper (II) ions affords an effective and selective catalyst for aerobic oxidations of primary and secondary alcohols under aqueous conditions. Preliminary mechanistic studies suggest that bimetallic complexes may be playing a role in the catalytic transformation. Graphical Abstract1

We herein report kinetic studies on UV-visible radiation (315 ≤ λ ≤ 700 nm) enhanced uptake of Hg0(g) by proxies for reactive components of mineral dust (nano γ-Fe2O3, α-FeOOH, α-Fe2O3 and Fe3O4) and propose possible reaction mechanisms.

Vanadium-based cathodes have attracted great interest in aqueous zinc ion batteries (AZIBs) due to their large capacities, good rate performance and facile synthesis in large scale. However, their practical application is greatly hampered by vanadium dissolution issue in conventional dilute electrolytes. Herein, taking a new potassium vanadate K0.486V2O5 (KVO) cathode with large interlayer spacing (~ 0.95 nm) and high capacity as an example, we propose that the cycle life of vanadates can be greatly upgraded in AZIBs by regulating the concentration of ZnCl2 electrolyte, but with no need to approach “water-in-salt” threshold. With the optimized moderate concentration of 15 m ZnCl2 electrolyte, the KVO exhibits the best cycling stability with ~ 95.02% capacity retention after 1400 cycles. We further design a novel sodium carboxymethyl cellulose (CMC)-moderate concentration ZnCl2 gel electrolyte with high ionic conductivity of 10.08 mS cm−1 for the first time and assemble a quasi-solid-state AZIB. This device is bendable with remarkable energy density (268.2 Wh kg−1), excellent stability (97.35% after 2800 cycles), low self-discharge rate, and good environmental (temperature, pressure) suitability, and is capable of powering small electronics. The device also exhibits good electrochemical performance with high KVO mass loading (5 and 10 mg cm−2). Our work sheds light on the feasibility of using moderately concentrated electrolyte to address the stability issue of aqueous soluble electrode materials.