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With the advent of 5G era, the high millimeter-wave frequency band, poor signal penetration and large loss make 5G communication more dependent on low dielectric constant materials. Therefore, the research and development of low dielectric polymer materials has become a hot spot in recent years. With its good chemical corrosion resistance, thermal stability, high dispersion and high mobility, titanium dioxide (Ti[O.sub.2]) as a high function fine inorganic material is doped in polymer systems to improve the electrical properties of polymer composites. In recent years, a large number of studies have used spherical Ti[O.sub.2] nanoparticles doped on the polymer matrix, however, there is almost no research on doping nanolinear Ti[O.sub.2] nanoparticles on the polymer matrix. Here, Ti[O.sub.2] nanowires were prepared by hydrothermal method, and the prepared Ti[O.sub.2] nanowires were added to polyimide (PI). Ti[O.sub.2]/PI monolayer and three-layer composite films with good dielectric and mechanical properties were prepared by in-situ polymerization. Fourier transform infrared spectoscopy, scanning electron microscopy and X-ray diffraction were used to characterize the structure and test the properties of the composites. During the initiation process, the thermal initiation reaction of the composite membrane was completed. The composite film with good mechanical properties and excellent dielectric properties were obtained by adding titanium oxide nanowires, which can meet the requirements of its use in the field of microelectronic devices. KEYWORDS dielectric properties, hydrothermal method, polyimide, Ti[O.sub.2], 1 | INTRODUCTION Polyimide (PI) is a class of high-performance polymer material characterized by the imide ring structure, with excellent thermal stability, chemical corrosion resistance, mechanical properties, and good dielectric [...]

In summary, Ni(OH)2 nanoflowers (Ni(OH)2 NFs) and Ni(OH)2 nanoflowers grown on Ni foan (Ni(OH)2 NFs@NF) were synthesised using a one‐step hydrothermal process. In energy storage applications, the Ni(OH)2 NFs@NF can be a useful electrode material. When utilized as a supercapacitor electrode material, the Ni(OH)2 NFs@NF shows a discharge specific capacity of 100.0 F g−1, which is greater than that of pure Ni(OH)2 NFs (27.3 F g−1) at an applied current density of 0.4 A g−1. In lithium‐ion batteries (LIBs), the Ni(OH)2 NFs@NF composite is used as an anode and has primordial discharge and charge capacities of 1595.2 and 1104.3 mAh g−1, individually. Lithium‐ion batteries are made possible by the Ni(OH)2 NFs@NF anode, which has an amazing capacity of 213.8 mAh g−1 after 50 cycles. Ni(OH)2 NFs@NF are employed as sodium ion batteries(SIBs) anodes, and Ni(OH)2 NFs@NF has 440.0 and 217.9 mAh g−1 for the primal discharge and charge capacities, individually. The Ni(OH)2 NFs@NF anode with a high capacity of 122.7 mAh g−1 following 50 cycling numbers allows for construction of lithium ion batteries,Ni(OH)2 NFs@NF has better sodium and lithium ion storage capacity than Ni(OH)2 NFs.The content of this study is intended to provide a reference for future research on nickel hydroxide flexible electrodes. [ABSTRACT FROM AUTHOR]

With the advent of 5G era, the high millimeter‐wave frequency band, poor signal penetration and large loss make 5G communication more dependent on low dielectric constant materials. Therefore, the research and development of low dielectric polymer materials has become a hot spot in recent years. With its good chemical corrosion resistance, thermal stability, high dispersion and high mobility, titanium dioxide (TiO2) as a high function fine inorganic material is doped in polymer systems to improve the electrical properties of polymer composites. In recent years, a large number of studies have used spherical TiO2 nanoparticles doped on the polymer matrix, however, there is almost no research on doping nanolinear TiO2 nanoparticles on the polymer matrix. Here, TiO2 nanowires were prepared by hydrothermal method, and the prepared TiO2 nanowires were added to polyimide (PI). TiO2/PI monolayer and three‐layer composite films with good dielectric and mechanical properties were prepared by in‐situ polymerization. Fourier transform infrared spectoscopy, scanning electron microscopy and X‐ray diffraction were used to characterize the structure and test the properties of the composites. During the initiation process, the thermal initiation reaction of the composite membrane was completed. The composite film with good mechanical properties and excellent dielectric properties were obtained by adding titanium oxide nanowires, which can meet the requirements of its use in the field of microelectronic devices. [ABSTRACT FROM AUTHOR]

MnO2 has advantages such as the simple and diverse preparation methods, low cost and high theoretical capacity, but its industrial application is affected by its poor conductivity and fast attenuation of cycle performance. In order to improve its conductivity, battery capacity and performance, MnO2/carbon nanofibers (MnO2/CNFs) are obtained by using electrospinning technology, and the electrochemical performance was confirmed by XRD, SEM, TEM. Confirmed by comparison, the 20% MnO2/CNFs exhibit superior and excellent long cycling performance with a reversible capacity of 835 mA h g−1 at 0.1 A g−1 after the 133th cycle and a high initial specific capacity of 1094 mA h g−1 at a current density of 0.1 A g−1. The MnO2/CNFs have notable specific capacities with a coulombic efficiency of 99.5%, which greatly improve the reaction rate. This can also be used as a flexible electrode material because of its good flexibility. Due to the fact that carbon has better electron/ion conductivity, it shows better kinetics. [ABSTRACT FROM AUTHOR]

Lithium-sulfur batteries have attracted significant attention due to their high theoretical capacity density (1675 mA h g− 1) and low production cost. However, under practical conditions, the low conductivity of sulfur, volume expansion, and shuttle effect of lithium polysulfide (LiPSs) still hinder the broad application of lithium-sulfur batteries. A self-assembled flexible electrode material (Nb2O5/PANI-cc@S) is designed and fabricated here. The core of Nb2O5 nanowire arrays is coated with a shell of PANI and assembled with carbon cloth (cc) as a new sulfur fluid collector. The composite exposes more active sites between sulfur and the catalytic medium to capture LiPSs. In addition, the extra free space between Nb2O5 nanowire arrays is conducive to the penetration of liquid electrolytes. Moreover, the shell structure of PANI on the electrode surface enhances the structural stability of the composite electrode material. It effectively inhibits the outward diffusion of polysulfide and the volume expansion during the cycle. Thanks to these synergies, the self-supporting Nb2O5/PANI-cc@S has a high specific capacity of 1265.7 mA h g− 1 at 0.1 C and retains an impressive 1112.2 mA h g− 1 capacity even after 100 cycles at 0.1 C. It shows great potential to promote the practical application of flexible lithium-sulfur batteries.Graphical Abstract: Lithium-sulfur batteries have attracted significant attention due to their high theoretical capacity density (1675 mA h g− 1) and low production cost. However, under practical conditions, the low conductivity of sulfur, volume expansion, and shuttle effect of lithium polysulfide (LiPSs) still hinder the broad application of lithium-sulfur batteries. A self-assembled flexible electrode material (Nb2O5/PANI-cc@S) is designed and fabricated here. The core of Nb2O5 nanowire arrays is coated with a shell of PANI and assembled with carbon cloth (cc) as a new sulfur fluid collector. The composite exposes more active sites between sulfur and the catalytic medium to capture LiPSs. In addition, the extra free space between Nb2O5 nanowire arrays is conducive to the penetration of liquid electrolytes. Moreover, the shell structure of PANI on the electrode surface enhances the structural stability of the composite electrode material. It effectively inhibits the outward diffusion of polysulfide and the volume expansion during the cycle. Thanks to these synergies, the self-supporting Nb2O5/PANI-cc@S has a high specific capacity of 1265.7 mA h g− 1 at 0.1 C and retains an impressive 1112.2 mA h g− 1 capacity even after 100 cycles at 0.1 C. It shows great potential to promote the practical application of flexible lithium-sulfur batteries. [ABSTRACT FROM AUTHOR]

RC bridge substructures exposed to chloride environments inevitably suffer from corrosion of reinforcement embodied in concrete. This deterioration issue leads to the loss of reinforcement areas and a reduction in seismic capacity of reinforced concrete (RC) bridge substructures. To quantify the effect of steel corrosion on seismic fragility estimates, this paper proposes an improved time-dependent seismic fragility framework by taking into account the increase in the corrosion rate after concrete cracking and the reduction in seismic capacity of RC bridge substructures during the service life. Additionally, an analytical method based on a back propagation artificial neural network (BP-ANN) is proposed to provide probabilistic capacity estimates of deteriorating RC substructures. A three-span T-shaped girder bridge is selected as a case study bridge to provide improved time-dependent seismic fragility estimates that consider uncertainties in the material properties, geometric parameters, deterioration process and ground motions. The obtained fragility curves show that there is a nonlinear increase in the exceedance probability of deteriorating RC bridge substructures for different damage states during the service life. In addition, time-dependent seismic fragility analysis shows that the cases of considering only the effect of an increase in seismic demand or the reduction in seismic capacity as well as neither of them may lead to a significant underestimation of the seismic vulnerability of deteriorating RC bridge substructures. [ABSTRACT FROM AUTHOR]