Arrays of nanostructure that are capable of broadband antireflection and light trapping properties are implemented in photovoltaic and photonic devices. However, most of the existing antireflection films have been hindered by a complicated fabricated method and structurally rigid. Here, we report a simple preparation method for self-erasable nanocone antireflection films using the surface replication method. Arrays of nanocone with sub-100 nm surface features could be replicated easily on the shape memory polyvinyl alcohol (PVA) film, and are erased by thermal stimulation. The reflectivity of self-erasable antireflection film can be switched from the 4.5% to 0.6% averaged over the visible spectral range by controlling the temperature below or above 80 °C. Theoretical simulations have been demonstrated. The unique smart film is expected to be used to further extend the application of smart optical windows and digital screens.

Multiframe PC box‐girder bridge with intermediate hinges is a kind of bridge having complex structural characters, which is very quintessential in California. In this study, a typical bridge was adopted to establish a nonlinear dynamic model through OpenSees platform. Intermediate hinge and inhibiting devices in it were elaborately simulated. Meanwhile, pushover analysis was used to reinstate a specimen of column test, which has the similar ratio of reinforcement to the typical bridge, and the hysteretic model parameters of the longitudinal steels inside columns were obtained. The damage indexes of column and hinge, which are primary components, under different limit states were acquired by moment‐curvature analysis. Taking into account the uncertainty, nonlinear time‐history analysis of the bridge was carried out through a suite of synthetic ground motions. Subsequently, a probabilistic seismic demand model was developed, and fragility curves were further focused on. According to fragility assessment, the conclusion shows that columns and hinge restrainers exhibit high fragility, and bridge system fragility is gradually determined by column fragility along with aggravating of the damage state. Unseating of girder can hardly occur at abutments and intermediate hinges. Moderate limit state could be exceeded in the positions of plug‐type concrete structures in intermediate hinges, which tends to create transverse and vertical cracks, furthermore causing reinforcements yield. It indicates that it would severely underestimate the seismic fragility of intermediate hinges without considering the elaborate simulation of hinges.

Due to the significant impedance mismatch between water and air, two types of pipeline silencers designed for the same target frequency with different filling materials often have significantly different thickness. This increases the difficulty in designing silencers for multiple pipelines with different filling materials in narrow spaces. The paper reports a metamaterial design paradigm based on a Helmholtz cavity for low-frequency sound absorption for both air pipelines and water-filled pipelines. An asymmetric absorption metamaterial with coupled Helmholtz resonators is proposed to reduce the impact of low-frequency noise in air pipelines. By coupling the absorption mode and reflection mode, the asymmetric absorption metamaterial with a thickness of 71 mm achieves 95.6% absorption at 403 Hz. The tunable absorbing performance in broadband is confirmed by a finite element simulation. Additionally, a composite metamaterial constructed with HRs associated with a rubber layer is proposed for low-frequency broadband sound absorption in water-filled pipelines. An average absorptance of above 0.8 is achieved over the range of 380–508 Hz by coupling four basic composite metamaterial units with a thickness of 31.5 mm. The proposed design paradigm can reduce the complexity of designing multiple pipelines silencers with different filling materials because the muffler should have similar thickness in the same paradigm.