Development of non-noble metal catalysts with similar activity and stability to noble metals is significant importance in the conversion utilization clean energies.

Optical logic gates play important roles in all-optical circuits, which lie at the heart of next-generation optical computing technology. However, intrinsic contradiction between compactness and robustness hinders development this field. Here, we propose a simple design principle that can possess multiple-input-output states according to incident circular polarization direction based on metasurface doublet, enables controlled-NOT infrared region. Therefore, directional asymmetric...

In this paper, a dual-band perfect metamaterial absorber based on graphene is proposed in the terahertz region. The consists of two sizes disks and gold film separated by dielectric spacer unit cell. numerical results demonstrate that absorption can be achieved superposition specific peaks induced different disks. resonance frequency tuned via controlling conductivity achieve selectively tunability it tune each independently. And will not changed when small move along diagonal within range...

A dual-band filter using dual-capacitively loaded substrate integrated waveguide (SIW) cavities is proposed. Two conductive posts are embedded in the SIW cavity and capacitive effect generated by lowers first two resonant frequencies. Compared with unloaded of same size, frequency lowered 39% (from 4.12 to 2.51 GHz), second 20% 6.63 5.30 GHz). The also have capability tune frequencies independently, thus passbands can be flexibly controlled. proposed fabricated through a multilayer printed...

We demonstrate that multi-band coherent perfect absorption can be achieved at infrared frequencies by a metasurface in which four-sized columnar metal patches are separated dielectric layer unit cell. The bandwidth is enhanced three times compared with single-band while high absorbance maintained. polarization-independent and independently modulated each resonant frequency tuning the phase difference of two incident beams. Moreover, sensitive to radius patch, thus wide range obtained...

A compact triple-mode bandpass filter using a modified quarter-mode substrate integrated waveguide (QMSIW) cavity is presented. It realized by exploiting the first three resonant modes of QMSIW cavity. Specifically, dominant mode (TE101) shifted toward second (TE202) through perturbation induced metallized via-holes array. The frequency third (TE303) lowered TE202 owing to capacitive loading effect loaded circular conductive posts In this way, adjusting array and array, frequencies can be...

In this letter, a simple metasurface superstrate structure is proposed to reduce mutual coupling of both E-plane and H-plane coupled patch antennas. The consists periodic ring slots arranged on one side the substrate. can suppress surface wave partly change mode, which achieve isolation enhancement more than 40 dB at resonant frequency in E/H-plane edge-to-edge spacing between antenna elements 2 mm (0.023 λ0). prototypes arrays with metasurfaces are fabricated, experimental measurements...

Film capacitors have become key electronic components for electrical energy storage installations and high-power systems. Nonetheless, high-temperature high-electric-field environments would cause a surge of the loss, placing fundamental challenge film applied in harsh environments. Here, we constructed composite film, combining poly(ether sulfone) (PESU) with excellent thermal stability large-band-gap filler boron nitride nanosheets (BNNSs). The introduction BNNSs form deep/shallow traps...

The phase information of the echo is essential for inverse synthetic aperture radar (ISAR) imaging. Time-modulated metasurface (TMM) generates time-varying reflection that can modulate echo, thus enabling jamming ISAR imaging, which has great potential real applications. In practice, covering whole target with TMM difficult to achieve. Consequently, model a partially covered developed, extends fully more general and near-realistic case in this letter. Then, echoes each component are obtained...

Recently, a generalized likelihood ratio test (GLRT)-based multipixel target detector for hyperspectral imagery was proposed. With joint exploitation of the pixels occupied by interest, detection performance significantly improved. However, it still faces pixel selection problem in practice. In this paper, we address First, propose an adaptive method based on spectral similarity and spatial connectivity characteristics. Second, to collect spatially closest as training background so that...

Land cover classification using high-resolution Polarimetric Synthetic Aperture Radar (PolSAR) images obtained from satellites is a challenging task. While deep learning algorithms have been extensively studied for PolSAR image land classification, the performance severely constrained due to scarcity of labeled samples and limited domain acceptance models. Recently, emergence Segment Anything Model (SAM) based on vision transformer (VIT) model has brought about revolution in study specific...

In through-wall radar imaging, the multipath echoes caused by specular reflections at interior walls of an enclosed room will lead to ghosts in resulting image. The appear like true targets and therefore tend increase number false alarms. To solve this problem, a new ghost elimination method that removes from raw data is proposed study. With priori knowledge room, concise model first developed, based on which locations can be determined. Then, cancellation process consists two steps...

Compared with conventional mirrors that behave as isotropic electromagnetic (EM) reflectors, metamirrors composed of periodically aligned artificial meta-atoms exhibit increased degrees freedom for EM manipulations. However, the functionality most is fixed by design, and how to achieve active control still elusive. Here, we propose a multistate metamirror based on nonvolatile phase change material Ge2Sb2Te5 (GST) four distinct functionalities can be realized in infrared region exploiting...

In this paper, we investigate the feasibility of recognizing human motions by high resolution range information using a deep convolutional neural network (DCNN). Most existing schemes for radar-based motion classification exploited handcrafted features extracted from micro-doppler signature which may be weak or indistinctive in some motions. contrast to conventional methods, utilize classify is more robust than signature, especially when radial velocity not obvious, and it has better...

Abstract As the 2D counterpart of metamaterials, metasurfaces have drawn wide attentions in recent years due to their unique electromagnetic (EM) properties and subwavelength footprints. Although great efforts been made metasurface‐based full vectorial manipulation EM waves, realization multifunctional devices with high compactness is still challenging. Here, by employing mutual coupling between meta‐atoms induce spin‐selective magnetic resonance, a generalized design principle based on...

To improve osseointegration caused by the stress-shielding effect and inert nature of titanium-based alloys, in this work, we successfully constructed a strontium calcium phosphate (Sr-CaP) coating on three-dimensional (3D)-printed Ti6Al4V scaffolds to address issue. The energy-dispersive X-ray spectroscopy (EDS) diffraction (XRD) results indicated that coatings with without Sr doping mainly consisted CaHPO4. bonding strength met required ISO 13 779-4-2018 standard (≥15 MPa). vitro suggested...

The use of traditional compressed sensing methods in sparse aperture inverse synthetic radar (SA-ISAR) imaging suffers from high computational burdens and complicated formula derivations. To solve these problems, a complex-valued autoencoder (CVAE) architecture trained to efficiently obtain ISAR images incomplete echoes is proposed this letter. In addition, training set generated for network via self-supervised learning. Instead using multiple simulated scenes as set, range cells scene are...

The circularly polarized (CP) antennas with high gains have gained growing interest due to their significant advantages, but the existing works usually suffer from narrow bandwidths. In this work, a novel folded transmitarray antenna (CPFTA) inspired by characteristic mode analysis (CMA) method is proposed achieve broadband and high-gain CP radiation. CPFTA consists of top-layer multifunctional metasurface (MTS), bottom-layer polarization conversion (PCM) integrated linearly (LP) microstrip...

Guanidinium octahydrotriborate, with a melting point of <−10 °C, releases >10 wt% high purity hydrogen below 100 °C.

Reduced TiO₂(TiO_2−x) with a controllable reduction degree was synthesized, which can promote the catalytic hydrogenation of N-heterocycle as catalyst support.