This paper presents a low-scattering and dual-polarized reconfigurable reflectarray antenna (RRA). The whole comprises an active coding metasurface cascaded with absorptive above. Upon integration p-i-n diodes, the unit cell achieves reflected phase near 180° difference, leading to high gain ±60° beam scan performance. In addition, multidrive modes of diodes can realize absorption or scattering cancellation effects in operating band RRA. out-of-band reduction performance is obtained owing...

High-water content dredged sludge from waterways, with potential for sustainable use as high-performance fillers, was effectively treated using the vacuum preloading-flocculation-solidification combined method (denoted VP-FSCM). This study investigated effect of flocculant and curing agent dosages on solidification initially poor mechanical properties. Ground granulated blast-furnace slag (GGBS) ordinary Portland cement (OPC) were selected composite agents, while anionic polyacrylamide...

At present, many countries in the world have been gradually building LEO satellite constellation. satellite, with its characteristics of small delay and large coverage, provides a possible solution for full coverage ground communication network. This paper implementation IOT system analyzes development status puts forward architecture characteristics, so as to provide solutions research directions in-depth study satellite.

Abstract Origami metasurfaces have emerged as a versatile platform for dynamically manipulating electromagnetic waves due to their numerous advantages, including cost‐effectiveness, lightweight nature, and diverse structural transformations. They are particularly well‐suited reconfigurable chiroptical responses that can find utility in various applications. However, current research has primarily focused on modulating spectral properties like optical chirality resonant frequencies, which may...

Abstract A broadband optically transparent metasurface microwave absorber (MMA) is designed and experimentally studied. The MMA made of two indium tin oxide (ITO) resistive films deposited on polyethylene terephthalate substrates respectively, between which sandwiched a single air spacer. top ITO film etched with periodic interdigital patterns in rotational symmetry, while the bottom an integrated sheet low resistance working as backplane. By carefully optimizing functional structures...

Abstract Wideband microwave absorbers hold significant importance in both civilian and military fields. In this paper, a lightweight ultra‐wideband metasurface absorber that covers frequency range from the ultrahigh‐frequency band to Ku is presented. The consists of three layers periodically arranged fourfold rotationally symmetric indium tin oxide (ITO) patterned structures reflective surface at bottom layer separated by polymethacrylimide (PMI) spacers. Such design enables achieve...

In this letter, we present a frequency-selective radome capable of providing an ultrawide transmission and low-scattering band for arbitrarily polarized waves. The proposed comprises two lossy layers bandpass frequency selective surface. are combined using miniaturized 2.5-D configurations, which realize the absorption effect above L-band. FSS integrates diffusion function on upper side passband. absorbs in low-frequency band, transmits middle-frequency exhibits hybrid scattering...

A next-generation video coding standard High Efficiency Video Coding (HEVC) provides higher quality and lower compression bit rate but leads to very high encoding complexity, especially in the quad-tree-based tree unit partitioning process. To reduce computational complexity of HEVC, this paper, we propose an adaptive quad-tree depth range prediction mechanism. First, proposed mechanism defines similar region flag distinguish between non-similar region. Then, two algorithms, algorithm...

This paper investigates the hybrid beamforming for multi-user millimeter wave (mmWave) multiple-input-multiple-output (MIMO) systems under sub-connected architecture where each antenna is only connected to a unique radio frequency (RF) chain. Based on perfect knowledge of channel state information (CSI), analog combiner user achieved by using singular value decomposition (SVD), and digital precoder minimizing Frobenius norm matrix difference between unconstrained products RF baseband...

We present MOFI, Manifold OF Images, a new vision foundation model designed to learn image representations from noisy entity annotated images. MOFI differs previous work in two key aspects: (i) pre-training data, and (ii) training recipe. Regarding we introduce approach automatically assign labels images image-text pairs. Our involves employing named recognition extract entities the alt-text, then using CLIP select correct as of paired image. It's simple, cost-effective method that can scale...

Objective To establish an infrared spectroscopic method for the rapid qualitative and quantitative analysis of caffeine sodium benzoate in Annaka samples. Methods Qualitative modeling samples were prepared by mixing high-purity benzoate. The characteristic absorption peaks determined analyzing spectra mixed model was established partial least squares （PLS）. Results By 17 （the purity ranges from 10% to 80%）, be 1 698, 650, 237, 972, 743, 609 cm-1. 596, 548, 406, 845, 708 679 When detection...

Abstract Reconfigurable metasurfaces have gained significant attention due to their flexible capabilities in manipulating electromagnetic (EM) waves. In particular, amplitude and phase both play crucial roles the wavefront regulation. However, most reported reconfigurable focus either on amplitude‐only or phase‐only control within a single polarization, thereby limiting functionalities applications. this work, design approach of dual‐polarization independently joint amplitude‐phase...

Active metasurfaces with dynamically reconfigurable functionalities are highly demanded in various practical applications. Here, we propose a wideband low-scattering metasurface that can realize an in-band transparent window by altering the operation states of PIN diodes loaded on structures. The is composed band-pass frequency selective surface (FSS) sandwiched between two polarization conversion (PCMs). integrated into FSS to switch window, while checkerboard configuration applied PCMs for...

In this paper, a novel multi-layer frequency-selective rasorber (FSR) with wide low-backscattering frequency band is proposed, which realized through an absorption at low and transmission high for arbitrary polarization. The FSR composed of three structures. bottom layer surface (FSS), achieves higher-order in the X-band also serves as metallic ground plate absorbers. Two circuit analog absorbers are designed to absorb electromagnetic (EM) wave energy different frequencies by using meander...

In this article, a transmit-reflect-array antenna (TRA) is present to realize asymmetric bidirectional beams based on the non-interleaved metasurface. The reflected and transmitted work in same frequency polarization. meta-atom employed as TRA's array, can independently control phases amplitudes transmission reflection channels. TRA performs 3-dB gain difference between beams. simulated 2 dB bandwidths are 30.4% of beam 18.9% beam. Moreover, maximum aperture efficiency 44.35%.

In this paper, we present a frequency-selective rasorber (FSR) which achieves wide low-scattering fequency band with transmission window in the middle for arbitrary polarization incident polarizations. The structure is composed of multilayer bandpass FSS diffuse scattering and two absorbing metasurfaces. samples are fabricated employing printed circuit board (PCB) technique. Two foam layers filled into three PCB as supporting structure, whose thickness properly chosen to realize good...