As an inherent degree of freedom, total angular momentum (TAM) photons consisting spin and orbital has inspired many advanced applications attracted much attention in recent years. Probing TAM tailoring beam's spectrum on demand are great significance for TAM-based scenarios. We propose both theoretically experimentally a processor enabling tunable manipulation. Such consists set quasi-symmetric units, each unit is composed couple diffraction optical elements fabricated through polymerized...

A circularly polarized (CP) patch array antenna is proposed for ultrawideband operation by introducing weak-coupling mechanism into feeding network, unit, and radiation structure, respectively. As an example, a wideband 2×2 consists of weakly coupled-line four-feed coupled four sequentially rotated symmetric hexagonal patches designed verification. Measured results show that the exhibits 10-dB impedance bandwidth 98% (2-5.92 GHz), 3-dB axial ratio 96.3% (2.15-6 gain variation 82.5%...

Besides a typical high-density plasma source, electrical explosion of conductors is also indispensable in switches, nanomaterial synthesis, shock-wave sources, etc. In this paper, an experimental study regarding dynamics wire explosions (μs-timescale) presented, with spatiotemporal resolved diagnostics. Pure Cu/Ni and Cu-Ni alloy were used compared. The usually has higher resistivity, resulting initial energy deposition (heating) rate. Abel inverse transformation indicated that the radiation...

Underwater shock waves generated by pulsed electrical discharges are an effective, economical, and environmentally friendly means of stimulating reservoirs, this technology has received much attention intensive research in the past few years. This paper reviews main results recent work on underwater wire explosion (UEWE) for reservoir stimulation. A platform is developed microsecond single-wire explosions water, diagnostics based a voltage probe, current coil, pressure photodiode,...

Abstract Gold nanoparticles (Au NPs) have a wide range of applications because their localized surface plasmon resonance properties. Femtosecond laser is considered to be an effective method for preparing Au NPs its characteristics ultrashort irradiation periods and ultrahigh intensities. In this study, novel proposed produce NP-attached substrate using the spatially temporally shaped femtosecond laser. Laser-induced periodic structures (LIPSS) are designed obtain optical field enhancement,...

Electrical explosion of wires (EEW) was carried out in an argon atmosphere for the preparation nanoparticles. Aluminium with 0.1 mm diameter and 13 cm length (low mass) 0.4 11 (high were used, which vaporization energy wire was, respectively, far below comparable to initial stored power-supply capacitors. A numerical model used study nanoparticle formation within exploding plasmas. The is based on a moment method modified according specific requirements EEW—rapid expansion high concentration...

Electrical explosion method as a powerful tool for one-step synthesizing metallic nanoparticles has raised widely interests. In this paper, experiments were performed with three metal wires, namely copper, tungsten and titanium who are the typical representation of non-refractory refractory metals. High-speed photography along electrophysical optical diagnostics applied to characterize electrical explosion. Accordingly, SEM TEM was used micro-morphology products. XRD detect phase...

Abstract Electrical explosion, characterized by ultrafast atomization and quenching rate (d T /d t ≈ 10 –10 12 K s –1 ) of the sample, is a unique approach for “one‐step” synthesis nanomaterials. Experiments are carried out with layered graphite Bi 2 Se 3 under action electrical explosion in confined reaction tube. High‐speed photography electrophysical diagnostics applied to characterize dynamic processes. SEM EDS used surface micro‐morphology products. The materials first exfoliated thin...

A stable and simple interferometric arrangement based on a Wollaston prism is designed to combine two helical beams into polarization vortex (PV). Different modes of are generated by spatial light modulator (SLM). Due the flexibility SLM, PVs with different kinds intensity distribution, such as Laguerre-Gaussian Bessel modes, generated.

This paper deals with an experimental study regarding the spatial–temporal evolution of single wire explosions in air and water at atmospheric pressure. Experiments were carried out a microsecond timescale pulsed current source under 500 J stored energy. The morphology exploding different discharge type, material, insulating coat, ambient medium was intensively observed via self-emission images. results revealed that plasma radiation explosion mainly contained two stages: initial intense...

Abstract A broadband circularly polarized (CP) printed monopole antenna which fed by coplanar waveguide (CPW) is proposed in the paper. The structure of novel includes a quarter circular disc radiating monopole, coupled patch, and bent L-shaped microstrip stub line. line used to widen impedance bandwidth generate horizontal component electromagnetic wave. adoption asymmetric ground with single-feed technology simultaneously achieve wide axial ratio (AR) bandwidth. parameters surface current...

Nanomaterials with unique structural and properties can be synthesized by rapid transition of the thermodynamic state. One promising method is through electrical explosion, which possesses ultrafast heating/quenching rates (dT/dt~109 K/s) exploding conductor. In this study, experiments were performed fine metallic wire in liquid nitrogen (liq N2, 77 K) under different applied voltages. For first time literature, physical image explosion dynamics liq N2 depicted using electro-physical...

Speed and precision are important for object detection algorithms. In this paper, a novel algorithm based on color histogram adaptive bandwidth mean shift is proposed. The capable of detecting objects rapidly precisely. It composed two stages: rough stage precise stage. At the stage, back projection thresholding applied to fast identification global localization. position, size orientation derived under framework. Experiments verify that able detect size, position general

The electrical explosion of a conductor driven by pulsed current can be used to simulate the effects explosions in laboratory, including resulting shock waves and bubble dynamics. A fine metallic wire also initiate discharge different media. This study shows images an exploding across air–water interface for first time literature. transient process was analyzed using high-speed backlit photography as well waveforms spectrum discharge. Streamer-like developed from triple-junction point within...

The physical image of breakdown dynamics inside striations is depicted. High-speed photography along with electrophysical and spectral diagnostics reveals three modes for plasma development in Cu wire explosion: current cutoff, initial (with quenching), main re-strike). growth spatial heterogeneity by electrothermal instability (ETI) provides a stratified structure before the breakdown. characteristic wavelength strata <100 μm thinner wires (d = 90/130 μm) but mm level thicker ones...