Angle-robust and tunable mid-infrared absorption in a Ge grating/SrTiO/VO hybrid metastructure on a metallic substrate.

We propose a dynamically tunable and angle-robust mid-infrared (mid-IR) absorber based on a hybrid metastructure composed of a top-layer Ge grating, an ultrathin SrTiO polar dielectric layer, a thermochromic VO film, and a metallic substrate. The optical response of the system is modeled using rigorous coupled-wave analysis (RCWA), revealing broadband and high-efficiency absorption across a wide range of incident angles (0°-80°) under transverse-magnetic (TM) polarization. The absorption behavior is governed by the interplay of multiple resonant mechanisms, including guided-mode resonance (GMR) in the Ge grating, phonon-polariton (PhP) excitation in the SrTiO layer, and cavity-like modes facilitated by the insulating VO.

Laser-induced breakdown spectroscopy for imaging and distribution analysis of heavy metal elements in soil.

The accumulation of heavy metals (HMs) in soil due to industrial activities and sewage irrigation poses serious environmental and health risks. In this study, soil samples contaminated with copper (Cu), chromium (Cr), and lead (Pb) were selected for investigation. An experimental system based on laser-induced breakdown spectroscopy (LIBS) was developed to perform the elemental analysis and mapping of the contaminated soils.

Design and Hysteresis Compensation of Novel Resistive Angle Sensor Based on Rotary Potentiometer.

Resistive angle sensors are widely used due to their simple signal conditioning circuits and high cost-effectiveness. This paper presents a resistive angle sensor based on a rotary potentiometer, designed to offer a measurement range of 180° for low-cost angle measurement in industrial automation and electromagnetic interference (EMI)-sensitive applications. The sensor features a specially designed signal conditioning circuit and mechanical housing.

Dynamically tunable strong coupling insulator-metal phase transition in VO coupled to mid-infrared SrTiO phonons.

Dynamically tunable strong light-matter coupling in the mid-infrared (MIR) regime holds significant promise for next-generation photonic and thermal devices, especially in the long-wave infrared (LWIR) range of 19-23 μm, where vibrational and thermal signatures are most prominent. In this work, we demonstrate strong coupling between the phase-transition-tunable Fabry-Pérot (FP) cavity modes of vanadium dioxide (VO) and the phonon polaritons (PhPs) of strontium titanate (SrTiO), a polar dielectric with prominent optical phonon resonances in the LWIR region. The insulator-to-metal transition (IMT) of VO enables dynamic tuning of the coupling strength and mode hybridization.

Dual Mode Fusion Based on Rock Images and Laser-Induced Breakdown Spectroscopy to Improve the Accuracy of Discriminant Analysis.

Rocks are an extremely important and indispensable part of the Earth's crust, with wide applications in various fields such as geology, environmental monitoring, and industry. Traditional methods often rely on a single analytical technique or visual inspection, but this may not achieve the accuracy required for thorough classification. Laser-induced breakdown spectroscopy (LIBS) technology mainly provides information on the composition and content of rock elements, while images can provide appearance information such as color and texture.

Development of a solar radiation measuring instrument for building energy management system.

Excellent architectural design, energy-efficient control systems, and smart home technologies need to take into account the influence of solar radiation. Therefore, there is a necessity for high-precision measurement of solar radiation. However, existing solar radiation instruments are susceptible to environmental factors such as wind speed, air temperature, and air density, resulting in significant measurement errors.

A novel system for precise identification and explainability analysis based on multimodal learning combining laser-induced breakdown spectroscopy and laser-induced plasma acoustic signals.

This study presents an innovative approach to identify copper types using Laser-Induced Breakdown Spectroscopy (LIBS) in conjunction with Laser-Induced Plasma Acoustic (LIPA) signals. Traditionally overlooked, plasma acoustic signals can indeed provide valuable insights into plasma characteristics essential for copper identification. This study pioneers a cross-modal learning technique, integrating LIBS and LIPA signals, and employs a Support Vector Machine (SVM) for classification.

Advanced Characterization of Industrial Smoke: Particle Composition and Size Analysis with Single Particle Aerosol Mass Spectrometry and Optimized Machine Learning.

With the acceleration of industrialization, industrial smoke particles containing complex chemical compositions and varying particle sizes pose a serious threat to the environment and human health. As a powerful tool for aerosol measurement, mass spectrometry can effectively analyze particulate matter. However, due to the high dimensionality and complexity of mass spectrometry data, research on the relationship between particle size and composition remains very limited.

Advanced recycling and identification system for discarded capacitors utilizing laser-induced breakdown spectroscopy technology.

In the modern electronics industry, with the rapid development of technology and the quick turnover of electronic products, the production of electronic waste (e-waste) has also dramatically increased. Among these, discarded capacitors are a significant component of e-waste. These old capacitors not only contain harmful chemicals but are also rich in economically recoverable precious metals like Nb and Ag.

Development of an atmospheric boundary layer detection system based on a rotary-wing unmanned aerial vehicle.

To enhance meteorological detection methods, an atmospheric boundary layer detection system based on a rotary-wing unmanned aerial vehicle (UAV) was proposed. Computational fluid dynamics (CFD) was employed to model the surrounding airflow distribution during UAV hovering, thereby determining the optimal positions for sensor installation. A novel radiation shield was designed for the temperature sensor, offering both excellent radiation shielding and superior ventilation.

Development of Highly Sensitive and Thermostable Microelectromechanical System Pressure Sensor Based on Array-Type Aluminum-Silicon Hybrid Structures.

In order to meet the better performance requirements of pressure detection, a microelectromechanical system (MEMS) piezoresistive pressure sensor utilizing an array-type aluminum-silicon hybrid structure with high sensitivity and low temperature drift is designed, fabricated, and characterized. Each element of the 3 × 3 sensor array has one stress-sensitive aluminum-silicon hybrid structure on the strain membrane for measuring pressure and another temperature-dependent structure outside the strain membrane for measuring temperature and temperature drift compensation. Finite-element numerical simulation has been adopted to verify that the array-type pressure sensor has an enhanced piezoresistive effect and high sensitivity, and then this sensor is fabricated based on the standard MEMS process.

Weyl semimetal/dielectric/Weyl semimetal stack for highly circularly polarized thermal radiation.

Highly circularly polarized (CP) infrared thermal radiation is greatly in demand because of its significant potential in mid-infrared (mid-IR) applications. To exploit the magnitude and quality factor of circular dichroism (CD) simultaneously, a lithography-free platform consisting of a Weyl semimetal (WSM)/dielectric (Ge)/WSM stack sitting on a metallic substrate (Mo) is proposed. A chiral response and varying CD values from -1 to 0.

Zeroth-order gradient tracking for decentralized learning with privacy guarantees.

This paper proposes a differential privacy decentralized zeroth-order gradient tracking optimization (DP-DZOGT) algorithm for solving optimization problems of decentralized systems, where the gradient information of the function is unknown. To address the challenge of unknown gradient information, a one-point zeroth-order gradient estimator (OPZOGE) is constructed, which can estimate the gradient based on the function value and guide the update of decision variables. Additionally, to prevent privacy leakage of agents, random noise is introduced into both the state and the gradient of the agents, which effectively enhances the level of privacy protection.

Real-time in situ detection of petroleum hydrocarbon pollution in soils via a novel optical methodology.

Petroleum hydrocarbon (PHC) contamination in soils is considered one of the most serious problems currently, of which the detection and identification is a fairly significant but challenging work. Conventional methods to do such work usually need complex sample pretreatment, consume much time and fail to do the in-situ detection. This paper set out to create a novel systematic methodology to realize the goals accurately and efficiently.

Design of a hemispherical shell shaped natural ventilation temperature observation instrument.

Atmospheric temperature is fundamental information for various industries, such as production, life, and scientific research. The temperature error induced by the solar rays can reach 1 °C or even higher. A hemispherical shell-shaped atmospheric temperature measuring instrument that can reduce heat pollution and increase air velocity was designed.

Rapid classification of whole milk powder and skimmed milk powder by laser-induced breakdown spectroscopy combined with feature processing method and logistic regression.

Whole milk powder and skimmed milk powder are suitable for different groups of people due to their differences in composition. Therefore, a rapid classification method for whole milk powder and skimmed milk powder is urgently needed. In this paper, a novel strategy based on laser-induced breakdown spectroscopy (LIBS) and feature processing methods combined with logistic regression (LR) was constructed for the classification of milk powder.

Weyl semimetal mediated epsilon-near-zero hybrid polaritons and the induced nonreciprocal radiation.

Polaritonic excitation and management in ultra-thin polar crystals has recently received significant attention and holds new promise for epsilon-near-zero (ENZ) modes. However, manipulation of the ENZ mode anisotropic magneto-optic (MO) material remains elusive. Herein, we provide an effective strategy for constructing an ENZ polar thin film with dependence on Weyl semimetals (WSM).

Energy value measurement of milk powder using laser-induced breakdown spectroscopy (LIBS) combined with long short-term memory (LSTM).

Milk powder can provide the necessary nutrients for the growth of infants, and the level of its energy value is an important factor in the measurement of its nutritional value. Therefore, the measurement of the energy value in milk powder is of great significance for the nutritional health of infants. In this study, samples of 32 different brands of milk powder were selected for spectral analysis, and laser-induced breakdown spectroscopy (LIBS) combined with deep belief network (DBN), back propagation (BP) neural network, and long short-term memory (LSTM) models was used to achieve quantitative analysis of the energy value of the milk powder.

Development of a flat conical chamber-based non-dispersive infrared CO2 gas sensor with temperature compensation.

In order to accurately monitor CO2 concentration based on the non-dispersive infrared technique, a novel flat conical chamber CO2 gas sensor is proposed and investigated by simulation analysis and experimental verification. First, the optical design software and computational fluid dynamics method are utilized to theoretically investigate the relationship between the energy distribution, absorption efficiency of infrared radiation, and chamber size. The simulation results show that the chamber length has an optimal value of 8 cm when the cone angle is 5° and the diameter of the detection surface is 1 cm, which makes infrared absorption efficiency optimal.

Magnetical Manipulation of Hyperbolic Phonon Polaritons in Twisted Double-Layers of Molybdenum Trioxide.

Controlling the twist angle between double stacked van der Waals (vdW) crystals holds great promise for nanoscale light compression and manipulation in the mid-infrared (MIR) range. A lithography-free geometry has been proposed to mediate the coupling of phonon polaritons (PhPs) in double-layers of vdW α-MoO3. The anisotropic hyperbolic phonon polaritons (AHPhPs) are further hybridized by the anisotropic substrate environment of magneto-optic indium arsenide (InAs).

Development of a surface atmosphere temperature observation instrument.

To minimize the impact of various radiations on atmospheric temperature observation, a new natural ventilation temperature observation instrument is designed in this paper. First of all, the temperature measuring instrument model is constructed using the means of computational fluid dynamics. Then, the radiation error of the device is quantified in different environmental conditions.

Quantitative analysis of fertilizer using laser-induced breakdown spectroscopy combined with random forest algorithm.

Chemical fertilizers are important for effectively improving soil fertility, promoting crop growth, and increasing grain yield. Therefore, methods that can quickly and accurately measure the amount of fertilizer in the soil should be developed. In this study, 20 groups of soil samples were analyzed using laser-induced breakdown spectroscopy, and partial least squares (PLS) and random forest (RF) models were established.

Ultra-Thin and Lithography-Free Transmissive Color Filter Based on Doped Indium Gallium Zinc Oxide with High Performance.

A kind of ultra-thin transmissive color filter based on a metal-semiconductor-metal (MSM) structure is proposed. The displayed color can cover the entire visible range and switches after H treatment. An indium gallium zinc oxide (IGZO) semiconductor was employed, as the concentration of charge carriers can be controlled to adjust the refractive index and achieve certain colors.

Excitation of Hybrid Waveguide-Bloch Surface States with BiSe Plasmonic Material in the Near-Infrared Range.

Bloch surface waves (BSWs) with BiSe in a composite structure consisting of a coupling prism, distributed Bragg reflector (DBR) and cavity layer have been demonstrated. The design relies on the confinement of surface waves that originates from the coupling between the defective layer of plasmonic material (BiSe) and DBR. The presence of the cavity layer modifies the local effective refractive index, enabling direct manipulation of the BSWs.

Maximum Power Point Tracking Control for Non-Gaussian Wind Energy Conversion System by Using Survival Information Potential.

In this paper, a wind energy conversion system is studied to improve the conversion efficiency and maximize power output. Firstly, a nonlinear state space model is established with respect to shaft current, turbine rotational speed and power output in the wind energy conversion system. As the wind velocity can be descried as a non-Gaussian variable on the system model, the survival information potential is adopted to measure the uncertainty of the stochastic tracking error between the actual wind turbine rotation speed and the reference one.