This PDF file contains the front matter associated with SPIE Proceedings Volume 13183, including the Title Page, Copyright information, Table of Contents, and Conference Committee information.

A method by microwave digestion-plasma torch atomic emission spectrometry was developed for the determination of Cu, Cd, and Pb in Scutellaria indica. The samples of Scutellaria indica were digested by microwave. The heavy metal ion was enriched and extracted by cloud point extraction technology, which used 8-hydroxyquinoline as a chelating agent and Trion X-110 as an extractant. The determination of Cu, Cd, and Pb was analyzed by microwave digestion-plasma torch atomic emission spectrometry under optimal experimental conditions. The results show that the method provided curated measurements, good repeatability, good linear relationships, and high recoveries. A new method for the determination of heavy metals in traditional Chinese medicine and related products was established, which is environmentally friendly and convenient.

Melting salt was the method used in this work to produce mullite whiskers, employing industrial Si/SiC waste as a precursor. The goal of the study was to ascertain how temperature and the percentage of molten salt affected the development of mullite whiskers. Research results show that mullite whiskers are capable of being produced at temperatures of 900, 1000, and 1100 degrees Celsius with success. However, whiskers formed at 900℃ exhibit a significantly larger aspect ratio and a higher overall whisker content. Furthermore, mullite whiskers can be generated utilizing molten salt ratios of 56%, 66%, and 76%. Notably, whiskers produced with a molten salt ratio of 66% show a more uniform size distribution. This study offers valuable insights into mitigating environmental concerns associated with Si/SiC waste and presents a suitable method to prepare mullite whiskers.

Stray current corrosion has become one of the important reasons for corrosion failure of buried steel pipelines. In this paper, based on Comsol Multiphysics software, the influence of stray current on the corrosion of buried steel pipes under cathodic protection was simulated and analyzed, and the influence of leakage voltage, soil conductivity, pipeline buried depth and other factors on the cathodic protection potential was analyzed. The simulation results show that under the action of -1V cathodic protection, when the leakage voltage exceeds 10V, the interference degree of stray current is very strong, and the cathodic protection is likely to fail. Under cathodic protection, soil average current density was positively correlated with soil conductivity under a certain leakage voltage. With the increase of burial depth, the positive shift of pipeground potential decreases and gradually returns to the cathodic protection potential level. Therefore, the buried range greater than 1.5m is determined within the allowable range of field technology and economy, and the combination of cathodic protection can better prevent stray current corrosion interference. The research in this paper has important guiding significance for further understanding of stray current corrosion mechanism of buried steel pipelines.

Real-time monitoring of vibration status is essential to ensure the safe operation of major and precision mechanical equipment. However, vibration sensors based on traditional electromagnetic signal principles are often difficult to withstand harsh environments, and signal transmission can be unstable. In view of this, a non-contact magnetically coupled vibration sensor based on Fiber Bragg Grating (FBG) technology was developed. The sensor adopts a new design, combines the classic permanent magnet and diaphragm, and introduces a lever hinge structure, and proposes a sensing mechanism connected to the diaphragm and the lever hinge, and realizes the amplification effect of displacement through the lever action. The working principle of the sensor is described in detail, simulation analysis is carried out, and its performance is verified by experiments. After relevant experiments, it is obtained: (1) amplitude range: 1.0mm-2.2mm (2) sensitivity: −83pm/mm (3) linear fitting correlation coefficient: 0.97 (4) working frequency band: 0-3400Hz (5) resonant frequency: 3750Hz. Such sensors show great potential for fault detection and health monitoring in large-scale precision machinery.

Wavelength calibration is a crucial step in the practical application of the spectrometer. The relationship between wavelength and pixel position on the detector can be determined through characteristic spectral calibration. To apply the spectrometer to multi-channel spectral detection and other applications, we propose a method of multi-regions characteristic spectral calibration on a self-developed spectrometer by introducing a multi-core optical fiber. Experiments are carried out on the self-developed spectrometer with a spectral band of 537 nm ~ 600 nm and a resolution of 0.07 nm. The wavelength and pixel position are accurately matched through third-order polynomial fitting, with a fitting error of ±0.002 nm, improving the precision of the spectrometer in multi-channel measurement applications. At the same time, the spectral nonlinearity of the fitted polynomial is analyzed, and the results show that the spectral nonlinearity is about ±0.6 nm. Additionally, characteristic peaks of each region are fitted to calculate the resolution of the spectrometer. The results indicate that the spectrometer has a resolution of approximately 0.07 nm.

Optical efficiency is a crucial evaluation parameter for assessing the strengths and weaknesses of tower heliostat fields. Previous studies have indicated that optical efficiency is determined by factors such as shadow blocking rate, cosine efficiency, collector truncation efficiency, atmospheric transmission, and specular reflectance. This paper enhances the modeling of shadow blocking rate and collector truncation efficiency by abstracting real-world scenarios into mathematical problems involving trigonometric functions, coordinate systems, and normal vectors. For the shadow blocking rate, we establish a double shadow blocking model that considers both the inter-heliostat shadows and shadows between the absorption tower and heliostats. Regarding collector truncation efficiency, we develop a multi-base collector efficiency model that takes into account various combinations of intersecting sections between the cone beam's irradiation area on the collector surface and its absorption/reflection area. The inclusion of shadow blocking considerations along with categorizing intersections between beam illumination areas and collector absorption areas enables more universal, accurate, and practical calculations of optical efficiency. To evaluate our proposed method's performance, we calculate and compare the annual average optical efficiencies in a specific scenario using both our approach and traditional methods.

The enhanced broadband absorption and optimized impedance matching were of significant importance for achieving "thin, light, wide, and strong" in absorber materials. In this study, Fe_83.3Si₄B₇P₄Cu_0.7Co₁ amorphous alloy powders were prepared using vacuum air atomization method. The powders were mechanically crushed via high-energy ball milling, and the microstructure, morphology, and absorption properties of the materials were characterized. The results show that the loss mechanism of Fe_83.3Si₄B₇P₄Cu_0.7Co₁ amorphous alloy powders is primarily magnetic loss, including eddy current loss and natural resonance. The flattening of the powders not only increases anisotropy and optimizes impedance matching but also enhances the complex permittivity and permeability, endowing the material with excellent bandwidth effects and electromagnetic wave loss capability. The maximum effective absorption bandwidth (Δf_{RL<-10 dB}) of the sample ball-milled for 6 hours can reache 8.29 GHz (9.71 GHz ~ 18 GHz), with the minimum reflection loss(RL_min) at 13.2 GHz being -41.73 dB and a sample thickness of 2 mm. This indicates that the material has good absorbing performance and exceptional bandwidth capabilities in the mid to high-frequency range, covering part of the X-band and the entire Ku-band, offering greater flexibility and applicability in practical applications.

We prepare top-emitting 850 nm vertical-cavity surface-emitting laser (VCSEL) with a large oxide-aperture of 11 µm. The temperature-dependence of the output characteristics such as optical output power, threshold current, differential resistance and small-signal modulation bandwidth (f_3dB) are investigated. At room temperature, the VCSEL achieves a maximum optical output power of 12.62 mA and a maximum f_3dB of 18.5 GHz. With the increase of temperature, the thermal rollover current and the maximum optical output power both decrease. When the temperature rises to 55℃, the f_3dB of the device remains above 18 GHz. Finally, the modulation current efficiency factor (MCEF) at different temperatures is extracted by linear fitting of the f_3dB and the square root of the bias current above the threshold.

We proposed and fabricated an InGaN/GaN visible-light heterojunction photodetector with ultrahigh gain based on polarization self-depletion and quasi-superlattices (QSLs) induced photoconductive gain. In the detector, the polarization induced electric field is used to deplete the InGaN/GaN QSL absorber, serving as an internal photogate. On the other hand, the QSLs with the specific quantum barrier width can localize the photogenerated holes, thereby generating additional photoconductive gain. Benefitted from these two effects, the peak optical gain and responsivity of the photodetector reach 5.8×10⁴ and 1.9×10⁴ A/W respectively, under 5 V bias and 402 nm illumination. Meanwhile, the photodetectors indicate excellent weak-light detection capability, as well as a remarkable wavelength selectivity with 402 nm/500 nm rejection ratio surpassing 1×10⁴ .

This paper introduces an MPPT control methodology utilizing the IJAVA algorithm. This approach merges the traditional JAVA algorithm with a Levy flight strategy, enabling the algorithm to evade local optima and conduct a comprehensive global search for the optimal solution, so that the algorithm can ensure the convergence speed and give attention to the convergence accuracy, further accelerate the tracking speed by optimizing the initialization position of the population, and reduce the voltage and power oscillation in the tracking process by adding out-of-bounds processing mechanism. Based on the modeling and simulation outcomes, the MPPT control utilizing the IJAVA algorithm demonstrates the capability to effectively and precisely trace the optimum power point in the presence of partial shading, as evidenced by the results.

Photovoltaic power prediction is crucial for maintaining the safe, stable operation, and economic benefits of the power grid. However, the long short-term memory (LSTM) neural network faces limitations in parameter selection, affecting its effectiveness in photovoltaic power prediction. Additionally, photovoltaic power data exhibits volatility and non-stationarity, leading to inaccurate predictions. To address these issues, this paper proposes a coupled model named VMD-SSA-LSTM, which combines variational mode decomposition (VMD), sparrow search algorithm (SSA), and LSTM. The model initially employs VMD to decompose photovoltaic power data, reducing the impact of volatility and non-stationarity on prediction results. Subsequently, SSA is used to optimize LSTM parameters. Finally, the predicted values from each sequence are summed to obtain the photovoltaic power prediction. Simulation experiments demonstrate the model's high adaptability in short-term photovoltaic power prediction. Compared to the LSTM model, the VMD-SSA-LSTM model exhibits superior performance in prediction accuracy, stability, and robustness. Therefore, this model provides an effective solution to enhance the accuracy of photovoltaic power prediction, contributing to the safety, stability, and economic efficiency of power grid operation.

TiO₂ thin film UV detector was prepared by DC reactive magnetron sputtering method, and the response curves of the thin film detector under different bias voltages were measured. The relationship between the photocurrent of the detector and the wavelength of the irradiated light and the time response of the TiO₂ UV detector were studied.

Titanium alloy, with its excellent performance, has been widely used across various industries. However, its high friction factor and poor wear resistance limit further engineering applications. Laser cladding technology, known for its efficiency, rapidity, controllable heat input, and strong metallurgical bonding with the base material, has emerged as an effective method for surface modification of titanium alloys. The TiB-reinforced coatings were prepared by mixing pure Ti powder with h-BN powder on the Ti3Al2V surface of the substrate using laser cladding technology. The effects of laser scanning speeds (1.5mm/s, 3mm/s, 4.5mm/s, and 6mm/s) on the microstructure and microhardness of the fused cladding layer were experimentally investigated. The results indicate that the fused cladding layer exhibited a needle and rod-like structure, identified as the reinforced phase TiB. As the laser scanning speed increased, the size of the reinforced phase gradually decreased, while the number of particles increased, resulting in an uneven distribution. Surprisingly, the hardness of the fused cladding layer did not decrease with the increase in laser scanning speed; instead, it reached its highest value at a speed of 6mm/s. Furthermore, the hardness of the fused cladding layer surpassed that of the substrate. Overall, the optimal hardness was achieved at a laser scanning speed of 6mm/s.

The approach to large-scale PV has a lot of negative impacts on the distribution grid, such as the instability of the system voltage, the increase of harmonics etc. To solve the problem of voltage instability when PV is connected to power grid, this paper puts forward a strategy of using inverter for reactive power control, and makes full use of the reactive power regulation ability of the inverter Q (cos φ(U)) and Q(U). On the basis of the two control strategies, a weighted control method is proposed, which takes into account the control node voltage and improves the power factor of the system, and realizes the friendly grid-connected photovoltaic system.

The straight bandgap, high electron mobility, and good light absorption properties of gallium arsenide (GaAs) nanowires (NWs) make them great candidates for infrared photodetectors. In this study, we describe the synthesis of high-quality single-crystal GaAs NWs by solid-source chemical vapor deposition (SSCVD) and evaluate their photodetection performance. The prepared GaAs NWs exhibit excellent optoelectronic properties at a wavelength of 792 nm, with a photoresponsivity(R) of 3.65 A/W and a detectivity (D*) of 3.68×10¹¹ Jones, as well as excellent sensitivity and reproducibility. These findings emphasize the potential application of GaAs NWs in photodetector technology.

Cu₂ZnSnS₄ (CZTS) has attracted much attention because of its excellent properties. However, its development has been limited by antisite defects and low open-circuit voltage. Appropriate doping of metal cations can improve the above problems, but theoretical research on In-doping at the Sn site is relatively lacking. In this paper, we performed the hybrid functional theory of density functional theory (DFT) to study CZTS cells. The crystal structure parameters and electronic properties of Cu₂ZnSn_1-xIn_xS₄(x=0, 1/8, 1/2, 1) with different In doping concentrations were calculated using GGA-PBE functional. The results show that as the In-doping concentration increases, the volume of Cu₂ZnSn_1-xIn_xS₄ (x=0, 1/8, 1/2, 1) decreases, and the band gap increases, additionally, the conduction band of Cu₂ZnSn_1-xIn_xS₄ (x=0, 1/8, 1/2, 1) shifts to the high energy direction in turn. These findings indicate that In-doping can modulate the band gap of CZTS, thereby improve its electronic properties. Herein, in this study, a way is suggested to optimize the performance of CZTS cells.

This study aims to investigate the effect of electrode spacing on the performance of amorphous gallium oxide photodetectors. Firstly, we prepared a series of amorphous gallium oxide photodetector samples with electrode spacings of 80 µm, 100 µm, and 120 µm. Then, we tested the photoelectric performance of these samples. We found that the electrode spacing has a significant effect on the responsivity of the photodetectors. Due to the reduction of the carrier transmission distance, smaller electrode spacing can effectively improve the responsivity of the a-Ga₂O₃ photodetector, which reaches 0.096 A/W under 30 V, 255 nm illumination. This study provides a reference for the optimal design of the electrodes of amorphous Ga₂O₃ photodetectors.

For target recognition of sparse LiDAR scan data, this paper proposes a new method for aligning height data matrices based on rotation, length segmentation, and grid partitioning. Initially, the method involves rotating the matrix to achieve initial pose alignment between the height matrix of the target to be recognized and the template matrix. Subsequently, utilizing length segmentation, the orientation of the target is aligned, and the initial grid search position is determined. Finally, the method searches for the best alignment grid based on grid partitioning to achieve data matrix alignment and performs target recognition using a fuzzy recognition algorithm based on scanlines. Experimental results demonstrate that this method effectively aligns sparse target data with target template data, also enabling the recognition of typical targets such as cars, providing a valuable reference for target recognition of sparse LiDAR scan data.

With the rise of detection technology, ultraviolet detection has received attention in civilian, military and other fields, which has aroused great research interest. ZnO has great development prospects in the field of ultraviolet photodetectors due to its excellent physical, optical, and electrical properties. This article uses magnetron sputtering method to sputter high-quality ZnO thin films on inexpensive glass substrates. The morphology, crystal phase, and optical absorption of ZnO thin films were characterized by SEM, XRD, and UV/Visspectrophotometer. Metal-semiconductor-metal (MSM) structure Ti/ZnO ultraviolet photodetectors were prepared by vacuum evaporation. The effect of the number of interdigital electrodes on the performance of the photodetector was investigated by responsivity and I-V characteristic curves. The results show that the ZnO thin films prepared by magnetron sputtering are uniform and dense, have obvious ultraviolet absorption, and the performance of the photodetector is strongly dependent on the number of interdigital electrodes. When the working voltage is 10 V, the spectral response of the five pairs of interdigital electrodes is significantly enhanced (0.467 A/W). Therefore, this article provides certain reference values for the preparation and application of high-performance ZnO ultraviolet photodetectors.

Based on our previous work (Opt. Eng. 50 (7) 073402 (2011)), the diffusion equation in three step ion exchange processes is established, and the concentration ratio impact on the exchanged ion examines in detail. In addition, a theoretical model of the deviation of refractive index (RI) in the three-step ion exchange process is obtained and analyzed. The GRIN rod lens is prepared by three ion exchange processes, and the optical properties of the samples have been evaluated. The results show that the physical and chemical properties of GRIN rod lens in the three-step ion exchange process are better than those in the one-step and two-step ion exchange processes.

Perovskite materials have garnered significant attention in the photovoltaic sector, particularly in solar cell applications, primarily due to their exceptional physical and chemical properties. These include a high light absorption coefficient, tunable bandgap width, long charge carrier diffusion lengths, high carrier mobility, and the capability for solution processing. These attributes make perovskites a strong candidate for creating high-efficiency and low-cost photovoltaic devices. This article improves the light absorption capacity of Cs₃Bi₂I₉ single-crystal perovskites through optical simulation, utilizing the unique properties of photonic crystals to enhance the photovoltaic effect. The article concludes, based on simulation results, that the photonic crystal structure significantly impacts the absorption spectrum of Cs₃Bi₂I₉ thin film samples, offering benefits for solar cells, photodetectors, and related applications.

Using first-principles calculations, we investigated the formation energies of intrinsic point defects (V_Si and Si_int) in silicon crystals and the effects of defects on the electronic structure and optical properties. The results indicate that V_Si is more likely to form compared to Si_int. Both defects induce metallic behavior in silicon, with Si_int exhibiting stronger metallic properties. The impurity levels near the Fermi level are primarily contributed by Si 3p orbitals, revealing further control over the electronic behavior of silicon by defects. In terms of optical properties, both V_Si and Si_int significantly increase the dielectric function, optical absorption coefficient, and refractive index in the low-energy region, with Si_int exhibiting a greater increase than V_Si. However, in the intermediate energy region, both V_Si and Si_int reduce these properties. Additionally, VSi and Siint expand the optical response range of silicon, enhancing its absorption capabilities for infrared and visible light.

To prevent high-power fiber lasers from damaging the end surface of double-clad fibers, a fiber end-cap suitable for F-P filter structure was designed and developed. A fiber fusion splicer using CO₂ laser was utilized to splice the double-clad fiber and the fiber end-cap, and the related splicing techniques and methods were studied. The experimental results showed that by combining a self-made F-P filter with high-reflection and high-transmission spherical fiber end-caps, a continuous 2-micron narrow linewidth tunable laser output power of 75.4W was achieved, with a 3dB spectral linewidth of 0.12nm. The slope efficiency of the thulium-doped double-clad tunable fiber laser was 62.8% with the beam quality of 𝑀²_x = 1.247 and 𝑀²_x = 1.244 with a spliced fiber end-cap. The laser output beam quality did not change with the insertion of the F-P filter and fiber end-caps. This structure effectively reduced the power density at the fiber end face, increased the damage threshold, and did not affect the slope efficiency and beam quality, providing a theoretical and experimental basis for further improving the laser output characteristics.

Microplastic (MP) pollution presents a significant challenge to environmental protection and requires rapid detection and classification methods. We utilize machine learning methods coupled with fluorescence spectroscopy detection to improve the accuracy of MP detection and classification. To comprehensively explore MP classification, Principal Component Analysis (PCA) and PCA-SVM methods are used to analyze 2400 spectral data samples of six types of MPs. Each MP category is divided into a training set comprising 200 spectra and a test set containing 200 spectra to ensure robust evaluation. The initial SVM model achieves 100% classification accuracy for the test set, the associated computational burden is significant, with a training time of 42.14 seconds and a prediction time of 8.23 seconds. To enhance efficiency, we integrate the PCA algorithm, which reduces feature dimensionality without compromising accuracy. The integration of PCA significantly reduces training time to 9.46 seconds and prediction time to 0.05 seconds while maintaining a 100% classification accuracy rate. These results highlight the efficacy of our methodology in efficiently classifying MPs. Combining machine learning and fluorescence spectroscopy, our research provides a promising solution to the pressing challenge of monitoring MP contamination.

Terahertz (THz) waves are electromagnetic waves in the frequency range of 0.1 to 10 THz (wavelength of 3000 to 30μm). At present, terahertz technology is widely used in security inspection, temperature sensors, biosensors and other fields. Ceramic coating has the characteristics of high hardness, high wear resistance, high corrosion resistance, etc., and is widely used in many field. However, the damage of the ceramic coating will affect the protective performance of the coating and may even cause damage to the equipment. In this study, the thickness and erosion damage of ceramic coating are measured by terahertz technology. The results show that the terahertz detection technology can effectively detect the coating thickness and erosion damage.

Taking the failure of a 220 kV high-voltage cable intermediate joint as an example, this article analyzes the aging and failure of joints with epoxy resin as the insulating medium. Through testing the insulating structure, physical and chemical properties, and electrical performance of epoxy joints, it explores the impact of using epoxy resin as the insulating medium on the operation of cable joints. The analysis suggests that epoxy resin as the insulating medium of cable joints is prone to microcracks between the production process and the aluminum electrode interface, which accelerates the aging of epoxy materials under the action of electric field in later operation, increasing the risk of fault tripping.

A optical design of confocal scanning laser ophthalmoscope based on Chinese eye model is presented, which is featured by using a Chinese eye model. Firstly, a Chinese eye model, which is obtained by reverse building from Chinese population, is adopted as eye model. Secondly, a famous optical design architecture of confocal scanning laser ophthalmoscope is selected to build our design based on the Chinese eye model. In our design, the illumination light path, the retina imaging light path, and the corneal reflection light path are all implemented. The simulation show that our design has high resolution.

In the paper, a kind of cavity copper sulfide (CuS)uniform nano powders of perfect octahedron morphology, were synthesized by some typical ordinary processes, such as co-precipitation, reduction, vulcanization and etching, firstly. Then the powders were characterized by X-ray, SEM and BET respectively, for the analysis of CuS crystal structure and morphology. Testing results also confirmed that the obtained hollow nano copper sulfide powders possess high purity crystal structure, uniform microscopic morphology, as well as high specific surface area. Further, electromagnetic shielding capability of the CuS powders were checked by microwave vector network analyzer. The results indicated that the imaginary part of the complex permittivity of the powders locates in the range of 15-60, as were doped of 25%. Accordingly, the CuS powders possess strong infrared light absorption capacity, based on the theory of “the imaginary part is larger and the material has stronger absorption of light”. Further, as the thickness of the CuS powders smog riches 2mm, the electromagnetic wave attenuation may reach 60dB, and the powders smog will exhibit much better electromagnetic shielding performance. In summary, hollow octahedron copper sulfide powder of uniform morphology properties, with excellent electromagnetic shielding capabilities, were strategically synthesized by low-cost. The obtained powders are expected to be widely applied and used for electromagnetic shielding to against electronic reconnaissance, which provide a best model for exploring new electromagnetic shielding materials, also will promote the the progress of the related national defense abilities.

The Modular Artillery Charge System (MACS) is a key charge structure used in large-caliber howitzers. To investigate the combustion characteristics in the chamber of the two-modular charge, a combustion simulation experiment was conducted using the MACS combustion experiment platform. A two-dimensional, axisymmetric, two-phase flow interior ballistic model of the modular charge was established based on the charging structure of the two-modular charge. The ignition process of the two-modular charging chamber was numerically simulated using the high-order precision Monotonic Upstream-centered Scheme for Conservation Laws. The calculated results were compared to experimental results, yielding an average error of 2.84% and a peak error of just 2.17%. These findings indicate that the mathematical model and calculation method accurately describe the combustion process of the two-modular charge chamber. Additionally, the results demonstrate that the modular cartridge has a limited impact on the dispersion of powder particles, allowing for more complete powder burn. The temperature field diffuses radially and axially from the ignition hole, with an obvious gradient distribution at the edge of the temperature field. The pressure inside the chamber increases rapidly during combustion, peaking near the end of the burning phase and gradually decreasing afterwards. These simulation results provide valuable insights into the combustion characteristics of the two-modular charge chamber, aiding in the optimization of large-caliber howitzer designs and enhancing their performance.

Aiming at the problems of short distance, low communication rate, large loss and weak anti electromagnetic interference ability of carbon monoxide sensor in RS485 bus communication transmission, the circuits of sensor microprocessor, power supply module, photoelectric conversion module, display and audible and visual alarm are studied. A carbon monoxide sensor based on optical fiber signal transmission is designed by using single-mode optical transceiver module, The sensor equipment and the superior monitoring substation conduct high-speed data signal interaction through optical fiber to ensure the stability, timeliness and reliability of data transmission, which meets the application requirements of intelligent development of mining sensors.

Nowadays, the medical community lacks a tool on imaging the cerebral hemorrhage process in real time in order to rapidly analyze the dynamic process in cerebral hemorrhage. Against this background, this study proposes a light-sheet fluorescence microscopy imaging technique based on a tilted cylindrical lens. It introduces a difference through the lens to approach the cubic modulation required for Airy's light-sheet microscopy, which can utilize the diffraction-free and self-healing properties of Airy's beam. Meanwhile, it dramatically improves the effective field of view (FOV) on the basis of ensuring axial resolution, and also makes the whole imaging system more compact and less costly. According to the experimental results, this technique can effectively realize the real-time vivo imaging of zebrafish embryonic brain hemorrhage process, and can complete the real-time analysis of the whole process of blood vessel rupture, and collect the real-time information of the brain hemorrhage process with high temporal resolution. This study can focus on the dynamic process of cerebral hemorrhage, which is more advantageous than the traditional method that can only analyze the results. Moreover, this study can realize rapid 3D visualization and analysis of imaging data without processing the original imaging data, which greatly improves the operation efficiency.

In this paper, a cerebral blood oxygen signal acquisition method based on full-area near-infrared spectroscopy (650-1050nm) is designed. The incident light is emitted by halogen light source, and the outgoing light is received by the near-infrared spectrometer. A head-mounted near-infrared cerebral blood oxygen signal acquisition device is formed, and the feasibility of using near-infrared spectroscopy to collect cerebral blood oxygen signals is preliminatively verified. It can provide a new data set for the subsequent calculation of cerebral blood oxygen content.

In this paper, the influence of the spectrometer integration time on the collected signal is studied. By studying the relationship between the response time and the average response value in some wavelength range (650-1050nm), it can be seen that the response time and the average response value are in a positive proportional relationship. The results show that within a certain integration time (0.1-1s), the spectrometer integration time has little influence on the repeatability of the signal collected by the spectrometer, but when the integration time is greater than 1s, the longer the integration time, the worse the repeatability of the signal collected by the spectrometer.

In this letter, a multifunctional and reconfigurable radome has been designed based on active frequency selective surface (AFSS) and coding metamaterials. The proposed design comprises two periodic layers separated by an air spacer. By changing the bias voltage applied to the PIN diodes on the bottom layer, the radome can switch between perfect reflection and transmission. In the case of total reflection, the reflected waves can be further manipulated programmatically by changing the digital coding sequences of the top layer. The simulation results demonstrate the validity of our design.

We develop an ultra-thin cable diameter fiber hydrophone for large-scale arrays using chirped grating array fiber with coated sensitization, which has a diameter of 5 mm and a sensitivity of −148 dB (re 1 rad/ μPa) on the average and can be applied to towed arrays of Unmanned Underwater Vehicle.

In order to promote the application of artificial intelligence in multiple fields, a domestic intelligent acceleration module based on the Iluvatar CoreX MR100 chip was designed. The hardware design and software adaptation method of the AI module were introduced, and the performance of the acceleration module was tested. The test results showed that the acceleration module can be well compatible with CUDA. This acceleration module is capable of running common neural network models and is compatible with most applications developed on imported graphics cards. The localization rate of electronic components has reached over 90%, making it a good implementation solution for intelligent acceleration modules.

In order to more conveniently and clearly analyze the optical model property of the resonator, the logic relationship between the propagation circle and transformation circle of the dual-wavelength laser resonator and the focal length and dynamic stability of the thermal lens of the gain medium is established with propagation circle analysis method. A quasi-three-level thermal stable cavity containing a single thermal disturbance center is established. According σ circle and π circle tangent requirements, the relationship between the fundamental mode spot size and the curvature radius of M1 mirror in the gain medium of quasi-three-level laser is analyzed. By analyzing the thermal stability cavity of the quasi-three-level laser cavity with single thermal disturbance center, the position and f_t2 value of the plane mirror M2 (the focal length value of the F_t2 lens) are determined.

Bimetallic structures are used in a wide range of applications and play a key role in equipment such as aerospace and thermostats. However, the abundance of internal and external excitations and nonlinearities in bimetallic structures, as well as the complexity and variability of their operating environments, make their dynamics more complex to analyse compared to other systems. In addition, the interactions between the components that make up the bimetallic structure, wear and tear, and the operating environment will lead to uncertainties in the internal and external excitations and system parameters of the bimetallic structure. These uncertainties need to be taken into account in the dynamic analysis of bimetallic structures. At present, extensive research work has been carried out by scholars for the uncertainty analysis of bimetallic structures. We systematically review the current research status of the uncertainty dynamics of bimetallic structures by scholars at home and abroad in terms of the uncertainty in dynamics, beam dynamics, bolted joint dynamics, etc., and give the problems that need to be further investigated.

Ring artifacts are one of the most common artifacts in all types of computed tomography (CT) images and are usually caused by inconsistent response of detector pixels to X-rays. Effective removal of ring artifacts can greatly improve the quality of CT images and improve the accuracy of later diagnosis and analysis, which is a necessary step in CT image reconstruction. Therefore, the ring artifact removal method (also known as "ring artifact correction") was systematically reviewed. Firstly, the formation mechanism and performance of ring artifacts were introduced. Secondly, the ring artifact correction methods of hardware correction, software correction and deep learning correction are introduced in turn, and the principle, development process, advantages and disadvantages of each type of method are analyzed. Finally, the advantages and disadvantages of the existing ring artifact removal methods are summarized, and the solutions are prospected.

The AlSiC spherical optical element is one of the basic optical elements preferred in modern optical systems. Spherical optical systems not only occupy a leading position in traditional civilian products such as digital cameras and medical devices, but also play an irreplaceable important role in high-tech frontier fields such as lithographic objectives and high-power laser drivers. A theoretical model is established and the mathematical relationship between the standard mirror square focus, the reference plane and the measured sphere is analyzed by using the two-sided sphere method. The experiment verifies the feasibility of using 4mm RMS reference plane to detect 1mmAlSiC RMS surface. The absolute root mean square of the measured surface is about 1mm, and the variation range is ±0.15nm. The absolute root-mean-square measurement of the reference plane is about 4.2mm, and the variation range is ±0.2mm.

Solid-state phase transition is a significant physicochemical phenomenon with applications in materials science, biology, solid-state physics, geo-physics, chemistry, etc. Computer simulations, primarily using molecular dynamics (MD), are able to simulate the microscopic rearrangement processes of the structural units, atoms or molecules, revealing the mechanisms of structural transformation. However, solid-state phase transitions are rare events that are often not observed in typical MD simulations. This time-scale problem is resolved by enhanced sampling simulations, which augment the system's Hamiltonian with history-dependent bias potentials. Finding a suitable set of collective variables is crucial to the effectiveness, dependability, and quality of enhanced sampling. This process frequently involves intuition and multiple iterative optimization processes. T In this paper, we review the collective variables recently applied in solid-state phase transitions, talk about the difficulties that are now being faced, and propose development trends.

Light quality and controllability are crucial factors in plant illumination, posing challenges such as formulating precise light environment and achieving accurate micro-zone lighting. To address these issues, we proposed a resonant cavity light-emitting diode (RCLED) device that incorporates a resonant cavity reflector (RCR) and a metasurface, offering advantages such as high purity and highly directional emission. The RCR, composed of various pairs of distributed Bragg reflectors, was investigated to narrow the full-width at half-maximum (FWHM) of the emitting spectrum, thereby improving the purity. A traditional beam-splitting metasurface was designed to achieve directional emission of the linearly polarized light beam. However, traditional devices with fixed directional emission limit their adaptability. We leverage the Moiré effect to design a two-cascaded metasurfaces system. This device enables tunable deflection angle of the output beam, providing greater flexibility and control. Compared to tradition RCLEDs, our angle-tunable RCR-RCLED with two cascaded metasurfaces boasts a one-third FWHM. Compared to RCR-RCLED integrated with a tradition metasurface, our device has a tunable deflection angle.

In this work, a deep learning network is described that uses a residual network as the backbone and incorporates SE-Blocks to accurately predict illumination. Multispectral images are segmented into small blocks as input to estimate global illumination from local estimates. The network is composed of multiple basic residual blocks and bottleneck residual blocks, integrating feature learning and regression into the optimization process, thereby producing a more effective illumination estimation model. The entire network is trained using the ICVL dataset and tested on the Foster 2022 dataset. Preliminary experiments on images under different lighting conditions have validated the stability of the proposed neural network method for illumination estimation, enhancing the performance of illumination estimation.

This paper presents a comprehensive analysis of the technical principles of air-supported membrane silos and the limitations of distributed photovoltaic component applications. By exploring the feasibility of combining flexible photovoltaic components with flexible materials and the curved design of air-supported membrane silos, it further elaborates on the application direction of integrating large-scale material storage air-supported membrane silos with new energy. This study aims to provide insights for achieving low-cost, environmentally friendly effects, and offering clean energy for various types of large-scale storage silos.

The quasi-bound states in the continuum (BIC) in optical metasurfaces have recently emerged as a promising approach for enriching light-matter interactions at the nanoscale due to their ultrahigh quality factors, showcasing the potential of advancing high-harmonic generation, low-threshold nanolasers, and slow light devices. However, the interplay of the quasi-BICs modes empowered slow light in the near-infrared regions has not been fully explored. Herein, we show that the interplay of the dual symmetry-protected quasi-BICs modes can be exploited for the fulfillment of tunable ultraslow light in all-dielectric metasurfaces that consist of triple parallel silicon rectangular nanorods unit cells. In particular, by adjusting the related structural parameters of the nanorod, the dual symmetry-protected quasi-BICs dominated by the magnetic dipoles can not only be achieved with high-quality factors but the interplay of them can be adopted to realize analogue of electromagnetically induced transparency, leading to the presence of ultraslow light effect (~10^-4c) associated with modulation depth being 19.5 dB. Our results can open a new avenue to explore quasi-BIC-based metadevices and hold great promise for sensors and filters.

Owing to the unique electromagnetic properties, metasurface is able to achieve arbitrary polarization status by planning the shape of the meta-atoms in one unit. Compared to conventional waveplates, due to the compact size of the metasurface based devices, polarization converters with high conversion efficiency have great potential in integrated photonics. In this paper, we present a transmissive polarization converter working in the visible wavelength region which is composed of GaN rectangular rod metasurface array placed on a glass substrate. The metasurface structure exhibits a polarization conversion ratio exceeding 0.8 within the wavelength range of 477-538 nm, and achieves nearly 100% conversion efficiency for linearly polarized light at 503 nm. The transmittance is larger than 0.8 in the identical wavelength range and the highest transmittance of 0.98 is achieved at 503 nm.

Fano resonances (FRs) caused by the interference from the Mie resonances of the all-dielectric metasurfaces can facilitate the realization of stronger field enhancement, tunable wavelength selectivity, and highly sensitive optical sensors. However, single-resonance sensing poses a clear limitation in metasurface-based sensing in complex environments and may be inaccurate and unreliable, making the FRs-based dual-resonance sensing desired and remaining to be explored. Here, we propose polarization-insensitive all-dielectric metasurfaces for high-sensitive dual-resonance sensing in the near-infrared regions, which consist of C₄-symmetric quadrant unit cells. The two Mie resonant modes, dominated by the magnetic dipole and toroidal dipole, have been deployed to characterize polarization-insensitive magnetic FR, capable of supporting refractive index sensitivities of 815 nm/RIU and 456 nm/RIU at wavelengths of 1523 nm and 1585 nm, respectively. Our results may find potential applications in multi-channel sensing and optical modulators.

With the development of fabrication technologies of micro and nano structures, terahertz metasurfaces have led to the emergence of terahertz refractive index sensors with unique performances in the field of biomedicine. Particularly, terahertz refractive index sensors exhibit high sensitivity, high quality factor and low loss which play an important role in the research field of biosensors. In this paper, we propose an asymmetric butterfly-shaped split-ring metasurface array made of gold which are place on the SiO₂ substrate. According to the simulation results, two resonances with high Q-factor are generated in the transmission spectrum. Both resonances show high sensitivities when employed for refractive index sensing. According to the current and electric filed distributions, the two resonant dips in the asymmetric butter fly shaped array is due to the excitation of toroidal dipole and magnetic dipole respectively. A Q-factor of 7.35, S of 250 GHz/RIU and FOM of 2.5 RIU^-1 are obtained at 0.735 THz, and a Q factor of 16.7, S of 400 GHz/RIU and FOM of 6.67 RIU^-1 are obtained at 1.18 THz. The structure parameters are optimized to further enhance the performance of the sensor.

To address the challenge of detecting the extremely weak acoustic signals caused by valve internal leakage, this study investigates a valve internal leakage detection method based on fiber optic acoustic sensors, utilizing characteristic frequencies for valve status determination. Based on shell theory, it is concluded that characteristic frequencies are related to pipeline material and radius. Simulation analysis of the characteristic frequencies of valve internal leakage acoustic signals is conducted, determining the frequency range of leakage acoustic signals. Subsequently, the size of the fiber optic acoustic sensor is optimized according to this frequency band and applied in experiments comparing characteristic frequencies of leakage acoustic signals for different pipeline materials. Results indicate that the higher the Young's modulus of the pipeline material, the higher the characteristic frequency of the valve internal leakage acoustic signal.

To solve the problem of continuous power supply of wireless monitoring system for forest fire, a small electromagnetic-triboelectric complex energy harvester is designed, which can convert wind energy into electric energy and realize real-time monitoring of wind speed. The energy conversion principle and law of triboelectric unit and electromagnetic unit are analyzed by simulation calculation. Test results demonstrate that the electric energy output increases proportionally with wind speed, reaching peak voltages of 13V and 100.9V for the electromagnetic unit and triboelectric unit respectively at a wind speed of 11 m/s. The frequency of open-circuit voltage from the triboelectric unit exhibits a linear relationship with wind speed, allowing for accurate sensing capabilities. By integrating a temperature and humidity acquisition module, positioning module, a flame sensor, an energy management circuit, and an energy storage module, a wireless monitoring system for forest fires is established to capture wind energy while transmitting temperature, humidity, and other information to mobile clients via Bluetooth technology. The system has important application value in the field of forest fire warning and prevention.

In the process of recharging a rechargeable battery, a protective film, the solid electrolyte interface is created atop the anode. This barrier is crucial for both charge and discharge operations within the battery due to its unique characteristics. Recent studies have focused on improving anode performance by controlling SEI formation. Despite these advancements, there is still much to learn about how SEI conductivity enhancements occur and what specific changes in SEI composition and structure take place over time. This document provides a concise overview of recent findings concerning ion transport in the SEI layer. It examines various approaches for cultivating a stable SEI, focusing on its compositional structure, ion transmission properties, and optimization tactics. Leveraging contemporary research insights, this paper offers general guidance and prospective views for experts in this domain to consider as they further their investigations.

Taking a certain optical mold as the research object, addressing the issues of prolonged cooling time and warping deformation of the product due to uneven cooling that affects optical performance, a conformal cooling channel based on 3D printing technology was designed and simulated with Fluent fluid analysis software. By comparing the simulation results of traditional drilled channels, single-channel conformal channels, and multi-micro parallel conformal channels, it was found that the multi-micro parallel conformal channels can significantly improve the cooling efficiency of the injection molding process and reduce the temperature difference on the molding surface of the mold, where the molding cycle was shortened by 23.3%, and the temperature difference on the molding surface of the mold during the injection molding process was reduced to within 1.2℃.

The demodulation and reproduction of external vibration signals in submarine cables have broad prospects for practical engineering applications [1]. Based on the phenomenon of Rayleigh scattering, Phase-Sensitive Optical Time Domain Reflectometry (Φ-OTDR) serves as a type of distributed fiber sensing technology, widely applied in various fields due to its advantages of long monitoring distance, high sensitivity, and resistance to electromagnetic interference. This paper demonstrates the design of a simple and low-cost demodulation system for audio vibration signals directly monitored by Φ-OTDR. In the experimental setup, the fiber under test is wound around the outer surface of a polypropylene tube. Music and voice signals are played through speakers to the fiber under test, proving that this system can reproduce multifrequency external vibration signals over a transmission distance of 50 km with a spatial resolution of 5 meters. This system is suitable for long-distance monitoring of external vibration signals.

After aggregation-induced emission (AIE) was proposed by professor Tang in 2001, the research about AIE molecules and their application have been received widespread attention because of their high photoluminescence quantum efficiencies in the aggregation or solid film states. Developing different AIE polymers had always been a research hotspot in this field. Herein, an AIE-active main-chain polymer TPB-PA based on tetraphenylbutadiene (TPB) was prepared by polycondensation of TPB derivatives with two carboxylic acid groups and diamine. The AIE behavior of TPB-PA was measured in the THF/H₂O mixtures. The fluorescence intensity starts to increase gradually when the water fraction (f_w) is 20%, enhances significantly when f_w is higher than 60%, and reaches the maximum and is 6.8 times of the original intensity at f_w = 90%, which indicates their significant AIE characteristics. Furthermore, the fluorescence spectra of TPB-PA and its precursor TPB-COOCH₃ changed obviously when adding different concentration of lubricants to their THF solution, and the different kinds of lubricants have different influence on the photoluminescence properties, which can be used to recognize different kind of lubricants.

The icing on overhead transmission lines plagues the electricity industry. Superhydrophobic anodized Aluminum-conductor steel-reinforced was successfully prepared by designing the cylindrical cathode and changing the additive concentration of ethylene glycol. Results show that increased addition of ethylene glycol can mitigate the vigorous dissolution of nanopores structure. This is beneficial to the formation of uniform nanopores structure and thicker anodic oxide film. The additive concentration of 10% forms the most intact nanopore structure of good superhydrophobicity (154.1°) and low ice adhesion (6.5 kPa). The prepared superhydrophobic Al conductors show good application in the anti-icing overhead lines.

China’s cold chain logistics fresh loss rate far exceeds that of developed countries, and SiO₂ aerogel coating has a broad development prospect in the field of cold chain transportation packaging. In this paper, we analyze the preparation method, thermal insulation as well as hydrophobic properties of SiO₂ aerogel. The influence of aerogel slurry and content on the thermal insulation properties are discussed, and the top-down and bottom-up methods for the construction of superhydrophobic surfaces and the modification of SiO₂ aerogel hydrophobization are summarized. The progress of aerogel coating research is discussed, and the future research focus and application direction of aerogel coatings are clarified.

Composite structures used in aircraft need to deal with a wide variety of climatic conditions, such as high temperature, cold temperature, and hydrothermal environment, which probably affects their bearing capability and life expectancy. Additionally, tapered composite laminates are commonly adopted to accommodate the need for varying thicknesses in aircraft structures. Consequently, environmental influence on the tapered composite structures has become a major concern in the utilization of composites. In this work, an experimental program is executed on the tapered composite structures in room temperature atmosphere (RTA), cold temperature dry (CTD), and elevated temperature wet (ETW) conditions separately. The results indicate that the large stress concentration induced by the presence of discontinuous plies in the tapered section motivates the occurrence of delamination at a relatively low load. Environmental exposure does not have a distinct effect on the delamination initiation load. In the hydrothermal environment, the degradation of tensile strength is negligible, and the delamination process as well as the failure pattern of ETW specimens are similar to RTA ones. However, cryogenic conditions result in a severely deteriorating effect on the tensile strength. The failure pattern of CTD specimens exhibits a brittle fracture characteristic and no obvious yield process is observed.

A series of poly (acryloyl pyrrolidine) (PAPy_x, x = 25, 50, 100, 200, and 300, respectively) and PAPy-r-poly(N, N-dimethyl acrylamide)s (PAPy_x-r-PDMAm_y, x + y = 100) were synthesized by group transfer polymerization (GTP). The structure of PAPy_x (x = 25, 50, 100, 200, and 300) and PAPy_x-r-PDMAm_y (x + y = 100) were measured by SEC and ¹H NMR. The thermo-responsive properties of PAPy_x and PAPy_x-r-PDMAm_y were measured based on the cloud point temperature (T_c). For PAPy_x (x = 25, 50, 100, 200, and 300), with increased M_w,_MALS, the T_c was 50.1°C about the x of 200. For PAPy_x-r-PDMAm_y (x + y = 100), only PAPy₇₅-r-PDMAm₂₅ showed a transmittance lower than 50% with increased temperature and T_c was 52.8 °C. PAPy₅₀-r-PDMAm₅₀ and PAPy₂₅-r-PDMAm₇₅ exhibited a slow decrease in transmittance without T_c.

In order to effectively suppress the radiated noise of transformers, borrowing the acoustic package design concept from electric vehicle parts, we used the test methods to get aluminum silicate wool porous material Johnson-Allard acoustic parameters (JCA parameters: porosity, flow resistance, tortuosity, visco-thermal characters), and built the transformers with acoustic package model based on the FEA (finite element analysis) method to get the noise reduction performance. For verify the acoustic package simulation model and concept performance on transformer, a 500kV transformer noise reduction test is done. The study results show that the measured results are highly consistent with the simulation results, laying a solid application foundation for the acoustic package design of noise reduction schemes for other power equipment in the future.

Mechanofluorochromic (MFC) materials, as a kind of fluorescence stimulus response materials, can show obvious changes under external stimuli, so it has become a research hotspot in the field of advanced optical materials. MFC compounds can further benefit their properties from stimulus-responsive materials with aggregation-induced emission (AIE) characteristics. Therefore, by combining triphenylethylene with benzimidazole derivatives, we designed and synthesized a simple organic small molecule DTITA with AIE and reversible mechanofluorochromism characteristics, and the material of solid fluorescence can be regulated through the utilization of mechanical grinding and DCM fumigation cycles. This offers a new way for the invention of new intelligent materials.

Nano-particle epoxy resin composites are More applications in the field of electrical insulation. To study nanoparticle dispersion, mass fraction the role of dielectric properties of SiO₂/ epoxy composites. In this paper, three methods, the Ultrasonic Dispersion Method, Sol-gel Method, and High-speed Mixer Method, were prepared by nano-SiO₂ mass fraction of nano-SiO₂/epoxy resin composites with 1-4 wt%. The dispersion of nanoparticles in the composite was characterized quantitatively to test the corona-resistant characteristics and breakdown characteristics. Dielectric experiments of samples found that with nano-SiO₂/epoxy resin composites, compared to the pure epoxy resin material of the dielectric constant, dielectric loss increased, breakdown field strength increased, and corona-resistant performance was enhanced. With the increase of the content of nano-SiO₂ with three kinds of preparation methods of nano-composite, the dielectric constant was increased and reached the maximum when the mass fraction of SiO₂ was 3 wt%; it then decreased. The dielectric loss increased. When the mass fraction of SiO₂ is 3 wt%, the breakdown field strength is the maximum, and then decreased. The results show that the dispersion of nanoparticles is better. The smaller the dielectric constant of the composite becomes, the better the breakdown performance is, and the stronger the corona resistance will be.

Dissolved Gas Analysis (DGA) is a specialized method that assesses the condition of transformers by analyzing dissolved gases in transformer oil. It provides valuable insights into potential faults and their severity without requiring power outages, remaining unaffected by external electrical and magnetic fields. Gas Chromatography (GC) and Photoacoustic Spectroscopy (PAS) are commonly used techniques in DGA, yet comparative experiments evaluating their performance in online measurement applications are lacking. To address this gap, experiments were conducted using 30 sets of oil samples obtained from operational local substations. These samples, sourced from transformers with over 3 years of service and stored under sealed conditions, were meticulously analyzed. A comparative experiment platform was established using a self-made PAS module and a commercial GC apparatus. The comparative analysis revealed a remarkable consistency between PAS and GC in measuring dissolved gas concentrations in diverse oil samples. Both techniques demonstrated their effectiveness in determining the composition and concentration of dissolved gases. Noteworthy discrepancies were observed in PAS measurements, attributed to the introduction of air during the sampling process, leading to elevated concentrations of CO2 and CH4 and subsequent signal amplification for other gases. This study underscores the reliability of both PAS and GC as invaluable tools in DGA, providing critical insights into the dissolved gas content in transformer oil samples and aiding in the accurate assessment of transformer status.

The carbon-fluorine bond exhibits a low level of polarization, which gives the organic fluoropolymer coating material a distinctive property of reduced surface energy. As a result, it demonstrates exceptional resistance to both polar and nonpolar molecules and can resist the permeation and swelling of water, oil, and other liquids. The present paper provided a concise overview of three types of fluoropolymer coating materials based on acrylates, polysiloxanes, and nanoparticles. The unique chemical compositions or structures of fluoropolymer coating resulted in good hydrophobicity, oleophobicity, solvent resistance, antifouling and decay resistance, UV resistance, and self-cleaning capabilities. The present study introduced four preparation methods for fluoropolymer coating materials, including free radical polymerization, anionic polymerization, hydrosilylation, and click chemistry. At the same time, the film-forming methods of fluoropolymer coatings, such as temperature-controlled cross-linking curing methods of epoxy-amine reaction and siloxane hydrolysis condensation, as well as photoinduced cross-linking curing methods, are covered. Grafting fluorine-containing segments into polymers to reduce the surface energy and introducing nanoparticles to fabricate microstructure are two key aspects of the study of protective coatings. The prospects of protective coatings made from fluoropolymers were proposed.

The effects of commonly added microalloying elements on the organizational properties of Ti₂AlNb alloys are described, the direction of better microalloying systems to obtain the best overall performance is identified, and the effects of different alloying element types as well as their contents on the microstructure and properties of Ti₂AlNb alloys are comparatively analysed to put forward the problems existing in the current research, and to think about the direction of the development of the future Ti₂AlNb alloy material process.

Lowering the Pt loading would decrease proton exchange membrane fuel cell (PEMFC) cost, but inevitably increase local oxygen transport resistance and cause performance loss at high current densities. To enhance the local oxygen transport within the catalyst layer, the heat treatment method of the electrode is proposed to regulate ionomer microstructure. After heat-treating the electrode over the ionomer glass-transition temperature, the local oxygen transport resistance decreases and the limiting current density enlarges, which in turn improves the cell performance at high current densities, confirming the enhancement of oxygen transport. Based on the AFM and contact angle test results of thin-film ionomers, it can be further confirmed that the phase-separation within thin-film ionomers is enhanced after heat treatment that builds more oxygen transport pathways inside the ionomer. This work offers a simple and effective method to enhance the local oxygen transport process and is beneficial for future high performance PEMFC development.

This study aimed to explore how Mo content impacts the microstructure and properties of (Ti, W) C-CoCrNi-based cermets. Samples with varying Mo content were prepared by using powder metallurgy. Various methods, including X-ray diffraction analysis, scanning electron microscopy observation, hardness testing, and magnetic property measurements, were employed to systematically study the role of Mo in the cermets. The study showed that as Mo content increased, there was a gradual reduction in the grain size of the material and the grain distribution became uneven. The addition of 1~5 wt.% Mo did not alter the magnetism of the cermets, and all cermets presented paramagnetism at room temperature. As the Mo content increases, the bending strength of cermets gradually decreases. The hardness of the cermets increased from 86 HRA to 87.9 HRA as Mo content was raised from 0 to 1 wt.%. However, as the Mo content continued to increase, the hardness values showed little change.

Selective laser melting additive manufacturing has been employed previously to fabricate lightweight metal mirrors that can be used in aerospace, astronomy, and other fields. However, additively manufactured mirrors have poor surface roughness, which limits their use in practical applications. In this study, additively manufactured mirrors were fabricated with high surface densities for their application in different wavelength bands. Two methods were proposed to fabricate opto-mechanical components, of which one approach involved the fabrication of mirrors that could be used with longer wavelengths. After hot isostatic pressing, the porosity (which is an intrinsic characteristic of 3D printing) and roughness of the mirror substrate were 0.005% and < 8 nm, respectively. To further improve their surface quality, the mirrors were coated with pure Al, which facilitated the matching of the thermal expansion coefficients of the layer and the AlSi10Mg mirror substrate; these mirrors could be used with shorter wavelengths. The roughness of the mirror became < 2 nm when it was coated with pure Al and subjected to optical processing. This approach can be applied to fields that require low-temperature detection techniques, such as aerial measurement and remote sensing, low-temperature light tubes, and near-space detection systems.

Lithium ion battery cathode material LiFe_1-xMn_xPO₄/C was prepared by high temperature solid state method, and the effects of Mn modificatin on the structure, morphology and electrochemical properties of the material were researched. The results show that the olivine structure lithium manganese iron phosphate material was obtained by high temperature solid state method, and no impurity phase existed. A small amount of Mn doping does not have much influence on the structural morphology of the material, but significantly improves the electrochemical performance. When the Mn content was 0.02 (molar content), the specific discharge capacity of the material reached 154mAh/g at 0.2C rate, which is significantly higher than that of the Mn content was 0.00 (molar content). Moreover, Mn doping can effectively improve the capacity performance at high rate. And the electrochemical reaction resistance is reduced, explaining that the addition of Mn improved the electrochemical performance of the material.

In recent years, with the rapid development of new energy power system and energy Internet, how to select excellent magnetic core materials of high-frequency transformers and solve the loss problem of transformers under high-frequency conditions is one of the current research hotspots. As an ideal core material for high-frequency transformers, nanocrystalline iron cores have excellent magnetic properties and have attracted extensive interest in the field of electrical engineering. In order to understand the mechanism of magnetic properties of nanocrystalline materials under high frequency sinusoidal conditions, a three-dimensional mesoscopic model of nanocrystalline magnetic core was constructed by using micromagnetic simulation software. The mechanism of high-frequency magnetization reversal is revealed by studying the process of magnetic domain from forward saturation to reverse saturation, and the influence of frequency on magnetization rate and hysteresis is studied. The results show that the magnetization reversal process of nanocrystalline magnetic core is faster at higher magnetic field frequency and has more obvious hysteresis effect.

High entropy alloys with unique mechanical properties and irradiation resistance exhibit promising potentials as structural materials for advanced nuclear facilities. However, the formation behavior of irradiation defects in HEAs is still lacking of understanding. In this study, molecular dynamics simulations were employed to investigate the cascade collision of energetic ion in TiVTa and V, in order to compare the difference of their irradiation response. The results indicate that there is no significant difference in the initial stage of irradiation between these two materials, but as the irradiation damage accumulated, the residual defects in V is much more than in TiVTa, indicating that the recombination and annihilation rate of point defect in TiVTa is faster than in V. Mean square displacement calculations were also carried out to prove that self-interstitial atoms and vacancies have similar migration rate in TiVTa, therefore the self-interstitial atoms and vacancies produced in cascade collisions are more susceptible to combine and annihilate. These results will be helpful to unveil the mechanism of the irradiation response of HEAs.

In this work, MoS₂/BiOBr heterojunctions was prepared to applicate in degradation of Rhodamine B. It was studied comparatively with the pristine MoS₂ and BiOBr. Use the detecting instrument tester such as X-ray diffraction (XRD) to confirm the formation of a composite heterostructure between MoS₂ and BiOBr. MoS₂/BiOBr showed excellent photocatalytic degradation efficiency toward Rhodamine B, which reaches 96.01% in 1 hour. It is 3.3 times higher than MoS₂, and 1.6 times than BiOBr, respectively.

In recent times, there has been significant interest in ultraviolet-excited white light-emitting devices (WLEDs) for the advancement of solid-state lighting technologies. However, it is still a huge challenge to get efficient blue and yellow light emission under the same excitation wavelength. Here, Sb-doped Cs₂NaInCl₆ (Cs₂NaInCl₆:Sb³⁺) and Sb-doped Cs₂InCl₅·H₂O (Cs₂InCl₅·H₂O:Sb³⁺) with stable and efficient blue and yellow light emission, and highly overlapped excitation wavelength ranges were reported. Then, by applying shell layers of Cs₂InCl₅·H₂O: Sb³⁺ on the core of Cs₂NaInCl₆:Sb³⁺ , a variation from blue to cool-white, pure-white, warm-white and yellow was achieved. Amazingly, the pure-white light emitting core-shell MCs achieved a high photoluminescence quantum yield (PLQY) up to 70% under the radiation of the same wavelength. More importantly, the as-prepared core-shell MCs exhibited excellent UV, heat, and storage stability, which made it possible for the application as phosphor in WLEDs. Finally, the core-shell MCs prepared in this study were applied onto a 310 nm UV LED chip to produce the WLEDs. These WLEDs exhibited an exceptionally high color rendering index of 94.5, along with a pure-white Commission Internationale de L’Eclairage color coordinate of (0.31, 0.32), and demonstrated remarkable long-term operational stability. The outstanding optical properties and stability observed in the WLEDs suggest promising applications for the Cs₂NaInCl₆:Sb³⁺ @ Cs₂InCl₅·H₂O:Sb³⁺ core-shell MCs in next-generation solid-state lighting.

Due to the simultaneous presence of two polar functional groups and flexible spatial structure, Aminoethanol (AE) is a model system for investigating the relationship between intramolecular hydrogen bonding and conformational equlibrium. In addition, Aminoethanol and their derivatives exhibit remarkable efficacy in the reversible capture of carbon dioxide. The intramoleculr hydrogen bond of 2-AE is determined by a subtle balance between electrostatic interactions, Van der Waals interactions, and steric effects. Changing the polarity of functional groups can regulate the strength of intramolecular hydrogen bonds. In this work, using spontaneous Raman spectroscopy combined with theoretical calculations, we investigated the effect of N-terminated substitution group on intramolecular hydrogen bond. When the H atom of NH2 functional group is replaced by electron-donating groups such as methyl and ethyl, it was observed experimentally that the red-shift of OH stretching vibration frequency caused by O-H... N intramolecular hydrogen bonding increases significantly and then the corresponding peak intensity increases. This indicates that with the introduction of substitutions on the N atom, the O-H... N intramolecular hydrogen bond in 2-AE is enhanced and the corresponding conformational population increases. The results of AIM and NCI analysis are consistent with experimental observations. These results provide insights for regulating the strength of intramolecular hydrogen bonds and also contribute to the strategy of CO2 capture.

To solve the contradiction between miniaturization of photoelectric encoders and high-precision measurement, a matrix coding and decoding method based on 16 quadrants is proposed in this paper. 21-bit matrix coding can be realized by engraving two circles of matrix code tracks, compared with traditional optoelectronic encoders, this encoder achieves higher accuracy with fewer code circles. In this paper, the design of a new-type matrix code disk, the design of coding and decoding methods and simulation analysis are mainly carried out. Theoretical calculation and simulation analysis show that the encoder designed is feasible, and this paper proposes a new method for the miniaturization and high-precision measurement of encoder.

This article reports the preparation and research of poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl C61-butyric acid methyl ester (PC61BM)/Zinc oxide (ZnO) UV-visible dual-band photodetectors (PDs). At room temperature, ZnO, PC61BM and P3HT films were deposited on the FTO substrate using radio frequency magnetron sputtering technology and sol-gel technology respectively. A selective planar heterojunction organic photodetector was prepared using p-type polymer P3HT and n-type fullerene acceptor PC61BM as double active layers. Controlling phase separation in a binary complex system of donor and acceptor to improve hole extraction efficiency. This heterojunction has good UV-visible detection capabilities. Under a 2 V bias condition, the PD has a UV-visible dual-band response, with a peak at 380 nm of 0.072 A/W, and high wavelength selectivity. This demonstrates a facile method to prepare an organic-inorganic composite photodetector with high performance.

Flexible zinc oxide (ZnO) photodetectors have attracted widespread attention due to their advantages such as light weight, good flexibility, good photoelectric performance, and flexible preparation processes. This study successfully prepared high-quality ZnO thin films on polyethylene terephthalate (PET) flexible substrates using magnetron sputtering method, and completed the preparation of photodetectors by evaporating silver electrodes on the surface of the thin films. Afterwards, we tested and characterized the photoelectric performance of the prepared detector, and the results showed that the detector has good photoresponse characteristics and stable photocurrent output. The preparation of this detector on a flexible substrate provides strong support for its applications in wearable electronics, flexible displays, and other fields. This study provides valuable insights for the future development and utilization of flexible ZnO photodetectors.

Because some Schiff bases have some special biological activities, the use of Schiff bases as ligands to form complexes with metal ions can show good biological activities. Amino acids, Schiff bases and their corresponding ligands have been reported to have unique antibacterial, bactericidal, anti-tumor, antiviral and detoxification effects. Therefore, complexes formed by rare earth metals and Schiff base ligands have attracted much attention due to their diverse structures. In this paper, the luminescence mechanism of rare earth polymers and the synthesis and fluorescence properties of rare earth Schiff base ligand complexes are reviewed. The research progress of Schiff base rare earth near-infrared luminescent complexes in the fields of medicine, antibacterial materials and bioimaging was reviewed. The future application and research of Schiff base were also prospected. Because some Schiff bases have some special biological activities, Schiff bases are used as ligands to form complexes with metal ions, which can show good biological activities. It is reported that amino acids, base acids, Schiff bases and their corresponding ligands have unique effects of antibacterial, bactericidal, anti-tumor, anti-viral and detoxification. Therefore, complexes formed by rare earth metals and Schiff base ligands have attracted people's attention due to their diverse structures and wide applications. In this paper, the luminescence mechanism of rare earth polymers is summarized, and the synthesis and fluorescence properties of mononuclear, binuclear and multinuclear rare earth complexes of Schiff base ligands are reviewed. The research progress of Schiff base rare earth nearinfrared luminescent complexes in medicine, antibacterial materials, bioimaging and other fields was summarized, and their future application and research were prospected.

Using 4-mercaptomethyl-3, 6-dithio-1,8-octyl dithiol and divinylbenzene as raw materials and 2-hydroxy-2-methylphenylacetone as photoinitiator, the results showed that the polymers had excellent optical properties. Among them, when the functional group molar ratio of thiol to double bond was 3:5, the polymer film transmittance was 94%, and the refractive index reached 1.613. In terms of adhesive application, the cured polymer achieved an adhesive strength of 0.9 MPa on polar glass, and thus it can be considered for use as an optical adhesive. In addition, the monomer blends exhibited excellent normal temperature and high temperature storage stability within 30 days.

Zinc oxide (ZnO) with a wurtzite structure exhibits excellent optoelectronic and semiconductor properties, thus showing promising applications in the field of ultraviolet (UV) detection. However, the existing ZnO-based UV photodetectors on rigid substrates are limited in practical applications due to the constraints of rigid substrates, making it difficult to meet the complex and demanding environmental requirements. In this work, ZnO thin films were deposited on flexible polyethylene terephthalate (PET) substrate by radio frequency (RF) magnetron sputtering technique. Metal-semiconductor-metal (MSM) structured ZnO UV photodetectors were fabricated. The influence of oxygen-argon ratio on the deposition of ZnO thin films and the performance of flexible UV photodetectors was investigated. It was found that ZnO thin films exhibited higher crystalline quality when the oxygen-argon ratio was 10:40. This research provides a material basis for the development of flexible UV photodetectors.

In this paper, a new uniplanar-compact electromagnetic bandgap structure is presented, which can significantly restrain synchronous switching noise (SSN) in high-speed circuits across a broad frequency spectrum. This innovative EBG design builds upon the foundation of the L-bridge EBG with slits, incorporating the C-type EBG structure for enhanced performance. Simulation results demonstrate that our proposed EBG structure achieves ultrawideband SSN suppression, ranging from 0.45GHz to 25GHz at -30dB. This represents a significant improvement compared to traditional L-bridge EBG with slits and C-bridge structures. Furthermore, we delve into the underlying reasons for the new structure's ultrawideband SSN suppression capabilities through analysis based on its equivalent circuit model. Additionally, electromagnetic (EM) simulation and power delivery network (PDN) analysis simulation are conducted for the proposed structure, and the results are comprehensively plotted for further examination

The near-infrared spectroscopy technology has been widely used in the identification of plastic materials. In this paper, the analysis of spectra preprocessing methods and wavelength selection methods is carried out for the accurate identification of seven plastic materials, including PET, PE, HDPE, ABS, PP, PS, and PVC. Three spectra preprocessing methods, including Multivariate Scatter Correction, Standard Normal Variate, Savitzky-Golay filtering coupled with Standard Normal Variate and three feature wavelength selection methods, including Successive Projections Algorithm, Genetic Algorithm and Competitive Adaptive Reweighted Sampling were compared and analyzed. The experimental results showed that the identification model built based on Support Vector Machine using the Standard Normal Variate after Savitzky-Golay filtering spectra preprocessing method and the Competitive Adapative Reweighted Sampling wavelength selection method had the highest accuracy, with an accuracy of 99.81% in recognizing the seven plastic materials.

Nickel oxide (NiO_x) is a very promising material for hole transport layer (HTL) in perovskite light-emitting diodes (PeLEDs). However, its device performance is limited by the agglomeration of nickel oxide nanoparticles (NPs) and the poor quality of perovskite films deposited on nickel oxide. In this paper, 1-hydroxyethyl-3-methylimidazolium tetrafluoroborate ionic liquid (IL) was introduced into NiO_x dispersions as a surfactant to enhance the dispersion of NPs and improve the topographic quality of NiO_x films. Meanwhile, IL can interact with uncoordinated Ni and Pb at the NiO_x/perovskite interface, which contributes to the formation of high-quality perovskite films for efficient carrier radiation recombination. As a result, we achieve NiO_x-based blue PeLEDs with a maximum efficiency of 4.2% and a maximum luminance (L_max) of 703 cd m^-2 . This work contributes to an efficient approach to optimize the dispersion of NiO_x NPs as well as the interface between NiO_x and perovskite for highly efficient blue PeLEDs.

As one of the key parts of display devices, the selection of luminescent materials is crucial to promote the development of display technology. Fully inorganic perovskite quantum dots (QDs) are ideal light-emitting materials for next-generation display devices. However, quantum dots based on CsPbX₃ (X=chlorine, bromine, iodine) have poor stability and are vulnerable to external environmental erosion (such as oxygen, water) decomposition, damaging optical properties. In this work, we used mesoporous silica to protect perovskite by growing CsPbBr_xI_3-x in situ in mesoporous silica. Compared with the red perovskite quantum dots synthesized by traditional methods, the stability was improved, More than 96% of the PL intensity was maintained after 30 days of storage under environmental conditions. There was no significant change after continuous heating at 100°C for 60 min, and more than 80% of the PL intensity was maintained after 5W blue light irradiation for 48 h at 365 nm excitation wavelength.

The development demand for lightweight and low dielectric properties of resin based wave-transparent composite materials. This article replaces traditional glass fibers with PBO fibers with lower dielectric constant and lower density as the reinforcement material for wave transmitting composite materials. To improve the mechanical properties of PBO reinforced cyanate ester composite materials, a plasma process was used to modify the surface of PBO fiber fabric. The influence of plasma process on the surface chemical composition, microstructure, and mechanical properties of PBO fiber was analyzed. The interlayer shear strength of PBO/CE composite materials was increased by 45%, and the interlayer shear strength was 29.8 MPa. The modified fiber composite material has a dielectric constant of 3.3 and a loss tangent of 0.005 at 10GHz, exhibiting excellent dielectric properties. The tensile strength at room temperature of the composite material is 591MPa, and the bending strength is 336MPa, indicating good comprehensive mechanical properties. As a new type of transparent composite material, it has broad application prospects in fields such as aircraft, missiles, satellites, sea-based and land-based radar radomes, as well as high-performance printed circuit boards.