2022

• Record 457 of
  
  Title:Bovine Serum Albumin Detection by Graphene Oxide Coated Long-Period Fiber Grating
  
  Author(s):Wang, Ruiduo(1,2); Wu, Hao(1); Qi, Mei(3); Han, Jing(1); Ren, Zhaoyu(1)
  Source: Photonic Sensors  Volume: 12  Issue: 3  DOI: 10.1007/s13320-022-0649-6  Published: September 2022  
  Abstract:A biosensor for bovine serum albumin (BSA) detection by graphene oxide (GO) functionalized micro-taped long-period fiber grating (GMLPG) was demonstrated. The amide bond connected between the GO and BSA enabled the BSA to attach onto the fiber surface, which changed the effective refractive index of the cladding mode and characterized the concentration of the BSA. This real-time monitoring system demonstrated a sensing sensitivity of 1.263 nm/(mg/mL) and a detection limit of 0.043 mg/mL. Moreover, it illustrated superior measurement performance of higher sensitivity in the presence of glucose and urea as the interference, which showed static sensitivities of ∼1.476 nm/(mg/mL) and 1.504 nm/(mg/mL), respectively. The proposed GMLPG demonstrated a great potential for being employed as a sensor for biomedical and biochemical applications. © 2022, The Author(s).
  Accession Number: 20220511544163
• Record 458 of
  
  Title:Snapshot compressive spectral - depth imaging based on light field
  
  Author(s):Ding, Xiaoming(1,2); Yan, QiangQiang(2); Hu, Liang(3); Zhou, Shubo(4); Wei, Ruyi(2,5); Wang, Xiaocheng(1); Li, Yupeng(1)
  Source: Eurasip Journal on Advances in Signal Processing  Volume: 2022  Issue: 1  DOI: 10.1186/s13634-022-00834-x  Published: December 2022  
  Abstract:This paper proposes a snapshot Compressed Light Field Imaging Spectrometer based on compressed sensing and light field concept, which can acquire the two-dimensional spatial distribution, depth estimation and spectral intensity of input scenes simultaneously. The primary structure of the system contains fore optics, coded aperture, dispersion element and light field sensor. The detected data can record the coded mixture spatial-spectral information of the input scene with direction information of light rays. The datacube containing depth estimation can be recovered with the compressed sensing and digital refocus framework. We establish the mathematical model of the system and conduct simulations for verification. The reconstruction strategy is demonstrated for the simulation data. © 2022, The Author(s).
  Accession Number: 20220611597174
• Record 459 of
  
  Title:Extreme learning machine and genetic algorithm in quantitative analysis of sulfur hexafluoride by infrared spectroscopy
  
  Author(s):Liu, Huan(1,2,3); Zhu, Jun(4); Yin, Huan(4); Yan, Qiangqiang(1,2); Liu, Hong(1,2); Guan, Shouxin(1,2,3); Cai, Qisheng(5); Sun, Jiawen(6); Yao, Shun(4); Wei, Ruyi(1,2,3,7)
  Source: Applied Optics  Volume: 61  Issue: 10  DOI: 10.1364/AO.450805  Published: April 1, 2022  
  Abstract:Owing to the general disadvantages of traditional neural networks in gas concentration inversion, such as slow training speed, sensitive learning rate selection, unstable solutions, weak generalization ability, and an ability to easily fall into local minimum points, the extreme learning machine (ELM) was applied to sulfur hexafluoride (SF6) concentration inversion research. To solve the problems of high dimensionality, collinearity, and noise of the spectral data input to the ELM network, a genetic algorithm was used to obtain fewer but critical spectral data. This was used as an input variable to achieve a genetic algorithm joint extreme learning machine (GA-ELM) whose performance was compared with the genetic algorithm joint backpropagation (GA-BP) neural network algorithm to verify its effectiveness. The experiment used 60 groups of SF6 gas samples with different concentrations, made via a self-developed Fourier transform infrared spectroscopy instrument. The SF6 gas samples were placed in an open optical path to obtain infrared interference signals, and then spectral restoration was performed. Fifty groups were randomly selected as training samples, and 10 groups were used as test samples. The BP neural network and ELM algorithms were used to invert the SF6 gas concentration of the mixed absorbance spectrum, and the results of the two algorithms were compared. The sample mean square error decreased from 248.6917 to 63.0359; the coefficient of determination increased from 0.9941 to 0.9984; and the single running time decreased from 0.0773 to 0.0042 s. Comparing the optimized GA-ELM algorithm with traditional algorithms such as ELM and partial least squares, the GA-ELM algorithm had higher prediction accuracy and operating efficiency and better stability and generalization performance in the quantitative analysis of small samples of gas under complex noise backgrounds. © 2022 OSA - The Optical Society. All rights reserved.
  Accession Number: 20221511953938
• Record 460 of
  
  Title:Velocity history measurement of hypersonic tunnel driver based on photon Doppler velocimeter
  
  Author(s):Hao, Ge-Yang(1,4); Yang, Yu-Cheng(1,4); Zhao, Rong-Juan(2); Lü, Xiao-Peng(1); Yang, Ya-Han(3); Wu, Guo-Jun(1,3)
  Source: Wuli Xuebao/Acta Physica Sinica  Volume: 71  Issue: 23  DOI: 10.7498/aps.71.20221234  Published: December 5, 2022  
  Abstract:The research of hypersonic process is limited by the transition model, the turbulence model, and the computational complexity. At present the tunnel test is still a better way to investigate the hypersonic process than the computational fluid dynamic (CFD) method. In this work, the principle and structure of all-fiber photon Doppler velocimeter (PDV) are introduced. The PDV is based on laser Doppler effect and consists of an all-fiber Mach Zehnder interferometer and an optical antenna. The measurement accuracy and distance of PDV are tested, showing that the error can be controlled to be within 0.17 m/s when the velocity of piston is below 40 m/s. At the same time, the measured distance of PDV can reach 26.3 m. The continuous velocity of the free piston is measured by using the PDV in high enthalpy expansion tunnel of China aerodynamics research and development center (CARDC). During the tunnel tests, the PDV is placed next to the tunnel, and the optical antenna is installed behind the observation window of the tunnel and connected to a circulator by optical fiber. When the driving pressure of the tunnel is 1.3 MPa, the maximum numerical simulation velocity of the piston is 88.981 m/s, and the velocity is measured to be 88.810 m/s with a relative deviation of –0.19%; when the driving pressure of the tunnel is 2.7 MPa, the maximum numerical simulation velocity of the piston is 125.100 m/s, the measured velocity is 123.843 m/s, and the relative deviation is –1.00%. The piston reaches a maximum velocity before impacting on the tunnel, and then decelerates rapidly under the joint action of the driving pressure and compression wave. Therefore, the soft landing of the piston proves feasible, which is put forward by Stallkerin the 1960s. Finally, the reasons why PDV missed the impact velocity of piston is discussed. Through the analysis of received intensity, it is believed that the absorption, scattering and expansion of the laser beam caused by the strong driving pressure is the main reason. © 2022 Chinese Physical Society.
  Accession Number: 20225013237309
• Record 461 of
  
  Title:An Investigation of the Fengyun-4A/B GIIRS Performance on Temperature and Humidity Retrievals
  
  Author(s):Wang, Sufeng(1,2); Lu, Feng(3); Feng, Yutao(1)
  Source: Atmosphere  Volume: 13  Issue: 11  DOI: 10.3390/atmos13111830  Published: November 2022  
  Abstract:The Fengyun-4A/B (FY-4A/B) geostationary satellite carries the Geostationary Interferometric Infrared Sounder (GIIRS). The instrument parameters of the GIIRS on FY-4A and FY-4B are not exactly the same, which is crucial for the atmospheric temperature and humidity measurements. The objective of this paper is to discuss the influence of spectral range on the retrieval for the FY-4A/B GIIRS. Firstly, we performed channel selection to choose the appropriate channels for retrieval. Then, the multiple cycling utilization of the physical retrieval method is proposed and conducted for improving the accuracy, and the retrieval results of FY-4A/B GIIRS are compared. Finally, perturbation analysis is performed to discuss the sensitivity of the retrieval to temperature perturbations due to the difference in spectral range between the two GIIRS. The results show the retrieval method can realize the improvement of the average accuracy by more than 0.9 K for temperature and 3.0% for humidity. As the spectral range widens, the retrieval accuracy of FY-4B GIIRS is superior to that of FY-4A GIIRS from 130 hPa to 400 hPa. Furthermore, perturbation analysis also shows the extension of the spectral range is beneficial to the retrieval. This study could offer the usefulness of current GIIRS instruments with observed on-orbit bias, and a reference for the parameter design of the subsequent instruments. © 2022 by the authors.
  Accession Number: 20224613106808
• Record 462 of
  
  Title:A Tracking Imaging Control Method for Dual-FSM 3D GISC LiDAR
  
  Author(s):Cao, Yu(1,2,3,4); Su, Xiuqin(1); Qian, Xueming(2); Wang, Haitao(1); Hao, Wei(1); Xie, Meilin(1); Feng, Xubin(1); Han, Junfeng(1); Chen, Mingliang(5); Wang, Chenglong(5)
  Source: Remote Sensing  Volume: 14  Issue: 13  DOI: 10.3390/rs14133167  Published: July-1 2022  
  Abstract:In this paper, a tracking and pointing control system with dual-FSM (fast steering mirror) composite axis is proposed. It is applied to the target-tracking accuracy control in a 3D GISC LiDAR (three-dimensional ghost imaging LiDAR via sparsity constraint) system. The tracking and pointing imaging control system of the dual-FSM 3D GISC LiDAR proposed in this paper is a staring imaging method with multiple measurements, which mainly solves the problem of high-resolution remote-sensing imaging of high-speed moving targets when the technology is transformed into practical applications. In the research of this control system, firstly, we propose a method that combines motion decoupling and sensor decoupling to solve the mechanical coupling problem caused by the noncoaxial sensor installation of the FSM. Secondly, we suppress the inherent mechanical resonance of the FSM in the control system. Thirdly, we propose the optical path design of a dual-FSM 3D GISC LiDAR tracking imaging system to solve the problem of receiving aperture constraint. Finally, after sufficient experimental verification, our method is shown to successfully reduce the coupling from 7% to 0.6%, and the precision tracking bandwidth reaches 300 Hz. Moreover, when the dis-tance between the GISC system and the target is 2.74 km and the target flight speed is 7 m/s, the tracking accuracy of the system is improved from 15.7 μrad (σ) to 2.2 μrad (σ), and at the same time, the system recognizes the target contour clearly. Our research is valuable to put the GISC technology into practical applications. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.
  Accession Number: 20222812346284
• Record 463 of
  
  Title:Atmospheric diffuse transmittance of the linear polarization component of water-leaving radiation
  
  Author(s):Pan, Tianfeng(1,2); He, Xianqiang(1,2,3); Bai, Yan(2,3); Liu, Jia(2,4,5); Zhu, Qiankun(2,3); Gong, Fang(2); Li, Teng(2,3); Jin, Xuchen(2,3)
  Source: Optics Express  Volume: 30  Issue: 15  DOI: 10.1364/OE.459666  Published: July 18, 2022  
  Abstract:The polarization characteristics of water-leaving radiation contain rich information on oceanic constituents. Determining the atmospheric diffuse transmittance is crucial for extracting the polarization information of water-leaving radiation from the radiation acquired by polarimetry satellites at the top of the atmosphere. However, there is still a lack of understanding of the atmospheric diffuse transmittance of the linear polarization component of water-leaving radiation. Here, we first evaluated the difference between the atmospheric diffuse transmittance of the linear polarization component (TQ, TU) and the intensity component (TI) of the water-leaving radiation based on the Ocean Successive Orders with Atmosphere Advanced radiative transfer model. As a consequence, there were apparent differences between TQ, TU and TI. In the case of a large solar zenith angle and a large viewing zenith angle, the difference between TQ, TU and TI will exceed 1. Meanwhile, compared with TI, the oceanic constituents had a prominent interference with TQ and TU, and the sediment concentration had little interference with TQ and TU in low- and medium-turbidity water with respect to the aerosol model, optical thickness, observation geometry, and phytoplankton. Moreover, TQ and TU lookup tables were generated for medium- and low-turbidity water, which laid the foundation for extracting the water-leaving radiation polarization information from the satellite observation polarization signal. © 2022 Optica Publishing Group
  Accession Number: 20223012412633
• Record 464 of
  
  Title:Improvements in Brazed-Joint Properties of Silicon Nitride and Titanium Alloys Using Laser-Induced Microscale Rice Leaf Structures
  
  Author(s):He, Jian-Guo(1,2,3); Dai, Shou-Jun(1,3); Zhao, Yang(4); Huang, Min(1,2,3); Liu, Yang(1,3); Yu, Jia-Qi(1,3); Tan, Yu(5); Fan, Lian-Wen(6); Ge, Wen-Qi(1,2); Ma, Yun-Feng(1,2)
  Source: Materials  Volume: 15  Issue: 19  DOI: 10.3390/ma15196750  Published: October 2022  
  Abstract:Si3N4 ceramics with a microscale rice leaf structure (MRLS) and titanium alloy were connected via brazing, and the influence of the surface microstructure on the ceramic connection was analyzed. MRLS fabrication is an efficient and high-degree-of-freedom method that can be used to change a material’s surface morphology and wettability. The MRLS was obtained at a laser power of 110 W, with line spacings of 100 and 50 μm. The laser-treated surface included nanoparticles and micro particles, exhibiting a coral-like structure after agglomeration. When the MRLS was used to braze the titanium alloy, no defects were observed at the brazing interface, and the formation was excellent. Throughout the brazed joint, the MRLS remained intact and formed a strong metallurgical bond with the brazing filler metal. A finite element analysis was performed to study the cross-sectional morphology after joint fracture; from the load-time curve, it was found that the MRLS on the surface not only helped improve the mechanical occlusion and brazing area at the interface, but also helped generate compressive stress on the Si3N4 side. Crack propagation was hindered, thereby increasing the joint strength. © 2022 by the authors.
  Accession Number: 20224212980927
• Record 465 of
  
  Title:Photoswitching the injected energy flux via core-sensitized energy migration upconversion for emission-varying STED microscopy
  
  Author(s):Pu, Rui(1); Liu, Siying(1); Wang, Baoju(1); Zhan, Qiuqiang(1,2,3)
  Source: Optics Letters  Volume: 47  Issue: 18  DOI: 10.1364/OL.464515  Published: September 15, 2022  
  Abstract:Stimulated emission depletion (STED) microscopy achieved with lanthanide-doped upconversion nanoparticles (UCNPs) exhibits many outstanding advantages such as low-power illumination, near-infrared (NIR) excitation, and high photostability. However, the available types of UCNP-STED probes are very limited and rely greatly on the specific depletion mechanism. Here, by combining the STED and the energy migration upconversion processes, emissions of Tb3+, Eu3+, Dy3+, and Sm3+ distributed in the shell can all be depleted by interrupting the injected energy flux from the Tm3+-doped core nanoparticles. With the merit of the proposed strategy, new types of UCNP-STED probes are demonstrated to perform emission-varying STED imaging with one single, fixed pair of low-power NIR continuous wave lasers. © 2022 Optica Publishing Group.
  Accession Number: 20224012831333
• Record 466 of
  
  Title:Large area MCP-PMT design with good time performance
  
  Author(s):Chen, Lin(1); Wang, Xingchao(2,3); He, Jianli(4); Tian, Liping(1); Tian, Jinshou(5); Wang, Yunji(1)
  Source: Optics Express  Volume: 30  Issue: 14  DOI: 10.1364/OE.464209  Published: July 4, 2022  
  Abstract:A new large area photomultiplier tube based on the microchannel plates (MCP-PMT) with high collection efficiency (CE) and good time performance is proposed in this paper. A novel focusing system with two cylindrical and a conical barrels is designed to generate the accelerating and focusing electric field. A three-dimensional model is developed by CST Studio Suite to validate its feasibility. Finite Integral Technique and Monte Carlo method are combined to simulate the process. Results predict that CE of the novel MCP-PMT is expected to be 100%. TTS of the photoelectrons from the whole photocathode achieves 1.2 ns. Differ from other large area PMTs, it performs well in the geomagnetic field. © 2022 Optica Publishing Group
  Accession Number: 20223112464746
• Record 467 of
  
  Title:One-dimensional simulation of Ar dielectric barrier discharge driven by combined rf/dc sources at atmospheric pressure*
  
  Author(s):Qi, Bing(1,2,3,4); Tian, Xiao(5); Wang, Jing(1); Wang, Yi-Shan(1,2); Si, Jin-Hai(3); Tang, Jie(1,2)
  Source: Wuli Xuebao/Acta Physica Sinica  Volume: 71  Issue: 24  DOI: 10.7498/aps.71.20221361  Published: December 20, 2022  
  Abstract:We present the dielectric barrier discharge (DBD) mechanism of argon (Ar) plasma driven by a combination of radio frequency (rf) voltage source and direct current (dc) voltage source at atmospheric pressure, based on one-dimensional self-consistent coupled fluid model. Using the finite element method (FEM) to numerically calculate the model, the average value of period average electron density varying with the average value of period average gas voltage in one rf period, and the variation of the minimum rf sustaining voltage are obtained under different dc voltages. In addition, the spatiotemporal distribution of the electron density and electron generation rate, the spatial distribution of electron temperature, and the time-domain variation of electron conduction current flowing to the dielectric are studied. The results show that the introduction of the dc voltage source has a significant effect on the rf discharge process of atmospheric pressure Ar gas, and the parameters of the plasma state are changed correspondingly. The discharge process is mainly controlled by the air gap voltage, and the dc voltage affects the gap voltage by changing the charge density on the dielectric surface. The minimum rf sustaining voltage Vrf,min first increases and then decreases with the increase of dc voltage. The amplitude of rf minimum sustaining discharge voltage is changed by the dc voltage. And when the amplitude is reached or exceeded, the discharge is controlled by the rf power supply. On the one hand, in the a mode, when the dc voltage is low, electrons are generated near the ground electrode. The electric field intensity in the ionization area is too small to maintain ionization. When the dc voltage is high, the sheath is formed, and electrons are generated near the rf sheaths on both sides and the boundary of the plasma region. In the g mode, when the rf voltage amplitude is equal to or greater than the rf minimum sustain discharge voltage amplitude, i.e. Vrf ≥ Vrf,min, the generation and distribution of electrons are almost unaffected by the dc voltage. On the other hand, in the a mode, the ionization cannot be sustained for the low dc voltage, resulting in the failure to form the main plasma area. Therefore, the electron temperature is generally high. Owing to the high electron density near the ground electrode, the electron temperature is higher. The electron density near the dielectric is less than that near the electrode, so the temperature is lower. When the dc voltage is getting larger, the sheath and the main plasma region are formed. The dc voltage significantly affects the electron temperature by controlling the sheath voltage and the length of the main plasma region. Finally, in the a mode, the electron density near the medium is very low and the air gap voltage is negative for the low dc voltage. As a result, few electrons can reach the surface of the dielectric, and the conduction current of electrons flowing to the medium is very small. With the increase of the dc voltage, the electric field across air gap increases, and electrons, under the action of the electric field, flow from the dielectric surface. The sheath having formed, some speedy non-localization electrons that have reached the dielectric surface are reflected back to the sheath, resulting in a significant reduction in the number of electrons that can reach the dielectric surface. © 2022 Chinese Physical Society.
  Accession Number: 20230213368849
• Record 468 of
  
  Title:A Spatial–Spectral Joint Attention Network for Change Detection in Multispectral Imagery
  
  Author(s):Zhang, Wuxia(1,2,3); Zhang, Qinyu(1); Liu, Shuo(4); Pan, Xiaoying(1); Lu, Xiaoqiang(5)
  Source: Remote Sensing  Volume: 14  Issue: 14  DOI: 10.3390/rs14143394  Published: July 2022  
  Abstract:Change detection determines and evaluates changes by comparing bi-temporal images, which is a challenging task in the remote-sensing field. To better exploit the high-level features, deep-learning-based change-detection methods have attracted researchers’ attention. Most deep-learning-based methods only explore the spatial–spectral features simultaneously. However, we assume the key spatial-change areas should be more important, and attention should be paid to the specific bands which can best reflect the changes. To achieve this goal, we propose the spatial–spectral joint attention network (SJAN). Compared with traditional methods, SJAN introduces the spatial–spectral attention mechanism to better explore the key changed areas and the key separable bands. To be more specific, a novel spatial-attention module is designed to extract the spatially key regions first. Secondly, the spectral-attention module is developed to adaptively focus on the separable bands of land-cover materials. Finally, a novel objective function is proposed to help the model to measure the similarity of learned spatial–spectral features from both spectrum amplitude and angle perspectives. The proposed SJAN is validated on three benchmark datasets. Comprehensive experiments have been conducted to demonstrate the effectiveness of the proposed SJAN. © 2022 by the authors.
  Accession Number: 20223612695604