2024

• Record 289 of
  
  Title:Classification of self-limited epilepsy with centrotemporal spikes by classical machine learning and deep learning based on electroencephalogram data
  
  Author Full Names:Liu, Xi; Zhang, Xinming; Yu, Tao; Dang, Ruochen; Li, Jian; Hu, Bingliang; Wang, Quan; Luo, Rong

  Source Title:BRAIN RESEARCH

  Language:English

  Document Type:Article

  Keywords Plus:BENIGN CHILDHOOD EPILEPSY; NEURAL-NETWORK; EEG CLASSIFICATION; ALGORITHM; CHILDREN

  Abstract:Electroencephalogram (EEG) has been widely utilized as a valuable assessment tool for diagnosing epilepsy in hospital settings. However, clinical diagnosis of patients with self -limited epilepsy with centrotemporal spikes (SeLECTS) is challenging due to the presence of similar abnormal discharges in EEG displays compared to other types of epilepsy (non-SeLECTS) patients. To assist the diagnostic process of epilepsy, a comprehensive classification study utilizing machine learning or deep learning techniques is proposed. In this study, clinical EEG was collected from 33 patients diagnosed with either SeLECTS or non-SeLECTS, aged between 3 and 11 years. In the realm of classical machine learning, sharp wave features (including upslope, downslope, and width at half maximum) were extracted from the EEG data. These features were then combined with the random forest (RF) and extreme random forest (ERF) classifiers to differentiate between SeLECTS and non-SeLECTS. Additionally, deep learning was employed by directly inputting the EEG data into a deep residual network (ResNet) for classification. The classification results were evaluated based on accuracy, F1 -score, area under the curve (AUC), and area under the precision -recall curve (AUPRC). Following a 10 -fold cross -validation, the ERF classifier achieved an accuracy of 73.15 % when utilizing sharp wave feature extraction for classification. The F1 -score obtained was 0.72, while the AUC and AUPRC values were 0.75 and 0.63, respectively. On the other hand, the ResNet model achieved a classification accuracy of 90.49 %, with an F1 -score of 0.90. The AUC and AUPRC values for ResNet were found to be 0.96 and 0.92, respectively. These results highlighted the significant potential of deep learning methods in SeLECTS classification research, owing to their high accuracy. Moreover, feature extraction -based methods demonstrated good reliability and could assist in identifying relevant biological features of SeLECTS within EEG data.

  Addresses:[Liu, Xi; Zhang, Xinming; Dang, Ruochen; Hu, Bingliang; Wang, Quan] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Key Lab Spectral Imaging Technol, Xian, Peoples R China; [Liu, Xi; Zhang, Xinming; Dang, Ruochen] Univ Chinese Acad Sci, Beijing, Peoples R China; [Liu, Xi; Zhang, Xinming; Dang, Ruochen; Hu, Bingliang; Wang, Quan] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Key Lab Biomed Spect Xian, Xian, Peoples R China; [Yu, Tao; Luo, Rong] Sichuan Univ, West China Univ Hosp 2, Dept Pediat, Chengdu, Peoples R China; [Yu, Tao; Luo, Rong] Sichuan Univ, Key Lab Obstet & Gynecol & Pediat Dis & Birth Defe, Minist Educ, Chengdu, Peoples R China; [Li, Jian] Chengdu Univ, Chengdu, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Sichuan University; Sichuan University; Chengdu University

  Publication Year:2024

  Volume:1830

  Article Number:148813

  DOI Link:http://dx.doi.org/10.1016/j.brainres.2024.148813

  数据库ID（收录号）:WOS:001193985400001
• Record 290 of
  
  Title:Singularity engineering of the resonant perfect absorber
  
  Author Full Names:Ming, Xianshun; Ren, Dezheng; Shi, Lei; Sun, Qibing; Sun, Liqun; Wang, Leiran

  Source Title:RESULTS IN PHYSICS

  Language:English

  Document Type:Article

  Keywords Plus:METAMATERIAL; SURFACES; ABSORPTION; DESIGN

  Abstract:The metal-dielectric-metal (MDM) perfect absorber (PA) is an important kind of resonant metasurface with promising applications in selective thermal emitting, solar energy harvesting, biosensing and so on. Establishing a direct link between resonant features and structural parameters is essential for guiding design processes and exploring novel applications. In this paper, we conduct a comprehensive investigation of the MDM PA, utilizing scattering singularity (pole/zero) engineering. We propose a straightforward design methodology to achieve a MDM PA operating at a specific wavelength, and demonstrate a design example with a maximum absorption of 99.93 % at 1200 nm and a full width of half maximum of about 155 nm, which is subsequently experimentally validated. The results indicate high absorption across a wide range of angles. This study sheds new light on fast design and analysis of MDM PAs.

  Addresses:[Ming, Xianshun; Ren, Dezheng; Shi, Lei; Sun, Qibing; Wang, Leiran] Chinese Acad Sci, Xian Inst Opt & Precis Mech XIOPM, State Key Lab Transient Opt & Photon, Xian 710119, Peoples R China; [Ren, Dezheng; Shi, Lei; Sun, Qibing; Wang, Leiran] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Sun, Liqun] Tsinghua Univ, Dept Precis Instruments, State Key Lab Precis Measurement Technol & Instrum, Beijing 100084, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Tsinghua University

  Publication Year:2024

  Volume:58

  Article Number:107500

  DOI Link:http://dx.doi.org/10.1016/j.rinp.2024.107500

  数据库ID（收录号）:WOS:001197121300001
• Record 291 of
  
  Title:Pakistan's 2022 floods: Spatial distribution, causes and future trends from Sentinel-1 SAR observations
  
  Author Full Names:Chen, Fang; Zhang, Meimei; Zhao, Hang; Guan, Weigui; Yang, Aqiang

  Source Title:REMOTE SENSING OF ENVIRONMENT

  Language:English

  Document Type:Article

  Keywords Plus:CLIMATE-CHANGE; RIVER-BASIN; MODEL; VULNERABILITY; COMMUNITIES; DELINEATION; INUNDATION; IMAGES; EXTENT; AREA

  Abstract:Floods are a great threat to Pakistan with increasing concern. As the consequences of increased extreme weather related to climate change, Pakistan experiences severe floods almost every year. This study aims to explore and analysis the actual inundated situation, magnitude, the possible causes of the 2022 devastating floods, and future trends. We presented an enhanced nationwide flood mapping method and compared with other pixel-based image processing techniques including active contours and change detection. These algorithms were applied to Sentinel-1 Ground Range Detected (GRD) Synthetic Aperture Radar (SAR) imagery (10 m spatial resolution) with various land types and inundation scenarios in Pakistan, and were evaluated using other reference flood products. Accuracy evaluation analysis demonstrated that our algorithm has high robustness and accuracy, with the overall accuracy (OA) higher than 0.83 and critical success index (CSI) up to 0.91, and is suitable for automated flood monitoring in near real time. Nearly one-third of the lands were flooded in 2022, and more than half were inundated croplands. Punjab and Sindh provinces were the most severely affected regions, with the proportions of inundated area in 2022 (21.26% and 20.55%) nearly twice of that in 2010 (11.40% and 12.70%), indicating an intensified flooding trend. Analysis of possible influential factors showed that the intense and cumulative rainfall during the monsoon season (June to August) was the major cause of the 2022 flood event. Although the snow melted rapidly in June (the average change in snow depth is similar to 10 mm), the overall ablation contributed insignificant amount to the flood water. The glacial lake outburst floods (GLOFs) induced by abnormal April-May heatwave provide water flowed into the tributaries of the Indus River, but are difficult to spread for thousands of kilometers from mountains to the plain downstream. The combination of the intrinsic arid climate and extreme floods exacerbate the already severe situation.

  Addresses:[Chen, Fang; Zhang, Meimei; Guan, Weigui; Yang, Aqiang] Int Res Ctr Big Data Sustainable Dev Goals, Beijing 100094, Peoples R China; [Chen, Fang; Zhang, Meimei; Guan, Weigui; Yang, Aqiang] Chinese Acad Sci, Aerosp Informat Res Inst, Key Lab Digital Earth Sci, Beijing 100094, Peoples R China; [Chen, Fang; Guan, Weigui] Univ Chinese Acad Sci, Beijing 100049, Peoples R China; [Zhao, Hang] Chinese Acad Sci, Key Lab Spectral Imaging Technol, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China

  Affiliations:Chinese Academy of Sciences; International Research Center of Big Data for Sustainable Development Goals; Chinese Academy of Sciences; Aerospace Information Research Institute, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS

  Publication Year:2024

  Volume:304

  Article Number:114055

  DOI Link:http://dx.doi.org/10.1016/j.rse.2024.114055

  数据库ID（收录号）:WOS:001206388800001
• Record 292 of
  
  Title:Nanosecond pulse X-ray emission source based on ultrafast laser modulation
  
  Author Full Names:Li Yun; Su Tong; Sheng Li-Zhi; Zhang Rui-Li; Liu Duo; Liu Yong-An; Qiang Peng-Fei; Yang Xiang-Hui; Xu Ze-Fang

  Source Title:ACTA PHYSICA SINICA

  Language:Chinese

  Document Type:Article

  Abstract:In response to the growing demand for miniaturized ultrafast pulsed X-ray sources in the fields of fundamental science and space applications, we design and develop an ultrafast pulsed X-ray generator based on a laser-modulated light source and a photoelectric cathode. This innovative technology addresses the limitations commonly encountered in traditional X-ray emission devices, such as low repetition rate, insufficient time stability, and suboptimal pulse characteristics. Our effort is to study and develop the ultrafast modulation control module for the pulsed X-ray generator. This effort results in achieving high levels of time accuracy and stability in ultrafast time-varying photon signals. Moreover, we successfully generate nanosecond pulsed X-rays by using a laser-controlled light source. Theoretically, we establish a comprehensive time response model for the pulsed X-ray generator in response to short pulses. This includes a thorough analysis of the time characteristics of the emitted pulsed X-rays in the time domain. Experimentally, we conduct a series of tests related to various time-related parameters of the laser-controlled light source. Additionally, we design and implemente an experimental test system for assessing the time characteristics of pulsed X-rays, by using an ultrafast scintillation detector. The experimental results clearly demonstrate that our pulsed X-ray generator achieves impressive capabilities, including high repetition rates (12.5 MHz), ultrafast pulses (4 ns), and exceptional time stability (400 ps) in X-ray emission. These results closely align with our established theoretical model. Compared with traditional modulation techniques, our system exhibits significant improvement in pulse time parameters, thereby greatly expanding its potential applications. This research provides a valuable insight into achieving ultra-high time stability and ultrafast pulsed X-ray emission sources. These advances will further enhance the capabilities of X-ray technology for scientific research and space applications.

  Addresses:[Li Yun; Su Tong; Sheng Li-Zhi; Zhang Rui-Li; Liu Yong-An; Qiang Peng-Fei; Yang Xiang-Hui; Xu Ze-Fang] Xian Inst Opt & Precis Mech, State Key Lab Transient Opt & Photon, Xian 710119, Peoples R China; [Li Yun; Xu Ze-Fang] Univ Chinese Acad Sci, Sch Optoelect, Beijing 100049, Peoples R China; [Liu Duo] Handan Univ, Sch Math & Phys, Handan 056005, Peoples R China

  Affiliations:State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; Handan University

  Publication Year:2024

  Volume:73

  Issue:4

  Article Number:40701

  DOI Link:http://dx.doi.org/10.7498/aps.73.20231505

  数据库ID（收录号）:WOS:001193604800010
• Record 293 of
  
  Title:Tetherless Optical Neuromodulation: Wavelength from Orange-red to Mid-infrared
  
  Author Full Names:Sun, Chao; Fan, Qi; Xie, Rougang; Luo, Ceng; Hu, Bingliang; Wang, Quan

  Source Title:NEUROSCIENCE BULLETIN

  Language:English

  Document Type:Review

  Keywords Plus:UP-CONVERSION NANOPARTICLES; ION-CHANNEL; PHOTOTHERMAL THERAPY; VISUAL PIGMENTS; BRAIN-TISSUE; ACTIVATION; TRPV1; OPTOGENETICS; EXCITATION; LIGHT

  Abstract:Optogenetics, a technique that employs light for neuromodulation, has revolutionized the study of neural mechanisms and the treatment of neurological disorders due to its high spatiotemporal resolution and cell-type specificity. However, visible light, particularly blue and green light, commonly used in conventional optogenetics, has limited penetration in biological tissue. This limitation necessitates the implantation of optical fibers for light delivery, especially in deep brain regions, leading to tissue damage and experimental constraints. To overcome these challenges, the use of orange-red and infrared light with greater tissue penetration has emerged as a promising approach for tetherless optical neuromodulation. In this review, we provide an overview of the development and applications of tetherless optical neuromodulation methods with long wavelengths. We first discuss the exploration of orange-red wavelength-responsive rhodopsins and their performance in tetherless optical neuromodulation. Then, we summarize two novel tetherless neuromodulation methods using near-infrared light: upconversion nanoparticle-mediated optogenetics and photothermal neuromodulation. In addition, we discuss recent advances in mid-infrared optical neuromodulation.

  Addresses:[Sun, Chao; Fan, Qi; Wang, Quan] Chinese Acad Sci, Xian Inst Opt & Precis Mech XIOPM, Key Lab Spectral Imaging Technol, Xian 710119, Peoples R China; [Sun, Chao; Fan, Qi; Hu, Bingliang; Wang, Quan] Chinese Acad Sci, Key Lab Biomed Spect Xian, Key Lab Spectral Imaging Technol, XIOPM, Xian 710119, Peoples R China; [Xie, Rougang; Luo, Ceng] Fourth Mil Med Univ, Sch Basic Med, Dept Neurobiol, Xian 710032, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; Air Force Military Medical University

  Publication Year:2024

  Volume:40

  Issue:8

  Start Page:1173

  End Page:1188

  DOI Link:http://dx.doi.org/10.1007/s12264-024-01179-1

  数据库ID（收录号）:WOS:001164917600002
• Record 294 of
  
  Title:All-optical neural network nonlinear activation function based on the optical bistability within a micro-ring resonator
  
  Author Full Names:Zhang, Hui; Wen, Jin; Wu, Zhengwei; Wang, Qian; Yu, Huimin; Zhang, Ying; Pan, Yu; Yin, Lan; Wang, Chenglong; Qu, Shuangchao

  Source Title:OPTICS COMMUNICATIONS

  Language:English

  Document Type:Article

  Keywords Plus:ABSORPTION

  Abstract:Training all-optical neural networks in itself remains an unresolved problem, and the challenges compound when the problem is turned into the hardware implementations. In this paper, we propose a nonlinear activation function based on optical bistability within a micro-ring resonator (MRR), achieving threshold control without external modulation. Furthermore, a convolutional neural network similar to the Le-Net-5 architecture is designed, in which all nonlinear activation functions are composed of optical bistable hysteresis loop. The numerical simulation results demonstrate that the recognition rate on the Fashion-MNIST dataset can achieve 91.3%, which means that the optical neuromorphic computation can be implemented by utilizing the nonlinear optical effects themselves in the all-optical hardware. Such a scheme promises access to the all-optical neural network training in the optical hardware environment compared to numerical activation functions.

  Addresses:[Zhang, Hui; Wen, Jin; Wu, Zhengwei; Wang, Qian; Yu, Huimin; Zhang, Ying; Pan, Yu; Yin, Lan; Wang, Chenglong; Qu, Shuangchao] Xian Shiyou Univ, Sch Sci, Xian 710065, Peoples R China; [Wen, Jin] Chinese Acad Sci, Xian Inst Opt & Precis Mech, State Key Lab Transient Opt & Photon, Xian 710119, Peoples R China

  Affiliations:Xi'an Shiyou University; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS

  Publication Year:2024

  Volume:558

  Article Number:130374

  DOI Link:http://dx.doi.org/10.1016/j.optcom.2024.130374

  数据库ID（收录号）:WOS:001197464800001
• Record 295 of
  
  Title:Iodide-based glass with combination of high transparency and conductivity: A novel promising candidate for transparent microwave absorption and radar stealth
  
  Author Full Names:Guo, Chen; Chen, Chao; Wan, Rui; Yang, Liqing; Guan, Yongmao; Wang, Pengfei

  Source Title:CHEMICAL ENGINEERING JOURNAL

  Language:English

  Document Type:Article

  Keywords Plus:OPTICALLY-TRANSPARENT; ELECTRICAL-PROPERTIES; ABSORBER; COMPOSITE; BAND; CONSTRUCTION; FREQUENCY; SPECTRA

  Abstract:The rapid development of the electronics industry has sparked widespread interest in transparent microwave-absorbing materials. Herein, iodide-based transparent conductive glass was used as a candidate material for transparent microwave absorption. AgI-AgPO3-WO3 glasses with varying AgI content were synthesized employing a quench-melting method. Their structures, optical and electrical properties, microwave absorption performance, and radar cross section (RCS) reduction were thoroughly investigated. The 45AgI-45AgPO(3)-10WO(3) sample exhibited satisfactory microwave absorption, achieving a minimum reflection loss (RLmin) of - 47.18 dB, effective absorption bandwidth (EAB) of 1.97 GHz, and RCS reduction of 31.46 dB m(2) in the X band. This was attributed to the synergistic effects of dielectric and magnetic losses, and impedance matching and electromagnetic attenuation. It also manifested acceptable performance in the Ku band (RLmin = - 14.58 dB, EAB = 1.38 GHz, and RCS reduction = 13.37 dB m(2)), which was primarily attributed to dielectric loss and electromagnetic attenuation. The conductive glass exhibited an optical transmittance of similar to 80 % in the range of 500-2000 nm. In summary, this study highlights the potential use of transparent conductive glasses as transparent microwave-absorbing media for electromagnetic interference shielding applications in optical windows and domes, and stealth applications in high-performance optical cameras and optical detection device systems.

  Addresses:[Guo, Chen; Chen, Chao; Wan, Rui; Yang, Liqing; Guan, Yongmao; Wang, Pengfei] Chinese Acad Sci, Xian Inst Opt & Precis Mech, State Key Lab Transient Opt & Photon, Xian 710119, Shaanxi, Peoples R China; [Guo, Chen; Wan, Rui; Guan, Yongmao; Wang, Pengfei] Univ Chinese Acad Sci, Ctr Mat Sci & Optoelect Engn, Beijing 100049, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS

  Publication Year:2024

  Volume:484

  Article Number:148930

  DOI Link:http://dx.doi.org/10.1016/j.cej.2024.148930

  数据库ID（收录号）:WOS:001188661300001
• Record 296 of
  
  Title:Spectral encoder to extract the efficient features of Raman spectra for reliable and precise quantitative analysis
  
  Author Full Names:Gao, Chi; Fan, Qi; Zhao, Peng; Sun, Chao; Dang, Ruochen; Feng, Yutao; Hu, Bingliang; Wang, Quan

  Source Title:SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY

  Language:English

  Document Type:Article

  Keywords Plus:SPECTROSCOPY; IDENTIFICATION; MIXTURES; TOOLS

  Abstract:Raman spectroscopy has become a powerful analytical tool highly demanded in many applications such as microorganism sample analysis, food quality control, environmental science, and pharmaceutical analysis, owing to its non-invasiveness, simplicity, rapidity and ease of use. Among them, quantitative research using Raman spectroscopy is a crucial application field of spectral analysis. However, the entire process of quantitative modeling largely relies on the extraction of effective spectral features, particularly for measurements on complex samples or in environments with poor spectral signal quality. In this paper, we propose a method of utilizing a spectral encoder to extract effective spectral features, which can significantly enhance the reliability and precision of quantitative analysis. We built a latent encoded feature regression model; in the process of utilizing the autoencoder for reconstructing the spectrometer output, the latent feature obtained from the intermediate bottleneck layer is extracted. Then, these latent features are fed into a deep regression model for component concentration prediction. Through detailed ablation and comparative experiments, our proposed model demonstrates superior performance to common methods on single -component and multicomponent mixture datasets, remarkably improving regression precision while without needing user -selected parameters and eliminating the interference of irrelevant and redundant information. Furthermore, in-depth analysis reveals that latent encoded feature possesses strong nonlinear feature representation capabilities, low computational costs, wide adaptability, and robustness against noise interference. This highlights its effectiveness in spectral regression tasks and indicates its potential in other application fields. Sufficient experimental results show that our proposed method provides a novel and effective feature extraction approach for spectral analysis, which is simple, suitable for various methods, and can meet the measurement needs of different real -world scenarios.

  Addresses:[Gao, Chi; Fan, Qi; Zhao, Peng; Sun, Chao; Dang, Ruochen; Feng, Yutao; Hu, Bingliang; Wang, Quan] Chinese Acad Sci, Key Lab Spectral Imaging Technol, Xian Inst Opt & Precis Mech, Xian 710076, Shaanxi, Peoples R China; [Gao, Chi; Fan, Qi; Zhao, Peng; Sun, Chao; Dang, Ruochen; Feng, Yutao; Hu, Bingliang; Wang, Quan] Key Lab Biomed Spect Xian, Xian 710076, Shaanxi, Peoples R China; [Gao, Chi; Zhao, Peng; Dang, Ruochen] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS

  Publication Year:2024

  Volume:312

  Article Number:124036

  DOI Link:http://dx.doi.org/10.1016/j.saa.2024.124036

  数据库ID（收录号）:WOS:001187724700001
• Record 297 of
  
  Title:Performance improvement of a discrete dynode electron multiplication system through the optimization of secondary electron emitter and the adoption of double-grid dynode structure
  
  Author Full Names:Liu, Biye; Li, Jie; Chen, Song; Yang, Jishi; Hu, Wenbo; Tian, Jinshou; Wu, Shengli

  Source Title:NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT

  Language:English

  Document Type:Article

  Keywords Plus:EMISSION; MGO/AU

  Abstract:The discrete dynode electron multiplication system (DD-EMS) is the core part of commonly used photomultiplier tubes and electron multipliers, and it has a great influence on the signal amplification capability of these devices. In this work, the sputtering time of Mg target during the deposition of the surface MgO layer of the MgO/ (MgO-Au)/Au multilayer film as the secondary electron emitter was optimized, and the strategy of double-grid structures applied at the 7th and 8th dynodes was proposed with the intention of improving the gain and stability of nine-stage DD-EMS under electron bombardment to satisfy the requirements of detecting the single photon or single charged particle. The investigation results show that the DD-EMS fabricated by using the MgO/(MgO-Au)/ Au film with a Mg target's sputtering time of 3600 s has the highest maximal gain of 1.22 x 106 and the lowest gain attenuation rate of 15.7%/mC under electron bombardment. In addition, the DD-EMS with the double-grid structure has a higher maximal gain of 1.62 x 106 and a lower gain attenuation rate of 11.6%/mC under continuous electron bombardment, which are 32.8% increased and 17.7% reduced respectively in comparison with that of the single-grid structure.

  Addresses:[Liu, Biye; Li, Jie; Yang, Jishi; Hu, Wenbo; Wu, Shengli] Xi An Jiao Tong Univ, Sch Elect Sci & Engn, Key Lab Phys Elect & Devices, Minist Educ, Xian 710049, Peoples R China; [Liu, Biye] Beijing Orient Inst Measurement & Test, Beijing 100086, Peoples R China; [Chen, Song] China Telecom Corp Ltd, Beijing Res Inst, Beijing 102209, Peoples R China; [Tian, Jinshou] Chinese Acad Sci, Xian Inst Opt & Precis Mech XIOPM, Key Lab Ultrafast Photoelect Diagnost Technol, Xian 710119, Peoples R China

  Affiliations:Xi'an Jiaotong University; China Telecom Corp. Ltd.; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS

  Publication Year:2024

  Volume:1062

  Article Number:169162

  DOI Link:http://dx.doi.org/10.1016/j.nima.2024.169162

  数据库ID（收录号）:WOS:001188013500001
• Record 298 of
  
  Title:Random laser emission at 1064 and 1550 nm in a Er/Yb co-doped fiber-based dual-wavelength random fiber laser
  
  Author Full Names:Li, Zhe; She, Shengfei; Li, Gang; Gao, Qi; Ju, Pei; Gao, Wei; Sun, Chuandong; Wang, Yishan

  Source Title:OPTICS EXPRESS

  Language:English

  Document Type:Article

  Keywords Plus:POWER; LINEWIDTH

  Abstract:Dual-wavelength fiber lasers operating with a wide spectral separation are of considerable importance for many applications. In this study, we propose and experimentally explore an all-fiberized dual-wavelength random fiber laser with bi-directional laser output operating at 1064 and 1550 nm, respectively. A specially designed Er/Yb co-doped fiber, by optimizing the concentrations of the co-doped Er, Yb, Al and P, was developed for simultaneously providing Er ions gain and Yb ions gain for RFL. Two spans of single mode passive fibers are employed to providing random feedback for 1064 and 1550 nm random lasing, respectively. The RFL generates 5.35 W at 1064 nm and 6.61 W at 1550 nm random lasers. Two power amplifiers (PA) enhance the seed laser to 50 W at 1064 nm with a 3 dB bandwidth of 0.31 nm and 20 W at 1550 nm with a 3 dB bandwidth of 1.18 nm. Both the short- and long-term time domain stabilities are crucial for practical applications. The output lasers of 1064 and 1550 nm PAs are in the single transverse mode operating with a nearly Gaussian profile. To the best of our knowledge, this is the first demonstration of a dual-wavelength RFL, with a spectral separation as far as about 500 nm in an all -fiber configuration.

  Addresses:[Li, Zhe; Gao, Qi; Ju, Pei; Sun, Chuandong; Wang, Yishan] Chinese Acad Sci, State Key Lab Transient Opt & Photon, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Li, Zhe; Gao, Qi; Ju, Pei; Wang, Yishan] Univ Chinese Acad Sci, Beijing 100049, Peoples R China

  Affiliations:Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; State Key Laboratory of Transient Optics & Photonics; Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS

  Publication Year:2024

  Volume:32

  Issue:4

  Start Page:5737

  End Page:5747

  DOI Link:http://dx.doi.org/10.1364/OE.508025

  数据库ID（收录号）:WOS:001208575800007
• Record 299 of
  
  Title:Snapshot compressive imaging at 855 million frames per second for aluminium planar wire array Z-pinch
  
  Author Full Names:Yao, Zhiming; Ji, Chao; Sheng, Liang; Song, Yan; Liu, Zhen; Han, Changcai; Zhou, Haoyu; Duan, Baojun; Li, Yang; Hei, Dongwei; Tian, Jinshou; Xue, Yanhua

  Source Title:OPTICS EXPRESS

  Language:English

  Document Type:Article

  Keywords Plus:ULTRAFAST PHOTOGRAPHY

  Abstract:This paper present a novel, integrated compressed ultrafast photography system for comprehensive measurement of the aluminium planar wire array Z-Pinch evolution process. The system incorporates a large array streak camera and embedded encoding to improve the signal-to-noise ratio. Based on the QiangGuang-I pulsed power facility, we recorded the complete continuous 2D implosion process of planar wire array Z-Pinch for the first time. Our results contribute valuable understanding of imploding plasma instabilities and offer direction for the optimization of Z-Pinch facilities.

  Addresses:[Yao, Zhiming; Sheng, Liang; Song, Yan; Liu, Zhen; Han, Changcai; Zhou, Haoyu; Duan, Baojun; Li, Yang; Hei, Dongwei] Northwest Inst Nucl Technol, Natl Key Lab Intense Pulsed Radiat Simulat & Effec, Xian 710024, Peoples R China; [Ji, Chao; Tian, Jinshou; Xue, Yanhua] Chinese Acad Sci, Key Lab Ultrafast Photoelect Diagnost Technol, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Zhou, Haoyu] Tsinghua Univ, Dept Engn Phys, Beijing 100085, Peoples R China

  Affiliations:Northwest Institute of Nuclear Technology - China; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Tsinghua University

  Publication Year:2024

  Volume:32

  Issue:4

  Start Page:6567

  End Page:6574

  DOI Link:http://dx.doi.org/10.1364/OE.512450

  数据库ID（收录号）:WOS:001208895500004
• Record 300 of
  
  Title:Feasible spindle speed interval identification method for large aeronautical component robotic milling system
  
  Author Full Names:Wang, Zhanxi; Zhang, Banghai; Gao, Wei; Qin, Xiansheng; Zhang, Yicha; Zheng, Chen

  Source Title:MECHATRONICS

  Language:English

  Document Type:Article

  Keywords Plus:CHATTER SUPPRESSION; INDUSTRIAL ROBOT; STABILITY; OPTIMIZATION

  Abstract:Robotic machining systems have been widely implemented in the assembly sites of large components of aircraft, such as wings, aircraft engine rooms, and wing boxes. Milling is the first step in aircraft assembly. It is considered one of the most significant processes because the quality of the subsequent drilling, broaching, and riveting steps depend strongly on the milling accuracy. However, the chatter phenomenon may occur during the milling process because of the low rigidity of the components of the robotic milling system (i.e., robots, shape-preserving holders, and rod parts). This may result in milling failure or even fracture of the robotic milling system. This paper presents a feasible spindle speed interval identification method for large aeronautical component milling systems to eliminate the chatter phenomenon. It is based on the chatter stability model and the analysis results of natural frequency and harmonic response. Firstly, the natural frequencies and harmonics of the main components of the robot milling system are analyzed, and the spindle speed that the milling system needs to avoid is obtained. Then, a flutter stability model considering the instantaneous cutting thickness is established, from which the critical cutting depth corresponding to the spindle speed can be obtained. Finally, the spindle speed interval of the robotic milling system could be optimized based on the results obtained from the chatter stability model and the analysis result of the natural frequency and harmonic response of the milling system. The effectiveness of the proposed spindle speed interval identification method is validated through time-domain simulation and experimental results of the large aeronautical component milling system.

  Addresses:[Wang, Zhanxi; Zhang, Banghai; Qin, Xiansheng; Zheng, Chen] Northwestern Polytech Univ, Sch Mech Engn, Xian 710072, Peoples R China; [Gao, Wei] Chinese Acad Sci, Xian Inst Opt & Precis Mech, Xian 710119, Peoples R China; [Zhang, Yicha] Univ Technol Belfort Montbeliard, Univ Bourgogne Franche Comte, Mech Engn & Design Dept, ICB UMR CNRS 6303, F-90010 Belfort, France

  Affiliations:Northwestern Polytechnical University; Chinese Academy of Sciences; Xi'an Institute of Optics & Precision Mechanics, CAS; Universite de Technologie de Belfort-Montbeliard (UTBM); Universite de Franche-Comte; Universite de Bourgogne

  Publication Year:2024

  Volume:99

  Article Number:103143

  DOI Link:http://dx.doi.org/10.1016/j.mechatronics.2024.103143

  数据库ID（收录号）:WOS:001183320600001