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Formation of diffuse and spark discharges between two needle electrodes with the scattering of particles

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Plasma Science and Technology 2024年第9期26卷 32-39页

作者： Victor F TARASENKO Dmitry V BELOPLOTOV Alexei N PANCHENKO Dmitry A SOROKIN institute of high current electronics Siberian BranchRussian Academy of SciencesTomsk 634055Russia National Research Tomsk State University Tomsk 634050Russia

The development of a nanosecond discharge in a pin-to-pin gap filled with air at atmospheric pressure has been studied with high temporal and spatial resolutions from a breakdown start to the spark *** and negative nanosecond voltage pulses with an amplitude of tens of kilovolts were ***-resolved images of the discharge development were taken with a fourchannel Intensified Charge Coupled Device(ICCD)*** minimum delay between the camera channels could be as short as≈0.1 *** made it possible to study the gap breakdown process with subnanosecond *** was observed that a wide-diameter streamer develops from the high-voltage pointed *** ionization processes near the grounded pin electrode started when the streamer crossed half of the *** bridging the gap by the streamer,a diffuse discharge was *** development of spark leaders from bright spots on the surface of the pointed electrodes was observed at the next *** was found that the rate of development of the spark leader is an order of magnitude lower than that of the wide-diameter *** thin luminous tracks were observed against the background of a discharge plasma *** has been established that the tracks are adjacent to brightly glowing spots on the electrodes and are associated with the flight of small particles.

关键词： needle electrodes short voltage pulses atmospheric air streamer breakdown diffuse and spark discharges scattering metal particles

A muon high-resolution pseudorange measurement method: Application to muon navigation in confined spaces

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Chinese Journal of Aeronautics 2024年第4期37卷 391-404页

作者： Haoyang LI Chunxi ZHANG Xingming FAN Longjie TIAN Tianqi LI Yang PANG Yanqiang YANG institute of Optics and electronics School of Instrumentation Science and Optoelectronics EngineeringBeihang UniversityBeijing 100191China institute of high Energy Physics Chinese Academy of SciencesBeijing 100049China

Confined spaces such as polar regions, deep earth and deep ocean are crucial navigation scenarios where traditional navigation techniques have difficulty in obtaining external signals for positioning. The cosmic ray muons, which carry the spatial and energetic information, are easy to penetrate these confined spaces. Therefore, the unique muon characteristic provides a new perspective to estimate detector position, which can be considered using in confined spaces *** this paper, a well-developed theory of muon navigation is established by combining a muon pseudorange measurement method. Moreover, an Equivalent Velocity Calculation Model(EVCM)and a Muon Sequence Matching Technology(MSMT) are proposed. The first model corrects flight pseudorange error caused by the relativistic energy loss and the second technology compensates the random error in pseudorange measurement. Further, a series of simulations are performed to analyze the muon events number which can be received by detector in different scenarios with the variations of zenith angle, detector area, varied detector plates gap, and muon flight ***, the simulation results demonstrate that the muon navigation update rate every 10 minutes can reach 5.989 in confined spaces at 100 m, and further pseudorange error analysis indicates that the meter-level positioning accuracy can be acquired. Finally, we construct a muon coincidence measurement scheme and verify that the laws of the muon positioning system for high-energy muons are consistent with the simulation results.

关键词： Muon navigation Cosmic ray muons Muon detection technology Muon transmission technology Pseudorange measurement

Detector performance of the Gamma-ray Transient Monitor onboard DRO-A satellite

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Science China(Physics,Mechanics & Astronomy) 2024年第11期67卷 75-90页

作者： Pei-Yi Feng Zheng-Hua An Da-Li Zhang Chen-Wei Wang Chao Zheng Sheng Yang Shao-Lin Xiong Jia-Cong Liu Xin-Qiao Li Ke Gong Xiao-Jing Liu Min Gao Xiang-Yang Wen Ya-Qing Liu Xiao-Yun Zhao Fan Zhang Xi-Lei Sun Hong Lu Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of Particle Detection and electronics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China

The Gamma-ray Transient Monitor(GTM) is an all-sky monitor onboard the Distant Retrograde Orbit-A(DRO-A) satellite with the scientific objective of detecting gamma-ray transients ranging from 20 ke V to 1 MeV. The GTM was equipped with five Gamma-ray Transient Probe(GTP) detector modules utilizing a NaI(Tl) scintillator coupled with a SiPM array. To reduce the SiPM noise, GTP uses a dedicated dual-channel coincident readout design. In this work, we first studied the impact of different coincidence times on the detection efficiency and ultimately selected a 0.5 μs time coincidence window for offline data processing. To test the performance of the GTPs and validate the Monte-Carlo-simulated energy response, we conducted comprehensive ground calibration tests using the Hard X-ray Calibration Facility(HXCF) and radioactive sources, including the energy response, detection efficiency, spatial response, bias-voltage response, and temperature dependence. We extensively present the ground calibration results and validate the design and mass model of the GTP detector, thus providing the foundation for in-flight observations and scientific data analysis.

关键词： NaI(Tl)detector energy response ground calibration gamma-ray detector DRO-A satellite

Real-time monitoring of oxygenation in deep brain tissue using a wireless photoelectric probe

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Science China Materials 2024年第4期67卷 1361-1362页

作者： Hao Pang Qilin Hua Guozhen Shen School of Integrated Circuits and electronics Beijing Institute of TechnologyBeijing 100084China institute of Flexible electronics Beijing Institute of TechnologyBeijing 102488China

Oxygen(O2) supply to the brain is of utmost importance for human health, as cerebral hypoxia can result in irreversible brain damage. Neurodegenerative diseases, such as epilepsy, are closely associated with cerebral hypoxia [1,2]. Real-time monitoring of cerebral oxygenation holds significant value in neuroscience research and clinical diagnostics [3–10].

关键词： epilepsy cerebral diseases

Tianmouc vision chip designed for open-world sensing

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Science China Materials 2024年第9期67卷 3046-3048页

作者： Haotian Li Qilin Hua Guozhen Shen School of Integrated Circuits and electronics Beijing Institute of TechnologyBeijing100081China institute of Flexible electronics Beijing Institute of TechnologyBeijing102488China

Driven by the forward development of highly interactive applications like autonomous robots and artificial intelligence[1,2],image sensors are continuously demanded to improve in terms of high speed,high resolution,wide dynamic range,and high precision[3].However,due to inherent limitations in power and bandwidth,significant enhancements in one aspect often necessitates compromises in others[4].

关键词： artificial interactive autonomous

Wireless multisite sensing systems for continuous physiological monitoring

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Science China Materials 2024年第6期67卷 2045-2047页

作者： Ruilai Wei Qilin Hua Guozhen Shen School of Integrated Circuits and electronics Beijing Institute of TechnologyBeijing 100081China institute of Flexible electronics Beijing Institute of TechnologyBeijing 102488China

Respiratory diseases rank as the third leading cause of adult mortality[1],while cardiopulmonary and gastrointestinal issues are the primary cause of death within the first five years of a child’s life[2].The monitoring of cardiac,respiratory,and gastrointestinal sounds plays a vital role in routine care,as alterations or absence of these body sounds can serve as indicators of underlying diseases.

关键词： routine continuous monitoring

3D-Printed Monolith Metallic Ni-Mo Electrodes for Ultrahigh current Hydrogen Evolution

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Energy & Environmental Materials 2024年第5期7卷 228-237页

作者： Yanran Xun Hongmei Jin Yuemeng Li Shixiang Zhou Kaixi Zhang Xi Xu Win Jonhson Shuai Chang Teck Leong Tan Jun Ding Department of Materials Science and Engineering National University of Singapore institute of high Performance Computing (IHPC) Agency for Science Technology and Research (ASTAR) Key Laboratory of Flexible electronics of Zhejiang Province Ningbo Institute of Northwestern Polytechnical University State Key Laboratory of Advanced Welding and Joining Harbin Institute of Technology

In this work, we reported a series of monolithic 3D-printed Ni–Mo alloy electrodes for highly efficient water splitting at high current density(1500 mA cm-2) with excellent stability, which provides a solution to scale up Ni–Mo catalysts for HER to industry use. All possible Ni–Mo metal/alloy phases were achieved by tuning the atomic composition and heat treatment procedure, and they were investigated through both experiment and simulation, and the optimal NiMo phase shows the best performance.

关键词： 3D-printed electrode Ni–Mo catalyst phase tuning ultra-high current density HER

Enhanced quality of Al2O3/SiC gate stack via microwave plasma annealing

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Rare Metals 2024年第10期43卷 5362-5371页

作者： Nan-Nan You Xin-Yu Liu Qian Zhang Zhen Wang Jia-Yi Wang Yang Xu Xiu-Yan Li Yu-Zheng Guo Sheng-Kai Wang high-Frequency high-Voltage Device and Integrated Circuits R&D Center Institute of Microelectronics of the Chinese Academy of Sciences School of Integrated Circuits University of Chinese Academy of Sciences School of Electrical Engineering and Automation Wuhan University Department of Micro/Nano electronics School of Electronic Information and Electrical EngineeringShanghai Jiao Tong University

The high-quality gate dielectric on silicon carbide （SiC） surface is critical to fabricate high-performance SiC metal-oxide-semiconductor field-effect transistors（MOSFETs）.This research employs microwave plasma annealing （MPA） to obtain high-quality Al2O3/SiC gate *** designing MPA atmosphere and optimizing the plasma power,the SiC MOS capacitor with a Al2O3dielectric film shows the enhanced *** interface state density is reduced by 1 order of magnitude to 6×1011cm-2·eV-1,the breakdown electric field is increased,and the voltage shift is effectively suppressed Besides,the mechanism of MPA process is discussed in terms of the thermal effect and reactant species.X-ray photoelectron spectroscopy （XPS） results unveil oxygen plasma plays the main *** plasma power during the MPA process results in defect repairs of the firstneighbor Al-O bonding and partial removal of Al-O-H bond from the interface *** study demonstrates that MPA process is an effective option to realize highquality dielectric and interface on SiC.

关键词： Al2O3 Defect repairs Metal–oxide–semiconductor Microwave plasma annealing Silicon carbide X-ray photoelectron spectroscopy

The energy response of LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals for GECAM

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Nuclear Science and Techniques 2024年第2期35卷 110-122页

作者： Pei-Yi Feng Xi-Lei Sun Zheng-Hua An Yong Deng Cheng-Er Wang Huang Jiang Jun-Jie Li Da-Li Zhang Xin-Qiao Li Shao-Lin Xiong Chao Zheng Ke Gong Sheng Yang Xiao-Jing Liu Min Gao Xiang-Yang Wen Ya-Qing liu Yan-Bing Xu Xiao-Yun Zhao Jia-Cong Liu Fan Zhang Hong Lu Particle and Astrophysics Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Key Laboratory of Particle Astrophysics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Experimental Physics Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China State Key Laboratory of Particle Detection and electronics Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Nuclear Science and Technology University of South ChinaHengyang 421001China National Engineering Research Center for Rare Earth Grirem Advanced Materials Co.Ltd.and General Research Institute for Nonferrous MetalsBeijing 100088China

The GECAM series of satellites utilizes LaBr_(3)(Ce),LaBr_(3)(Ce,Sr),and NaI(Tl)crystals as sensitive materials for gamma-ray detectors(GRDs).To investigate the nonlinearity in the detection of low-energy gamma rays and address the errors in the calibration of the E-C relationship,comprehensive tests and comparative studies of the three aforementioned crystals were conducted using Compton electrons,radioactive sources,and mono-energetic *** nonlinearity test results of the Compton electrons and X-rays demonstrated substantial differences,with all three crystals presenting a higher nonlinearity for X/-rays than for Compton *** the LaBr_(3)(Ce)and LaBr_(3)(Ce,Sr)crystals having higher absolute light yields,they exhibited a noticeable nonlinear decrease in the light yield,especially at energies below 400 *** NaI(Tl)crystal demonstrated an"excess"light output in the 6-200 keV range,reaching a maximum"excess"of 9.2%at 30 keV in the X-ray testing and up to 15.5%at 14 keV during Compton electron testing,indicating a significant advantage in the detection of low-energy gamma ***,we explored the underlying causes of the observed nonlinearity in these *** study not only elucidates the detector responses of GECAM,but also initiates a comprehensive investigation of the nonlinearity of domestically produced lanthanum bromide and sodium iodide crystals.

关键词： LaBr_(3)(Ce)detector LaBr_(3)(Ce,Sr)detector NaI(Tl)detector GECAM Energy response Light yield nonlinearity