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Atomic magnetometer with microfabricated vapor cells based on coherent population trapping

Chinese Physics B 2021年第3期30卷 215-219页

作者： Xiaojie Li Yue Shi Hongbo Xue Yong Ruan Yanying Feng State Key Laboratory of Precision Measurement Technology and Instrument Tsinghua UniversityBeijing 100084China Key Laboratory of Photonic Control Technology(Ministry of Education) Tsinghua UniversityBeijing 100084China Department of Precision Instrument Tsinghua UniversityBeijing 100084China State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190China MEMS Institute of Zibo National High-tech Industrial Development Zone Zibo 255086China

An atomic magnetometer based on coherent population trapping(CPT) resonances in microfabricated vapor cells is demonstrated. Fabricated by the micro-electro-mechanical-system(MEMS) technology, the cells are filled with Rb and Ne at a controlled pressure. An experimental apparatus is built for characterizing properties of microfabricated vapor cells via the CPT effects. The typical CPT linewidth is measured to be about 3 k Hz(1.46 k Hz with approximately zero laser intensity) for the rubidium D1 line at about 90℃. The effects of pressure, temperature and laser intensity on CPT linewidth are studied experimentally. A closed-loop atomic magnetometer is finally finished with a sensitivity of 210.5 p T/Hz1/2 at 1 Hz bandwidth. This work paves the way for developing an integrated chip-scale atomic magnetometer in the future.

关键词： atomic magnetometer MEMS vapor cell coherent population trapping

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The 2022 report of synergetic roadmap on carbon neutrality and clean air for China:Accelerating transition in key sectors

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Environmental Science and Ecotechnology 2024年第3期19卷 4-18页

作者： Yu Lei Zhicong Yin Xi Lu Qiang Zhang Jicheng Gong Bofeng Cai Cilan Cai Qimin Chai Huopo Chen Renjie Chen Shi Chen Wenhui Chen Jing Cheng Xiyuan Chi Hancheng Dai Xiangzhao Feng Guannan Geng Jianlin Hu Shan Hu Cunrui Huang Tiantian Li Wei Li Xiaomei Li Jun Liu Xin Liu Zhu Liu Jinghui Ma Yue Qin Dan Tong Xuhui Wang Xuying Wang Rui Wu Qingyang Xiao Yang Xie Xiaolong Xu Tao Xue Haipeng Yu Da Zhang Ning Zhang Shaohui Zhang Shaojun Zhang Xian Zhang Xin Zhang Zengkai Zhang Bo Zheng Yixuan Zheng Jian Zhou Tong Zhu Jinnan Wang Kebin He Center of Air Quality Simulation and System Analysis Chinese Academy of Environmental PlanningBeijing100041China Center for Carbon Neutrality Chinese Academy of Environmental PlanningBeijing100041China Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing210044China State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing100084China Institute for Carbon Neutrality Tsinghua UniversityBeijing100084China Ministry of Education Key Laboratory for Earth System Modelling Department of Earth System ScienceTsinghua UniversityBeijing100084China State Key Joint Laboratory for Environment Simulation and Pollution Control College of Environmental Sciences and Engineering and Center for Environment and HealthPeking UniversityBeijing100871China National Center for Climate Change Strategy and International CooperationBeijing100035China Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100029China School of Public Health Key Lab of Public Health Safety of the Ministry of Education and Key Lab of Health Technology Assessment of the Ministry of HealthFudan UniversityShanghai200032China School of Economics and Management Beijing University of Chemical TechnologyBeijing100029China Department of Earth System Science University of CaliforniaIrvineCA92697USA National Meteorological Center China Meteorological AdministrationBeijing100081China College of Environmental Sciences and Engineering Peking UniversityBeijing100871China Policy Research Center for Environment and Economy Ministry of Ecology and Environment of the People's Republic of ChinaBeijing100029China Jiangsu Key Laboratory of Atmospheric Environment Monitoring

China is now confronting the intertwined challenges of air pollution and climate *** the high synergies between air pollution abatement and climate change mitigation,the Chinese government is actively promoting synergetic control of these two *** Synergetic Roadmap project was launched in 2021 to track and analyze the progress of synergetic control in China by developing and monitoring key *** Synergetic Roadmap 2022 report is the first annual update,featuring 20 indicators across five aspects:synergetic governance system and practices,progress in structural transition,air pollution and associated weather-climate interactions,sources,sinks,and mitigation pathway of atmospheric composition,and health impacts and benefits of coordinated *** to the comprehensive review presented in the 2021 report,the Synergetic Roadmap 2022 report places particular emphasis on progress in 2021 with highlights on actions in key sectors and the relevant *** milestones include the proportion of non-fossil power generation capacity surpassing coal-fired capacity for the first time,a decline in the production of crude steel and cement after years of growth,and the surging penetration of electric ***,in 2022,China issued the first national policy that synergizes abatements of pollution and carbon emissions,marking a new era for China's pollution-carbon *** changes highlight China's efforts to reshape its energy,economic,and transportation structures to meet the demand for synergetic control and sustainable ***,the country has witnessed a slowdown in carbon emission growth,improved air quality,and increased health benefits in recent years.

关键词： Synergetic roadmap Carbon neutrality Clean air

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Second harmonic generation of laser beams in transverse mode locking states

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Advanced Photonics 2022年第2期4卷 68-77页

作者： Zilong Zhang Yuan Gao Xiangjia Li Xin Wang Suyi Zhao Qiang Liu Changming Zhao Beijing Institute of Technology School of Optics and PhotonicsBeijingChina Ministry of Education Key Laboratory of Photoelectronic Imaging Technology and SystemBeijingChina Ministry of Industry and Information Technology Key Laboratory of Photonics Information TechnologyBeijingChina Arizona State University School for Engineering of MatterTransport and EnergyDepartment of Aerospace and Mechanical EngineeringTempeArizonaUnited States Ministry of Education Key Laboratory of Photonic Control Technology(Tsinghua University)BeijingChina Tsinghua University Department of Precision InstrumentState Key Laboratory of Precision Measurement Technology and InstrumentsBeijingChina

Nonlinear frequency conversion of structured beams has been of great interest *** present an intracavity second harmonic generation(SHG)of laser beams in transverse mode locking(TML)states with a specially designed sandwich such as a microchip *** intracavity nonlinear frequency conversion process of a laser beam in a TML state to its second harmonic is theoretically and experimentally investigated,considering different relative phase and weight parameters between the basic modes in the TML *** between the far-field SHG beam patterns of fundamental frequency transverse modes in coherently locked and incoherently superposed states demonstrates that the SHG of TML beams can carry more *** rarely observed far-field SHG beam patterns are obtained,and they are consistent with the theoretical analysis and numerical *** the obtained SHG beams,the characteristics of the structured fundamental frequency beams can also be conversely investigated or *** work may have important applications in optical 3D printing,optical trapping of particles,and free-space optical communication areas.

关键词： transverse mode locking optical vortex lattice structured beams second harmonic generation

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Evolution on spatial patterns of structured laser beams:from spontaneous organization to multiple transformations

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Advanced Photonics Nexus 2023年第2期2卷 1-22页

作者： Xin Wang Zilong Zhang Xing Fu Adnan Khan Suyi Zhao Yuan Gao Yuchen Jie Wei He Xiaotian Li Qiang Liu Changming Zhao Beijing Institute of Technology School of Optics and PhotonicsBeijingChina Ministry of Education Key Laboratory of Photoelectronic Imaging Technology and SystemBeijingChina Ministry of Industry and Information Technology Key Laboratory of Photonics Information TechnologyBeijingChina Tsinghua University Ministry of EducationKey Laboratory of Photonic Control TechnologyBeijingChina Tsinghua University State Key Laboratory of Precision Measurement Technology and InstrumentsDepartment of Precision InstrumentBeijingChina Nankai University School of PhysicsKey Laboratory of Weak Light Nonlinear PhotonicsTianjinChina

Spatial patterns are a significant characteristic of *** knowledge of spatial patterns of structured laser beams is rapidly expanding,along with the progress of studies on laser physics and tech*** in the last decades,owing to the in-depth attention on structured light with multiple degrees of freedom,the research on spatial and spatiotemporal structures of laser beams has been promptly *** beams have hatched various breakthroughs in many fields,including imaging,microscopy,metrology,communication,optical trapping,and quantum information ***,we would like to provide an overview of the extensive research on several areas relevant to spatial patterns of structured laser beams,from spontaneous organization to multiple *** include the early theory of beam pattern formation based on the Maxwell–Bloch equations,the recent eigenmodes superposition theory based on the time-averaged Helmholtz equations,the beam patterns extension of ultrafast lasers to the spatiotemporal beam structures,and the structural transformations in the nonlinear frequency conversion process of structured beams.

关键词： spatial patterns transverse modes spatiotemporal beams structured laser beams nonlinear optics

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Application of automated laser seam tracking straight seam welding technology in production

Application of automated laser seam tracking straight seam w...

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2024 International Conference on Precision Instruments and Optical Engineering, PIOE 2024

作者： Qin, Jingchuan Liu, Yongkai Hu, Haoran Liu, Xian Beijing AriTime Intelligent Control Co. Ltd. 6 Fufeng Road Fengtai District Beijing Science and Technology Park Beijing100070 China Automation Research And Design Institute Of Metallurgical Industry Co. LTD. 72 South Fourth Ring Road Fengtai District Beijing100070 China National Key Laboratory of Metallurgical Intelligent Manufacturing System Beijing100081 China Shanxi Limin Industrial Co. Ltd. TaiGu030812 China

ISBN: (纸本)9781510686120

In the manufacturing process of a specific type of conical cylinder, high-frequency argon arc welding is employed for butt welding. The uncertainty of the butt weld position relative to the welding gun results in excessive manual labor during production, leading to suboptimal product qualification rates;Consequently, the implementation of a fusion laser welding seam tracking automated control system was initiated. This system utilizes a PLC to gather various sensor data signals, control servomotors, valves, and motors, thereby establishing a comprehensive automated butt welding tracking control system. Ultimately, this achieves the goals of reducing labor costs, diminishing labor intensity, and enhancing both production efficiency and product quality. © 2024 SPIE.

关键词： Butt welding

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A New Image Quality Database for Multiple industrial processes

arXiv

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arXiv 2024年

作者： Ma, Xuanchao Jiang, Yanlin Liu, Hongyan Zhou, Chengxu Gu, Ke Faculty of Information Technology Beijing University of Technology Beijing China Engineering Research Center of Intelligent Perception and Autonomous Control Ministry of Education Beijing Laboratory of Smart Environmental Protection China Beijing Key Laboratory of Computational Intelligence and Intelligent System China Beijing Artificial Intelligence Institute China School of Electronic & Information Engineering Liaoning University of Technology Liaoning China Key Laboratory of Intelligent Control and Optimization for Industrial Equipment of Ministry of Education Dalian University of Technology China

Recent years have witnessed a broader range of applications of image processing technologies in multiple industrial processes, such as smoke detection, security monitoring, and workpiece inspection. Different kinds of distortion types and levels must be introduced into an image during the processes of acquisition, compression, transmission, storage, and display, which might heavily degrade the image quality and thus strongly reduce the final display effect and clarity. To verify the reliability of existing image quality assessment methods, we establish a new industrial process image database (IPID), which contains 3000 distorted images generated by applying different levels of distortion types to each of the 50 source images. We conduct the subjective test on the aforementioned 3000 images to collect their subjective quality ratings in a well-suited laboratory environment. Finally, we perform comparison experiments on IPID database to investigate the performance of some objective image quality assessment algorithms. The experimental results show that the state-of-the-art image quality assessment methods have difficulty in predicting the quality of images that contain multiple distortion types. Copyright © 2024, The Authors. All rights reserved.

关键词： Database systems

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A compensation method for the packet loss deviation in system identification with event-triggered binary-valued observations

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Science China(Information Sciences) 2020年第12期63卷 266-268页

作者： Jing-Dong DIAO Jin GUO Changyin SUN School of Automation and Electrical Engineering University of Science and Technology Beijing Key Laboratory of Knowledge Automation for Industrial Processes Ministry of Education School of Automation Southeast University Key Laboratory of Measurement and Control of Complex System of Engineering Ministry of Education

Dear editor,With the rapid development of network and communication technology, group systems interrelated in terms of both time and space are commonly encountered, such as sensor networks, multi-agent systems, and sm... 详细信息

关键词： system identification event-triggered binary-valued observations packet loss convergence

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A new anterograde trans-synaptic tracer based on Sindbis virus

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Neural Regeneration Research 2022年第12期17卷 2761-2764页

作者： Xiang-Wei Shi Fan Jia Pei Lyu Fu-Qiang Xu State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics Key Laboratory of Magnetic Resonance in Biological SystemsWuhan Center for Magnetic ResonanceInnovation Academy for Precision Measurement Science and TechnologyChinese Academy of SciencesWuhanHubei ProvinceChina Guangdong Provincial Key Laboratory of Brain Connectome and Behavior CAS Key Laboratory of Brain Connectome and Manipulationthe Brain Cognition and Brain Disease Institute(BCBDI)Translational Research Center for the Nervous System(TRCNS)Shenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhen-Hong Kong Institute of Brain Science-Shenzhen Fundamental Research InstitutionsShenzhenGuangdong ProvinceChina NMPA Key Laboratory for Research and Evaluation of Viral Vector Technology in Cell and Gene Therapy Medicinal Products Key Laboratory of Quality Control Technology for Virus-Based TherapeuticsGuangdong Provincial Medical Products AdministrationShenzhen Key Laboratory of Viral Vectors for BiomedicineShenzhen Institute of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina University of Chinese Academy of Sciences BeijingChina Wuhan National Laboratory for Optoelectronics Huazhong University of Science and TechnologyWuhanHubei ProvinceChina

Mapping neural circuits is critical for understanding the structure and function of the nervous *** viruses are a valuable tool for tracing neural ***,current tracers do not fully meet the needs for this approach because of various drawbacks,such as toxicity and characteristics that are difficult to ***,there is an urgent need to develop a new tracer with low toxicity and that allows for long-term *** this study,we constructed an engineered Sindbis virus(SINV)expressing enhanced green fluorescent protein(EGFP)reporter gene(SINV-EGFP)and found that it had no significant difference in biological characterization compared with the wild-type Sindbis virus in BHK-21 cells and neurons in *** injected the virus into the visual circuit of mouse brain and found that the virus infected neurons in the local injected site and anterogradely spread in the neural *** the efficiency of transmission was limited,the findings demonstrate that SINV can be used as a new anterograde tracer to map neural circuits in mouse brain and that it spreads exclusively in the anterograde ***,use of SINV in mouse brain research will provide longer time windows for circuit tracing than is possible with herpes simplex virus and vesicular stomatitis virus tracers.

关键词： anterograde lateral geniculate nucleus mouse brains neural circuit neurons retina Sindbis virus superior colliculus synapse tracer

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ReaxFF molecular dynamic simulation of primary and secondary reactions involving in sub-bituminous coal pyrolysis for tar production

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Carbon Resources Conversion 2021年第1期4卷 230-238页

作者： Yanan Qian Jin-Hui Zhan Wei Xu Zhennan Han Xiaoxing Liu Guangwen Xu State Key Laboratory of Safety and Control for Chemicals SINOPEC Research Institute of Safety Engineering Co.Ltd.Qingdao 266071China State Key Laboratory of Multiphase Complex System Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Key Laboratory on Resources Chemicals and Materials of Ministry of Education of China Shenyang University of Chemical TechnologyShenyang 110142China

ReaxFF molecular dynamic simulation combined with experimental verification was performed to understand the overall reaction mechanism,especially the primary and secondary reactions involving in tar formation of sub-bituminous coal *** relationship at atomic level is clarified between bond breakage of functional groups and products generation,revealing that the amount and order in forming each product are subject to the number of corresponding functional groups and their bond energies *** primary breakage of-C-O-and-C-C-bridge-bonds present in initial coal macromolecular generates molecular of heavy tar,whereas heavy tar can be converted into light tar through cracking side chain of aromatic rings and cyclic hydrocarbons at increased pyrolysis *** very high temperatures the cracking of short-chain hydrocarbons and residual atoms connecting to aromatic rings further occurs to generate light tar and *** remaining aromatic-ring fragments of heavy tar are likely cross-linked to form ***,the simultaneous evolution tendency of tar yield and tar quality under different pyrolysis temperatures and heating rates is obtained at molecular *** obtaining high yield and quality of tar,appropriately high temperature as well as suitable heating rate are needed to compromise the high yield of primary tar and high quality of secondarily upgraded products.

关键词： ReaxFF MD simulation Sub-bituminous coal pyrolysis Reaction paths Primary formation Secondary upgrading

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Condition Monitoring and Fault Diagnosis of Coal Mill Based on Mechanism Modeling Simulation and D-S Evidence Fusion

Condition Monitoring and Fault Diagnosis of Coal Mill Based ...

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第34届中国控制与决策会议

作者： Tian Qiu Yuchen Yang Yue Guo Xiaofeng Chen Key Laboratory of Industrial Process Measurement and Control New Technology and System North China Electric Power University School of Control and Computer Engineering North China Electric Power University North China Electric Power Research Institute Co. Ltd

The coal mill is the key equipment of powdering system in coal-fired power plants,whose working state has an important influence on the combustion stability of boiler as well as the operation ***,owing to the lack of real fault data,it is difficult and not available enough to support and achieve the research of data-driven fault diagnosis ***-type medium-speed coal mill was selected as the research object in this ***,the existing mechanism model had been further improved to make it more effective and reasonable,and we used it to respectively simulate the typical operating data of the normal condition and three fault *** paper transformed the problem of fault diagnosis into the measurement of similarity between the testing and the typical fault samples,taking the numerical distance and changing trends into account,and adopted the concept of similarity function and transformed the results into the expression and calculation of probability level,which was calculated as the diagnostic evidence of individual parameters under the same time scale.D-S evidence theory was employed to fuse the individual evidence between multiple parameters evidence,getting the fusion of multiparametric evidence as to the final diagnosis ***,the experiments verified the high accuracy of the proposed diagnostic method,and the similarity function has high rationality and feasibility.

关键词： Coal Mill system process Fault Dynamic Mathematical Model Similarity Function D-S Evidence Fusion Theory Fault Diagnosis

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