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New WHO global air quality guidelines help prevent premature deaths in China

National Science Review 2022年第4期9卷 10-12页

作者： Tao Xue Guannan Geng Xia Meng Qingyang Xiao Yixuan Zheng Jicheng Gong Jun Liu Wei Wan Qiang Zhang Haidong Kan Shiqiu Zhang Tong Zhu Institute of Reproductive and Child Health/National Health Commission Key Laboratory of Reproductive Health and Department of Epidemiology and Biostatistics School of Public HealthPeking University State Key Joint Laboratory of Environmental Simulation and Pollution Control School of EnvironmentTsinghua University School of Public Health Key Laboratory of Public Health Safety of the Ministry of Educationand Key Laboratory of Health Technology Assessment of the Ministry of HealthFudan University Center of Air Quality Simulation and System Analysis Chinese Academy of Environmental Planning College of Environmental Sciences and Engineering Peking University School of Energy and Environmental Engineering University of Science and Technology Beijing Clean Air Asia Ministry of Education Key Laboratory for Earth System Modeling Department of Earth System ScienceTsinghua University

The air quality guidelines （AQGs） issued by the World Health Organization （WHO） in 2005 are key references for the National Ambient Air Quality Standards （NAAQSs） in *** 22September 2021,the WHO issued new AQGs （NAQGs）[1],which propose more stringent targets to control exposure to multiple air pollutants,including fine particulate matter (PM2.5) and ozone （O3）,to which,in 2019,451 million premature deaths,globally,were attributable [2].

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Reliability Design of Manipulator Joint for China Space Station 2

Reliability Design of Manipulator Joint for China Space Stat...

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2nd International Conference on Artificial Intelligence, Automation, and High-Performance Computing, AIAHPC 2022

作者： Li, Delun Zhu, Chao Zhang, Yun Bai, Mei Huang, Zhipeng Xie, Zongwu Liu, Teng Fu, Hao State Key Laboratory of Robotics and System Harbin Institute of Technology Harbin150001 China Beijing Key Laboratory of Intelligent Space Robotic Systems Technology and Applications Beijing Institute of Spacecraft System Engineering CAST Beijing100094 China Beijing Satellite Manufacturing Co. Ltd. Beijing100094 China Beijing Institute of Space Environment Engineering Beijing100094 China

ISBN: (纸本)9781510657717

The TianHe manipulator is responsible for major tasks such as China Space Station construction, operation, and supporting astronaut's extravehicular operations. The joint is the direct execution part of the manipulator to realize flexible movement, and it is the key component to ensure the core functions and performance of the China Space Station manipulator, The composition of the joint is complex, and the experience of its reliability design is very poor. So the research of reliability design method for the joint is of great significance. Starting from the joint reliability design method, this paper uses various methods such as redundant design, margin design, and environmental adaptability design to complete the joint reliability design comprehensively. The ideas and methods for reliability design for the joint of the China Space Station manipulator introduced in this paper have important reference value for the reliability design for the space complicated electromechanical products. © 2022 SPIE. All rights reserved.

关键词： Space stations

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Design of a Flexible Capture Mechanism Inspired by Sea Anemone for Non-cooperative Targets

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Chinese Journal of Mechanical Engineering 2021年第4期34卷 236-248页

作者： Jiankun Yang Chengwei Ren Chenghao Yang Youyu Wang Shumin Wan Rongjie Kang Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin UniversityTianjin 300350China State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110169China Beijing Institute of Spacecraft System Engineering CAST Beijing 100094China

Robotic grippers have been used in industry as end-effectors but are usually limited to operations in pre-defined ***,few devices can capture irregularly shaped dynamic targets in space,underwater and other unstructured *** this paper,a novel continuum arm group mechanism inspired by the morphology and motions of sea anemones is *** is able to dissipate and absorb the kinetic energy of a fast moving target in omni-direction and utilize multiple arms to wrap and lock the target without accurate positioning ***-driven actuation systems are implemented in the individual continuum arms,achieving both bending motion and stiffness *** finite element method,the influence of different configurations of the continuum arm group on the capture performance is analyzed.A robotic prototype is constructed and tested,showing the presented arm group mechanism has high adaptability to capture targets with different sizes,shapes,and incident angles.

关键词： Non-cooperative targets Continuum arm group Wire-driven mechanism

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Terahertz Channel Modeling for Integrated Sensing and Communication 24

Terahertz Channel Modeling for Integrated Sensing and Commun...

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24th IEEE International Workshop on Signal Processing Advances in Wireless Communications, SPAWC 2023

作者： Han, Jiayue He, Danping Pan, Ran Guan, Ke Dou, Jianwu Zhong, Zhangdui State Key Laboratory of Advanced Rail Autonomous Operation Beijing100044 China Beijing Engineering Research Center of High-speed Railway System Beijing100044 China Frontiers Science Center for Smart High-Speed Railway System Beijing100044 China Zte Corporation State Key Laboratory of Mobile Network and Mobile Multimedia Technology Shenzhen518055 China

ISBN: (纸本)9781665496261

To realize the vision of 'intelligent connection of all things and digital twin', the terahertz (THz) technology becomes a key candidate technology for the sixth generation mobile communication. Since the THz band has large bandwidth, high-frequency band, and larger antenna arrays, it is possible to achieve integrated sensing and communication (ISAC). The research on THz and ISAC technologies including channel modeling is still in the attack stage. This paper proposes a scattering-based THz channel modeling approach for ISAC with the addition of a meteorological attenuation. Once the reference points (RPs) have been determined, the scattering clusters for communication and sensing are subsequently determined. The ray-tracing (RT) simulation is used to provide a reference for the determination of the RPs. To achieve traversal RT simulations, it is recommended to use the 'sphere coordinate system positioning method' to place the receivers. The channel parameters extracted by the proposed THz channel model are compared with the QuaDriGa model to verify its feasibility in the wireless backhaul scenario. The evaluation results show that the channel model can characterize both communication and sensing channels, hopefully contributing to THz and ISAC channel modeling. © 2023 IEEE.

关键词： Antenna arrays

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Raman spectrum feature extraction and diagnosis of oil-paper insulation ageing based on kernel principal component analysis

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High Voltage 2021年第1期6卷 51-60页

作者： Dingkun Yang Chen Weigen Shi Haiyang Wan Fu Zhou Yongkuo State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityShapingba DistrictChongqingChina

Raman spectroscopy, with its specific ability to generate a unique fingerprint‐like spec-trum of certain substances, has attracted much attention in diagnosing the ageing degree of oil-paper insulation. In this study, the feature extraction and ageing diagnosis methods of oil-paper insulation Raman spectroscopy data are further studied. Based on the non‐linear analysis of Raman spectra of different ageing samples, kernel principal component analysis was applied to extract the spectral features, and the back‐propagation neural network was used to build a diagnosis model with high diagnostic accuracy. The results show that Raman spectroscopy combined with kernel principal component analysis and the back‐propagation neural network can diagnose the ageing state of oil-paper insu-lation, with a diagnostic accuracy of 91.43% (64/70). The proposed method provides an effective and feasible method for the ageing assessment of oil‐immersed electrical equipment.

关键词： insulation analysis component

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MMC-DC/DC Converter and Its Control Strategy for Offshore Full DC Wind Power system 6

MMC-DC/DC Converter and Its Control Strategy for Offshore Fu...

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6th International Conference on Power and Energy Applications, ICPEA 2023

作者： Xu, Qianqian Zhou, Yanbing Liu, Qihui Tian, Xin Yuan, Zhenhua North China Electric Power University State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources Beijing China State Grid Shandong Economic Technology Research Institute Jinan China

ISBN: (纸本)9798350359053

The development trend for large-scale offshore wind farms in the future is offshore wind farms with complete DC, which can enhance wind power collecting and delivery efficiency and conserve resources on offshore platforms. It is also more appropriate for long-distance, high-capacity wind energy transmission. When building offshore full DC wind farms, one of the essential and fundamental pieces of equipment is the highvoltage, high-power delivery DC/DC converter. The research object in this paper is the modular multilevel high-voltage DC/DC converter. Two modular multilevel converters (MMC) are connected face-to-face, and control, voltage equalization, and modulation strategies are created. The MMC-DC/DC converter can be utilized on the output side of fully DC offshore wind farms and offers the benefits of flexible control and a high voltage carrying capability. Finally, to confirm the efficacy of the chosen topology and the entire control method, a simulation model is constructed using the Matlab/Simulink program. © 2023 IEEE.

关键词： DC-DC converters

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A New Indoor Unmanned Vehicle Navigation system Based on The Combination of Lidar and IMU 20

A New Indoor Unmanned Vehicle Navigation System Based on The...

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20th IEEE International Conference on Mechatronics and Automation, ICMA 2023

作者： Zhu, Ruihui Yu, Baoguo The 54th Research Institute of China Electronics Technology Group Corporation State Key Laboratory of Satellite Navigation System and Equipment Technology 589 ZhongShan Street Qiaoxi District Shijiazhuang050081 China

ISBN: (纸本)9798350320831

Under the condition of indoor denial, the indoor navigation of unmanned ground vehicles is facing great challenges. In order to solve this problem, we introduce a loose integrated navigation system based on lidar and inertial measurement unit (IMU), and propose a new hybrid scanning matching algorithm based on lidar to estimate the relative position and direction change of vehicles. The algorithm combines traversal search and mathematical optimization algorithm. Firstly, the fitness function is introduced into the traversal search algorithm to find the optimal estimated value of vehicle attitude, and then the estimated value is used as the initial value of the numerical optimization algorithm for further optimization. Finally, the lidar estimated attitude is loosely combined with the results of DRS prediction through unscented Kalman filter (UKF), so as to reduce the cumulative error of inertial sensor. The actual experiment is carried out on the self-developed unmanned ground vehicle platform. The results show that the indoor unmanned vehicle navigation system proposed in this paper can effectively reduce the error accumulation of DRS, and the positioning error is reduced by 92.4% compared with hectorslam method. © 2023 IEEE.

关键词： Optical radar

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Comparative Analysis of Aggregation Topologies for All-DC Offshore Wind Farms 10

Comparative Analysis of Aggregation Topologies for All-DC Of...

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10th International Conference on Power and Energy systems Engineering, CPESE 2023

作者： Liu, Yixin Zhou, Yanbing Liu, Qihui Tian, Xin Yuan, Zhenhua North China Electric Power University State Key Laboratory of Alternate Electrical Power System with Renewable Energy Sources Beijing China State Grid Shandong Economic & Technology Research Institute Jinan China

ISBN: (纸本)9798350327625

Full DC offshore wind farms are the future development trend, but due to a lack of practical engineering experience, it is necessary to develop an economic analysis model of DC aggregating topology, along with a reliable large-capacity wind farm example and a comparison of various aggregating topologies. In order to improve the reliability calculation method and account for the effects of faults at various locations on the full wind farm, this paper establishes an economic analysis model from three perspectives of economy, power loss, and reliability. It also performs a quantitative comparative analysis of the calculation examples. The analysis's findings indicate that the parallel-type wind farm has higher reliability, but the series-parallel wind farm has clear advantages in terms of cost and power loss, and it is fiercely competitive when choosing the future all-DC offshore wind farm aggregation topology. © 2023 IEEE.

关键词： Economic analysis

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Influence of thermal ageing on high-field polarisation characteristics and conductivity behaviour of submarine polymeric cables insulation

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High Voltage 2023年第1期8卷 138-148页

作者： Xize Dai Jian Hao Gian Carlo Montanari Zheng Jian Ruijin Liao Xinlong Zheng State Key Laboratory of Power Transmission Equipment&System Security and New Technology Chongqing UniversityChongqingChina Department of Energy Aalborg UniversityAalborgDenmark Center for Advanced Power Systems Florida State UniversityTallahasseeFloridaUSA Shinan Power Supply Branch Company of State Grid Chongqing Electric Power Company NananChina Zhoushan Power Supply Branch Company of State Grid Zhejiang Electric Power Company ZhoushanChina

Diagnosing insulation intrinsic ageing is essential for preventing insulation failure of submarine cables,and in case of failure,helping in any decision about maintenance *** this study,a novel aged cable diagnosis approach based on high-voltage frequency domain spectroscopy(HV-FDS)with broader frequency width is proposed to analyse the high-field polarisation characteristics and conductivity behaviour of 500 kV submarine polymeric cables insulation,aiming to support the evaluation of overall insulation *** measurement principle of HV-FDS and relaxation mechanism are stated,and then focus is on studying the extent of change of polarisation and conduction properties of submarine cables insulation as a function of ageing stress and ***,the high-field polarisation characteristics and conductivity behaviour are discussed in-depth based on the carrier transport and trap ***,the novel diagnostic indicator based on the high-field characteristics is extracted to quantify the thermal ageing state of submarine cables *** show that the high-field polarisation characteristics and conductivity behaviour seem to become sensitive diagnostic quantities if measured at reasonably high voltage,which are able to reveal mechanisms associated with thermo-oxidative ageing as that generated in the testing procedure considered in this *** is considerably higher than that experienced in typical dielectric spectroscopy approaches.

关键词： behaviour insulation characteristics

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Parameter Optimization and SSR Mitigation of DFIG Considering PLL

Parameter Optimization and SSR Mitigation of DFIG Considerin...

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2022 Power system and Green Energy Conference, PSGEC 2022

作者： Zhang, Fan Yuan, Hao Zhou, Baorong Zhang, Qian Jin, Xuyang State Key Laboratory of Hvdc Electric Power Research Institute Csg Guangzhou China Chongqing University State Key Laboratory of Power Transmission Equipment and System Security and New Technology Chongqing China

ISBN: (数字)9781665499934

ISBN: (纸本)9781665499934

The phase-locked loop(PLL) is one of the important factors causing sub-synchronous resonance(SSR). The existing research on the mechanism analysis and mitigation measures of SSR do not fully consider its influence. This paper proposes a parameter optimization design strategy for DFIG combining orthogonal experiment method and particle swarm optimization. Firstly, a model of DFIG connected to weak grid by series compensation considering PLL is built. Then, the proportional and integral coefficients of the grid-side controller, rotor-side controller, and PLL are chosen as experiment factors. The SSR and dynamic characteristics of the grid-connected system are considered comprehensively by the compound weighting method. It reveals the sensitivity and influence trend of parameters on the system performance. Finally, the simulation results demonstrate that compared with the traditional orthogonal method, the proposed strategy can mitigate SSR more effectively while ensuring stronger anti-interference. © 2022 IEEE.

关键词： Phase locked loops

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