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Mercury transformation processes in nature: Critical knowledge gaps and perspectives for moving forward

Journal of Environmental Sciences 2022年第9期34卷 152-165页

作者： Zhiyuan Gao Wang Zheng Yanbin Li Yurong Liu Mengjie Wu Shouying Li Ping Li Guangliang Liu Xuewu Fu Shuxiao Wang Feiyue Wang Yong Cai Xinbin Feng Baohua Gu Huan Zhong Yongguang Yin Centre for Earth Observation Science and Department of Environment and GeographyUniversity of ManitobaWinnipegMB R3T 2N2Canada Institute of Surface-Earth System Science Tianjin UniversityTianjin 300192China Key Laboratory of Marine Chemistry Theory and Technology Ministry of Education and College of Chemistry and Chemical EngineeringOcean University of ChinaQingdao 266100China State Key Laboratory of Agricultural Microbiology Huazhong Agricultural UniversityWuhan 430070China School of the Environment Nanjing UniversityState Key Laboratory of Pollution Control and Resource ReuseNanjing 210023China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Department of Chemistry and Biochemistry Florida International UniversityMiamiFL 33199USA School of Environment and State Key Joint Laboratory of Environment Simulation and Pollution Control Tsinghua UniversityBeijing 100084China Environmental Sciences Division Oak Ridge National LaboratoryOak RidgeTennessee 37831USA Environmental and Life Sciences Program(EnLS) Trent UniversityPeterboroughOntario K9L 0G2Canada Research Center for Eco-Environmental Sciences Chinese Academy of SciencesBeijing 100085China

The transformation of mercury(Hg) in the environment plays a vital role in the cycling of Hg and its risk to the ecosystem and human health. Of particular importance are Hg oxidation/reduction and methylation/demethylation processes driven or mediated by the dynamics of light, microorganisms, and organic carbon, among others. Advances in understanding those Hg transformation processes determine our capacity of projecting and mitigating Hg risk. Here, we provide a critical analysis of major knowledge gaps in our understanding of Hg transformation in nature, with perspectives on approaches moving forward. Our analysis focuses on Hg transformation processes in the environment, as well as emerging methodology in exploring these processes. Future avenues for improving the understanding of Hg transformation processes to protect ecosystem and human health are also explored.

关键词： Mercury oxidation reduction methylation demethylation isotope fractionation

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Real-time Implementation and Evaluation of SDR-based Deep Joint Source-Channel Coding

Real-time Implementation and Evaluation of SDR-based Deep Jo...

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IEEE Conference on Vehicular Technology (VTC)

作者： Maolin Liu Wei Chen Jialong Xu Bo Ai State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University China Frontiers Science Center for Smart High-speed Railway System Key Laboratory of Railway Industry of Broadband Mobile Information Communications Beijing Engineering Research Center of High-speed Railway Broadband Mobile Communications School of Information Engineering Zhengzhou University Zhengzhou China

ISBN: (纸本)9781665454698

Benefiting from the advantage of joint source-channel coding in the finite block length regime and the advancement of AI technologies, deep joint source channel coding (DJSCC) has been extensively investigated for various sources (e.g., text source, image source, and video source) and achieved remarkable performance in limited bandwidth and low signal-to-noise ratios (SNRs). However, the performance gain brought by DJSCC methods is all observed via simulations in literature, where synchronization, channel estimation and the power amplifier are assumed to be perfect. In this paper, we design a software-defined radio (SDR) based platform to validate the DJSCC method for image transmission in real wireless scenarios.

关键词： Wireless communication Vehicular and wireless technologies Power amplifiers Peak to average power ratio Performance gain Software Real-time systems

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Terahertz Enabled Use Cases for Smart Mobility towards B5G and 6G Communications

Terahertz Enabled Use Cases for Smart Mobility towards B5G a...

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European Conference on Antennas and Propagation, EuCAP

作者： Kun Yang Haofan Yi Ke Guan Yang Shen Danping He Bo Ai Zhangdui Zhong Guangdong Communications and Networks Institute Guangzhou China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing China Beijing Engineering Research Center of High-speed Railway Broadband Mobile Communications Beijing China Frontiers Science Center for Smart High-speed Railway System Beijing China

The emerging technology terahertz (THz) communication is envisioned to provide high-data-rate links. For the design of THz communication system, an accurate channel model is unavoidable. As a typical representative of deterministic models, ray-tracing (RT) method based on optical theory is relevant to the physical properties of THz waves. In this study, with the consideration of real-world use, two cases are made for vehicle-to-infrastructure (V2I) and drone communications. These two cases represent two ends of THz mobile communications from terrestrial to aerial one. The V2I channel is analyzed with the aid of RT. The Doppler effect caused by moving vehicles will be a great challenge for the system design. As for the drone communications, the channel model should consider three-dimensional characteristics, including scenario, velocity, trajectory, antenna pattern, etc. The provided brief survey on the two most relevant scenarios for smart mobility will be foundation for the THz channel modeling.

关键词： Doppler shift Solid modeling Three-dimensional displays Vehicle-to-infrastructure Simulation Trajectory Channel models

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QoS-aware User Association and Transmission Scheduling for Millimeter-Wave Train-ground Communications

arXiv

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arXiv 2023年

作者： Zhang, Xiangfei Niu, Yong Yang, Tao Xiao, Xian Ding, Jianwen Chen, Sheng Zhong, Zhangdui Wang, Ning Ai, Bo State Key Laboratory of Rail Traffic Control and Safety China Frontiers Science Center for Smart High-speed Railway System Beijing Jiaotong University Beijing100044 China State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing100044 China National Mobile Communications Research Laboratory Southeast University Nanjing211189 China School of Electronics and Computer Science University of Southampton SouthamptonSO17 1BJ United Kingdom Beijing Engineering Research Center of High-speed Railway Broadband Mobile Communications Beijing Jiaotong University Beijing100044 China School of Information Engineering Zhengzhou University Zhengzhou450001 China

With the development of wireless communication, people have put forward higher requirements for train-ground communications in the high-speed railway (HSR) scenarios. With the help of mobile relays (MRs) installed on the roof of the train, the application of Millimeter-Wave (mm-wave) communication which has rich spectrum resources to the train-ground communication system can realize high data rate, so as to meet users’ increasing demand for broad-band multimedia access. Also, full-duplex (FD) technology can theoretically double the spectral efficiency. In this paper, we formulate the user association and transmission scheduling problem in the mm-wave train-ground communication system with MR operating in the FD mode as a nonlinear programming problem. In order to maximize the system throughput and the number of users meeting quality of service (QoS) requirements, we propose an algorithm based on coalition game to solve the challenging NP-hard problem, and also prove the convergence and Nash-stable structure of the proposed algorithm. Extensive simulation results demonstrate that the proposed coalition game based algorithm can effectively improve the system throughput and meet the QoS requirements of as many users as possible, so that the communication system has a certain QoS awareness. Copyright © 2023, The Authors. All rights reserved.

关键词： Game theory

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Measurement and ray-tracing simulation for millimeter-wave automotive radar 4

Measurement and ray-tracing simulation for millimeter-wave a...

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4th IEEE International Conference on Electronic Information and Communication Technology, ICEICT 2021

作者： Zhu, Luoyan He, Danping Ai, Bo Zhong, Zhangdui Zhu, Fusheng Wang, Zhigang State Key Laboratory of Rail Traffic Control and Safety Beijing Jiaotong University Beijing100044 China Engineering Research Center of High-speed Railway Broadband Mobile Communications Beijing100044 China Frontiers Science Center for Smart High-speed Railway System Beijing100044 China Key Laboratory of Railway Industry of Broadband Mobile Information Communications Beijing100044 China Guangdong Communications and Networks Institute

ISBN: (纸本)9781665432030

The underlying requirement of autonomous driving test orienting the future Internet of Intelligent Vehicles (IoIV) needs knowledge of authentic millimeter-wave (mmWave) radar simulation system. In this paper, a mmWave radar measurement system, which is validated by two corner reflectors with a constant radar cross-sectional (RCS), is set up to carry out the parallel parking measurement campaign on road. The key characteristics of the measurement, including Range-Power profile, Range-Doppler spectrum, and Range-Angle spectrum are obtained and analyzed for the subsequent ray tracing (RT) simulation. The RCSs of key targets are estimated based on the measurement results and provide a visible cue for calibrating EM parameters, which are then matched with the measured ones. The calibrated simulation results are then compared with the measurement results, which realizes the closed-loop verification and analysis. © 2021 IEEE

关键词： Radar measurement

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Coordination and Optimization of Multi-controller Parameters in Power system Based on a Sphere Artificial Immune Algorithm

Coordination and Optimization of Multi-controller Parameters...

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第40届中国控制会议

作者： Yu Miao Du Weijie Li Jinglin School of Mechanical-electronic and Automobile Engineering Beijing University of Civil Engineering and Architecture Beijing Engineering Research Center of Monitoring for Construction Safety State Key Laboratory of Control and Simulation of Power System and Generation Equipment Tsinghua University

Interconnected power system is becoming more and more complex, in order to improve the performance of power system, the number and type of controllers are increasing. The interaction among controllers may be detrimental to the performance of power system, which would weak the performance of controllers. The purpose of this paper is to solve the problem of coordination control among controllers, firstly, a multi-controller parameter coordination model is given. Then, a spherical artificial immune algorithm is proposed to coordinate and optimize parameters among multi-damping controllers. This algorithm can reduce the computational complexity and optimize parameters globally. Finally, this algorithm is verified by the simulation of the four-machine two-area system. Compared with one similar method, simulation results show that this algorithm can effectively realize the coordination control among multi-damping controllers.

关键词： Sphere artificial immune system power system coordination control parameter optimization

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Land water availability altered by historical land use and land cover change

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npj Climate and Atmospheric Science 2025年第1期8卷 1-10页

作者： Tao Tang Junji Cao Jun Ge Haiyun Shi Science Center for Earth System Numerical Simulation Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China State Key Laboratory of Earth System Numerical Modelling and Application Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China Joint International Research Laboratory of Atmospheric and Earth System Sciences School of Atmospheric Sciences Nanjing University Nanjing China School of Environmental Science and Engineering Southern University of Science and Technology Shenzhen China

Anthropogenic land use and land cover changes (LULCC) have profound impacts on land water availability, defined as precipitation (P) minus evapotranspiration (ET), through biophysical pathways. However, such impacts have long been debated mostly due to either the inadequate consideration of the atmospheric feedbacks arising from the changes in circulations and background climate in observation-based studies or unrealistic representation of historical LULCC in idealized-simulation-based studies. To overcome these limitations, we use the latest simulations from multiple Earth system models to investigate the impacts of historical (1850–2014) and future (2015–2100) LULCC on P–ET. Here we show that historical LULCC caused an insignificant reduction in global P–ET, mainly in wet regions. Locally, P–ET tends to decrease (increase) in deforestation (reforestation) regions mainly due to the dominant role of precipitation. Approximately 3.8% of the global land area (5.1 Mkm2) even has experienced opposite regime shifts, in which negative (positive) P–ET becomes positive (negative). Under a medium-to-high warming scenario, however, reforestation is projected to decrease P–ET even over reforested areas. This study not only elucidates the hydrological effects of realistic LULCC with atmospheric feedbacks being fully considered, but also highlights that the relative importance of the local effects and atmospheric feedbacks varies with background climate changes. We stress that background climate changes and feedbacks due to LULCC should be considered when planning reforestation and other land-use policies.

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research on Highly Anti-Humidity and Selective NO2 Detection Based on GaN/MoO3 N-N Heterojunction

SSRN

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SSRN 2024年

作者： Hong, Yutao Han, Dan Li, Donghui He, Xiuli Zhao, Li Wang, Weidong Li, Hongwei Sang, Shengbo Liang, Hua Shanxi Key Laboratory of Micro Nano Sensors & Artificial Intelligence Perception College of Electronic Information and Optical Engineering Taiyuan University of Technology Taiyuan030024 China Key Lab of Advanced Transducers and Intelligent Control System Ministry of Education Taiyuan University of Technology Taiyuan030024 China State Key Laboratory of Transducer Technology Aerospace Information Research Institute Chinese Academy of Sciences Beijing100190 China Bioengineering Research Center Medical Innovation Research Division Chinese PLA General Hospital Beijing China Shanxi Academy of Medical Sciences China

Effective and accuratedetection of NO2 gas is crucial for protecting the environment and public health. In this work, balsam pear-like GaN/MoO3 porous nanosheets (GaN/MoO3) composites were synthesized by the in situ assembling, the hydrothermal method, and the nitridation process to detect NO2. A series of characterization methods were used to manifest the successful synthesis and to analyze the morphology and elemental composition features of GaN/MoO3 composites. The results of the gas-sensing experiments show that at the operating temperature of 225 °C, the gas sensor based on the optimal ratio of GaN/MoO3 composites exhibits a low theoretical limit of detection (0.78 ppb) for NO2, which is significantly improved compared with the limit of detection of MoO3 (5 ppm). Further, the response value of the sensor based on GaN/MoO3 composites to 200 ppm NO2 (44.74) is 4.36 times higher than that of the sensor based on pure GaN, with an improvement in stability. Meanwhile, the sensor also possessed excellent repeatability, selectivity, stability, and splendid anti-humidity ability at 15-70 % RH. The improved gas-sensing performance is ascribed to the unique microstructure of both GaN and MoO3, and the heterojunction effect between them. This work provides a way to improve the efficiency and anti-humidity ability of real-time monitoring of NO2 for the sensors of MoO3-based composite. © 2024, The Authors. All rights reserved.

关键词： Gallium nitride

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MRI-guided robot intervention—current state-of-the-art and new challenges

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Med-X 2023年第1期1卷 141-181页

作者： Shaoping Huang Chuqian Lou Ying Zhou Zhao He Xuejun Jin Yuan Feng Anzhu Gao Guang-Zhong Yang Institute of Medical Robotics and School of Biomedical Engineering Shanghai Jiao Tong UniversityShanghai 200240China National Engineering Research Center of Advanced Magnetic Resonance Technologies for Diagnosis and Therapy(NERC-AMRT) Shanghai Jiao Tong UniversityShanghai 200240China Materials and Technology Center of Robotics EmpaDübendorf 8600Switzerland State Key Lab of Metal Matrix Composites and School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China Institute of Medical Robotics and Department of Automation Shanghai Jiao Tong UniversityShanghai 200240China The Key Laboratory of System Control and Information Processing Ministry of EducationShanghai 200240China

Magnetic Resonance Imaging(MRI)is now a widely used modality for providing multimodal,high-quality soft tissue contrast images with good spatiotemporal resolution but without subjecting patients to ionizing *** addition to its diagnostic potential,its future theranostic value lies in its ability to provide MRI-guided robot intervention with combined structural and functional mapping,as well as integrated instrument localization,target recognition,and in situ,in vivo monitoring of the therapeutic *** of current applications include neurosurgery,breast biopsy,cardiovascular intervention,prostate biopsy and *** applications in targeted drug delivery and MRI-guided chemoembolization are also being *** promising progress has been made in recent years,there are still significant basic science research and engineering *** paper provides a comprehensive review of the current state-of-the-art in MRI-guided robot intervention and allied technologies in actuation,sensing,new materials,interventional instruments,and interactive/real-time *** future research directions and new clinical developments are also discussed.

关键词： MRI-guided robot intervention Actuation Sensing Materials Interventional instruments Interactive/realtime MRI

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Accurate Resilient Average Consensus via Detection and Compensation

Accurate Resilient Average Consensus via Detection and Compe...

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IEEE Conference on Decision and control

作者： Wenzhe Zheng Zhiyu He Jianping He Chengcheng Zhao Shanghai Jiao Tong University the Key Laboratory of System Control and Information Processing Ministry of Education of China and Shanghai Engineering Research Center of Intelligent Control and Management Shanghai China State Key Laboratory of Industrial Control Technology Zhejiang University Hangzhou China

ISBN: (纸本)9781665436601

We study the problem of resilient average consensus for multi-agent systems with misbehaving nodes. Different from the widely investigated Mean-Subsequence-Reduced-based and detection-isolation-based approaches which guarantee consensus, in this paper, we address this problem by detecting misbehaviors, mitigating corresponding impact and achieving accurate average consensus. General types of misbehaviors are considered, including deception attacks and accidental faults. We characterize the disturbances of misbehaving nodes in a distributed manner via two-hop communication information and develop a deterministic detection-compensation-based consensus (D-DCC) algorithm with a decaying fault-tolerant error bound. Considering scenarios where such information is intermittently available, a stochastic extension named S-DCC is proposed. We prove that D-DCC and S-DCC allow nodes to asymptotically achieve average consensus exactly and in expectation, respectively. Finally, extensive simulations verify the effectiveness of the proposed algorithms.

关键词： Fault tolerance Adaptation models Conferences Fault tolerant systems Multi-robot systems Multi-agent systems Convergence

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