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Hydrochemistry characteristics and genesis of shallow groundwater in diverse industrial agglomeration areas in typical alluvial plain of the Yellow River

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Science of the Total Environment 2025年 958卷 177764页

作者： Zhang, Fan Yuan, Ying Xi, Beidou Lu, Haojie Jiang, Yu Hui, Kunlong Tan, Wenbing Wang, Hui Meng, Fanhua State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences Beijing100012 China State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution Chinese Research Academy of Environmental Sciences Beijing100012 China

The groundwater environment in the middle and upper reaches of the Yellow River in China has attracted extensive attention. But, the hydrochemistry characteristics and genesis of shallow groundwater in diverse industrial agglomeration areas in typical alluvial plain of the Yellow River are still unknown. In this study, geochemical analysis methods, the positive matrix factorisation model, and the geodetector model were used to multidimensional analyze. The results showed that 78 % of the groundwater samples had high-alkalinity-risk and high-salinity-risk, and the water quality was poor and unsuitable for irrigation. "Very poor" and "undrinkable" samples accounted for 26.31 %. The weathering of calcium magnesium minerals and the dissolution of soluble sulfate were important sources of the main chemical components of the groundwater. However, evaporation and concentration gradually dominated from the inclined plain of the piedmont to the alluvial plain of the Yellow River. Domestic and agricultural activities were important sources of nitrogen species (NO3−, NO2−, and NH4+). The presence of Al, Mn, Zn, and Pb was caused by the production activities of various enterprises. The pollution contributors of natural sources, domestic and agricultural activities, industrial production and other sources were 29.49 %, 17.05 %, 31.41 %, and 22.05 %, respectively. Groundwater velocity and enterprise type were the main factors driving groundwater pollution by these four metal substances. The interaction between enterprise type and groundwater velocity had the greatest influence on the concentrations of Al, Mn, and Zn. Moreover, the interaction between enterprise type and the distance from enterprise had the greatest influence on Pb levels. Overall, groundwater pollution in the study area was the result of both natural and human factors. The findings of this study can offer valuable insights and theoretical support for preventing groundwater pollution in other industrial agglomerat

关键词： Groundwater geochemistry

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Multi-objective crashworthiness optimization of novel functionally-graded variable section double-hexagonal crash box

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Zhendong yu Chongji/Journal of Vibration and Shock 2025年第11期44卷 50-60and69页

作者： Xiong, Feng Zeng, Shupeng Wang, Zhanfei Zhang, Shuai Wang, Dengfeng Xu, Hongyu Joint International Research Laboratory of Intelligent Manufacturing & Control of Key Parts for Energy-efficient & New Energy Vehicles Ministry of Education Chongqing University of Technology Chongqing400054 China State Key Laboratory of Intelligent Green Vehicle and Mobility Tsinghua University Beijing100084 China School of Vehicle and Traffic Engineering Henan University of Science and Technology Luoyang471000 China State Key Laboratory of Automotive Simulation and Control Jilin University Changchun130012 China

In order to synergistically improve the crashworthiness safety and lightweight level of the oar body, a novel functionally-graded variable section double-hexagonal crash box was designed and proposed. The substructure at its lower end with regulär shape, namely functionally-graded variable section double-hexagonal tube (FS-DHT), was extracted as research subject, on which parametric geometric modeling was conducted. The finite element model of FS-DHT under axial crushing was established and verified by experiments. A comparative study concerning crashworthiness and energy absorption characteristics under axial crushing was conducted among FS-DHT, traditional straight DHT (S-DHT) and conical DHT (C-DHT). The influence of the tube wall thickness, the circumcircle radius differences at upper and lower end face of inner and outer hexagonal tubes, and the gradient exponent on the crashworthiness and energy absorption characteristics of FS-DHT under axial crushing was explored. A multi-objective optimization was carried out on FS-DHT by combining the optimal Latin hypercube sampling, response surface Surrogate model and the second-generation non-dominating sorting genetic algorithm, then verified. The finite element model of " bumper-crash box" assembly under axial crushingwas further established to verify the improvement effect of FS-DHT optimization on the crashworthiness of functionally-graded variable section double-hexagonal crash box. The results show that after optimization of FS-DHT, its specific energy absorption (SEA) increases by 21. 61% while its initial peak crushing force (IPCF) decreases by 13.40%, which meanwhile promotes the energy absorption (EA) of functionally-graded variable section double-hexagonal crash box to increase by 17. 14% and the corresponding IPCF at the bumper to decrease by 6. 46%, indicating a good multi-objective collaborative crashworthiness optimization is obtained. An effective novel structure and new approach are provided for synerg

关键词： Multiobjective optimization

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Embedded plastics and carbon emissions:future trends and challenges ahead

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Science Bulletin 2025年第7期70卷 997-1000页

作者： Shang Zhang Jinhui Li Guochang Xu Quanyin Tan State Key Joint Laboratory of Environment Simulation and Pollution Control School of EnvironmentTsinghua UniversityBeijing 100084China Material Cycles Division National Institute for Environmental StudiesTsukuba305-8506Japan

In the past five decades,global plastic production has increased at an average yearly growth rate of 8.4%,which is significantly higher than that of other basic materials such as cement,steel,and aluminum[1,2].Moreover,the amount of global plastic waste more than doubled between 2000 and 2019,reaching an annual production of 353 million tons(Mt)[3].It was further estimated that plastic accounted for approximately 12%of municipal waste in 2016 globally[4].

关键词： global production waste municipal waste plastics carbon emissions growth rate

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Cost-Effective Mapping of Hyperlocal Air Pollution Using Large-Scale Mobile Monitoring and Land-Use Machine Learning

ACS ES&T Air

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ACS ES&T Air 2025年第2期2卷 151-161页

作者： Tie Zheng Yifan Wen Sheng Xiang Pan Yang Xuan Zheng Yan You Shaojun Zhang Ye Wu School of Environment State Key Joint Laboratory of Environment Simulation and Pollution Control Tsinghua University Beijing 100084 China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Beijing Normal University Beijing 100875 China State Key Laboratory of Pollution Control and Resource Reuse Tongji University Shanghai 200092 China；College of Environmental Science and Engineering Tongji University Shanghai 200092 China College of Chemistry and Environmental Engineering Shenzhen University Shenzhen 518060 China Macao Environmental Research Institute Macau University of Science and Technology Macau 999078 China；National Observation and Research Station of Coastal Ecological Environments in Macao Macao Environmental Research Institute Macau University of Science and Technology Macao 999078 China School of Environment State Key Joint Laboratory of Environment Simulation and Pollution Control Tsinghua University Beijing 100084 China；State Environmental Protection Key Laboratory of Sources and Control of Air Pollution Complex Beijing 100084 China；Beijing Laboratory of Environmental Frontier Technologies Beijing 100084 China

The advent of large-scale mobile monitoring using fast-response instruments has enabled hyperlocal mapping (≤100 m) of traffic-related air pollution (TRAP), with important implications for air quality management. However, most related studies have been confined within small areas due to the high cost and labor intensity. This study pioneers a cost-effective TRAP mapping method by incorporating large-scale mobile monitoring and land-use machine learning (LUML). Here, over 4.6 million 1 Hz high-frequency measurements (∼1300 h) were collected on a part of major roadways in the Chinese megacity of Shenzhen. Unmeasured locations were estimated by LUML models to reduce measurement costs and labor intensity. Various ML algorithms and varying spatial aggregation segment lengths were incorporated to optimize the model performance. Hyperlocal maps of NO, NO2, and PM2.5were predicted across the entire road network covering over 1700 km2. Based on our results, LU-RF (random forest) for mapping NO and NO2and LU-GBM (Gradient Boosting Machine) for mapping PM2.5, demonstrated superior performance. Deep learning models, in contrast, did not yield comparable results. Finer partitioning of road segments (≤100 m) improved NO prediction performance, but worsened that for NO2and PM2.5. By deployment of optimal ML algorithms and segment lengths, the TRAP mapping accuracy increased by 20–80% compared to conventional land-use regression models. This study provides a promising and cost-effective approach to hyperlocal air pollution mapping and management in cities worldwide.

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Master-Slave Game Strategy for Electric Heating Load Group Considering Differences of Heterogeneous Household Types and Aggregation Structure

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Dianli Xitong Zidonghua/Automation of Electric Power Systems 2025年第10期49卷 58-66页

作者： Yang, Mao Wang, Jinxin Fang, Guozhong Zhu, Yidan Wang, Yuxin Su, Xin Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin132012 China Northeast Branch of State Grid Corporation of China Shenyang110179 China

The regulation capability of the new power system dominated by renewable energy at the source side is gradually deteriorating. Exploiting the load-side regulation potential to participate in demand response has become an important approach to enhance grid regulation capacity. Firstly, taking distributed residential electric heating clusters as the research object, a dynamic model of temperature-varying power is established for electric heating rooms based on the building thermodynamics theory. Secondly, the impacts of household type differences and aggregated household proportions on the regulation capability of heating load clusters are investigated. A refined aggregation model for heating load clusters considering the differences of heterogeneous household types and aggregation structure is established, with adjustable electricity quantified as an indicator to measure the regulation potential of heating load clusters. Then, a master-slave game model is constructed with the load aggregator (LA) as the leader and cluster users as followers. The quantified adjustable electricity of load clusters is incorporated into the game model as flexible resources to participate in demand response. The upper-level game model establishes an LA pricing model to formulate electricity scheduling plans and optimal heating electricity prices within the system, while the lower-level develops a user payment cost model where users determine their heating schedules based on the electricity prices. Finally, case studies verify that the proposed game model can effectively stimulate the demand response potential of users with the differences of heterogeneous household type, achieving economic benefits for both LA and users. © 2025 Automation of Electric Power Systems Press. All rights reserved.

关键词： Cooling

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Power grid transformer vibration-noise coupling effect considering subway stray current interference

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Dianli Xitong Baohu yu Kongzhi/Power System Protection and control 2025年第9期53卷 70-81页

作者： Pan, Chao An, Jingge Liu, Chuang Li, Zaiyuan Shi, Xiaobo Du, Yi Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Northeast Electric Power University Ministry of Education Jilin132012 China Dalian Power Supply Company State Grid Dalian Electric Power Co. Ltd. Dalian116001 China

To address the abnormal vibration and noise in power grid transformers caused by stray currents from urban subways, a transformer instability identification method based on the mapping relationship between stray current variations and inherent noise is proposed. First, the primary paths and mechanisms of stray current interference in the power grid are analyzed, and the characteristics of the stray current variations are summarized based on measured data. Next, a multi-physics transformer coupling model considering stray current interference is proposed, dividing the electromagnetic-mechanical-acoustic coupling into an electromagnetic interference domain and a vibration-noise propagation domain. Through simulation analysis under different scenarios, the interference and propagation patterns of stray current mutation rate and timing on transformer parameters such as current and magnetic flux are studied. Finally, an experimental platform is set up to measure the multi-physics characteristics of transformers, while the correctness of the proposed model and conclusions are verified by comparing experimental and simulation results. Moreover, an instability criterion is established based on the mapping between the stray current mutation rate and noise. The results indicate that the vibration and noise of the transformer intensify significantly at points of stray current mutation, with the problem being most severe when the phase angle difference between the stray current mutation timing and the initial phase of power frequency excitation is 90°, leading to an approximately 10% increase in the inherent noise level. This method provides a basis for situational awareness and equipment protection of grid transformers near rail transit systems. © 2025 Power System Protection and control Press. All rights reserved.

关键词： Transformer protection

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Analysis of Frequency Dynamic Distribution Characteristics in Chain-structured Power System with Renewable Energy Integration

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Dianli Xitong Zidonghua/Automation of Electric Power Systems 2025年第10期49卷 49-57页

作者： An, Jun Shi, Yan Cao, Shuai Zhou, Yibo Li, Kexin Zhang, Wanxiang Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin132012 China Northeast Branch of State Grid Corporation of China Shenyang110179 China

The integration of renewable energy generation, represented by wind power, into the power system has a significant impact on frequency security, and the characteristics of frequency distribution have gradually become a focal point of attention. To study the influence of wind power integration into multi-machine systems on frequency distribution characteristics, based on the frequency response characteristics of the"grid, source, and load"sides, this paper constructs an analytical model of the frequency response distribution characteristics of a multi-machine system with wind power, and analyzes the impact mechanism of wind power integration on the frequency distribution characteristics. Then a multi-dimensional quantification index system is developed to describe the relative dispersion and absolute differences in frequency response. Next, the validity of the mechanism model is verified using a simple chain-structured power system with"generation-transmission-reception", and the influence rules of electrical distance, wind power integration location, and disturbance location on the frequency distribution characteristic indices are analyzed. Finally, the influence rules of distribution characteristics are analyzed and verified in an actual large-scale power system with a high proportion of renewable energy. © 2025 Automation of Electric Power Systems Press. All rights reserved.

关键词： Wind power integration

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Lithium-Ion Battery Health state Prediction Based on Improved War Optimization Assisted-Long and Short-Term Memory Network

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Energies 2025年第9期18卷 2326-2326页

作者： Wei, Xiankun Mo, Mingli Peng, Silun School of New Energy Vehicles Chongqing Technology and Business Institute Chongqing401520 China State Key Laboratory of Automotive Simulation and Control Jilin University Changchun130022 China

It is essential that the state of health (SOH) for lithium-ion batteries is measured to ensure the safety and reliability of electric vehicles. However, an accurate prediction of SOH is still an art due to the complex degradation mechanisms. To address this challenge, a SOH prediction model based on Warfare Strategy Optimization-assisted hybrid mutual information in-former-Long Short-Term Memory neural network (IWSO-MILSTM) is proposed. First, both direct and virtual health indicators are derived from battery degradation curves. Building on this foundation, mutual information is applied to the correlation analysis of these health indicators, and the redundant health indicators can be filtered. Then, the selected health indicators are fed into the informer-LSTM to construct an interpretable predicted model for the health status of lithium-ion batteries. Notably, both redundancy of health indicators and the imprecision of model hyperparameters for LSTM affect the SOH prediction precision. IWSO is proposed to achieve co-optimization of filtering for health indicators and hyperparameters for the informer-LSTM based on developed initializing distribution methods and adaptive function so that the SOH prediction precision is ensured. Finally, the NASA dataset is used to validate the prediction precision of the IWSO-MILSTM, and the experimental results show that the IWSO-MILSTM can provide more competitive results, i.e., the R2 value is improved by 25.68% and 3.63%, respectively, while the RMSE is reduced by 48.76% and 75.91% compared with XGBoost, LSTM, etc. Such results indicate the proposed method can predict SOH efficiently. © 2025 by the authors.

关键词： Lithium-ion batteries

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Publisher Erratum: Design of energy-saving driving strategy based on proximal policy optimization considering urban transport information(control Theory and Technology, (2025), 23, (74–90), 10.1007/s11768-024-00233-7)

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control Theory and Technology 2025年

作者： Liu, Qifang Sun, Dazhen Chen, Haowen Li, Dongzi Wang, Ping Department of Control Science and Engineering Jilin University Jilin Changchun130022 China State Key Laboratory of Automotive Simulation and Control Jilin University Jilin Changchun130022 China

In this article, the received, revised and accepted dates are missing. Please find the correct history dates here: Received: 15 October 2023. Revised: 20 March 2024. Accepted: 6 May 2024. © The Author(s), under exclusive licence to South China University of Technology and Academy of Mathematics and Systems Science, Chinese Academy of Sciences 2025.

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Design and Optimization for the Occupant Restraint System of Vehicle Based on a Single Freedom Model

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Chinese Journal of Mechanical Engineering 2013年第3期26卷 492-497页

作者： ZHANG Junyuan MA Yue CHEN Chao ZHANG Yan State Key Laboratory of Automobile Simulation and Control Jilin University

Throughout the vehicle crash event, the interactions between vehicle, occupant, restraint system (VOR) are complicated and highly non-linear. CAE and physical tests are the most widely used in vehicle passive safety development, but they can only be done with the detailed 3D model or physical samples. Often some design errors and imperfections are difficult to correct at that time, and a large amount of time will be needed. A restraint system concept design approach which based on single-degree-of-freedom occupant-vehicle model (SDOF) is proposed in this paper. The interactions between the restraint system parameters and the occupant responses in a crash are studied from the view of mechanics and energy. The discrete input and the iterative algorithm method are applied to the SDOF model to get the occupant responses quickly for arbitrary excitations (impact pulse) by MATLAB. By studying the relationships between the ridedown efficiency, the restraint stiffness, and the occupant response, the design principle of the restraint stiffness aiming to reduce occupant injury level during conceptual design is represented. Higher ridedown efficiency means more occupant energy absorbed by the vehicle, but the research result shows that higher ridedown efficiency does not mean lower occupant injury level. A proper restraint system design principle depends on two aspects. On one hand,the restraint system should lead to as high ridedown efficiency as possible, and at the same time, the restraint system should maximize use of the survival space to reduce the occupant deceleration level. As an example, an optimization of a passenger vehicle restraint system is designed by the concept design method above, and the final results are validated by MADYMO, which is the most widely used software in restraint system design, and the sled test. Consequently, a guideline and method for the occupant restraint system concept design is established in this paper.

关键词： vehicle crash occupant restraint system concept design single-degree-of-freedom occupant-vehicle model

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