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Bimodal microstructure – A feasible strategy for high-strength and ductile metallic materials

Journal of Materials Science & Technology 2018年第2期34卷 257-264页

作者： Min Zha Hong-Min Zhang Zhi-Yuan Yu Xuan-He Zhang Xiang-Tao Meng Hui-Yuan Wang Qi-Chuan Jiang State Key Laboratory of Automotive Simulation and Control Jilin University Key Laboratory of Automobile Materials of Ministry of Education & School of Materials Science and Engineering Nanling Campus Jilin University

Introducing a bimodal grain-size distribution has been demonstrated an efficient strategy for fabricating high-strength and ductile metallic materials, where fine grains provide strength, while coarse grains enable strain hardening and hence decent ductility. Over the last decades, research activities in this area have grown enormously, including interesting results onfcc Cu, Ni and Al-Mg alloys as well as steel and Fe alloys via various thermo-mechanical processing approaches. However, investigations on bimodal Mg and other hcp metals are relatively few. A brief overview of the available approaches based on thermo- mechanical processing technology in producing bimodal microstructure for various metallic materials is given, along with a summary of unusual mechanical properties achievable by bimodality, where focus is placed on the microstructure-mechanical properties and relevant mechanisms. In addition, key factors that influencing bimodal strategies, such as compositions of starting materials and processing parameters, together with the challenges this research area facing, are identified and discussed briefly.

关键词： Nanocrystalline and ultrafine-grained metals Mechanical milling Severe plastic deformation Bimodal microstructure Strength and ductility

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Impact of mixed benzene site exposure on bioaccessibility in simulated lung fluids and health risk assessment

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Journal of Hazardous Materials 2025年 494卷 138466页

作者： Ma, Xuemin Wang, Ying Chen, Shuhe Wu, Changyong Wang, Weipeng Wang, Yue Engineering Research Center of Environmental Pollution Control Chinese Research Academy of Environmental Sciences Beijing100012 China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences Beijing100012 China State Key Laboratory of Environmental Criteria and Risk Assessment and State Environmental Protection Key Laboratory of Simulation and Control of Groundwater Pollution Chinese Research Academy of Environmental Sciences Beijing100012 China College of Urban and Rural Construction Agricultural University of Hebei Baoding071001 China

Benzene series (BTEX) are predominant volatile organic compounds (VOCs) in petroleum production and downstream industrial sites, primarily enter human lungs via inhalation, posing significant health risks. To address the critical limitation of existing risk assessments that focus solely on individual components, this study investigated benzene and ethylbenzene based on contamination characteristics of petroleum refineries in Northwest China. An innovative in vitro membrane oxygenator system was developed to simulate single and mixed exposure scenarios at three soil concentrations: low (5 mg/kg), medium (10 mg/kg), and high (20 mg/kg), respectively. Health risk indices including inhalation risk (Inh), hazard quotient (HQ), and lifetime cancer risk (LCR) were calculated using bioaccessibility–adjusted parameters to precisely compare risk variations across exposure modes. Results demonstrated significant synergistic effects in gas-liquid mass transfer kinetics under mixed exposure (P © 2025 The Authors

关键词： Health risks

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PHYSICAL VALUE MAPPING ALGORITHM OF MESH IN FINE CAE ANALYSIS OF automobile BODY STRUCTURE

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Chinese Journal of Mechanical Engineering 2005年第3期18卷 338-341页

作者： Hu Ping Gong Kejia Bao Yidong State Key Laboratory of Automobile Dynamic Simulation Jilin University Changchun 130025 ChinaState Key Laboratory of Automobile Dynamic Simulation Jilin University Changchun 130025 China

A physical value mapping （PVM） algorithm based on finite element mesh from the stamped part in stamping process to the product is presented, In order to improve the efficiency of the PVM algorithm, a search way from the mesh of the product to the mesh of the stamped part will be adopted. At the same time, the search process is divided into two steps： entire search （ES） and local search （LS）, which improve the searching efficiency. The searching area is enlarged to avoid missing projection elements in ES process. An arc-length method is introduced in LS process. The validity is confirmed by the results of the complex industry-forming product.

关键词： Fine CAE analysis of auto body structure Finite element mesh Arc method Physical value mapping

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Effects of Cr and Mo elements on the microstructures and compressive properties of the in situ (TiCxNy–TiB2)/Ni cermets

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Progress in Natural Science:Materials International 2019年第1期29卷 20-27页

作者： Fang Chang Feng Qiu Chuanlu Li Yawei Wang Qichuan Jiang State Key Laboratory of Automotive Simulation and Control Jilin University Key Laboratory of Automobile Materials Ministry of Education and Department of Materials Science and Engineering Jilin University

In-situ(TiCN–TiB)/Ni cermets with 70 wt%TiCN–TiBwere successfully fabricated by combustion synthesis and hot pressing sintering in Ni-Ti-BC-BN powder *** microstructures,density,compressive properties,and hardness of the TiCN–TiB/Ni cermets with the addition of 0–8 wt%Cr/Mo to the Ni-Ti-BC-BN powder systems were compared and *** results showed that the ceramic particles distributed uniformly in the cermets,and the size of the ceramic particles reduced with the Cr/Mo *** Cr and Mo addition can improve the hardness,compressive properties,and fracture strains of the *** hardness,compressive strength,and fracture strain of the(TiCN–TiB)/(Ni+Cr)cermets increased from 1561 HV,2.94 GPa,and 2.9%to 1864 HV,3.65 GPa,and 3.4%,respectively when the Cr content increased to 5 wt%.The hardness and compressive strength of the(TiCN–TiB)/(Ni+Mo)cermets increased from 1561 HV and 2.94 GPa to 1902 HV and 3.43 GPa,respectively when the Mo content increased to 8 wt%.The cermets with Cr had better compressive properties than the cermets with Mo.

关键词： (TiCxNy–TiB2)/Ni cermets Cr/Mo content Microstructure Compressive properties

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A MODIFIED ALGORITHM FOR DEALING WITH HOLDER FRICTION BOUNDARY CONDITION IN simulation OF SHEET METAL FORMING

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Acta Mechanica Solida Sinica 2005年第3期18卷 272-277页

作者： Na Jingxin Shen Guozhe Liu Haipeng Hu Ping State Key Laboratory of Automobile Dynamic Simulation College of Automobile Engineering Jilin University Changchun 130022 China

This paper investigates the equivalent model for the friction boundary condition between blank and holder during sheet metal forming simulation, and proposes an equivalent algorithm, the thickness threshold value algorithm, for the first time based on thickness weighting. This algorithm assumes that the holder clearance is uniform during sheet metal forming; and the main reason for the unevenness of friction force distribution under the holder is that the uneven deformation of the blank leads to its uneven thickness distribution, which makes the local pressure on the blank distributed unevenly. The algorithm proposed in this paper can effectively simulate the influence of the unevenness on the forming process. Validity of this algorithm is verified by a comparison between the simulation results and the experimental ones for the drawing process of a car spring base.

关键词： thickness threshold value holder friction sheet metal forming

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High Abundance of Atmospheric Sulfonates Derived from Light-Duty Gasoline Vehicles

ACS ES&T Air

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ACS ES&T Air 2025年第4期2卷 607-614页

作者： Shuang Chen Huixia Han Lihong Ren Yisheng Xu Libin Wu Yuanguan Gao Yuanbi Yi Xinping Yang Mingliang Fu Hang Yin Yan Ding Pingqing Fu State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences Beijing 100012 China；School of Earth System Science Tianjin University Tianjin 300072 China School of Earth System Science Tianjin University Tianjin 300072 China State Key Laboratory of Environmental Criteria and Risk Assessment Chinese Research Academy of Environmental Sciences Beijing 100012 China Department of Ocean Science and Center for Ocean Research in Hong Kong and Macau The Hong Kong University of Science and Technology Hong Kong SAR China State Environmental Protection Key Laboratory of Vehicle Emission Control and Simulation Chinese Research Academy of Environmental Sciences Beijing 100012 China

Particulate matter (PM) emissions from light-duty gasoline vehicles (LDGV) pose a threat to both air quality and human health. However, the molecular compositions and chemical properties of these complex mixtures are poorly understood. In this study, we performed a detailed characterization of exhaust PM from LDGV at various speed phases at the molecular level by employing ultra-high-resolution Fourier transform ion cyclotron resonance mass spectrometry. We found that with increasing speed, the number of organic compounds increased significantly, especially organic nitrogen-containing and sulfur-containing compounds. Moreover, the increase of speed leads to high temperature and high pressure in the cylinder, which in turn leads to a series of thermal cracking–polymerization–cyclization reactions, resulting in new particulate matter with more aromatic structures. In addition, considerable intermediate volatility organic compounds and semivolatile organic compounds were identified in the exhaust PM. Notably, we observed the presence of sulfonates in tailpipe particulate matter during low- or high-speed phases, which highlights a previously negligible source of organic sulfonates in the atmosphere.

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N-Nitrosamines in Karst Groundwaters in Southwestern China: Risks and Implications for Drinking Water Safety

SSRN

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SSRN 2025年

作者： Gu, Xiongwei Xu, Liwei Huang, Xin Chen, Yingjie Shan, Yuanyu Yan, Xiaoyu Liu, Zhaojue Zeng, Hong-Hu Chen, Wenwen Huang, Huanfang Guangxi Key Laboratory of Environmental Pollution Control Theory and Technology Guilin University of Technology Guilin541006 China Engineering Research Center of Watershed Protection and Green Development University of Guangxi Guilin University of Technology Guilin541006 China State Environmental Protection Key Laboratory of Water Environmental Simulation and Pollution Control South China Institute of Environmental Sciences MEE Guangzhou510535 China SCNU Environmental Research Institute Guangdong Provincial Key Laboratory of Chemical Pollution and Environmental Safety & MOE Key Laboratory of Theoretical Chemistry of Environment South China Normal University Guangzhou510006 China

Groundwater is a vital drinking water source for populations in remote karst regions. However, the highly developed karst tube systems facilitate the infiltration of surface wastewater containing N-nitrosamines, raising concerns about groundwater safety. To assess the safety of groundwater and identify which types are safer for consumption, this study investigated N-nitrosamines in various groundwater types, including ground river, karst cavern, well, and mountain spring waters, in Guangxi, a typical karst region in southwestern China. The total concentrations of eight N-nitrosamines in groundwater ranged from 5.1 to 70.3 ng/L, with N-nitrosodiethylamine (NDEA), N-nitrosodimethylamine (NDMA), and N-nitrosopyrrolidine (NPYR) being the dominant species. Ground river water exhibited significantly higher N-nitrosamine concentrations than karst cavern, well, and mountain spring waters. Significant correlations between N-nitrosamines and dissolved inorganic nitrogen suggested their co-emissions from domestic wastewater and the secondary formation potential of N-nitrosamines in groundwater. Redundancy analysis further identified domestic and swine wastewater as the primary sources. Ground river and mountain spring waters posed the highest risks among the four groundwater types, with 30% and 20% of sites, respectively, exceeding acceptable cancer risk thresholds. These findings underscore the importance of thorough water treatment before groundwater is used for drinking. Strict livestock farming and domestic wastewater discharge regulations are essential to mitigate contamination risks, particularly in karst areas. © 2025, The Authors. All rights reserved.

关键词： Nitrosamines

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Polyethylene microplastics hamper aged biochar’s potential in mitigating greenhouse gas emissions

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Carbon Research 2025年第1期4卷 1-14页

作者： Chen, Yalan Wang, Zhibo Zhang, Anqi Li, Yang Sun, Ke Jiang, Chenrun Gunina, Anna Aloufi, Abeer S. Liang, Xinru Han, Zichen Xiao, Yue Zhang, Yunqian Du, Zhangliu Zhu, Shishu Kuzyakov, Yakov State Key Laboratory of Water Environment Simulation School of Environment Beijing Normal University Beijing100875 China College of Life Sciences Beijing Normal University Beijing100875 China Department of Urban Engineering Graduate School of Engineering The University of Tokyo Tokyo113-8656 Japan Agrarian and Technological Institute RUDN University Miklukho-Maklaya st. 6 Moscow117198 Russia Department of Biology College of Science Princess Nourah Bint Abdulrahman University P.O. Box 84428 Riyadh11671 Saudi Arabia Beijing Key Laboratory of Biodiversity and Organic Farming College of Resources and Environmental Sciences China Agricultural University Beijing100193 China The Key Lab of Pollution Control and Ecosystem Restoration in Industry Clusters Ministry of Education School of Environment and Energy South China University of Technology Guangzhou510006 China Department of Soil Science of Temperate Ecosystems Department of Agricultural Soil Science University of Goettingen Göttingen37077 Germany Moscow117198 Russia

While biochar effectively reduces greenhouse gas emissions, the coincident microplastics will alter these benefits. To assess the long-term efficacy of biochar application in reducing emissions amidst microplastic interference, we investigated the interactive effects of polyethylene microplastics (1%–5% wt) and decadal biochar addition (aged biochar) on C and N stability in a Fluvic Cambisol. Aged biochar and polyethylene individually reduced CO2 emissions by 49% and 18%, respectively, over 91-day incubation. This was due to decreased soil aggregation, dissolved organic matter (DOM) content, and increased DOM aromaticity, which reduced microbial biomass and chitinase activity associated with soil organic matter (SOM) decomposition. This ultimately led to increased accumulation of microbial necromass carbon (MNC) to soil stable carbon pool. Interestingly, the coexistence of polyethylene diminished the efficacy of biochar in mitigating CO2 emissions (+ 44 ~ 82%) and stabilizing MNC (-18 ~ 23%). This was because the interaction between polyethylene and biochar facilitated macroaggregate formation and DOM accumulation and decreased DOM aromaticity, which increased microbial biomass and chitinase activity for SOM decomposition. Similar to soil C dynamics, aged biochar largely reduced N2O emissions by 54%, due to decreased nirK but increased nifH genes. Polyethylene increased N2O emissions by 5% and 25% in biochar-free and aged biochar soil, respectively, likely through upregulation of nirS and nirK but downregulating nifH gene expression. Thus, polyethylene microplastics may undermine the benefits of biochar in mitigating climate change, highlighting the necessity to recognize microplastics as a global change factor and to incorporate their role in elemental cycling alongside their global transport. Graphic Abstract: (Figure presented.) © The Author(s) 2025.

关键词： Greenhouse gas emissions

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Historical inventories and future scenarios of multiple hazardous air pollutants (HAPs) emissions from the iron and steel production industry in China

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Science of the Total Environment 2025年 958卷 178051页

作者： Yang, Junqi Tian, Hezhong Fu, Zhiqiang Bai, Xiaoxuan Wang, Kun Liu, Wenjun Lu, Yiping Zhou, Yu Zhao, Hongyan Cui, Jiangyu Du, Qinwei State Key Joint Laboratory of Environmental Simulation & Pollution Control School of Environment Beijing Normal University Beijing100875 China Center for Atmospheric Environmental Studies Beijing Normal University Beijing100875 China Beijing100045 China Institute of Urban Safety and Environmental Science Beijing Academy of Science and Technology Beijing100054 China

Iron and steel production (ISP) is one of significant atmospheric pollution emission sources in China. With the implementation of ultra-low emission (ULE) standards, a detailed and new updated emission inventory is urgently needed for better understanding of the temporal trends and spatial variation of emission characteristics. In this study, a unit-based comprehensive emission inventory of multiple hazardous air pollutants (HAPs) for the Chinese ISP spanned from 2012 to 2021, including the conventional pollutants, 13 kinds of Trace elements as well as 2 unconventional but toxic pollutants (PCDD/Fs, F), was dedicatedly developed by integrating dynamic localized emission factors with unit-based information of both the detailed activity level and abatement technology application. Scenario analyses were also conducted to forecast future emission trends up to 2050. The results showed that the lower emission factors owing to ULE retrofits had resulted in different spatial-temporal emission characteristics between outputs and HAPs emissions. The atmospheric emissions of SO2, NOX, PM2.5, PM10, TSP, F and PCDD/Fs from Chinese ISP in 2021 were estimated at about 414.4, 450.5, 1044.3, 2001.6, 3958.8, 9.42 kt and 9.35 kg-TEQ, respectively. And most HAPs emissions were lower than those in 2012. Regarding the spatial distribution, Hebei, Jiangsu, Shanxi, ranked as the top 3 emission provinces. Moreover, different manufacturing processes (sintering, blast furnace, steel making, etc.) contributed with different magnitude for specific species, and the future trends estimation showed a great reducing potential caused by the implementation of ULE abatement measures and structure adjustment in future. © 2024 Elsevier B.V.

关键词： Iron and steel industry

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Weight Scheduling Model Predictive control for Gear Shift of a 2-Speed Electric Vehicle 34

Weight Scheduling Model Predictive Control for Gear Shift of...

引用

第三十四届中国控制会议

作者： YE keyu LIU Qifang GAO Bingzhao CHEN Hong Department of Control Science and Engineering State Key Laboratory of Automobile Dynamic Simulation

ISBN: (纸本)9781467374439

A weight scheduling model predictive controller is proposed for gear shift of an electric vehicle with a 2-speed IAMT. In the inertia phase, the contradictory control objectives of less friction work and smooth transmission output torque are included in the objective function, which aims to improve shift quality. In order to trade off contradictory requirements, a set of suitable weighting factors are chosen to solve this gear shift control problem. The designed weight scheduling model predictive controller is tested with a complete simulation model of powertrain system in the nominal conditions under different acceleration commands and in the changed conditions. The simulation results verified that the proposed controller can provide satisfactory performance even under uncertainties of vehicle mass and road grade.

关键词： Gear Shifting,2-Speed AMT,Weight Scheduling Model Predictive control,Electric Vehicle

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