检索结果-内蒙古大学图书馆

Nucleophilic cleavage of C-F bonds by Brùnsted base for rapid synthesis of fluorophosphate materials

National Science Review 2025年第3期 292-303页

作者： Qingfeng Fu Zihao Chang Peng Gao Wang Zhou Hongliang Dong Peifeng Huang Aiping Hu Changling Fan Peitao Xiao Yufang Chen Jilei Liu College of Materials Science and Engineering Hunan Joint International Laboratory of Advanced Materials and Technology for Clean Energy Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology Hunan University State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Center for High Pressure Science and Technology Advanced Research State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of Ceramics Chinese Academy of Sciences College of Aerospace Science and Engineering National University of Defense Technology

Fluorochemicals are a rapidly expanding class of materials used in a variety of fields including pharmaceuticals, metallurgy, agrochemicals, refrigerants, and in particular, alkali metal ion ***, achieving one-step synthesis of pure fluorophosphate compounds in a well-controlled manner remains a formidable challenge due to the volatilization of fluorine during the heat treatment process. One feasible method is to cleave the C–F bond in polytetrafluoroethylene（PTFE） during synthesis to create a fluorine-rich atmosphere and strongly reducing environment. However, the inert nature of the C–F bond in PTFE presents a significant obstacle, as it is the strongest single bond in organic compounds. To address this predicament, we propose a fluorine-compensating strategy that involves cleavage of the C–F bonds by nucleophilic SN2-type reactions of Br?nsted base（ammonia） enabling fluorine compensation. The decomposed products（NH2· and C·） also result in the formation of micropores（via NH3escape） and in-situ carbon coating（via C· polymerization）. The resultant cathode delivers a superior potassium storage capability including high rate performance and capacity retention. This contribution not only overcomes the obstacles associated with the inert C–F bond in fluororesin, but also represents a significant step forward in the development of fluorine-containing compounds.

关键词：

来源：评论

学校读者我要写书评

暂无评论

A review on aluminum matrix composites' characteristics and applications for automotive sector

引用

Heliyon 2024年第20期10卷 e38576页

作者： Wu, Xiaodong Zhang, Wenkang Changsha Normal University Changsha 410100 China State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan University Changsha 410082 China College of Engineering Anhui Agricultural University Hefei 230036 China

In recent years, the auto industry has experienced significant advancements, making research and development (R&D) of vehicle materials increasingly vital. Aluminum matrix composites (AMCs), known for their lightweight, high strength, and excellent corrosion resistance, have demonstrated substantial potential in vehicle aesthetics, interior trim, power systems, and components manufacturing. Currently, aluminum-metal composites (such as Cu and Mg) and aluminum-nonmetal composites (including Si, C, and plastics) are the primary types of AMCs used in automobiles. A thorough investigation into their preparation, process mechanisms, and performance optimization is essential for the broader application of AMCs in new vehicle models. This review summarizes and analyzes the preparation methods, wear mechanism, performance enhancement strategies, strengthening mechanism, and economic impact of AMCs, discussing key influential factors to foster the development of new AMCs. Additionally, by examining the role of aluminum compound packing films in the pouch batteries of Electric vehicles, also explores the future potential of AMCs within the new energy power sector. © 2024 The Authors

关键词： Aluminum matrix composites Aluminum-plastic film Mechanisms vehicle

来源：评论

学校读者我要写书评

暂无评论

Influence of Natural Aging on the Precipitation Behavior of Β″ Phase During the Artificial Aging Process in A357 Aluminum Alloys and Related Mechanisms

SSRN

引用

SSRN 2023年

作者： Wang, Tan He, Hong Liu, Ke Yan, Yong Deng, Zhichao Liao, Jiang Li, Wenjun State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle Engineering Hunan University Hunan Changsha410082 China Jianglu Machinery & Electronics Group Co. Ltd. Xiangtan411100 China China North Advanced Technology Generalization Institute Beijing100089 China

This study investigated the influence of natural aging (NA) on the precipitation behavior of the main precipitate β″ and hardness evolution during the subsequent artificial aging (AA) process of the precipitation strengthened A357 aluminum alloy. The related mechanisms were analyzed. The results demonstrate that natural aging has adverse effects on the precipitation process during artificial aging, resulting in an increase in the size and a decrease in the quantity of β″ phase precipitated during artificial aging. The mechanism underlying this adverse effect is that small GP zones are formed during natural aging but cannot become nucleation sites for the β″ phase during artificial aging, which spontaneously consumes the supersaturated solute atoms in the Al matrix, increases the nucleation barrier of the β″ phase, and also consumes the vacancies produced after solid solution and quenching, thereby reducing the nucleation rate of the β″ phase during artificial aging, and leading to an increase in the size of the precipitated phase, thus reducing its peak aging hardness of the alloy. This effect becomes more pronounced with increasing natural aging time, resulting in a lower peak aging hardness of the samples. Increasing the artificial aging temperature can improve the nucleation rate of the β″ phase during artificial aging, thereby to some extent reducing the unfavorable influence of natural aging on artificial aging by reducing the sizes of the β″ precipitates. © 2023, The Authors. All rights reserved.

关键词： Hardness

来源：评论

学校读者我要写书评

暂无评论

Integrated Schedule and Speed Optimization for Heterogeneous Multiple vehicles at Intelligent Signal-Free Intersections

引用

IEEE Transactions on Vehicular technology 2025年

作者： Cai, Jianjun Pan, Wenjun Li, Yang Que, Wenwei Chen, Xiutao Liu, Yonggang Chen, Zheng Chongqing University State Key Laboratory of Mechanical Transmission for Advanced Equipment Chongqing400044 China Dongfeng Liuzhou MOTOR Co. Ltd. Liuzhou545000 China Hunan University State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Changsha410082 China University of Malaya Faculty of Engineering Department of Mechanical Engineering Kuala Lumpur50603 Malaysia Kunming University of Science and Technology Faculty of Transportation Engineering Kunming650500 China

To mitigate energy consumption and travel delays for electric vehicles (EVs) and traditional fuel vehicles (FVs) at signal-free intersections, this paper presents a cooperative ecodriving approach integrating schedule and speed optimization for heterogeneous vehicles. Specifically, a cooperative optimization strategy is devised to optimize the arrival times of heterogeneous vehicles at a signal-free intersection. Furthermore, to enhance energy consumption economy and ride comfort of vehicles, a multi-objective eco-driving speed planning algorithm is designed to plan the vehicles' speed trajectory, in which the quadratic programming is employed for EVs and the Gauss Pseudospectral method for FVs. A rolling optimization framework is adopted to combine the schedule strategy and speed planning algorithm and enable real-time application of the proposed approach. Finally, the simulation results exhibit that compared to the scheme that combines the first-come-first-served method with linear programming, the proposed approach can improve travel efficiency by 54.95% and avoid collisions, while reducing the energy consumption of EVs and FVs by 24.81% and 51.72%, respectively, and observably improving vehicle ride comfort. Moreover, extensive sensitivity analyses are also conducted to demonstrate the energy-saving performance of the approach under various market penetration rates of EVs and traffic flow conditions. © 2025 IEEE.

关键词： Sensitivity analysis

来源：评论

学校读者我要写书评

暂无评论

A crystal plasticity-based constitutive model for ratchetting of cyclic hardening polycrystalline metals

引用

International Journal of Dynamics and Control 2020年第4期8卷 1161-1168页

作者： Ren, Xuehong Yang, Shaopu Zhao, Wenzhao Wen, Guilin State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Changsha410082 China State Key Laboratory of Mechanical Behavior in Traffic Engineering Structure and System Safety Shijiazhuang Tiedao University Shijiazhuang050043 China

A crystal plasticity-based constitutive model is developed by modifying the second item of ArmstrongFrederick (AF) nonlinear kinematic hardening rule and introducing self-hardening and latent hardening representing the dislocation interaction between slip systems. With the help of β scale-transition rule, the cyclic stressstrain responses of polycrystalline metals can be obtained from the single crystal constitutive model. Then the developed model is applied to describe the cyclic deformation behavior of a face-centered cubic polycrystalline metal, i.e., 316L stainless steel. The predicted results of the model compared with the experiments of 316L stainless steel show that the model can not only simulate the uniaxial and multiaxial ratchetting of the face-centered cubic crystal material during the asymmetrical stress-controlled cyclic loading, but also describe the cyclic hardening characteristics of materials under symmetrical strain-controlled cyclic loading. Meanwhile, the model is capable of predicting uniaxial ratchetting of different orientations at single crystal scale. © 2020, Springer-Verlag GmbH Germany, part of Springer Nature.

关键词： Constitutive models

来源：评论

学校读者我要写书评

暂无评论

Research of injury mapping relationship of lumbar spine in reclined occupants between anthropomorphic test devices and human body model

引用

中华创伤杂志(英文版) 2025年第2期

作者： Liu Yu Fei Jing Wan Xin-Ming Wang Pei-Feng Li Zhen Yang Xiao-Ting Zhang Lin-Wei Bai Zhong-Hao China Automotive Engineering Research Institute Co. Ltd. Chongqing China School of Vehicle and Mobility Tsinghua University Beijing China State Key Laboratory of Advanced Design and Manufacturing Technology for Vehicle Hunan University Changsha China

Purpose:To judge the injury mode and injury severity of the real human body through the measured values of anthropomorphic test devices (ATD) injury indices, the mapping relationship of lumbar injury between ATD and human body model (HBM) was ***:Through the ATD model and HBM simulation, the mapping relationship of lumbar injury between the 2 subjects was explored. The sled environment consisted of a semi-rigid seat with an adjustable seatback angle and a 3-point seat belt system with a seatback-mounted D-ring. Three seatback recline states of 25°, 45°, and 65° were designed, and the seat pan angle was maintained at 15°. A 23 g, 47 km/h pulse was used. The validity of the finite element model of the sled was verified by the comparison of ATD simulation and test results. ATD model was the test device for human occupant restraint for autonomous vehicles (THOR-AV) dummy model and HBM was the total human model for safety (THUMS) v6.1. The posture of the 2 models was adjusted to adapt to the 3 seat states. The lumbar response of THOR-AV and the mechanical and biomechanical data on L1 - L5 vertebrae of THUMS were output, and the response relationship between THOR-AV and THUMS was descriptive statistically ***:Both THOR-AV and THUMS were submarined in the 65° seatback angle case. With the change of seatback angle, the lumbar spine axial compression force (Fz) of THOR-AV and THUMS changed in the similar trend. The maximum Fz ratio of THOR-AV to THUMS at 25° and 45° seatback angle cases were 1.6 and 1.7. The flexion moment (My) and the time when the maximum My occurred in the 2 subjects were very different. In particular, the form of moment experienced by the L1 - L5 vertebrae of THUMS also changed. The changing trend of My measured by THOR-AV over time can reflect the changing trend of maximum stress of L1 and L2 of ***:The Fz of ATD and HBM presents a certain proportional relationship, and there is a mapping relationship between the 2

关键词： Reclined posture Lumbar spine injury Injury mapping Anthropomorphic test devices Human body model

来源：评论

学校读者我要写书评

暂无评论

Optical Investigation on Spray, Combustion and Flame Structure of N-Hexanol/Biodieselblends in a Constant Volume Chamber

SSRN

引用

SSRN 2024年

作者： Zhou, Feng Huang, Xinjia Fu, Jianqin Liu, Jingping Li, Gang College of Mechanical and Electrical Engineering Central South University of Forestry and Technology Changsha410004 China State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Changsha410082 China College of Mechanical and Electronic Engineering Northwest A&F University Yangling712100 China

N-hexanol has been regarded as a promising and potential oxygenated renewable fuel for diesel engines. However, most of the current studies on the application of n-hexanol were based on engine bench experiments, and although hexanol added to diesel fuel has a great effect on diesel fuel spray, combustion, and flame structure, there is no relevant experiments they are systematically investigated. Therefore, in this research, a constant volume chamber (CVC) system was used to comprehensively investigate the effects of n-hexanol on the spray, combustion and flame structure of soybean-based biodiesel. The spray distance and spray area of SH20 formed by the addition of hexanol were significantly smaller than those of S40 under most operating conditions, and the liquid penetration length was significantly increased, resulting in a significant improvement in spray characteristics. The analyses showed that the combustion duration was always shortened when hexanol was blended into biodiesel. In addition, the addition of a quantitative amount of hexanol not only reduced the SINL but also had a more pronounced effect on the flame characteristics than the addition of 40% soybean oil to diesel fuel alone under all conditions, suggesting that hexanol has a great potential to inhibit carbon soot generation and emissions. © 2024, The Authors. All rights reserved.

关键词： Soot

来源：评论

学校读者我要写书评

暂无评论

Sulfur Doped Hollow Carbon Nanofiber Anodes for Fast-Charging Potassium-Ion Storage

SSRN

引用

SSRN 2022年

作者： Wang, Fei Li, Du Zhang, Guanhua Li, Jingyuan Zhang, Chengzhi Wei, Donghai Yang, Jianxiao Ye, Chong Tan, Jun Liu, Jinshui State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle Engineering Hunan University Changsha410082 China Hunan Province Key Laboratory for Advanced Carbon Materials and Applied Technology College of Materials Science and Engineering Hunan University Changsha410082 China Ji Hua Laboratory Guangdong Foshan528000 China

Sulfur doping can bridge durable active sites, induce C-S electron coupling to produce unparalleled Faraday conversion, break the limitations of ion storage capacitance, and therefore is an effective way to design carbon materials with improved electrochemical performance. However, sulfur doping mechanism, especially how to design S-rich by atomic transition among carbon membered-ring structure of anodes remains a confusing topic. Herein, the linear relationship between sulfur and nitrogen content is found, and the tendency of sulfur to replace pyrrolic nitrogen is demonstrated. The sulfur replaces part of nitrogen atoms and form C-S bonds with binds covalently to carbon skeleton, where S-rich hollow carbon nanofibers (NHCFs-S) are synthesized. The introduction of high S-doping in carbon results to the improvement of conductivity, Faraday reaction activity and pseudocapacitive adsorption behavior. For potassium-ion batteries, the fabricated NHCFs-S material delivers a 369 mAh g−1 high capacity at 1.0 A g−1 after 100 cycles with 80% initial coulombic efficiency and a desirable rate capability of 261 mAh g−1 even at 5.0 A g−1. This work provides a selection for high-performance anodes design and a reference for the future research of high sulfur doped in carbon materials. © 2022, The Authors. All rights reserved.

关键词： Sulfur

来源：评论

学校读者我要写书评

暂无评论

Simultaneous Improvement of Mechanical and Castability Properties of Al-Cu-Mn Based Alloys by Ca/Ni Micro-Alloying

SSRN

引用

SSRN 2024年

作者： Su, Zhanwei Jin, Chen Zeng, Zhuoran Zhang, Sai Meng, XianMing Xu, Shiwei State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Changsha410082 China Qinghai Saltlake Trimag Co. LTD China College of Materials Science and Engineering Hunan University Changsha410082 China China Automotive Technology&Research Center Co. Ltd China

AbstractCurrently one major barrier for the design of cast high-strength and high-toughness Al alloys is hot tearing. In this work, a strategy of combination of squeeze casting and microalloying in Al-Cu-Mn based alloys was employed to inherit the excellent mechanical properties of Al-Cu alloys whilst simultaneously reducing their tendency to hot tearing. Trace Ca/Ni additions markedly reduce the grain size of the alloy and simultaneously increase the fraction of intergranular low melting point eutectic liquid phases. The fine equiaxed grains have excellent thermal shrinkage coordination, while the eutectic liquid phase delays the development of grain cohesive skeleton. Accordingly, the localized shrinkage stress/strain at the hot spot is released timely, thus inhibiting the emergence and propagation of hot cracks in the brittle solidification interval. The diminished hot tearing susceptibility is attributed to the reduced load onset temperature and load values in the hot spot region. A new intergranular bridging mechanism is discovered in low-Ca alloys: based on compositional segregation-induced nucleation of an intergranular bridging skeleton, which strengthens the intergranular adhesive force and effectively reduces the hot tearing tendency of the alloys. The alloys with high-Ca/Ni additions, however, reduce the hot tearing tendency by healing cracks through eutectic liquid phase backfill. © 2024, The Authors. All rights reserved.

关键词： Manganese alloys

来源：评论

学校读者我要写书评

暂无评论

Micromechanisms Based Thermo-Magnetomechanical Properties of Magnetic Nanoparticles Enforced Elastomers for Thermo-Magnetically Triggered Shape Memory Properties

SSRN

引用

SSRN 2022年

作者： Zhang, Li Jiang, Kun Hou, Shujuan Tao, Ran Mao, Yiqi State Key Laboratory of Advanced Design and Manufacturing for Vehicle Body Hunan University Hunan Changsha410082 China Department of Engineering Mechanics College of Mechanical and Vehicle Engineering Hunan University Hunan Changsha410082 China Beijing Key Laboratory of Lightweight Multi-Functional Composite Materials and Structures Institute of Advanced Structure Technology Beijing Institute of Technology Beijing100081 China

Magnetic nanoparticles filled shape memory polymer (MSMP) have wide design scenarios and engineering applications due to their excellent functionalities of biological compatibility, physicochemical properties, and superior magnetic properties. The magneto-thermally activated shape memory process contains complex multi-physical mechanisms especially when coupled with finite deformation rooted on microscale states, where magnetic particles move under external magnetic fields and fluctuate the polymer chain networks. Considering two superimposed chain networks of magnetically crosslinked network and chemically crosslinked network, a sophisticated finite deformation model is developed in this work to get a deep understanding on the coupled magneto-thermomechanical properties of MSMP, beneficial to its design and wide application. The physically crosslinked network is formed by connected polymer chains between magnetic particles, and a uniformly distributed chain lengths is assumed for each particle pair. A damaged entropic elastic energy potential is developed in spirit of classical eight-chain network model to capture micro-physical mechanisms of nanoparticles interacting with double-chain networks where a continuous damage kinetic model is proposed to characterize gradual detachment of chain networks. The intact crosslinked chemical network is considered featuring with entropic-hyperelastic properties. The magneto-thermally triggered shape memory model is established applying viscous relaxation dissipation based magnetic-heating mechanism. The model is calibrated by a series of experiments, and then applied for the simulations of the isothermal uniaxial tension of MSMP with and without external magnetic fields, which demonstrate good feasibility of the model in capturing the coupled magneto-thermomechanical behavior of MSMP. The calibrated model is further utilized for magneto-thermally triggered shape recoveries by the magnetic-heating due to Neel and Brown relaxatio

关键词： Magnetic fields

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：