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Effect of microstructure on corrosion behavior of high strength martensite steel-A literature review

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International Journal of Minerals,Metallurgy and Materials 2021年第5期28卷 754-773页

作者： li Wang Chao-fang Dong Cheng Man ya-bo Hu qiang Yu Xiao-gang li Beijing Advanced Innovation Center for Materials Genome Engineering Key Laboratory for Corrosion and Protection(MOE)Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering Ocean University of ChinaQingdao 266100China Hunan Valin lianyuan Iron and Steel Co.Ltd Loudi 417009China

The high strength martensite steels are widely used in aerospace,ocean engineering,etc.,due to their high strength,good ductility and acceptable corrosion *** paper provides a review for the influence of microstructure on corrosion behavior of high strength martensite *** is the most common corrosion type of high strength stainless steels,which always occurs at weak area of passive film such as inclusions,carbide/intermetallic ***,the chromium carbide precipitations in the martensitic lath/prior austenite boundaries always result in intergranular *** precipitation,dislocation and grain/lath boundary are also used as crack nucleation and hydrogen traps,leading to hydrogen embrittlement and stress corrosion cracking for high strength martensite ***,the retained/reversed austenite has beneficial effects on the corrosion resistance and could reduce the sensitivity of stress corrosion cracking for high strength martensite ***,the corrosion mechanisms of additive manufacturing high strength steels and the ideas for designing new high strength martensite steel are explored.

关键词： corrosion behavior high strength martensite steel microstructure additive manufacturing

Hot Deformation and Dynamic Recrystallization Behavior of Austenite-Based Low-Density Fe–Mn–Al–C Steel

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Acta Metallurgica Sinica(English Letters) 2016年第5期29卷 441-449页

作者： ya-Ping li Ren-Bo Song Er-Ding Wen Fu-qiang yang School of Materials Science and Engineering University of Science and Technology BeijingBeijing 100083China R&D Center BAIC Motor Corporation LTDBeijing 101300China

The hot deformation and dynamic recrystallization （DRX） behavior of austenite-based Fe-27Mn-ll.5A1- 0.95C steel with a density of 6.55 g cm-3 were investigated by compressive deformation at the temperature range of 900-1150 ℃ and strain rate of 0.01-10 s-1. Typical DRX behavior was observed under chosen deformation conditions and yield-point-elongation-like effect caused by DRX of 6-ferrite. The flow stress characteristics were determined by DRX of the 6-ferrite at early stage and the austenite at later stage, respectively. On the basis of hyperbolic sine function and linear fitting, the calculated thermal activation energy for the experimental steel was 294.204 kJ mo1-1. The occurrence of DRX for both the austenite and the 6-ferrite was estimated and plotted by related Zener-Hollomon equations. A DRX kinetic model of the steel was established by flow stress and peak strain without considering dynamic recovery and 6-ferrite DRX. The effects of deformation temperature and strain rate on DRX volume fraction were discussed in detail. Increasing deformation temperature or strain rate contributes to DRX of both the austenite and the 6-ferrite, whereas a lower strain rate leads to the austenite grains growth and the 6-ferrite evolution, from banded to island-like structure.

关键词： Fe-Mn-AI-C steel Hot deformation Dynamic recrystallization Yield-point-elongation-likeeffect

Effects of seed aerosols on the growth of secondary organic aerosols from the photooxidation of toluene

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Journal of Environmental Sciences 2007年第6期19卷 704-708页

作者： HAO li-qing WANG Zhen-ya HUANG Ming-qiang FANG li ZHANG Wei-jun Laboratory of Environmental Spectroscopy Anhui Institute of Optics and Fine Mechanics Chinese Academy of Sciences Hefei 230031 China

Hydroxyl radical （.OH）-initiated photooxidation reaction of toluene was carried out in a self-made smog chamber. Four individual seed aerosols such as ammonium sulfate, ammonium nitrate, sodium silicate and calcium chloride, were introduced into the chamber to assess their influence on the growth of secondary organic aerosols （SOA）. It was found that the low concentration of seed aerosols might lead to high concentration of SOA particles. Seed aerosols would promote rates of SOA formation at the start of the reaction and inhibit its formation rate with prolonging the reaction time. In the case of ca. 9000 pt/cm^3 seed aerosol load, the addition of sodium silicate induced a same effect on the SOA formation as ammonium nitrate. The influence of the four individual seed aerosols on the generation of SOA decreased in the order of calcium chloride〉sodium silicate and ammonium nitrate〉ammonium sulfate.

关键词： toluene photooxidation secondary organic aerosol seed aerosol

四波混频Autler-Townes分裂中的探测光影响

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原子与分子物理学报 2025年第3期42卷 110-115页

作者：裴丽娅侯海龙北京化工大学数理学院北京100029

在双Λ-型四波混频系统中,研究了探测光强度对Autler-Townes(AT)分裂效应的影响.随着弱探测光强度增大,由缀饰态共振产生的AT分裂双峰间隔不变,但却逐渐增宽线宽且减弱直至消失;而在强耦合光失谐条件下,不对称地位于单光子共振峰两侧的A... 详细信息

在双Λ-型四波混频系统中,研究了探测光强度对Autler-Townes(AT)分裂效应的影响.随着弱探测光强度增大,由缀饰态共振产生的AT分裂双峰间隔不变,但却逐渐增宽线宽且减弱直至消失;而在强耦合光失谐条件下,不对称地位于单光子共振峰两侧的AT分裂双峰却会逐渐趋于对称分布.详细讨论了探测光场对原子的缀饰影响,提出通过探测光强度可以调控原子两基态之间的有效Raman相干,从而影响AT分裂双峰的特征.

关键词：四波混频原子相干 Autler-Townes分裂缀饰态横向弛豫率

维普期刊数据库博看期刊

State-chain sequential feedback reinforcement learning for path planning of autonomous mobile robots

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Journal of Zhejiang University-Science C(Computers and Electronics) 2013年第3期14卷 167-178页

作者： Xin MA ya XU Guo-qiang SUN li-xia DENG Yi-bin li School of Control Science and Engineering Shandong University

This paper deals with a new approach based on Q-learning for solving the problem of mobile robot path planning in complex unknown static *** a computational approach to learning through interaction with the environment,reinforcement learning algorithms have been widely used for intelligent robot control,especially in the field of autonomous mobile ***,the learning process is slow and *** practical applications,rapid rates of convergence are *** at the problem of slow convergence and long learning time for Q-learning based mobile robot path planning,a state-chain sequential feedback Q-learning algorithm is proposed for quickly searching for the optimal path of mobile robots in complex unknown static *** state chain is built during the searching *** one action is chosen and the reward is received,the Q-values of the state-action pairs on the previously built state chain are sequentially updated with one-step *** the increasing number of Q-values updated after one action,the number of actual steps for convergence decreases and thus,the learning time decreases,where a step is a state *** simulations validate the efficiency of the newly proposed approach for mobile robot path planning in complex *** results show that the new approach has a high convergence speed and that the robot can find the collision-free optimal path in complex unknown static environments with much shorter time,compared with the one-step Q-learning algorithm and the Q(λ)-learning algorithm.

关键词： Path planning Q-learning Autonomous mobile robot Reinforcement learning

A Rapid Crack Detection Technique Based on Attention for Intelligent M&O of Cross-Sea Bridge

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China Ocean Engineering 2024年第5期38卷 866-876页

作者： ZHOU Yong-chuan li Guang-jun WEI Wei WANG ya-meng JING qiang Hong Kong-Zhuhai-Macao Bridge Authority Zhuhai 519015China National Observation and Research Station of Material Corrosion and Structural Safety of Hong Kong-Zhuhai-Macao Bridge in Guangdong Zhuhai 519000China Wuhan Maritime Communication Research Institute Wuhan 430079China

Rapid and accurate segmentation of structural cracks is essential for ensuring the quality and safety of engineering *** practice,however,this task faces the challenge of finding a balance between detection accuracy and *** alleviate this problem,a lightweight and efficient real-time crack segmentation framework was ***,in the network model system based on an encoding-decoding structure,the encoding network is equipped with packet convolution and attention mechanisms to capture features of different visual scales in layers,and in the decoding process,we also introduce a fusion module based on spatial attention to effectively aggregate these hierarchical *** are connected by pyramid pooling model(PPM)*** results show that the crack segmentation accuracy and real-time operation capability larger than 76%and 15 fps,respectively,are validated by three publicly available *** wide-ranging results highlight the potential of the model for the intelligent O&M for cross-sea bridge.

关键词： bridge defect detection crack detection lightweight design

Solid rocket motor propellant grain burnback simulation based on fast minimum distance function calculation and improved marching tetrahedron method

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Chinese Journal of Aeronautics 2021年第4期34卷 208-224页

作者： Pengfei REN Hongbo WANG Guofeng ZHOU Jiani li qiang CAI Jiaquan YU ya YUAN China Academy of Launch Vehicle Technology Beijing 100076China School of Chemistry and Chemical Engineering Beijing Institute of TechnologyBeijing 100081China

To efficiently compute arbitrary propellant grain evolution of the burning surface with uniform and non-uniform burning rate for solid rocket motor,a unified framework of burning surface regression simulation has been developed based on minimum distance *** order to speed up the computation of the mini-mum distance between grid nodes of grain and the triangular mesh of burning surface,a fast distance querying method based on the equal size cube voxel structure was *** improved marching tetrahedron method based on piecewise linear approximation was carried out on second-order tetrahedral elements,achieved high-efficiency and adequate accuracy of burning surface extraction *** cases of star grain,finocyl grain,and non-uniform tube grain were studied to verify the proposed *** observed result indicates that the grain burnback computation method could realize the accurate simulation on unstructured tetrahedral mesh with a desirable performance on computational time.

关键词： Burning surface area Finocyl grain Level set Marching tetrahedron Minimum distance function Solid propellants Solid rocket motor

Geminal Cross Coupling (GCC) Reaction for AIE Materials

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Chinese Journal of Polymer Science 2019年第4期37卷 327-339,I0005页

作者： Qi Yu ya-Long Wang Ze-qiang Chen Peng-Ju Zhao Cheng Fan Chong li Ming-qiang Zhu Wuhan National Laboratory for Optoelectronics School of Optical and Electronic InformationHuazhong University of Science and Technology

Tetraphenylethylene(TPE) derivatives are typical aggregation-induced emission(AIE) molecules, which have been widely investigated and applicated. The Rathore's procedures and McMurry reaction are the two frequently used methods for synthesizing the TPE derivatives. The complex processes and low tolerance of active function groups make the TPE with limited structures and properties in some degree. Very recently, a novel strategy, named geminal cross coupling(GCC) reaction, is developed for designing and synthesizing various topological small molecules and polymers with rich optical properties beyond simple TPE compounds, and becomes a powerful synthesis method to AIE materials. This review overviews the current progresses of AIE molecules and polymers prepared by GCC as well as their applications. We believe that GCC reaction will have a bright future in the development of the next generation of tetraarylethylene(TAE)-kind AIE materials.

关键词： GCC reaction AIE Tetraarylethylene Conjugated polymer Imaging

“Zero‑Strain” NiNb_(2)O_(6) Fibers for All‑Climate lithium Storage

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Nano-Micro Letters 2025年第1期17卷 348-360页

作者： yan Zhao qiang Yuan liting yang Guisheng liang Yifeng Cheng limin Wu Chunfu lin Renchao Che College of Physics Donghua UniversityShanghai 201620People’s Republic of China School of Materials Science and Engineering Institute of Materials for Energy and EnvironmentQingdao UniversityQingdao 266071People’s Republic of China Laboratory of Advanced Materials Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsAcademy for Engineering&TechnologyFudan UniversityShanghai 200438People’s Republic of China Zhejiang Laboratory Hangzhou 311100People’s Republic of China Inner Mongolia University Hohhot 010021People’s Republic of China

Niobates are promising all-climate li^(+)-storage anode material due to their fast charge transport,large specific capacities,and resistance to electrolyte ***,their moderate unit-cellvolume expansion(generally 5%–10%)during li^(+)storage causes unsatisfactory long-term ***,“zero-strain”NiNb_(2)O_(6) fibers are explored as a new anode material with comprehensively good electrochemical *** li^(+)storage,the expansion of electrochemical inactive NiO_(6) octahedra almost fully offsets the shrinkage of active NbO_(6) octahedra through reversible O *** superior volume-accommodation capability of the NiO_(6) layers guarantees the“zero-strain”behavior of NiNb_(2)O_(6) in a broad temperature range(0.53%//0.51%//0.74%at 25//−10//60℃),leading to the excellent cyclability of the NiNb_(2)O_(6) fibers(92.8%//99.2%//91.1%capacity retention after 1000//2000//1000 cycles at 10C and 25//−10//60℃).This NiNb_(2)O_(6) material further exhibits a large reversible capacity(300//184//318 mAh g−1 at 0.1C and 25//−10//60℃)and outstanding rate performance(10 to 0.5C capacity percentage of 64.3%//50.0%//65.4%at 25//−10//60℃).Therefore,the NiNb_(2)O_(6) fibers are especially suitable for large-capacity,fast-charging,long-life,and all-climate lithium-ion batteries.

关键词： NiNb_(2)O_(6)porous fiber “Zero-strain”mechanism Electrochemical property Harsh-temperature operation Operando characterization