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Phase Transformation of a Cold Work Tool Steel during Tempering

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Journal of Iron and Steel Research International 2016年第5期23卷 484-488页

作者： Hong-xiao CHI Dang-shen MA Hui-xia XU wang-long zhu Jian-qing JIANG School of Materials Science and Engineering Southeast University Jiangsu Engineering Research Center of Tool and Die Steel Tiangong Group Institute for Special Steels Central Iron and Steel Research Institute

The hardness and microstructure evolution of a 8% Cr cold work tool steel during tempering for 40 h were investigated. Transmission electron microscope examinations showed that M_3C carbides precipitated from supersaturated martensite after tempering at 350 ℃. When the tempering temperature was higher than 520 ℃,the M_（23）C_6 carbides precipitated to substitute for M_3C carbides. After ageing at the temperature of 520 ℃ for 40 h,it was observed that very fine and dense secondary Mo_2C precipitates were precipitated. Thus,it can be concluded that the early stage of Mo_2C-carbide precipitation is like to be Gunier-Preston（ G-P） zone formed by [Mo-C] segregation group which is responsible for the secondary hardening peak at 520 ℃. Overageing at 700 ℃ resulted in recovery of martensitic microstructure and precipitation of M_（23）C_6 *** ageing at 700 ℃ for more than 20 h,recrystallization occurred,which resulted in a change of the matrix morphology from martensitic plates to equiaxed ferrite. It was noticed that the size of recrystallized grain / subgrain was very fine,which was attributed to the pinning effect of M_（23）C_6 precipitates.

关键词： cold work tool steel secondary hardening tempering carbide

A New Approach for Refining Carbide Dimensions in M42 Super Hard High-speed Steel

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Journal of Iron and Steel Research International 2016年第8期23卷 800-807页

作者： Xue-feng ZHOU wang-long zhu Hong-bing JIANG Feng FANG Yi-you TU Jian-qing JIANG Jiangsu Key Laboratory of Advanced Metallic Materials School of Materials Science and EngineeringSoutheast University Nanjing 211189 Jiangsu China Jiangsu Engineering Research Center of Tool and Die Steel Danyang 212312 Jiangsu China Nanjing University of Information Science and Technology Nanjing 210044 Jiangsu China

Obtaining small carbides is crucial but difficult for high-speed steels.A new approach for refining carbide dimensions in M42 super hard high-speed steel by increasing cooling rate and spheroidizing treatment was *** morphologies and properties of eutectic carbides formed at different cooling rates were investigated by means of scanning electron microscopy（SEM）,energy dispersive spectroscopy（EDS）,X-ray diffraction（XRD）,transmission electron microscopy（TEM）,electron back-scattered diffraction（EBSD）and differential scanning calorimeter（DSC）.The results show that eutectic carbides change from a lamellar shape into a curved-rod shape as cooling rate *** different morphologies,the two carbides are both of M2C type with a hexagonal close-packed structure and display a single crystal orientation in one eutectic *** morphology of M2C mainly depends on the growing process of eutectic carbides,which is strongly influenced by cooling *** with lamellar carbides,M2C carbides with curved-rod shapes are less stable,and decompose into M6 C and MC at lower *** are more inclined to spheroidize during heating,which ultimately and distinguishably refines the carbide *** small carbides are much easier to dissolve into matrices during austenization,the process described herein improves the supersaturation of alloying elements in martensite,which leads to an increment of hardness in M42 steel.

关键词： eutectic lamellar hexagonal carbide heating calorimeter curved dispersive dimensions decompose

Cyano migration-mediated radical-polar crossover cyclopropanation

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Science China Chemistry 2025年第1期68卷 241-248页

作者： Ziqiang wang Yasu Chen Jie Li Chen zhu Key Laboratory of Organic Synthesis of Jiangsu Province College of Chemistry Chemical Engineering and Materials ScienceSoochow University Frontiers Science Center for Transformative Molecules Zhangjiang Institute for Advanced Study and Shanghai Key Laboratory for Molecular Engineering of Chiral Drugs Shanghai Jiao Tong University

We report a novel cyano migration-mediated radical-polar crossover process, whereby both the sulfonylcyanation of aliphatic alkenes and the formation of cyclopropanes are concurrently achieved. This transformation yields a diverse array of multisubstituted cyclopropanes under mild photocatalytic conditions. Mechanistic studies elucidate that the reaction proceeds via intramolecular nucleophilic substitution, leading to the formation of the cyclopropane derivatives.

关键词： cyclopropanation cyano migration radical-polar crossover radical reactions

Recent advances of metal vacancies in energy and environmental catalysis:Synthesis,characterization,and roles

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Green Energy & Environment 2025年第1期10卷 84-108页

作者： long Sun Shunzheng Zhao Sirui Gao Ronghui zhu Yiran Tan Xiaolong Tang Honghong Yi School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing100083China Beijing Key Laboratory of Resource-oriented Treatment of Industrial Pollutants Beijing100083China

With the ongoing depletion of fossil fuels,energy and environmental issues have become increasingly critical,necessitating the search for effective ***,being one of the hallmarks of modern industry,offers a promising avenue for ***,the question of how to significantly enhance the performance of catalysts has gradually drawn the attention of *** engineering,a commonly employed and effective approach to improve catalyst activity,has become a significant research focus in the catalysis field in recent *** vacancies have received extensive attention due to their simple ***,exploration of metal vacancies has remained stagnant for a considerable period,resulting in a scarcity of comprehensive reviews on this ***,based on the latest research findings,this paper summarizes and consolidates the construction strategies for metal vacancies,characterization techniques,and their roles in typical energy and environmental catalytic ***,it outlines potential challenges in the future,aiming to provide valuable references for researchers interested in investigating metal vacancies.

关键词： Metal vacancies Catalysis Construction strategies Characterization techniques Roles

Effect of pyrite content on chalcopyrite flotation under different regrinding conditions

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International Journal of Minerals,Metallurgy and Materials 2025年第1期32卷 49-57页

作者： Zejun wang Qing Shi Guofan Zhang Yuxuan zhu Binbin Li School of Minerals Processing and Bioengineering Central South UniversityChangsha 410083China Key Laboratory of Hunan Province for Clean and Efficient Utilization of Strategic Calcium-containing Mineral Resources Central South UniversityChangsha 410083China

This study aimed to investigate the effect of varying pyrite(Py)content on copper(Cu)in the presence of different regrinding conditions,which were altered using different types of grinding media:iron,ceramic balls,and their mixture,followed by flotation in the cleaner *** flotation performance of rough Cu concentrate can be improved by changing the regrinding conditions based on the Py *** electron microscopy,X-ray spectrometry,ethylenediaminetetraacetic acid disodium salt extraction,and X-ray photoelectron spectroscopy studies illustrated that when the Py content was high,the use of iron media in regrinding promoted the generation of hydrophilic Fe OOH on the surface of Py and improved the Cu *** ceramic medium with a low Py content prevented excessive Fe OOH from covering the surface of chalcopyrite(Cpy).Electrochemical studies further showed that the galvanic corrosion current of Cpy-Py increased with the addition of Py and became stronger with the participation of iron media.

关键词： chalcopyrite regrinding media pyrite galvanic corrosion flotation

SEFormer:A Lightweight CNN-Transformer Based on Separable Multiscale Depthwise Convolution and Efficient Self-Attention for Rotating Machinery Fault Diagnosis

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Computers, Materials & Continua 2025年第1期82卷 1417-1437页

作者： Hongxing wang Xilai Ju Hua zhu Huafeng Li State Key Laboratory of Mechanics and Control for Aerospace Structures Nanjing University of Aeronautics and AstronauticsNanjing210016China School of Computer Science and Engineering Nanyang Technological UniversitySingapore639798Singapore

Traditional data-driven fault diagnosis methods depend on expert experience to manually extract effective fault features of signals,which has certain ***,deep learning techniques have gained prominence as a central focus of research in the field of fault diagnosis by strong fault feature extraction ability and end-to-end fault diagnosis ***,utilizing the respective advantages of convolution neural network(CNN)and Transformer in local and global feature extraction,research on cooperating the two have demonstrated promise in the field of fault ***,the cross-channel convolution mechanism in CNN and the self-attention calculations in Transformer contribute to excessive complexity in the cooperative *** complexity results in high computational costs and limited industrial *** tackle the above challenges,this paper proposes a lightweight CNN-Transformer named as SEFormer for rotating machinery fault ***,a separable multiscale depthwise convolution block is designed to extract and integrate multiscale feature information from different channel dimensions of vibration ***,an efficient self-attention block is developed to capture critical fine-grained features of the signal from a global ***,experimental results on the planetary gearbox dataset and themotor roller bearing dataset prove that the proposed framework can balance the advantages of robustness,generalization and lightweight compared to recent state-of-the-art fault diagnosis models based on CNN and *** study presents a feasible strategy for developing a lightweight rotating machinery fault diagnosis framework aimed at economical deployment.

关键词： CNN-Transformer separable multiscale depthwise convolution efficient self-attention fault diagnosis

Near-perfect replication on amorphous alloys through active force modulation based on machine learning/neural network parameter prediction

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 181-191页

作者： Senkuan Meng Zheng wang Ruisong zhu Ruijie Liu Jiang Ma Lina Hu Weihua wang Key Laboratory for Liquid-Solid Structural Evolution and Processing of Materials (Ministry of Education) School of Materials Science and Engineering Shandong University College of Mechatronics and Control Engineering Shenzhen University Songshan Lake Materials Laboratory Institute of Physics Chinese Academy of Sciences

As a microforming technique, micro/nano-structural replication possesses advantages of high precision and efficiency. With the remarkable superplasticity in the supercooled liquid region, amorphous alloys or metallic glasses(MGs) are regarded as ideal materials for miniature fabrication. However, due to the intrinsic metastable nature of supercooled liquids, the design of imprinting processes for MGs poses a challenge. In the past, process parameters have largely relied on trial-and-error *** this work, a low-frequency active force modulation system is employed to apply a stable, precise, and real-time feedback stress field for imprinting of MG samples. Low-frequency vibrations can facilitate the filling of microstructures on the template surface by reducing the effective viscosity of the supercooled liquid. With the dataset composed of orthogonal experiments, a machine learning strategy based on back-propagation(BP) neural networks was utilized to construct a 3D parameter space for temperature, stress, and time, and to predict the corresponding filling ratio. Furthermore, the optimal combination of imprinting process parameters was identified, and its filling ratio was experimentally validated to reach as high as 0.94. The near-perfect replication of microstructures confirms the superiority of the active force modulation system and the data-driven strategy of machine learning-assisted parameter design. At the same time, this one-step microforming process provides a new approach to addressing the accuracy-cost trade-off dilemma in precision manufacturing.

关键词： metallic glass amorphous alloy microforming imprinting machine learning

Netrin-1 signaling pathway mechanisms in neurodegenerative diseases

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Neural Regeneration Research 2025年第4期20卷 960-972页

作者： Kedong zhu Hualong wang Keqiang Ye Guiqin Chen Zhaohui Zhang Department of Neurology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina Department of Neurology The First Hospital of Hebei Medical UniversityBrain Aging and Cognitive Neuroscience Laboratory of Heibei ProvinceShijiazhuangHebei ProvinceChina Faculty of Life and Health Sciences Shenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhenGuangdong ProvinceChina

Netrin-1 and its receptors play crucial roles in inducing axonal growth and neuronal migration during neuronal *** profound impacts then extend into adulthood to encompass the maintenance of neuronal survival and synaptic *** amounts of evidence highlight several key points:(1)Diminished Netrin-1 levels exacerbate pathological progression in animal models of Alzheimer’s disease and Parkinson’s disease,and potentially,similar alterations occur in humans.(2)Genetic mutations of Netrin-1 receptors increase an individuals’susceptibility to neurodegenerative disorders.(3)Therapeutic approaches targeting Netrin-1 and its receptors offer the benefits of enhancing memory and motor function.(4)Netrin-1 and its receptors show genetic and epigenetic alterations in a variety of *** findings provide compelling evidence that Netrin-1 and its receptors are crucial targets in neurodegenerative *** a comprehensive review of Netrin-1 signaling pathways,our objective is to uncover potential therapeutic avenues for neurodegenerative disorders.

关键词： Alzheimer’s disease axon guidance colorectal cancer Netrin-1 receptors Netrin-1 signaling pathways Netrin-1 neurodegenerative diseases neuron survival Parkinson’s disease UNC5C

Software-defined process-near-memory architecture using 3D hybrid bonding integration

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Science China(Information Sciences) 2025年第1期68卷 366-378页

作者： Anlin XU Chenchen DENG Jianfeng zhu Yao wang Shaojun WEI Leibo LIU School of Integrated Circuits Tsinghua University Beijing Institution of Tracking and Communication Technology Beijing National Research Center for Information Science and Technology Tsinghua University

With the unprecedented explosive growing amount of global data, the development of computing chips, which encounter bottlenecks such as power wall and memory wall, cannot satisfy the demanding requirement. This work proposes a software-defined process-near-memory(SDPNM) computing architecture implemented using 3D hybrid bonding *** software-defined chip architecture, featuring spatial computations and dynamic reconfiguration, innovates in a top-down manner to achieve high energy efficiency while maintaining flexibility after fabrication. The process-near-memory integration further advances the SDNPM chip in a bottom-up way to reduce the energy consumption of data movement while improving the bandwidth. Utilizing a relatively mature fabrication and bonding process can result in feasible solutions for both data-intensive and compute-intensive applications including digital signal processing and artificial intelligence. The logic die is fabricated in the SMIC 40 nm process and the DRAM die is fabricated in the PSMC 25 nm process. The hybrid bonding is implemented by XMC. The experimental results show that the energy efficiency of the proposed SDPNM chip is 33.1× better than the state-of-the-art FPGA ranging from 8.2× to 104.1×.

关键词： software-defined chips process near memory energy efficiency dynamic reconfiguration domain specific

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