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Clarifying the adverse effect of secondary phase on the tribological property of Mg alloy

Journal of Magnesium and Alloys 2025年

作者： Li, Jie Zou, Ting Yang, Junjie Yu, Helong Zhang, Peng Ji, Xiaochao Zhao, Xin Yan, Zhiyong Li, Wei Institute of Advanced Wear & Corrosion Resistant and Functional Materials Jinan University Guangzhou510632 China Shaoguan Research Institute of Jinan University Shaoguan512027 China National Key Laboratory for Remanufacturing of AAAF Beijing100072 China School of Mechatronic Engineering and Automation Foshan University Foshan528225 China Inner Mongolia First Machinery Group Co. LTD Baotou014030 China National Joint Engineering Research Center of High Performance Metal Wear Resistant Materials Technology Jinan University Guangzhou510632 China

Introduction of hard particles is considered an effective approach to improve alloy wear resistances. However, the wear resistances of Mg alloys could be deteriorated by increasing the hard particle content in many researches. To reveal the underlying negative effect of precipitate on the wear resistance, the wear behaviors of three AZ-Mg alloys (precipitate contents: AZ31: 2.1 %, AZ61: 3.8 %, AZ91: 5.0 %) at the axial loads of 3 and 15 N were investigated. The results indicated that although wear volume of the AZ-Mg alloys decreased with the increasing Mg17Al12 content at 3 N (0.30→0.24→0.20 µm3) and 15 N (1.04→0.88→0.85 µm3), the relative wear resistances of AZ61 and AZ91 to AZ31 decreased with increasing load (AZ61: 1.25→1.17, AZ91: 1.50→1.22) and the reduction was proportional to the precipitates content (AZ61:7 %, AZ91:28 %). That is because the wear volume of AZ-Mg was mainly attributed to micro-cutting, which was negatively correlated with the precipitate content and tribolayer hardness. However, the wear hardening ability of AZ-Mg alloys was weakened by precipitate for its inhibition on the formation of mechanical twins that the precursors for the tribolayer. Moreover, the inhibition of the precipitate on tribolayer could be amplified by the load, resulting in an increase in tribolayer hardness at 3 N (AZ31: 0.94, AZ61: 1.03, AZ91: 1.10 GPa) but a decrease at 15 N (AZ31: 1.77, AZ61: 1.73, AZ91: 1.62 GPa). Therefore, the formation of twin was inhibited by precipitates, which is detrimental to the wear resistance of Mg alloys. That means the wear resistance could be enhanced by promoting twin formation, which provides a new concept for the design of wear-resistant Mg alloys. © 2025

关键词： Magnesium alloys

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performance Optimization and Comparison of the Alternating Direction Implicit CFD Solver on Multi-core and Many-Core Architectures

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Chinese Journal of Electronics 2018年第3期27卷 540-548页

作者： DENG Liang ZHAO Dan BAI Hanli WANG Fang Computational Aerodynamics Institue China Aerodynamics Research and Development Center Collaborative Innovation Center of High Performance Computing National University of Denfense Technology School of Computer National University of Denfense Technology

We accelerate a double precision Alternating direction implicit(ADI) solver for three-dimensional compressible Navier-Stokes equations from our in-house Computational fluid dynamics(CFD) software on the latest multi-core and many-core architectures(Intel Sandy Bridge CPUs, Intel Many integrated core(MIC) coprocessors and NVIDIA Kepler K20c GPUs). Some performance optimization techniques are detailed discussed. We provide an in-depth analysis on the performance difference between Sandy Bridge and MIC. Experimental results show that the proposed GPU-enabled ADI solver can achieve a speedup of 5.5 on a Kepler GPU in contrast to two Sandy Bridge CPUs and our optimization techniques can improve the performance of the ADI solver by 2.5-fold on two Sandy Bridge CPUs and 1.7-fold on an Intel MIC coprocessor. We perform a cross-platform performance analysis(between GPU and MIC), which serves as case studies for developers to select the right accelerators for their target applications.

关键词： Multi-block Structured grid Alternating direction implicit(ADI) CFD solver Sandy bridge MIC GPU Optimization techniques performance comparison

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Enhancing Oxygen Reduction Reaction in PdHx@Pt Metallenes: Unveiling the Impact of Ligand Beyond Strain Effect

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Advanced Functional Materials 2025年

作者： Feng, Zhipeng Jiao, Dongxu Fan, Jinchang Qiu, Yu Ge, Xin Wang, Jiaqi Zhao, Xiao Zhang, Wei Zheng, Lirong Zhang, Lei Yu, Zhigen Zheng, Weitao Cui, Xiaoqiang School of Materials Science and Engineering Key Laboratory of Automobile Materials Electron Microscopy Center Jilin University No.2699 Qianjin Street Changchun130012 China Beijing Synchrotron Radiation Facility Institute of High Energy Physics Chinese Academy of Sciences No.19 Yuquan Road Beijing100049 China College of Chemistry Jilin University No.2699 Qianjin Street Changchun130012 China Institute of High-Performance Computing Agency for Science Technology and Research No.1 Fusionopolis Way Singapore138632 Singapore

Incorporating interstitial non-metal atoms within the crystal lattice of catalysts enables flexible modulation of their electronic structures and catalytic performances. However, the resulting induced tensile strain typically has a detrimental effect on oxygen reduction reaction (ORR) activity. In this study, a series of PdHx@Pt metallenes with varying H/Pd ratios, where hydrogen atoms precisely modulate the strain and ligand effects on the Pt skin surface is reported. Notably, PdH0.35@Pt metallenes exhibit an extraordinary half-wave potential of 0.933 V and a mass activity (MA) of 7.36 A mgPt−1 at 0.9 V vs reversible hydrogen electrode (RHE) for ORR, outperforming both Pd@Pt metallenes and commercial Pt/C catalysts. Control experiments and density functional theory (DFT) calculations reveal a competitive relationship between strain and ligand effects across different H/Pd ratios, with a dominant positive ligand effect overcoming the negative strain effect at an H/Pd ratio of 0.35. This electronic structure modulation leads to an increased 5d electron density of the surface Pt and a downshift in the eg* band center, thereby weakening the adsorption of oxygen intermediates on the Pt skin surface and resulting in excellent ORR activity. © 2025 Wiley-VCH GmbH.

关键词： Ligands

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F2UE-NET: An Uncertainty-Driven Dynamic Expert Network for Long-Tail Retinal Disease Classification

F2UE-NET: An Uncertainty-Driven Dynamic Expert Network for L...

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IEEE International Symposium on Biomedical Imaging

作者： Junyong Zhao Tian Lin Meng Wang Liang Sun Haoyu Chen Daoqiang Zhang Huazhu Fu MOE Key Laboratory of Brain Computer Intelligence Technology College of Artificial Intelligence Nanjing University of Aeronautics and Astronautics Nanjing China Joint Shantou International Eye Center Shantou University and the Chinese University of Hong Kong Shantou Guangdong China Department of Ophthalmology Yong Loo Lin School of Medicine National University of Singapore Singapore Singapore Agency for Science Technology and Research (A*STAR) Institute of High Performance Computing (IHPC) Singapore Singapore

ISBN: (数字)9798331520526

ISBN: (纸本)9798331520533

The automatic diagnosis of retinal diseases presents a significant challenge in medical image analysis, primarily due to the long-tail distribution in existing retinal datasets. This imbalance creates substantial difficulties in model training and performance. To address this issue, we propose an uncertainty-driven dynamic expert network for long-tail retinal disease classification, called $\mathrm{F}^performance\text{UE}$ -Net. Specifically, we apply Low-Rank Adaptation (LoRA) technology to fine-tune the foundation model, enhancing its feature extraction capabilities and overall performance. Additionally, we introduce an uncertainty-driven dynamic expert participation strategy, which assigns appropriate weights to different categories during training, ensuring high accuracy even for rare, tail-end diseases. Experimental results on a long-tail fundus disease dataset demonstrate that $\mathrm{F}^performance$ UE outperforms state-of-the-art methods in long-tail retinal disease classification.

关键词： Training Heavily-tailed distribution Image analysis Foundation models Biological system modeling Tail Retina Feature extraction Medical diagnostic imaging Diseases

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Collective nature of high-Q resonances in finite-size photonic metastructures

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Physical Review research 2025年第1期7卷 013316-013316页

作者： Thanh Xuan Hoang Daniel Leykam Hong-Son Chu Ching Eng Png Francisco J. García-Vidal Yuri S. Kivshar Institute of High Performance Computing (IHPC) Agency for Science Technology and Research (ASTAR) 1 Fusionopolis Way #16-16 Connexis Singapore 138632 Republic of Singapore Science Mathematics and Technology Cluster Singapore University of Technology and Design 8 Somapah Road Singapore 487372 Republic of Singapore Departamento de Física Teórica de la Materia Condensada and Condensed Matter Physics Center (IFIMAC) Universidad Autónoma de Madrid E-28049 Madrid Spain Nonlinear Physics Centre Research School of Physics The Australian National University Canberra ACT 2601 Australia

We study high-quality factor (high Q) resonances in periodic and disordered arrays of Mie resonators from the perspectives of both Bloch wave theory and multiple scattering theory. We reveal that, unlike a common belief, the bound states in the continuum (BICs) derived by the Bloch-wave theory do not directly determine the resonance with the highest Q value in large but finite arrays. higher Q factors appear to be associated with collective resonances formed by nominally guided modes below the light line associated with strong-coupling effect of both electric and magnetic multipoles. Our findings offer valuable insights into accessing the modes with higher Q resonances via bonding modes within finite metastructures. Our results underpin the pivotal significance of magnetic and electric multipoles in the design of resonant metadevices and nonlocal flat-band optics. Moreover, our demonstrations reveal that coupled arrays of high-Q microcavities do not inherently result in a stronger light-matter interaction when compared to coupled low-Q nanoresonators. This result emphasizes the critical importance of multiple light-scattering effects in cavity-based systems.

关键词： Microcavities

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Influence of colloidal silica properties on chemical mechanical polishing of zirconia ceramics

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Ceramics International 2025年

作者： Lin, Wenkun Qi, Yongchi Zhang, Xueju Gu, Yunyun Wang, Yue Qian, Hongwei Luo, Hui Chen, Jiapeng Research Center for Advanced Micro-/Nano- Fabrication Materials School of Chemistry and Chemical Engineering Shanghai University of Engineering Science Shanghai201620 China School of Electro-Mechanical Engineering Zhongyuan Institute of Science and Technology Xuchang461000 China Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology National Key Laboratory of Science and Technology on Helicopter Transmission College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics Nanjing210016 China State Key Laboratory of Silicon and Advanced Semiconductor Materials Zhejiang University Hangzhou310027 China State Key Laboratory for High Performance Tools Zhengzhou Research Institute for Abrasives & Grinding Co. Ltd Henan 450001 China

Zirconia ceramics (ZrO2) have a wide range of applications in many fields due to their many advantages such as high hardness, corrosion resistance, high dielectric constant, no signal shielding, and excellent biocompatibility. Currently, colloidal silica (SiO2) is widely employed in the chemical mechanical polishing (CMP) of ZrO2 wafers in industrial applications. While extensive research has been conducted on the effects of colloidal silica's mechanical properties on ZrO2 polishing, relatively little attention has been given to the adsorption properties of the SiO2 surface. Furthermore, the influence of the acidity (Si-OH groups) and surface adsorption characteristics of ZrO2 on the CMP removal mechanism remains underexplored. Therefore, in this paper, three alkaline molecular probes are introduced to investigate the acidity and surface adsorption properties of colloidal silica, and the interfacial reaction and material removal mechanism of colloidal silica on ZrO2 polishing are characterized and analyzed by contact angle test, X-ray photoelectron spectroscopy (XPS) and low-field nuclear magnetic resonance (LF-NMR). The results show that there are two reaction mechanisms for chemical mechanical polishing material removal rate (MRR) of ZrO2. Under acidic polishing conditions, there is no significant correlation between MRR and the acidity of Si-OH groups on the surface of the colloidal silica, and MRR is closely related to the erosion of Zr-OH on the surface of ZrO2 by Si-OH groups, which undergoes a dehydration condensation reaction. However, under alkaline polishing conditions, deprotonated Si-O-groups play a dominant role in the polishing activity and are accompanied by the generation and removal of reaction products (zirconium silicates). The optimal polishing efficiency in an acidic polishing environment, particularly when zirconia reaches its isoelectric point at pH = 6, may be attributed to the enhanced chemical reactivity between the ZrO2 and SiO2 surfaces a

关键词： Corrosion resistance

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Effect mechanism of diamond content on tribo-chemical processing of sapphire wafers using developed clusters of diamond and ceria chemically agglomerated abrasive cluster

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Ceramics International 2025年

作者： Wang, Zhankui Huang, Shangci Liu, Kuncheng Zhao, Zhicheng Fan, Yihang Chen, Jiapeng Yao, Yunlong Pang, Minghua Ma, Lijie Su, Jianxiu School of Mechanical and Electrical Engineering Henan Institute of Science and Technology Henan Xinxiang453003 China School of Information Engineering Henan University of Science and Technology Henan Luoyang471000 China Research Center for Advanced Micro-/Nano- Fabrication Materials College of Chemistry and Chemical Engineering Shanghai University of Engineering Science Shanghai201620 China State Key Laboratory for High Performance Tools Zhengzhou Abrasive Grinding Research Institute Co. Ltd Henan 450001 China State Key Laboratory of Silicon and Advanced Semiconductor Materials Zhejiang University Hangzhou310027 China Jiangsu Key Laboratory of Precision and Micro-Manufacturing Technology National Key Laboratory of Science and Technology on Helicopter Transmission College of Mechanical and Electrical Engineering Nanjing University of Aeronautics and Astronautics Nanjing210016 China

To enhance the material removal rate (MRR) and surface quality of sapphire wafers during lapping, this study proposes a new method for preparing chemically agglomerated abrasive clusters (CAAC). Using this method, five distinct CAAC abrasives, each with a different diamond content, were prepared for lapping experiments on sapphire wafers. MRR and surface roughness Ra were used as evaluation indicators to elucidate the removal behavior of CAAC abrasive particles during the lapping of sapphire wafers. The study analyzed changes in the friction curve, the elemental composition of the sapphire surface before and after lapping, and the microscopic morphology of the CAAC abrasives. The results indicate that #4 CAAC demonstrates the highest MRR and favorable surface quality among the tested variants. Specifically, #4 CAAC achieved the highest removal rate of 380.267 nm/min and the lowest surface roughness of 33.978 nm, outperforming #1, #2, #3, and #5 CAAC. Compared to W50 single crystalline diamond (W50 SCD) of equivalent grain size, the MRR increased by a factor of 3.1. Furthermore, within a certain range, the machining performance of CAAC improves with an increase in diamond content;however, both excessively high and low diamond contents negatively impact overall performance. When the diamond content in CAAC reaches 42 %, machinability is optimized. This method enhances the processing efficiency of sapphire wafers, improves surface quality, and offers innovative approaches for efficient and cost-effective sapphire wafer processing. © 2025 Elsevier Ltd and Techna Group S.r.l.

关键词： Chemically agglomerated abrasives cluster Diamond Lapping Sapphire

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Pier scour monitoring system by bed-level image tracking

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International Journal of Sediment research 2014年第2期29卷 269-277页

作者： Wen-Yi CHANG Jihn-Sung LAI Teng-Yi YU Franco LIN Lung-Cheng LEE Whey-Fone TSAI Chin-Hsiung LOH National Center for High-Performance Computing National Applied Research Laboratories Research fellow Hydrotech Research InstituteNational Taiwan University Department of Civil Engineering National Taiwan University

A scour monitoring system with a micro camera tracking the bed-level images is proposed in this *** image recognition algorithms have been developed to support the bed-level image tracking *** the laboratory experiments of pier scour,this study demonstrates that the proposed system is able to accurately monitor the scour-depth evolution in real *** addition,five commonly-used temporal scour models are employed to simulate scour-depth evolution and their results are compared with monitoring *** general,the results indicate that the proposed scour monitoring system has the potential for further applications in the field.

关键词： Pier scour Scour monitoring Image recognition Bed-level image tracking Scour prediction

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3D printing for tissue/organ regeneration in China

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Bio-Design and Manufacturing 2025年第2期8卷 169-242,I0001,I0002页

作者： Chaofan He Jiankang He Chengtie Wu Changshun Ruan Qi Gu Yongqiang Hao Yang Wu Shuo Bai Xiaoxiao Han Liliang Ouyang Jun Yin Hongzhao Zhou Zhuo Xiong Maobin Xie Lei Shao Jing Nie Liang Ma Cijun Shuai Changchun Zhou Xin Zhao Xuetao Shi Mengfei Yu Jiayin Fu Peng Wen Huixia Xuan Yuan Pang Yan’en Wang Yuan Sun Ziqi Gao Abdellah Aazmi Jingbo Zhang Tianhong Qiao Qixiang Yang Ke Yao Mao Mao Jianxin Hao Pinpin Wang Jirong Yang Huawei Qu Xinhuan Wang Xin Liu Shen Ji Shasha Liu Jingke Fu Bingxian Lu Mohan Wu Feng Chen Zihao Zheng Boqing Zhang Muyuan Chai Chaoying Zhang Mouyuan Sun Bo Peng Huayong Yang Yong He State Key Laboratory of Fluid Power and Mechatronic Systems School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China Key Laboratory of 3D Printing Process and Equipment of Zhejiang Province School of Mechanical EngineeringZhejiang UniversityHangzhou 310027China State Key Laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710049China State Key Laboratory of High Performance Ceramics and Superfine Microstructure Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Research Center for Human Tissue and Organ Degeneration Institute of Biomedicine and BiotechnologyShenzhen Institutes of Advanced TechnologyChinese Academy of SciencesShenzhen 518055China University of Chinese Academy of Sciences Beijing 100049China Key Laboratory of Organ Regeneration and Reconstruction State Key Laboratory of Membrane BiologyInstitute of ZoologyChinese Academy of SciencesBeijing 100101China Beijing Institute for Stem Cell and Regenerative Medicine Beijing 100101China Shanghai Engineering Research Center of Innovative Orthopaedic Instruments and Personalized Medicine Clinical and Translational Research Center for 3D Printing TechnologyShanghai 200011China School of Biomedical Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China State Key Laboratory of Biochemical Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Key Laboratory of Biopharmaceutical Preparation and Delivery Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China National Engineering Research Centre for High Efficiency Grinding Hunan UniversityChangsha 410082China Biomanufacturing Center Department of Mechanical EngineeringTsinghua UniversityBeijing 100084China State Key Laboratory of Tribology in Advanced Equipment Tsinghua UniversityBeijing 100084China The Fourth Affiliated Hospital of Guangzhou Medical University Guangzhou 511436China School of Biomedical Engineering Guangzhou Medic

As surgical procedures transition from conventional resection to advanced tissue-regeneration technologies,human disease therapy has witnessed a great leap *** particular,three-dimensional(3D)bioprinting stands as a landmark in this setting,by promising the precise integration of biomaterials,cells,and bioactive molecules,thus opening up a novel avenue for tissue/organ *** by the editorial board of Bio-Design and Manufacturing,this review brings together a cohort of leading young scientists in China to dissect the core functionalities and evolutionary trajectory of 3D bioprinting,by elucidating the intricate challenges encountered in the manufacturing of transplantable *** further delve into the translational pathway from scientific research to clinical application,emphasizing the imperativeness of establishing a regulatory framework and rigorously enforcing quality-control ***,this review outlines the strategic landscape and innovative achievements of China in this field and provides a comprehensive roadmap for researchers worldwide to propel this field collectively to even greater heights.

关键词： 3D printing Bioprinting Tissue engineering Regenerative medicine

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A CONTROL ALGORITHM FOR RAPID MOVEMENTS NEAR THE RADIUS COMPENSATION SINGULARITY IN FIVE-AXIS END MILLING

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Journal of Systems Science & Complexity 2013年第5期26卷 718-734页

作者： WANG Feng LIN Hu ZHENG Liaomo LIU Feng YANG Lei GENG Cong Graduate University of Chinese Academy of Sciences National Engineering Research Center for High-End CNC Shenyang Institute of Computing TechnologyChinese Academy of Sciences National Engineering Research Center For High-End CNC Shenyang Institute of Computing TechnologyChinese Academy of Sciences University of Science and Technology of China

When the five-axis CNC system executes the 3D cutter radius compensation function,the angle between two adjacent radius compensation vectors might become very large and the linear axes would move too fast if the tool orientation vector is close to the surface *** reason that results in this phenomenon is analyzed based on building the transmission relationship between the cutter contact point and the cutter location *** taking the square-end tool as an example,an optimization algorithm to control the undesired movements is *** the singular area where sudden change exists,the number of interpolation cycles is determined by the cutter feedrate,the limit speeds of machine axes and the maximum allowable angle between radius compensation vectors of adjacent NC *** radius compensation vector of each interpolation cycle is obtained by a kind of vector rotation *** maintaining the perpendicularity between the radius compensation vector and the tool orientation vector,the rapid movements of the linear axes are eliminated.A trial-cut experiment is performed to verify the correctness and the effectiveness of the proposed algorithm.

关键词： Five-axis machining motion control singularity 3D radius compensation.

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