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Local-contrastive-learning machine with both generalization and adversarial robustness: A statistical physics analysis

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Science China(Physics,Mechanics & Astronomy) 2025年第1期Mechanics & Astronomy) .卷 109-123页

作者： Mingshan xie Yuchen Wang Haiping Huang PMI Lab School of Physics Sun Yat-sen University Guangdong Provincial Key Laboratory of Magnetoelectric Physics and Devices Sun Yat-sen University

Distinct from human cognitive processing, deep neural networks trained by backpropagation can be easily fooled by adversarial examples. To design a semantically meaningful representation learning, we discard backpropagation, and instead, propose a local contrastive learning, where the representations for the inputs bearing the same label shrink(akin to boson) in hidden layers,while those of different labels repel(akin to fermion). This layer-wise learning is local in nature, being biologically plausible.A statistical mechanics analysis shows that the target fermion-pair-distance is a key parameter. Moreover, the application of this local contrastive learning to MNIST benchmark dataset demonstrates that the adversarial vulnerability of standard perceptron can be greatly mitigated by tuning the target distance, i.e., controlling the geometric separation of prototype manifolds.

关键词： machine learning statistical mechanics adversarial robustness neural networks

Multi-layer multi-pass friction rolling additive manufacturing of Al alloy:Toward complex large-scale high-performance components

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 425-438页

作者： Haibin Liu Run Hou Chenghao Wu Ruishan xie Shujun Chen College of Mechanical&Energy Engineering Beijing University of TechnologyBeijing 100124China Chongqing Research Institute of Beijing University of Technology Chongqing 401121China

At present,the emerging solid-phase friction-based additive manufacturing technology,including friction rolling additive man-ufacturing(FRAM),can only manufacture simple single-pass *** this study,multi-layer multi-pass FRAM-deposited alumin-um alloy samples were successfully prepared using a non-shoulder tool *** material flow behavior and microstructure of the over-lapped zone between adjacent layers and passes during multi-layer multi-pass FRAM deposition were studied using the hybrid 6061 and 5052 aluminum *** results showed that a mechanical interlocking structure was formed between the adjacent layers and the adja-cent passes in the overlapped center *** friction and rolling of the tool head led to different degrees of lateral flow and plastic deformation of the materials in the overlapped zone,which made the recrystallization degree in the left and right edge zones of the over-lapped zone the highest,followed by the overlapped center zone and the non-overlapped *** tensile strength of the overlapped zone exceeded 90%of that of the single-pass deposition *** is proved that although there are uneven grooves on the surface of the over-lapping area during multi-layer and multi-pass deposition,they can be filled by the flow of materials during the deposition of the next lay-er,thus ensuring the dense microstructure and excellent mechanical properties of the overlapping *** multi-layer multi-pass FRAM deposition overcomes the limitation of deposition width and lays the foundation for the future deposition of large-scale high-performance components.

关键词： aluminum alloy additive manufacturing solid-state friction stir welding multi-layer multi-pass

Superhydrophobic and corrosion-resistant siloxane-modified MgAl-LDHs coatings on magnesium alloy prepared under mild conditions

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 450-463页

作者： Wenxi Zhang Zhangzelong Zhuo Dan Xu Liang Wu Zhihui xie Chemical Synthesis and Pollution Control Key Laboratory of Sichuan Province College of Chemistry and Chemical EngineeringChina West Normal UniversityNanchong 637002China College of Materials Science and Engineering/National Engineering Research Center for Magnesium Alloys Chongqing UniversityChongqing 400044China

We have developed a superhydrophobic and corrosion-resistant LDH-W/PFDTMS composite coating on the surface of Mg *** composite comprised a tungstate-intercalated(LDH-W)underlayer that was grown at low temperature(relative to hydrothermal reaction conditions)under atmospheric pressure and an outer polysiloxane layer created from a solution containing perfluorodecyltrimethoxysilane(PFDTMS)using a simple immersion *** successful intercalation of tungstate into the LDH phase and the following formation of the polysiloxane layer were confirmed through X-ray diffraction(XRD),Fourier transform infrared(FTIR)spectroscopy,and X-ray photoelectron spectroscopy(XPS).The corrosion resistance of the LDH-W film,both before and after the PFDTMS modification,was evaluated using electrochemical impedance spectroscopy(EIS),Tafel curves,and immersion *** results showed that Mg coated with LDH-W/PFDTMS exhibited significantly enhanced corrosion protection compared to the unmodified LDHW film,with no apparent signs of corrosion after exposure to 3.5wt%NaCl solution for 15 ***,the LDH-W/PFDTMS coating demonstrated superior superhydrophobicity and self-cleaning properties against water and several common beverages,as confirmed by static contact angle and water-repellency *** results offer valuable insights into preparing superhydrophobic and corrosion-resistant LDH-based composite coatings on Mg alloy surfaces under relatively mild reaction conditions.

关键词： Mg alloy corrosion coating layered double hydroxide

Bioinspired Ultrasensitive Flexible Strain Sensors for Real-Time Wireless Detection of Liquid leakage

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NANO-MICRO leTTERS 2025年第1期17卷 1-18页

作者： Zhou, Weilong Du, Yu Chen, Yingying Zhang, Congyuan Ning, Xiaowei xie, Heng Wu, Ting Hu, Jinlian Qu, Jinping Huazhong Univ Sci & Technol Sch Chem & Chem Engn Key Lab Mat Chem Energy Convers & Storage Minist EducHubei Key Lab Mat Chem & Serv Failure Wuhan 430074 Peoples R China Huazhong Univ Sci & Technol Hubei Engn Res Ctr Biomat & Med Protect Mat Sch Chem & Chem Engn Wuhan 430074 Peoples R China Wuhan Inst Technol Sch Mat Sci & Engn Wuhan 430205 Peoples R China City Univ Hong Kong Dept Biomed Engn Hong Kong 999077 Peoples R China

Micro-extrusion compression molding and surface modification were proposed for the mass fabrication of a superhydrophobic thermoplastic polyurethane sensor (TCGS).Inspired by scorpions, TCGS features Archimedean spiral crack arrays and micropores, achieving 218.13 sensitivity at 2% strain, a 4300% increase, and over 5000 usage cycles of *** robust superhydrophobicity of TCGS improves sensitivity and stability for detecting small-scale liquid leakage, allowing precise monitoring across various sizes and compositions while providing early warnings in various scenarios. Liquid leakage of pipeline networks not only results in considerable resource wastage but also leads to environmental pollution and ecological imbalance. In response to this global issue, a bioinspired superhydrophobic thermoplastic polyurethane/carbon nanotubes/graphene nanosheets flexible strain sensor (TCGS) has been developed using a combination of micro-extrusion compression molding and surface modification for real-time wireless detection of liquid leakage. The TCGS utilizes the synergistic effects of Archimedean spiral crack arrays and micropores, which are inspired by the remarkable sensory capabilities of scorpions. This design achieves a sensitivity of 218.13 at a strain of 2%, which is an increase of 4300%. Additionally, it demonstrates exceptional durability by withstanding over 5000 usage cycles. The robust superhydrophobicity of the TCGS significantly enhances sensitivity and stability in detecting small-scale liquid leakage, enabling precise monitoring of liquid leakage across a wide range of sizes, velocities, and compositions while issuing prompt alerts. This provides critical early warnings for both industrial pipelines and potential liquid leakage scenarios in everyday life. The development and utilization of bioinspired ultrasensitive flexible strain sensors offer an innovative and effective solution for the early wireless detection of liquid leakage.

关键词： Thermoplastic polyurethane Bioinspired Cracks Liquid leakage Flexible strain sensor

FK506 contributes to peripheral nerve regeneration by inhibiting neuroinflammatory responses and promoting neuron survival

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Neural Regeneration Research 2025年第7期20卷 2108-2115页

作者： Yuhui Kou Zongxue Jin Yusong Yuan Bo Ma Wenyong xie Na Han Department of Trauma and Orthopedics Peking University People’s HospitalBeijingChina National Center for Trauma Medicine Peking University People’s HospitalBeijingChina Key Laboratory of Trauma and Neural Regeneration(Peking University) Ministry of EducationBeijingChina Trauma Medicine Center Peking University People’s HospitalBeijingChina Department of Orthopedics China-Japan Friendship HospitalBeijingChina

FK506(Tacrolimus)is a systemic immunosuppressant approved by the *** and Drug ***506 has been shown to promote peripheral nerve regeneration,however,its precise mechanism of action and its pathways remain *** this study,we established a rat model of sciatic nerve injury and found that FK506 improved the morphology of the injured sciatic nerve,increased the numbers of motor and sensory neurons,reduced inflammatory responses,markedly improved the conduction function of the injured nerve,and promoted motor function *** findings suggest that FK506 promotes peripheral nerve structure recovery and functional regeneration by reducing the intensity of inflammation after neuronal injury and increasing the number of surviving neurons.

关键词： FK506 inflammation motor neurons nerve regeneration neuron peripheral nerve injury sensory neurons

Vertical handoff algorithm in heterogeneous networks to maximize system benefit

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Journal of Systems Engineering and Electronics 2009年第5期20卷 1124-1131页

作者： xie Shengdong Wu meng Computer and Software Inst. Nanjing Univ. of Information Science and Technology Nanjing 210044 P. R. China Communication and Information Engineering Inst. Nanjing Univ. of Posts and Telecommunications Nanjing 210003 P. R. China

A new vertical handoff decision algorithm is proposed to maximize the system benefit in heterogeneous wireless networks which comprise cellular networks and wireless local area networks （WLANs）. Firstly the block probability, the drop probability and the number of users in the heterogeneous networks are calculated in the channel-guard call admission method, and a function of the system benefit which is based on the new call arrival rate and the handoff call arrival rate is proposed. Then the optimal radius of WLAN is obtained by using simulation annealing （SA） method to maximize the benefit. All the nodes should handoff from cellular network to WLAN if they enter WLAN＇s scope and handoff from WLAN to cellular network if they leave the scope. Finally, the algorithm in different new call arrival rates and handoff call arrival rates is analyzed and results show that it can achieve good effects.

关键词： heterogeneous wireless networks vertical handoff system benefit simulated annealing optimization.

双轴应变对NbSe_(2)/MoSi_(2)N_(4)肖特基势垒的调控

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原子与分子物理学报 2025年第5期42卷 182-188页

作者：张宇哲安梦雅谢泉贵州大学大数据与信息工程学院新型光电子材料与技术研究所贵阳550025

最近一种高质量的二维(Two-dimensional,2D)半导体材料MoSi_(2)N_(4)(MSN)在实验上被成功合成,具有优异的电气和机械性能.尽管最近有大量的研究致力于揭示MSN的材料特性,但到目前为止,对MSN的电接触物理特性的探索还比较少.在这项工作中... 详细信息

最近一种高质量的二维(Two-dimensional,2D)半导体材料MoSi_(2)N_(4)(MSN)在实验上被成功合成,具有优异的电气和机械性能.尽管最近有大量的研究致力于揭示MSN的材料特性,但到目前为止,对MSN的电接触物理特性的探索还比较少.在这项工作中,构建了金属-半导体NbSe_(2)/MSN肖特基结并使用第一性原理密度泛函理论计算研究了该肖特基结的材料特性.发现NbSe_(2)/MSN接触具有超低肖特基势垒高度(Schottky barrier height,SBH),这有利于纳米电子学应用.SBH可以通过施加双轴应变的方式进行有效的调控.当施加拉伸应变时能实现NbSe_(2)/MSN肖特基结由p型肖特基接触转变为p型欧姆接触,而当施加较大的压缩应变时能实现p型肖特基接触和n型肖特基接触之间的转换.我们的研究结果为MSN的2D电触点的物理特性提供了见解,并将为设计基于MSN的2D纳米器件的高性能电触点提供关键的一步.

关键词： MoSi_(2)N_(4) NbSe_(2) 肖特基结欧姆接触

Visible-light-responsive homologous heterostructure of oxynitrides constructed to boost charge separation and water splitting

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Science China Chemistry 2025年第01期 186-191页

作者： Hai Zou Yunfeng Bao Xueshang Xin Yu Qi Tengfeng xie Fuxiang Zhang State Key Laboratory of Catalysis Dalian National Laboratory for Clean Energy Dalian Institute of Chemical Physics Chinese Academy of Sciences School of Chemistry and Chemical Engineering Liaoning Normal University College of Chemistry Jilin University

Constructing type II heterostructures represents a widely recognized strategy for enhancing charge separation and photocatalytic efficiency,but it remains challenging to fabricate homologous heterostructures based on visible-light-responsive semiconductors,especially for popularly investigated （oxy）nitrides with low thermal ***,we synthesized a homologous heterostructure （denoted as YTON＿H） based on the oxynitrides of YTaO4-xNyand YTa *** heterostructure exhibits type II band structure alignment and intimate interface achieved through a magnesium （Mg） powder-assisted nitridation *** with widely reported heterologous heterostructures,the as-obtained YTON＿H homologous heterostructure could similarly exhibit enhanced charge separation as well as photocatalytic water splitting performance with respect to its counterparts(YTaO4-xNyand YTaON2).Meanwhile,detailed structural characterizations and spectroscopy analysis have been made to confirm the formation of heterostructure and promotion of spatial charge separation.

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Unraveling the significance of cobalt on transformation kinetics,crystallography and impact toughness in high-strength steels

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 380-390页

作者： Yishuang Yu Jingxiao Zhao Xuelin Wang Hui Guo Zhenjia xie Chengjia Shang Collaborative Innovation Center of Steel Technology University of Science and Technology BeijingBeijing 100083China School of Materials Science and Engineering Shanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing 100083China

This work reveals the significant effects of cobalt(Co)on the microstructure and impact toughness of as-quenched highstrength steels by experimental characterizations and thermo-kinetic *** results show that the Co-bearing steel exhibits finer blocks and a lower ductile-brittle transition temperature than the steel without ***,the Co-bearing steel reveals higher transformation rates at the intermediate stage with bainite volume fraction ranging from around 0.1 to *** improved impact toughness of the Co-bearing steel results from the higher dense block boundaries dominated by the V1/V2 variant ***,the addition of Co induces a larger transformation driving force and a lower bainite start temperature(BS),thereby contributing to the refinement of blocks and the increase of the V1/V2 variant *** findings would be instructive for the composition,microstructure design,and property optimization of high-strength steels.

关键词： high-strength steel cobalt transformation kinetics crystallography impact toughness