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Emergent antisymmetric wrinkling patterns in films on ridged substrates

science China(Physics,Mechanics & Astronomy) 2023年第11期66卷 179-187页

作者： Jiahui Zhang Yi Sun Linghui He Yong Ni CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Modern MechanicsCAS Center for Excellence in Complex System MechanicsUniversity of Science and Technology of ChinaHefei230026China

We report the formation of antisymmetric wrinkling patterns in films on ridged substrates induced by the buckling instability of the substrates via finite element simulations and *** simulated results reveal that the uniaxial compression along the ridge can trigger both the wrinkling instability of the film and the lateral buckling instability of the *** latter could change the wrinkles from a symmetric pattern to an antisymmetric pattern in a range of film-substrate modulus ratio and aspect ratio of the ridge profile,as validated by the experimental observations.A three-dimensional phase diagram with four buckling patterns,i.e.,sole ridge buckling pattern,antisymmetric wrinkling pattern with different wavelengths from ridge buckling,symmetric wrinkling pattern without ridge buckling,and antisymmetric wrinkling pattern with the same wavelength as ridge buckling,is built with respect to the uniaxial compression,modulus ratio,and aspect *** results not only elucidate how and when the interplay between the wrinkling instability and the ridge instability results in the formation of the antisymmetric wrinkling pattern but also offer a way to generate controllable complex wrinkling patterns.

关键词： wrinkling pattern buckling instability ridged film-substrate system antisymmetric wrinkles

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Hierarchical palladium catalyst for highly active and stable water oxidation in acidic media

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National science Review 2023年第2期10卷 157-164页

作者： Jing Peng Haofeng Sun Kun Ni Jiajing Wu Xinyu Sun Yueqi Su Han Cheng Yuhua Liu Yuqiao Guo Wentuan Bi Yanwu Zhu Changzheng Wu Yi Xie Hefei National Laboratory for Physical Science at the Microscale CAS Center for Excellence in NanoscienceiChEM (Collaborative Innovation Center of Chemistry for Energy Materials) and CAS Key Laboratory of Mechanical Behavior and Design of Materials University of Science and Technology of China Institute of Energy Hefei Comprehensive National Science Center

Acidic water electrolysis is of great importance for boosting the development of renewable ***,it severely suffers from the trade-off between high activity and long lifespan for oxygen evolution catalysts on the anode *** is because the sluggish kinetics of oxygen evolution reaction necessitates the application of a high overpotential to achieve considerable current,which inevitably drives the catalysts far away from their thermodynamic equilibrium *** we demonstrate a new oxygen evolution model catalyst-hierarchical palladium（Pd） whose performance even surpasses the benchmark Ir-and Ru-based *** Pd catalyst displays an ultralow overpotential（196 mV）,excellent durability and mitigated degradation(66 μV h-1) at 10 mA cm-2in 1 M *** strain on Pd（111） facets weakens the binding of oxygen species on electrochemical etching-derived hierarchical Pd and thereby leads to two orders of magnitudes of enhancement of mass activity in comparison to the parent Pd bulk ***,the Pd catalyst displays the bifunctional catalytic properties for both oxygen and hydrogen evolutions and can deliver a current density of 2 A cm-2at a low cell voltage of 1.771 V when fabricated into polymer ele ctrolyte membrane ele ctrolyser.

关键词： palladium oxygen evolution reaction acidic condition strain electrolysis

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Self-healable gels in electrochemical energy storage devices

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Nano Research 2024年第4期17卷 3302-3323页

作者： Yang Li PeiPei Ding Yuzhe Gu Sheng Qian Yuncong Pang Lele Wang Jiayang Feng Baoguang Liu Qi Wan Ping Li Zhiwei Liu College of Electronic and Optical Engineering&College of Flexible Electronics(Future Technology) Nanjing University of Posts&Telecommunications(NJUPT)Nanjing 210023China State Key Laboratory of Organic Electronics and Information Displays&Jiangsu Key Laboratory for Biosensors Institute of Advanced Materials(IAM)Nanjing University of Posts and Telecommunications(NJUPT)Nanjing 210023China College of Materials Science&Engineering Beijing University of TechnologyBeijing 100124China Beijing Advanced Innovation Center for Materials Genome Engineering Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China Pillar of Engineering Product Development Singapore University of Technology and DesignSingapore 487372Singapore School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083China

In the green energy and carbon-neutral technology,electrochemical energy storage devices have received continuously increasing attention ***,due to the unavoidable volume expansion/shrinkage of key materials or irreversible mechanical damages during application,the stability of energy storage and delivery as well as the lifetime of these devices are severely shortened,leading to serious performance degradation or even safety ***,the utilization of self-healable gels into electrochemical energy storage devices,such as electrodes,binders,and electrolytes,is proven as an effective method to realize long-term stable operation of these devices via the self-repairing of mechanical and electrochemical ***,this review first summarizes the feature and fabrication of different gels,paying special attention to hydrogels,organohydrogels,and ***,basic concepts and figure of merit of self-healable gels are analyzed with a detailed discussion at the healing mechanisms,from reversible dynamic bonds to physical molecular diffusion,and to external healing *** we introduce all the important parts of electrochemical energy storage devices,which could be replaced by healable gels to enhance the durability,including electrodes,binders,and ***,the critical challenges and future perspectives regarding the future development of healable gels based high-performance electrochemical energy storage devices or electronics are provided.

关键词： self-healable gels healing mechanisms electrodes binders gel electrolytes

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Synthesis Optimization of SSZ-13 Zeolite Membranes by Dual Templates for N_(2)/NO_(2) Separation

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Chemical Research in Chinese Universities 2022年第1期38卷 250-256页

作者： LI Jun RONG Huazhen CHEN Cong LI Ziyi ZUO Jiayu WANG Wenjian LIU Xinjian GUAN Yixing YANG Xiong LIU Yingshu ZOU Xiaoqin ZHU Guangshan School of Energy and Environmental Engineering University of Science and Technology BeijingBeijing 100083P.R.China Faculty of Chemistry Northeast Normal UniversityChangchun 130024P.R.China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaChengdu 610213P.R.China

High-silica SSZ-13 zeolite membranes are promising in industrial separations of light gases and continuous membranes are highly demanded for better separation performances. Herein, pure-phase, continuous and thin SSZ-13 zeolite membranes were synthesized using dual templates of N,N,N-trimethtyl-1-adamantammonium hydroxide(TMAdaOH) and tetraethylammonium hydroxide(TEAOH). Systematical investigations of TMAdaOH/TEAOH ratios and their concentrations show that TMAdaOH acts as the main structure-directing agent in the formation of the SSZ-13 zeolite. TMAdaOH cooperatively plays with TEAOH in promoting the SSZ-13 crystal intergrowth to form a continuous polycrystalline membrane. Additionally, appropriate introduction of TEAOH is able to adjust the membrane thickness to the crystal-comparable size of ca. 2.0 μm. The SSZ-13 membranes are further applied for N2/NO2separation, which is firstly reported on zeolite membranes. The gas permeation results show that the SSZ-13 membrane synthesized by the dual-template approach exhibits selective separation of N2 over NO2 with N2/NO2 separation factor of 7.6 and N2 permeance of 1.66×10-8 mol·m-2·s-1·Pa-1.

关键词： Zeolite membrane Dual template SSZ-13 Gas separation Nitrogen dioxide

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Future Healthcare Recommender Systems: Applications, Open Issues, and Challenges

Future Healthcare Recommender Systems: Applications, Open Is...

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2024 IEEE International Conference on E-Health Networking, Application and Services, HealthCom 2024

作者： Ju, Hongzheng Jin, Kebing Tang, Jianhang Zhang, Yang Wang, Bo Xiong, Zehui State Key Laboratory of Public Big Data Guizhou University China College of Computer Science and Technology Nanjing University of Aeronautics and Astronautics China Pillar of Information Systems Technology and Design Singapore University of Technology and Design Singapore

ISBN: (纸本)9798350350548

With the enhancement of health awareness and the development of artificial intelligent technology, healthcare recommender systems (HRS) play an increasingly important role in individual health management. Meanwhile, the widespread usage of large models has significantly improved the efficiency and accuracy in the analysis and utilization of medical data. In this paper, we comprehensively summarize the basic types of recommender systems as well as the new trends in utilizing large models. Then we introduce the recommendation applications in healthcare areas from six aspects, i.e., disease risk prediction, medication recommendation, medical resource recommendation, mental health support, health life management, and health education. At last, we explore some current issues and challenges within HRS, as well as the development of potential solutions and directions in the future. © 2024 IEEE.

关键词： Electronic health record

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Finite Element Simulation of Radial Tire Building and Shaping Processes Using an Elasto-Viscoplastic Model

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Computer Modeling in Engineering & sciences 2023年第5期135卷 1187-1208页

作者： Yinlong Wang Zhao Li Ziran Li Yang Wang Department of Modern Mechanics CAS Key Laboratory of Mechanical Behavior and Design of MaterialsUniversity of Science and Technology of ChinaHefei230027China Wuhan Second Ship Design and Research Institute Wuhan430064China

The comprehensive tire building and shaping processes are investigated through the finite element method(FEM)in this *** mechanical properties of the uncured rubber from different tire components are investigated through cyclic loading-unloading experiments under different strain *** on the experiments,an elastoviscoplastic constitutive model is adopted to describe themechanical behaviors of the uncured *** distinct mechanical properties,including the stress level,hysteresis and residual strain,of the uncured rubber can all be well *** whole tire building process(including component winding,rubber bladder inflation,component stitching and carcass band folding-back)and the shaping process are simulated using this constitutive *** simulated green tire profile is in good agreement with the actual profile obtained through 3D *** deformation and stress of the rubber components and the cord reinforcements during production can be obtained fromthe FE simulation,which is helpful for judging the rationality of the tire construction ***,the influence of the parameter“drum width”is investigated,and the simulated result is found to be consistent with the experimental observations,which verifies the effectiveness of the *** established simulation strategy provides some guiding significance for the improvement of tire design parameters and the elimination of tire production defects.

关键词： Uncured rubber constitutive modeling radial tire building process finite element method

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Effect of Different Laser Energy Nitriding on the Fretting Wear Performance of Zr Alloy

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摩擦学学报（中英文） 2024年第9期44卷 1306-1321页

作者： NING Chuangming TANG Guocan YU Shijia ZHOU Junbo REN Quanyao ZENG Bing CAI Zhenbing Key Laboratory of Advanced Technologies of Materials Tribology Research InstituteSouthwest Jiaotong UniversitySichuan Chengdu 610031China School of Mechanical and Electrical Engineering Chengdu University of TechnologySichuan Chengdu 610031China Science and Technology on Reactor System Design Technology Laboratory Nuclear Power Institute of ChinaSichuan Chengdu 610213China

The zirconium(Zr)alloy fuel cladding is one of the key structural components of a nuclear reactor and the first and most important line of defense for accommodating fission *** the operation of nuclear reactors,Zr alloy fuel cladding is subjected to extreme harsh environments,such as high temperature,high pressure and high flow rate for a long period of *** wear and corrosion resistance of Zr alloys is important for the safe operation of nuclear *** modification can effectively improve the corrosion and wear resistance of fuel *** with coating technology,nitriding technology does not have problems for bonding between the coating and the *** research on surface nitriding of Zr alloys mainly focuses on plasma nitriding and ion implantation *** on laser nitriding of Zr alloy surfaces and their fretting wear characteristics is *** this study,the surface of Zr alloy was treated with laser nitriding at different laser *** microstructure of Zr alloy treated with different laser energies and its fretting wear performance were *** results showed that after nitriding with different laser energies,the surface of the Zr alloy showed a typical molten state after melting,vaporizing and cooling under the thermal effect of the laser,and this state was more obvious with the increase of the laser *** the same time,doping of N atoms and formation of the ZrN phase led to different cooling rates in the molten zone that produced large tensile stresses after *** led to cracks on the surface of Zr alloys after laser nitriding at different energies,and the crack density increased with increasing laser *** also led to an increase in the surface roughness of the Zr alloy with increasing laser energy after laser nitriding *** to the presence of water in the industrial nitrogen,nitrides were generated on the surface of the sample along with some *** the laser

关键词： zirconium alloy fretting wear laser nitriding delamination laser energy

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Ultrafine-grained LaB_(6)–ZrB_(2) composite ceramics with superior mechanical and thermionic emission properties prepared by highpressure sintering

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Journal of Advanced Ceramics 2024年第12期13卷 2021-2029页

作者： Xiaogang Guo An Liu Lingjuan Hao Hang Zhou Shuai Chen Pan Ying Bing Liu Baozhong Li Yufei Gao Zhisheng Zhao Ling Kong Mengdong Ma Xinyu Yang Dongli Yu Center for High Pressure Science(CHiPS) State Key Laboratory of Metastable Materials Science and TechnologyYanshan UniversityQinhuangdao 066004China State Key Laboratory of Crane Technology Yanshan UniversityQinhuangdao 066004China Handan key Laboratory of Intelligent Awareness and Application Handan UniversityHandan 056001China National Key Laboratory of Advanced Casting Technologies MIIT Key Laboratory of Advanced Metallic and Intermetallic Materials TechnologyEngineering Research Center of Materials Behavior and DesignMinistry of EducationNanjing University of Science and TechnologyNanjing 210094China School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China School of Materials Science and Engineering Hefei University of TechnologyHefei 230009China

In this study,ultrafine-grained LaB_(6)–ZrB_(2)composite ceramics were successfully synthesized by sintering a mixture of self-produced LaB_(6)nanopowder and commercial ZrB_(2)nanopowder under high *** with their coarse-grained counterparts,ultrafine-grained ceramics exhibit improved mechanical ***,the ultrafinegrained LaB_(6)–ZrB_(2)composite ceramic sintered at 4 GPa and 1673 K,with an average grain size of 286 nm,shows optimal mechanical performance characterized by a Vickers hardness of 25.6 GPa,a fracture toughness of 4.1 MPa·m^(1/2),and an elastic modulus of 338 ***,the ultrafine-grained LaB_(6)–ZrB_(2)composite ceramics displayed strong thermal emission,reaching a maximum current density of 27.5 A∙cm^(−2)at 1773 *** structural and functional advantages of ultrafine-grained LaB_(6)–ZrB_(2)composite ceramics render them suitable for potential use in thermionic emission cathodes.

关键词： LaB_(6)-ZrB_(2) ultrafine-grained high pressure mechanical properties thermal field emission

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Comparison of Showerhead Film Cooling and Double Wall Cooling in a Guide Vane Leading Edge with Hot Streak

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International Journal of Gas Turbine, Propulsion and Power Systems 2024年第1期15卷 24-31页

作者： Chen, Jinfu He, Yang Yao, Ran Wang, Jianhua CAS Key Laboratory of Mechanical Behavior and Design of Materials Department of Thermal Science and Energy Engineering United States University of Science and Technology of China Jinzhai Road No. 96 Anhui Hefei230027 China

Under the realistic running conditions of gas turbines, the temperature at mainstream inlet is always non-uniform due to the effects of combustion process, and different types of hot streak (HS) could be found at the inlet. The existence of HS may result in some potential negative impacts on the cooling performances of vane leading edge (LE). Nowadays, the two configurations, i.e., traditional showerhead film cooling (SFC) and novel double wall cooling (DWC), have been widely used in LE designs of turbine vanes, but until now there is no comprehensive study to evaluate the two models considering HS effects. In this work, using the two cooling structures, four different temperature profiles are considered at the mainstream inlet of the cascade. The results reveal that: in both models, HS could cause a local high-temperature region on LE, and the thermal characteristics of this area are dependent on HS pattern. Compared to SFC, DWC shows a better cooling ability and a lower thermal stress on the vane surface. The cooling characteristics in DWC model are less sensitive to the HS pattern. However, the problem of the extremely high thermal stress within the pin-fins of DWC should be carefully considered. © 2024 Gas Turbine Society of Japan. All rights reserved.

关键词： Gas turbines

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Positive and Unlabeled Learning with Controlled Probability Boundary Fence 41

Positive and Unlabeled Learning with Controlled Probability ...

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41st International Conference on Machine Learning, ICML 2024

作者： Li, Changchun Dai, Yuanchao Feng, Lei Li, Ximing Wang, Bing Ouyang, Jihong College of Computer Science and Technology Jilin University China Key Laboratory of Symbolic Computation and Knowledge Engineering of Ministry of Education Jilin University China Information Systems Technology and Design Pillar Singapore University of Technology and Design Singapore

Positive and Unlabeled (PU) learning refers to a special case of binary classification, and technically, it aims to induce a binary classifier from a few labeled positive training instances and loads of unlabeled instances. In this paper, we derive a theorem indicating that the probability boundary of the asymmetric disambiguation-free expected risk of PU learning is controlled by its asymmetric penalty, and we further empirically evaluated this theorem. Inspired by the theorem and its empirical evaluations, we propose an easy-to-implement two-stage PU learning method, namely Positive and Unlabeled Learning with Controlled Probability Boundary Fence (PUL-CPBF). In the first stage, we train a set of weak binary classifiers concerning different probability boundaries by minimizing the asymmetric disambiguation-free empirical risks with specific asymmetric penalty values. We can interpret these induced weak binary classifiers as a probability boundary fence. For each unlabeled instance, we can use the predictions to locate its class posterior probability and generate a stochastic label. In the second stage, we train a strong binary classifier over labeled positive training instances and all unlabeled instances with stochastic labels in a self-training manner. Extensive empirical results demonstrate that PUL-CPBF can achieve competitive performance compared with the existing PU learning baselines. Copyright 2024 by the author(s)

关键词： Contrastive Learning

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