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Fourth-order phase-field modeling for brittle fracture in piezoelectric materials

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Applied Mathematics and Mechanics(English Edition) 2024年第5期45卷 837-856页

作者： Yu TAN Fan PENG chang LIU Daiming PENG Xiangyu LI State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu 610059China College of Science Chang'an UniversityXi'an 710064China Applied Mechanics and Structure Safety Key Laboratory of Sichuan Province School of Mechanics and Aerospace EngineeringSouthwest Jiaotong UniversityChengdu 610031China

Failure analyses of piezoelectric structures and devices are of engineering and scientific *** this paper,a fourth-order phase-field fracture model for piezoelectric solids is developed based on the Hamilton *** typical electric boundary conditions are involved in the present model to characterize the fracture behaviors in various physical situations.A staggered algorithm is used to simulate the crack *** polynomial splines over hierarchical T-meshes(PHT-splines)are adopted as the basis function,which owns the *** numerical simulations are performed to study the influence of the electric boundary conditions and the applied electric field on the fracture behaviors of piezoelectric *** electric boundary conditions may influence crack paths and fracture loads *** present research may be helpful for the reliability evaluation of the piezoelectric structure in the future applications.

关键词： isogeometric analysis(IGA) brittle fracture fourth-order phase-field model piezoelectric solid

Effect of bipolar-plates design on corrosion,mass and heat transfer in proton-exchange membrane fuel cells and water electrolyzers:A review

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International Journal of Minerals,Metallurgy and Materials 2024年第7期31卷 1599-1616页

作者： Jiuhong Zhang Xiejing Luo Yingyu Ding Luqi chang Chaofang Dong Key Laboratory for Corrosion and Protection(MOE) Institute for Advanced Materials and TechnologyUniversity of Science and Technology BeijingBeijing 100083China Beijing Advanced Innovation Center for Materials Genome Engineering Beijing 100083China

Attaining a decarbonized and sustainable energy system,which is the core solution to global energy issues,is accessible through the development of hydrogen ***-exchange membrane water electrolyzers(PEMWEs)are promising devices for hydrogen production,given their high efficiency,rapid responsiveness,and *** plates account for a relatively high percentage of the total cost and weight compared with other components of ***,optimization of their design may accelerate the promotion of *** paper reviews the advances in materials and flow-field design for bipolar ***,the working conditions of proton-exchange membrane fuel cells(PEMFCs)and PEMWEs are compared,including reaction direction,operating temperature,pressure,input/output,and ***,the current research status of bipolar-plate substrates and surface coatings is summarized,and some typical channel-rib flow fields and porous flow fields are ***,the effects of materials on mass and heat transfer and the possibility of reducing corrosion by improving the flow field structure are ***,this review discusses the potential directions of the development of bipolar-plate design,including material fabrication,flow-field geometry optimization using threedimensional printing,and surface-coating composition optimization based on computational materials science.

关键词： bipolar-plates flow design mass and heat transfer corrosion water electrolyzers fuel cells

An online value iteration method for linear-quadratic mean field social control with unknown dynamics

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Science China(Information Sciences) 2024年第4期67卷 38-39页

作者： Bing-chang WANG Shumei LI Ying CAO School of Control Science and Engineering Shandong University

Mean field(MF) models have been widely applied to economics, control theory, and other fields. Its prominent feature is that the individual influence on the overall population is negligible and the impact of the entire system to the single agent is significant and cannot be ignored. As a classical problem in control theory, linear quadratic(LQ) control for MF models has been widely investigated(e.g., [1, 2]).

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Copper coordination-driven self-assembly and encapsulation of PCR reagents

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Chinese Chemical Letters 2024年第3期35卷 189-192页

作者： chang Lu Jinkai Zheng Juewen Liu Institute of Food Science and Technology Chinese Academy of Agricultural SciencesBeijing 100193China Department of Chemistry Waterloo Institute for NanotechnologyUniversity of WaterlooWaterlooONN2L 3G1Canada

Polymerase chain reactions(PCR)are a very important tool for use in cloning,nucleic acid sequencing and diagnostic *** storage conditions of PCR reagents are limited to freezing and a lot of mixing steps are *** this paper,we report using metal ions to form coordination nanomaterials with the intrinsic components of the PCR reagents including dNTP,DNA primers and DNA polymerase as an integrated PCR reaction *** complete PCR reactions,users need only to dissolve the coordination nanomaterials with a buffer and add template DNA.A few transition metal ions were screened and Cu^(2+)was found to be the most effective metal ion for this *** the encapsulation efficiency of PCR reagents was measured,which can reach close to 100%for the primers and DNA polymerase,but only 10%for dNTP because dNTP was *** study also exhibited this integrated PCR reaction system can be used for DNA detection with a similar detection limit to the normal PCR,and showed good stability of encapsulated PCR nanomaterial after storage for a week.

关键词： Metal ions Coordination Encapsulation PCR Storage

Cell Consistency Evaluation Method Based on Multiple Unsupervised Learning Algorithms

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Big Data Mining and Analytics 2024年第1期7卷 42-54页

作者： Jiang chang Xianglong Gu Jieyun Wu Debu Zhang Stellantis China Technology Center Shanghai 200233China

Unsupervised learning algorithms can effectively solve sample *** address battery consistency anomalies in new energy vehicles,we adopt a variety of unsupervised learning algorithms to evaluate and predict the battery consistency of three vehicles using charging fragment data from actual operating *** extract battery-related features,such as the mean of maximum difference,standard deviation,and entropy of batteries and then apply principal component analysis to reduce the dimensionality and record the amount of preserved *** then build models through a collection of unsupervised learning algorithms for the anomaly detection of cell consistency *** also determine whether unsupervised and supervised learning algorithms can address the battery consistency problem and document the parameter tuning *** addition,we compare the prediction effectiveness of charging and discharging features modeled individually and in combination,determine the choice of charging and discharging features to be modeled in combination,and visualize the multidimensional data for fault *** results show that the unsupervised learning algorithm is effective in visualizing and predicting vehicle core conformance faults,and can accurately predict faults in real ***“distance+boxplot”algorithm shows the best performance with a prediction accuracy of 80%,a recall rate of 100%,and an F1 of *** proposed approach can be applied to monitor battery consistency faults in real time and reduce the possibility of disasters arising from consistency faults.

关键词： battery consistency charging segment data unsupervised learning

Neurotoxicity of tetramethylammonium ion on larval and juvenile zebrafish:Effects on neurobehaviors and multiple biomarkers

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Journal of Environmental Sciences 2024年第9期143卷 138-147页

作者： Ruixin Zhang Rui Wang Jiajun chang GDaniel Sheng Daqiang Yin Key Laboratory of Yangtze River Water Environment Ministry of EducationCollege of Environmental Science and EngineeringTongji UniversityShanghai 200092China Shanghai Institute of Pollution Control and Ecological Security Shanghai 200092China

Tetramethylammonium hydroxide(TMAH)is an important compound that utilized and released by the rapidly expanding semiconductor industry,which could hardly be removed by the conventional wastewater treatment *** a cholinergic agonist,the tetramethylammonium ion(TMA^(+))has been reported to induce toxicity to muscular and respiratory systems of mammals and human,however the toxicity on aquatic biota remains poorly *** investigated the neurotoxic effects of TMA^(+)exposure on zebrafish,based on neurobehavior tests and a series of *** inhibitions on the swimming distance of zebrafish larvae were observed when the exposure level exceeded 50 mg/L,and significant alterations on swimming path angles(straight and deflective movements)occurred even at 10 mg/*** tested neurobehavioral endpoints of zebrafish larvae were significantly positively correlated with reactive oxygen species(ROS)and malondialdehyde(MDA),significantly negatively related with the activities of antioxidant enzymes,but not significantly correlated with the level of acetylcholinesterase(AChE).Such relationship indicates that the observed neurotoxic effects on swimming behavior of zebrafish larvae is mainly driven by oxidative stress,rather than the alterations of *** the highest exposure concentration(200 mg/L),TMA^(+)evoked more severe toxicity on zebrafish juveniles,showing significantly stronger elevation on the MDA activity,and greater inhibitions on the activities of antioxidant enzymes and ACh E,suggesting juveniles were more susceptible to TMA^(+)exposure than larval zebrafish.

关键词： Tetramethylammonium Zebrafish Oxidative stress Acetylcholinesterase Neurobehavior

Mn-modified nitrogen-doped Pt-based electrocatalyst for efficient oxygen reduction in aluminum-air batteries

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Nano Research 2024年第8期17卷 7126-7135页

作者： Li Gao Yang Song Xuebing Xu chang Li Chaoquan Hu State Key Laboratory of Mesoscience and Engineering Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China Zhongke Nanjing Institute of Green Manufacturing Industry Nanjing 211135China

In this study,a Mn-modified Pt-based catalyst loaded on nitrogen-doped Ketjen black(Mn-Pt/NKB)is prepared using a simple ethylene glycol reduction *** size of Pt nanoparticles(NPs)is effectively controlled by doping with Mn and *** the smallest average particle size of 1.7 nm,Mn-Pt/NKB demonstrates half-wave potentials of 0.890 and 0.688 V in the alkaline and neutral electrolytes,respectively,which are superior to those of commercial platinum on activated carbon(Pt/C).When applied as an air cathode in aluminum-air battery,it exhibits ultra-high power densities of 190(alkaline)and 26.2 mW·cm^(−2)(neutral).Moreover,the voltage remains stable after 5 h of *** practical application performance of the Mn-Pt/NKB catalyst in an aluminum-air battery is better than that of commercial Pt/***,the oxygen reduction reaction(ORR)mechanism on surfaces with different particle sizes is analyzed using density functional *** cracking is the major pathway on the surface of the small particles with lower energy consumption of 0.5 eV,while water molecule cleavage is the major pathway on the surface of the large particles with higher energy consumption of 0.97 *** lower energy consumption of the oxygen cracking pathway further confirms the ORR mechanism for higher activity on small-sized *** study provides a direction for the rational design of Pt-based catalysts for ORR and sheds light on the commercial development of aluminum-air batteries.

关键词： oxygen reduction reaction precious metal catalysts aluminum-air battery density functional theory(DFT)calculations reaction pathway

Recent progress on the synthesis of defective UiO-66 for thermal catalysis

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Nano Research 2024年第10期17卷 8653-8670页

作者： Qing Feng Caoyu Yang Lin chang Guodong Li Zhiyong Tang CAS Key Laboratory of Nanosystem and Hierarchical Fabrication CAS Center for Excellence in NanoscienceNational Center for Nanoscience and TechnologyBeijing 100190China School of Nanoscience and Engineering University of Chinese Academy of SciencesBeijing 100049China

Zirconium terephthalate UiO-66 has aroused great interest in catalysis since it exhibits significant flexibility and compatibility for accommodating a high number of defects as well as exceptional thermal and chemical *** now,many works have focused on the modulations of the Zr6-oxo clusters in UiO-66 in terms of diverse synthesis,advanced characterizations,and their catalytic *** achieve high catalytic efficiency,it is still highly desired for rationally constructing and modulating the Zr6-oxo clusters with exposed catalytic sites and diverse microenvironments for advanced *** this review,we provide a comprehensive summary of recent progress on the synthesis of defective UiO-66,qualitative and quantitative characterizations,as well as a logical overview of heterogeneous catalytic applications over the past few ***,the outlooks for the research paradigm of defective UiO-66 are discussed.

关键词： defective UiO-66 de novo synthesis post-synthetic treatment characterization thermal catalysis

Optimizing evasive maneuvering of planes using a flight quality driven model

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Science China(Information Sciences) 2024年第3期67卷 197-208页

作者： chang LIU Shaoshan SUN Chenggang TAO Yingxin SHOU Bin XU School of Automation Northwestern Polytechnical University Chengdu Aircraft Design & Research Institute of AVIC

This paper investigates the optimal evasive maneuver for a plane to avoid an incoming missile. To accurately model the system dynamics while improving computational efficiency, a simplified plane model based on flight quality is established. A missile model with proportional guidance is also *** problem of determining the optimal evasion plane maneuver is formulated. The Gauss pseudospectral method(GPM) is proposed as a solution to find the optimal maneuver. The optimized maneuver is validated by testing it on a high-fidelity 6-degree-of-freedom(6-DOF) model, which demonstrates the effectiveness of the proposed simplified plane model. The Monte Carlo method is employed to evaluate the capability of the plane to evade missiles in various scenarios and elucidate general principles for successful evasion.

关键词： optimal maneuver flying quality evasive strategy pursuit-evasion game air-to-air combat