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Effect of Low-Temperature Thermal Oxidation on the Capillary Performance of Sintered Copper Powder Wicks

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Journal of Thermal Science 2024年第1期33卷 29-40页

作者： ZHU Minghan FANG Runquan HU Yanxin ZHANG Jiangyun SHAO Dan HUANG Jin School of material and Energy Guangdong University of TechnologyGuangzhou 510006China School of Electric Power Engineering Guangdong Polytechnic of Water Resources and Electric EngineeringGuangzhou 510006China research into Artifacts Guangdong Key Laboratory of Battery SafetyGuangzhou Institute of Energy testingGuangzhou 511447China

In this study,a composite powder capillary wick is prepared,manufactured by sintering copper powder and surface treated by low-temperature thermal *** is used to improve the performance of the capillary *** forced flow method and infrared imaging method are used to test the permeability and capillary performance of the *** effects of different oxidation temperatures on the performance of capillary wick are *** experimental results show that the wetting performance of the oxidized samples is significantly *** the increase of oxidation temperature,the permeability *** capillary height and velocity of the thermally oxidized samples are significantly higher than those of the untreated capillary ***,the oxidation temperature needs to be adjusted to obtain the best capillary *** highest capillary performance is found at oxidation temperature of 300℃,with an increase of 46% compared to the untreated *** with other composite wicks show that the sample with an oxidation temperature of 300℃ has competitive capillary performance,making it a favorable alternative to two-phase heat transfer *** study shows that combining low-temperature thermal oxidation technology with powder sintering is a convenient and effective method to improve the capillary performance of powder wicks.

关键词： low-temperature thermal oxidation capillary performance copper powder permeability

Effect of annealing conditions on surface morphology and ferroelectric domain structures of BiFeO_(3)thin films

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Journal of Advanced Dielectrics 2024年第2期14卷 77-82页

作者： Minchuan Liang Jia Yang Huayu Yang Chen Liang Zhenyue Nie Hui Ai Tong Zhang Ji Ma Houbing Huang Jing Wang Advanced research institute of Multidisciplinary Science and School of Materials Science and Engineering Beijing Institute of TechnologyBeijing 100081P.R.China Analysis and testing Center Beijing institute of Technology Beijing 100081P.R.China School of material Science and Engineering Kunming University of Science and Technology Kunming Yunnan 650093P.R.China

Ferroelectric materials are widely used in the applications of electronic devices due to their robust spontaneous *** surface roughness of ferroelectric thin films,which is closely related to the morphology,can play an important role in determining the ferroelectric domain *** this work,we have investigated the influence of annealing conditions on the surface morphology of epitaxial BiFeO_(3)and SrRuO_(3)thin films prepared by pulsed laser deposition on SrTiO_(3)(001)*** is found that the morphology of the thin films is sensitive to the annealing time and cooling rate,and the corresponding surface roughness decreases with increasing annealing time and decreasing cooling *** addition,the ferroelectric domain structures of BiFeO_(3)films have been investigated by piezoelectric force microscopy,which shows a significant improvement in domain size and reverse piezoelectric response in the thin films with decreasing surface *** work provides a simple way to predict and improve the ferroelectric domain structures by in situ annealing.

关键词： BiFeO_(3)thin films in situ annealing surface morphology domain structure

Ferroelastic domain engineering in layered-perovskite Bi_(2)WO_(6)thin films by post-annealing

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Journal of Advanced Dielectrics 2024年第2期14卷 71-76页

作者： Jia Yang Minchuan Liang Huayu Yang Hui Ai Tong Zhang Qing Han Ji Ma Houbing Huang Jing Wang Advanced research institute of Multidisciplinary Science and School of materials Science and Engineering Beijing institute of Technology Beijing 100081P.R.China Analysis&testing Center Beijing Institute of Technology Beijing 100081P.R.China School of material Science and Engineering Kunming University of Science and Technology Kunming Yunnan 650093P.R.China

Due to the strong magneto-elastic coupling in ferromagnetic/ferroelectric heterostructures and the potential applications in lowpower magnetoelectric nanodevices,ferroelastic domains and the corresponding dynamic evolution under external stimuli have attracted intense research *** pulsed laser deposition method,we have successfully grown layered-perovskite Bi_(2)WO_(6)thin films on SrTiO_(3)(001)***,for the as-grown thin films with step-flow morphology,the relationship between ferroelastic domain number and size shows a normal distribution,which is similar to the Boltzman distribution for confined gas molecules at *** addition,with post-annealing,the thin films with as-grown island-like morphology can be optimized for layered morphology,and the initial small ferroelastic domains can grow into large *** study provides an effective strategy for ferroelastic domain engineering,which can be applied for the design of multiferroic heterostructures and low-power nanodevices.

关键词： Aurivillius oxides Bi_(2)WO_(6)thin films domain structure Boltzman distribution post-annealing

Attenuation of ground vibrations due to different technical sources

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Earthquake Engineering and Engineering Vibration 2010年第3期9卷 337-344页

作者： L.Auersch S.Said federal institute of material research and testing

The attenuation of technically induced surface waves is studied theoretically and experimentally. In this paper, nineteen measurements of ground vibrations induced by eight different technical sources including road and rail traffic, vibratory and impulsive construction work or pile driving, explosions, hammer impulses and mass drops are described, and it is shown that the technically induced ground vibrations exhibit a power-law attenuation v - r ~ where the exponents q are in the range of 0.5 to 2.0 and depend on the source types. Comparisons performed demonstrate that the measured exponents are considerably higher than theoretically expected. Some potential effects on ground vibration attenuation are theoretically analyzed. The most important effect is due to the material or scattering damping. Each frequency component is attenuated exponentially as exp（-kr）, but for a broad-band excitation, the sum of the exponential laws also yields a power law but with a high exponent. Additional effects are discussed, for example the dispersion of the Rayleigh wave due to soil layering, which yields an additional exponent of 0.5 in cases of impulsive loading.

关键词： wave attenuation environmental vibrations field tests material damping scattering damping Rayleigh wave

Polyoxometalate as the assembly material to self-assembled Ni(OH)_(2) nanosheets with electrocatalytic performance

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Nano research 2024年第8期17卷 7061-7067页

作者： Danyang He Tianyang Li Luozhen Jiang Fei Wang Zihao Xing Nan Wang Zhiyu Jia Guo-Yu Yang Key Laboratory of Cluster Science Ministry of EducationSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China Shanghai Advanced research institute Chinese Academy of ScienceShanghai 201210China Key Laboratory of Polyoxometalate and Reticular material Chemistry of Ministry of Education Facluty of ChemistryNortheast Normal UniversityChangchun 130024China

Developing non-noble metal-based electrocatalyst with high catalytic activity is essential for advancing hydrogen energy *** study introduces a hydrothermal method for synthesizing order Ni(OH)_(2) nanosheets,with H_(3)O_(40)PW_(12)(denoted as PW_(12))loaded onto reduced graphene oxide(rGO)coated on nickel foam(referred to as PW_(12)-Ni(OH)_(2)/rGO).This method contrasts with the electrodeposition of Ni(OH)_(2),where PW_(12) is added to the synthetic system to direct the assembly and morphology of the Ni(OH)_(2) through a hydrothermal *** this work,the nickel foam acts dual roles as both the substrate and the source of nickel for the formation of Ni(OH)_(2).The PW_(12)-Ni(OH)_(2)/rGO nanosheets,when successfully prepared and loaded onto the nickel foam(NF),exhibited superior electrocatalytic activity for the hydrogen evolution reaction(HER)in an alkaline electrolyte,achieving a current density of 10 mA·cm^(-2) at an overpotential of 69 ***,we endeavored to expand the application of this material towards the oxygen evolution reaction(OER)by preparing PW_(12)-(Fe/Co)Ni(OH)_(2)/rGO through the addition of metal *** nanocomposite displayed outstanding electrocatalytic activity in alkaline electrolytes,with a current density of 10 mA·cm^(-2)at an overpotential of 211 mV,and demonstrated excellent stability over a 50 h period in a 1 M KOH *** results presented in this paper offer an effective strategy for the preparation of polyoxometalate-based inorganic materials with diverse functionalities,applicable to both HER and OER.

关键词： polyoxometalate Ni(OH)_(2) assembly hydrogen evolution reaction oxygen evolution reaction

Electrochemical and colorimetric dual-signal detection of Staphylococcus aureus enterotoxin B based on AuPt bimetallic nanoparticles loaded Fe-N-C single atom nanocomposite

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Food Science and Human Wellness 2024年第4期13卷 2025-2035页

作者： Huan Liang Hongcheng Liu Haojian Lin Guobao Ning Xiaokang Lu Siying Ma Fei Liu Hui Zhao Canpeng Li School of Chemical Science and Technology Yunnan UniversityKey Laboratory of Medicinal Chemistry for Natural ResourceMinistry of EducationKunming 650091China institute of Quality Standard and testing Technology Yunnan Academy of Agricultural ScienceSupervision and Testing Center for Farm Product QualityMinistry of AgricultureKunming 650223China State Key Laboratory of Optoelectronic materials and Technologies Guangdong Province Key Laboratory of Display Material and TechnologySchool of Electronics and Information TechnologySun Yat-sen UniversityGuangzhou 510275China Laboratory for Conservation and Utilization of Bio-resource Yunnan UniversityKunming 650091China

Sensitive detection of Staphylococcus aureus enterotoxin B(SEB)is of importance for preventing food poisoning from threatening human *** this work,an electrochemical and colorimetric dual-signal detection assay of SEB was *** probe(Ab2/AuPt@Fe-N-C)was bound to SEB captured by Ab1,where the Ab2/AuPt@Fe-N-C triggered methylene blue degradation and resulted in the decrease of electrochemical ***,the probe catalyzed the oxidation of 3,3’,5,5’-tetramethyl biphenyl to generate a colorimetric absorbance at 652 *** the target was captured and formed a sandwich-like complex,the color changed from colorless to *** detection by colorimetric and electrochemical methods showed a linear relationship in the concentration ranges of 0.0002-10.0000 and 0.0005-10.0000 ng/mL,with limits of detection of 0.0667 and 0.1670 pg/mL,*** dual-signal biosensor was successfully used to detect SEB in milk and water samples,which has great potential in toxin detection in food and the environment.

关键词： Staphylococcus aureus enterotoxin Electrochemical immunosensor Colorimetric assay MOF@borophene composite Dual-functional Fe-N-C signal atom catalyst

Dimensional regulation in gigantic molybdenum blue wheels featuring{(W)Mo_(5)}motifs for enhanced proton conductivity

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Nano research 2024年第9期17卷 8261-8268页

作者： Yu-Lun Wu Jing Du Hai-Ying Zhang Ming-Jun Hou Qiao-Yue Li Wei-Chao Chen Kui-Zhan Shao Bo Zhu Chao Qin Xin-Long Wang Zhong-Min Su Key Laboratory of Polyoxometalate and Reticular material Chemistry of Ministry of Education Department of ChemistryNortheast Normal UniversityChangchun 130024China Hebei Key Laboratory of Organic Functional Molecules National Demonstration Center for Experimental Chemistry EducationTesting and Analysis CenterCollege of Chemistry and Materials ScienceHebei Normal UniversityShijiazhuang 050024China State Key Laboratory of Supramolecular Structure and materials Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China

Dimensional regulation in polyoxometalates is an effective strategy during the design and synthesis of polyoxometalates-based high proton conductors,but it is not available to ***,the precise regulation of dimensionality has been realized in an unprecedented gigantic molybdenum blue wheel family featuring pentagonal{(W)Mo5}motifs through optimizing the molar ratio of Mo/W,including[Gd_(2)Mo_(124)W_(14)O_(422)(H_(2)O)62]38-(0D-{Mo_(124)W_(14)},1),[Mo_(126)W_(14)O441(H_(2)O)51]^(70-)(1D-{Mo_(126)W_(14)}n,2),and[Mo_(124)W_(14)O_(430)(H_(2)O)50]60-(2D-{Mo_(124)W_(14)}n,3).Such important{(W)Mo5}structural motif brings new reactivity into gigantic Mo blue *** are different numbers and sites of{Mo2}defects in each wheel-shaped monomer in 1-3,which leads to the monomers of 2 and 3 to form 1D and 2D architectures via Mo-O-Mo covalent bonds driven by{Mo2}-mediated H_(2)O ligands substitution process,respectively,thus achieving the controllable dimensional *** expected,the proton conductivity of 3 is 10 times higher than that of 1 and 1.7 times higher than that of *** continuous proton hopping sites in 2D network are responsible for the enhanced proton conductivity with lower activation *** study highlights that this dimensional regulation approach remains great potential in preparing polyoxometalates-based high proton conductive materials.

关键词： polyoxometalate molybdenum blue wheels Mo/W mixed-addenda polyoxometalates dimensional regulation proton conduction

A Cu-Pd alloy catalyst with partial phase separation for the electrochemical CO_(2) reduction reaction

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Journal of Energy Chemistry 2024年第6期93卷 8-15,I0001页

作者： Gyeong Ho Han Jung Yong Seo Minji Kang Myung-gi Seo Youngheon Choi Soo Young Kim Sang Hyun Ahn School of Chemical Engineering and material Science Chung-Ang UniversitySeoul 06974Republic of Korea Lotte Chemical institute of Technology Daejeon 34110Republic of Korea Department of materials Science and Engineering Korea UniversitySeoul 02841Republic of Korea

Cu catalysts can convert CO_(2) through an electrochemical reduction reaction into a variety of useful carbon-based ***,this capability provides an obstacle to increasing the selectivity for a single ***,we report a simple fabrication method for a Cu-Pd alloy catalyst for use in a membrane electrode assembly(MEA)-based CO_(2) electrolyzer for the electrochemical CO_(2) reduction reaction(ECRR)with high selectivity for CO *** the composition of the Cu-Pd alloy catalyst was fabricated at 6:4,the selectivity for CO increased and the production of multi-carbon compounds and hydrogen is *** a Cu-Pd alloy catalyst with 6:4 ratio as the cathode of the MEAbased CO_(2) electrolyzer showed a CO faradaic efficiency of 92.8%at 2.4 V_(cell).We assumed that these results contributed from the crystal planes on the surface of the Cu-Pd *** phases of the Cu-Pd alloy catalyst were partially separated through annealing to fabricate a catalyst with high selectivity for CO at low voltage and C_(2)H_4 at high *** results of CO-stripping testing confirmed that when Cu partially separates from the lattice of the Cu-Pd alloy,the desorption of~*CO is suppressed,suggesting that C-C coupling reaction is favored.

关键词： Cu-Pd catalyst Electrodeposition Electrochemical carbon dioxide reduction Partial phase separation Membrane electrode assembly-based electrolyzer

Multi-field Coupled Inverse Hall–Petch Relations for Ferroelectric Nanocrystals

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Acta Mechanica Solida Sinica 2024年第1期37卷 139-147页

作者： Xiaodong Zhang Wei Yan Xuhui Lou Yujun Chen Zhihong Zhou Qingyuan Wang Lianhua Ma Xiaobao Tian Non-Destructive testing Laboratory School of Quality and Technical SupervisionHebei UniversityBaoding 071002China AVIC Huiyang Aviation Propeller Co. LtdBaoding 071051China Department of Mechanics and Engineering Sichuan UniversityChengdu 610065China Yibin institute of Industrial Technology Sichuan University Yibin ParkYibin 644000China research institute of Interdisciplinary Sciences(RISE) Dongguan University of TechnologyDongguan 523808China School of materials Science and Engineering Dongguan University of TechnologyDongguan 523808China

Tailoring grain size can improve the strength of polycrystals by regulating the proportion of grains to grain boundaries and the interaction *** the grain size decreases to the nanoscale,the deformation mechanism in polycrystals shifts from being primarily mediated by dislocations to deformation occurring within the grains and grain ***,the mechanism responsible for fine-grain strengthening in ferroelectric materials remains unclear,primarily due to the complex multi-field coupling effect arising from spontaneous *** molecular dynamics simulations,we investigate the strengthening mechanism of barium titanate(BaTiO3),with extremely fine-grain *** material exhibits an inverse Hall–Petch relationship between grain size and strength,rooting in the inhomogeneous concentration of atomic strain and grain ***,we present a theoretical model to predict the transition from the inverse Hall–Petch stage to the Hall–Petch stage based on strength variations with size,which aligns well with the simulation *** has been found that the piezoelectric properties of the BaTiO3 are affected by polarization domain switching at various grain *** study enhances our understanding of the atomic-scale mechanisms that contribute to the performance evolution of fine-grain nano-ferroelectric *** also provides valuable insights into the design of extremely small-scale ferroelectric components.

关键词： Ferroelectrics Multi-field coupling Molecular dynamics Fine-grain reinforcement Inverse Hall-Petch effect