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Effect of Heat Treatment on Microstructure and Mechanical Properties of Multiscale SiC_p Hybrid Reinforced 6061 Aluminum Matrix Composites

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 174-181页

作者：吴健铭许晓静 ZHANG xu LUO Yuntian LI Shuaidi HUANG lin Institute for Advanced Manufacturing and Modern Equipment Technology Jiangsu UniversityZhenjiang 212013China

The performance of solid solution aging treatment on aluminum matrix composites prepared by powder metallurgy and reinforced with 6061 aluminum alloy powder as matrix;meanwhile, nano silicon carbide particles(nm Si Cp), submicron silicon carbide particles(1 μm Si Cp) and Ti particles were studied. The Al/Si Cp composite powder was prepared by high-energy ball milling, and then cold-pressed, sintered, hotextruded, and then heat-treated with different solution temperatures and aging times for the extruded composites. Optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy(EDS), X-ray diffractometer(XRD) and extrusion testing were used to analyze and test the microstructure and mechanical properties of aluminum matrix composites. The results show that after the multi-stage solid solution at 530 ℃×2 h+535 ℃×2 h+540 ℃×2 h, the particles are mainly equiaxed grains and uniformly distributed. There is no reinforcement agglomeration, and the surface is dense and the insoluble phase is basically dissolved. In the matrix, the strengthening effect is good, and the hardness and compressive strength are 179.43 HV and 680.42 MPa, respectively. Under this solution process, when the aluminum matrix composites are aged at 170 ℃ for 10 h, the hardness and compressive strength can reach their peaks and increase to 195.82 HV and 721.48 MPa, respectively.

关键词： aluminum matrix composites Si C particles multiscale hybrid enhancement heat treatment mechanical properties

The configuration of Au^(δ+)-ZrO_(2)^(δ−)species induced activation enhances electrocatalytic CO_(2)to formate conversion

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Nano Research 2024年第7期17卷 6006-6015页

作者： Yongjian Jia Yadi Zhang Mengque lin Yangyang Cheng Yanjie xu National Engineering Research Center for Technology and Equipment of Environmental Deposition Lanzhou Jiaotong UniversityLanzhou 730070China Key Lab of Opt-Electronic Technology and Intelligent Control of Ministry of Education Lanzhou Jiaotong UniversityLanzhou 730070China School of Environmental Engineering and Chemistry Luoyang Institute of Science and TechnologyLuoyang 471023China

Electrochemical CO_(2)conversion into value-added chemicals is a promising technology to solve the greenhouse effect and recycle chemical ***,the electrochemical CO_(2)reduction reaction(e-CO_(2)RR)is seriously compromised by weak CO_(2)adsorption and a rough CO_(2)activation process based on the chemical inertness of the CO_(2)molecule and the formed fragile metal–C/O *** this paper,we designed and fabricated Au particles embedded in ZrO_(2).The configuration of Au particles being of positive charge and ZrO_(2)with negative charge is induced and generated by metal–support interactions(MSIs).As a result,Au/ZrO_(2)@C presents a big difference in the CO_(2)conversion compared with the known work,affording a formate yield of 112.5μmol·cm^(−2)·h^(−1)at−1.1 V *** hydrogen electrode(RHE),and a max formate Faradaic efficiency of up to 94.1%at−0.9 V *** superior performance was attributed to the activated Au–ZrO_(2)interface to form the Au^(δ+)*** insitu Fourier transform infrared(FTIR)spectroscopy and theoretical calculations show that the MSIs configuration can be inclined to the*OCO intermediate generation on Au^(δ+)species activating CO_(2)molecules and then accelerate the formation of the*OCHO intermediate in e-CO_(2)RR,thereby favoring the CO_(2)conversion to formate.

关键词： electrochemical CO_(2)reduction reaction(e-CO_(2)RR) Au_(δ+)species formic acid *OCHO intermediate metal-support interactions

Efficient Spin-Flip between Charge-Transfer States for High-Performance Electroluminescence, without an Intermediate Locally Excited State

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Research 2024年第1期2023卷 339-349页

作者： Donghai Zhang Shanshan Jiang Xiaodong Tao Fulin lin lingyi Meng xu-lin Chen Can-Zhong Lu State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhouFujian 350002China Fujian Science and Technology Innovation Laboratory for Optoelectronic Information of China FuzhouFujian 350108China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstitutesChinese Academy of SciencesXiamenFujian 361021China University of Chinese Academy of Sciences Beijing 100049China

Thermally activated delayed fluorescence(TADF)materials with both high photoluminescence quantum yield(PLQY)and fast reverse intersystem crossing(RISC)are strongly desired to realize efficient and stable organic light-emitting diodes(OLEDs).Control of excited-state dynamics via molecular design plays a central role in optimizing the PLQY and RISC rate of TADF materials but remains ***,3 TADF emitters possessing similar molecular structures,similar high PLQYs(89.5%to 96.3%),and approximate energy levels of the lowest excited singlet states(S_(1)),but significantly different spin-flipping RISC rates(0.03×10^(6) s^(−1) vs.2.26×10^(6) s^(−1))and exciton lifetime(297.1 to 332.8μs vs.6.0μs)were systematically synthesized to deeply investigate the feasibility of spin-flip between charge-transfer excited states(^(3)CT–^(1)CT)transition.

关键词： transition lifetime desired

From charge storage mechanism to performance:A strategy toward boosted lithium/sodium storage through heterostructure optimization

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Journal of Energy Chemistry 2024年第1期88卷 112-124,I0003页

作者： Xiaoke Zhang Guangfa Deng Mianying Huang Zhaohui xu Jianlin Huang xuan xu Zhiguang xu Maochan Li Lei Hu Xiaoming lin Key Laboratory of Theoretical Chemistry of Environment Ministry of EducationSchool of ChemistrySouth China Normal UniversityGuangzhou 510006GuangdongChina Anhui Laboratory of Functional Coordinated Complexes for Materials Chemistry and Application School of Chemical and Environmental EngineeringAnhui Polytechnic UniversityWuhu 241000AnhuiChina National Engineering Research Center for Carbohydrate Synthesis Key Lab of Fluorine and Silicon for Energy Materials and Chemistry of Ministry of EducationJiangxi Normal UniversityNanchang 330022JiangxiChina

Solving the problems of low electrical conductivity and poor cycling durability in transition metal oxidesbased anode materials for lithium-ion batteries(LIBs)and sodium-ion batteries(SIBs)has already turned into an urgent *** this paper,we successfully synthesized Co_(2)VO_(4)/Co compounds with Co-VMOF(metal-organic framework)as a sacrificial template and investigated their electrochemical mechanism in order to improve the electrochemical properties of LIBs and *** optimized heaping configuration and the existence of metallic Co catalyzed the formation of radical ions,thereby facilitating higher conductivity,shortening Li+and Na+transport paths,and providing more active ***_(2)VO_(4)/Co constructed with 2-methylimidazole as a ligand showed a discharge capacity of 1605.1 mA h g^(-1)after 300 cycles at 0.1 A g^(-1)in LIB and 677.2 mA h g^(-1)in *** functional theory(DFT)calculation emphasizes the crucial role of Co_(2)VO_(4)/Co in enhancing electrode conductivity,decreasing the migratory energy barrier,and thereby strengthening electrochemical *** heterostructure building technique may pave the way for the development of high-performance LIBs and ***,the problem of the low first-loop coulombic efficiency faced by transition metal oxides is improved.

关键词： Metal-organic framework Heterostructure Lithium-ion batteries Sodium-ion batteries DFT calculation

Enhancing cellular behavior in repaired tissue via silk fibroin-integrated triboelectric nanogenerators

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Microsystems & Nanoengineering 2024年第3期10卷 137-147页

作者： Zhelin Li Shuxing xu Zijie xu Sheng Shu Guanlin Liu Jianda Zhou Ding lin Wei Tang Changsha Aier Eye Hospital Aier School of OphthalmologyCentral South UniversityChangshaHunanChina The Xiangya Hospital Central South UniversityChangshaHunanChina Beijing Institute of Nanoenergy and Nanosystems Chinese Academy of SciencesBeijing 101400China Center on Nanoenergy Research School of Physical Science&TechnologyGuangxi UniversityNanning 530004China School of Nanoscience and Technology University of Chinese Academy of SciencesBeijing 100049China Department of Plastic Surgery the Third Xiangya HospitalChangshaHunanChina

Triboelectric nanogenerators(TENGs)have emerged as a promising approach for generating electricity and providing electrical stimuli in medical electronic *** their potential benefits,the clinical implementation of TENGs faces challenges such as skin compliance and a lack of comprehensive assessment regarding their biosafety and ***,further research is imperative to overcome these limitations and unlock the full potential of TENGs in various biomedical *** this study,we present a flexible silk fibroin-based triboelectric nanogenerator(SFB-TENG)that features an on-skin substrate and is characterized by excellent skin compliance and air/water *** range of electrical output generated by the SFB-TENG was shown to facilitate the migration and proliferation of Hy926,NIH-3T3 and RSC96 ***,apoptosis of fibroblast NIH-3T3 cells was observed when the output voltage increased to more than 20 V at a frequency of 2 *** addition,the moderate electrical stimulation provided by the SFB-TENG promoted the cell proliferation cycle in Hy926 *** research highlights the efficacy of a TENG system featuring a flexible and skin-friendly design,as well as its safe operating conditions for use in biomedical *** findings position TENGs as highly promising candidates for practical applications in the field of tissue regeneration.

关键词： overcome spite generating

In-situ analysis and genetic investigation of Li-bearing minerals in McDermitt clay-type lithium deposit,Nevada,USA

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Acta Geochimica 2024年第3期43卷 478-488页

作者： Yi Cui Hanjie Wen Zhengbing Zhou Kunyue ling lin xu Shirong Liu Fei xu School of Earth Sciences East China University of TechnologyNanchang 330013China State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of Earth Sciences and Resources Chang’an UniversityXi’an 710054China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China State Key Laboratory of Environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China

Clay-type Li deposits are poised to play a pivotal role in addressing the surging global demand for *** McDermitt clay-type Li deposit,located in Nevada,is the largest Li deposit in the United States,with Li hosted by a clay-rich sequence of smectite-dominated intervals and illite-dominated intervals,***,the occurrence of Li and the genesis of Li-bearing minerals within smectite-dominated intervals have not been thoroughly investigated in previous ***,we studied the mineralogy,the in-situ Li distribution,and the bonding environments of Li within the smectite intervals using a combination of instru-mental techniques including scanning electron microscope,transmission electron microscope,time-of-flight secondary ion mass spectrometry,and nuclear magnetic *** results indicate that the smectite exhibits low crystallinity characteristics of lacustrine clay authigenesis and is com-monly found tofill the interstices among volcanic minerals or envelop them;Li is mainly hosted by Mg-smectite rather than the volcanic *** the tuffaceous sediment samples,the volcanic glass has undergone a transformation,resulting in its complete disappearance and alteration into clay *** to the octahedral sites of Mg-smectite bounded in Li,it is referred to be *** interpret that the hectorite’s precipitation occurs in a high saline-alkaline water environment,a result of McDermitt *** conclusion can be supported by the coexistence of spherulitic calcite and ***,this study confirms hectorite as the main Li-bearing mineral and increases the understanding of the genetic model of hectorite formation in intracontinental caldera basins.

关键词： McDermitt caldera Lithium occurrence Tuffaceous sediments Mineralogy Hectorite neoformation

Ultrathin curved PdNiRu nanosheets as bifunctional catalysts for oxygen reduction and ethylene glycol oxidation

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Nano Research 2024年第5期17卷 3777-3784页

作者： Xianzeng Li Tingyu Lu Huan Pang Mingyi Zhang Dongdong xu lin xu Min Han Jun Yang Jiangsu Key Laboratory of New Power Batteries Jiangsu Collaborative Innovation Center of Biomedical Functional MaterialsSchool of Chemistry and Materials ScienceNanjing Normal UniversityNanjing 210023China Fujian Cross Strait Institute of Flexible Electronics(Future Technology) Fujian Normal UniversityFuzhou 350117China State Key Laboratory of Multiphase Complex Systems Institute of Process EngineeringChinese Academy of SciencesBeijing 100190China State Key Laboratory of Coordination Chemistry Nanjing UniversityNanjing 210023China School of Chemistry and Chemical Engineering Yangzhou UniversityYangzhou 225009China Key Laboratory for Photonic and Electronic Bandgap Materials Ministry of EducationSchool of Physics and Electronic EngineeringHarbin Normal UniversityHarbin 150025China

Pd-based metallic nanosheets with advanced physicochemical properties have been widely prepared and employed in various electrocatalytic ***,few concerns were focused on their multiple performances in different ***,highly curved and ultrathin PdNiRu nanosheets(NSs)are developed by facile wet-chemistry strategy and exhibit excellent electrocatalytic performance toward both oxygen reduction reaction(ORR)and ethylene glycol oxidation reaction(EGOR).Owing to the synergistically structural(e.g.,ultrathin,curved,defects/steps-rich)and compositional(ternary alloy)advantages,PdNiRu NSs exhibited enhanced ORR and EGOR specific/mass activities and better stability/durability than control *** specific activity(5.52 mA·cm^(−2))and mass activity(1.13 A·mg_(Pd)^(−1))of the PdNiRu NSs in ORR are 4.8 and 3.4 times as the ones of commercial Pt/C,*** mass activity of PdNiRu NSs(3.86 A·mg_(Pd)^(−1))in EGOR is 2.6 times as commercial Pd/C(1.51 A·mg_(Pd)^(−1)).This study is helpful for the development of desired electrocatalysts with multi-functional application in practical fuel cells.

关键词： ultrathin nanosheets noble metal electrocatalysts bifunctional

Design and Implementation of a High-Sensitivity Magnetic Sensing System Based on GMI Effect

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Journal of Beijing Institute of Technology 2024年第3期33卷 237-247页

作者： Wenzhu Wu Ming xu Changlin Han Junquan Tang Jia xu lin xu Mingxin Qin Department of Electronic Engineering Army Medical UniversityChongqing 400038China Chongqing Medical and Pharmaceutical College Chongqing 401331China Department of Intelligence Science and Technology National University of Defense TechnologyChangshaChangsha 410073China Intelligent Game and Decision Lab Beijing 100091China

A high-sensitivity magnetic sensing system based on giant magneto-impedance(GMI)effect is designed and *** system comprises a GMI sensor equipped with a gradient probe and an signal acquisition and processing module.A segmented superposition algorithm is used to increase target signal and reduce the random *** results show that under unshielded,room temperature conditions,the system achieves successful detection of weak magnetic fields down to 2 pT with a notable sensitivity of 1.84×10^(8)V/T(G=1000).By applying 17 overlays,the segmented superposition algorithm increases the power proportion of the target signal at 31 Hz from6.89%to 45.91%,surpassing the power proportion of the 2 Hz low-frequency interference ***,it reduces the power proportion of the 20 Hz random *** segmented superposition process effectively cancels out certain random noise elements,leading to a reduction in their respective power *** high-sensitivity magnetic sensing system features a simple structure,and is easy to operate,making it highly valuable for both practical applications and broader dissemination.

关键词： high-sensitivity magnetic field sensing system GMI effect segmented superposition algorithm

Joint Communication-Caching-Computing Resource Allocation for Bidirectional Data Computation in IRS-Assisted Hybrid UAV-Terrestrial Network

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Chinese Journal of Electronics 2024年第4期33卷 1093-1103页

作者： Yangzhe LIAO lin LIU Yuanyan SONG Ning xu School of Information Engineering Wuhan University of Technology

Joint communication-caching-computing resource allocation in wireless inland waterway communications enables resource-constrained unmanned surface vehicles(USVs) to provision computation-intensive and latencysensitive tasks forward beyond fifth-generation(B5G) and sixth-generation(6G) era. The power of such resource allocation cannot be fully studied unless bidirectional data computation is properly managed. A novel intelligent reflecting surface(IRS)-assisted hybrid UAV-terrestrial network architecture is proposed with bidirectional tasks. The sum of uplink and downlink bandwidth minimization problem is formulated by jointly considering link quality, task execution mode selection, UAVs trajectory, and task execution latency constraints. A heuristic algorithm is proposed to solve the formulated challenging problem. We divide the original challenging problem into two subproblems, i.e., the joint optimization problem of USVs offloading decision, caching decision and task execution mode selection, and the joint optimization problem of UAVs trajectory and IRS phase shift-vector design. The Karush–Kuhn–Tucker conditions are utilized to solve the first subproblem and the enhanced differential evolution algorithm is proposed to solve the latter one. The results show that the proposed solution can significantly decrease bandwidth consumption in comparison with the selected advanced algorithms. The results also prove that the sum of bandwidth can be remarkably decreased by implementing a higher number of IRS elements.

关键词： Wireless communication Heuristic algorithms Bandwidth Network architecture Downlink Trajectory Resource management