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Journal of Advanced Ceramics 2024年第5期13卷 641-651页

作者： Xi Yan Hongjiang Pan Yixin Zhang Tianyu Yang Yangwei Wang Kun Huang Chongyu Wang Jing Feng Zhenhua Ge Faculty of Materials science and Engineering Kunming University of Science and TechnologyKunming 650093China

In situ phase separation precipitates play an important role in enhancing the thermoelectric properties of copper sulfides by suppressing phonon *** this study,Cu1.8S composites were fabricated by melting reactions and spark plasma *** complex structures,namely,micron-PbS,Sb_(2)S_(3),nano-FeS,and multiscale pores,originate from the introduction of FePb_(4)Sb_(6)S_(14)into the Cu1.8S *** effective element(Fe)doping and multiscale precipitates,the Cu_(1.8)S+0.5 wt%FePb_(4)Sb_(6)S_(14)bulk composite reached a high dimensionless figure of merit(ZT)value of 1.1 at 773 ***,the modulus obtained for this sample was approximately 40.27 GPa,which was higher than that of the pristine *** study provides a novel strategy for realizing heterovalent doping while forming various precipitates via in situ phase separation by natural minerals,which has been proven to be effective in improving the thermoelectric and mechanical performance of copper sulfides and is worth promoting in other thermoelectric systems.

关键词： in situ precipitates jamesonite natural mineral thermoelectric copper sulfides

Towards growth of pure AB-stacked bilayer graphene single crystals

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Nano Research 2024年第5期17卷 4616-4621页

作者： Xiaowen Zhang Tao Zhou Yunlong Ren Zuo Feng Ruixi Qiao Qinghe Wang Bin Wang Jinxia Bai Muhong Wu Zhilie Tang Xu Zhou Kaihui Liu Xiaozhi Xu Guangdong Basic Research Center of Excellence for Structure and Fundamental Interactions of Matter Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum MaterialsSchool of PhysicsSouth China Normal UniversityGuangzhou 510006China Guangdong-Hong Kong Joint laboratory of Quantum Matter School of PhysicsSouth China Normal UniversityGuangzhou 510006China Physical science and Engineering Division King Abdullah University of Science and TechnologyThuwal 23955–6900Saudi Arabia State key laboratory for Mesoscopic Physics Frontiers Science Center for Nano-optoelectronicsSchool of PhysicsPeking UniversityBeijing 100871China Institute for Frontier science Nanjing University of Aeronautics and AstronauticsNanjing 210094China International Centre for Quantum Materials Collaborative Innovation Centre of Quantum MatterPeking UniversityBeijing 100871China Songshan Lake Materials laboratory Institute of PhysicsChinese Academy of SciencesDongguan 523808China

Given its intriguing band structure and unique tunable bandgap,AB-stacked bilayer graphene has great potentials in the applications of high-end electronics,optoelectronics and *** epitaxial growth of AB-stacked single-crystal bilayer graphene films requires a strict AB-stacked lattice,identical orientations and seamless stitching of bilayer graphene ***,the particles inevitably present on the metal surface that produced during high temperature growth would induce random orientations,twisted stacking islands,and uncontrollable multilayers,which is a great challenge to ***,we propose a heat-resisting-box assisted strategy to produce nearly pure AB-stacked bilayer graphene single-crystal films on Cu/Ni(111)*** our technique,the particles on the Cu/Ni(111)surface are effectively eliminated,which greatly minimizes the occurrence of randomly twisted islands and uncontrollable *** as-grown AB-stacked bilayer graphene films show>99%alignment and>99%AB stacking *** work provides a promising method towards the growth of pure AB-stacked bilayer graphene single crystals and would accelerate its device applications.

关键词： bilayer graphene AB stacking uniform growth heat-resisting box

Dynamic lithium-compensation mechanism for densification of garnet-type Li_(7)La_(3)Zr_(2)O_(12)electrolyte by Li_(2)O atmosphere buffer pair

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Nano Research 2024年第7期17卷 6184-6191页

作者： Chujun Zheng Ya Chen Haoxin Dong Yan Lu Jun Jin Zhaoyin Wen CAS key laboratory of Materials for Energy Conversion Shanghai Institute of CeramicsChinese Academy of ScienceShanghai 200050China State key Lab High Performance Ceram and Superfine Shanghai Institute of CeramicsChinese Academy of SciencesShanghai 200050China Center of Materials science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China

Solid-state lithium metal batteries are one of the most promising options for next-generation batteries pursuing high-energy density and ***,the inevitable volatilization of lithium compounds during sintering leads to low relative density and low ionic conductivity of solid-state ***,the dynamic lithium-compensation mechanism is proposed to facilitate the densification of Ta-substituted garnet-type electrolyte(Li_(6.5)La_(3)Zr_(1.5)Ta_(0.5)O_(12)(LLZT))through the reversible manipulating of Li_(2)O ***_(2)ZrO_(3)is used as mother powder additive,which reacts with Li_(2)O in sintering atmosphere and forms Li_(6)Zr_(2)O_(7).Li_(2)ZrO_(3)/Li_(6)Zr_(2)O_(7)buffer pair manipulates the sintering Li_(2)O atmosphere,which is vital for LLZT,within the Li_(2)O partial pressure range corresponding to Li_(2)ZrO_(3)and Li_(6)Zr_(2)O_(7).Furthermore,the reversibility mechanism of buffer pair for Li_(2)O absorption and release is *** obtained LLZT exhibits a relative density of over 96%and an ionic conductivity exceeding 7×10^(−4)S·cm^(−1)with no abnormal grain *** symmetric cell demonstrates an excellent lithium dendrite suppressing ability(stable cycling at a current density of 0.3 mA·cm^(−2)for over 1000 h).Such dynamic lithium-compensation strategy has been successfully applied in atmosphere manipulation of LLZT sintering process,which reduces the dependence of LLZT on the Li_(2)O atmosphere,making it conducive to large-scale preparation of electrolyte ceramics.

关键词： solid-state batteries garnet-type electrolyte high-density electrolyte dynamic lithium-compensation buffer pair

Storage and redistribution of anthropogenic CO_(2) in the western North Pacific:The role of subtropical mode water transportation

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Fundamental Research 2024年第1期4卷 103-112页

作者： Cheng-long Li Lei Han Wei-dong Zhai Di Qi Xu-chen Wang Hong-mei Lin Li-wen Zheng Institute of Marine science and technology Shandong UniversityQingdao 266237China China-ASEAN College of Marine science and technology Xiamen University MalaysiaSelangorMalaysia Southern Marine science and Engineering Guangdong laboratory(Zhuhai) Zhuhai 519080China Polar and Marine Research Institute Jimei UniversityXiamen 361021China key laboratory of Marine Chemistry Theory and technology and Frontiers Science Center for Deep Ocean Multispheres and Earth SystemMinistry of EducationOcean University of ChinaQingdao 266100China Center for Isotope Geochemistry and Geochronology Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao 266237China Weihai Institute of Marine Ecology and Economy Research Weihai 264400China

Oceanic uptake and storage of anthropogenic CO_(2)(CANT)are regulated by ocean circulation and *** decipher the storage and redistribution of CANT in the western North Pacific,where a major CANT sink develops,we investigated the water column carbonate system,dissolved inorganic radiocarbon and ancillary parameters in May and August 2018,spanning the Kuroshio Extension(KE,35-39°N),Kuroshio Recirculation(KR,27-35°N)and subtropical(21-27°N)*** column CANT inventories were estimated to be 40.5±1.1 mol m^(-2) in the KR zone and 37.2±0.9 mol m^(-2) in the subtropical *** comparison with historical data obtained in 2005,relatively high rates of increase of the CANT inventory of 1.05±0.20 and 1.03±0.12 mol m^(-2) yr^(-1) in the recent decade were obtained in the KR and subtropical zones,*** water-mass-based analyses suggest that formation and transport of subtropical mode water dominate the deep penetration,storage,and redistribution of CANT in those two *** the KE zone,however,both the water column CANT inventory and the decadal CANT accumulation rate were small and uncertain owing to the dynamic hydrology,where the naturally uplifting isopycnal surfaces make CANT penetration relatively *** findings of this study improve the understanding of the spatiotemporal variations of CANT distribution,storage,and transport in the western North Pacific.

关键词： Oceanic CO_(2)uptake Anthropogenic CO_(2)storage Subtropical mode water Kuroshio extension Kuroshio recirculation Western North Pacific

Graphene oxide/Al_(2)O_(3)-based diffusive memristor cells:enabling robust crossbar arrays for multidisciplinary applications

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Rare Metals 2024年第8期43卷 3997-4005页

作者： Chen Liu Jun-Cheng Jin Yi-Ke Xiao Xin-Xin Wang Ping-Yuan Yan Yan-Qiang Cao Li-Yong Jiang Chuan-Xiang Sheng Ye-Feng Yu School of Microelectronics Nanjing University of Science and TechnologyNanjing 210094China School of science Nanjing University of Science and TechnologyNanjing210094China School of Information science and technology Fudan UniversityShanghai 200433China

A memristor crossbar array (MCA) has emerged as a cutting-edge platform for advanced memory and neuromorphic computing hardware,offering unrivaled bit-level storage density.A diffusive memristor cell (DMC) is particularly well-suited for MCA integration due to its inherent threshold switching characteristics as a selector,effectively addressing current sneak path *** DMC's potential is acknowledged,it necessitates furtherexploration of their practical applicability.

关键词： crossbar arrays offering

Function-reversible facets enabling SrTiO_(3)nanocrystals for improved photocatalytic hydrogen evolution

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Frontiers in Energy 2024年第1期18卷 101-109页

作者： Bin WANG Bei AN Xiaoqian LI Shaohua SHEN School of Physics Key Laboratory for Non-equilibrium Synthesis and Modulation of Condensed Matter(Ministry of Education)Key Laboratory of Shaanxi for Advanced Materials and Mesoscopic PhysicsXi’an Jiaotong UniversityXi’an 710049China International Research Center for Renewable Energy State Key Laboratory of Multiphase Flow in Power EngineeringXi’an Jiaotong UniversityXi’an 710049China

It has been widely reported that,for faceted nanocrystals,the two adjacent facets with different band levels contribute to promoted charge separation,and provide active sites for photocatalytic reduction and oxidation reaction,*** such cases,only one family of facets can be used for photocatalytic hydrogen ***,by using SrTiO_(3)nanocrystals enclosed by{023}and{001}facets as a model photocatalyst,this paper proposed a strategy to achieve the full-facets-utilization of the nanocrystals for photocatalytic hydrogen via chemically depositing Pt nanoparticles on all *** photo-deposition experiment of CdS provided direct evidence to demonstrate that the{023}facets which were responsible for photooxidation reaction can be function-reversed for photocatalytic hydrogen evolution after depositing Pt nanoparticles,together with the{001}***,the full-facets-utilization led to a much-improved activity for photocatalytic hydrogen,in contrast to those SrTiO_(3)nanocrystals with only{001}facets deposited by Pt nanoparticles via a photo-deposition method.

关键词： SrTiO_(3)nanocrystals crystal facets photocatalysis hydrogen evolution

Lamellar water induced quantized interlayer spacing of nanochannels walls

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Green Energy & Environment 2024年第2期9卷 356-365页

作者： Yue Zhang Chenlu Wang Chunlei Wang Yingyan Zhang Junhua Zhao Ning Wei Jiangsu key laboratory of Advanced Food Manufacturing Equipment and technology Jiangnan UniversityWuxi214122China key laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas Ministry of EducationNorthwest A&F UniversityYangling712100China Zhangjiang Lab Interdisplinary Research CenterShanghai Advanced Research InstituteChinese Academy of SciencesShanghai201210China key laboratory of Interfacial Physics and technology Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201800China Mechanical&Automotive Engineering School of EngineeringRMIT UniversityBundooraMelbourneVICVIC 3083Australia

The nanoscale confinement is of great important for the industrial applications of molecular sieve,desalination,and also essential in bio-logical transport *** efforts have been devoted to the influence of restricted spaces on the properties of confined ***,the situation of channel-wall is crucial but attracts less attention and remains *** fundamentally understand the mechanism of channel-walls in nanoconfinement,we investigated the interaction between the counter-force of the liquid and interlamellar spacing of nanochannel walls by considering the effect of both spatial confinement and surface *** results reveal that the nanochannel stables at only a few discrete spacing states when its confinement is within 1.4 *** quantized interlayer spacing is attributed to water molecules becoming laminated structures,and the stable states are corresponding to the monolayer,bilayer and trilayer water configurations,*** results can potentially help to understand the characterized interlayers spacing of graphene oxide membrane in *** findings are hold great promise in design of ion filtration membrane and artificial water/ion channels.

关键词： Nanoconfinement Quantized spacing Lamellar water layer MD simulations Entropy force

Low-resolution Kramers-Kronig detection system with error-feedback noise shaping

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science China(Information sciences) 2024年第5期67卷 259-269页

作者： Xiangyong DONG Zhenming YU Hongyu HUANG Kaixuan SUN Kun XU State key laboratory of Information Photonics and Optical Communications Beijing University of Posts and Telecommunications

In this paper, we investigated the effects of error-feedback noise shaping(EFNS) on a lowresolution Kramers-Kronig(KK) detection system for the first time. Both 16-ary quadrature amplitude modulation(16-QAM) and 64-ary quadrature amplitude modulation(64-QAM) were considered in the experiment. The carrier tone was added on the transmitter side using the virtual carrier-assisted single sideband(VCA-SSB) method to meet the minimum phase(MP) condition. Under the MP condition, KK detection only needs the intensity of the optical signal to be detected by one photodiode(PD) to retrieve the phase information. However, the virtual carrier tone increases the carrier-to-signal power ratio(CSPR), which results in a high peak-to-average power ratio(PAPR) at the transmitter, causing an increase in quantization noise. To mitigate quantization noise in the low-resolution KK detection system, EFNS was applied. The application of EFNS increased the optimal CSPR of the KK detection system and improved receiver sensitivity. Using a 4-bit DAC and the EFNS, 80 km transmission was achieved in the 60-Gbit/s 64-QAM KK detection system.

关键词： optical fiber communications Kramers-Kronig receiver error-feedback noise shaping quantization noise carrier-to-signal power ratio

Simultaneously enhancing the strength and ductility of as-extruded AlN/AZ91 composites via nano-precipitation and pyramidal slip

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Journal of Materials science & technology 2024年第5期172卷 240-254页

作者： Bin Zhang Yunxia Sun Tuo Liang Yunzhen Li Tian Li Jingchao Wang Ruiru Cai Changlin Yang State key laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

Age hardening is often used to optimize the mechanical properties of as-deformed Mg-based materials in industry,whereas the improvement of strength is usually accompanied by the significant loss of ductility,which hinders the application of Mg-based materials in structural *** the present work,high strength-ductility synergy(the yield strength of 263±9 MPa,ultimate tensile strength of 398±7 MPa and elongation to fracture of 34%±1%)was realized in as-extruded AlN/AZ91 composites after optimiz-ing aging *** characterization shows that AlN particles induced a large number of geometrically necessary dislocations around the AlN/Mg interface during extrusion,which decreased the nucleation barrier and provided more heterogeneous nucleation sites forγ-Mg 17 Al 12 continuous ***,95%of residual dislocations in as-extruded AlN/AZ91 composites were annihilated dur-ing peak-aging,suppressing the growth and coarsening of continuous ***,high density of nano-sizedγ-Mg 17 Al 12 continuous precipitates was produced in as-extruded AlN/AZ91 composites af-ter *** tension,gliding dislocations bypassed sphericalγ-Mg 17 Al 12 nano-precipitates by Orowan looping rather than cutting mechanism,which induced a strong block on dislocation *** high yield strength was mainly attributed to the high density of non-shearableγ-Mg 17 Al 12 nano-precipitates with spherical morphology,which was different from other Mg-Al-based *** results of texture evolution and slip trace analysis demonstrated that the suppression of extension twinning and less basal slip was due to the enhanced activity of pyramidalc+aslip in as-extruded AlN/AZ91 com-posites after peak-aging during the room temperature tension,meanwhile,the dislocation density of as-extruded AlN/AZ91 composites was significantly decreased during peak-aging,then higher elongation to fracture was achieved.

关键词： Magnesium matrix composites Mechanical properties Precipitation Deformation mechanisms Non-basal slip

Federated Learning Security and Privacy-Preserving Algorithm and Experiments Research Under Internet of Things Critical Infrastructure

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Tsinghua science and technology 2024年第2期29卷 400-414页

作者： Nasir Ahmad Jalali Hongsong Chen Department of Computer science University of Science and Technology Beijing(USTB)Beijing 100083China

The widespread use of the Internet of Things(IoTs)and the rapid development of artificial intelligence technologies have enabled applications to cross commercial and industrial band *** such systems,all participants related to commercial and industrial systems must communicate and generate ***,due to the small storage capacities of IoT devices,they are required to store and transfer the generated data to third-party entity called“cloud”,which creates one single point to store their ***,as the number of participants increases,the size of generated data also ***,such a centralized mechanism for data collection and exchange between participants is likely to face numerous challenges in terms of security,privacy,and *** address these challenges,Federated Learning(FL)has been proposed as a reasonable decentralizing approach,in which clients no longer need to transfer and store real data in the central ***,they only share updated training models that are trained over their private *** the same time,FL enables clients in distributed systems to share their machine learning models collaboratively without their training data,thus reducing data privacy and security ***,slow model training and the execution of additional unnecessary communication rounds may hinder FL applications from operating properly in a distributed ***,these unnecessary communication rounds make the system vulnerable to security and privacy issues,because irrelevant model updates are sent between clients and ***,in this work,we propose an algorithm for fully homomorphic encryption called Cheon-Kim-Kim-Song(CKKS)to encrypt model parameters for their local information privacy-preserving *** proposed solution uses the impetus term to speed up model convergence during the model training ***,it establishes a secure communication channel between IoT devices and the *** a

关键词： Federated Learning(FL) Internet of Things(IoTs) lightweight Transport Layer Security(iTLS) Cheon-Kim-Kim-Song(CKKS)