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Nano Research 2024年第4期17卷 2388-2399页

作者： Jing Shao Yusheng Fang Xiaobing Wu Muhammad Imran Abdullah Youkun Tao College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen 518060China School of Science Harbin Institute of TechnologyShenzhen 518055China

The sluggish kinetics of oxygen evolution reaction(OER)is the key tailback for hydrogen production from the water *** OER with thermodynamically auspicious methanol oxidation reaction(MOR)can significantly boost the H_(2) and value-added products ***,it is currently challenging to achieve a synergistic manipulation of product selectivity and performance for MOR ***,we report NiSnPH@OOH/CC(CC=carbon cloth)perovskite hydroxide nanosphere as an efficient MOR electrocatalyst with high activity,stability,and selectivity towards methanol oxidation to formate.A surface amorphous layer of defect rich NiOOH was generated in operando by selective Sn leaching with stable perovskite hydroxide bulk structure,which mitigates the oxidative power and optimizes the local coordination environment of the active NiOOH *** situ Raman combined with electrochemical studies further confirm the key active species,NiOOH,generated in operando enhance the MOR and blocking the over oxidation of methanol to CO_(2).As a result,NiSnPH@OOH/CC effectively masks the OER and attains>99%selectivity with 100%Faradic efficiency for *** results of this study show the advances of NiSnPH@OOH/CC as an efficient electrocatalyst for MOR and also suggest its potential applications for various small organic molecules oxidation.

关键词： perovskite hydroxide small organic molecules nickel oxy(hydroxide) value-added products methanol oxidation reaction

Harpoon-shaped topological photonic crystal for on-chip beam splitter

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Science China(Physics,Mechanics & Astronomy) 2024年第9期Mechanics & Astronomy) .卷 95-102页

作者： Zhiwei Guan Ruixue Dou Chuangxin Xie Tianyimei Zuo Liyu Huang Keyin Wen Chaofeng Wang Huapeng Ye Junmin Liu Ze Dong Dianyuan Fan Shuqing Chen institute of Microscale Optoelectronics Shenzhen University College of Physics and Engineering technology Minzu Normal University of Xingyi Guangdong Provincial Key Laboratory of Optical information Materials and technology and institute of Electronic Paper Displays South China Academy of Advanced OptoelectronicsSouth China Normal University College of New Materials and New Energies Shenzhen Technology University School of information and Electronics Beijing Institute of Technology

The advancement of integrated optical communication networks necessitates the deployment of on-chip beam splitters for efficient signal interconnections at network nodes. However, the pursuit of micron-scale beam splitting with large corners and reducing the device footprint to boost connection flexibility often results in phase mismatches. These mismatches, which stem from radiation modes and backward scattering, pose significant obstacles in creating highly integrated and interference-resistant connections. To address this, we introduce a solution based on the topological valley-contrasting state generated by photonic crystals with opposing valley Chern numbers, manifested in a harpoon-shaped structure designed to steer the splitting *** approach enables adiabatic mode field evolution over large corners, capitalizing on the robust phase modulation capabilities and topological protection provided by the subwavelength-scale valley-contrasting state. Our demonstration reveals that beam splitters with large corners of 60°, 90°, and 120° exhibit insertion loss fluctuations below 2.7 dB while maintaining a minimal footprint of 8.8 μm × 8.8 μm. As a practical demonstration, these devices facilitate three-channel signal connections, successfully transmitting quadrature phase shift keying signals at 3.66 Tbit/s with bit error rates below the forward error correction threshold, demonstrating performance comparable to that in defects scenarios. By harnessing the unidirectional excitation feature, we anticipate significant enhancements in the capabilities of signal distribution and connection networks through a daisy chain configuration.

关键词： channel interconnection on-chip beam splitter topological valley-contrasting state

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Mn-based MXene with high lithium-ion storage capacity

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Nano Research 2024年第5期17卷 4181-4191页

作者： Yanyan Wu Dongqing Liu Xiaonan Wang Usman Ghani Muhammad Asim Mushtaq Jinfeng Yang Huarui Sun Panagiotis Tsiakaras Xingke Cai School of Science and Ministry of Industry and information technology Key Laboratory of Micro-Nano Optoelectronic information System Harbin Institute of Technology ShenzhenShenzhen 5180552 China Collaborative Innovation Center of Extreme Optics Shanxi UniversityTaiyuan 030006China institute for Advanced Study Shenzhen UniversityShenzhen 518060China College of Mechatronics and Control Engineering Shenzhen UniversityShenzhen 518060China Laboratory of Alternative Energy Conversion Systems Department of Mechanical EngineeringSchool of EngineeringUniversity of ThessalyPedion Areos 38834Greece

3d-transition metal(Fe,Co,Ni,and Mn)-based MXene materials have been predicted to demonstrate exceptional electrochemical performance because of their good electrical conductivity and the presence of metallic atoms with multiple charge ***,until now,there have been no reports on MXenes based on Fe,Co,Ni,and Mn,due to the lack of 3d-metal-layered ***,we successfully synthesized the first 3d-transition metal-based MXenes,Mn_(2)CT_(x) by exfoliating a layered precursor derived from the anti-perovskite bulk *** as-prepared Mn_(2)CT_(x) MXene nanosheets were employed as anode materials in lithium-ion batteries,which exhibited stable storage capacity of 764.7 mAh·g^(-1) at 0.5 C,placing its storage capacities at an upper-middle level compared with other reported MXene materials as well as other Mn-based anode ***,this study opens a new avenue for MXene research by synthesizing 3d-transition metal-based MXenes for electrochemical applications.

关键词： Mn_(3)GaC Mn_(2)CT_(x) MXenes lithium-ion battery anode materials negative fading capacity

Recent advances in small-scale hydrogel-based robots for adaptive biomedical applications

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Nano Research 2024年第2期17卷 649-662页

作者： Mingzhe Nie Qilong Zhao Xuemin Du institute of Biomedical&Health Engineering Shenzhen Institute of Advanced Technology(SIAT)Chinese Academy of Sciences(CAS)Shenzhen 518055China

Small-scale robots,ranging in size from micrometers to centimeters,have gained significant attention in the biomedical ***,conventional small-scale robots made of rigid materials encounter challenges in adapting themselves to the soft tissues and complicated environments of human *** to the rigid counterpart,small-scale hydrogel-based robots hold great promises due to their tissue-like low modulus,outstanding biocompatibility and accessible stimuli-responsive *** attributes offer small-scale hydrogel-based robots with multimodal locomotion and reinforced functions,further enhancing the adaptability in manipulation and tasks execution for various biomedical *** this review,we present recent advances in small-scale hydrogel-based *** first summarize the design principles of small-scale hydrogel-based robots including materials,fabrication techniques and manipulation strategies,then highlighting their upgraded functions and adaptive biomedical ***,we discuss existing challenges and future perspectives for small-scale hydrogel-based robots.

关键词： small-scale robot hydrogel locomotion multi-function adaptability

Extending microwave-frequency electric-field detection through single transmission peak method

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Chinese Physics B 2024年第5期33卷 417-423页

作者：刘青陈进湛王赫张杰阮伟民伍国柱郑顺元罗景庭宋振飞 College of Physics and Optoelectronic Engineering Shenzhen UniversityShenzhen 518060China shenzhen institute for technology Innovation National Institute of MetrologyShenzhen 518107China Center for Advanced Measurement Science National Institute of MetrologyBeijing 100029China

The strength of microwave(MW)electric field can be observed with high precision by using the standard electromagnetically induced transparency and Aulter–Towns(EIT-AT)technique,when its frequency is resonant or nearly-resonant with the Rydberg transition *** the detuning of MW field increases,one of the transmission peaks(single peak)is easier to measure due to its increased *** can be found that the central symmetry point of the two transmission peaks f_(1/2)is only related to the detuning of MW field△_(MW)and central symmetry point f_(0)of resonant MW field,satisfying the relation f_(1/2)=△_(MW)/2+f_(0).Thus,we demonstrate a single transmission peak method that the MW E-field can be determined by interval between the position of single peak and f_(1/2).We use this method to measure continuous frequencies in a band from-200 MHz to 200 MHz of the MW *** experimental results and theoretical analysis are presented to describe the effectiveness of this *** 50 MHz<△_(MW)<200 MHz,this method solves the problem that the AT splitting cannot be measured by using the standard EIT-AT techniques or multiple atomic-level Rydberg atom schemes.

关键词： microwave electric field Rydberg atom electromagnetically induced transparency(EIT) Aulter-Towns splitting

Big Data Application Simulation Platform Design for Onboard Distributed Processing of LEO Mega-Constellation Networks

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China Communications 2024年第7期21卷 334-345页

作者： Zhang Zhikai Gu Shushi Zhang Qinyu Xue Jiayin School of Electronics and information Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China Guangdong Provincial Key Laboratory of Aerospace Communication and Networking technology Shenzhen 518055China Broadband Communications Research Department Peng Cheng LaboratoryShenzhen 518000China

Due to the restricted satellite payloads in LEO mega-constellation networks(LMCNs),remote sensing image analysis,online learning and other big data services desirably need onboard distributed processing(OBDP).In existing technologies,the efficiency of big data applications(BDAs)in distributed systems hinges on the stable-state and low-latency links between worker ***,LMCNs with high-dynamic nodes and long-distance links can not provide the above conditions,which makes the performance of OBDP hard to be intuitively *** bridge this gap,a multidimensional simulation platform is indispensable that can simulate the network environment of LMCNs and put BDAs in it for performance *** STK's APIs and parallel computing framework,we achieve real-time simulation for thousands of satellite nodes,which are mapped as application nodes through software defined network(SDN)and container *** elaborate the architecture and mechanism of the simulation platform,and take the Starlink and Hadoop as realistic examples for *** results indicate that LMCNs have dynamic end-to-end latency which fluctuates periodically with the constellation *** to ground data center networks(GDCNs),LMCNs deteriorate the computing and storage job throughput,which can be alleviated by the utilization of erasure codes and data flow scheduling of worker nodes.

关键词： big data application Hadoop LEO mega-constellation multidimensional simulation onboard distributed processing

GraphSTGAN:Situation understanding network of slow-fast high maneuvering targets for maritime monitor services of IoT data

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Digital Communications and Networks 2024年第3期10卷 620-630页

作者： Guanlin Wu Haipeng Wang Yu Liu You He shenzhen International Graduate School Tsinghua UniversityShenzhen518071China institute of Space Science and Applied technology Harbin Institute of TechnologyShenzhen518055China Department of Electronic Engineering Tsinghua UniversityBeijing100084China

With the rapid growth of the maritime Internet of Things(IoT)devices for Maritime Monitor Services(MMS),maritime traffic controllers could not handle a massive amount of data in *** unmanned MMS,one of the key technologies is situation ***,the presence of slow-fast high maneuvering targets and track breakages due to radar blind zones make modeling the dynamics of marine multi-agents difficult,and pose significant challenges to maritime situation *** order to comprehend the situation accurately and thus offer unmanned MMS,it is crucial to model the complex dynamics of multi-agents using IoT big ***,previous methods typically rely on complex assumptions,are plagued by unstructured data,and disregard the interactions between multiple agents and the spatial-temporal correlations.A deep learning model,Graph Spatial-Temporal Generative Adversarial Network(GraphSTGAN),is proposed in this paper,which uses graph neural network to model unstructured data and uses STGAN to learn the spatial-temporal dependencies and *** experiments show the effectiveness and robustness of the proposed method.

关键词： Internet of things Multi-agents Graph neural network Maritime monitoring services

Lattice Boltzmann simulation study of anode degradation in solid oxide fuel cells during the initial aging process

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International Journal of Minerals,Metallurgy and Materials 2024年第2期31卷 405-411页

作者： Shixue Liu Zhijing Liu Shuxing Zhang Hao Wu Hydrogen Energy Industrial technology Innovation Center China Nuclear Power Technology Research InstituteShenzhen 518031China shenzhen Engineering Research Center for Hydrogen Safety Shenzhen 518031China

For present solid oxide fuel cells(SOFCs),rapid performance degradation is observed in the initial aging process,and the dis-cussion of the degradation mechanism necessitates quantitative ***,focused ion beam-scanning electron microscopy was em-ployed to characterize and reconstruct the ceramic microstructures of SOFC *** lattice Boltzmann method(LBM)simulation of multiphysical and electrochemical processes in the reconstructed models was *** samples collected from industrial-size cells were characterized,including a reduced reference cell and a cell with an initial aging *** parameters of the reconstructed microstructures revealed a significant decrease in the active triple-phase boundary and Ni connectivity in the aged cell compared with the reference *** LBM simulation revealed that activity degradation is dominant compared with microstructural degradation during the initial aging process,and the electrochemical reactions spread to the support layer in the aged *** microstructural and activity de-gradations are attributed to Ni migration and coarsening.

关键词： solid oxide fuel cell anode degradation focused ion beam-scanning electron microscopy lattice Boltzmann method

Efflcient machining of a complex blisk channel using a disc cutter

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Chinese Journal of Aeronautics 2024年第1期37卷 414-437页

作者： Xiangyu LI Zhaoyu LI Dong HE Junxue REN Qian FENG Kai TANG Department of Mechanical and Aerospace Engineering Hong Kong University of Science and TechnologyHong Kong 999077China Key Laboratory of High Performance Manufacturing for Aero Engine(Northwestern Polytechnical University) Ministry of Industry and Information TechnologyXi’an 710072China Xi’an Sanhang Power technology Co. LtdXi’an 710000China HKUST shenzhen-Hong Kong Collaborative Innovation Research institute FutianShenzhen 518057China HKUST shenzhen Research institute Shenzhen 518057China

For rough machining of a complex narrow cavity,e.g.,a complex blisk channel on an aero-engine,the typically used cutting tools are the slender cylindrical cutter and conical ***,as neither of the two is particularly suited for rough machining,wherein the main purpose is to remove a large volume as quickly as possible,the machining efficiency is low,especially when the part materials are of hard-to-cut types(e.g.,Titanium-alloy)for which it often takes days to rough machine a ***,disc machining provides a new and efficient roughing solution,since a disc cutter with a large radius enables a much larger cutting speed and thus a larger material removal ***,due to the large radius of the disc cutter,its potential collision with narrow and twisted channels becomes a serious *** this paper,we propose a novel twophase approach for efficiently machining a complex narrow cavity workpiece using a disc-shaped cutter,i.e.,3+2-axis disc-slotting of the channel by multiple layers(rough machining)+five-axis disc-milling of the freeform channel side surfaces(semi-finish machining).Both simulation and physical cutting experiments are conducted to assess the effectiveness and advantages of the proposed *** experimental results show that,with respect to a same cusp-height threshold on the channel side surfaces,the total machining time of the tested part by the proposed method is about only 36%of that by the conventional approach of plunging-milling(for roughing)plus milling by a slender cylindrical cutter(for semi-finishing).

关键词： Blisk channel CNC machining Disc cutter Roughing efficiency Tool path planning

Multilevel carbon architecture of subnanoscopic silicon for fast‐charging high‐energy‐density lithium‐ion batteries

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Carbon Energy 2024年第4期6卷 256-268页

作者： Meisheng Han Yongbiao Mu Lei Wei Lin Zeng Tianshou Zhao shenzhen Key Laboratory of Advanced Energy Storage Southern University of Science and TechnologyShenzhenChina SUSTech Energy institute for Carbon Neutrality Southern University of Science and TechnologyShenzhenChina Department of Mechanical and Energy Engineering Southern University of Science and TechnologyShenzhenChina

Silicon(Si)is widely used as a lithium‐ion‐battery anode owing to its high capacity and abundant crustal ***,large volume change upon cycling and poor conductivity of Si cause rapid capacity decay and poor fast‐charging capability limiting its commercial ***,we propose a multilevel carbon architecture with vertical graphene sheets(VGSs)grown on surfaces of subnanoscopically and homogeneously dispersed Si–C composite nanospheres,which are subsequently embedded into a carbon matrix(C/VGSs@Si–C).Subnanoscopic C in the Si–C nanospheres,VGSs,and carbon matrix form a three‐dimensional conductive and robust network,which significantly improves the conductivity and suppresses the volume expansion of Si,thereby boosting charge transport and improving electrode *** VGSs with vast exposed edges considerably increase the contact area with the carbon matrix and supply directional transport channels through the entire material,which boosts charge *** carbon matrix encapsulates VGSs@Si–C to decrease the specific surface area and increase tap density,thus yielding high first Coulombic efficiency and electrode compaction ***,C/VGSs@Si–C delivers excellent Li‐ion storage performances under industrial electrode *** particular,the full cells show high energy densities of 603.5 Wh kg^(−1)and 1685.5 Wh L^(−1)at 0.1 C and maintain 80.7%of the energy density at 3 C.

关键词： fast charging high energy densities lithium‐ion batteries multilevel carbon architecture subnanoscopic silicon anode