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Chinese Journal of Mechanical Engineering 2024年第1期37卷 203-214页

作者： Xiaokang Huang Xiaoyong Tian Qi Zhong Shunwen He Cunbao Huo Yi Cao Zhiqiang Tong Dichen Li State Key Laboratory of Manufacturing Systems Engineering Xi’an Jiaotong UniversityXian 710049China

Improvement of fabrication efficiency and part performance was the main challenge for the large-scale powder bed fusion(PBF)*** this study,a dynamic monitoring and feedback system of powder bed temperature field using an infrared thermal imager has been established and integrated into a four-laser PBF equipment with a working area of 2000 mm×2000 *** heat-affected zone(HAZ)temperature field has been controlled by adjusting the scanning speed ***,the relationship among spot size,HAZ temperature,and part performance has been *** fluctuation of the HAZ temperature in four-laser scanning areas was decreased from 30.85℃to 17.41℃.Thus,the consistency of the sintering performance of the produced large component has been *** on the controllable temperature field,a dynamically adjusting strategy for laser spot size was proposed,by which the fabrication efficiency was improved up to 65.38%.The current research results were of great significance to the further industrial applications of large-scale PBF equipment.

关键词： Powder bed fusion Efficiency Large-scale Spot size Heat-affected zone(HAZ)

Picotesla fiberized diamond-based AC magnetometer

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Photonics Research 2024年第6期12卷 1250-1261页

作者： SHAO-CHUN ZHANG YONG LIU LONG-KUN SHAN XUE-DONG GAO JIA-QI GENG CUI YU YANG DONG XIANG-DONG CHEN GUANG-CAN GUO FANG-WEN SUN CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China national Key Laboratory of ASIC Hebei Semiconductor Research InstituteShijiazhuang 050051China Electric Power Quantum Sensing Joint Laboratory of Anhui Province State Grid Anhui Electric Power Research InstituteHefei 230601China Hefei national Laboratory University of Science and Technology of ChinaHefei 230088China

Portable quantum sensors are crucial for developing practical quantum sensing and metrology *** nitrogen-vacancy(NV)centers in diamonds have emerged as one of the most promising candidates for compact quantum ***,due to the difficulty of coherently controlling the ensemble spin and noise suppression in a large volume,it often faces problems such as reduced sensitivity and narrowed bandwidth in integrated lensless ***,we propose a fluorescence signal treatment method for NV spin ensemble manipulation by the exponential fitting of spin polarization processes,instead of integrating the photon *** enables spin state readout with a high signal-to-noise ratio and applies to the pulse sensing protocols for large-volume NV *** on this,we further developed a fiberized diamond-based AC *** an XY8-N dynamical decoupling pulse sequence,we demonstrated a T_(2)-limited sensitivity of 8pT/√Hz and T_(1)-limited frequency resolution of 90 Hz over a wide frequency band from 100 kHz to 3 *** integrated diamond sensor leverages quantum coherence to achieve enhanced sensitivity in detecting AC magnetic fields,making it suitable for implementation in a compact and portable endoscopic sensor.

关键词： magnetometer quantum ensemble

Electronic structures and Mott state of epitaxial TaS_(2) monolayers

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Science china(Physics,Mechanics & Astronomy) 2024年第5期67卷 91-97页

作者： Qichao Tian Chi Ding Xiaodong Qiu Qinghao Meng Kaili Wang Fan Yu Yuyang Mu Can Wang Jian Sun Yi Zhang national Laboratory of Solid State Microstructure School of PhysicsNanjing UniversityNanjing 20093China Collaborative Innovation Center of Advanced Microstructures Nanjing UniversityNanjing 210093China School of Physics and Electronic Sciences Changsha University of Science and TechnologyChangsha 410114China Hefei national Laboratory Hefei 230088China

Layered material TaS2hosts multiple structural phases and exotic correlated quantum states,including charge density wave(CDW),superconductivity,quantum spin liquid,and Mott insulating ***,we synthesized TaS_(2)monolayers in H and T phases using the molecular beam epitaxial(MBE)method and studied their electronic structures via angle-resolved photoemission spectroscopy(ARPES).We found that the H phase TaS_(2)(H-TaS_(2))monolayer is metallic,with an energy band crossing the Fermi *** contrast,the T phase TaS_(2)(T-TaS_(2))monolayer shows an insulated energy gap at the Fermi level,while the normal calculated band structure implies it should be metallic without any band ***,by considering Hubbard interaction potential U,further density functional theory(DFT)calculation suggests that monolayer T-TaS_(2)could be a CDW Mott insulator,and the DFT+U calculation matches well with the ARPES *** significantly,the temperature-dependent ARPES result indicates that the CDW Mott state in the T-TaS_(2)monolayer is more robust than its bulk counterpart and can persist at room *** results reveal that the dimensional effect can enhance the CDW Mott state and provide valuable insights for further exploring the exotic properties of monolayer TaS2.

关键词： temperature monolayer state

Effective Activation of Melamine for Synchronous Synthesis of Catalytically Active Nanosheets and Fluorescence-Responsive Quantum Dots

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Transactions of Tianjin University 2024年第3期30卷 284-296页

作者： Jie Xuan Guijian Guan Ming-Yong Han Institute of Molecular Plus Tianjin UniversityTianjin 300072China

Because of the low reactivity of cyclic nitrides,liquid-phase synthesis of carbon nitride introduces challenges despite its favorable potential for energy-efficient preparation and superior *** this study,we demonstrate a strong interaction between citric acid and melamine through experimental observation and theoretical simulation,which eff ectively activates melamine-condensation activity and produces carbon-rich carbon nitride nanosheets(CCN NSs)during hydrothermal *** a large specific surface area and increased light absorption,these CCN NSs demonstrate significantly enhanced photocatalytic activity in CO_(2) reduction,increasing the CO production rate by approximately tenfold compared with hexagonal melamine(h-Me).Moreover,the product selectivity of CCN NSs reaches up to 93.5%to generate CO from CO_(2).Furthermore,the annealed CCN NSs exhibit a CO conversion rate of up to 95.30μmol/(g h),which indicates an 18-fold increase compared with traditional carbon *** the CCN NS synthesis,nitrogen-doped carbon quantum dots(NDC QDs)are simultaneously produced and remain suspended in the supernatant after *** QDs disperse well in water and exhibit excellent luminescent properties(QY=67.2%),allowing their application in the design of selective and sensitive sensors to detect pollutants such as pesticide 2,4-dichlorophenol with a detection limit of as low as 0.04μmol/***,the simultaneous synthesis of CCN NSs and NDC QDs provides a cost-eff ective and highly efficient process,yielding products with superior capabilities for catalytic conversion of CO_(2) and pollutant detection,respectively.

关键词： Carbon nitride Hydrothermal reaction Photocatalysis Carbon dioxide Quantum dots

A Distortion Self-Calibration Method for Binocular high Dynamic Light Adjusting and Imaging System Based on Digital Micromirror Device

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IEEE/CAA Journal of Automatica Sinica 2024年第9期11卷 2036-2038页

作者： Pei Wu Yanjie Wang Honghai Sun Zhuoman Wen University of Chinese Academy of Sciences Beijing 100049and NIO Inc.Shanghai 200000China Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China

Dear Editor,In order to realize the pixel level light adjusting control of the binocular high dynamic light adjusting and imaging system, this letter proposed a novel self-calibration method. By analyzing the optical design of the system, the causes of the distortion are given and a distortion model is established. Then, a quick and accurate self-calibration method is designed. The experiments indicate that the method can calibrate the two image sensors of the system at the same time,the average pixel deviation of the calibrated system is less than 0.5pixels and the maximum deviation is less than 1 pixel.

关键词： Dynamic system deviation

Downscaling Seasonal Precipitation Forecasts over East Africa with Deep Convolutional Neural Networks

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Advances in Atmospheric Sciences 2024年第3期41卷 449-464页

作者： Temesgen Gebremariam ASFAW Jing-Jia LUO Institute for Climate and Application Research(ICAR)/CIC-FEMD/KLME/ILCEC Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Geophysics Space Science and Astronomy Addis Ababa UniversityAddis Ababa 1176Ethiopia

This study assesses the suitability of convolutional neural networks(CNNs) for downscaling precipitation over East Africa in the context of seasonal forecasting. To achieve this, we design a set of experiments that compare different CNN configurations and deployed the best-performing architecture to downscale one-month lead seasonal forecasts of June–July–August–September(JJAS) precipitation from the Nanjing University of Information Science and technology Climate Forecast System version 1.0(NUIST-CFS1.0) for 1982–2020. We also perform hyper-parameter optimization and introduce predictors over a larger area to include information about the main large-scale circulations that drive precipitation over the East Africa region, which improves the downscaling results. Finally, we validate the raw model and downscaled forecasts in terms of both deterministic and probabilistic verification metrics, as well as their ability to reproduce the observed precipitation extreme and spell indicator indices. The results show that the CNN-based downscaling consistently improves the raw model forecasts, with lower bias and more accurate representations of the observed mean and extreme precipitation spatial patterns. Besides, CNN-based downscaling yields a much more accurate forecast of extreme and spell indicators and reduces the significant relative biases exhibited by the raw model predictions. Moreover, our results show that CNN-based downscaling yields better skill scores than the raw model forecasts over most portions of East Africa. The results demonstrate the potential usefulness of CNN in downscaling seasonal precipitation predictions over East Africa,particularly in providing improved forecast products which are essential for end users.

关键词： East Africa seasonal precipitation forecasting downscaling deep learning convolutional neural networks(CNNs)

Two-Staged Method for Ice Channel Identification Based on Image Segmentation and Corner Point Regression

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china Ocean Engineering 2024年第2期38卷 313-325页

作者： DONG Wen-bo ZHOU Li DING Shi-feng WANG Ai-ming CAI Jin-yan School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212003China School of Naval Architecture Ocean and Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China

Identification of the ice channel is the basic technology for developing intelligent ships in ice-covered waters,which is important to ensure the safety and economy of *** the Arctic,merchant ships with low ice class often navigate in channels opened up by *** in the ice channel often depends on good maneuverability skills and abundant experience from the captain to a large *** ship may get stuck if steered into ice fields off the *** this circumstance,it is very important to study how to identify the boundary lines of ice channels with a reliable *** this paper,a two-staged ice channel identification method is developed based on image segmentation and corner point *** first stage employs the image segmentation method to extract channel *** the second stage,an intelligent corner regression network is proposed to extract the channel boundary lines from the channel region.A non-intelligent angle-based filtering and clustering method is proposed and compared with corner point regression *** training and evaluation of the segmentation method and corner regression network are carried out on the synthetic and real ice channel *** evaluation results show that the accuracy of the method using the corner point regression network in the second stage is achieved as high as 73.33%on the synthetic ice channel dataset and 70.66%on the real ice channel dataset,and the processing speed can reach up to 14.58frames per second.

关键词： ice channel ship navigation identification image segmentation corner point regression

Ultrathin surface coating of Cu enabling long-life Zn metal anodes

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Rare Metals 2024年第5期43卷 2125-2135页

作者： Sang-Sang Liu Ya-Ru Liang Wen-Long Chen Ze-Hua Wang Yi-Long Dai Fu-Gang Qi Zeng-Sheng Ma Xiao-Ping Ouyang School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Key Laboratory of Low Dimensional Materials and Application technology of Ministry of Education Xiangtan UniversityXiangtan 411105China

Aqueous zinc-ion batteries(AZIBs)are regarded as promising energy storage devices due to their low cost,high capacity,and ecological ***,the severe dendritic growth and side reactions hinder their practical applicability ***,an ultrathin Cu coating layer(~200 nm)is decorated on zinc foils via filtered cathodic vacuum arc deposition technology,aiming to achieve high-performance *** Cu layer effectively suppresses chemical corrosion and hydrogen evolution reactions and enables preferential(002)Zn deposition during the stripping/plating ***,the Cu@Zn anode represents an elongated cycle life over 4,000 h at 2 mA·cm^(-2)/2 mAh·cm^(-2).Even in conditions of high current density of 5 and 10 mA·cm^(-2),the Cu@Zn anode shows prolonged cycling stability exceeding 4000 and 2000 h,*** advantages also bring high Coulombic efficiency of 99.87%under 5 mAh·cm^(-2)in Cu@Ti||Zn half-cell over 1500 ***,the Cu@Zn||MnO_(2)full cell demonstrates a superior cyclability with a specific capacity of 203 mAh·g^(-1)after 500 cycles a1 A·g^(-1).

关键词： Zn ion battery Zn metal anode Zn(002)plane Cu coating

Coordination-environment regulation of atomic Co-Mn dual-sites for efficient oxygen reduction reaction

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Nano Research 2024年第8期17卷 6841-6848页

作者： Caiting Sun Yarong Liu Zunhang Lv Rui Liu Changli Wang Liuhua Li Jinming Wang Yu Zhang Wenxiu Yang Bo Wang Key Laboratory of Cluster Science(Ministry of Education) Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion MaterialsAdvanced Technology Research Institute(Jinan)Advanced Research Institute of Multidisciplinary ScienceSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing Institute of technology Library Beijing Institute of TechnologyBeijing 100081China

Precisely designing atomic metal-nitrogen-carbon(M-N-C)catalysts with asymmetric diatomic configurations and studying their structure–activity relationships for oxygen reduction reaction(ORR)are important for zinc-air batteries(ZABs).Herein,a dualatomic-site catalyst(DASC)with CoN_(3)S-MnN_(2)S_(2)configuration was prepared for the cathodes of *** with Co-N-C(Mn-free)and CoMn-N-C(S-free doping),CoMn-N/S-C exhibits excellent half-wave potential(0.883 V)and turnover frequency(1.54 e·s^(−1)·site^(−1)),surpassing most of the reported state-of-the-art Pt-free ORR *** CoMn-N/S-C-based ZABs achieve extremely high specific capacity(959 mAh·g^(−1))and good stability(350 h@5 mA·cm^(−2)).Density functional theory(DFT)calculation shows that the introduction of Mn and S can break the electron configuration symmetry of the original Co 3d orbital,lower the dband center of the Co site,and optimize the desorption behavior of*OH intermediate,thereby increasing the ORR activity.

关键词： metal organic frameworks oxygen reduction reaction dual-atom catalyst coordination-environment regulation zinc-air batteries

Metal nanoparticles for cancer therapy:Precision targeting of DNA damage

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Acta Pharmaceutica Sinica B 2024年第3期14卷 1132-1149页

作者： Qian Chen Chunyan Fang Fan Xia Qiyue Wang Fangyuan Li Daishun Ling Institute of Pharmaceutics Hangzhou Institute of Innovative MedicineCollege of Pharmaceutical SciencesZhejiang UniversityHangzhou 310058China Frontiers Science Center for Transformative Molecules School of Chemistry and Chemical EngineeringNational Center for Translational MedicineShanghai Jiao Tong UniversityShanghai 200240China World Laureates Association(WLA)Laboratories Shanghai 201203China Key Laboratory of Precision Diagnosis and Treatment for Hepatobiliary and Pancreatic Tumor of Zhejiang Province Hangzhou 310009China

Cancer,a complex and heterogeneous disease,arises from genomic ***,DNA damage-based cancer treatments,including radiotherapy and chemotherapy,are employed in clinical ***,the efficacy and safety of these therapies are constrained by various factors,limiting their ability to meet current clinical *** nanoparticles present promising avenues for enhancing each critical aspect of DNA damage-based cancer *** customizable physicochemical properties enable the development of targeted and personalized treatment *** this review,we delve into the design principles and optimization strategies of metal *** shed light on the limitations of DNA damage-based therapy while highlighting the diverse strategies made possible by metal *** encompass targeted drug delivery,inhibition of DNA repair mechanisms,induction of cell death,and the cascading immune ***,we explore the pivotal role of physicochemical factors such as nanoparticle size,stimuli-responsiveness,and surface modification in shaping metal nanoparticle ***,we present insights into the challenges and future directions of metal nanoparticles in advancing DNA damage-based cancer therapy,paving the way for novel treatment paradigms.

关键词： DNA damage Metal nanoparticles Nucleus-targeting DNA repair inhibition Immune response Size optimization Stimuli-responsiveness Surface modification