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Nuclear Science and Techniques 2024年第1期35卷 1-9页

作者： Chen-Hui Cui zi-mu zhou Lin-Feng Wei Song-Lin Li Feng Tian Xiu-Hong Li Zhi Guo Yi-Hui Xu Huai-Dong Jiang Ren-Zhong Tai Shanghai Synchrotron Radiation Facility Shanghai Advanced Research InstituteChinese Academy of SciencesShanghai 201204China School of Physical Science and Technology ShanghaiTech UniversityShanghai 201210China Shanghai Institute of Applied Physics Chinese Academy of SciencesShanghai 201800China University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100049China Center for Transformative Science ShanghaiTech UniversityShanghai 201210China

X-ray photon correlation spectroscopy(XPCS)has emerged as a powerful tool for probing the nanoscale dynamics of soft condensed matter and strongly correlated materials owing to its high spatial resolution and penetration *** technique requires high brilliance and beam coherence,which are not directly available at modern synchrotron beamlines in *** facilitate future XPCS experiments,we modified the optical setup of the newly commissioned BL10U1 USAXS beamline at the Shanghai Synchrotron Radiation Facility(SSRF).Subsequently,we performed XPCS measurements on silica suspensions in glycerol,which were opaque owing to their high *** were collected using a high frame rate area detector.A comprehensive analysis was performed,yielding correlation functions and several key dynamic *** the results were consistent with the theory of Brownian motion and demonstrated the feasibility of XPCS at ***,by carefully optimizing the setup and analyzing the algorithms,we achieved a time resolution of 2 ms,which enabled the characterization of millisecond dynamics in opaque systems.

关键词： XPCS SSRF Silica suspension Glycerol Brownian motion Millisecond dynamics

Reliable calculations of nuclear binding energies by the Gaussian process of machine learning

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Nuclear Science and Techniques 2024年第6期35卷 130-144页

作者： zi-Yi Yuan Dong Bai Zhen Wang Zhong-zhou Ren School of Physics Science and Engineering Tongji UniversityShanghai 200092China College of Science Hohai UniversityNanjing 211100China Key Laboratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China

Reliable calculations of nuclear binding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical problems. In this study, the nuclear binding energies are modeled directly using a machine-learning method called the Gaussian process. First, the binding energies for 2238 nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ability of the Gaussian process in the studies of binding energies. Then, the predictive power of the Gaussian process is studied by calculating the binding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical binding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeably, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett B 834, 137484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliable for the calculations of nuclear binding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can be useful guides for future research on binding energies and α-decay properties.

关键词： Nuclear binding energies decay Machine learning Gaussian process

Hot Compression Behavior and Tensile Property of a Novel Ni-Co-Based Superalloy Prepared by Electron Beam Smelting Layered Solidification Technology

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Acta Metallurgica Sinica(English Letters) 2024年第2期37卷 283-292页

作者： Yong-Chao Gai Rui Zhang Chuan-Yong Cui zi-Jian zhou Yi Tan Yi-zhou zhou Xiao-Feng Sun Key Laboratory of Materials Modification by Laser Ionand Electron Beams(Ministry of Education)School of Materials Science and EngineeringDalian University of TechnologyDalian116024China Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China

The hot compression behavior and tensile strength after compression of a new Ni-Co-based superalloy produced using electron beam smelting layered(EBSL)solidification technology were *** compression tests were performed at temperatures of 1120℃and 1150℃,with strain rates of 1 s^(-1) and 0.01 s^(-1),reaching a true strain of *** strength was evaluated at room *** results revealed that this EBSL technology accelerates dynamic recrystallization(DRX),without compromising the strength of alloy.A significant correlation between the volume fraction of DRX and the strain rate was observed,with higher fractions at lower strain rates,leading to higher tensile ***,at the same strain rate,the specimens compressed at 1120℃exhibited higher tensile strength due to undissolvedγ′*** solution and aging heat treatment,the alloy maintained high tensile *** results suggested that the EBSL Ni-Co-based superalloy offers excellent prospects for practical applications.

关键词： Ni-Co-based superalloy Hot deformation Electron beam smelting Tensile strength

Constructing oxygen deficiency-rich V_(2)O_(3)@PEDOT cathode for high-performance aqueous zinc-ion batteries

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Rare Metals 2024年第2期43卷 635-646页

作者： Dong-Fei Sun zi-Juan Wang Tian Tian Xin Yu Dan-Dan Yu Xiao-Zhong zhou Guo-Fu Ma zi-Qiang Lei Key Laboratory of Eco-functional Polymer Materials of the Ministry of Education Key Laboratory of Eco-environmental Polymer Materials of Gansu ProvinceSchool of College of Chemistry and Chemical EngineeringNorthwest Normal UniversityLanzhou730070China

Aqueous zinc-ion batteries(AziBs)have attracted widespread attention due to the advantages of high safety and environmental *** V_(2)O_(3) is a promising cathode,the strong electrostatic interaction between Zn^(2+) and V_(2)O_(3) crystal,and the sluggish reaction kinetics still limit their application in ***,the oxygen defects rich V_(2)O_(3) with conducive poly(3,4-ethylenedioxythiophene)(PEDOT)shell(V_(2)O_(3)-Od@PEDOT)was fabricated for AziBs by combining the sulfur-assisted thermal reduction and in-situ polymerization *** introduced oxygen vacancies of V_(2)O_(3)–Od@PEDOT weaken the electrostatic interaction between Zn^(2+) and the host material,improving the interfacial electron transport,while the PEDOT coating enhances the structural stability and conductivity of V_(2)O_(3),thus accelerating the reaction *** on the advantages,V_(2)O_(3)–Od@PEDOT electrode delivers a reversible capacity of 495 mAh·g^(−1) at 0.1 A·g^(−1),good rate capability(189 mAh·g^(−1)at 8.0 A·g^(−1)),and an impressive cycling stability with 90.1%capacity retention over 1000 cycles at 8.0 A·g^(−1).The strategy may provide a path for exploiting the other materials for high performance AziBs.

关键词： Oxygen defects V_(2)O_(3) PEDOT Electrochemical self-optimization Aqueous zinc-ion batteries

Reinfection and Risk Factors of SARS-CoV-2 during an Omicron Wave 2022 in Shanghai

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Biomedical and Environmental Sciences 2024年第2期37卷 204-209页

作者： WANG Pei Qin WANG Xiao Hang WANG Jian SHI Zhi Wen CHU Dong Mei WANG Zhi Fei ZHANG mu Bai LIU Wei zhou zi Jie XIE Wei Fen Department of Gastroenterology Changzheng HospitalNaval Medical UniversityShanghai 200003China Health examination center Changzheng HospitalNaval Medical UniversityShanghai 200003China

multiple waves of coronavirus disease 2019(COVID-19) outbreaks have affected numerous countries worldwide. The first case of SARS-CoV-2 reinfection was reported in Hong Kong in August 2020^([1]), leading to increased interest in the effectiveness of natural immunity acquired from primary infection. While data reports vary across countries, all findings indicate that prior SARS-CoV-2 infection provides substantial protection against reinfection^([2]). However, natural immunity from infection with previous non-Omicron or early Omicron sub-lineages offers lower levels of protection against Omicron reinfection, with rates below 60%^([3]) and approximately 75%[4], respectively.

关键词： immunity infection Omi

Realizing high initial Coulombic efficiency in manganese-based layered oxide cathodes for sodium-ion batteries via P2/O'3 biphasic structure optimization

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Rare Metals 2024年第5期43卷 2093-2102页

作者： Bo Peng zi-Hao zhou Ping Xuan Jie Xu Lian-Bo Ma School of Materials Science and Engineering Anhui University ofTechnologyMa'anshan 243002China Anhui Product Quality Supervision&Inspection Research Institute Hefei 230051China

Mn-based layered oxides are among the most promising cathode materials for sodium-ion batteries owing to the advantages of abundance,environmenta friendliness,low cost and high specific capacity.P2 and O'3 are two representative structures of Mn-based layered ***,the P2 structure containing insufficien Na generally exhibits low initial charge capacity,while O'3structure with sufficient Na delivers high initial charge capacity but poor cycle *** study prepared a multitude of Na_(x)MnO_(2)(x=0.7,0.8,0.9)cathode materials with varying P2/O'3 ratios and further investigated their electrochemical *** optimized Na_(0.8)MnO_(2) comprising 69.9 wt%O'3 and 30.1 wt%P2 phase,exhibited relatively balanced specific capacity,Coulombic efficiency and cycle ***,it achieved a high specific capacity of 128.9 mAh·g^(-1) with an initia Coulombic efficiency of 98.2%in half-cell configuration The Na_(0.8)MnO_(2)//hard carbon full cell also achieved a high specific capacity of 126.7 mAh·g^(-1) with an initia Coulombic efficiency of 98.9%.Moreover,the capacity fading mechanism was revealed by combining in-situ and ex-situ X-ray *** findings of this study provide theoretical guidance for further modification design of Mnbased layered cathodes.

关键词： Sodium-ion batteries Cathode materials Mn-based layered oxides P2/0'3 composites

Hydrophobic long-chain two-dimensional perovskite scintillators for underwater X-ray imaging

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Rare Metals 2024年第1期43卷 175-185页

作者： Jin-Xiao Zheng zi-An zhou Tiao Feng Hui Li Cheng-Hua Sun NüWang Yang Tian Yong Zhao Shu-Yun zhou Key Laboratory of Photochemical Conversion and Optoelectronic Materials Technical Institute of Physics and ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China Laboratory of Bioinspired Smart Interfacial Science and Technology of the Ministry of Education Beijing Key Laboratory of Bioinspired Energy Materials and DevicesSchool of ChemistryBeijing Advanced Innovation Center for Biomedical EngineeringBeihang UniversityBeijing 100191China Department of Engineering Physics Tsinghua University and Key Laboratory of Particle and Radiation Imaging Ministry of EducationTsinghua UniversityBeijing 100084China e-mail:yangt@***

The underwater X-ray imaging technology development is significant to subaqueous target reconnaissance/detection/identification, subfluvial archaeology,submerged resource exploration, etc. As the core of X-ray imaging detection, the scintillator has been plagued by inherent moisture absorption and decomposition, and strict requirements for seamless packaging and ***, we designed a manganese-doped two-dimensional(2D) perovskite scintillator modified by hydrophobic longchain organic amine through the combination of component and doping engineering. The modified perovskites show high water repellency that can be used as an underwater X-ray scintillator. X-ray images of aquatic organisms or other objects with a high spatial resolution of10 lp·mm^(-1) at a big view field(32 mm × 32 mm) were obtained by scintillation screen. This hydrophobic perovskite scintillator based on molecular design is of great promise in underwater X-ray nondestructive testing technology development.

关键词： Two-dimensional perovskite Hydrophobic Scintillators Underwater X-ray imaging Underwater nondestructive testing technology

Astronomical Test with CMOS on the 60 cm Telescope at the Xinglong Observatory,NAOC

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Research in Astronomy and Astrophysics 2024年第5期24卷 85-102页

作者： Hai-Yang mu zhou Fan Yi-Nan Zhu Yu Zhang Hong Wu Key Laboratory of Optical Astronomy National Astronomical ObservatoriesChinese Academy of SciencesBeijing 100101People’s Republic of China School of Astronomy and Space Science University of Chinese Academy of SciencesBeijing 100049People’s Republic of China

This work shows details of an evaluation of an observational system comprising a complementary metal-oxidesemiconductor detector, 60 cm telescope and filter complement. The system’s photometric precision and differential photometric precision, and extinction coefficients were assessed through observations of Supersky flat fields, open clusters, standard stars and exoplanets. Photometry was precision achieved at the 0.02 mag level, with differential photometry of 0.004 mag precision. Extinction was found to agree with previous studies conducted at Xinglong Observatory. Ultimately, the results demonstrate this observing system is capable of precision scientific observations with a charge-coupled device across the optical wavelengths.

关键词： atmospheric effects-instrumentation detectors-techniques polarimetric-stars atmospheres-eclipses

Improved YOLOv8n Model for Detecting Helmets and License Plates on Electric Bicycles

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Computers, Materials & Continua 2024年第7期80卷 449-466页

作者： Qunyue mu Qiancheng Yu Chengchen zhou Lei Liu Xulong Yu The College of Computer Science and Engineering North Minzu UniversityYinchuan750021China The Key Laboratory of Images and Graphics Intelligent Processing of State Ethnic Affairs Commission North Minzu UniversityYinchuan750021China

Wearing helmetswhile riding electric bicycles can significantly reduce head injuries resulting fromtraffic *** effectively monitor compliance,the utilization of target detection algorithms through traffic cameras plays a vital role in identifying helmet usage by electric bicycle riders and recognizing license plates on electric ***,manual enforcement by traffic police is time-consuming and *** methods face challenges in accurately identifying small targets such as helmets and license plates using deep learning *** paper proposes an enhanced model for detecting helmets and license plates on electric bicycles,addressing these *** proposedmodel improves uponYOLOv8n by deepening the network structure,incorporating weighted connections,and introducing lightweight convolutional *** modifications aim to enhance the precision of small target recognition while reducing the model’s parameters,making it suitable for deployment on low-performance devices in real traffic *** results demonstrate that the model achieves an mAP@0.5 of 91.8%,showing an 11.5%improvement over the baselinemodel,with a 16.2%reduction in ***,themodel achieves a frames per second(FPS)rate of 58,meeting the accuracy and speed requirements for detection in actual traffic scenarios.

关键词： YOLOv8 object detection electric bicycle helmet detection electric bicycle license plate detection

Cracking on a nickel-based superalloy fabricated by direct energy deposition

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China Foundry 2024年第4期21卷 311-318页

作者： Xue Zhang Ya-hang mu Liang Ma Jing-jing Liang Yi-zhou zhou Xiao-feng Sun Jin-guo Li School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Shi-changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering Northeastern UniversityShenyang 110819China

Cracks have consistently been a significant challenge limiting the development of additive manufactured nickel-based *** is essential to investigate the location of cracks and their forming *** study extensively examines the impact of solidification process,microstructural evolution,and stress concentration on crack initiation during direct energy deposition(DED).The results emphasize that the crack formation is significantly related to large-angle grain boundaries,rapid cooling *** caused by large-angle grain boundaries and a fast-cooling rate predominantly appear near the edge of the deposited *** cracks are more likely to form near the top of the deposited sample,due to the presence ofγ/γ'*** secondary dendritic arm and the carbides in the interdendritic regions can obstruct liquid flow during the final stage of solidification,which results in the formation of solidification cracks and *** work paves the way to avoid cracks in nickel-based superalloys fabricated by DED,thereby enhancing the performance of superalloys.

关键词： location cracks direct energy deposition nickel-based superalloys