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GNPs含量对Al-Si-Cu合金的摩擦磨损性能的影响

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轻金属 2021年第10期 54-58页

作者：潘绪全徐冬张波宋宝成江苏安全技术职业学院机械工程学院江苏徐州221000

在本研究中,利用金相显微镜(OM),扫描电子显微镜(SEM),能谱分析仪(EDS),显微硬度计和摩擦磨损试验机对GNPs(石墨烯片)/Al-Si-Cu复合材料的显微组织、显微硬度和摩擦磨损性能等进行了分析和表征。研究结果表明:随着GNPs的含量的逐渐增加... 详细信息

在本研究中,利用金相显微镜(OM),扫描电子显微镜(SEM),能谱分析仪(EDS),显微硬度计和摩擦磨损试验机对GNPs(石墨烯片)/Al-Si-Cu复合材料的显微组织、显微硬度和摩擦磨损性能等进行了分析和表征。研究结果表明:随着GNPs的含量的逐渐增加,磨损率和摩擦系数均呈现出先减小再增大的趋势。当GNPs的含量为12 vol.%时,复合材料中的Si相明显得到了细化,由基体合金的长条状变为复合材料的短棒状。此时复合材料的磨损率和摩擦系数均最小,分别为21.27×10^(-3) mm^(3)/m和0.358,与Al-Si-Cu基体合金相比分别降低了37.07%和15.76%,复合材料的耐磨性能达到最佳。Al-Si-Cu基体合金是以剥层磨损为主要磨损机理,其磨屑是以大尺寸的板块状磨屑为主,而12 vol.%GNPs/Al-Si-Cu复合材料是以磨粒磨损为主要磨损机理,其磨屑则是以小尺寸板块状和细颗粒为主。

关键词： GNPs/Al-Si-Cu复合材料 GNPs含量摩擦磨损性能铸造工艺

稀土元素La变质Al-5Si合金耐磨性能研究

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轻金属 2022年第9期 48-52页

作者：张波徐冬张书维宋宝成江苏安全技术职业学院机械工程学院江苏徐州221000

利用光学显微镜、扫描电子显微镜、维氏硬度计和销盘式摩擦磨损试验机等手段,研究了稀土La变质处理对Al-5Si合金微观组织、维氏硬度和摩擦磨损性能的影响。结果表明:添加了质量分数0.5%La之后,α-Al晶粒和共晶Si相均得到明显细化,大部分... 详细信息

利用光学显微镜、扫描电子显微镜、维氏硬度计和销盘式摩擦磨损试验机等手段,研究了稀土La变质处理对Al-5Si合金微观组织、维氏硬度和摩擦磨损性能的影响。结果表明:添加了质量分数0.5%La之后,α-Al晶粒和共晶Si相均得到明显细化,大部分α-Al晶粒边界变得圆整,并且共晶Si相呈现弥散分布的细小颗粒状。Al-5Si合金基体的硬度和磨损量分别为68.71 HV和0.1644 g,添加质量分数0.5%La的合金的硬度和磨损量均达到最佳,分别为91.23 HV和0.1191 g,稀土La的加入有效增强了合金的抗磨损性能。不同稀土添加量的合金磨损机制也各不相同,未变质处理的Al-5Si合金主要为剥层磨损,而添加质量分数0.25%La和0.5%La之后,合金的磨损机制转变为磨粒磨损和粘着磨损。

关键词： La变质 Al-5Si合金磨损机制摩擦磨损性能

Seismic isolation design and resilience improvement of railway station considering the influence of near-fault pulse-like ground motions

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Earthquake Engineering and Engineering Vibration 2025年第1期24卷 257-270页

作者： Pan Yi song Jiayu Chen Qi Liu Yongxin School of Civil Engineering Southwest Jiaotong UniversityChengdu 610031China Key Laboratory of Seismic Engineering of Sichuan Province Chengdu 610031China

To improve the resilience of railway stations,a typical station was selected as the research object,and an isolation design was ***-four groups of near-fault pulse-like ground motions were *** seismic resilience of the no-isolation railway stations(NIRS)and the isolation railway stations(IRS)were compared to provide a numerical result of the improvement in *** results show that in the station isolation design,the station's functional requirements and structural characteristics should be considered and the appropriate placement of isolation bearings is under the waiting *** the action of a rare earthquake,the repair cost,repair time,rate of harm and death of the IRS were decreased by 8.04 million,18.30 days,6.93×10^(-3)and 1.21×10^(-3),respectively,when compared to the *** IRS received a seismic resilience grade of three-stars and the NIRS only one-star,indicating that rational isolation design improves the seismic resilience of ***,for the design of stations close to earthquake faults,it is suggested to utilize appropriate isolation techniques to improve their seismic resilience.

关键词： railway station near-fault pulse-like ground motion isolation design seismic resilience resilience improvement

Satellite-assisted 6G wide-area edge intelligence:dynamics-aware task offloading and resource allocation for remote IoT services

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Science China(Information Sciences) 2025年第2期68卷 248-268页

作者： Di ZHAO Rui DING Bin song State Key Laboratory of Integrated Services Networks Xidian University Hangzhou Institute of Technology Xidian University China Satellite Network Group Co. Ltd.

Future 6G networks will integrate non-terrestrial communication with mobile edge computing to enable wide-area edge intelligence, providing ubiquitous communication and computation services for everyone and everything. In this paper, we introduce the intelligent cloud-edge-device architecture into low Earth orbit(LEO) satellite-supported remote Internet of Things(IoT) networks to facilitate latency-sensitive and compute-intensive IoT applications. However, the dynamic spatio-temporal characteristics inherent in LEO satellite networks, such as the high volatility of task traffic and the high mobility of space nodes, pose severe challenges. For efficient task execution, we investigate the joint optimization of cross-region task offloading and cross-domain resource allocation, and innovatively propose a spatio-temporal attention-based proximal policy optimization(STA-PPO) algorithm. Specifically, the temporal attention-based actor network analyzes the timing dependencies of task arrival and makes time-variant decisions. Simultaneously, the spatial attention-based critic network captures the spatial variations of satellite motion and evaluates the topology-related value. We verify the effectiveness of the cloud-edge-device collaboration through extensive simulations. Numerical results demonstrate that the STA-PPO algorithm outperforms benchmarks, showing the lowest system delay and the highest link throughput.

关键词： 6G wide-area edge intelligence cross-region task offloading cross-domain resource allocation spatio-temporal attention proximal policy optimization

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Molecular dynamics simulations of helium transport through inorganic mineral nanopores

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Science China Earth Sciences 2025年第1期68卷 237-252页

作者： Dandan song Ping GUAN Chi ZHANG Jiahao REN School of Earth and Space Sciences Peking UniversityBeijing100871China

Helium transport through nanoscale inorganic mineral pores and pore throats is essential for its overall *** elucidate helium's transport dynamics within nanopores,we employed equilibrium and non-equilibrium molecular dynamics simulations to investigate helium's static self-diffusion and pressure-driven flow in quartz slit-shaped *** also introduced water and various gases,including hydrogen,methane,ethane,nitrogen,and carbon dioxide,into the nanopores to assess their influence on helium *** findings indicate minimal helium adsorption on quartz pore *** conditions where the pore size is less than 5 nm and the pressure under 10 MPa,environmental factors markedly influence helium *** pore sizes,high temperatures,and low gas pressures enhance helium desorption and facilitate faster *** observed a positive correlation between helium flow velocity and factors such as pore size,pressure gradient,and surface smoothness of the ***,the presence of pore water and carrier gases in quartz nanopores,which diffuse more slowly than helium,tends to reduce helium surface adsorption and slow its *** the carrier gases studied,nitrogen showed similar adsorption capacity,diffusivity,and stability to helium,while carbon dioxide displayed the highest adsorption capacity and the slowest diffusion rate,markedly differing from *** on the simulation results,we concluded that water and carrier gases primarily function as transport mediums in helium migration,moving together with ***,which shares similar properties with helium,effectively assists in this co-migration ***,carbon dioxide,due to its high adsorption capacity and slow diffusion,tends to be lost during *** a result,gas reservoirs with high nitrogen levels and low carbon dioxide levels are more likely to have higher helium ***,the smaller pore sizes and higher gas pressures in caproc

关键词： Helium transport Slit nanopores Molecular dynamics simulations Diffusion Flow carriers

基于CiteSpace中国新闻与传播专业硕士教育研究:述评与展望

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乐山师范学院学报 2023年第12期38卷 131-140页

作者：郑勇华宋宝成贵州民族大学传媒学院贵州贵阳550025

新闻与传播专业硕士(简称MJC)在新闻传播高等教育内涵式发展中扮演重要角色。为厘清MJC教育的发展脉络和研究现状,文章借助CiteSpace工具,对138篇关于MJC教育的学术文献进行计量分析。研究发现,MJC教育研究经历了应用型新闻传播人才培... 详细信息

新闻与传播专业硕士(简称MJC)在新闻传播高等教育内涵式发展中扮演重要角色。为厘清MJC教育的发展脉络和研究现状,文章借助CiteSpace工具,对138篇关于MJC教育的学术文献进行计量分析。研究发现,MJC教育研究经历了应用型新闻传播人才培养、卓越新闻传播人才培养1.0和2.0三个阶段;研究机构主要集中在新闻传播学科实力较强的院校;研究群体呈现出大分散、小聚集的特点;MJC定位与内涵、困境与挑战、以及教学改革等是主要研究议题。在双一流建设和新文科背景下,MJC教育研究将需要进一步推动多学科之间交叉融合和本土化特色情景研究,不断深化研究内容,更新研究导向,并引入新的研究方法。

关键词：新闻与传播硕士专业硕士计量综述 CiteSpace

Evaluating complementaries among urban water,energy,infrastructure,and social Sustainable Development Goals in China

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Journal of Environmental Sciences 2025年第3期149卷 585-597页

作者： Ke Yu Yifan song Jin Lin Shen Qu School of Management and Economics Beijing Institute of TechnologyBeijing 100081China Center for Energy&Environmental Policy Research Beijing Institute of TechnologyBeijing 100081China

Urban areas’performance in water,energy,infrastructure,and socio-economic sectors is intertwined and measurable through Sustainable Development Goals(SDGs)6–*** synergy among these is critical for *** study constructs an indicator framework that reflects progress towards these urban SDGs in *** indicate underperformance in SDGs 8–11,suggesting the need for transformative *** network analysis,the research reveals complementarities among these ***,the SDG space divides into socio-economic and ecological clusters,with SDG 6(Clean Water and Sanitation)central to ***,SDG 8(Decent Work and Economic Growth)and SDG 9(Industry,Innovation,and Infrastructure)act as bridges,while greater synergies exist between SDG 12(Responsible Consumption and Production)and SDG 13(Climate Action).An in-depth view at the indicator-level shows a core-periphery structure,emphasizing indicators like SDG 6.2(Wastewater Treatment Rate)and SDG 6.6(Recycled Water Production Capacity per capita)as *** study confirms the urban SDG space’s stability and predictiveness,underscoring its value in steering well-aligned policy decisions for sustainable growth.

关键词： Sustainable development goals Synergy Urban development Policy decisions

Constraints on holographic QCD phase transitions from PTA observations

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Science China(Physics,Mechanics & Astronomy) 2025年第1期68卷 67-74页

作者： song He Li Li Sai Wang Shao-Jiang Wang Center for Theoretical Physics and College of Physics Jilin UniversityChangchun 130012China School of Physical Science and Technology Ningbo UniversityNingbo 315211China CAS Key Laboratory of Theoretical Physics Institute of Theoretical PhysicsChinese Academy of SciencesBeijing 100190China School of Fundamental Physics and Mathematical Sciences Hangzhou Institute for Advanced StudyUniversity of Chinese Academy of Sciences(UCAS)Hangzhou 310024China Theoretical Physics Division Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Physical Sciences University of Chinese Academy of Sciences(UCAS)Beijing 100049China Max Planck Institute for Gravitational Physics(Albert Einstein Institute) Am Muhlenberg 1Golm 14476Germany

The underlying physics of QCD phase transition in the early Universe remains largely unknown due to its strong-coupling nature during the quark-gluon plasma/hadron gas transition,yet a holographic model has been proposed to quantitatively fit the lattice QCD data while with its duration of the first-order phase transition(FoPT)left *** specific baryon chemical poten-tial,the first-order QCD phase transition agrees with the observational constraint of baryon ***,therefore,provides a scenario for phase transition gravitational waves(GWs)within the standard model of particle *** these background GWs could contribute dominantly to the recently claimed common-spectrum red noise from pulsar timing array(PTA)observations,the duration of this FoPT can be well constrained,and the associated primordial black holes are still allowed by current observations.

关键词： pulsar timing array QCD phase transition gravitational waves primordial black holes

Zooplankton community composition in summers of 2021and 2022 in the northern East China Sea and Yellow Sea,and their linkage with abiotic and biotic factors

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Journal of Oceanology and Limnology 2025年第1期43卷 159-176页

作者： Dongjie GUO Fang ZHANG Shuangyan ZHANG song SUN CAS Key Laboratory of Marine Ecology and Environmental Sciences Institute of OceanologyChinese Academy of SciencesQingdao 266071China College of Marine Science University of Chinese Academy of SciencesQingdao 266071China Jiaozhou Bay National Marine Ecosystem Research Station Institute of OceanologyChinese Academy of SciencesQingdao 266071China

The northern East China Sea and Yellow Sea are highly dynamic marginal seas,serving as important fishing grounds and primary areas for *** zooplankton community structure,including abundance,biovolume,and normalized biovolume size spectra(NBSS)within this ecosystem in summers 2021 and 2022 was assessed through ZooScan digital imaging *** abundances of zooplankton in summers 2021 and 2022 were 3364.22±2190.53 and 4435.52±2520.06 inds./m^(3),respectively,whereas the corresponding biovolumes were 649.10±519.63 and 1064.86±1254.87 mm^(3)/m^(3),*** copepods as the dominant zooplankton functional group in terms of abundance in both years,while chaetognath and medusae were the dominant groups in terms of *** dominance of medusae and chaetognath in terms of biovolume,along with the flatter slopes of NBSS compared to a stable community,indicated that more energy accumulated in gelatinous organisms within the study *** were significant positive relationships between temperature and tunicates or medusae,with a significantly higher population size observed in summer 2022 than in *** lower abundance and biovolume of zooplankton,mainly of small copepods,in summer 2021 may be related to the larger population size of the large jellyfish and the proliferation of green *** investigation provided basic data and fundamental insights for achieving a comprehensive understanding of zooplankton community structure and their long-term dynamics.

关键词： zooplankton community spatial distribution global warming Nemopilema nomurai Ulva prolifera