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Chinese Journal of Chemical Engineering 2024年第5期69卷 1-12页

作者： zhekun chen Weitong Pan Longfei Tang Xueli chen Fuchen Wang Engineering Research Center of Resource Utilization of Carbon-containing Waste with Carbon Neutrality Ministry of EducationEast China University of Science and TechnologyShanghai 200237China Key Laboratory of Pressure Systems and Safety Ministry of EducationEast China University of Science and TechnologyShanghai 200237China

Ensuring the consistency of electrode structure in proton-exchange-membrane fuel cells is highly desired yet challenging because of wide-existing and unguided cracks in the microporous layer(MPL). The first thing is to evaluate the homogeneity of MPL with cracks quantitatively. This paper proposes the homogeneity index of a full-scale MPL with an area of 50 cm~2, which is yet to be reported in the literature to our knowledge. Besides, the effects of the carbon material and surfactant on the ink and resulting MPL structure have been studied. The ink with a high network development degree produces an MPL with low crack density, but the ink with high PDI produces an MPL with low crack homogeneity. The polarity of the surfactant and the non-polarity of polytetrafluoroethylene(PTFE) are not mutually soluble,resulting in the heterogeneous PTFE distribution. The findings of this study provide guidelines for MPL fabrication.

关键词： Proton-exchange-membrane fuel cell Microporous layer Crack density Crack homogeneity Polytetrafluoroethylene distribution Surfactant

All-optical vector visual cryptography with high security and rapid decryption

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Opto-Electronic Advances 2023年第5期6卷 1-3页

作者： zhekun chen Minghui Hong Pen-Tung Sah Institute of Micro-Nano Science and Technology Xiamen UniversityXiamen 361005China

Meta optics-empowered vector visual cryptography at the abundant degrees of freedom of light and spatial dislocation can open an avenue for optical information security and anti-counterfeiting with a compact footprint... 详细信息

关键词： visual optical optics

There discovery of alpine oak (Heterobalanus group, Quercus section Ilex, Fagaceae) fossils from Mount Shisha Pangma and its significance

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Paleogene integrative stratigraphy,biotas,and paleogeographical evolution of the Qinghai-Tibetan Plateau and its surrounding areas

ACTA PETROLOGICA SINICA 2024年第5期40卷 1382-1393页

作者： Su, Tao Liu, jia chen, Linlin Huang, Jian Zhang, Xinwen Wu, Feixiang Ni, Xijun Deng, Tao Zhou, zhekun chengdu Univ Technol Inst Sedimentary Geol MNR Key Lab Deeptime Geog & Environm Reconstruct Chengdu 610059 Peoples R China chengdu Univ Technol State Key Lab Oil & Gas Reservoir Geol & Exploita Chengdu 610059 Peoples R China Chinese Acad Sci Xishuangbanna Trop Botan Garden CAS Key lab Trop Forest Ecol Mengla 666303 Peoples R China Univ Bristol Sch Geograph Sci Bristol BS8 1QU Avon England Chinese Acad Sci Inst Vertebrate Paleontol & Paleoanthropol CAS Key Lab Veribrate Evol & Human Origins Beijing 100044 Peoples R China

We reported alpine oak fossil leaves ( the Heterobalanus group, Quercus section Ilex, Fagaceae) rediscovered on Mount Shisha Pangma. According to twice field investigations, the fossil site is located at the front of the No. 5 glacier tongue on the south side of the Dasuopu Glacier at an altitude of about 5800m on the north slope of Shisha Pangma Peak. These fossils are from the siltstone interlayer dominated by sandy conglomerate in the lower part of the Yebokangjiale Group. These newly discovered fossil leaves have typical characteristics of alpine oaks, including oval or oblong leaf, thick and short petiole, entire or toothed leaf margin, and 5 similar to 6 pairs of secondary veins, which is completely consistent with the leaf morphology of alpine oaks from Mount Shisha Pangma reported previously. Through morphological comparison with living and fossil species in this group, as well as quantitative analysis combined with geometric morphometry, these fossil leaves from Mount Shisha Pangma were assigned to Quercus preguajavifolia Tao. Alpine oaks may originate in southeastern margin of the Qinghai -Tibetan Plateau, then thrive locally and spread into regions nearby accompanying by the uplift of the plateau. The implication of alpine oak fossil leaves from Mount Shisha Pangma on paleoelevation needs to be further investigated due to the present wide range and the uncertainty of these fossils. The rediscovery of alpine oak fossils from Mount Shisha Pangma not only helps to clarify the specific layers bearing these fossils, but also further enriches the morphological characteristics of this fossil record and its systematic position. This discovery would provide important basis for better revealing the evolution of biodiversity and environmental changes in the middle part of the Himalaya during the Cenozoic.

关键词： Heterobalanus Leaf fossil Himalaya Mountain uplift Biodiversity Neogene LATE MIOCENE TIBETAN PLATEAU ELEVATION EXHUMATION EVOLUTION HIMALAYA OROGEN UPLIFT

来源：博看期刊评论

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Science China Earth Sciences 2024年第4期67卷 1290-1325页

作者： Jia LIU Ai SONG Lin DING Tao SU zhekun ZHOU CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMengla 666303China State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and PalaeontologyChinese Academy of SciencesNanjing 210008China Institute of Paleontology Yunnan UniversityKunming 650500China State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

The Paleogene is a crucial period when terrestrial and marine ecosystems recovered from major disruptions and gradually approached their modern states.In the Qinghai-Tibetan Plateau and its surrounding regions,the Paleogene also represents a significant phase of tectonic evolution in the Qinghai-Tibetan Plateau-Himalaya orogeny,reorganization of Asian climates,and evolution of biodiversity.Due to limitations in research conditions and understanding,there are still many controversies regarding stratigraphic divisions in the Qinghai-Tibetan Plateau and its surrounding regions.In recent years,extensive studies on sedimentary petrology,magnetostratigraphy,and isotope dating have been conducted in the region.Numerous fossils have been discovered and reported,contributing to a more systematic understanding of biostratigraphy.These studies have laid a solid foundation for the comprehensive investigation of the stratigraphy,biotas and paleogeographic evolution of the Qinghai-Tibetan Plateau and its surrounding regions during the Paleogene.In this paper,we integrate recent research on fossils,isotopic dating,magnetostratigraphy,and geochemistry to refine the stratigraphic divisions and correlation framework of different tectonic units in the region,building upon previous studies.Since the Second Tibetan Plateau Scientific Expedition and Research,the knowledge of Paleogene floras has gradually expanded.This paper discusses the biostratigraphic significance of extinct and newly appeared taxa based on the latest dating results of these plant species.The new understanding of fossil species such as the“Eucalyptus”and Arecaceae establishes connections between the Paleogene flora of the Qinghai-Tibetan region and the biotas of Gondwana,specifically Oceania and South America.The evolutionary history of key taxa near the Yarlung Zangbo suture zone indicates that the collision between the Indian and Eurasian plates occurred approximately 65-54 Ma.Paleoelevation reconstructions,based on plant fossils,suggest that the Hengduan Mounta

关键词： Qinghai-Tibetan Plateau Fossils Biostratigraphy Paleoenvironment Paleogeography Paleogene

质子交换膜燃料电池微孔层浆液微观结构与流变性

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化工进展 2022年第7期41卷 3808-3815页

作者：陈哲坤潘伟童姚顶松丁路王辅臣华东理工大学洁净煤技术研究所上海200237

微孔层(MPL)是质子交换膜燃料电池(PEMFC)水管理的重要部件。本文系统性选择了4种典型炭黑[ACET、XC-72R、BP2000、天然气裂解炭黑(NG)],借助原子力显微镜(AFM)、场发射透射电镜(TEM)和动态光散射粒度分析仪(DLS PSD)对浆液微观结构的研... 详细信息

微孔层(MPL)是质子交换膜燃料电池(PEMFC)水管理的重要部件。本文系统性选择了4种典型炭黑[ACET、XC-72R、BP2000、天然气裂解炭黑(NG)],借助原子力显微镜(AFM)、场发射透射电镜(TEM)和动态光散射粒度分析仪(DLS PSD)对浆液微观结构的研究,给出团聚性这一浆液评价标准,并结合流变性揭示了定量标准。研究结果表明,不同炭黑的团聚程度大小依次为ACET>XC-72R>BP2000>NG。剪切稀化指数n越大,MPL浆液团聚程度越低,颗粒分散越均匀;n越小,团聚程度越高。具体而言,固含量α=6%时,添加NG、BP2000、XC-72R、ACET炭黑的MPL浆液的剪切稀化指数n分别为0.554、0.320、0.118、0.039;测得的ACET、XC-72R、BP2000、NG的团聚体粒径分别为1.358μm、1.149μm、0.732μm、0.406μm,所以浆液的剪切稀化指数与其团聚程度成反比。总之,NG-MPL剪切稀化程度最低,NG更加适合作为MPL的碳材料,也为今后MPL的制备和优化提供指导。

关键词：燃料电池微孔层炭黑微观结构流变性

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智能财务建设发展研究

商业观察 2023年第23期9卷 37-39,51页

作者：李铭陈哲昆中原工学院经济管理学院河南郑州450007

随着数字经济的不断发展,以人工智能为代表的数字化信息技术推动了智能财务建设的发展。立足于会计信息化发展规划中提及的切实推动会计管理工作数字化转型的背景,对智能财务的研究会驱动企业财务工作不断向高质量方向发展,因此文章将... 详细信息

随着数字经济的不断发展,以人工智能为代表的数字化信息技术推动了智能财务建设的发展。立足于会计信息化发展规划中提及的切实推动会计管理工作数字化转型的背景,对智能财务的研究会驱动企业财务工作不断向高质量方向发展,因此文章将对智能财务建设的发展进行脉络梳理和总结。

关键词：智能财务业财融合财务共享财务管理

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激光烧蚀硅基表面抗反射微结构的声信号监测

光学学报 2023年第9期43卷 221-232页

作者：黄维鹏周锐陈哲堃袁公发廖启乐厦门大学萨本栋微米纳米科学技术研究院福建厦门361005 中国福建能源材料科学与技术创新实验室福建厦门361005

为了提高抗反射硅表面制备的加工质量、缩短研制周期,提出了一种基于时频域处理的面向激光加工过程的声波信号在线监测及分析方法。利用声信号的时频谱图分析了0~30 kHz内的声信号与激光烧蚀形成的表面微结构特征尺寸之间的相关性,具体... 详细信息

为了提高抗反射硅表面制备的加工质量、缩短研制周期,提出了一种基于时频域处理的面向激光加工过程的声波信号在线监测及分析方法。利用声信号的时频谱图分析了0~30 kHz内的声信号与激光烧蚀形成的表面微结构特征尺寸之间的相关性,具体分析了激光功率及加工次数对微结构深度及声信号各频率幅值变化的影响。以声信号作为输入,基于人工神经网络对加工质量进行预测。实验结果表明:通过监测激光加工时产生的声信号能够明确反映被烧蚀硅表面是否形成周期性微结构,且微结构宽度不同,其对应的声信号频率组成也不同。在微结构宽度固定的情况下,归一化后的声信号特征参数随微结构深度线性变化,且受到激光功率变化的影响忽略不计。以硅基表面5%的反射率作为加工质量分界线,采用人工神经网络对加工质量的预测结果与实际测量结果的准确率可以超过90%。结果表明:声波在线监测可以有效应用于评估表面加工质量,为抗反射硅表面制备过程的实时监测提供了理论依据。

关键词：表面光学激光烧蚀抗反射硅基表面声发射信号实时监测人工神经网络

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印度国内政治冲突的空间分异及驱动因子

世界地理研究 2024年第1期33卷 57-69页

作者：蔡中祥黄哲琨公茂玉郭勇胡盛铭王岩信息工程大学郑州450001

为揭示2010—2021年印度国内政治冲突的空间分异性成因,基于武装冲突地点和事件数据项目所收录的印度政治冲突数据,结合印度各邦驱动因素值,运用Z-score标准化、相关性分析等方法构建驱动因子体系,运用地理探测器对上述驱动因子进行探测... 详细信息

为揭示2010—2021年印度国内政治冲突的空间分异性成因,基于武装冲突地点和事件数据项目所收录的印度政治冲突数据,结合印度各邦驱动因素值,运用Z-score标准化、相关性分析等方法构建驱动因子体系,运用地理探测器对上述驱动因子进行探测,结果表明:(1)14个驱动因子全部通过了显著性检验,其中穆斯林人口比、民族数、非官方政党占比、人口密度等因素单因子驱动力较强。(2)进行双因子交互,各驱动因子交互后q值有明显增长,平均增长率为266%,可知印度国内政治冲突是由多种驱动因子共同作用的结果,具有多重叠加效应,呈现“1+1>2”的作用机制;宗教民族类因子与其他类交互后,对空间分异性的解释性最大。(3)印度应改善地区政治安全局势,应优先解决宗教对抗、民族分离、粮食产量不稳定、水资源合理利用等问题。

关键词：政治冲突空间分异性驱动因子地理探测器印度

2001-2020年巴基斯坦恐怖袭击事件时空演变分析

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世界地理研究 2024年第5期33卷 60-72页

作者：蔡中祥黄哲琨郭勇公茂玉王岩常耀伟信息工程大学郑州450001 32021部队北京100000

为揭示2001—2020年巴基斯坦恐怖袭击事件的时空演变规律,基于全球恐怖主义数据库收录数据,采用核密度、标准差椭圆、空间自相关等地理统计方法进行分析研究,结果表明:2001—2020年巴基斯坦恐怖主义形势经历了三个阶段,阶段转折点与政... 详细信息

为揭示2001—2020年巴基斯坦恐怖袭击事件的时空演变规律,基于全球恐怖主义数据库收录数据,采用核密度、标准差椭圆、空间自相关等地理统计方法进行分析研究,结果表明:2001—2020年巴基斯坦恐怖主义形势经历了三个阶段,阶段转折点与政治权力交替高度吻合;空间分布从“三角形”转变为“N字形”,形成了以卡拉奇、白沙瓦、奎达为核心的3大恐怖袭击聚集区,伤亡人数的密度值显著减小,但恐袭活动范围有所增大,且卡拉奇、奎达地区恐袭密度值下降不明显;不同阶段恐袭事件的空间自相关呈现分异性,原FATA、奎达聚集区聚类特征主要为H-H特征,而卡拉奇聚集区为H-L特征;使用爆炸物的恐怖袭击频次最多,近年来,对军事、警察和记者媒体的袭击开始增多;巴基斯坦恐袭事件的演变受认同因素、政治因素、社会经济因素、地理位置因素等驱动,并被宗教极端主义和民族分离势力利用,造成巴基斯坦恐袭事件范围不断扩大、中心城市成重灾区、影响愈发恶劣等后果。

关键词：恐怖袭击空间自相关重心迁移驱动因素巴基斯坦

习近平关于新质生产力重要论述的生成逻辑与实践路径

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陕西青年职业学院学报 2024年第2期 8-11,21页

作者：梁哲琨刘先江湖南师范大学湖南长沙40081

习近平关于新质生产力重要论述是习近平经济思想的重要组成部分,具有严密的生成逻辑。新质生产力是指创新起主导作用,摆脱传统经济增长方式的先进生产力质态,以马克思主义生产力理论作为直接的理论来源,是对中国共产党解放和发展生产力... 详细信息

习近平关于新质生产力重要论述是习近平经济思想的重要组成部分,具有严密的生成逻辑。新质生产力是指创新起主导作用,摆脱传统经济增长方式的先进生产力质态,以马克思主义生产力理论作为直接的理论来源,是对中国共产党解放和发展生产力历程的探索与总结,回应了应对世界百年未有之大变局的现实需要。贯彻落实习近平关于新质生产力重要论述,以新质生产力推进中国式现代化发展,要坚持从实际出发,先立后破、因地制宜、分类指导;要抢抓机遇,加大创新力度;要深化科技体制、教育体制、人才体制等改革,进而推动经济高质量发展。

关键词：新质生产力生成逻辑实践路径