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Frontiers of Structural and Civil Engineering 2021年第3期15卷 576-594页

作者： Peng ZHU jiajing xu Wenjun QU Department of Structural Engineering Tongji UniversityShanghai200092China School of Transportation and Civil Engineering Nantong UniversityNantong226019China

Reinforced concrete beams consisting of both steel and glass-fiber-reinforced polymer rebars exhibit excellent strength,serviceability,and durability.However,the fatigue shear performance of such beams is unclear.Therefore,beams with hybrid longitudinal bars and hybrid stirrups were designed,and fatigue shear tests were performed.For specimens that failed by fatigue shear,all the glass-fiber-reinforced polymer stirrups and some steel stirrups fractured at the critical diagonal crack.For the specimen that failed by the static test after 8 million fatigue cycles,the static capacity after fatigue did not significantly decrease compared with the calculated value.The initial fatigue level has a greater influence on the crack development and fatigue life than the fatigue level in the later phase.The fatigue strength of the glass-fiber-reinforced polymer stirrups in the specimens was considerably lower than that of the axial tension tests on the glass-fiber-reinforced polymer bar in air and beam-hinge tests on the glass-fiber-reinforced polymer bar,and the failure modes were different.Glass-fiber-reinforced polymer stirrups were subjected to fatigue tension and shear,and failed owing to shear.

关键词： fatigue shear hybrid stirrups hybrid reinforcement fiber-reinforced polymer

Pyramiding favorable alleles in an elite wheatvariety in one generation by CRISPR-Cas9-mediated multiplex gene editing

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Molecular Plant 2021年第6期14卷 847-850页

作者： Jinman Luo Shaoya Li jiajing xu Lei Yan Youzhi Ma Lanqin Xia Institute of Crop Sciences(ICS) Chinese Academy of Agricultural Sciences(CAAS)Beijing 100081China

Dear Editor,Common wheat(Triticum aestivum,2n=6x=42,AABBDD)is amajor staple crop consumed by more than 30%of the world’spopulation.It is the main source of cereal-based processed prod-ucts,such as bread,cookies,pasta,and noodles.Althoughwheat production increased by 10-fold following the Green revo-lution and maker-assisted breeding over the past decades,it isstill facing unprecedented challenges in the context of globalclimate changes,growing world population,decreased farm-lands,as well as water shortages in arid and semi-arid lands.Meanwhile,the functional redundancy of genes in hexaploidywheat makes a forward genetics approach to select a desiredphenotype,especially for pyramiding of several agronomicallyimportant traits in a modern variety,very time-consuming and in some cases,impossible because of gene linkage or genedrag.

关键词： aestivum elite breeding

Multiplex network reconstruction for the coupled spatial diffusion of infodemic and pandemic of COVID-19

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International Journal of Digital Earth 2021年第4期14卷 401-423页

作者： Xiaoqi Zhang Zi-Ke Zhang Wenbo Wang Donglin Hou jiajing xu Xinyue Ye Shengwen Li Dong Furen Economic and Social Development School Wuhan UniversityWuhanPeople’s Republic of China Institute of Economics Chinese Academy of Social ScienceBeijingPeople’s Republic of China College of Media and International Culture Zhejiang UniversityHangzhouPeople’s Republic of China Alibaba Research Center for Complexity Sciences Hangzhou Normal UniversityHangzhouPeople’s Republic of China New Jersey Institute of Technology University HeightsNewarkNJUSA Texas A&M University College StationTXUSA School of Geography and Information Engineering China University of GeosciencesWuhanPeople’s Republic of China

The pandemic of COVID-19 witnessed a massive infodemic with the public being bombarded with vast quantities of information.The spreading of neutral and highly accurate reports can guide the public to self-protect and reduce the pandemic.Mis-and dis-information would intrigue panic and high exposure risk to epidemic.Although the infodemic has attracted attentions from the academia,it is still not known to what degree and in which direction the information flows contribute to the COVID-19 pandemic.To fill the gap,we apply network reconstruction techniques to rebuild the hidden multiplex network of information and COVID-19 spreading by which we aim at quantifying the interaction between the propagation of information and the spatial outbreak of COVID-19,and delineate between the positive and negative impact of information on the pandemic.By differentiating the types of media that participated in the information process,we find that in the early stage of COVID-19 pandemic,infodemic does play a critical role to amplify the risk of virus outbreak in China and the risk is even larger for those highly developed regions.Compared to the old-fashion media,the new mobile platforms impose a greater risk to reinforce the positive feedback between infodemic and COVID-19 pandemic.

关键词： Infodemic COVID-19 multiplex network spatial social network

基于多尺度损伤机制的CFRP铝合金粘接板冲击行为研究

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复合材料学报 2024年第4期41卷 2167-2179页

作者：姚潞何文涛马岩于航王艳超许家婧南通大学交通与土木工程学院南通226019 中国海洋大学工程学院青岛266100 南通大学纺织服装学院南通226019

碳纤维增强聚合物(CFRP)铝合金粘接板作为一种轻质高强的材料,被广泛用在飞机、汽车、高速列车等轻量化结构上。研究首先基于纤维/基体微观尺度建立代表性体积单元(RVE)单胞模型,预测单向CFRP的基本弹性力学参数,并通过RVE模型施加宏观... 详细信息

碳纤维增强聚合物(CFRP)铝合金粘接板作为一种轻质高强的材料,被广泛用在飞机、汽车、高速列车等轻量化结构上。研究首先基于纤维/基体微观尺度建立代表性体积单元(RVE)单胞模型,预测单向CFRP的基本弹性力学参数,并通过RVE模型施加宏观单位载荷计算宏-微观应力放大系数。其次考虑纤维基体微观失效准则与演化规律,开发复合材料宏-微观渐进损伤演化程序,再结合金属与复合材料粘接面的损伤模型,建立多尺度损伤机制的CFRP铝合金粘接板冲击仿真模型,并通过实验验证了数值模型的准确性与可靠性。最后通过数值模拟对CFRP铝合金粘接板在不同纤维铺层角度与不同纤维体积分数下的抗冲击行为进行参数化研究,结果表明纤维铺层方向对粘接板的抗冲击力学性能影响不大,而纤维体积分数对结构的冲击行为影响较大。

关键词： CFRP铝合金粘接板复合材料低速冲击微观失效多尺度模拟

Monte Carlo simulation of the diffusion-limited aggregating process of particle suspension systems

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Frontiers of Chemical Science and Engineering 2010年第3期4卷 270-274页

作者： jiajing xu Wei DAI Wenwen SHAN Lin ZHANG Yongjian TANG Research Center of Laser Fusion China Academy of Engineering PhysicsMianyang 621900China College of Mathematics and Information Science North China Institute ofWater Conservancy and Hydroelectric PowerZhengzhou 450011China Institute of Atomic and Molecular Physics Sichuan UniversityChengdu 610065China

The aggregating process of particle suspension systems is a very universal phenomena and crucial for various processes both in nature and in industry.In this paper,the aggregating process was simulated with offlattice diffusion-limited cluster-cluster aggregation(DLCA)Monte Carlo programs.The self-similar fractal structures of aggregates have been clearly demonstrated by the statistical analysis of gyration radius distribution and the existence of a scaling distribution of the reduced cluster size.The fractal dimension determined from the relationship between mass and gyration radius of aggregates was 1.80 or so.The fractal dimension of the aggregates drawn from the radial distribution function and structure factor of a single aggregate is about 1.90-2.10.It was also showed that,along with the increasing of particle volume fraction,the fractal dimension will increase in a nearly square root manner,and the spatial range of the fractal structure appearing becomes narrower.Also,the gelation transition can only occur in a particle suspension system where the particle volume fraction is greater than a critical value.

关键词： diffusion aggregating off-lattice DLCA Monte Carlo particle suspension

超声表面冲击强化对316L不锈钢疲劳性能的影响

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机械强度 2024年第1期46卷 63-69页

作者：朱蒋培漆玉婷张绍峰许家婧曹小建南通大学交通与土木工程学院南通226019 南通理工学院土木工程学院南通226002

用超声冲击方法对试件表面进行改性,可以提高316L不锈钢性能。结合拉伸试验、高周疲劳试验、扫描电子显微镜(Scanning Electron Microscope,SEM)、X射线衍射(X⁃Ray Diffraction,XRD)及能量色散谱仪(Energy Dispersive Spectrometer,EDS),测试了316及316L不锈钢的疲劳性能和断裂特性。结果表明,含碳量稍低的316L不锈钢拉伸强度及疲劳强度也略低;表面超声冲击强化可提高该奥氏体不锈钢抗拉强度约19.7%,但韧性会有所降低。316、316L、冲击处理后316L三组材料的疲劳极限分别为209 MPa、204 MPa、254 MPa,均为本身抗拉极限的35%左右,拟合公式S=-64+0.45σb;含碳量高的316,其S⁃N曲线数据归一性更好,试样无侧边裂缝。疲劳断面显示,裂纹源萌生于异质相或非金属夹杂,裂纹沿晶扩展,裂纹扩展区的速度波动也归因异质相。超声冲击后316L的裂纹扩展速度明显降低,断面的起伏更大,瞬断速度更快。

关键词：超声冲击含碳量 316L 不锈钢疲劳性能

返乡创业者跨界行为有助于促进商业模式创新吗?——基于混合方法的实证研究

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浙江树人学院学报 2024年第1期24卷 54-65页

作者：吴俊杰徐嘉璟浙江树人学院浙江杭州310015 浙江农林大学浙江杭州311300

乡村产业振兴以“有效吸引多维主体返乡创业”为重要路径的观点逐渐得到学界的认可。返乡创业者如何借助跨界行为、提升农创企业信息搜寻效率与创新活力,成为一项重要议题。文章在文献梳理的基础上,采用探索性案例分析与回归统计分析相... 详细信息

乡村产业振兴以“有效吸引多维主体返乡创业”为重要路径的观点逐渐得到学界的认可。返乡创业者如何借助跨界行为、提升农创企业信息搜寻效率与创新活力,成为一项重要议题。文章在文献梳理的基础上,采用探索性案例分析与回归统计分析相结合的混合方法,识别返乡创业者跨界行为的特征维度,基于双元创新学习视角,提出返乡创业者跨界行为影响商业模式的机理模型。在此基础上,以浙苏皖237名返乡创业者为样本,对问卷调研数据进行统计处理,得出以下三个结论:第一,跨界行为中的使节行为、协调行为、侦测行为,均对返乡创业企业商业模式创新有正向促进作用;第二,探索式学习与使节行为、协调行为存在显著的互补效应,但与侦测行为的互补效应不明显;第三,利用式学习与侦测行为存在显著的互补效应,但与使节行为、协调行为间的替代效应不明显。上述研究结论有助于客观评价返乡创业者跨界行为绩效,并提供管理实践依据。

关键词：返乡创业者跨界行为商业模式创新创业学习

2024年1月23日新疆乌什7.1级地震震源参数的初步分析

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中国地震 2024年第1期40卷 260-270页

作者：徐佳静韩光洁席楠张雅茜孙丽中国地震台网中心北京100045

北京时间2024年1月23日2时9分,新疆阿克苏地区乌什县(41.26°N,78.63°E)发生7.1级地震。中国地震预警网于震后12.2s产出首报预警信息,中国地震台网中心于震后3min发布自动速报结果,震后13min发布正式速报结果,同时联合多家单位启动地... 详细信息

北京时间2024年1月23日2时9分,新疆阿克苏地区乌什县(41.26°N,78.63°E)发生7.1级地震。中国地震预警网于震后12.2s产出首报预警信息,中国地震台网中心于震后3min发布自动速报结果,震后13min发布正式速报结果,同时联合多家单位启动地震应急产品产出工作,产出震源参数、地震构造、历史地震、余震精定位、震源机制和震源破裂过程等应急产品。结果显示,本次地震是一次发生在青藏高原西缘的逆冲型地震事件,余震展布呈NEE向;主震破裂持续时间约15s,主要能量约在震后8s释放,最大位移量约2.3m,破裂长度约32km;极震区推测烈度达Ⅷ度,区域涉及乌什县、阿合奇县,面积约4614km2;震中附近多个台站峰值加速度值大于该区设防标准,存在造成部分房屋和道路损坏的可能,经对比,与实际震害调查结果相吻合。

关键词：乌什地震数据产品震源机制破裂过程地震烈度

Charge-asymmetry Fe_(1)Cu single-atom alloy catalyst for efficient oxygen reduction reaction

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Nano Research 2024年第6期17卷 4702-4710页

作者： xudong Niu Jian Wei Dongyao xu jiajing Pei Rui Sui School of Chemical&Environmental Engineering China University of Mining and TechnologyBeijing 100083China Institute of Water Ecology and Environment Chinese Research Academy of Environmental SciencesBeijing 100083China Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China Engineering Research Center of Advanced Rare Earth Materials Department of ChemistryTsinghua UniversityBeijing 100084China

The development of high-efficient and low-cost oxygen reduction reaction(ORR)electrocatalysts is crucial for the practical applications of metal-air batteries.One promising way is to develop Fe single-atom catalysts.However,the single active center and inherent electronic structure of Fe single-atom catalysts lead to the undesirable adsorption of multiple ORR intermediates.Herein,a charge-asymmetry single-atom alloy(SAA)catalyst with Fe-Cu dual sites supported on nitrogen-doped carbon nanosheet(Fe_(1)Cu SAA/NC)was constructed.Various characterizations manifest the existence of electron interaction between Fe and Cu in Fe_(1)Cu SAA/NC,which facilitates the adsorption of ORR intermediate for fast kinetics.Consequently,the charge-asymmetry Fe_(1)Cu SAA/NC exhibits much faster ORR kinetics with a half-wave potential of 0.917 V vs.reversible hydrogen electrode(RHE),outperforming its counterparts in the references.Furthermore,Fe_(1)Cu SAA/NC still maintains a high half-wave potential with only a drop of 5 mV after 5000 cycles,indicating excellent stability.This work provides a new strategy to design highly active and non-noble metal ORR electrocatalysts,which hold great potential for various catalytic applications.

关键词： Fe_(1)Cu single-atom alloy(SAA) electrocatalysis oxygen reduction reaction charge-asymmetry

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南京市“10分钟社区健身圈”研究

当代体育科技 2024年第17期14卷 64-68页

作者：朱羽徐佳静于水韵杜晴曹佳颖周晶南京体育学院江苏南京210033

该研究旨在深入探讨南京市“10分钟社区健身圈”的现状、存在的问题及改进措施。通过文献综述、问卷调查和实地考察等多种方法,对南京市内多个“10分钟社区健身圈”进行了全面的研究分析。研究发现,南京市“10分钟社区健身圈”在设施配... 详细信息

该研究旨在深入探讨南京市“10分钟社区健身圈”的现状、存在的问题及改进措施。通过文献综述、问卷调查和实地考察等多种方法,对南京市内多个“10分钟社区健身圈”进行了全面的研究分析。研究发现,南京市“10分钟社区健身圈”在设施配置、空间布局以及维护管理等方面存在不足,影响了居民参与健身活动的积极性和效果。同时,该研究也揭示了居民对社区健身圈的需求和期望,包括设施的多样性、便捷性以及良好的维护管理等。基于上述研究,该文提出了一系列改进建议,包括加强设施配置、完善维护管理以及提高居民参与度等,以期为南京市“10分钟社区健身圈”的未来发展提供参考和借鉴。

关键词： “10分钟社区健身圈” 城市规划全民健身城市社区