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Dissociation of edge and screw pyramidal Ⅰ and Ⅱ dislocations in magnesium

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Journal of Magnesium and Alloys 2023年第12期11卷 4498-4512页

作者： Yang Yang Fei Liu kefan chen Boyu Liu Zhiwei Shan Bin Li Department of Chemical and Materials Engineering University of NevadaRenoNV 89557USA Center for Advancing Materials Performance From The Nanoscale(CAMP-Nano)and Hysitron Applied Research Center in China(HARCC) State Key Laboratory for Mechanical Behavior of MaterialsXi’an Jiaotong UniversityXi’an 710049PR China

Pyramidal dislocations in magnesium (Mg) and other hexagonal close-packed metals play an important role in accommodating plastic strains along the *** single crystal Mg only presents very limited plasticity in c-axis compression,and this behavior was attributed to out-of-plane dissociation of pyramidal dislocations onto the basal plane and resulted in an immobile dislocation *** contrast,other simulations and experiments reported in-plane dissociation of pyramidal dislocations on their slip ***,the core structure and mode of dissociation of pyramidal dislocations are still not well *** better understand the dissociation behavior of pyramidal dislocations in Mg at room temperature,in this work,atomistic simulations were conducted to investigate four types of pyramidal dislocations at 300 K:edge and screw Py-Ⅰ on{1011},edge and screw Py-Ⅱ on{1122}by using a modified embedded atom method (MEAM) potential for Mg and anisotropic elasticity dislocation *** results show that when energy minimization was performed before relaxation,in-plane dissociation of edge dislocations on respective pyramidal plane could be obtained at room temperature for all four types of *** energy minimization,the edge dislocations dissociated out-of-plane onto the basal *** of potential energy and hydrostatic stress of individual atoms at the edge dislocation core show that the extraordinarily high energy and atomic stresses in the as-constructed dislocation structures caused the out-of-plane dissociation onto the basal *** core structures of all four types of pyramidal dislocation after in-plane dissociation were analyzed by computing the distribution of the Burgers vector.

关键词： Magnesium Pyramidal dislocations Atomistic simulations

Analysis of Sulfate Corrosion Resistance and Reliability of Recycled Concrete

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Wuhan University Journal of Natural Sciences 2020年第3期25卷 208-216页

作者： QIAO Hongxia ZHU Xiangchen chen kefan PENG Kuan College of Civil Engineering Lanzhou University of TechnologyLanzhou 730000GansuChina

In order to study the effect of different recycled fine aggregate and recycled coarse aggregate substitution rate on the sulfate resistance of recycled concrete under dry-wet cycle conditions,the substitution rate of recycled fine aggregate and recycled coarse aggregate was designed to be 0%/0%,10%/0%,0%/25%,10%/25%,0%/50%and 10%/50%of the six groups of mixture *** mass loss rate and relative dynamic modulus of each group of test blocks were tested respectively and the optimal ratio was *** Wiener distribution probability method was used to establish the reliability function to optimize the remaining life of the *** results show that the dynamic elastic modulus and mass show a trend of increasing first and then decreasing during the dry-wet cycles of *** recycled concrete has the strongest resistance to sulfate attack under the substitution rate of recycled fine aggregate and recycled coarse aggregate is 10%and 0%,and the test blocks will be damaged after being subjected to 182 times of dry-wet cycles of *** effect of recycled coarse aggregate on the sulfate attack resistance of the test block is more obvious than that of the recycled fine aggregate,which leads to the durability of the concrete being greatly reduced.

关键词： recycled concrete dry-wet cycles of sulfate the Wiener distribution probability microscopic reaction mechanism

Influence of Zn ion implantation on structures and field emission properties of multi-walled carbon nanotube arrays

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Science China(Technological Sciences) 2010年第3期53卷 776-781页

作者： chen kefan,DENG JianHua,ZHAO Fei,chenG GuoAn &ZHENG RuiTing Key Laboratory of Beam Technology and Material Modification of Ministry of Education,College of Nuclear Science and Technology,Beijing Normal University,Beijing100875,China Key Laboratory of Beam Technology and Material Modification of Ministry of Education College of Nuclear Science and Technology Beijing Normal University Beijing China

The structures and field emission properties of multi-walled carbon nanotube arrays implanted with Zn+ by MEVVA ion implanter have been *** results revealed that Zn+implantation induced structural damage and that the top of carbon nanotubes with multi-layered graphite structure were transformed into carbon nanowires with amorphous ***,C:Zn solid solution was synthesized after Zn+ *** turn-on field and threshold field were 0.80 and 1.31 V/μm,respectively for original multi-walled carbon nanotube arrays and were reduced to 0.66 and 1.04 V/μm due to the synthesis of C and Zn composite,in which the work function was reduced after low doses of Zn+*** is indicated that low doses of Zn+implantation can improve field emission performance of multi-walled carbon nanotube ***,high doses of Zn+implantation can reduce field emission properties of multi-walled carbon nanotube arrays,because radiation damage reduces the electric field enhancement factor.

关键词： multi-walled carbon nanotubes ion implantation field electron emission

Influence and mechanism of solar radiation intensity on the interdecadal variability of strong Meiyu events during historical periods

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Science China Earth Sciences 2023年第2期66卷 408-416页

作者： Liulin WANG Liang NING kefan chen Mi YAN Jian LIU Zhengyu LIU Yanmin QIN Jiao XUE Chuxin LI Key Laboratory for Virtual Geographic Environment Ministry of Education/State Key Laboratory Cultivation Base of Geographical Environment Evolution of Jiangsu Province/Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application/School of GeographyNanjing Normal UniversityNanjing210023China Open Studio for the Simulation of Ocean-Climate-Isotope Pilot National Laboratory for Marine Science and Technology(Qingdao)Qingdao266237China Climate System Research Center Department of GeosciencesUniversity of MassachusettsAmherst01003USA State Key Laboratory of Loess and Quaternary Geology Institute of Earth EnvironmentChinese Academy of SciencesXi’an710061China Department of Geography The Ohio State UniversityColumbusOH43210USA

Most recent studies on Meiyu over the middle and lower reaches of the Yangtze River(MLRYR)have focused on its interannual variability or the mechanism of certain abnormal *** influence and physical mechanism of solar radiation intensity on the interdecadal frequency of strong Meiyu events over the MLRYR during historical periods were investigated using reconstructed precipitation data,reconstructed solar radiation data,and model simulation ***,according to the solar radiation intensity,the Ming and Qing Dynasties(1470-1850)were divided into three periods of strong solar radiation and three periods of weak solar *** was found that during the periods of strong solar radiation,the frequency of strong Meiyu events was significantly higher than that during the periods of weak solar radiation in the reconstructed precipitation data and model *** analyses show that during the periods of strong solar radiation,the Western Pacific Subtropical High(WPSH)is stronger,and the blocking highs over the middle-high-latitudes are also stronger,which is conducive to the continuous convergence of the southward cold air and the northward warm and humid air flow at the ***,a circulation spatial pattern conducive to the occurrence of strong Meiyu events is then *** probability distributions of precipitation also show that,during periods of strong solar radiation,changes in circulation patterns cause the probability distribution of precipitation to shift significantly to the right,increasing the probability of strong Meiyu events occurring on the right side of the probability distribution.

关键词： Ming Dynasty Historical flood Strong Meiyu events Solar radiation CESM-LME

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论“国潮”动画电影的艺术特色与时代价值

中国文艺评论 2024年第3期 93-103,I0003,I0004页

作者：黄诗娴陈可凡集美大学电影学院/海洋文化与法律学院

自2015年以来,一批体现民族文化内涵与艺术特征、视听制作能力具备国际先进水平,并呈现出富有深度的全年龄段现代动画美学风貌的“国潮”动画电影,开拓了中国动画电影的新风格与新路径。该类型作品以中国神话元素为基底,以重述神话为创... 详细信息

自2015年以来,一批体现民族文化内涵与艺术特征、视听制作能力具备国际先进水平,并呈现出富有深度的全年龄段现代动画美学风貌的“国潮”动画电影,开拓了中国动画电影的新风格与新路径。该类型作品以中国神话元素为基底,以重述神话为创作理念,在人物、情节、背景等内容方面承袭传统神话的内在气韵,辅之以现代叙事学与商业电影的标准范式。影像表达方面锐意进取,吸纳大量流行元素,从造型风格、时空组合、镜头语言等多方面突破了传统动画电影曾面临的困境。“国潮”动画电影既承袭与延伸神话内核,又通过“文化寻根”的方式将对当下问题的思考纳入中华传统文化的表达体系之中。

关键词：国潮动画电影神话重述大众文化

基于选举的SDN机载网络控制器故障恢复机制

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系统工程与电子技术 2020年第11期42卷 2581-2590页

作者：吕娜潘武陈柯帆刘创空军工程大学信息与导航学院陕西西安710077 中国人民解放军94860部队江苏南京210000 国防科技大学电子对抗学院安徽合肥230000

针对软件定义航空集群机载网络控制域内控制节点故障问题,将故障恢复问题转化为领导者选举问题,提出一种基于选举的软件定义机载网络控制器故障恢复机制,在控制域内选举传输节点作为新控制节点。为优化新控制节点性能,综合各传输节点平... 详细信息

针对软件定义航空集群机载网络控制域内控制节点故障问题,将故障恢复问题转化为领导者选举问题,提出一种基于选举的软件定义机载网络控制器故障恢复机制,在控制域内选举传输节点作为新控制节点。为优化新控制节点性能,综合各传输节点平均传输时延、最大请求量和平均故障率3个参数计算传输节点的权值,根据权值定义选举优先级,并提出基于优先级的控制节点选举(priority-based control node election,PBCNE)算法。实验结果表明,与现有选举算法相比,PBCNE算法的复杂度(消息数和时间量)有了明显降低,有效减少了故障恢复时延,能够快速高效地恢复控制器故障。

关键词：机载网络软件定义网络选举权值优先级故障恢复时延

节点可靠感知的差异保护虚拟航空网络映射算法

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系统工程与电子技术 2023年第8期45卷 2597-2605页

作者：缪竞成吕娜高旗陈柯帆空军工程大学信息与导航学院陕西西安710077 中国人民解放军94860部队江苏南京210000

针对集成僵化的传统航空网络难以在节点出现故障后快速高效调度网络资源,从而恢复任务执行的问题,提出了无线网络虚拟化环境下节点可靠感知的差异保护虚拟航空网络映射(node reliability-aware protection-differentiated virtual airbo... 详细信息

针对集成僵化的传统航空网络难以在节点出现故障后快速高效调度网络资源,从而恢复任务执行的问题,提出了无线网络虚拟化环境下节点可靠感知的差异保护虚拟航空网络映射(node reliability-aware protection-differentiated virtual airborne network embedding,NRPD-VANE)算法。首先,节点映射采用新的节点重要度评价方法,综合感知故障可能、无线干扰和网络资源,为虚拟节点映射可靠物理节点;其次,链路映射根据节点重要度,采用P圈保护技术对映射路径节点实行差异保护。仿真结果表明,相比传统的节点保护映射算法,所提算法在保持较低恢复时延的同时,提高了映射成功率。

关键词：航空网络网络虚拟化虚拟网络映射差异保护节点故障 P圈

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适应拓扑变化的拥塞最小化网络更新策略

航空学报 2020年第7期41卷 238-247页

作者：吕娜陈坤陈柯帆朱海峰潘武空军工程大学信息与导航学院西安710077 中国人民解放军94860部队南京210000

软件定义网络的出现推动了航空集群机载网络的发展,同时也为机载网络的一致性更新带来了挑战。针对拓扑变化导致的网络更新期间可用路径失效问题,提出适应拓扑变化的拥塞最小化网络更新策略。首先,为减少可用路径失效带来的数据包丢失,... 详细信息

软件定义网络的出现推动了航空集群机载网络的发展,同时也为机载网络的一致性更新带来了挑战。针对拓扑变化导致的网络更新期间可用路径失效问题,提出适应拓扑变化的拥塞最小化网络更新策略。首先,为减少可用路径失效带来的数据包丢失,在更新之前采用重路由机制进行处理;然后,针对重路由机制可能引起的网络拥塞,设计了贪婪流迁移算法缓解拥塞;最后,通过瞬时拥塞最小化更新算法完成整个网络更新。仿真结果表明:与传统的拥塞一致性更新算法相比,所提更新策略用规则开销、瞬时网络拥塞方面的少量提高换取了网络更新期间数据包丢失的显著降低。

关键词：航空集群机载网络软件定义网络网络更新拓扑变化容量一致性

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一种时效增强的机载网络流量识别方法

西北工业大学学报 2020年第2期38卷 341-350页

作者：吕娜周家欣冯煊陈柯帆陈旿空军工程大学信息与导航学院陕西西安710077 中国人民解放军31006部队北京100000 西北工业大学网络空间安全学院陕西西安710072

机载网络拓扑动态性强,带宽受限等特点导致其难以为多样化的航空集群作战任务提供可靠的信息交互服务,因此需要对网络中的“大流量对象”进行实时识别,从而优化流量控制,提升网络性能。针对该问题,基于机器学习贝叶斯模型,提出一种时效... 详细信息

机载网络拓扑动态性强,带宽受限等特点导致其难以为多样化的航空集群作战任务提供可靠的信息交互服务,因此需要对网络中的“大流量对象”进行实时识别,从而优化流量控制,提升网络性能。针对该问题,基于机器学习贝叶斯模型,提出一种时效增强的流量识别方法,首先通过对原始流量数据集进行预处理得到数据流训练子集,并基于贝叶斯网络模型构造子分类器,然后基于多窗口动态贝叶斯网络分类器模型实现大流量对象的早期识别。仿真结果表明,相较于现有的大流识别方法,所提方法可以在保证识别准确性的条件下有效提升识别时效性。

关键词：流量识别机器学习贝叶斯网络航空集群机载网络