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Spatial Distribution and Influencing Factors of Urban Shrinkage from the Perspective of Factor Flow - A Case Study of National Urban Agglomerations
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作者 yuheng sun Zhifei Ma Huan Huang 《Journal of Architectural Research and Development》 2023年第5期77-85,共9页
This paper examines national urban agglomerations by taking factor flows as the focal point as the research subject.By dividing the stages of urban agglomeration development,a comprehensive framework of urban shrinkag... This paper examines national urban agglomerations by taking factor flows as the focal point as the research subject.By dividing the stages of urban agglomeration development,a comprehensive framework of urban shrinkage is constructed,encompassing economic,population,and social shrinkage.The study explores the spatial distribution characteristics of urban shrinkage during different stages of urban agglomeration and investigates the influencing factors using a geographic detector model.The findings reveal that urban shrinkage within urban agglomerations is widely spread,predominantly in peripheral areas.During the diffusion stage,urban shrinkage is scattered,with population shrinkage concentrated in peripheral regions,economic shrinkage concentrated on old industrial cities,and social shrinkage concentrated on the northeast.The outcomes of the geographic detector model indicate that traffic flow,capital flow,information flow,node importance,network connectivity,government investment,openness,and environmental regulations all play significant roles in shaping the spatial distribution of urban shrinkage. 展开更多
关键词 Urban shrinkage Factor flow National urban agglomeration
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金属有机骨架材料在金属锂电池界面的应用 被引量:4
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作者 孙宇恒 高铭达 +5 位作者 李慧 徐丽 薛晴 王欣然 白莹 吴川 《物理化学学报》 SCIE CAS CSCD 北大核心 2021年第1期39-54,共16页
金属锂电池是下一代高能量密度电池体系的代表。然而,高比能金属锂电池的发展受到界面诸多问题的限制,如:金属锂负极枝晶生长、隔膜界面兼容性、正极界面不稳定等,影响了金属锂电池的界面传质传荷过程,并导致金属锂界面环境恶化、电池... 金属锂电池是下一代高能量密度电池体系的代表。然而,高比能金属锂电池的发展受到界面诸多问题的限制,如:金属锂负极枝晶生长、隔膜界面兼容性、正极界面不稳定等,影响了金属锂电池的界面传质传荷过程,并导致金属锂界面环境恶化、电池的容量衰减、安全性能下降等问题。金属有机骨架(MOF)是一种具有稳定多孔结构的有机无机杂化材料,近年来在高比能金属锂电池领域受到广泛关注。其多孔结构与开放的金属位点(OMs)提供了优异的离子电导率,稳定的空间结构提供了较高的机械强度,多样的官能团与金属节点带来丰富的功能性。本文分析了金属锂电池界面的主要挑战,结合金属锂界面的成核模型,总结了MOF及其衍生材料在解决锂金属负极界面、隔膜界面、以及正负极界面稳定性相互作用等方面的研究进展和作用机理,为解决高比能金属锂电池界面失稳问题提供了解决途径,并展望了MOF基材料的设计与发展方向。 展开更多
关键词 金属锂负极 金属有机骨架 界面防护 隔膜 电解液 金属锂电池
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Deer Body Adaptive Threshold Segmentation Algorithm Based on Color Space 被引量:5
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作者 yuheng sun Ye Mu +4 位作者 Qin Feng Tianli Hu He Gong Shijun Li Jing Zhou 《Computers, Materials & Continua》 SCIE EI 2020年第8期1317-1328,共12页
In large-scale deer farming image analysis,K-means or maximum between-class variance(Otsu)algorithms can be used to distinguish the deer from the background.However,in an actual breeding environment,the barbed wire or... In large-scale deer farming image analysis,K-means or maximum between-class variance(Otsu)algorithms can be used to distinguish the deer from the background.However,in an actual breeding environment,the barbed wire or chain-link fencing has a certain isolating effect on the deer which greatly interferes with the identification of the individual deer.Also,when the target and background grey values are similar,the multiple background targets cannot be completely separated.To better identify the posture and behaviour of deer in a deer shed,we used digital image processing to separate the deer from the background.To address the problems mentioned above,this paper proposes an adaptive threshold segmentation algorithm based on color space.First,the original image is pre-processed and optimized.On this basis,the data are enhanced and contrasted.Next,color space is used to extract the several backgrounds through various color channels,then the adaptive space segmentation of the extracted part of the color space is performed.Based on the segmentation effect of the traditional Otsu algorithm,we designed a comparative experiment that divided the four postures of turning,getting up,lying,and standing,and successfully separated multiple target deer from the background.Experimental results show that compared with K-means,Otsu and hue saturation value(HSV)+K-means,this method is better in performance and accuracy for adaptive segmentation of deer in artificial breeding scenes and can be used to separate artificially cultivated deer from their backgrounds.Both the subjective and objective aspects achieved good segmentation results.This article lays a foundation for the effective identification of abnormal behaviour in sika deer. 展开更多
关键词 Artificial breeding color space deer body recognition image segmentation K-MEANS multi-target recognition OTSU
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A Novel Hybrid Tag Identification Protocol for Large-Scale RFID Systems 被引量:1
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作者 Ye Mu Ruiwen Ni +6 位作者 yuheng sun Tong Zhang Ji Li Tianli Hu He Gong Shijun Li Thobela Louis Tyasi 《Computers, Materials & Continua》 SCIE EI 2021年第8期2515-2527,共13页
Radio frequency identification technology is one of the main technologies of Internet of Things(IoT).Through the transmission and reflection of wireless radio frequency signals,non-contact identification is realized,a... Radio frequency identification technology is one of the main technologies of Internet of Things(IoT).Through the transmission and reflection of wireless radio frequency signals,non-contact identification is realized,and multiple objects identification can be realized.However,when multiple tags communicate with a singleton reader simultaneously,collision will occur between the signals,which hinders the successful transmissions.To effectively avoid the tag collision problem and improve the reading performance of RFID systems,two advanced tag identification algorithms namely Adaptive M-ary tree slotted Aloha(AMTS)based on the characteristics of Aloha-based and Query tree-based algorithms are proposed.In AMTS,the reader firstly uses the framed slotted Aloha protocol to map the tag set to different time slots,and then identify the collided tags using binary search method based on collision factor or mapping table.Both performance analysis and extensive experimental results indicate that our proposed algorithms significantly outperforms most existing anti-collision approaches in tag dense RFID systems. 展开更多
关键词 RFID ANTI-COLLISION ALOHA MULTI-TREE AMTS
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