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An alternative 2D ICEEMDAN-based denoising method and its application in processing magnetic anomaly data

Geodesy and Geodynamics 2024年第5期15卷 465-476页

作者： Jun Xu Jinsong Du changqing yuan School of Geophysics and Geomatics China University of GeosciencesWuhan 430074China Hubei Subsurface Multi-scale Imaging Key Laboratory China University of GeosciencesWuhan 430074China State Key Laboratory of Geological Processes and Mineral Resources China University of GeosciencesWuhan 430074China Key Laboratory of Geological Survey and Evaluation of Ministry of Education China University of GeosciencesWuhan 430074China

Due to environmental noise and human factors,magnetic data collected in the field often contain various noises and interferences that significantly affect the subsequent data processing and *** Mode Decomposition(EMD),an adaptive multiscale analysis method for nonlinear and non-stationary signals,is widely used in geophysical and geodetic data *** with traditional EMD,Improved Complete Ensemble EMD with Adaptive Noise(ICEEMDAN)is more effective in addressing the problem of mode *** on the principles of 1D ICEEMDAN,this paper presents an alternative algorithm for 2D ICEEMDAN,extending its application to two-dimensional *** effectiveness of the proposed approach is demonstrated through synthetic signal experiments,which show that the 2D ICEEMDAN exhibits a weaker mode mixing effect compared to the traditional bidimensional EMD(BEMD)***,to improve the performance of the denoising method based on 2D ICEEMDAN and preserve useful signals in high-frequency components,an improved soft thresholding technique is *** magnetic anomaly data testing indicates that our denoising method effectively preserves signal continuity and outperforms traditional soft thresholding *** validate the practical application of this improved threshold denoising method based on 2D ICEEMDAN,it is applied to ground magnetic survey data in the Yandun area of *** results demonstrate the effectiveness of the method in removing noise while retaining essential information from practical magnetic anomaly *** particular,practical applications suggest that 2D ICEEMDAN can extract trend signals more accurately than the *** conclusion,as a potential tool for multi-scale decomposition,the 2D ICEEMDAN is versatile in processing and analyzing 2D geophysical and geodetic data.

关键词： 2D ICEEMDAN Mode mixing effect Magnetic anomaly Denoising Improved soft thresholding

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Contemporary Asymmetric Genetic Introgression Between Two Pelophylax Species in Shanghai

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Asian Herpetological Research 2024年第1期15卷 1-11页

作者： Xu WEI Wenli LIU Gang WANG Rui MA Meiling HUANG Jiaxin ZHENG Tingwei DONG changqing yuan Shunqi BO Xiao yuan Ben LI Shuo MA Qu YUE Youzhong DING Zhenghuan WANG School of Life Sciences East China Normal UniversityShanghai 200241China Shanghai Landscaping and City Appearance Administrative Bureau Shanghai 200041China State Key Laboratory of Estuarine and Coastal Research East China Normal UniversityShanghai 200241China Shanghai Key Lab for Urban Ecological Processes and Eco-Restoration East China Normal UniversityShanghai 200241China Yangtze Delta Estuarine Wetland Ecosystem Observation and Research Station Ministry of Education&Shanghai Science and Technology CommitteeShanghai 202162China

Human disturbances are considered to break reproduction barriers among *** increases in hybridization events have been reported among a large number of taxonomic groups in anthropogenic environments,providing novel insights into species evolution mechanisms and conservation management in the *** Eastern Golden Frog(Pelophylax plancyi)and BlackSpotted Frog(***)are two sympatric anuran species with a long history of mitochondrial genome introgression in highly urbanized continental East ***,there is only limited understanding of the pattern of their contemporary hybridization and factors influencing their interspecific relationship under anthropogenic ***,interspecific hybridization between *** and *** at the population level was investigated in *** except two haplotypes obtained from both species in Shanghai were mixed together,and located in the introgression clade,implying multiple ancient mitochondrial introgression events occurred in the populations of our study *** genetic introgression was detected by microsatellite markers,with 0.7%of *** and 14.6%of *** identified as contemporary admixed *** with the trend of population density,higher genetic diversity of neutral microsatellite loci was found in the more abundant ***;however,variation in mitochondrial(Cyt-b)and nuclear(POMC)genes was higher in relatively rare *** population density of *** and number of water patches within local habitats were significantly positively correlated with both occurrences and proportions of admixed individuals in the populations of *** and *** the prevalent transformation of habitats in urbanized areas,these results imply that a high population density in isolated artificially altered habitats is likely to increase interspecific ***,population monitoring and improveme

关键词： anthropogenic disturbances interspecific hybridization Pelophylax species abundance urban landscape urbanization

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Ultrastructure of neuronal-like cells differentiated from adult adipose-derived stromal cells

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Neural Regeneration Research 2010年第19期5卷 1456-1463页

作者： changqing Ye Xiaodong yuan Hui Liu Yanan Cai Department of Neurology Kailuan General Hospital North China Coal Medical University Tangshan 063000 Hebei Province China

β-mercaptoethanol induces in vitro adult adipose-derived stromal cells （ADSCs） to differentiate into neurons. However, the ultrastructural features of the differentiated neuronal-like cells remain unknown. In the present study, inverted phase contrast microscopy was utilized to observe β-mercaptoethanol-induced differentiation of neuronal-like cells from human ADSCs, and immunocytochemistry and real-time polymerase chain reaction were employed to detect expression of a neural stem cells marker （nestin）, a neuronal marker （neuron-specific enolase）, and a glial marker （glial fibrillary acidic protein）. In addition, ultrastructure of neuronal-like cells was observed by transmission election microscopy. Results revealed highest expression rate of nestin and neuron-specific enolase at 3 and 5 hours following induced differentiation; cells in the 5-hour induction group exhibited a neuronal-specific structure, i.e., Nissl bodies. However, when induction solution was replaced by complete culture medium after 8-hour induction, the differentiated cells reverted to the fibroblast-like morphology from day 1. These results demonstrate that β-mercaptoethanol-induced ADSCs induced differentiation into neural stem cells, followed by morphology of neuronal-like cells. However, this differentiation state was not stable.

关键词： human adipose-derived stromal cells β-mercaptoethanol induction in vitro differentiation ultrastructure neural stem cells neural regeneration

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Effect of annealing temperatures on dynamic impact mechanical properties of high manganese TWIP steel

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Baosteel Technical Research 2008年第1期2卷 37-40页

作者： Liang Gaofei Lin changqing Fang yuan Advanced Technology Div. Baosteel Research Institute Baoshan Iron ＆ Steel Co. Ltd. Shanghai 201900 China

Results presented in this paper contribute to the investigation of the effect of annealing temperatures ranging from 800 to 1000 ℃ on the dynamic impact mechanical properties of high manganese TWIP steel. The properties were measured by using an instrumented Charpy impact tester. The impact absorbing energy initially increases with the annealing temperature, climaxes at 900 ℃, and then decreases. The dynamic crack extension resistance curve indicates that the crack initiation force decreases with the annealing temperature, and the steel annealed at 900 ℃ has the best ability against crack expansion

关键词： TWIP steel dynamics mechanical properties annealing

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Net effect of air pollution controls on health risk in the Beijing-Tianjin-Hebei region during the 2022 winter Olympics and Paralympics

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Journal of Environmental Sciences 2024年第1期135卷 560-569页

作者： changqing Lin Peter K.K.Louie Alexis K.H.Lau Jimmy C.H.Fung Zibing yuan Minghui Tao Xuguo Zhang Md.Shakhaoat Hossain Chengcai Li Xiang Qian Lao Division of Environment and Sustainability The Hong Kong University of Science and TechnologyHong KongChina Environmental Protection Department Hong Kong Government SARHong KongChina Department of Civil and Environmental Engineering The Hong Kong University of Science and TechnologyHong KongChina Guangdong-Hongkong-Macao Joint Laboratory of Collaborative Innovation for Environmental Quality The Hong Kong University of Science and TechnologyHong KongChina Department of Mathematics The Hong Kong University of Science and TechnologyHong KongChina School of Environment and Energy South China University of TechnologyGuangzhou 510006China Hubei Key Laboratory of Critical Zone Evolution School of Geography and Information EngineeringChina University of GeosciencesWuhan 430074China Department of Public Health and Informatics Jahangirnagar UniversityDhaka 1342Bangladesh Department of Atmospheric and Oceanic Sciences School of PhysicsPeking UniversityBeijing 100871China Jockey Club School of Public Health and Primary Care The Chinese University of Hong KongHong KongChina

Due to the non-linearity in ozone(O_(3))formation,reducing the emission of nitrogen oxides(NO_(x))may increase O_(3) *** the counteractive O_(3) response to NO_(x) reduction,overall impact of air pollution controls can be ambiguous when the assessments focus on the changes in pollutant *** this study,a risk-based method was used to gauge the net effect of air pollution controls on mortality risk in the Beijing–Tianjin–Hebei(BTH)region during the 2022 Winter Olympics and Paralympics(WOP).This mega-event presents a unique opportunity to investigate the efficacy of deep cuts in pollutant *** show that O_(3) concentrations greatly increased as nitrogen dioxide(NO_(2))concentrations decreased in the *** to the active photochemical formations,O_(3) became the dominant pollutant that affected human health during the *** the substantial O_(3) increases,the health benefits of NO_(2) reductions overwhelmed the adverse health effects of O_(3) increases in most regions of the BTH(at 81 out of 112 stations).After considering the impacts of particulate matter,the integrated health risk of air pollution mixtures declined almost everywhere in the *** results underscore the great necessity of changing the assessment paradigm of pollution control from using concentration-based methods to using risk-based *** with the carbon neutrality policy,stringent control of NO_(x)emission from combustion sources is a promising way to achieve synergistic control solutions for air pollution and climate change.

关键词： Ozone Nitrogen dioxide Health risk Carbon neutrality Mega-events

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POP3和用户访问的授权检查

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计算机工程与应用 2000年第1期36卷 134-136页

作者：袁常青张瑛山东省计算中心济南250014 济南市电信局市话交换维护中心济南250001

该文介绍了ＰＯＰ３邮局管理协议的用户授权检查过程，介绍了该检查过程在开发基于Ｗｅｂ的ＩＮＴＥＲＮＥＴ／ＩＮＴＲＡＮＥＴ应用时的应用，并给出了用ＶＢ、Ｊａｖａ和Ｐｅｒｌ编写的例子。

关键词： POP3 授权访问电子邮件用户访问

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ROBUST ATTITUDE TRACKING CONTROL OF A FLEXIBLE MULTI-BODY SPACECRAFT

ROBUST ATTITUDE TRACKING CONTROL OF A FLEXIBLE MULTI-BODY SP...

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中国力学学会学术大会'2005

作者： yuan changqing Li Junfeng (School of Aerospace, Tsinghua University, Beijing 100084, China)

This paper deals with attitude tracking problems of a flexible multi-body spacecraft in the presence of model uncertainties and external disturbances. Robust control system with nonlinear dynamic inversion structure is synthesized for accurate tracking. Then a comparison is made with PD *** spacecraft consists of the main body, a flexible beam ,a large mobile antenna etc. To track the target spacecraft with the orbit, the mobile antennas have to move in a wide range,which disturbing the spacecraft attitude. Due to inherent nonlinearity of attitude dynamics, tracking large and rapid maneuvers is a complex undertaking. Furthermore, external disturbances and vibration of the flexible beam influence tracking performance of the antennas.

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人工平动点附近混合推进航天器编队滑模控制保持

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北京航空航天大学学报 2023年第5期49卷 1222-1230页

作者：贺京九袁长清龚胜平赵磊空军航空大学航空作战勤务学院长春130011 空军航空大学航空基础学院长春130011 北京航空航天大学宇航学院北京100191

针对近距离航天器编队在日地系人工L1点附近的飞行控制问题,提出一种将太阳帆推进技术与库仑力编队技术相结合的混合推进控制方法。通过控制从航天器太阳帆相对于主航天器的姿态角调整主从间光压力差,同时与主从间库仑力相配合,既解决... 详细信息

针对近距离航天器编队在日地系人工L1点附近的飞行控制问题,提出一种将太阳帆推进技术与库仑力编队技术相结合的混合推进控制方法。通过控制从航天器太阳帆相对于主航天器的姿态角调整主从间光压力差,同时与主从间库仑力相配合,既解决仅依靠太阳帆控制而存在的欠驱动问题,又改善了库仑编队的可控性。以太阳帆圆形限制性三体问题(SSCRTBP)模型为基础,给出共线人工平动点位置的计算方法,并构造主航天器运行轨道;引入航天器间库仑力,推导出混合推进编队相对运动方程;设计了固定时间滑模控制策略,以从航天器太阳帆的2个姿态角和主从间电荷积为控制量,对编队构型进行控制,将其与LQR控制策略对比,仿真结果表明:固定时间滑模控制策略在控制精度、所需时间、能量消耗等方面均优于LQR控制策略。在时长3年的任务中,编队仅用23天就展开完毕,保持阶段基线相对误差小于1%,其他两轴误差在厘米量级,整个过程无工质消耗,对于今后开展长期深空探测任务具有重要意义。

关键词：平动点编队太阳帆推进库仑力编队混合推进滑模控制 LQR控制

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径向两星库仑编队队形保持自适应控制研究

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空间控制技术与应用 2017年第3期43卷 28-33,53页

作者：施强袁长清吴立尧空军航空大学飞行器与动力系长春吉林130022

研究地球同步轨道处径向两星库仑编队队形保持的自适应控制问题.建立了双星库仑编队在地球同步轨道处径向两星库仑编队动力学模型.基于建立的非线性化动力学模型,同时考虑到外部扰动和动力学模型误差等因素,设计径向两星库仑编队在地球... 详细信息

研究地球同步轨道处径向两星库仑编队队形保持的自适应控制问题.建立了双星库仑编队在地球同步轨道处径向两星库仑编队动力学模型.基于建立的非线性化动力学模型,同时考虑到外部扰动和动力学模型误差等因素,设计径向两星库仑编队在地球同步轨道处的构型保持自适应控制律,并利用Lyapnuov稳定性理论证明系统的闭环稳定性.最后进行数值仿真,并与传统PID控制进行了比较.仿真结果表明提出的自适应控制律响应速度快,稳定性好,编队构型能够收敛到期望值,控制性能明显优于PID控制.

关键词：库仑编队地球同步轨道构型保持自适应控制

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公路环境生态经济损失评估及思考

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资源环境与工程 2009年第F9期23卷 137-138,160页

作者：原长青四川省交通厅公路规划勘察设计研究院通川岩土公司四川成都610041

"5.12"汶川地震发生后,公路交通系统遭受了巨大的环境生态经济损失,而公路作为人们赖以生存发展的必要条件,尤其是作为生命线工程的重要组成部分,如何进行相关的环境损失经济评估是目前面临的主要问题。本文综述了公路发展的重要性,列... 详细信息

"5.12"汶川地震发生后,公路交通系统遭受了巨大的环境生态经济损失,而公路作为人们赖以生存发展的必要条件,尤其是作为生命线工程的重要组成部分,如何进行相关的环境损失经济评估是目前面临的主要问题。本文综述了公路发展的重要性,列举了有关公路工程环境经济损失的风险影响的因素,阐述了工程环境损失评估方法步骤,提出建立恶劣天气、突发事件等高速公路应急机制,为公路工程项目管理的正确决策提供支持。

关键词： “5.12”汶川地震公路环境生态经济损失评估

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