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Remote sensing imagery in vegetation mapping: a review

Journal of Plant Ecology 2008年第1期1卷 9-23页

作者： yichun xie Zongyao Sha Mei Yu Department of Geography and Geology Eastern Michigan UniversityYpsilantiMI 48197USA International Software School Wuhan UniversityWuhanHubei Province 430079China Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China

Aims Mapping vegetation through remotely sensed images involves various considerations,processes and *** availability of remotely sensed images due to the rapid advancement of remote sensing technology expands the horizon of our choices of imagery *** sources of imagery are known for their differences in spectral,spatial,radioactive and temporal characteristics and thus are suitable for different purposes of vegetation ***,it needs to develop a vegetation classification at first for classifying and mapping vegetation cover from remote sensed images either at a community level or species ***,correlations of the vegetation types(communities or species)within this classification system with discernible spectral characteristics of remote sensed imagery have to be *** spectral classes of the imagery are finally translated into the vegetation types in the image interpretation process,which is also called image *** paper presents an overview of how to use remote sensing imagery to classify and map vegetation *** Specifically,this paper focuses on the comparisons of popular remote sensing sensors,commonly adopted image processing methods and prevailing classification accuracy *** findings The basic concepts,available imagery sources and classification techniques of remote sensing imagery related to vegetation mapping were introduced,analyzed and *** advantages and limitations of using remote sensing imagery for vegetation cover mapping were provided to iterate the importance of thorough understanding of the related concepts and careful design of the technical procedures,which can be utilized to study vegetation cover from remote sensed images.

关键词： vegetation mapping remote sensing sensors image processing image classification

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Design of Service-Oriented Architecture for Spatial Data Integration and Its Application in Building Web-based GIS Systems

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Geo-Spatial Information Science 2010年第1期13卷 8-15页

作者： SHA Zongyao xie yichun International School of Software Wuhan University 129 Luoyu Road Wuhan 430079 China

In this paper we propose a service-oriented architecture for spatial data integration (SOA-SDI) in the context of a large number of available spatial data sources that are physically sitting at different places, and develop web-based GIS systems based on SOA-SDI, allowing client applications to pull in, analyze and present spatial data from those available spatial data sources. The proposed architecture logically includes 4 layers or components; they are layer of multiple data provider services, layer of data in-tegration, layer of backend services, and front-end graphical user interface (GUI) for spatial data presentation. On the basis of the 4-layered SOA-SDI framework, WebGIS applications can be quickly deployed, which proves that SOA-SDI has the potential to reduce the input of software development and shorten the development period.

关键词： spatial data integration web-based GIS service-oriented architecture software

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三维激光扫描应用在油气管道变形测量

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城市勘测 2024年第4期 150-153页

作者：郑瀚谢义春王鹏孙冀鹏广州市吉华勘测股份有限公司广东广州511430 杭州同谦信息技术有限公司浙江杭州310019

油气管道变形测量是为了保障油气管道建设与运维全寿命周期中工程安全极其重要的一个技术环节。为了获取高精度、全方位、完整的油气管道三维数据,采用三维激光扫描技术,解决了常规测量未能全覆盖被测实体的问题。把油气管道物体表面的... 详细信息

油气管道变形测量是为了保障油气管道建设与运维全寿命周期中工程安全极其重要的一个技术环节。为了获取高精度、全方位、完整的油气管道三维数据,采用三维激光扫描技术,解决了常规测量未能全覆盖被测实体的问题。把油气管道物体表面的三维坐标数据进行分析和对比,真实反映所测物体的变形情况。本文依据油气管道变形测量项目,结合三维激光扫描技术的生产过程,分析该技术的全面性、可靠性和优势性。

关键词：三维激光扫描变形测量精度油气管道点云

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Cytotoxicity and autophagy induction by graphene quantum dots with different functional groups

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Journal of Environmental Sciences 2019年第3期31卷 198-209页

作者： yichun xie Bin Wan Yu Yang Xuejing Cui Yan Xin Liang-Hong Guo State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental Sciences Chinese Academy of Sciences University of Chinese Academy of Sciences CAS Key Laboratory for Biomedical Effects of Nanomaterials and Nanosafety National Center for Nanoscience and Technology of China Institute of Environment and Health Jianghan University

Graphene quantum dots(GQDs) possess great potential in various applications due to their superior physicochemical properties and wide array of available surface ***, the toxicity of GQDs has not been systematically assessed, thus hindered their further development; especially, the risk of surface modifications of GQDs is largely unknown. In this study, we employed a lung carcinoma A549 cells as the model to investigate the cytotoxicity and autophagy induction of three types GQDs, including cGQDs(COOH-GQDs), hGQDs(OH-GQDs), and aGQDs(NH_2-GQDs). The results showed hGQDs was the most toxic, as significant cell death was induced at the concentration of 100 μg/mL,determining by WST-1 assay as well as Annexin-V-FITC/PI apoptosis analysis, whereas cGQDs and aGQDs were non-cytotoxic within the measured concentration. Autophagy detection was performed by TEM examination, LC3 fluorescence tracking, and Westernblot. Both aGQDs and hGQDs induced cellular autophagy to various degrees except for cGQDs. Further analysis on autophagy pathways indicated all GQDs significantly activated p-p38 MAPK; p-ERK1/2 was inhibited by aGQDs and hGQDs but activated by c GQDs. p-JNK was inhibited by aGQDs and c GQDs, while activated by hGQDs. Simultaneously, Akt was activated by hGQDs but inhibited by aGQDs. Inhibition of autophagy by 3-MA significantly increased the cytotoxicity of GQDs, suggesting that autophagy played a protective role against the toxicity of GQDs. In conclusion, c GQDs showed excellent biocompatibility and may be considered for biological applications. Autophagy induction may be included in the health risk assessment of GQDs as it reflects the stress status which may eventually lead to diseases.

关键词： Graphene quantum dots Cytotoxicity Autophagy Surface functional group

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Assessing the impacts of human activities and climate variations on grassland productivity by partial least squares structural equation modeling(PLS-SEM)

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Journal of Arid Land 2017年第4期9卷 473-488页

作者： SHA Zongyao xie yichun TAN Xicheng BAI Yongfei LI Jonathan LIU Xuefeng International Software School Wuhan University Department of Geography and Geology Eastern Michigan University Institute of Botany Chinese Academy of Sciences Department of Geography & Environmental Management University of Waterloo School of Communication and Information Engineering Shanghai University

The cause-effect associations between geographical phenomena are an important focus in ecological research. Recent studies in structural equation modeling（SEM） demonstrated the potential for analyzing such associations. We applied the variance-based partial least squares SEM（PLS-SEM） and geographically-weighted regression（GWR） modeling to assess the human-climate impact on grassland productivity represented by above-ground biomass（AGB）. The human and climate factors and their interaction were taken to explain the AGB variance by a PLS-SEM developed for the grassland ecosystem in Inner Mongolia, China. Results indicated that 65.5% of the AGB variance could be explained by the human and climate factors and their interaction. The case study showed that the human and climate factors imposed a significant and negative impact on the AGB and that their interaction alleviated to some extent the threat from the intensified human-climate pressure. The alleviation may be attributable to vegetation adaptation to high human-climate stresses, to human adaptation to climate conditions or/and to recent vegetation restoration programs in the highly degraded areas. Furthermore, the AGB response to the human and climate factors modeled by GWR exhibited significant spatial variations. This study demonstrated that the combination of PLS-SEM and GWR model is feasible to investigate the cause-effect relation in socio-ecological systems.

关键词： spatial modeling human-natural interaction grazing urbanization road network

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郁闭度对柳杉人工林下红豆树幼树生长和矿质营养的影响

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贵州科学 2024年第3期42卷 23-27页

作者：姚华忆谢义春王碧艳韦小丽贵州省国有扎佐林场贵州贵阳550201 贵州大学林学院贵州贵阳550025

为探讨红豆树在不同郁闭度林冠下造林的效果,筛选林下更新补植红豆树的最佳郁闭度,在现有柳杉人工林中通过调控设置3个郁闭度L_(1)(0.6)、L_(2)(0.5)、L_(3)(0.4),补植2年生红豆树幼苗,测定其株高、地径、生物量等生长指标和叶片氮、磷... 详细信息

为探讨红豆树在不同郁闭度林冠下造林的效果,筛选林下更新补植红豆树的最佳郁闭度,在现有柳杉人工林中通过调控设置3个郁闭度L_(1)(0.6)、L_(2)(0.5)、L_(3)(0.4),补植2年生红豆树幼苗,测定其株高、地径、生物量等生长指标和叶片氮、磷、钾等矿质营养含量指标,通过隶属函数进行综合评价。结果表明,不同郁闭度处理下红豆树株高、地径生长差异不显著(P>0.05),株高生长最好的是郁闭度0.5,分别比郁闭度0.6、0.4提高19.27%和11.52%;地径生长最好的是郁闭度0.5,比表现最差的郁闭度0.4高0.06%;不同郁闭度处理,红豆树根、茎、叶、总生物量差异显著(PL_(1)>L_(3),可以认为2年生的红豆树在柳杉林下栽植适宜的郁闭度为0.5。

关键词：郁闭度红豆树柳杉人工林生长矿质营养林下更新

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A comparative analysis of changes in the phasing of temperature and satellite-derived greenness at northern latitudes

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Journal of Geographical Sciences 2013年第1期23卷 57-66页

作者： MA Ting ZHOU Chenghu PEI Tao xie yichun State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources Research CAS Seijing 100101 China Department of Geography and Geology Eastern Michigan University Ypsilanti MI 48917 USA

Plant growth at northern latitudes is highly responsive to the climatic changes that have occurred over recent decades. However, the sensitivity of the phasing of the seasonal cycle of terrestrial ecosystems to a changing environment remains less widely understood. We present an investigation and comparative study of large-scale changes in seasonal cy- cling of both land surface temperature and plant growth. Our results have shown trends in- dicating a marked increased towards overall plant productivity by -3% from 1982 to 2005, reduced trends in seasonal variation at low-mid latitudes by ~2%, increased trends in sea- sonal variations at mid-high latitudes by ~7%, and an earlier phase in northern terrestrial ecosystems （~1.1 days） in parallel with changes in the phasing of surface temperatures at northern latitudes over the 24 years in this study. These shifts in annual cycles of terrestrial vegetation appear to have a distinct geographical zonality and are dependent upon latitudinal changes in climatic variables. More conspicuous changes in overall vegetation productivity and the seasonal phase of ecosystems have been observed in Eurasia compared to North America, largely because of a more rapid rise in temperature. Our results state that changing climate boosts plant growth at northern latitudes, but also alters the phase and seasonal variations of the annual cycle of terrestrial ecosystems.

关键词： land surface temperature plant phenoiogy NDVI climate changes northern latitudes

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UAVs as remote sensing platforms in plant ecology:review of applications and challenges

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Journal of Plant Ecology 2021年第6期14卷 1003-1023页

作者： Zhongyu Sun Xiaonian Wang Zhihui Wang Long Yang yichun xie Yuhui Huang Guangdong Open Laboratory of Geospatial Information Technology and Application Guangzhou Institute of GeographyGuangdong Academy of SciencesGuangzhou 510070China School of Geographical Sciences South China Normal UniversityGuangzhou 510631China Department of Geography and Geology Eastern Michigan UniversityYpsilantiMI 48197USA Guangdong Provincial Key Laboratory of Silviculture Protection and UtilizationGuangdong Academy of ForestryGuangzhou 510520China

Aims Unmanned aerial vehicles(UAVs),***,have recently emerged as cost-effective and flexible tools for acquiring remote sensing data with fine spatial and temporal *** provides a new method and opportunity for plant ecologists to study issues from individual to regional ***,as a new method,UAVs remote sensing applications in plant ecology are still *** needs of plant ecology research and the application development of UAVs remote sensing should be better *** This report provides a comprehensive review of UAV-based remote sensing applications in plant ecology to synthesize prospects of applying drones to advance plant ecology *** Findings Of the 400 references,59%were published in remote sensing journals rather than in plant ecology journals,reflecting a substantial gap between the interests of remote sensing experts and plant *** of the studies focused on UAV remote sensing’s technical aspects,such as data processing and remote sensing inversion,with little attention on answering ecological *** were 61%of studies involved community-scale *** and multispectral cameras were the most used sensors(75%).More ecologically meaningful parameters can be extracted from UAV data to better understand the canopy surface irregularity and community heterogeneity,identify geometrical characteristics of canopy gaps and construct canopy chemical assemblies from living vegetation *** cooperation between plant ecologists and remote sensing experts is needed to promote UAV remote sensing in advancing plant ecology research.

关键词： UAVs drones unmanned aircraft systems(UASs) plant ecology species identification community function

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Investigating long-term trends of climate change and their spatial variations caused by regional and local environments through data mining

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Journal of Geographical Sciences 2018年第6期28卷 802-818页

作者： xie yichun ZHANG Yang LAN Hai MAO Lishen ZENG Shi CHEN Yulu Institute for Geospatial Research and Education Eastern Michigan UniversityYpsilantiMichigan 48197 USA Guangzhou Institute of Geography Guangzhou 510070China Department of Computer Science Indiana UniversityBloomingtonIndiana 47405USA Department of Computer Science New York UniversityNY 10012USA Center for Advanced Spatial Analysis University College LondonLondon WCIE 6BTU

Climate change is a global phenomenon but is modified by regional and local environmental ***,climate change exhibits remarkable cyclical oscillations and disturbances,which often mask and distort the long-term trends of climate change we would like to *** by recent advancements in data mining,we experimented with empirical mode decomposition(EMD)technique to extract long-term change trends from climate *** applied GIS elevation model to construct 3 D EMD trend surface to visualize spatial variations of climate change over regions and *** then computed various time-series similarity measures and plot them to examine spatial patterns across meteorological *** conducted a case study in Inner Mongolia based on daily records of precipitation and temperature at 45 meteorological stations from 1959 to *** EMD curves effectively illustrated the long-term trends of climate *** EMD 3 D surfaces revealed regional variations of climate change,while the EMD similarity plots disclosed cross-station *** brief,the change trends of temperature were significantly different from those of *** regional patterns and local disturbances of the changes in both temperature and precipitation were *** trends of change were modified by regional and local topographies and land covers.

关键词： climate change empirical mode decomposition Inner Mongolia similarity plot trend surface

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河口最大浑浊带研究的回顾与展望

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科学通报 2021年第18期66卷 2328-2342页

作者：王重洋周成虎陈水森 yichun xie 李丹杨骥周霞李勇王丹妮刘杨晓月广东省科学院广州地理研究所广东省地理空间信息技术与应用公共实验室广东省遥感与地理信息系统应用重点实验室广东省遥感大数据应用工程技术研究中心广州510070 中国科学院地理科学与资源研究所资源与环境信息系统国家重点实验室北京100101 南方海洋科学与工程广东省实验室(广州) 广州511458 Institute for Geospatial Research&Education Eastern Michigan UniversityYpsilantiMI 48197USA 中山大学新华学院资源与城乡规划系广州510520

最大浑浊带是河口近岸泥沙含量显著高于上下游,并在一定范围内有规律迁移的浑浊水体,是河流入海泥沙输移过程中的特有现象.它显著体现了河流、海洋及物质能量的耦合作用,其发展动态、研究进展备受关注.本文通过回顾国内外河口最大浑浊... 详细信息

最大浑浊带是河口近岸泥沙含量显著高于上下游,并在一定范围内有规律迁移的浑浊水体,是河流入海泥沙输移过程中的特有现象.它显著体现了河流、海洋及物质能量的耦合作用,其发展动态、研究进展备受关注.本文通过回顾国内外河口最大浑浊带80多年来的研究现状和历程,总结经验、展望未来.既有研究已对河口最大浑浊带的泥沙含量、物质来源及组成等基本特征进行了较为全面的总结,认识到不同类型河口最大浑浊带的形成发育存在不同的主导动力过程和主控影响因素;此外,河口最大浑浊带在中短尺度上的时空变化也得到了比较充分的分析和讨论.相关研究在多方面都取得了瞩目的成果和进展,具有重要的科学价值与现实意义.但是,分析认为仍亟待继续开展并进一步加强最大浑浊带的精准定量识别方法研究、空间立体分布整体特性研究,特别是人类活动加剧和全球自然环境显著变化影响下的长期时空动态特征研究,以促进对河口最大浑浊带现象及其时空演变规律和趋势更加全面、更加深刻的认识和理解,助力社会经济和自然环境健康可持续发展.

关键词：河口最大浑浊带形成机制时空变化

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