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土壤中重金属是有害的,其迁移和累积会严重威胁生态环境安全和人类健康。砷(As)具有高神经毒性和致畸性。人类活动,例如采矿和工业生产会导致大量As释放到土壤中。快速准确确定土壤中As浓度对As污染评估至关重要。传统的重金属调查方法旨在对野外采集的土壤样品进行化学性质测试,费事费力、成本高。高光谱遥感具有高光谱分辨率、宽波段范围和连续光谱信息等特点,已广泛用于土壤重金属浓度的估算。然而,现存的基于高光谱数据的土壤重金属浓度估算模型忽视了土壤光谱和重金属浓度之间的空间非稳态。基于此,来自首都师范大学的一组研究团队以北京东北部地区(40°10′0″-40°15′30″ N,116°58′4″-117°5′4″ E)为例,基于实验室测得的光谱数据(ASD FieldSpec 4光谱仪),结合地理加权回归(GWR)和XGBoost算法提出了一种新的模型(GW-XGBoost模型)来估算土壤重金属浓度。并评估了所提出模型的有效性。研究区和采样位置。As浓度估算过程流程图。【结果】As和光谱的相关图。阴影快表示主要化学吸收范围。As浓度实测值与预测值关系散点图。As浓度实测值与预测值拟合比较图。【结论】估算模型选择的光谱波段与表面含有能与As形成复合物的官能团的光谱活性物质的吸收效应有关。构建模型时考虑该吸收机制可以有效降低高光谱数据的冗余。GW-XGBoost模型不仅考虑了As浓度和光谱关系的异质性,也考虑了其复杂相关性,有效提高了土壤As浓度估算精度。GW-XGBoost模型可以更准确估算土壤重金属浓度,为利用高光谱技术大尺度监测土壤重金属污染提供技术支持。请点击下方链接,阅读原文:https://mp.weixin.qq.com/s?__biz=MjM5NjE1ODg2NA==&mid=2650316477&idx=1&...
发布时间: 2023 - 02 - 07
浏览次数:4
Ecosystem carbon (CO2 and CH4) fluxes of a Populus dettoides plantationin subtropical China during and post clear-cutting Shenghua Gao a, Jiquan Chen b, Yuxi Tang c, Jing Xie d, Rui Zhang e, Jie Tang c, Xudong Zhang a,*a State Key Laboratory of Tree Genetics and Breeding, Research Institute of Forestry, Chinese Academy of Forestry, Beijing 100091, Chinab Center for Global Change and Earth Observations (CGCEO) and Department of Geography, Michigan State University, East Lansing, MI 48823, USAc Hunan Academy of Forestry, Chang...
发布时间: 2015 - 09 - 15
浏览次数:42
HYPERSPECTRAL REMOTE SENSING FOR DETECTION OF RHIZOCTONIA CROWN AND ROOT ROT IN SUGARBEETGregory J. Reynolds1, Carol E. Windels2, Ian V. MacRae3, and Soizik Laguette4Graduate Student, Professor, Associate Professor, and Assistant Professor, respectively1University of Minnesota, Department of Plant Pathology, St. Paul2University of Minnesota, Department of Plant Pathology and Northwest Research & Outreach Center, Crookston3University of Minnesota, Department of Entomology and Northwest Research & Outreach Center, Crookston4University of North Dakota, Department of Earth System Science a...
发布时间: 2015 - 08 - 11
浏览次数:45
DETECTION OF SUGARCANE AFRICAN STALK BORER ELDANASACCHARINA WALKER (LEPIDOPTERA: PYRALIDAE) USINGHYPERSPECTRAL REMOTE SENSING (SPECTRORADIOMETRY)应用ASD地物光谱仪检测蛀虫ELDANA SACCHARINA(鳞翅目:螟蛾科)对非洲甘蔗茎部的危害程度MOKHELE TA1, AHMED F1 and CONLONG DE2,31School of Environmental Sciences, University of KwaZulu-Natal, Durban, 4041, South Africa2South African Sugarcane Research Institute, Private Bag X02, Mount Edgecombe 4300, South Africa3School of Biological and Conservation Sciences, University of KwaZulu-Natal, Private Bag X01, Scottsville, 3209, South AfricaAbstractThe South African sugar industry i...
发布时间: 2015 - 08 - 06
浏览次数:61
LGR氧化亚氮同位素分析仪测量水中硝酸盐成功案例:Analytical Chemistry 文章:Combining Denitrifying Bacteria and Laser Spectroscopy for Isotopic Analyses (δ15N, δ18O) of Dissolved Nitrate通过反硝化细菌和激光同位素分析仪测定溶解硝酸盐中的δ15N和δ18ODavid X. Soto *†, Geoff Koehler †, and Keith A. Hobson †† Environment Canada, 11 Innovation Boulevard, Saskatoon, Saskatchewan, Canada, S7N 3H5AbstractWe present a novel approach for nitrogen (δ15N) and oxygen (δ18O) isotopic analysis of nitrate in water based on the isotopic analysis of N2O produced from the conversion of NO3– by cultured denitrifying bacteria and off-axis integrated cavity output ...
发布时间: 2015 - 07 - 21
浏览次数:57
Nature 发表文章:In-situ unsaturated zone stable water isotope (2H and 18O) measurements in semi-arid environments using tunable o-axis integrated cavity output spectroscopy科学家应用LGR液态水同位素分析仪在半干旱环境下原位测量不饱和带水中2H和18O同位素比值M. Gaj1,2,  M. Beyer1,  P. Koeniger1,  H. Wanke3,  J. Hamutoko3,  and T. Himmelsbach11 Federal Institue for Geosciences and Natural Resources (BGR), Stilleweg 2, Hannover, Germany2 Chair of Hydrology, Faculty of Environment and Natural Resources, University of Freiburg, Fahnenbergplatz, 79098 Freiburg, Germany3Universit...
发布时间: 2015 - 07 - 07
浏览次数:42
Inter- and intraindividual correlations of background abundances of 2H, 18O and 17O in human urine and implications for DLW measurements科学家应用LGR同位素分析仪测定人体尿液中的2H,18O和17O丰度间的相互作用对DLW测量方法的影响E S F Berman, E L Melanson, T Swibas, S P Snaith and J R SpeakmanBackground/Objectives:The method of choice for measuring total energy expenditure in free-living individuals is the doubly labeled water (DLW) method. This experiment examined the behavior of natural background isotope abundance fluctuations within and between individuals over time to assess possible methods of accounting for varia...
发布时间: 2015 - 07 - 01
浏览次数:33
科学家应用Campbell CPEC200闭路涡动相关系统测量森林碳封存Canada: Forest Carbon SequestrationCampbell Scientific CPEC200 monitors eddy-covariance fluxes in British Columbia forest 文章下载地址:79canada-vancouver-island--CPEC200.pdf4da92e4cbee3e5c7273825cef11d6136.pdf (2.84 MB)
发布时间: 2015 - 05 - 19
浏览次数:47
Field Spectroscopy in the VNIR-SWIR Region to Discriminate between Mediterranean Native Plants and Exotic-Invasive Shrubs Based on Leaf Tannin Content      基于可见光近红外(VNIR)和短波红外(SWIR),科学家应用ASD地物光谱仪测量叶片单宁的含量,从而区分地中海附近海岸的本土植物和外来入侵灌木。Authors: Jan Rudolf Karl Lehmann, André Große-Stoltenberg, Meike Römer and Jens OldelandAbstract: The invasive shrub, Acacia longifolia, native to southeastern Australia, has a negative impact on vegetation and ecosystem functioning in Portuguese dune ecosystems. In order to spectrally discriminate A. longifoliafrom oth...
发布时间: 2015 - 05 - 12
浏览次数:121
科学家应用LGR氨气分析仪快速原位机载测量空气中氨气的含量Fast in situ Airborne Measurement of AmmoniaUsing a Mid-Infrared Off-Axis ICOS Spectrometer科学家应用LGR氨气分析仪快速原位机载测量空气中氨气的含量,这可以帮助我们更好的分析大气的成分和气溶胶的组成,具有深远的意义。J. Brian Leen,†,* Xiao-Ying Yu,‡,* Manish Gupta,† Douglas S. Baer,† John M. Hubbe,‡ Celine D.Kluzek, ‡ Jason M. Tomlinson,‡ and Mike R. Hubbell II‡†Los Gatos Research Inc., 67 E. Evelyn Ave, Suite 3, Mountain View, CA 94041‡Pacific Northwest National Laboratory, 902 Battelle Boulevard, Richland, WA 99352ABSTRACT:A new ammonia (NH3) analyzer was developed based on off-axis integrated cavity output spectroscopy...
发布时间: 2015 - 03 - 17
浏览次数:42
The relative role of soil type and tree cover on water storageand transmission in northern headwater catchments科学家应用LGR液态水同位素分析仪在北部水源集中区域监测土壤类型与植被覆盖类型对水的存储和传输的影响Josie Geris,1* Doerthe Tetzlaff,1 Jeffrey McDonnell1,2 and Chris Soulsby11 Northern Rivers Institute, School of Geosciences, University of Aberdeen, Scotland, UK2 Global Institute for Water Security, National Hydrology Research Centre, University of Saskatchewan, Saskatoon, Canada Abstract:Soil water storage and stable isotopes dynamics were investigated in dominant soil–vegetation assemblages of a wet nor...
发布时间: 2015 - 02 - 26
浏览次数:42
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