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Journal of Geographical Sciences 2024年第6期34卷 1065-1082页

作者：任嘉义杨俊于文博丛楠肖向明夏建红李雪铭 School of Humanities and Law Northeastern UniversityShenyang 110169China Human Settlements Research Center Liaoning Normal UniversityDalian 116029LiaoningChina Jangho Architecture College Northeastern UniversityShenyang 110169China Lhasa Plateau Ecosystem Research Station Institute of Geographic Sciences and Natural Resources ResearchCASBeijing 100101China Department of Microbiology and Plant Biology Center for Earth Observation and ModelingUniversity of OklahomaNormanOK 73019USA School of Earth and Planetary Sciences(EPS) Curtin UniversityPerth 65630Australia

Many cities face heat wave(HW) events, combined with the existent surface urban heat island(SUHI) effects. This places pressure on human settlements and sustainable development. However, few studies have investigated the SUHI effects from the perspective of HWs. In this study, the summer HWs in Beijing from 2001 to 2021 were calculated, and the evolution of HWs and SUHIs was quantitatively analyzed based on the dynamic nature of the urban-rural boundary. Beijing experienced 27 HWs in the 21 years, including 10 instances in June, four in July, and 13 in August. The SUHI varied during HWs, between 2–3℃ in most years. The highest SUHI occurred in 2019, reaching 3.99℃ and covering the largest area(10,887 km^(2)). The fluctuation in HWs and SUHIs generally displayed the same spatiotemporal pattern, and HWs amplified the SUHIs to a certain extent, with the highest correlation coefficient being 0.44. Additionally, impervious surfaces and cropland contributed most to SUHIs,and night light enhanced SUHIs. Observing the co-evolution of HWs and SUHIs will be helpful for ecological maintenance and urban infrastructure optimization and provide theoretical support for reducing heat risk and improving the human settlement environment.

关键词： heat wave surface urban heat island interactive Self-organization algorithm centroid migration Beijing

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Successful resuscitation after fatal carbon dioxide embolism during laparoscopic nephrectomy

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Chinese Medical Journal 2014年第15期127卷 2863-2864页

作者： Yu Xin Fang xiao Fang xiangming Department of Anaesthesiology the First Affiliated Hospital of Zhejiang University Hangzhou Zhejiang 310012 China

Laparoscopic nephrectomy （LN） is a less invasive surgical option for patients with renal ***,it may be complicated with disastrous CO2 embolism,which is rare but a life-threatening ***,we present a case of lethal CO2 embolism during ***,the complication was detected early and managed *** case and literature review all revealed that gas embolism must be considered as a possible cause of sudden cardiocirculatory failure during LN;rapid diagnosis and definitive intervention can decrease fatality from such an *** mechanisms of CO2 embolism and the potential ways of handling such an event are also ***：laparoscopic nephrectomy; gas embolism; transesophageal echocardiography

关键词： laparoscopic nephrectomy gas embolism transesophageal echocardiography

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Mapping paddy rice distribution using multi-temporal Landsat imagery in the Sanjiang Plain, northeast China

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Frontiers of Earth Science 2016年第1期10卷 49-62页

作者： Cui JIN xiangming xiao Jinwei DONG Yuanwei QIN Zongming WANG Department of Microbiology and Plant Biology Center for Spatial Analysis University of Oklahoma Norman OK 73019 USA Institute of Biodiversity Sciences Fudan University Shanghai 200433 China Northeast Institute of Geography and Agricultural Ecology Chinese Academy of Sciences Changchun 130102 China

Information of paddy rice distribution is essential for food production and methane emission calculation. Phenology-based algorithms have been uti- lized in the mapping of paddy rice fields by identifying the unique flooding and seedling transplanting phases using multi-temporal moderate resolution （500m to 1 km） images. In this study, we developed simple algorithms to identify paddy rice at a fine resolution at the regional scale using multi-temporal Landsat imagery. Sixteen Landsat images from 2010-2012 were used to generate the 30 m paddy rice map in the Sanjiang Plain, northeast China-one of the major paddy rice cultivation regions in China. Three vegetation indices, Normalized Difference Vegetation Index （NDVI）, Enhanced Vegetation Index （EVI）, and Land Surface Water Index （LSWI）, were used to identify rice fields during the flooding/transplanting and ripening phases. The user and producer accuracies of paddy rice on the resultant Landsat-based paddy rice map were 90% and 94%, respectively. The Landsat-based paddy rice map was an improvement over the paddy rice layer on the National Land Cover Dataset, which was generated through visual interpretation and digitalization on the fine-resolution images. The agricultural census data substantially underreported paddy rice area, raising serious concern about its use for studies on food security.

关键词： phenology flooding transplanting ripening,land use

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Mapping rice cropping systems using Landsat-derived Renormalized Index of Normalized Difference Vegetation Index （RNDVI） in the Poyang Lake Region, China

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Frontiers of Earth Science 2016年第2期10卷 303-314页

作者： Peng LI Luguang JIANG Zhiming FENG Sage SHELDON xiangming xiao Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Key Laboratory of Poyang Lake Wetland and Watershed Research Ministry of Education Jiangxi Normal University Nanchang 330022 China Department of Botany and Microbiology Center for Spatial Analysis University of Oklahoma Norman OK 73019 USA

Mapping rice cropping systems with optical imagery in multiple cropping regions is challenging due to cloud contamination and data availability; development of a phenology-based algorithm with a reduced data demand is essential. In this study, the Landsat-derived Renorma- lized Index of Normalized Difference Vegetation Index （RNDVI） was proposed based on two temporal windows in which the NDVI values of single and early （or late） rice display inverse changes, and then applied to discriminate rice cropping systems. The Poyang Lake Region （PLR）, characterized by a typical cropping system of single cropping rice （SCR, or single rice） and double cropping rice （DCR, including early rice and late rice）, was selected as a testing area. The results showed that NDVI data derived from Landsat time-series at eight to sixteen days captures the temporal development of paddy rice. There are two key phenological stages during the overlapping growth period in which the NDVI values of SCR and DCR change inversely, namely the ripening phase of early rice and the growing phase of single rice as well as the ripening stage of single rice and the growing stage of late rice. NDVI derived from scenes in two temporal windows, specifically early August and early October, was used to construct the RNDVI for discriminating rice cropping systems in the polder area of the PLR, China. Comparison with ground truth data indicates high classification accuracy. The RNDVI approach highlights the inverse variations of NDVI values due to the difference of rice growth between two temporal windows. This makes the discrimination of rice cropping systems straightforward as it only needs to distinguish whether the candidate rice typeis in the period of growth （RNDVI 〈 0） or senescence （RNDVI 〉 0）.

关键词： Normalized Difference Vegetation Index(NDVI) Renormalized Index of NDVI (RNDVI) ricecropping systems phenology temporal windows PoyangLake Region (PLR)

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Multiple Cropping Intensity in China Derived from Agro-meteorological Observations and MODIS Data

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Chinese Geographical Science 2014年第2期24卷 205-219页

作者： YAN Huimin xiao xiangming HUANG Heqing LIU Jiyuan CHEN Jingqing BAI Xuehong Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Department of Botany and Microbiology Center for Spatial AnalysisUniversity of Oklahoma

Double-and triple-cropping in a year have played a very important role in meeting the rising need for food in ***,the intensified agricultural practices have significantly altered biogeochemical cycles and soil *** and mapping cropping intensity in China′s agricultural systems are therefore necessary to better estimate carbon,nitrogen and water fluxes within agro-ecosystems on the national *** this study,we investigated the spatial pattern of crop calendar and multiple cropping rotations in China using phenological records from 394 agro-meteorological stations(AMSs)across *** results from the analysis of in situ field observations were used to develop a new algorithm that identifies the spatial distribution of multiple cropping in China from moderate resolution imaging spectroradiometer(MODIS)time series data with a 500 m spatial resolution and an 8-day temporal *** to the MODIS-derived multiple cropping distribution in 2002,the proportion of cropland cultivated with multiple crops reached 34%in ***-cropping accounted for approximately 94.6%and triple-cropping for 5.4%.The results demonstrat that MODIS EVI(Enhanced Vegetation Index)time series data have the capability and potential to delineate the dynamics of double-and triple-cropping *** resultant multiple cropping map could be used to evaluate the impacts of agricultural intensification on biogeochemical cycles.

关键词： agricultural intensification multiple-cropping crop calendar agro-meteorological observation moderate resolution imaging spectroradiometer(MODIS)

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Modeling gross primary production of a temperate grassland ecosystem in Inner Mongolia, China, using MODIS imagery and climate data

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Science China Earth Sciences 2008年第10期51卷 1501-1512页

作者： WU WeiXing WANG ShaoQiang xiao xiangming YU GuiRui FU YuLing HAO YanBin Qianyanzhou Ecological Experimental Station Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Graduate University of Chinese Academy of Sciences Beijing 100049China Institute for the Study of Earth Oceans and SpaceUniversity of New HampshireDurhamNH 03824USA Key Laboratory of Ecosystem Network Observation and Modeling Institute of Geographic Sciences and Natural Resources Re-searchChinese Academy of SciencesBeijing 100101China Laboratory of Quantitative Vegetation Ecology Institute of BotanyChinese Academy of SciencesBeijing 100093China

Carbon fluxes in temperate grassland ecosystems are characterized by large inter-annual variations due to fluctuations in precipitation and land water availability. Since an eddy flux tower has been in operation in the Xilin Gol grassland, which belongs to typical temperate grassland in North China, in this study, observed eddy covariance flux data were used to critically evaluate the biophysical performance of different remote sensing vegetation indices in relation to carbon fluxes. Furthermore, vegetation photosynthesis model (VPM) was introduced to estimate gross primary production (GPP) of the grassland ecosystem for assessing its dependability. As defined by the input variables of VPM, Moderate Resolution Imaging Spectroradimeter (MODIS) and standard data product MOD09A1 were downloaded for calculating enhanced vegetation index (EVI) and land surface water index (LSWI). Measured air temperature (Ta) and photosynthetically active radiation (PAR) data were also included for model simulating. Field CO2 flux data, during the period from May, 2003 to September, 2005, were used to estimate the “observed” GPP (GPP obs) for validation. The seasonal dynamics of GPP predicted from VPM (GPP VPM) was compared quite well (R 2=0.903, N=111, p<0.0001) with the observed GPP. The aggregate GPP VPM for the study period was 641.5 g C·m?2, representing a ～6% over-estimation, compared with GPP obs. Additionally, GPP predicted from other two typical production efficiency model (PEM) represents either higher overestimation or lower underestimation to GPP obs. Results of this study demonstrate that VPM has potential for estimating site-level or regional grassland GPP, and might be an effective tool for scaling-up carbon fluxes.

关键词： GPP eddy covariance remote sensing Xilin Gol

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A hybrid data-driven and mechanism-based method for vehicle trajectory prediction

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Control Theory and Technology 2023年第3期21卷 301-314页

作者： Haoqi Hu xiangming xiao Bin Li Zeyang Zhang Lin Zhang Yanjun Huang Hong Chen School of Automotive Studies Tongji UniversityShanghai 201804China Dongfeng Motor Corporation Wuhan 430000HubeiChina College of Electronics and Information Engineering Tongji UniversityShanghai 201804China

Ensuring the safe and efficient operation of self-driving vehicles relies heavily on accurately predicting their future *** approaches commonly employ an encoder-decoder neural network structure to enhance information extraction during the encoding ***,these methods often neglect the inclusion of road rule constraints during trajectory formulation in the decoding *** paper proposes a novel method that combines neural networks and rule-based constraints in the decoder stage to improve trajectory prediction accuracy while ensuring compliance with vehicle kinematics and road *** approach separates vehicle trajectories into lateral and longitudinal routes and utilizes conditional variational autoencoder(CVAE)to capture trajectory *** evaluation results demonstrate a reduction of 32.4%and 27.6%in the average displacement error(ADE)for predicting the top five and top ten trajectories,respectively,compared to the baseline method.

关键词： Vehicle trajectory prediction Rule knowledge Graph attention network-Conditional variational autoencoder Moving horizon optimization

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The 2012 Flash Drought Threatened US Midwest Agroecosystems

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Chinese Geographical Science 2019年第5期29卷 768-783页

作者： JIN Cui LUO Xue xiao xiangming DONG Jinwei LI Xueming YANG Jun ZHAO Deyu College of Urban and Environment Liaoning Normal UniversityDalian116029China Department of Microbiology and PlantBiology Center for Spatial AnalysisUniversity of OklahomaNormanOK73019USA Ministry of Education Key Laboratory ofBiodiversity Science and Ecological Engineering Institute of Biodiversity ScienceFudan UniversityShanghai200433China KeyLaboratory of Land Surface Pattern and Simulation Institute of Geographic Sciences and Natural Resources ResearchChinese Academyof SciencesBeijing100101China

In the summer of 2012, the US Midwest, the most productive agricultural region in the world, experienced the most intense and widespread drought on record for the past hundred years. The 2012 drought, characterized as ‘flash drought’, developed in May with a rapid intensification afterwards, and peaked in mid-July. ~76% of crop region and 60% of grassland and pasture regions have been under moderate to severe dry conditions. This study used multiple lines of evidences, i.e., in-situ AmeriFlux measurements, spatial satellite observations, and scaled ecosystem modeling, to provide independent and complementary analysis on the impact of 2012 flash drought on the US Midwest vegetation greenness and photosynthesis carbon uptake. Three datasets consistently showed that 1) phenological activities of all biomes advanced 1–2 weeks earlier in 2012 compared to the other years of 2010–2014;2) the drought had a more severe impact on agroecosystems(crop and grassland) than on forests;3) the growth of crop and grassland was suppressed from June with significant reduction of vegetation index, sun-induced fluorescence(SIF) and gross primary production(GPP), and did not recover until the end of growing season. The modeling results showed that regional total GPP in 2012 was the lowest(1.76 Pg C/yr) during 2010–2014, and decreased by 63 Tg C compared with the other-year mean. Agroecosystems, accounting for 84% of regional GPP assimilation, were the most impacted by 2012 drought with total GPP reduction of 9%, 7%, 6%, and 29% for maize, soybean, cropland, and grassland, respectively. The frequency and severity of droughts have been predicted to increase in future. The results imply the importance to investigate the influences of flash droughts on vegetation productivity and terrestrial carbon cycling.

关键词： food security terrestrial carbon cycling eddy covariance Vegetation Photosynthesis Model sun-induced fluorescence(SIF)

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Optically levitated micro gyroscopes with an MHz rotational vaterite rotor

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Microsystems & Nanoengineering 2024年第3期10卷 219-227页

作者： Kai Zeng xiangming Xu Yulie Wu Xuezhong Wu Dingbang xiao College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China College of Information and Communication National University of Defense TechnologyWuhan 430000China Key Laboratory of Satellite Navigation Technology National University of Defense TechnologyChangsha 410073China

The field of levitated optomechanics has experienced significant advancements in manipulating the translational and rotational dynamics of optically levitated particles and exploring their sensing *** concept of using optically levitated particles as gyroscopes to measure angular motion has long been explored but has not yet been proven either theoretically or *** this study,we present the first rotor gyroscope based on optically levitated high-speed rotating *** gyroscope is composed of a micrometer-size ellipsoidal vaterite particle that is driven to rotate at MHz frequencies in a vacuum *** an external angular velocity is input,the optical axis deviates from its initial position,resulting in changes in the frequency and amplitude of the rotational *** analyzing these changes,the angular velocity of the input can be accurately detected,making it the smallest rotor gyroscope in the *** angular rate bias instability of the gyroscope is measured to be 0.08°/s and can be further improved to as low as 10^(−9)°/h theoretically by cooling the motion and increasing the angular moment of the levitated *** work opens a new application paradigm for levitated optomechanical systems and may pave the way for the development of quantum rotor gyroscopes.

关键词： particles rotational angular

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The relationships between urban-rural temperature difference and vegetation in eight cities of the Great Plains

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Frontiers of Earth Science 2019年第2期13卷 290-302页

作者： Yaoping CUI xiangming xiao Russell B DOUGHTY Yaochen QIN Sujie LIU Nan LI Guosong ZHAO Jinwei DONG Laboratory of Geospatial Technology for the Middle and Lower Yellow River Regions Henan UniversityKaifeng 475004China Department of Microbiology and Plant Biology Center for Spatial AnalysisUniversity of OklahomaNormanOK 73019USA Ministry of Education Key Laboratory of Biodiversity Science and Ecological Engineering Institute of Biodiversity ScienceFudan UniversityShanghai 200438China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

Interpreting the relationship between urban heat island (UHI) and urban vegetation is a basis for understanding the impacts of underlying surfaces on UHL The calculation of UHI intensity (UHII) requires observations from paired stations in both urban and rural *** to the limited number of paired meteorological stations,many studies have used remotely sensed land surface temperature,but these time-series land surface temperature data are often heavily affected by cloud cover and other *** factors,together with the algorithm for inversion of land surface temperature,lead to accuracy problems in detecting the UHII,especially in cities with weak *** on meteorological observations from the Oklahoma Mesonet,a world-class network,we quantified the UHII and trends in eight cities of the Great Plains,USA,where data from at least one pair of urban and rural meteorological stations were *** examined the changes and variability in urban temperature,UHII,vegetation condition (as measured by enhanced vegetation index,EVI),and evapotranspiration (ET).We found that both UHI and urban cold islands (UCI) occurred among the eight cities during 2000-2014 (as measured by impervious surface area).Unlike what is generally considered,UHII in only three cities significantly decreased as EVI and ET increased (p < 0.1),indicating that the UHI or UCI cannot be completely explained simply from the perspective of the underlying *** vegetative cover (signaled by EVI) can increase ET,and thereby effectively mitigate the *** study station clearly showed that the underlying surface or vegetation affects urban-rural temperature,and that these factors should be considered during analysis of the UHI effect over time.

关键词： urbanization evapotranspiration urban cold island background climate air temperature

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