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Journal of Geographical Sciences 2023年第5期33卷 924-944页

作者： MA Dujuan wu xiaodan WANG Jingping MU Cuicui College of Earth and Environmental Sciences Lanzhou UniversityLanzhou730000China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) ZhuhaiGuangdong611930China University Cooperation of Polar Research Beijing100875China

The trend estimate of vegetation change is essential to understand the change rule of the *** studies were mainly focused on quantifying trends or analyzing their spatial distribution ***,the uncertainties of trend estimates caused by spatiotemporal scale effects have rarely been *** response to this challenge,this study aims to investigate spatiotemporal scale effects on trend estimates using Moderate-Resolution Imaging Spectroradiometer(MODIS)Normalized Difference Vegetation Index(NDVI)and Gross Primary Productivity(GPP)products from 2001 to 2019 in the Qinghai-Tibet Plateau(QTP).Moreover,the possible influencing factors on spatiotemporal scale effect,including spatial heterogeneity,topography,and vegetation types,were *** results indicate that the spatial scale effect depends more on the dataset with a coarser spatial resolution,and temporal scale effects depend on the time span of ***,the trend estimates on the 8-day and yearly scale are much closer than that on the monthly *** addition,in areas with low spatial heterogeneity,low topography variability,and sparse vegetation,the spatiotemporal scale effect can be ignored,and vice *** results in this study help deepen the consciousness and understanding of spatiotemporal scale effects on trend detection.

关键词： spatiotemporal scale effect satellite dataset trend estimates NDVI influencing factors GPP

Geochemical processes controlling dissolved selenium in the Changjiang(Yangtze) Estuary and its adjacent waters

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Acta Oceanologica Sinica 2014年第10期33卷 19-29页

作者： wu xiaodan SONG Jinming wu Bin LI Tiegang LI Xuegang Institute of Oceanology Chinese Academy of Sciences University of Chinese Academy of Sciences

Dissolved selenium in the Changjiang（Yangtze） Estuary and its adjacent waters was determined by hydride generation atomic fluorescence spectrometry to elucidate the source, behavior in estuary, adsorption-desorption process and biological role. In surface water, Se（IV） concentration ranged 0.05–1.14 nmol/L and Se（VI） concentration varied 0.01–1.20 nmol/L, with the means of 0.76 and 0.49 nmol/L, respectively. In bottom water, Se（IV） content varied 0.03–0.27 nmol/L and Se（VI） content ranged 0.04–0.85 nmol/L, with the averages of 0.10 and 0.40 nmol/L, respectively. High level of Se（IV） was observed near the shore with a significant decrease towards the open sea, suggesting the continental input from the adjacent rivers. Large value of Se（VI） was found in bottom water, reflecting the release from suspended sediment. Besides, high value appeared in the same latitude of the Changjiang Estuary and Hangzhou Bay illustrated the effect of lateral mixing and the long-distance transport of selenium. Se（VI）, more soluble, occupied higher percentage in aqueous environment. The presence of Se（IV） resulted from the degradation of residue and the reduction of Se（VI） under anaerobic condition. The positive relationship to suspended particulate material（SPM） and negative correlation to depth indicated that Se（IV） tended to be released from the high density particulate matter. Instead, Se（VI） content did not significantly relate to SPM since it generally formed inner-sphere complex to iron hydroxide. Se（IV） content negatively varied to salinity and largely depended on the freshwater dilution and physical mixing. While, Se（VI） level deviated from the dilution line due to the in situ biogeochemical process such as removal via phytoplankton uptake and inputs via organic matter regeneration. As the essential element, Se（IV） was confirmed more bioavailable to phytoplankton growth than Se（VI）, and moreover, seemed to be more related to phosphorus than to nitrogen.

关键词： dissolved selenium distribution geochemical behavior Changjiang(Yangtze) Estuary

Transformation of hydroxylated and methoxylated 2,2′,4,4′,5-brominated diphenyl ether(BDE-99) in plants

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Journal of Environmental Sciences 2016年第11期28卷 197-202页

作者： Lili Pan Jianteng Sun xiaodan wu Zi Wei Lizhong Zhu Department of Environmental Science Zhejiang University Hangzhou 310058 China. Zhejiang Provincial Key Laboratory of Organic Pollution Process and Control Hangzhou 310058 China Analysis and Measurement Center Zhejiang University Hangzhou 310058 China

The occurrence and fate of hydroxylated polybrominated diphenyl ethers（OH-PBDEs） and methoxylated polybrominated diphenyl ethers（Me O-PBDEs） have received significant attention. However, there is limited information on the metabolism relationship between OH-pentaB DEs and MeO-pentaB DEs that were frequently detected with relatively high concentrations in the environment. In this study, the biotransformation between OH-BDE-99 and MeO-BDE-99 was investigated in rice, wheat, and soybean plants. All the three plants can metabolize OH-BDE-99 to corresponding homologous methoxylated metabolites, while the transformation from MeO-BDE-99 to OH-BDE-99 could only be found in soybean. The conversion of parent compounds was the highest in soybean, followed by wheat and rice. Transformation products were found mainly in the roots, with few metabolites being translocated to the shoots and solution after exposure. The results of this study provide valuable information for a better understanding of the accumulation and transformation of OH-PBDEs and MeO-PBDEs in different plants.

关键词： OH-PBDEs MeO-PBDEs Biotransformation Plant

Effects of Processing Parameters on Microstructure and Properties of Ultra High Strength Linepipe Steel

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Journal of Materials Science & Technology 2012年第10期28卷 889-894页

作者： xiaodan wu Hakcheol Lee Young Min Kim Nack J.Kim University of Pittsburgh Pittsburghl PA 15213USA Pohang University of Science and Technology Pohang 790-784Korea

To examine the effect of processing parameters on microstructural evolution and to obtain the excellent combination of strength and toughness, simulation of thermo-mechanical processing was conducted using the Gleeble machine. Trial production was then conducted under the conditions obtained by Gleeble tests. Based on the results of microstructure analysis and mechanical property evaluation, the relationship between microstructural features and mechanical properties was elucidated. The result shows that the volume fraction of constituted phases can be controlled through adjusting the cooling rate and finish cooling temperature in order to get different strength levels. As cooling rate increases, the volume fraction of upper bainite increases, which leads to the increase of strength. The upper shelf energy （USE） increases with increasing volume fraction of acicular ferrite in bainite base because of the small effective acicular ferrite grain size. Ductile-brittle transition temperature （DBTT） decreases with increasing acicular ferrite volume fraction. High reduction in the rough stage has great influence on grain refinement.

关键词： Linepipe steel Microstructure Gleeble test TMCP (thermomechanicalcontrol process)

Response Time of Reactive Power Based on Different Definitions and Algorithms

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Journal of Modern Power Systems and Clean Energy 2021年第2期9卷 440-449页

作者： Taixun Fang Qiwen Zhou Fengfeng Ding xiaodan wu Zhao Li Houjun Tang NR Electric Co. Ltd.NanjingChina the Key Laboratory of Control of Power Transmission and Transformation Ministry of EducationShanghai Jiao Tong UniversityShanghaiChina

Dynamic reactive power compensation equipment typically requires a fast response to output the necessary reactive *** term"dynamic response time of reactive power"is often used but has never been clearly *** paper summarizes the reactive power calculations under different definitions and algorithms and considers these calculations in terms of signal processing to simulate and analyze the step *** paper subsequently focuses on the widely used instantaneous reactive power algorithm and finally concludes that the dynamic reactive power response time closely depends on the reactive power calculation method *** single-phase instantaneous reactive power algorithm has the fastest response *** reactive power response time of dynamic reactive devices in power systems is a minimum of a quarter of one cycle time for the well-known and widely used single-phase reactive power algorithms.

关键词： Response time reactive power instantaneous reactive power Hilbert transform phase shift synchronous reference frame

Optimization Study of Active-Passive Heating System Parameters in Village Houses in the Southern Xinjiang Province

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Energy Engineering 2024年第7期121卷 1963-1990页

作者： xiaodan wu Jie Li Yongbin Cai Sihui Huang College of Water Conservancy&Architectural Engineering Shihezi UniversityShihezi823000China Scientific Research Department Shihezi UniversityShihezi823000China

Aiming at the problems of large energy consumption and serious pollution of winter heating existing in the rural buildings in Southern Xinjiang,a combined active-passive heating system was proposed,and the simulation software was used to optimize the parameters of the system,according to the parameters obtained from the optimization,a test platform was built and winter heating test was carried *** simulation results showed that the thickness of the air layer of 75 mm,the total area of the vent holes of 0.24 m^(2),and the thickness of the insulation layer of 120 mm were the optimal construction for the passive part;solar collector area of 28 m^(2),hot water storage tank volume of 1.4 m^(3),mass flow rate of 800 kg/h on the collector side,mass flow rate of 400 kg/h on the heat exchanger side,and output power of auxiliary heat source of 5∼9 kWwere the optimal constructions for active heating *** results showed that during the heating period,the system could provide sufficient heat to the room under different heating modes,and the indoor temperature reached over 18°C,which met the heating *** economic and environmental benefits of the system were analyzed,and the economic benefits of the systemwere better than coal-fired heating,and the CO_(2) emissionswere reduced by 3,292.25 kg compared with *** results of the study showed that the combinedactive-passiveheating systemcouldeffectively solve the heating problems existing in rural buildings in Southern Xinjiang,and it also laid the theoretical foundation for the popularization of the combined heating systems.

关键词： Trombe wall biomass boilers active-passive combined heating systems parameter optimization villages and towns

Distribution, sources and burial fl ux of sedimentary organic matter in the East China Sea

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Journal of Oceanology and Limnology 2020年第5期38卷 1488-1501页

作者： wu xiaodan wu Bin JIANG Mingyu CHANG Fengming NAN Qingyun YU Xinke Saren Gaowa CAS Key Laboratory of Marine Geology and Environment Institute of OceanologyChinese Academy of SciencesQingdao 266071China Key Laboratory of Marine Geology and Metallogeny First Institute of OceanographyMinistry of Natural ResourcesQingdao 266061China Laboratory for Marine Geology Qingdao National Laboratory for Marine Science and TechnologyQingdao 266237China Center for Ocean Mega-Science Chinese Academy of SciencesQingdao 266071China

Distribution of total organic carbon(TOC),total nitrogen(TN),stable isotope ratio of organic carbon and nitrogen(δ13 C andδ15 N)in 31 surface sediments were examined to quantitatively discriminate the source and burial of sedimentary organic matter(SOM)in the East China Sea(ECS).Results show that high content of TOC and TN occurred in the southern inner shelf and the northeast area due to the transport of organic matter(OM)from the Changjiang(Yangtze)River southwards by the Zhejiang Fujian Coastal Current(ZFCC)and the delivery from the old Huanghe(Yellow)River estuary by the Subei Coastal Current(SbCC),*** signifi cant relationship of TOC to clay provided evidence that the fi ne-grained sediment was the primary carrier for SOM from the inner shelf to open *** TN varied proportionally to the TOC with the neglected intercept,suggesting that most of nitrogen measured was related to the SOM and the infl uence of the sorption of inorganic nitrogen was insignifi *** seaward enrichment ofδ13 C and seaward depletion of C/N andδ15 N illustrated the decrease of terrestrial OM(TOM)and the increase of marine OM(MOM).The close of average C/N ratio to the Redfi eld ratio indicated the minor role of terrestrial plant debris in the *** of bulk OM properties was ascribed to the terrestrial and marine input by the shelf circulation and phytoplankton with the contributions of 76.1%MOM and 23.9%TOM to SOM,*** burial fl ux of OC ranged within 0.34–7.56 mg/(cm 2∙a)(averaged 2.80 mg/(cm 2∙a))and enriched along the shore and in the fi ne-grained area,manifesting the signifi cant input of the land-based sources and the eff ect of shelf mud depositional process on the fate of *** sharp seaward decrease of burial fl uxes of terrestrial and marine OC gave evidences that the majority of organic carbon were settled in the inner shelf with the small fraction of them further transported eastwards.

关键词： distribution sedimentary organic matter sources burial East China Sea(ECS)

Plant N-acylethanolamines play a crucial role in defense and its variation in response to elevated CO_(2) and temperature in tomato

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Horticulture Research 2023年第1期10卷 207-219页

作者： Zhangjian Hu Junying Shi Shuxian Feng xiaodan wu Shujun Shao Kai Shi Hainan Institute Zhejiang UniversityYazhou Bay Science and Technology CitySanya 572025China Department of Horticulture Zhejiang University310058China Analysis Center of Agrobiology and Environmental Science Zhejiang UniversityHangzhou310058China

The ubiquitous lipid-derived molecules N-acylethanolamines(NAEs)have multiple immune functions in mammals,but their roles and mechanisms in plant defense response during changing environment remain largely ***,we found that exogenous NAE18:0 and NAE18:2 promoted defense against the necrotrophic pathogen Botrytis cinerea but suppressed defense to the hemi-biotrophic pathogen Pseudomonas syringae ***(Pst)DC3000 in *** knocking-down and overexpression function analysis of the pathogen-responsive NAE synthetic gene PHOSPHOLIPASE Dγ(PLDγ)and hydrolytic gene FATTY ACID AMID HYDROLASE 1(FAAH1)revealed that the NAE pathway is crucial for plant defense *** exogenous applications and SA-abolished NahG plants,we unveiled the antagonistic relationship between NAE and SA in plant defense *** CO_(2) and temperature significantly changed the NAE pathway in response to pathogens,while inhibition of the NAE pathway led to the alternation of environment-mediated defense variations against Pst DC3000 in tomato,indicating that NAE pathway is associated with plant defense variations in response to elevated CO_(2) and *** results herein reveal a new function of NAE in plant defense,and its involvement in environment-mediated defense variation in *** findings shed light on the NAE-based plant defense,which may have relevance to crop disease management in future changing climate.

关键词： elevated defense Plant

Forward a spatio-temporal trend surface for long-term groundmeasured albedo upscaling over heterogeneous land surface

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International Journal of Digital Earth 2018年第5期11卷 470-484页

作者： xiaodan wu Jianguang Wen Qing Xiao Dongqin You Qiang Liu Xingwen Lin State Key Laboratory of Remote Sensing Science Institute of Remote Sensing and Digital EarthChinese Academy of SciencesBeijingPeople’s Republic of China College of Resources and Environment University of Chinese Academy of SciencesBeijingPeople’s Republic of China Joint Center for Global Change Studies BeijingPeople’s Republic of China College of Global Change and Earth System Science Beijing Normal UniversityBeijingPeople’s Republic of China

Upscaling ground albedo is challenged by the serious discrepancy between the heterogeneity of land surfaces and the small number of ground-based *** ground-based measurements cannot provide sufficient information on the characteristics of surface albedo at the scale of coarse pixels over heterogeneous land *** method of overcoming this problem is to introduce high-resolution albedo imagery as ancillary information for ***,due to the low frequency of updating of high-resolution albedo maps,upscaling time series of ground-based albedo measurements is *** paper proposes a method that is based on the idea of conceptual universal scaling methodology for establishing a spatiotemporal trend surface using very few high-resolution images and time series of ground-based measurements for spatial-temporal upscaling of *** construction of the spatiotemporal trend surface incorporates the spatial information provided by auxiliary remote sensing images and the temporal information provided by long time series of ground *** approach was illustrated by upscaling ground-based fine-scale albedo measurements to a coarse scale over the core study area in *** results indicate that this method can characterize the spatiotemporal variations in surface albedo well,and the overall correlation coefficient was 0.702 during the study period.

关键词： Trend surface upscaling spatiotemporal heterogeneous albedo

Evaluation of several recently developed sampling strategies within the coarse pixel scale for validation of coarse-resolution satellite albedo products

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International Journal of Digital Earth 2022年第1期15卷 2319-2334页

作者： Rongqi Tang xiaodan wu Jingping Wang Qicheng Zeng Zheng Li Jianguang Wen College of Earth and Environmental Sciences Lanzhou UniversityLanzhouPeople’s Republic of China State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of SciencesBeijingPeople’s Republic of China University of Chinese Academy of Sciences BeijingPeople’s Republic of China

Due to the spatial heterogeneity and the spatial scale mismatch between in situ and satellite-based measurements,optimal ground sampling should be made to increase the representativeness of in situ observations. Therefore,many ground sampling strategies have been proposed,but their performance within the coarse pixel has not been evaluated. Hence,this study evaluated four typical methods regarding their ability to obtain pixel scale ground ‘truth’. Random combination (RC) performs best,with the always fewest samples to satisfy representativeness errors (REs) of 3% in the case of a small number of samples. When the goal of sampling is to obtain in situ measurements with REs close to 0 at the expense of increasing the number of samples,cumulative representativeness sampling (CRS) is more effective than RC in less heterogeneous areas. Geo-statistical model-based sampling (GSS) does not work well because the number of samples within the coarse pixel scale cannot support a robust semi-variogram model. Stratified sampling (SS) is highly dependent on spatial heterogeneity and does not work well in the case of small sample sizes. This study gives important guidance for ground sample deployment within the coarse pixel for validation of coarse-resolution satellite albedo products over a heterogeneous surface.

关键词： Sampling spatial heterogeneity validation representative observations coarse-pixel scale