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A FRAMEWORK FOR AUTOMATED CHANGE DETECTION SYSTEM

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Geo-Spatial Information Science 2001年第3期4卷 29-34页

作者： SUI haigang li Deren liESMARS Wuhan University

To enhance the ability of remote sensing system to provide accurate,timely,and complete geo_spatial information at regional or global scale,an automated change detection system has been and will continue to be one of the important and challenging problems in remote *** this paper,the authors propose a framework for automated change detection system at landscape level using various geo_spatial data sources including multi_sensor remotely sensed imagery and ancillary data *** this framework,database is the central part and some associated techniques are *** techniques includes five subsystems:automated feature_based image registration,automated change finding,automated change feature extraction and identification,intelligent change recognition,change accuracy assessment and database updating and visualization.

关键词： change detection difference image change vector

Estimates for stress concentration between two adjacent rigid inclusions in two-dimensional Stokes flow

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Science China Mathematics 2024年

作者： haigang li Longjuan Xu School of Mathematical Sciences Beijing Normal University Academy for Multidisciplinary Studies Capital Normal University

It is vitally important in material sciences and fluid mechanics to study the field enhancements in the narrow region between two inclusions. Complex fluids including particle suspensions usually result in complicated flow behavior. In this paper, we establish the pointwise upper bounds of the gradient and the second-order partial derivatives for the Stokes flow when two rigid particles are closely spaced, suspending in an open bounded domain and away from the boundary in dimension two. Moreover, the lower bounds of the gradient estimates at the narrowest place of the neck region show the optimality of the blow-up rate. These results are valid for inclusions with arbitrary shapes.

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Combining field data and modeling to better understand maize growth response to phosphorus(P) fertilizer application and soil P dynamics in calcareous soils

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Journal of Integrative Agriculture 2024年第3期23卷 1006-1021页

作者： Weina Zhang Zhigan Zhao Di He Junhe liu haigang li Enli Wang School of Biological and Food Processing Engineering Huanghuai UniversityZhumadian 463000China Key Laboratory of Plant-Soil Interactions Ministry of Education/College of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resources/Key Laboratory of Grassland Resource(IMAU) Ministry of Education/College of GrasslandResources and EnvironmentInner Mongolia Agricultural UniversityHohhot 010018China CSIRO Agriculture and Food CanberraACT 2601Australia

We used field experimental data to evaluate the ability of the agricultural production system model (APSIM) to simulate soil P availability,maize biomass and grain yield in response to P fertilizer applications on a fluvo-aquic soil in the North China *** and soil data from a 2-year experiment with three P fertilizer application rates(0,75 and 300 kg P_(2)O_(5) ha^(–1)) were used to calibrate the *** analysis was carried out to investigate the influence of APSIM SoilP parameters on the simulated P availability in soil and maize *** and soil P parameters were then derived by matching or relating the simulation results to observed crop biomass,yield,P uptake and Olsen-P in *** re-parameterized model was further validated against 2 years of independent data at the same *** re-parameterized model enabled good simulation of the maize leaf area index (LAI),biomass,grain yield,P uptake,and grain P content in response to different levels of P additions against both the calibration and validation *** results showed that APSIM needs to be re-parameterized for simulation of maize LAI dynamics through modification of leaf size curve and a reduction in the rate of leaf senescence for modern staygreen maize cultivars in *** P concentration limits (maximum and minimum P concentrations in organs)at different stages also need to be *** results further showed a curvilinear relationship between the measured Olsen-P concentration and simulated labile P content,which could facilitate the initialization of APSIM P pools in the NCP with Olsen-P measurements in future *** remains difficult to parameterize the APSIM SoilP module due to the conceptual nature of the pools and simplified conceptualization of key P transformation processes.A fundamental understanding still needs to be developed for modelling and predicting the fate of applied P fertilizers in soils with contrasting physical and chemical characteristics.

关键词： maize phosphorus availability modeling APSIM maize APSIM SoilP

Contrasting patterns of accumulation,partitioning,and remobilization of biomass and phosphorus in a maize cultivar

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The Crop Journal 2022年第1期10卷 254-261页

作者： Weina Zhang haigang li Junling Zhang Jianbo Shen Hamish Brown Enli Wang Key Laboratory of Plant-Soil Interactions Ministry of EducationCollege of Resources and Environmental SciencesChina Agricultural UniversityBeijing 100193China School of Biological and Food Processing Engineering Huanghuai UniversityZhumadian 463000HenanChina Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resources Key Laboratory of Grassland Resource(IMAU)Ministry of EducationCollege of GrasslandResources and EnvironmentInner Mongolia Agricultural UniversityHohhot 010018Inner MongoliaChina The New Zealand Institute for Plant&Food Research limited Private Bag 4704ChristchurchNew Zealand CSIRO Agriculture and Food GPO Box 1700CanberraACT 2601Australia

Maize growth,organ development,and yield formation are highly controlled by the manner in which the plant captures,partition,and remobilizes biomass and phosphorus(P).Better understanding of biomass and P accumulation,partition,and remobilization processes will improve modeling of crop resource ***,there is still a lack of detailed data to parameterize the modeling of these processes,particula rly for modern maize cultivars.A two-year(2016 and 2017)field experiment with three P fertilization treatments(0(P0),75(P75),and 300(P300)kg P_(2)O_(5)ha^(-1))was conducted on a Fluvo-aquic soil(Quzhou,Hebei province,China)to collect data and quantify key processes for a representative modern maize cultivar(Zhengdan 958)widely grown in *** proportions of biomass and P partitioned into various maize organs were unaffected by P application *** 958 showed a much lower leaf-senescence rate than older cultivars,resulting in post-silking leaf photosynthesis being sufficient to meet grain biomass *** contrast,50%-85%of leaf P and 15%-50%of stem P accumulated pre-silking were remobilized into grain,in spite of the large proportion of post-silking P *** results are consistent with the theory that plants use resources according to the priority order of re-allocation from senescence followed by assimilation and uptake,with the re-translocation of reserves *** results also enabled us to estimate the threshold P concentrations of Zhengdan 958 for modeling crop P *** critical leaf P concentration for individual leaves was 0.25%-0.30%,with a corresponding specific leaf P(SLP)of 75-100 mg P m^(-2).The structural P concentration for leaf was 0.01%,corresponding to an SLP of 3.8 mg P m^(-2).The maximum P concentrations of leaves and stems were 0.33%and 0.29%.The residual P concentration for stems was 0.006%.

关键词： Biomass Phosphorus Partitioning Remobilization Individual leaves

Asymptotic estimates for slowly rotating Newtonian stars

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Frontiers of Mathematics in China 2012年第6期7卷 1141-1149页

作者： haigang li Jiguang BAO School of Mathematical Sciences Beijing Normal University Laboratory of Mathematics andComplex Systems Ministry of Education Beijing 100875 China

This work is mainly concerned with the rotating Newtonian stars with prescribed angular velocity law existence of rotating star solutions For general compressible fluids, the was proved by using concentration- compactness principle. In this paper, we establish the asymptotic estimates on the diameters of the stars with small rotation. The novelty of this paper is that a direct and concise definition of slowly rotating stars is given, different from the case with given angular momentum law, and the most general fluids are considered.

关键词： Slowly rotating star asymptotic estimate axi-symmetry

Comparison of analytical procedures for measuring phosphorus content of animal manures in China

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Frontiers of Agricultural Science and Engineering 2019年第4期6卷 431-440页

作者： Guohua li Qian liU haigang li Fusuo ZHANG Center for Resources Environment and Food Security(CREFS)China Agricultural UniversityBeijing 100193China Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resources Key Laboratory of Grassland ResourcesMinistry of EducationCollege of GrasslandResources and EnvironmentInner Mongolia Agricultural UniversityHohhot 010018China

The concentration and components of manure phosphorus(P)are key factors determining potential P bioavailability and *** distribution of P forms in swine,poultry and cattle manures collected from intensive and extensive production systems in several areas of China was investigated with sequential fractionation and a simplified two-step(NaHCO3-NaOH/EDTA)*** mean total P concentration,determined by the sequential fractionation procedure of intensive swine,poultry and cattle manure,expressed as g·kg–1,was 14.9,13.4 and 5.8 g·kg–1,respectively,and 4.4 g·kg–1 in extensive cattle *** intensive swine,poultry and cattle manure about 73%,74%and 79%of total P,respectively,was bioavailable(i.e.,P extracted by H2O and NaHCO3)and 78%in extensive cattle *** results indicated the relative environmental risk,from high to low,of swine,poultry and cattle *** is considerable regional variation in animal manure P across China,which needs to be considered when developing manure management strategies.

关键词： diet phosphorus manure phosphorus sequential P fractionation

Combined Applications of Nitrogen and Phosphorus Fertilizers with Manure Increase Maize Yield and Nutrient Uptake via Stimulating Root Growth in a Long-Term Experiment

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Pedosphere 2016年第1期26卷 62-73页

作者： WEN Zhihui SHEN Jianbo Martin BLACKWELL li haigang ZHAO Bingqiang YUAN Huimin College of Resources and Environmental Sciences China Agricultural University Rothamsted Research North Wyke Institute of Agricultural Resources and Regional Planning China Academy of Agricultural Sciences

Imbalanced application of nitrogen(N) and phosphorus(P) fertilizers can result in reduced crop yield,low nutrient use efficiency,and high loss of nutrients and soil nitrate nitrogen(NO_3^--N) accumulation decreases when N is applied with P and/or manure;however,the effect of applications of N with P and/or manure on root growth and distribution in the soil profile is not fully *** aim of this study was to investigate the combined effects of different N and P fertilizer application rates with or without manure on maize(Zea mays L.) yield,N uptake,root growth,apparent N surplus,Olsen-P concentration,and mineral N(N_(min)) accumulation in a fluvo-aquic calcareous soil from a long-term(28-year) *** experiment comprised twelve combinations of chemical N and P fertilizers,either with or without chicken manure,as treatments in four *** yield of maize grain was 82%higher,the N uptake 100%higher,and the N_(min) accumulation 39%lower in the treatments with combined N and P in comparison to N fertilizer *** maize root length density in the 30-60 cm layer was three times greater in the treatments with N and P fertilizers than with N fertilizer *** addition increased maize yield by 50%and N uptake by 43%,and reduced N_(min)(mostly NO_3^--N) accumulation in the soil by 46%.The long-term application of manure and P fertilizer resulted in significant increases in soil Olsen-P concentration when no N fertilizer was *** application reduced the apparent N surplus for all *** results suggest that combined N and P fertilizer applications could enhance maize grain yield and nutrient uptake via stimulating root growth,leading to reduced accumulation of potentially leachable NO_3^--N in soil,and manure application was a practical way to improve degraded soils in China and the rest of the world.

关键词： apparent N surplus degraded soils chemical fertilizers nitrate nitrogen root length density soil mineral N soil Olson-P

A conceptual framework and an empirical test of complementarity and facilitation with respect to phosphorus uptake by plant species mixtures

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Pedosphere 2022年第2期32卷 317-329页

作者： Chunjie li Thomas W.KUYPER Wopke VAN DER WERF Junling ZHANG haigang li Fusuo ZHANG Ellis HOFFLAND College of Resources and Environmental Science National Academy of Agriculture Green DevelopmentChina Agricultural UniversityBeijing 100193China Wageningen University Soil Biology GroupP.O.Box 476700 AA WageningenThe Netherlands Wageningen University Centre for Crop Systems AnalysisP.O.Box 4306700 AK WageningenThe Netherlands Inner Mongolia Key Laboratory of Soil Quality and Nutrient Resources Key Laboratory of Grassland Resource(IMAU)Ministry of EducationCollege of GrasslandResources and EnvironmentInner Mongolia Agricultural UniversityHohhot 010018China

Plant species have different traits for mobilizing sparingly soluble phosphorus (P) resources,which could potentially lead to overyielding in P uptake by plant species mixtures compared to monocultures due to higher P uptake as a result of resource (P) partitioning and ***,there is circumstantial evidence at best for overyielding as a result of these *** (the outcome) is easily confused with underlying mechanisms because of unclear *** aimed to define a conceptual framework to separate outcome from underlying mechanisms and test it for facilitation and complementarity with respect to P acquisition by three plant species combinations grown on four *** conceptual framework describes both mechanisms of complementarity and facilitation and outcomes (overyielding of mixtures or no overyielding) depending on the competitive ability of the species to uptake the mobilized ***/chickpea mixtures were grown in pots on two calcareous soils mixed with calcium-bound P (CaP) and phytate P (PhyP).Cabbage/faba bean mixtures were grown on both acid and neutral soils mixed with P-coated iron (hydr)oxide (FeP) and ***/maize mixtures were grown on all four *** carboxylate concentration and acid phosphatase activity (mechanisms) as well as plant P uptake and biomass (outcome) were determined for monocultures rhizosphere and species *** of P uptake occurred in millet/chickpea mixtures on one calcareous *** found no indications for P acquisition from different P sources,neither in millet/chickpea,nor in cabbage/faba bean *** and faba bean on the neutral soil differed in rhizosphere acid phosphatase activity and carboxylate concentration,but showed no *** and maize,with similar root exudates,showed overyielding (the observed P uptake being 22%higher than the expected P uptake) on one calcareous *** concluded that although differences in plant physiological tr

关键词： carboxylate intercrop phosphatase phosphorus acquisition phosphorus mobilization phoshorus source rhizosphere root exudation

Analysis and Representation of Changes in Change Detection

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Geo-Spatial Information Science 2002年第2期5卷 13-16页

作者： SUI haigang li Deren GONG Jianya ZHU Qing liESMARS Wuhan University

In this paper,factors lead to changes and what changes should be considered are firstly *** changes to be represented by set theory is *** basic change types are described in *** last the paper points out that the change between geo_objects and pixels in images is not all corresponding and it causes the difficulty of accurate and robust change detection techniques.

关键词： change detection analysis of changes representation of changes