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Simulating Alpine Vegetation Net Primary Productivity by Remote Sensing in Qinghai Province,China

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Journal of Mountain Science 2014年第4期11卷 967-978页

作者： WEI Ya-xing WANG Li-wen Center for Marine Economic and sustainable development Liaoning Normal University Liaoning Key Laboratory of Physical geography and Geomatics Liaoning Normal University College of Urban and Environmental Science Liaoning Normal University

Primary productivity of ecosystem is important indicator about ecological assessment. Remote sensing technology has been used to monitor net primary productivity （NPP） of ecological system for several years. In this paper, the remotely sensed NPP simulation model of alpine vegetation in Qinghai Province of Tibet Plateau was set up based on the theory of light use efficiency. Firstly a new approach based on mixed pixels and Support Vector Machine （SVM） algorithm were used to correct simulated NPP values derived from Moderate Resolution Imaging Spectroradiometer （MODIS） data. Finally, spatial distribution and monthly variation characteristics of NPP in Qinghai Province detail. The result showed in 2006 were analyzed in that NPP of vegetation in Qinghai Province in 2006 ranged from o to 422 gC/m2/a and the average NPP was 151 gC/m2/a. NPP gradually increased from northwest to southeast. NPP of different vegetation types were obviously different. The average NPP of broad-leaved forest was the largest （314 gC/m2/a）, and sparse shrub was the smallest （101 gC/m2/a）. NPP in Qinghai Province significantly changed with seasonal variation. The accumulation of NPP was primarily in the period （from April to September） with better moist and heat conditions. In July, the average NPP of vegetation reached the maximum value （43 gC/m2）. In our model, the advantage of traditional LUE models was adopted, and our study fully considered typicalcharacteristics of alpine vegetation light use efficiency and environmental factors in the study area. Alpine vegetation is the most important ecological resource of Tibet Plateau, exactly monitoring its NPP value by remote sensing is an effective protection measure.

关键词： Net primary productivity Remotesensing Light use efficiency model Contexturalapproach Support Vector Machine

Review of precipitation strengthening in ultrahigh-strength martensitic steel

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 256-269页

作者： Zhihao Tian Chunlei Shang Chaolei Zhang Xiaoye Zhou Honghui Wu Shuize Wang Guilin Wu Junheng Gao Jiaming Zhu Xinping Mao Institute for Carbon Neutrality University of Science and Technology BeijingBeijing 100083China Institute of Steel sustainable Technology Liaoning Academy of MaterialsShenyang 110004China Department of Materials Science and Engineering Shenzhen MSU-BIT UniversityShenzhen 518172China Institute of Materials Intelligent Technology Liaoning Academy of MaterialsShenyang 110004China school of Civil Engineering Shandong UniversityJinan 250061China

Martensite is an important microstructure in ultrahigh-strength steels,and enhancing the strength of martensitic steels often involves the introduction of precipitated phases within the martensitic *** considerable research efforts devoted to this area,a systematic summary of these advancements is *** review focuses on the precipitates prevalent in ultrahigh-strength martensitic steel,primarily carbides(e.g.,MC,M_(2)C,and M_(3)C)and intermetallic compounds(e.g.,Ni Al,Ni_(3)X,and Fe_(2)Mo).The precipitation-strengthening effect of these precipitates on ultrahigh-strength martensitic steel is discussed from the aspects of heat treatment processes,microstructure of precipitate-strengthened martensite matrix,and mechanical ***,a perspective on the development of precipitation-strengthened martensitic steel is presented to contribute to the advancement of ultrahigh-strength martensitic *** review highlights significant findings,ongoing challenges,and opportunities in the development of ultrahigh-strength martensitic steel.

关键词： ultrahigh-strength martensitic steel precipitation strengthening mechanical property carbide intermetallic compound

Examining the Spatiotemporal Dynamics and Determinants of Land Urbanization in Prefecture-level Cities,China

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Chinese Geographical Science 2024年第1期34卷 19-33页

作者： YANG Zhen ZHU Huxiao ZHANG Xinlin OU Xiangjun school of geography Geomatics and Planning&Urban-rural Integration Development Research InstituteJiangsu Normal UniversityXuzhou221116China

Examining the spatiotemporal dynamics and determinants of land urbanization is critical for promoting healthy urban development and the rational use of land *** on the dataset consisting of land use change data and selected factors in 2010 and2020,this study used visual analysis to reveal the spatiotemporal dynamics of land urbanization across prefecture-level cities in ***,the driving forces underlying land urbanization were examined by using geographical detector *** are the findings:1)we find that there exist notable spatial variances in land urbanization across prefecture-level ***,the differentiation in land urbanization between the northern and southern cities is more pronounced than that between the coastal and inland cities,or between the eastern and western ***-level cities located in central and western China have experienced the most rapid growth in land ***,the growth rate in northeastern China is the lowest,while the velocity in eastern China remains relatively *** using spatial autocorrelation analysis,this study reveals that the land urbanization level in prefecture-level cities has significant spatial agglomeration.2)We further find that land urbanization in China is influenced by factors related to urban land supply and demand,and urban population growth,economic growth,land financial and political incentive have greater impact on land urbanization than other factors.3)We also find that the impacts of determinants on China’s land urbanization vary over time,the explanatory power of economic development increased,while the explanatory power of state forces *** argue that integrating the supply and demand factors of land urbanization can provide a more comprehensive understanding of the driving mechanisms underlying land urbanization in China and other transitional countries,and help decision-makers in these countries formulate more detailed and specif

关键词： land urbanization spatial pattern influencing factor geographical detector China

Soil polygon disaggregation through similarity-based prediction with legacy pedons

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Journal of Arid Land 2016年第5期8卷 760-772页

作者： LIU Feng GENG Xiaoyuan ZHU A-xing Walter FRASER SONG Xiaodong ZHANG Ganlin State Key Laboratory of Soil and sustainable Agriculture Institute of Soil ScienceChinese Academy of Sciences Science and Technology Branch Agriculture and Agri-Food Canada school of geography Nanjing Normal University Department of geography University of Wisconsin-Madison

Conventional soil maps generally contain one or more soil types within a single soil *** their geographic locations within the polygon are not *** restricts current applications of the maps in site-specific agricultural management and environmental *** examined the utility of legacy pedon data for disaggregating soil polygons and the effectiveness of similarity-based prediction for making use of the under-or over-sampled legacy pedon data for the *** method consisted of three ***,environmental similarities between the pedon sites and each location were computed based on soil formative environmental ***,according to soil types of the pedon sites,the similarities were aggregated to derive similarity distribution for each soil ***,a hardening process was performed on the maps to allocate candidate soil types within the *** study was conducted at the soil subgroup level in a semi-arid area situated in Manitoba,*** on 186 independent pedon sites,the evaluation of the disaggregated map of soil subgroups showed an overall accuracy of 67% and a Kappa statistic of *** map represented a better spatial pattern of soil subgroups in both detail and accuracy compared to a dominant soil subgroup map,which was commonly used in *** predictions mainly occurred in the agricultural plain area and the soil subgroups that are very similar in taxonomy,indicating that new environmental covariates need to be *** concluded that the combination of legacy pedon data with similarity-based prediction is an effective solution for soil polygon disaggregation.

关键词： legacy pedon data similarity-based prediction spatial disaggregation conventional soil maps

A strategy of the rural governance for territorial spatial planning in China

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Journal of Geographical Sciences 2021年第9期31卷 1349-1364页

作者： GE Dazhuan LU Yuqi Jiangsu Center for Collaborative Innovation in Geographical Information Resource development and Application School of GeographyNanjing Normal UniversityNanjing 210023China

Rural spatial governance has become an important part of the spatial governance system under the unified management of urban and rural ***-depth theoretical and practical research on rural spatial governance in terms of promoting national spatial planning can help improve the planning and regulation system of rural *** with a description of rural spatial governance,this paper constructs a theoretical analysis framework of rural spatial governance based on the comprehensive perspective of spatial *** study also discusses the internal processes and feasible paths of rural spatial governance in territorial spatial planning and outlines the theoretical and practical research for enhancing rural spatial *** conclusions are as follows:(1)Rural spatial governance starts with the coordination theory of human-land relationships in the rural regional *** planning and negotiation,governance has effective regulation of rural space and allocates spatial rights in an orderly *** spatial governance highlights the comprehensive governance processes that combine"top-down"and"bottom-up"participation by multiple subjects.(2)Through the"action-efficiency-target"system,the comprehensive governance analysis framework of"matter-organization-ownership"in rural space provides an effective scheme for constructing rural spatial *** spatial governance is characterized by both rigidity and flexibility,the interaction between physical space and spatial relationships,and the superposition of spatial ownership and spatial organization.(3)The rural spatial governance features of interconnecting various scales(regional–village–plot)are conducive to improving the rural spatial governance system.(4)The governance means,participation modes,and value-sharing mechanisms of rural spatial governance help enrich the territorial spatial planning system,promote the integration of multiple regulations,refine the regulation of land use,and

关键词： rural spatial restructuring rural revitalization spatial governance village planning territorial spatial planning

Sources of nitrous and nitric oxides in paddy soils: Nitrification and denitrification

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Journal of Environmental Sciences 2014年第3期26卷 581-592页

作者： Ting Lan Yong Han Marco Roelcke Rolf Nieder Zucong Cai State Key Laboratory of Soil and sustainable Agriculture Institute of Soil Science Chinese Academy of Sciences Institute of Geoecology Technische Universitt Braunschweig school of geography Sciences Nanjing Normal University

Rice-paddies are regarded as one of the main agricultural sources of N 2O and NO emissions. To date, however, specific N2O and NO production pathways are poorly understood in paddy soils. ^15N-tracing experiments were carded out to investigate the processes responsible for N2O and NO production in two paddy soils with substantially different soil properties. Laboratory incubation experiments were carried out under aerobic conditions at moisture contents corresponding to 60% of water holding capacity. The relative importance of nitrification and denitrification to the flux of NaO was quantified by periodically measuring and comparing the enrichments of the N2O, NH^-N and NO3-N pools. The results showed that both N2O and NO emission rates in an alkaline paddy soil with clayey texture were substantially higher than those in a neutral paddy soil with silty loamy texture. In accordance with most published results, the ammonium N pool was the main source of N2O emission across the soil profiles of the two paddy soils, being responsible for 59.7% to 97.7% of total N2O emissions. The NO3-N pool of N2O emission was relatively less important under the given aerobic conditions. The rates of N2O emission from nitrification （N2On） among different soil layers were significantly different, which could be attributed to both the differences in gross N nitrification rates and to the ratios of nitrified N emitted as NzO among soil layers. Furthermore, NO fluxes were positively correlated with the changes in gross nitrification rates and the ratios of NO/N2O in the two paddy soils were always greater than one （from 1.26 to 6.47）. We therefore deduce that, similar to N2O, nitrification was also the dominant source of NO in the tested paddy soils at water contents below 60% water holding capacity.

关键词： ^15N tracing model N2O NO NO/N2O nitrification denitrification

Dynamic evolution and the mechanism of modern gully agriculture regional function in the Loess Plateau

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Journal of Geographical Sciences 2022年第11期32卷 2229-2250页

作者： QU Lulu LI Yurui WANG Yongsheng DONG Shijie WEN Qi school of Public Policy and Administration Chongqing UniversityChongqing 400044China Institute of Geographic Sciences and Natural Resources Research CASBeijing 100101China Key Laboratory of Regional sustainable development Modeling CASBeijing 100101China school of geography and Planning Ningxia UniversityYinchuan 750021China

The agricultural regional type and function are the key theoretical issues in agricultural geography *** agriculture in the Loess Plateau is a new regional type of agricultural system with the coupling development of the modern gully human-earth *** study of its functional changes is of great practical significance for food security,rural revitalization and sustainable development of regional agriculture in the region of *** paper analyses the multifunctional change of gully agriculture in the Loess Plateau and its dynamic mechanism by using large-scale remote sensing data,topographic relief amplitude model,and spatial econometric model to understand internal implications for evolution differentiation at the basin *** results show that:(1)The spatial concentration of production and supply function of agricultural products(APF)in the gully of the Loess Plateau gully is high,while the ecological conservation and maintenance function(ECF),employment and social security function(ESF),cultural heritage and leisure function(CRF)are relatively *** four functions’spatial distribution has revealed an apparent regularity.(2)APF has been significantly enhanced,which is mainly distributed in point clusters and strips in the farming and pastoral areas in northern Shaanxi to the Yanhe river *** high-value areas of ESF are clustered around the urbanized metropolitan circles and urban-rural staggered areas along the Great *** is concentrated in areas with significant natural endowments and excellent ecological *** is significantly higher in the municipal districts and the surrounding regional central cities.(3)There are noticeable differences in the gully agriculture regional function(GARF)evolution process due to the geographical environment and socio-economic development *** this regard,natural factors have tremendously affected APF,ESF,and ECF,while socio-economic factors greatly differ in the four functions

关键词： dynamic mechanism functional evolution gully human-earth system Loess Plateau modern gully agriculture transformation and development

Machine learning empowers efficient design of ternary organic solar cells with PM6 donor

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Journal of Energy Chemistry 2025年第1期 337-347页

作者： Kiran A.Nirmal Tukaram D.Dongale Santosh S.Sutar Atul C.Khot Tae Geun Kim school of Electrical Engineering Korea University Computational Electronics and Nanoscience Research Laboratory School of Nanoscience and Biotechnology Shivaji University Yashwantrao Chavan school of Rural development Shivaji University

Organic solar cells(OSCs) hold great potential as a photovoltaic technology for practical ***, the traditional experimental trial-and-error method for designing and engineering OSCs can be complex, expensive, and time-consuming. Machine learning(ML) techniques enable the proficient extraction of information from datasets, allowing the development of realistic models that are capable of predicting the efficacy of materials with commendable accuracy. The PM6 donor has great potential for high-performance OSCs. However, it is crucial for the rational design of a ternary blend to accurately forecast the power conversion efficiency(PCE) of ternary OSCs(TOSCs) based on a PM6 ***, we collected the device parameters of PM6-based TOSCs and evaluated the feature importance of their molecule descriptors to develop predictive models. In this study, we used five different ML algorithms for analysis and prediction. For the analysis, the classification and regression tree provided different rules, heuristics, and patterns from the heterogeneous dataset. The random forest algorithm outperforms other prediction ML algorithms in predicting the output performance of PM6-based TOSCs. Finally, we validated the ML outcomes by fabricating PM6-based TOSCs. Our study presents a rapid strategy for assessing a high PCE while elucidating the substantial influence of diverse descriptors.

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Structure and governance model of rural social space quality:A case study of Longxi County in the Loess Hilly Area of China

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Journal of Geographical Sciences 2022年第7期32卷 1297-1320页

作者： WU Shanshan MA Libang TAO Tianmin DOU Haojian College of geography and Environmental Science Northwest Normal UniversityLanzhou 730070China Key Laboratory of Resource Environment and sustainable development of Oasis Gansu ProvinceLanzhou 730070China Northwest Institute of Urban-Rural development and Collaborative Governance Lanzhou 730070China

The rural social space quality is an important indicator to measure the living standard and thinking ideas and so forth of rural residents in a certain *** this paper,213 administrative villages in Longxi County of the Loess Hilly Area,China are taken as evaluation units to construct the evaluation model of the rural social space *** paper deeply analyzed the variation patterns and their formation mechanism of the rural social space quality at a village scale,and proposed a governance model based on the rural social space *** results show that:(1)the social space quality levels of individual administrative villages show a gradually decreasing trend from the township seats to *** eastern part of Longxi County has a relatively high education level and living standard,and the western part has a relatively high population stability level and income level.(2)The rural social space quality is mainly in a ring structure,supplemented by the interlaced *** core area is the towns and their surrounding areas,while the transition area,marginal area,and other areas are expanded around the core area.(3)Social forces and spatial effects jointly shape the variation of the rural social space *** organizations provide a driving force for the allocation of elements,and interweaving with the spatial effects lead to the differences in the social space quality.(4)The governance models of the rural social space quality are constructed based on the principles of retaining the rural“people”,optimizing the rural“land”,and developing the rural“industry”,so as to improve the rural centripetal force,core force,inner thrust,and source power.

关键词： rural social space quality spatial structure formation mechanism governance model Longxi County in the Loess Hilly Area of China