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Spatiotemporal Pattern of Cultivated Land Pressure and Its Influencing Factors in the Huaihai Economic Zone, China

Chinese Geographical Science 2023年第2期33卷 287-303页

作者： li Yi FANG Bin LI Yurui FENG Weilun YIN Xu School of Geography Nanjing Normal UniversityNanjing 210023China Research Center of New Urbanization and Land Problem Nanjing Normal UniversityNanjing 210023China Jiangsu Provincial Geographic Information Resources Development and Utilization Cooperative Innovation Center Nanjing 210023China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Key Laboratory of Regional Sustainable Development Modeling Chinese Academy of SciencesBeijing 100101China School of Geographic Science Hebei Normal UniversityShijiazhuang 050024China

Cultivated land pressure represents a direct reflection of grain security. Existing relevant studies rarely approached the spatiotemporal pattern of cultivated land pressure or the spatial heterogeneity of its influencing factors from the level of economic zones.Taking the Huaihai Economic Zone(HEZ), China for case analysis, this study investigated the spatiotemporal pattern of cultivated land pressure in diverse periods from 2000 to 2018 based on a modified cultivated land pressure index and spatial correlation models. On this basis, it explored the influencing factors of the spatial differentiation of cultivated land pressure in the late stage of the study using geographical detector as well as multi-scale geographically weighted regression model. The results indicated that: 1) in the study period, the global cultivated land pressure index of the study area decreased gradually, but cultivated land pressure increased locally in a significant way, especially in the central and southern Shandong Province;2) the spatial pattern of cultivated land pressure manifested global clustering features. Hot and secondary-hot spots presented a narrowing and clustering trend, whereas cold and secondary-cold spots manifested a spreading and clustering trend;3) average slope, the proportion of non-grain crops, population urbanization rate, and multiple cropping index have significant effects on the spatial differentiation of cultivated land pressure. The former three factors were positively correlated with cultivated land pressure, and the last factor was negatively correlated with cultivated land pressure;and 4) the amount of cultivated land has increased in the central and southern Shandong Province through land consolidation which, nonetheless, failed to improve the grain production. In regards to major grain producing areas similar to the HEZ in China, the authors suggest that great importance should be given to the balance of the quality and quantity of cultivated land, the optimization of agricultural production factors an

关键词： cultivated land pressure spatiotemporal pattern influencing factors Huaihai Economic Zone China

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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 research.Gully agriculture in the Loess Plateau is a new regional type of agricultural system with the coupling development of the modern gully human-earth relationship.The 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 interest.This 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 level.The 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 low.The 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 basin.The high-value areas of ESF are clustered around the urbanized metropolitan circles and urban-rural staggered areas along the Great Wall.ECF is concentrated in areas with significant natural endowments and excellent ecological conditions.CRF 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 stages.In this regard,natural factors have tremendously affected APF,ESF,and ECF,while socio-economic factors greatly differ in the four functions.There are still differences in the driving mech

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

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Vegetation Restoration in Response to Climatic and Anthropogenic Changes in the Loess Plateau, China

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Chinese Geographical Science 2020年第1期30卷 89-100页

作者： QU Lulu HUANG Yunxin YANG lingfan LI Yurui Faculty of Geographical Science Beijing Normal UniversityBeijing 100875China Institute of Geographic Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China

A thorough understanding of the vegetation succession in relation to both climatic changes and anthropogenic activities is vital for the formulation of adaptation strategies that address potential ecosystem challenges.Various climatic factors such as temperature,precipitation,and solar radiation,as well as anthropogenic factors such as ecological engineering and population migration,will affect the conditions for vegetation.However,the relationships among various factors remain unclear and the response of vegetation to climate change and anthropogenic activities in the Loess Plateau of China has not been well established.This study investigated the spatio-temporal characteristics and relationships between vegetation coverage and climatic factors in the Loess Plateau for the period of 1985–2015.Further analysis separated the anthropogenic and climatic factors on vegetation succession based on residual analysis.The results showed that the normalized difference vegetation index(NDVI)followed a significant upward trend with annual change rates of 0.15%during 1985–2015.The trend of human-induced NDVI increase was consistent with the spatial distribution of increasing forest areas in the eastern part of the Loess Plateau.Eco-restoration projects were the main driving factors that promoted vegetation coverage on the Loess Plateau.Furthermore,these results demonstrated that migrants to cities in the Loess Plateau could relieve ecological pressures and promote vegetation restoration.Therefore,the government should strive to increase population mobility and restore vegetation to sustain this particularly fragile ecological environment.

关键词： vegetation restoration climate change anthropogenic activities Loess Plateau the Grain for Green Project

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Multi-heterointerfaces for selective and efficient urea production

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National Science Review 2023年第2期10卷 212-223页

作者： Danyan Zhang yurui Xue Xuchen Zheng Chao Zhang Yuliang li Institute of Chemistry Chinese Academy of Sciences University of Chinese Academy of Sciences Shandong Provincial Key Laboratory for Science of Material Creation and Energy Conversion Science Center for Material Creation and Energy Conversion School of Chemistry and Chemical EngineeringShandong University

A major impediment to industrial urea synthesis is the lack of catalysts with high selectivity and activity,which inhibits the efficient industrial production of urea.Here,we report a new catalyst system suitable for the highly selective synthesis of industrial urea by in situ growth of graphdiyne on the surface of cobalt-nickel mixed oxides.Such a catalyst is a multi-heterojunction interfacial structure resulting in the obvious incomplete charge-transfer phenomenon between a graphdiyne and metal oxide interface and multiple intermolecular interactions.These intrinsic characteristics are the origin of the high performance of the catalyst.Studies on the me chanism reve al that the catalyst could effectively optimize the adsorption/desorption capacities of the intermediate and promote direct C-N coupling by significantly suppressing by-product reactions toward the formation of H2,CO,N2and NH3.The catalyst can selectively synthesize urea directly from nitrite and carbon dioxide in water at room temperature and pressure,and exhibits a record-high Faradaic efficiency of 64.3%,nitrogen selectivity(Nurea-selectivity) of86.0%,carbon selectivity(Curea-selectivity) of ～100%,as well as urea yield rates of 913.2 μg h-1mgcat-1and remarkable long-term stability.

关键词： porous materials carbon materials multi-heterointerfaces urea synthesis high-performance conversion

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Optimizing field management to promote the ecologicalization of agriculture in loess hilly-gully region,China

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Journal of Geographical Sciences 2023年第5期33卷 1055-1074页

作者： HUANG Yunxin LI Yurui liU Yansui Institute of Geographic Sciences and Natural Resources Research CASBeijing100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing101408China National Observation and Research Station of Earth Critical Zone on the Loess Plateau in Shaanxi Xi’an710061China

Scientific field management is an important path to realize ecological production and sustainable development of agriculture.As the main content of field management,nitrogen(N)management is the key to balance the economic and ecological benefits of agricultural production.In the loess hilly-gully region,for the fragile ecological and social system,ecologicalization of agricultural production is an important direction to promote sustainable agricultural development.However,irrational fertilization has been one of the main constraint factors,hindering the ecologicalization of local agriculture.In order to solve the problem and prove the practical significance of field management to ecologicalization of agriculture,this study aimed at evaluating the effects of different N fertilization rates and timing using Root Zone Water Quality Model(RZWQM)and then optimizing the N management.Experiments were conducted from 2018 to 2019 in Yangjuangou watershed,loess hilly-gully region,to calibrate and validate the model.The root mean square error(RMSE)of soil water content,nitrate N concentration,above-ground biomass,leaf area index ranged from 10.5-13.5 mm,2.96-3.80 mg·kg^(−1),730.3-1273.9 kg·ha^(−1)and 0.26-0.38,respectively,with the agreement index(d)between observed and simulated values ranging between 0.88 to 0.98.Simulation results showed that N leaching in semi-arid areas was also quite high due to concentrated rainfall and loose soil,which had previously been neglected.When the fertilization rate decreased by 35%(applying the chemical fertilizer at rate of 245.7 kg N ha^(−1))of typical fertilization(applying the chemical fertilizer at rate of 378.0 kg N ha^(−1)),the leaching and residual N decreased by 72.2%-75.4%and 35.6%-50.9%,respectively,while NUE increased by 41.5%-45.2%with no reduction in maize yield.Additionally,compared with applying additional N at seedling stage in one batch,applying at seedling and jointing stages in two batches further decreased N leaching and improved NUE.Thus,a 35%reduction of typical fer

关键词： field management nitrogen fertilization ecologicalization of agriculture gully agriculture loess hilly-gully region

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Bismuth/Graphdiyne Heterostructure for Electrocatalytic Conversion of CO_(2) to Formate

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Chemical Research in Chinese Universities 2022年第6期38卷 1380-1386页

作者： DU Yuncheng ZHENG Xuchen XUE yurui li Yuliang Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing100029P.R.China Institute of Chemistry Chinese Academy of SciencesBeijing100190P.R.China Science Center for Material Creation and Energy Conversion School of Chemistry and Chemical EngineeringInstitute of Frontier and Interdisciplinary ScienceShandong UniversityJinan250100P.R.China School of Chemical Science University of Chinese Academy of SciencesBeijing100049P.R.China

Electrocatalytic CO_(2) reduction is great promising in alleviating the excessive CO_(2) emission and the conversion to valuable productions.Herein we report the in-situ controlled growth of Bismuth nanoflower/graphdiyne heterostructures(Bi/GDY)for efficient CO_(2) conversion toward formate.Based on GDY,the obtained electrocatalyst exhibits a partial current density of 19.2 mA/cm^(2) and high reaction selectivity towards formate with a high Faradic efficiency of 91.7%at−1.03 V vs.RHE,and an energy efficiency of 58.8%.The high formate yield rates could be maintained at around 300µ.mol/(cm^(2)·h)over a wide potential range.Detailed characterizations show that the unique interface structures between GDY and Bi can enhance the charge transfer ability,increase the number of active sites,and improve the long-term stability,and finally reach high-performance electrocatalytic conversion of CO_(2) to formate.

关键词： Graphdiyne(GDY) Heterostructure CO_(2)reduction reaction(CO_(2)RR) Formate

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Differentiation regularity of urban-rural equalized development at prefecture-level city in China

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Journal of Geographical Sciences 2015年第9期25卷 1075-1088页

作者： liU Yansui CHEN Cong LI Yurui Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China College of Resources Science and Technology Beijing Normal University Beijing 100875 China University of Chinese Academy of Sciences Beijing 100049 China

The urban-rural equalized development （URED） as a definite measure and operating model is beneficial to gradually eliminating the dual-track structure of urban-rural development, bridging the gap of urban-rural development, and creating harmonious urban-rural interactions. This paper aims to explore the status quo of URED in China at prefecture level, and to reveal the spatio-temporal patterns of URED and its differentiation regularity. The results show that：（1） China＇s URED level can be categorized into two parts, i.e., the eastern and the western, according to the ＂HU Huanyong line＂, presenting a pattern of ＂east high and west low＂ and the URED level improves on the whole with the increase of distance from the line; （2） China＇s URED level can also be categorized into the northern and the southern parts according to ＂Kunlun-Qinling-Huaihe line＂, presenting a pattern of ＂north high and south low＂, and the URED level reduces on the whole with the increase of distance from the line; （3） At the national level, China＇s URED has a significant trend of spatial agglomeration, the high and low URED regions tend to be adjacent, namely, the URED level presents obvious regional unbalance; （4） The five sub-dimension indicators of the URED level in the geographical space also reveal similar regional differentiation pattern, and in the aspect of space a decreasing trend is found in the URED level from the eastern （northern coast, eastern coast and southern coast）, the northeastern, the central （the middle reaches of the Yangtze River and the Yellow River） to the western （northwest and southwest）; and （5） China＇s URED at prefecture-level city can be divided into five types of differentiation areas. This study contributes to promoting the integrative cognition of the status quo of China＇s URED and can serve as a scientific ref- erence concerning the decision-making of coordinating urban-rural development and of pushing forward new-type urbanization strategy in China.

关键词： urban-rural equalized development urban-rural development transformation urbanization rural disease differentiation regularity China

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GIS-based Effect Assessment of Soil Erosion Before and After Gully Land Consolidation: A Case Study of Wangjiagou Project Region, Loess Plateau

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Chinese Geographical Science 2015年第2期25卷 137-146页

作者： liU Yansui GUO Yanjun LI Yurui li Yuheng College of Resources Science and Technology Beijing Normal University Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences University of Chinese Academy of Sciences

The Loess Plateau is one typical area of serious soil erosion in the world. China has implemented ′Grain for Green′(GFG) project to restore the eco-environment of the Loess Plateau since 1999. With the GFG project subsidy approaching the end, it is concerned that farmers of fewer subsidies may reclaim land again. Thus, ′Gully Land Consolidation Project′(GLCP) was initiated in 2010. The core of the GLCP was to create more land suitable for farming in gullies so as to reduce land reclamation on the slopes which are ecological vulnerable areas. This paper aims to assess the effect of the GLCP on soil erosion problems by studying Wangjiagou project region located in the central part of Anzi valley in the middle of the Loess Plateau, mainly using the revised universal soil loss equation(RUSLE) based on GIS. The findings show that the GLCP can help to reduce soil shipment by 9.87% and it creates more terraces and river-nearby land suitable for farming which account for 27.41% of the whole study area. Thus, it is feasible to implement the GLCP in places below gradient 15°, though the GLCP also intensifies soil erosion in certain places such as field ridge, village land, floodplain, natural grassland, and shrub land. In short, the GLCP develops new generation dam land and balances the short-term and long-term interests to ease the conflicts between economic development and environmental protection. Furthermore, the GLCP and the GFG could also be combined preferably. On the one hand, the GFG improves the ecological environment, which could offer certain safety to the GLCP, on the other hand, the GLCP creates more farmland favorable for farming in gullies instead of land reclamation on the slopes, which could indirectly protect the GFG project.

关键词：土地整理黄土高原土壤侵蚀效果评估 GIS 项目区通用土壤流失方程生态脆弱地区

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Dynamic trends and driving forces of land use intensification of cultivated land in China

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Journal of Geographical Sciences 2015年第1期25卷 45-57页

作者： WANG Guogang liU Yansui LI Yurui CHEN Yangfen Institute of Agricultural Economics and Development CAAS Beijing 100081 China Institute of Geographic Sciences and Natural Resources Research CAS Beijing 100101 China

The aim of this study is to establish several important factors representing land use intensification in cultivated land （denoted by Cli）, using a multi-dimensional approach to achieve realistic and practical cultivated land use policies in China. For this reason, the theoretical framework was first built to explain the changes of land use intensification in the cultivated land, and then the variables and index were further developed for the purpose of characterizing the dynamic trends and driving forces of the land use intensification in the cultivated land at the provincial level. The study results indicate that the extent of Cll significantly increased during the period of 1996 to 2008, due to the extensive use of fertilizers, machinery and pesticide, increased labor and capital input, and intensified land use. Moreover, the principal component regression results show that the productivity of cultivated land, economic benefits of cultivated land, labor productivity, and land use conversion are the main factors affecting the village development. The first three factors play a positive role, while the last one has a negative effect on the land use intensification in the cultivated land. According to these results, the main policies for sustainable intensification in cultivated land are proposed. First, the sustainable pathways for intensification should be adopted to reduce the unsustainable uses of chemical fertilizer, agricultural chemicals, etc. Second, the conditions for agricultural production should be further improved to increase the cultivated land productivity. Third, it is very necessary and helpful for improving labor productivity and land use efficiency from the viewpoint of accelerated the cultivated land circulation. The last step is to positively affect the production activities of peasants by means of reforming the subsidy standards.

关键词： cultivated land land use intensification spatial pattern factors China

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Controlled Growth of Multidimensional Interface for High-Selectivity Ammonia Production

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CCS Chemistry 2023年第7期5卷 1653-1662页

作者： Xuchen Zheng yurui Xue Chao Zhang Yuliang li CAS Key Laboratory of Organic Solids Institute of ChemistryChinese Academy of SciencesBeijing 100190 School of Chemical Sciences University of Chinese Academy of SciencesBeijing 100190 Science Center for Material Creation and Energy Conversion School of Chemistry and Chemical EngineeringInstitute of Frontier and Interdisciplinary ScienceJinan 250100

The efficient production of ammonia by reducing nitrates at room temperature and ambient pressure is a promising alternative to the Haber-Bosch process and can effectively overcome the attendant water pollution issues.Herein,a new idea has been realized for rational and selective construction of the sp-carbon-metal-carbon interface,comprised of electronic-donating triple bonds in graphdiyne and electron-withdrawing iron carbides,for a highly efficient nitrate reduction reaction.The as-prepared sp-carbon-metal-carbon interfacial structures greatly increase the charge transfer ability and electrical conductivity of the system.The proposed concept of incomplete charge transfer has demonstrated significantly high selectivity,activity,and stability in catalytic system.The catalyst exhibits high Faradaic efficiency of over>95%and a NH3 yield rate up to 205.5μmolNH_(3) cm^(-2) h^(-1) in dilute nitrate conditions without any contaminant.

关键词： graphdiyne donor-acceptor interface incomplete charge transfer high selectivity ammonia production

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