Agricultural Non-point Source Pollution in China:Evaluation,Convergence Characteristics and Spatial Effects

In this study,an inventory analysis approach was used to investigate the intensity of agricultural non-point source pollution(ANSP)and its spatial convergence at national and provincial levels in China from 1999 to 2017.On this basis,spatial factors affecting ANSP were explored by constructing a spatial econometric model.The results indicate that:1)The intensity of China's ANSP emission showed an overall upward trend and an obvious spatial difference,with the values being high in the eastern and central regions and relatively low in the western region.2)Significant spatial agglomeration was shown in China's ANSP intensity,and the agglomeration effect was increasing gradually.3)In the convergence analysis,a spatial lag model was found applicable for interpretation of the ANSP intensity,with the convergence rate being accelerated after considering the spatial factors but slower than that of regional economic growth.4)The spatial factors affecting the ANSP intensity are shown to be reduced by improving agricultural infrastructure investment,labor-force quality,and crop production ratio,while the expansion of agricultural economy scale and precipitation and runoff have positive impact on ANSP in the study region.However,agricultural research and development(R&D)investment showed no direct significant effect on the ANSP intensity.Meanwhile,improving the quality of the labor force would significantly reduce the ANSP intensity in the surrounding areas,while the precipitation and runoff would significantly increase the pollution of neighboring regions.This research has laid a theoretical basis for formulation and optimization of ANSP prevention strategies in China and related regions.

Measurement of Rural Inclusive Financial Development and Analysis of Spatial Effects on Anti-poverty

Based on two dimensions of supply and demand,we use six indicators to establish a rural inclusive financial development index and evaluate the development of China's rural inclusive finance. We use spatial panel data model to examine the relationship between financial inclusion and rural poverty. Results show that:( i) both the rural inclusive finance and rural residents' per capita consumption present spatial clustering feature and show significant spatial correlation;( ii) the development of rural inclusive finance has significant spatial effect on poverty alleviation along time and space dimensions. In this study,the paper puts forward policy recommendations on strengthening the rural financial resources flow and constructing diversified rural inclusive financial system.

Impact of digital economy development on carbon productivity:An empirical analysis based on threshold effect and spatial spillover effect

Utilizing provincial panel data from 2014 to 2020,this study employs a fixed effect model,a threshold effect model,and a spatial lag model to empirically examine the correlation between digital economic development and carbon productivity.The findings indicate that digital economic development significantly contributes to the enhancement of carbon productivity in the long term.Furthermore,through instrumental variable method,replacement of explanatory variables and other methods to test its endogeneity and stability,the results remain robust.In terms of regional heterogeneity,the impact of digital economic development on carbon productivity is less pronounced in the central and western regions compared to the eastern region.Additionally,further investigation reveals that industrial structure upgrading and science and technology investment level exhibit different threshold effects on the influence of digital economy development level on carbon productivity.Moreover,there is a significant spatial spillover effect of digital economy development on carbon productivity with H-H and L-L agglomeration spatial correlation.

The measurement of the spatial effects of Chinese regional carbon emissions caused by exports

Based on the multi-regional input-output analysis, this paper improves the four traditional input-output formulas about exports resulting in multi-regional carbon emissions spatial effects which include direct effect, indirect effect, spillover effect and feedback effect. And the latter two formulas are to measure the bidirectional influences of carbon emissions induced by regional exports between two regions. The results suggest that the direct effects of Chinese eight regions induced by national exports decreased from 1997 to 2010, and the indirect effects induced by national exports also decreased except the northern coastal region and the northwestern region in China. During this period, most of Chinese coastal regions had strong spillover effects induced by their own exports. The northern coastal region and the eastern coastal region had stronger feedback effects, while the southern coastal region had weaker feedback effects and Beijing-Tianjin region had the weakest feedback effect induced by their exports. All of the inland regions had strong feedback effects, especially for Northwest and Central China, induced by their exports. More attention should be paid to the inter-regional joint efforts in order to effectively achieve Chinese national carbon-reduction target.

Spatial spillover effects of transport infrastructure on regional economic growth

Spatial spillover effects,either positive or negative,of transport infrastructure,highways/expressways,etc.,on regional economic growth are proposed.Using the panel data for 11 cities of Zhejiang province from 1994 to 2003,a spatial production function is applied to examine the spatial spillovers which can be generated as a positive output spillover from the transport infrastructure between neighboring cities.Some spatial weighted matrices are adopted to define different neighboring cities to measure how easily factors or economic activities can migrate between regions.The estimation results show that the output elasticity of the highway infrastructure in 11 cities are all insignificant at a 5% significance level;hence,highway infrastructure in a region cannot explain the same region's economic growth.On the other hand,the highway infrastructure of other contiguous regions has positive spillover effects on a same region's economic growth.

The Spatial and Electronic Effects of Substituent Groups on the Thermal Curing of Bio-Based Benzoxazines

To explore the influence of substituent groups on thermally induced curing,eight new bio-based benzoxazines containing different substituent groups with different electron negativity and volumes were synthesized.The thermal curing of these bio-based benzoxazines was studied in detail.Combined with the curing reaction kinetics,simulation and calculation of Highest Occupied Molecular and Lowest Unoccupied Molecular values,the spatial and electronic effects of different substituent groups on the curing of benzoxazine was explored.It was found that when the substituent was located at the position directly connected to the N atom,the steric hindrance effect of the group was dominant.When the substituent group was located on the benzene ring connected to the O atom,both the electronic effect and the spatial effect influenced the curing of benzoxazine.When an electron-withdrawing group was connected ortho position to the O atom,the curing reaction was promoted due to the decreased electron cloud density of O-on the oxazine ring,making the C-O bond easier to break.When an electron-donating group was connected to the meta position of the O atom it also promoted the curing reaction,possibly because it increased the electron cloud density of the+CH2 reaction site and thereby facilitated electrophilic substitution via attack of+CH2 on the cross linking reaction centre.This work provides a deeper understanding of how spatial and electronic effects of substituents affect the curing of benzoxazine.

Three-dimensional numerical simulation and earth pressure analysis on double-row piles with consideration of spatial effects

As a new kind of technology in retaining structures, the characteristics of double-row piles are significantly affected by spatial effects. In this paper, double-row piles as a retaining structure are simulated numerically in three-dimension by finite element software PLAXIS 3D FOUNDATION. The behavior differences of piles in different positions around the foundation pit are analyzed. By changing the parameters, including the length-width ratio, the excavation depth, the distance between rows and the diameter of piles, the variations of the lateral deformation, the bending moment and the earth pressure around the piles are determined. The reasonable values of parameters and some suggestions with consideration of earth pressure are proposed for the design of double-row piles as a retaining structure. The results show that the lateral deformation and bending moment are the largest in the middle of long side of the foundation pit, which is identified as the most unfavorable position. It is indicated that the earth pressure between rows above pit bottom is close to active earth pressure, while the earth pressure between rows under pit bottom is close to static earth pressure. It is suggested that 1/2-2/3 of pile length, 0.6-1.2 m, 3d-6d, and 2d-2.5d be chosen as embedded depth of piles, diameter of piles, distance between rows, and distance between piles, respectively, where d is the pile diameter.

Characteristics and Spatial Effects of the Spatio-Temporal Pattern Evolution of Industrial Land in Xi'an

As an organic part of urban functions, industrial land is of great significance to the urban healthy and sustainable development. Although consensus has been reached on the evolutionary characteristics and spatial effects of industrial land, the influence mechanism of the evolution of industrial land on urban space still needs further exploration. Therefore, the evolution of industrial land in Xi’an from 2003 to 2019 is analyzed by the land use change matrixes, mixed degrees index, and sprawl index according to the multisource data. The results show that the scale change of industrial land is characterized by an inverted U-shaped curve and development zone-oriented spatial aggregation. Suburbanization, the conversion of agricultural land to industrial land in the suburbs, has intensified urban sprawl, resulting in more serious work-living imbalance and traffic congestion.Deindustrialization, the conversion of industrial land to residential, commercial, and business facilities land in the city center, has promoted urban sprawl, generated a large amount of construction waste, and caused a waste of resources. Based on the complex factors such as urban planning, land finance, and development zones, this study contributes to the research of the improvement of the rationality of urban land layout by revealing the influence mechanism of the evolution of industrial land on urban space.

Energy consumption,air quality,and air pollution spatial spillover effects:evidence from the Yangtze River Delta of China

Based on analysis of the theoretical impact of energy consumption on air quality,taking 20 heavily polluted cities in the Yangtze River Delta of China as the object,we construct a Spatial Dubin Model,and estimate the effect of energy consumption on air quality and the spatial spillover effects of air pollution.We come to the following conclusions:First,the regional air quality has significant spatial dependence and spatial heterogeneity.Second,under three kinds of spatial associated mode,energy consumption has a negative impact on air quality,and the air pollution arising from energy consumption has a negative intra-regional spillover effect.The effect is strongest under the spatial distance weight matrix,followed by the economic distance,and the adjacent spatial weight matrix,which are−0.7926,−0.4547,and−0.4539,respectively.Third,in addition,under the adjacent space and economic distance space matrix,energy consumption has a significant negative effect on air quality,and the inter-regional spillover effects are−0.1513 and−2.5736,respectively.Meanwhile,considering spatial distance and economic development,the inter-regional spillover effect is much larger than is the intra-regional spillover effect.In general,the total spillover effect is at−0.6053 and−3.0284.

Low-carbon technology innovation responding to climate change from the perspective of spatial spillover effects

China's technological efforts to tackle climate change have lasted for many years. It is necessary to test the effect of these efforts with quantitative method. To be exact, whether and how China's low-carbon technology innovation responds to climate change should be tested. Based on the2004-2015 panel data of 30 provinces in China, we use the method of ESDA analyzing the spatial correlation of China's low-carbon innovation technology. Furthermore, we use the spatial Durbin model empirically analyzing the spatial spillover effects. The results obtained are as follows: first,supply and demand of Chinese low-carbon innovation has some deviation in the spatial distribution. The low-carbon technology innovation as the supply factor shows the characteristics of expanding from the east to the west. Innovation in eastern China has always been the most active, but innovative activities in the middle and western China are gradually decreased.However, carbon emissions have the characteristics of moving westward, implying the change of technology demand different from technology supply. Second, China's low-carbon innovation actively responds to the trend of climate change, indicating China's technological efforts have paid off. However, the spatial spillover effects are not significant, showing that the efforts in each region of China still work for himself. Third, environmental regulation and market pull are important factors for low-carbon technology innovation. Among them, both supporting policy and inhibitory policy have significant impact on the local low-carbon technology innovation, but no significant spatial spillover effects. It shows that environmental policies in different regions are competitive and lack of demonstration effects. Economic growth and export as market pull have higher level of effect on low-carbon technology innovation for both local and adjacent areas.Some policy implications are proposed based on these results finally.

Seasonal and Spatial Variation of Radiative Effects of Anthropogenic Sulfate Aerosol

On the basis of the emission data of the industrial sulphur dioxide (SO_2) and observed climate fields over East Asia, the distribution of anthropogenic sulfate aerosol(SO_4~2-) with seasonal variation in the troposphere is simulated and analyzed by a regional sulfur transport model, and the direct radiative effects of SO_4~2- under different weather conditions are also calculated using the discrete ordinate method. The results show that the concentration of SO_4~2- has significant seasonal and spatial variations resulting from the effects of SO_2 emission source and precipitation and wind fields. Both the concentration of SO_2 and its radiative forcing have the largest values in October and the lowest in July. SO_4~2- causes the decrease of the radiation flux absorbed by earth-atmosphere and the cooling of air temperature by scattering more solar radiation back into space. Besides, the radiative and climatic effects of SO_4~2- are related to the types and height and optical thickness, etc., of the clouds.

Does the digital economy contribute to carbon emissions reduction?A city-level spatial analysis in China

The rapid development of the digital economy provides an unprecedented opportunity for China to achieve carbon neutrality by 2060.While previous studies have explored the relationship between the digital economy,digital technologies,and energy,the impact of the digital economy on carbon emissions has not received sufficient attention in the literature.Meanwhile,although cities are the basic units for carbon emission reduction policies,few studies have explored carbon emissions at the city level in China.This study investigates the spatial correlation and spillover effects of the digital economy development on carbon emission reduction in 248 prefecture-level cities in China from 2011 to 2019.The proposed approach relies on Moran’s I test and the spatial Durbin model(SDM).First,the study’s results show that carbon emissions are more severe in industry-intensive cities in northeast and central China than in the eastern coast during the sample period.Second,the development of the digital economy is conducive to reducing carbon emissions.Third,Moran’s I and SDM tests find that the digital economy has a significant spatial effect on carbon emissions,with a close spatial connection between cities.Based on the above findings,this study offers relevant policy recommendations and suggestions for realizing China's carbon neutrality goal.

Evolution and Determinants of Population Agglomeration in Less Developed Metropolitan Areas:A Case Study of the Taiyuan Metropolitan Area,China

It is of importance to enhance the urban areas'capacity for population aggregation in underdeveloped regions,aiming to rectify the imbalanced and insufficient pattern of economic development in China.Taking the Taiyuan Metropolitan Area(TMA)in central China as a case study,this paper examines the evolutionary process and characteristics of population agglomeration from 2000 to 2020,and identifies factors associated with agglomeration and their spatial effects.The findings indicated that:1)against the background of sustained population shrinkage in the provincial area,the TMA showed a demographic trend of steady increase,albeit with a decelerated growth rate.In the metropolitan area,urban population size continued to grow rapidly,whereas the rural areas endured sustained losses.Disparities in city size continued to widen,and the polarization of concentrated population in the core cities kept increasing.2)Agglomerations in both secondary and service industries had significant positive effects on local population agglomeration,with the former effect being stronger.Regional economic development,government fiscal expenditure,and financial advancement all contributed to facilitating local population clustering.From a spatial spillover perspective,service agglomeration and financial development promoted population agglomeration in surrounding areas.Conversely,fiscal expenditure inhibited such agglomeration.As for industrial agglomeration and regional economic development,their spatial spillover effects were non-significant.The results obtained reveal several policy implications aimed at enhancing the population agglomeration capacity of the metropolitan area in underdeveloped regions during the new era.

Scale dependence of forest fragmentation and its climate sensitivity in a semi-arid mountain:Comparing Landsat,Sentinel and Google Earth data

Landscape fragmentation is generally viewed as an indicator of environmental stresses or risks,but the fragmentation intensity assessment also depends on the scale of data and the definition of spatial unit.This study aimed to explore the scale-dependence of forest fragmentation intensity along a moisture gradient in Yinshan Mountain of North China,and to estimate environmental sensitivity of forest fragmentation in this semi-arid landscape.We developed an automatic classification algorithm using simple linear iterative clustering(SLIC)and Gaussian mixture model(GMM),and extracted tree canopy patches from Google Earth images(GEI),with an accuracy of 89.2%in the study area.Then we convert the tree canopy patches to forest category according to definition of forest that tree density greater than 10%,and compared it with forest categories from global land use datasets,FROM-GLC10 and GlobeLand30,with spatial resolutions of 10 m and 30 m,respectively.We found that the FROM-GLC10 and GlobeLand30 datasets underestimated the forest area in Yinshan Mountain by 16.88%and 21.06%,respectively;and the ratio of open forest(OF,10%<tree coverage<40%)to closed forest(CF,tree coverage>40%)areas in the underestimated part was 2:1.The underestimations concentrated in warmer and drier areas occupied mostly by large coverage of OFs with severely fragmented canopies.Fragmentation intensity of canopies positively correlated with spring temperature while negatively correlated with summer precipitation and terrain slope.When summer precipitation was less than 300 mm or spring temperature higher than 4℃,canopy fragmentation intensity rose drastically,while the forest area percentage kept stable.Our study suggested that the spatial configuration,e.g.,sparseness,is more sensitive to drought stress than area percentage.This highlights the importance of data resolution and proper fragmentation measurements for forest patterns and environmental interpretation,which is the base of reliable ecosystem predictions with regard to the future climate scenarios.

Synergistic dance of digital economy and green finance on carbon emissions:Insights from China

China has recently implemented a dual-carbon strategy to combat climate change and other environmental issues and is committed to modernizing it sustainably.This paper supports these goals and explores how the digital economy and green finance intersect and impact carbon emissions.Using panel data from 30 Chinese provinces over the period 2011-2021,this paper finds that the digital economy and green finance can together reduce carbon emissions,and conducts several robustness tests supporting this conclusion.A heterogeneity analysis shows that these synergistic effects are more important in regions with low levels of social consumption Meanwhile,in the spatial dimension,the synergistic effect of the local digital economy and green finance adversely impacts the level of carbon emissions in surrounding areas.The findings of this paper provide insights for policymakers in guiding capital flow and implementing carbon-reduction policies while fostering the growth of China’s digital economy and environmental sustainability.

Comparative Analysis of Energy Characteristics of Two Southwest Vortices in Sichuan Under Similar Circulation Backgrounds

Based on ERA5 reanalysis data,the present study analyzed the thermal energy development mechanism and kinetic energy conversion characteristics of two extreme rainstorm processes in relation to the shallow southwest vortex in the warm-sector during a“rain-generated vortex”process and the deep southwest vortex in a“vortex-generated rain”process.The findings were as follows:(1)During the extreme rainstorm on August 11,2020(hereinafter referred to as the“8·11”process),intense surface heating and a high-energy unstable environment were observed.The mesoscale convergence system triggered convection to produce heavy rainfall,and the release of latent condensation heat generated by the rainfall promoted the formation of a southwest vortex.The significant increase(decrease)in atmospheric diabatic heating and kinetic energy preceded the increase(decrease)in vorticity.By contrast,the extreme rainstorm on August 16,2020(hereinafter referred to as the“8·16”process)involved the generation of southwest vortex in a low-energy and highhumidity environment.The dynamic uplift of the southwest vortex triggered rainfall,and the release of condensation latent heat from rainfall further strengthened the development of the southwest vortex.The significant increase(decrease)in atmospheric diabatic heating and kinetic energy exhibited a delayed progression compared to the increase(decrease)in vorticity.(2)The heating effect around the southwest vortex region was non-uniform,and the heating intensity varied in different stages.In the“8·11”process,the heating effect was the strongest in the initial stage,but weakened during the vortex's development.On the contrary,the heating effect was initially weak in the“8·16”process,and intensified during the development stage.(3)The available potential energy of the“8·11”process significantly increased in kinetic energy converted from rotational and divergent winds through baroclinic action,and the divergent wind energy continued to convert into rotational wind energy.By contrast,the“8·16”process involved the conversion of rotational wind energy into divergent wind energy,which in turn converted kinetic energy back into available potential energy,thereby impeding the further development and maintenance of the southwest vortex.

Influence of Information Technology on Social Spatial Behaviors of Urban Residents——Case of Nanjing City in China

Taking Nanjing as a case, the paper explains the spatial behavior differences existing in the information technology use among different groups of residents and households, by virtue of analyzing the survey data of urban households in the 11 districts of Nanjing, from the social, spatial, life and other non-technical angles. Also it makes various analyses and evaluation quantitatively and qualitatively on the social and spatial effect of information technology. The results show that the new technology is changing the social spatial behaviors of urban residents. New behavioral spaces of urban family such as telecommuting, email and QQ have begun to emerge. With the help of Internet, the communication scope of families has expanded greatly, and more new forms of publicizing community information have begun to emerge. Telecommunication contact forms have been developing swiftly, and their frequencies of contact have been increasing dramatically.

Spatial Effect of Mineral Resources Exploitation on Urbanization:A Case Study of Tarim River Basin,Xinjiang,China

Mineral resources exploitation significantly affects the spatial structure and evolutive trend of urbanization in arid areas.In this study,the spatial autocorrelation method and the spatial computation model were used to investigate the spatial impacts of mineral resources excavation and processing on comprehensive level of urbanization in the Tarim River Basin,Xinjiang,China for the years of 2000,2006 and 2008.The results are as follows:1)There was a spatial correlation of the development of mineral resources industry and the comprehensive level of urbanization in 2006 and 2008,with the spatial concentration trend rising significantly in 2006 and decreasing in 2008.2)The patterns of local spatial concentration of mineral resources industry and of the comprehensive level of urbanization were relatively stable,and the two patterns showed signs of spatial correlationship.The higher was the degree of the concentration of mineral resources industry,the stronger was its impact on the spatial clustering of urbanization.3)In 2000, mineral resources excavation and processing had a significant positive impact on the comprehensive level of urbanization in the region but not in its adjacent regions.However,in 2008,mineral resources excavation and processing significantly raised the comprehensive level of urbanization not only in the region but also in its neighboring regions.This research demonstrates that the development of mineral resources industry can strongly affect the trends and spatial patterns of urbanization.

Parametric modeling on spatial effect of excavation-damaged zone of underground cavern

Regarding excavation-damaged zone （EDZ） around underground opening as non-homogeneous rockmass with spatial deterioration effect on stuffiness and strength, a parametric model of EDZ using radius-displacement-dependent deformation modulus （RDDM） was proposed. Considering the nonlinearity characteristic of deformation and locality otherness of surrounding rock, deterioration parameter field of deformation modulus of rockmass around opening was quantitatively calculated through a given function. Applicability for multi-cavern condition and parameter sensibility of the model was analyzed by numerical experiments using synthetic data. Furthermore, the model was applied to identify EDZ of underground caverns of Pubugou hydropower station by calculating deterioration parameter field. Based on the parametric analysis of spatial effect and geological investigation, it is recognized that large radial deformation of deep fractured rock at the spandrel position and insufficient supporting bolts mainly result in great deformation pressure to act on the shotcrete and cause partial crack and spalling. It is shown that deterioration parameter field along the longitudinal axis of main powerhouse is evidently non-homogeneous in space and distributes exponentially along the radius from the opening. The model provides a simple and convenient way to identify the EDZ in the working state for rapid construction feedback analysis and support optimization of underground cavem from quantitative point of view and also aids in interpreting monitoring displacements and estimating support requirements.

Spatial Effect of Environmental Regulation on Carbon Emissions

Based on Chinese provincial panel data from 2003 to 2014,the spatial dependence between the environment regulation and carbon emissions is tested by spatial autocorrelation analysis. Besides,spatial lag model and spatial error model are built to empirically test the marginal effect of environmental regulation on carbon emissions and its spatial effect. The result shows that the influence trajectory of environmental regulation on carbon emissions performances inverted ＂ U＂ type. It is ＂ green paradox effect＂ before the inflection point and ＂ reversed transmission reduction effect＂ after the inflection point. Moreover,the carbon emissions show significant spatial spillover effect. In order to achieve the desired effect of environmental regulation and promote carbon reduction,we should increase the environmental regulation intensity reasonably,select rational environmental regulation policy tools,and sufficiently consider the spatial spillover effect of carbon emissions.