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.

Internal Polarization Field Induced Hydroxyl Spillover Effect for Industrial Water Splitting Electrolyzers

The formation of multiple oxygen intermediates supporting efficient oxygen evolution reaction(OER)are affinitive with hydroxyl adsorption.However,ability of the catalyst to capture hydroxyl and maintain the continuous supply at active sits remains a tremendous challenge.Herein,an affordable Ni2P/FeP2 heterostructure is presented to form the internal polarization field(IPF),arising hydroxyl spillover(HOSo)during OER.Facilitated by IPF,the oriented HOSo from FeP2 to Ni2P can activate the Ni site with a new hydroxyl transmission channel and build the optimized reaction path of oxygen intermediates for lower adsorption energy,boosting the OER activity(242 mV vs.RHE at 100 mA cm-2)for least 100 h.More interestingly,for the anion exchange membrane water electrolyzer(AEMWE)with low concentration electrolyte,the advantage of HOSo effect is significantly amplified,delivering 1 A cm^(-2)at a low cell voltage of 1.88 V with excellent stability for over 50 h.

Geospatial Analysis of Urban Heat Island Effects and Tree Equity

In recent decades, Urban Heat Island Effects have become more pronounced and more widely examined. Despite great technological advances, our current societies still experience great spatial disparity in urban forest access. Urban Heat Island Effects are measurable phenomenon that are being experienced by the world’s most urbanized areas, including increased summer high temperatures and lower evapotranspiration from having impervious surfaces instead of vegetation and trees. Tree canopy cover is our natural mitigation tool that absorbs sunlight for photosynthesis, protects humans from incoming radiation, and releases cooling moisture into the air. Unfortunately, urban areas typically have low levels of vegetation. Vulnerable urban communities are lower-income areas of inner cities with less access to heat protection like air conditioners. This study uses mean evapotranspiration levels to assess the variability of urban heat island effects across the state of Tennessee. Results show that increased developed land surface cover in Tennessee creates measurable changes in atmospheric evapotranspiration. As a result, the mean evapotranspiration levels in areas with less tree vegetation are significantly lower than the surrounding forested areas. Central areas of urban cities in Tennessee had lower mean evapotranspiration recordings than surrounding areas with less development. This work demonstrates the need for increased tree canopy coverage.

Research on the Impact of China’s Foreign Trade Technology Spillover on Green Total Factor Productivity of Countries Along the“Belt and Road”:Based on the Institutional Quality Threshold Effect

China’s growing trade with countries along the“Belt and Road”Initiative is accompanied by a focus on green development.Based on the panel data from 2007 to 2018,this paper establishes a threshold regression model to empirically analyze the institutional quality threshold effect of China’s foreign trade technology spillover on the GTFP of countries along the“Belt and Road.”The results show that China’s foreign trade technology spillover has a significant institutional quality double threshold effect on the green total factor productivity of the countries along the“Belt and Road.”As the institutional quality of the countries along the“Belt and Road”crosses a specific threshold value,the impact of China’s foreign trade technology spillover on the green total factor productivity of the countries along the“Belt and Road”has a significant positive promoting effect,and corresponding suggestions are put forward.

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.

Spillover effects and incentive initiatives of green behavior

Spillover effects play a crucial role in hindering the effective implementation of green behavior.Whether it pertains to enterprises or individuals,engaging in green behavior often leads to increased costs.However,the benefits derived from green behavior cannot be fully recouped but rather spill over and benefit other non-green entities,thereby undermining the incentives for companies or individuals to engage in green practices.The study categorizes the spillover effects of corporate green investment into three aspects based on the channels through which they occur:environmental spillover,inter-industry spillover(vertical spillover),and intra-industry spillover(horizontal spillover).While these three spillover mechanisms work in tandem with green behavior,existing literature has predominantly focused on the "free-rider " effect of environmental spillover and horizontal spillover,neglecting the impact of vertical spillover.Additionally,this paper provides a comprehensive review of measures aimed at incentivizing corporate green investment.Current government-level measures often overlook the multifaceted nature of spillover effects stemming from green behavior and the factors influencing corporate decision-making in this regard,resulting in various limitations and deficiencies.The paper argues that,besides relying solely on direct interventions from external actors such as the government or society,a more significant emphasis should be placed on enhancing the role of enterprises as a fundamental approach.This involves fostering the endogenous capacity of enterprises to generate green investment and facilitating a beneficial interaction that respects corporate autonomy.Consequently,policymakers should consider multiple dimensions of spillover effects and design appropriate mechanisms that leverage the inherent capabilities of enterprises,thus stimulating green investment.This approach represents a crucial area for future research that warrants further in-depth inve stigation.

Spatial emission reduction effects of China’s carbon emissions trading:quasi-natural experiments and policy spillovers

Insufficient assessment of emission reduction effects still exists in the carbon emission rights trading system,a major environmental regulation measure in China.Based on the data from the carbon trading pilot covering the years from 2007 to 2017,this study combined the synthetic control method with dynamic spatial Durbin model to comprehensively evaluate the spatial emission reduction effects of carbon trading policies.The results showed that:①The carbon trading policies promoted carbon emission reductions in the pilot regions,among which Tianjin and Hubei responded significantly,and also helped to suppress carbon emissions in the neighboring areas.②Long-term emission reduction effect from carbon emissions trading became gradually significant,while the indirect emission reduction effect was relatively weaker.③In term of reducing carbon emissions,the economic development channel played a key role,but it had a threat to the promotion of carbon emissions in the surrounding areas.Energy consumption was the main obstacle to the growth of carbon emissions.④In the long run,technological progress tended to become the key to the effective implementation of potential emission reduction effects of carbon trading policies.Based on the above findings,we suggest that the construction of a national carbon trading market should be promoted,the balanced development and orderly advancement of regional carbon trading markets should be paid attention to,the coordinated development of green economy as well as knowledge and technology exchange and cooperation among regions should be strengthened to form a low carbon development model among regions.

Research on the Spillover Effects of Digital Transformation on the Sustainable Growth of Green Schools

The development of society and the advancement of science and technology have led to the widespread integration of digital transformation in the field of education.However,the current establishment of green schools faces various challenges,including non-environmental building facilities,high renovation costs,low organizational management efficiency,high energy consumption,outdated office tools,and insufficient environmental awareness among teachers and students.Through thorough research and analysis,it becomes evident that digital technology can play a pivotal role in addressing these challenges and contribute to all aspects of green school establishment.The incorporation of digital thinking concepts is essential for the construction of ecologically civilized campuses and inclusive innovation.The process of digital design and transformation proves instrumental in optimizing both software and hardware facilities within the campus,thereby reducing energy consumption.Simultaneously,comprehensive digital teaching management enhances overall efficiency in management and service delivery.Innovative digital teaching and learning models emerge as transformative tools,providing new avenues to create low-carbon,green classrooms for both teachers and students.By exploring the application of digital transformation in establishing green schools and examining the resulting spillover effects,valuable insights can be gained.These insights,in turn,serve as reference points for building diversified digital technology paths on campus and fostering the creation of green schools.

Do companies influenced by smart cities pay more attention to green governance?Mechanism and optimal spatial correlation

Smart cities are a way for China to construct an innovative and environmentally conscious nation.The paper examines the impact of smart cities on corporate green governance and provides a theoretical foundation for formulating and executing smart city policy in China.Based on panel data from Chinese A-share listed companies in Shanghai and Shenzhen from 2008 to 2020,this study constructs a multiperiod double-difference model to examine the influence of smart cities on corporate green governance.Additionally,it uses a spatial double-difference model to investigate the spatial spillover effect of smart cities on neighboring areas.The findings indicate that smart cities effectively enhance corporate green governance.Analyzing the influencing mechanisms reveals that resource allocation efficiency,technological innovation,management environmental awareness,and regional environmental enforcement efforts act as mediators.Furthermore,the study reveals that the impact of smart cities on promoting corporate green governance is more pronounced in regions with lower levels of marketization and resource-based cities.Moreover,the research explores the spatial spillover effects of smart cities,with an effective radius of approximately 350 km.The optimal spatial correlation zone for green governance of businesses in neighboring areas in relation to smart cities is within a range of 250-350 km.This is manifested by the significant promotion of green governance in neighboring area businesses facilitated by smart cities.

Drivers for Inter-city Innovation Networks Across Chinese Cities:Modelling Physical Versus Intangible Effects

Cross-region innovation is widely recognized as an important source of the long-term regional innovation capacity.In the recent past,a growing number of studies has investigated the network structure and mechanisms of cross-region innovation collaboration in various contexts.However,existing research mainly focuses on physical effects,such as geographical distance and high-speed railway connections.These studies ignore the intangible drivers in a changing environment,the more digitalized economy and the increasingly solidified innovation network structure.Thus,the focus of this study is on estimating determinants of innovation networks,especially on intangible drivers,which have been largely neglected so far.Using city-level data of Chinese patents(excluding Hong Kong,Macao,and Taiwan Province of China),we trace innovation networks across Chinese cities over a long period of time.By integrating a measure on Information and Communications Technology(ICT)development gap and network structural effects into the general proximity framework,this paper explores the changing mechanisms of Chinese innovation networks from a new perspective.The results show that the structure of cross-region innovation networks has changed in China.As mechanisms behind this development,the results confirm the increasingly important role of intangible drivers in Chinese inter-city innovation collaboration when controlling for effects of physical proximity,such as geographical distance.Since digitalization and coordinated development are the mainstream trends in China and other developing countries,these countries'inter-city innovation collaboration patterns will witness dramatic changes under the influence of intangible drivers.

The Spatial Spillover Effect of Input and Output of Scientific Progress on Regional Economic Growth: The Case of Guangdong Province

This paper makes an empirical analysis of the spatial spillover effect of regional economic growth by using Moran’s I and Spatial Durbin Model to study the input and output of technological progress, with the panel data of 21 prefecture-level cities in Guangdong Province from 2008 to 2017. The empirical results show that the spatial autocorrelation exists in the economic development of Guangdong Province, and both the input and output of scientific research innovation have a significant positive effect on the regional economic growth. Under the spatial contiguity weights matrix, the output of scientific research and innovation has a more obvious spillover effect on the economic growth of neighboring cities than the input of scientific research and innovation.

Grey spatial solitons due to two-photon photorefractive effect

This paper predicts that grey spatial solitons can exist in two-photon photorefractive materials. In steady state and undcr appropriate external bias conditions, it obtains the grey spatial soliton solutions of the optical wave evolution equation. The intensity profile, phase distribution, and transverse velocity of these grey solitons are discussed.

Effects of temperature on screening bright-dark the stability of separate spatial soliton pair

We investigate theoretically the temperature effects on the evolution and stability of a separate screening brightdark soliton pair formed in a serial non-photovoltaic photorefractive crystal circuit. Our numerical results show that, for a stable bright-dark soliton pair originally formed in a crystal circuit at given temperatures, when one crystal temperature changes, the soliton supported by the other crystal will evolve into another stable soliton if the temperature change is quite small, whereas it will become unstable and experience larger cycles of compression or break up into beam filaments if the temperature difference is big enough. The dark soliton is more sensitive to the temperature change than the bright one.

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.

Spatial pattern of paulownia witches' broom and its effects on the growth of Paulownia elongata in Shaanxi Province,China

The spatial pattern of paulownia witches＇ broom was investigated using an Iwao＇s （m^＊-m） model in Shaanxi Province, China. Iwao＇s （m^＊-m） model revealed that spatial pattern of paulownia witches＇ broom exhibited a uniform distribution in sample plots. In this model, characteristics of contagiousness coefficient （a） justified the probability of infection by virus-transmission vectors. For tree age less than six, susceptible individuals were aggregated as clusters in the plots and then mutually repelled over age. A preliminary survey of stand volume show that from age five to six, stand volumes of disease grade II showed excessive vegetative growth and returned to normal level between ages ten and 11. Loss rate of volume increment with disease grade II decreased, and then returned to raising trend both at grades III and IV. This phenomenon is possibly caused by an over-compensation effect and by environmental factors. The redundancy of growth hormones in branches, shoots, leaves, buds and roots increased the stem volume of entire trees.

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.

Spatial Spillover and the Factors Influencing Public Service Supply in Sichuan Province, China

This article examines the spatial characteristics of public service supply and the factors influencing such supply in cities of Sichuan Province, China using spatial-autocorrelation and spatial econometric models with statistical data in 2012. The results demonstrate that expenditures on different types of public services present different spatial autocorrelation patterns. Although the spatial differences in basic public service expenditures are relatively small, a clear fan-shaped spillover to the east can be seen in Chengdu City. Chengdu also shows high clustering of advanced public service expenditures, being a typical core-periphery pattern. Post-earthquake reconstruction expenditures are clustered in the "5.12 Wenchuan earthquake" region and spill over toward cities to the east. The efficiency of public services in the mountainous areas in western Sichuan is low and exhibits a pattern of low-low spatial autocorrelation. The efficiency of public service supply is affected by economic, social, political and geographical factors. Based on the results of this analysis, we recommend a supply strategy that incorporates different types of public services and a specialized public service supply strategy for mountainous areas. Overall public service efficiency should be enhanced by focusing on narrowing the gap in farmers' income among regions and accelerating urbanization. Decision-makers should consider moresupportive policies with regard to providing basic public services in mountainous areas to ensure an equalized supply of basic public services. To enhance the efficiency of advanced public service supply, additional growth pole should be encouraged and incentivized; however, investments are required to drive the development of the peripheral regions through regional economic integration. Both software and hardware types of infrastructure are required to supply services efficiently during post-disaster reconstruction.

Volatility spillover effect between financial markets:evidence since the reform of the RMB exchange rate mechanism

The volatility spillover effect between the foreign exchange and stock markets has been a major issue in economic and financial studies.In this paper,GC-MSV model was used to study the spillover effect between the foreign exchange market and the stock market after the reform of the RMB exchange rate mechanism.The empirical results show that there is a negative correlation of dynamic price spillovers between the foreign exchange and stock markets.There are asymmetric volatility spillover effects between these two markets for both RMB stages—continued RMB appreciation or constant RMB shock(a significant reduction in appreciation).However,this has been reduced over time.In conclusion,The RMB exchange rate is a key variable that can affect the internal and external equilibrium of the national economy in an open economic environment,and the stock market is capable of quickly reflecting subtle changes in the real economy.In order to keep the stability of the financial markets and the healthy and rapid development of national economy,some suggestions were proposed.

Empirical research on the international spillover effects of U.S. monetary policy and their impacts

Empirical research has shown that there were international spillover effects from the U.S. monetary policy to output level, net exports and price levels of each country, and the impact on prices in each country was of synchronous effect. The structural impulse response analysis showed that U.S. monetary policy could improve U.S. income and payment without damaging U.S. economic growth, but the shocks negatively affected the economic growth in the rest of the world. Hence, it's important to pay close attention to the moral risks of U.S. monetary policy to evade the global shocks caused by the "benefit-itself-at-the-expense-of-others" polices of the American government. Besides these findings, U.S. monetary policy shocks strongly affect China's trade surplus fluctuations. Based on this, we propose that the approaches of balancing China's current account could be explored efficiently from the perspective of monetary policy.