Strategically improving carbon emission efficiency(CEE)through digital intelligence technology innovation(DITI)is imperative to capitalize on emerging opportunities for economic decarbonization and low-carbon green de...Strategically improving carbon emission efficiency(CEE)through digital intelligence technology innovation(DITI)is imperative to capitalize on emerging opportunities for economic decarbonization and low-carbon green development.This study employs panel data from 283 Chinese cities from 2011 to 2021 to examine the influence of DITI on urban CEE.The findings suggest the following:①DITI is crucial in enhancing CEE,and it exerts spatial spillover effects on neighboring areas.②Following the transition to a low-carbon energy system,DITI is instrumental in enhancing CEE by reducing the energy consumption scale,optimizing the energy consumption structure,and controlling the energy consumption intensity.③DITI has varying effects on CEE when subjected to multidimensional regulations,including fiscal pressure,fiscal decentralization,private economics,and entrepreneurial vitality.④The beneficial impact of DITI on CEE is more pronounced in regions with high economic growth,low natural resource endowments,high digital resource endowments,and in cities in central China.This study emphasizes DITI’s crucial role in promoting a low-carbon,green circular,and energy-efficient digital economy.展开更多
The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,expl...The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,exploring the provincial variations in carbon emission efficiency(CEE)in the building sector and identifying the effect of BEESs on CEE is crucial.This study focuses on commercial buildings in China and applies a difference in differences model to evaluate the impact of BEESs on the CEE of commercial buildings.The slacks-based measure–data envelopment analysis model is employed to assess the CEE of commercial buildings in 30 Chinese provinces from 2000 to 2019.Furthermore,heterogeneous tests are used to explore how climate characteristics and economic conditions affect the efficiency of BEESs.The results indicate that BEESs positively influence the CEE of commercial buildings.Specifically,a 1%increase in the intensity of BEESs causes a 0.1484%increase in the CEE of commercial buildings.Moreover,the impact of BEESs is particularly pronounced in the southern and western provinces.This study provides valuable scientific evidence for governments to enhance BEESs implementation.展开更多
Grasping the spatial correlation structure of transportation carbon emission efficiency(TCEE)and its influencing factors is significant for promoting high-quality and coordinated development of the transportation indu...Grasping the spatial correlation structure of transportation carbon emission efficiency(TCEE)and its influencing factors is significant for promoting high-quality and coordinated development of the transportation industry and the relevant region.Based on the ideal point cross-efficiency(IPCE)model,the social network analysis method was employed herein to explore the spatial correlation network structure of China’s provincial TCEE and its influencing factors.The results obtained showed the following outcomes.(1)During the study period,China’s provincial TCEE formed a complex and multithreaded network association relationship,but its network association structure was still relatively loose and presented the hierarchical gradient characteristics of dense in the east and sparse in the west.(2)The correlation of China’s TCEE formed a block segmentation based on the regional boundaries,and its factional structure was relatively obvious.The eastern region was closely connected with the central region,and generally connected with the western and northeastern regions.The central region was mainly connected with the eastern and western regions,and relatively less connected with the northeastern region.Besides,the northeastern region was weakly connected with the western region.(3)Shanghai,Beijing,Zhejiang,Guangdong,Jiangsu,Tianjin,and other developed provinces were in the core leading position in the TCEE network,which significantly impacted the spatial correlation of TCEE.However,Heilongjiang,Jilin,Xinjiang,Qinghai,and other remote provinces in the northeast and northwest were at the absolute edge of the network,which weakly impacted the spatial correlation of TCEE.(4)Provincial distance,economic development-level difference,transportation intensity difference,and transportation structure difference had significant negative impacts on the spatial correlation network of China’s provincial TCEE.In contrast,the energy-saving technology level difference had a significant positive impact on it.The regression coefficients of transportation energy structure and environmental regulation differences were positive but insignificant;their response mechanism and effects need to be improved and enhanced.展开更多
This paper uses an input-output table of China's provinces(2007-2016)to measure carbon emissions of these industries.It employs a Malmquist-Luenberger(ML)index with expected and undesired outputs,and an absoluteβ...This paper uses an input-output table of China's provinces(2007-2016)to measure carbon emissions of these industries.It employs a Malmquist-Luenberger(ML)index with expected and undesired outputs,and an absoluteβconvergence and a conditionalβconvergence model,to conduct an in-depth analysis of dynamic changes and spatial convergence.Carbon emission efficiency of forest processing industries in 25 regions,including Shanghai,Chongqing,Zhejiang,and Jiangsu are increasing,whereas those of Tianjin,Liaoning,Heilongjiang,and Xizang are decreasing.The main contributing factors of carbon emission efficiency in three major regions vary over time.Further,carbon emission efficiency in the eastern,central,and western regions all have absoluteβconvergence and conditionalβconvergence,indicating that different regions are developing toward their own goals and industry,yet regions with lower efficiency are catching up with those where with more efficient strategies in place.Finally,this paper proposes according recommendations.展开更多
To measure the carbon emission efficiency of China’s pharmaceutical manufacturing industry, explore the factors affecting the carbon emission efficiency of China’s pharmaceutical manufacturing industry, and provide ...To measure the carbon emission efficiency of China’s pharmaceutical manufacturing industry, explore the factors affecting the carbon emission efficiency of China’s pharmaceutical manufacturing industry, and provide reference for improving the carbon emission efficiency of China’s pharmaceutical manufacturing industry and promoting the government to formulate macro policies. Based on the data of the pharmaceutical manufacturing industry in 30 provinces of China from 2010 to 2019, and based on the SBM model and ML (Malmquist-Luenberger) index model, the carbon emission efficiency of the pharmaceutical manufacturing industry was calculated and its dynamic change was investigated, and the Tobit model was further used to explore the influencing factors of the carbon emission efficiency of the pharmaceutical manufacturing industry. The carbon emission efficiency of China’s inter-provincial pharmaceutical manufacturing industry has steadily improved. The carbon emission efficiency of the eastern region is higher than that of the western region, and that of the western region is higher than that of the central region. The eastern region is dominated by technological progress, and there is room for improvement in technological efficiency. The central and western regions are dominated by technological efficiency. Compared with technological efficiency, technological progress needs to be further improved. Environmental regulation, industrial agglomeration and technological innovation level positively affect carbon emission efficiency, while foreign investment level has no significant impact on carbon emission efficiency.展开更多
In the context of China’s resolute advancement of dual carbon goals(carbon peaking and carbon neutrality),urban agglomerations emerge as pivotal areas for carbon emission mitigation due to their dense economic activi...In the context of China’s resolute advancement of dual carbon goals(carbon peaking and carbon neutrality),urban agglomerations emerge as pivotal areas for carbon emission mitigation due to their dense economic activities and rapid urbanization.Previous studies overlook regional disparities in carbon emission prediction,disregarding the variations and policy directives across different provinces or cities.Therefore,this study addresses the research gap by investigating synergistic strategies to foster regional carbon peaking within the Beijing-Tianjin-Hebei region.Employing a novel approach tailored to regional segmentation policies,we provide more accurate predictions reflect-ing real-world conditions and distinct policy landscapes.Meanwhile,we integrate carbon emission efficiency into our analysis,emphasizing the dual goals of emission reduction and quality economic growth.Our empirical investigation in the Beijing-Tianjin-Hebei region,utilizing the Super-SBM and extended STIRPAT models,reveals upward trends in carbon emission efficiency,with varying trajectories across cities.Scenario simulations informed by the"14th Five-Year Plan"demonstrate that under the green development scenario,carbon peaking accelerates,alongside enhanced efficiency,supporting long-term emission reduction.Moreover,we design seven regional synergy carbon peak strate-gies for scenario simulations to facilitate the rational layout of dual carbon policies for collaborative development.We find that synergistic strategies have proven more effective in reducing regional carbon emission and increasing efficiency than strategies focusing solely on economic development or energy conservation.This innovative finding emphasizes the necessity of comprehensive green development in the Beijing-Tianjin-Hebei region and provides strong evidence for policymakers.Our research contributes to targeted strategies for improving carbon emission effi-ciency and reducing emissions,emphasizing the importance of synergistic approaches for regional carbon reduction.展开更多
The typical light emission efficiency behaviors of InGaN/GaN multi-quantum well （MQW） blue light- emitting diodes （LEDs） grown on c-plane sapphire substrates are characterized by pulsed current operation mode in t...The typical light emission efficiency behaviors of InGaN/GaN multi-quantum well （MQW） blue light- emitting diodes （LEDs） grown on c-plane sapphire substrates are characterized by pulsed current operation mode in the temperature range 40 to 300 K. At temperatures lower than 80 K, the emission efficiency of the LEDs decreases approximately as an inverse square root relationship with drive current. We use an electron leakage model to explain such efficiency droop behavior; that is, the excess electron leakage into the p-side of the LEDs under high forward bias will significantly reduce the injection possibility of holes into the active layer, which in turn leads to a rapid reduction in the radiative recombination efficiency in the MQWs. Combining the electron leakage model and the quasi-neutrality principle in the p-type region, we can readily derive the inverse square root dependent function between the light emission efficiency and the drive current. It appears that the excess electron leakage into the p-type side of the LEDs is primarily responsible for the low-temperature efficiency droop behavior.展开更多
Ternary metal halides based on Cu(I)and Ag(I)have attracted intensive attention in optoelectronic applications due to their excellent luminescent properties,low toxicity,and robust stability.While the self-trapped exc...Ternary metal halides based on Cu(I)and Ag(I)have attracted intensive attention in optoelectronic applications due to their excellent luminescent properties,low toxicity,and robust stability.While the self-trapped excitons(STEs)emission mechanisms of Cu(I)halides are well understood,the STEs in Ag(I)halides remain less thoroughly explored.This study explores the STE emission efficiency within the A_(2)AgX_(3)(A=Rb,Cs;X=Cl,Br,I)system by identifying three distinct STE states in each material and calculating their configuration coordinate diagrams.We find that the STE emission efficiency in this system is mainly determined by STE stability and influenced by self-trapping and quenching barriers.Moreover,we investigate the impact of structural compactness on emission efficiency and find that the excessive electron–phonon coupling in this system can be reduced by increasing the structural compactness.The atomic packing factor is identified as a low-cost and effective descriptor for predicting STE emission efficiency in both Cs_(2)AgX_(3) and Rb_(2)AgX_(3) systems.These findings can deepen our understanding of STE behavior in metal halide materials and offer valuable insights for the design of efficient STE luminescent materials.The datasets presented in this paper are openly available in Science Data Bank at https://doi.org/10.57760/sciencedb.12094.展开更多
Based on the target of energy-saving and emission reduction(ESER)in the national five-year plan in China,an extended directional distance function model(E-DDF)including undesirable input and undesirable output is prop...Based on the target of energy-saving and emission reduction(ESER)in the national five-year plan in China,an extended directional distance function model(E-DDF)including undesirable input and undesirable output is proposed,and energy-saving efficiency,emission reduction efficiency,ESER efficiency are defined.Then the weighted directional distance function model is constructed for the total factors efficiency index model of ESER to reflect its dynamic change.The results show that the ESER efficiency continues to rise during the three five-year plan periods(2006-2017),and the efficiency score of the east area are higher than those of central and west area.The disparity and change of energy-saving efficiency among difference regions are not obvious,but the disparity and change of emission reduction efficiency are the main reasons for the improvement and change of ESER efficiency index.In the long run,the ESER efficiency is in a dynamic upward trend,and the effect of technological progress is more obvious compared with technical efficient index.展开更多
Fabrication of efficient solid luminogens with tunable emission is both fundamentally significant and technically important. Herein, based on our previous strategy for the construction of efficient and multifunctional...Fabrication of efficient solid luminogens with tunable emission is both fundamentally significant and technically important. Herein, based on our previous strategy for the construction of efficient and multifunctional solid luminogens through the combination of diverse aggregation-induced emission （ALE） units with other functional moieties, a group of luminophores with electron donor-acceptor （D-A） structure and typical intramolecular charge transfer （ICT） characteristics, namely CZ-DCDPP, DPA-DCDPP and DBPA-DCDPP were synthesized and investigated. The presence of twisting and AlE-active 2,3- dicyano-S,6-diphenylpyrazine （DCDPP） moiety endows them highly emissive in the solid states, whereas the introduction of arylamines with varied electron-donating capacity and different conjugation render them with tunable solid emissions from green to red. While CZ-DCDPP and DPA-DCDPP solids exhibit distinct mechanochromism, both DPA-DCDPP and DBPA-DCDPP solids can generate efficient red emission. Owing to their high efficiency, remarkable thermal and morphological stabilities and moreover red emission, they are promising for diverse optoelectronic and biological applications.展开更多
Financial technology(FinTech)has emerged as a key policy instrument for transforming economic development models.Whether it can energize the low-carbon economy and enhance carbon emission efficiency(CEE)has drawn incr...Financial technology(FinTech)has emerged as a key policy instrument for transforming economic development models.Whether it can energize the low-carbon economy and enhance carbon emission efficiency(CEE)has drawn increasing scholarly attention.Using panel data from 278 Chinese cities(2006–2021),this study constructs a quasi-natural experiment and applies a difference-in-differences(DID)model to evaluate the policy effects of FinTech on CEE.Mediation and moderation models further explore the mechanisms underlying this relationship.The findings reveal that FinTech significantly improves CEE,generating policy dividends that advance low-carbon development.This conclusion remains robust under dual machine learning causal inference,propensity score matching DID,and other robustness tests.Financing constraints,innovation level,and industrial structure upgrading fully mediate the effect of FinTech on CEE,where financing constraints and innovation show positive mediation effects,while industrial structure upgrading has a negative one.Moreover,financial agglomeration weakens FinTech’s positive influence on CEE,and the effects differ across regions,development levels,and resource endowments.This study broadens the analytical framework connecting FinTech and CEE and deepens understanding of the mechanisms linking financial innovation to lowcarbon transition.展开更多
From 2000 to 2010 China experienced rapid economic development and urbanization.Many cities in economically developed areas have developed from a single-center status to polycentricity.In this study,we used explorator...From 2000 to 2010 China experienced rapid economic development and urbanization.Many cities in economically developed areas have developed from a single-center status to polycentricity.In this study,we used exploratory spatial data analysis (ESDA) to identify the population centers,which identified 232 cities in China as having urban centers.COMP was used to represent urban agglomeration,and POLYD (representing how far is the city’s sub-centers to the main center),POLYC (representing the number of a city’s centers),and POLYP (representing the population distributed between the main center and the sub-centers) were used to indicate urban polycentricity.Night light data were used to determine the CO2 emissions from various cities in China.A mixed model was used to study the impact of urban aggregation and polycentric data on the CO2 emission efficiency in 2000 and 2010.The study found that cities with higher compactness were distributed in coastal areas,and the cities with higher multicentricity were distributed in the Yangtze River Delta and Shandong Province.The more compact the city was,the less conducive it was to improving CO2 emission efficiency.Polycentric development of the city was conducive to improving the CO2 emission efficiency,but the number of urban centers had no significant relationship with the CO2 emission efficiency.Our research showed that the compactness and multicentricity of the city had an impact on the CO2 emission efficiency and provided some planning suggestions for the low carbon development of the city.展开更多
Transportation accounts for 80% of open-cut coal mine carbon emissions. With regard to the energy con- sumption and carbon emissions of transportation within an open-cut mine, this paper systematically compared the wo...Transportation accounts for 80% of open-cut coal mine carbon emissions. With regard to the energy con- sumption and carbon emissions of transportation within an open-cut mine, this paper systematically compared the work and energy consumption of a truck and belt conveyor on a theoretical basis, and con- structed a model to calculate the energy consumption of open-cut mine transportation. Life cycle carbon emission factors and power consumption calculation model were established through a Process Analysis- Life Cycle Analysis （PA-LCA）. The following results were obtained： （1） the energy consumption of truck transportation was four to twelve times higher than that of the belt conveyor; （2） the C02 emissions from truck transportation were three to ten times higher than those of the belt conveyor; （3） with the increase in the slope angle for transportation, the ratio of truck to belt conveyor for both energy consumption and carbon emissions gradually decreased; （4） based on 2013 prices in China, the energy cost of transportation using a belt conveyor in open-cut coal mines could save 0.6-2.4 Yuan/（t kin） compared to truck transportation.展开更多
Dust emission caused by wind erosion of soil is an important surface process in arid and semi-arid regions.However,existing dust emission models pay insufficient attention to the impacts of aerodynamic entrainment of ...Dust emission caused by wind erosion of soil is an important surface process in arid and semi-arid regions.However,existing dust emission models pay insufficient attention to the impacts of aerodynamic entrainment of particles.In addition,studies of wind erosion processes do not adequately account for the dynamics of wind erosion rates and dust emission fluxes,or for the impact of soil texture on dust emission.Our wind tunnel simulations of wind erosion and dust emission showed that the soil texture,wind erosion duration,and shear velocity are major factors that affect the dynamics of wind erosion and dust emission.Because of the limited supply of surface sand and the change in surface erosion resistance caused by surface coarsening during erosion,the wind erosion rate and the flux of particles smaller than 10μm(PM_(10))caused by aerodynamic entrainment decreased rapidly with increasing erosion duration,which suggests that surface wind erosion and dust emission occur primarily during the initial stage of wind erosion.The PM_(10) emission efficiency decreased with increasing shear velocity following a power function,and finer textured sandy loam soils had greater PM_(10) emission efficiency than loamy sand soils.展开更多
Currently, daylighting ducts system is widely used as a daylighting device. Generally, daylighting duct system efficiently takes light from outside during the day, and conveys daylight to required location through lig...Currently, daylighting ducts system is widely used as a daylighting device. Generally, daylighting duct system efficiently takes light from outside during the day, and conveys daylight to required location through light duct manufactured by high reflectance mirror. Daylighting duct system can convey daylight to underground space that has no windows opening to external space. Daylighting system is composed of light collection part, light guide part and light emission part. Efficiency of daylighting system is depending on type of each part used in the system. However, it is very difficult to estimate exact light flow in the system considering type of the parts. Authors performed measurement experiments to make clear the light flow with real-size model and miniature model of daylighting duct system. We discussed effect of type of the parts on efficiency of daylighting duct system.展开更多
Industrial coal-fired boiler is an important air pollutant emission source in China. The chain-grate boiler is the most extensively used type of industrial coal-fired boiler. An electrical low-pressure impactor, and a...Industrial coal-fired boiler is an important air pollutant emission source in China. The chain-grate boiler is the most extensively used type of industrial coal-fired boiler. An electrical low-pressure impactor, and a Dekati？ Low Pressure Impactor were applied to determine mass and number size distributions of PM10 at the inlet and the outlet of the particulate emission control devices at six coalfired chain-grate boilers. The mass size distribution of PM10 generated from coal-fired chain-grate boilers generally displays a bimodal distribution that contains a submicron mode and a coarse mode. The PM in the submicron mode for burning with raw coal contributes to 33% ± 10 % of PM10 emissions, much higher than those for pulverized boilers. And the PM in the submicron mode for burning with briquette contributes up to 86 % of PM10 emissions. Multiclones and scrubbers are not efficient for controlling PM10 emission. Their average collection efficiencies for sub-micron particle and super-micron particle are 34% and 78%, respectively. Operating conditions of industrial steam boilers have influence on PM generation. Peak of the submicron mode during normal operation period is larger than the start-up period.展开更多
基金supported by the National Science Foundation of China Youth Fund Project[Grant No.72204247].
文摘Strategically improving carbon emission efficiency(CEE)through digital intelligence technology innovation(DITI)is imperative to capitalize on emerging opportunities for economic decarbonization and low-carbon green development.This study employs panel data from 283 Chinese cities from 2011 to 2021 to examine the influence of DITI on urban CEE.The findings suggest the following:①DITI is crucial in enhancing CEE,and it exerts spatial spillover effects on neighboring areas.②Following the transition to a low-carbon energy system,DITI is instrumental in enhancing CEE by reducing the energy consumption scale,optimizing the energy consumption structure,and controlling the energy consumption intensity.③DITI has varying effects on CEE when subjected to multidimensional regulations,including fiscal pressure,fiscal decentralization,private economics,and entrepreneurial vitality.④The beneficial impact of DITI on CEE is more pronounced in regions with high economic growth,low natural resource endowments,high digital resource endowments,and in cities in central China.This study emphasizes DITI’s crucial role in promoting a low-carbon,green circular,and energy-efficient digital economy.
基金funded by the National Social Science Foundation of China[Grant No.23CJY018]the Fundamental Research Funds for the Central Universities[Grant No.JBK2406049]+2 种基金the National Natural Science Foundation of China[Grant No.72003151],[Grant No.72173100]the Soft Science Research Program of Sichuan Province[Grant No.2022JDR0227]Projects from the Research Center on Xi Jinping’s Economic Thought,and the Fundamental Research Funds for the“Guanghua Talent Program”of the Southwestern University of Finance and Economics.
文摘The building sector plays a crucial role in the worldwide shift toward achieving net-zero emissions.Building energy efficiency standards(BEESs)are highly effective policies for reducing carbon emissions.Therefore,exploring the provincial variations in carbon emission efficiency(CEE)in the building sector and identifying the effect of BEESs on CEE is crucial.This study focuses on commercial buildings in China and applies a difference in differences model to evaluate the impact of BEESs on the CEE of commercial buildings.The slacks-based measure–data envelopment analysis model is employed to assess the CEE of commercial buildings in 30 Chinese provinces from 2000 to 2019.Furthermore,heterogeneous tests are used to explore how climate characteristics and economic conditions affect the efficiency of BEESs.The results indicate that BEESs positively influence the CEE of commercial buildings.Specifically,a 1%increase in the intensity of BEESs causes a 0.1484%increase in the CEE of commercial buildings.Moreover,the impact of BEESs is particularly pronounced in the southern and western provinces.This study provides valuable scientific evidence for governments to enhance BEESs implementation.
基金This research was funded by the National Science Foundation under the Project“Synergic evolution mechanism of intercity transportation and metropolitan tourism spatial pattern”[Grant number.41771162]It was also funded by the National First-Class Discipline Development Project in Hunan Province under the category of“Geography”[Grang number.510002].
文摘Grasping the spatial correlation structure of transportation carbon emission efficiency(TCEE)and its influencing factors is significant for promoting high-quality and coordinated development of the transportation industry and the relevant region.Based on the ideal point cross-efficiency(IPCE)model,the social network analysis method was employed herein to explore the spatial correlation network structure of China’s provincial TCEE and its influencing factors.The results obtained showed the following outcomes.(1)During the study period,China’s provincial TCEE formed a complex and multithreaded network association relationship,but its network association structure was still relatively loose and presented the hierarchical gradient characteristics of dense in the east and sparse in the west.(2)The correlation of China’s TCEE formed a block segmentation based on the regional boundaries,and its factional structure was relatively obvious.The eastern region was closely connected with the central region,and generally connected with the western and northeastern regions.The central region was mainly connected with the eastern and western regions,and relatively less connected with the northeastern region.Besides,the northeastern region was weakly connected with the western region.(3)Shanghai,Beijing,Zhejiang,Guangdong,Jiangsu,Tianjin,and other developed provinces were in the core leading position in the TCEE network,which significantly impacted the spatial correlation of TCEE.However,Heilongjiang,Jilin,Xinjiang,Qinghai,and other remote provinces in the northeast and northwest were at the absolute edge of the network,which weakly impacted the spatial correlation of TCEE.(4)Provincial distance,economic development-level difference,transportation intensity difference,and transportation structure difference had significant negative impacts on the spatial correlation network of China’s provincial TCEE.In contrast,the energy-saving technology level difference had a significant positive impact on it.The regression coefficients of transportation energy structure and environmental regulation differences were positive but insignificant;their response mechanism and effects need to be improved and enhanced.
文摘This paper uses an input-output table of China's provinces(2007-2016)to measure carbon emissions of these industries.It employs a Malmquist-Luenberger(ML)index with expected and undesired outputs,and an absoluteβconvergence and a conditionalβconvergence model,to conduct an in-depth analysis of dynamic changes and spatial convergence.Carbon emission efficiency of forest processing industries in 25 regions,including Shanghai,Chongqing,Zhejiang,and Jiangsu are increasing,whereas those of Tianjin,Liaoning,Heilongjiang,and Xizang are decreasing.The main contributing factors of carbon emission efficiency in three major regions vary over time.Further,carbon emission efficiency in the eastern,central,and western regions all have absoluteβconvergence and conditionalβconvergence,indicating that different regions are developing toward their own goals and industry,yet regions with lower efficiency are catching up with those where with more efficient strategies in place.Finally,this paper proposes according recommendations.
文摘To measure the carbon emission efficiency of China’s pharmaceutical manufacturing industry, explore the factors affecting the carbon emission efficiency of China’s pharmaceutical manufacturing industry, and provide reference for improving the carbon emission efficiency of China’s pharmaceutical manufacturing industry and promoting the government to formulate macro policies. Based on the data of the pharmaceutical manufacturing industry in 30 provinces of China from 2010 to 2019, and based on the SBM model and ML (Malmquist-Luenberger) index model, the carbon emission efficiency of the pharmaceutical manufacturing industry was calculated and its dynamic change was investigated, and the Tobit model was further used to explore the influencing factors of the carbon emission efficiency of the pharmaceutical manufacturing industry. The carbon emission efficiency of China’s inter-provincial pharmaceutical manufacturing industry has steadily improved. The carbon emission efficiency of the eastern region is higher than that of the western region, and that of the western region is higher than that of the central region. The eastern region is dominated by technological progress, and there is room for improvement in technological efficiency. The central and western regions are dominated by technological efficiency. Compared with technological efficiency, technological progress needs to be further improved. Environmental regulation, industrial agglomeration and technological innovation level positively affect carbon emission efficiency, while foreign investment level has no significant impact on carbon emission efficiency.
基金supported by the grant from the National Natural Science Foundation of China(52270174).
文摘In the context of China’s resolute advancement of dual carbon goals(carbon peaking and carbon neutrality),urban agglomerations emerge as pivotal areas for carbon emission mitigation due to their dense economic activities and rapid urbanization.Previous studies overlook regional disparities in carbon emission prediction,disregarding the variations and policy directives across different provinces or cities.Therefore,this study addresses the research gap by investigating synergistic strategies to foster regional carbon peaking within the Beijing-Tianjin-Hebei region.Employing a novel approach tailored to regional segmentation policies,we provide more accurate predictions reflect-ing real-world conditions and distinct policy landscapes.Meanwhile,we integrate carbon emission efficiency into our analysis,emphasizing the dual goals of emission reduction and quality economic growth.Our empirical investigation in the Beijing-Tianjin-Hebei region,utilizing the Super-SBM and extended STIRPAT models,reveals upward trends in carbon emission efficiency,with varying trajectories across cities.Scenario simulations informed by the"14th Five-Year Plan"demonstrate that under the green development scenario,carbon peaking accelerates,alongside enhanced efficiency,supporting long-term emission reduction.Moreover,we design seven regional synergy carbon peak strate-gies for scenario simulations to facilitate the rational layout of dual carbon policies for collaborative development.We find that synergistic strategies have proven more effective in reducing regional carbon emission and increasing efficiency than strategies focusing solely on economic development or energy conservation.This innovative finding emphasizes the necessity of comprehensive green development in the Beijing-Tianjin-Hebei region and provides strong evidence for policymakers.Our research contributes to targeted strategies for improving carbon emission effi-ciency and reducing emissions,emphasizing the importance of synergistic approaches for regional carbon reduction.
基金supported by the National Natural Science Foundation of China(No.11074280)the Natural Science Foundation of Jiangsu Province,China(No.BK2012110)+3 种基金the Fundamental Research Funds for the Central Universities of China(No.JUSRP51323B)the Chinese Postdoctoral Science Foundation(No.2013M540437)the State Key Laboratory of ASIC and System(No.11KF003)the PAPD of Jiangsu Higher Education Institutions and the Summit of the Six Top Talents Program of Jiangsu Province(No.DZXX-053)
文摘The typical light emission efficiency behaviors of InGaN/GaN multi-quantum well （MQW） blue light- emitting diodes （LEDs） grown on c-plane sapphire substrates are characterized by pulsed current operation mode in the temperature range 40 to 300 K. At temperatures lower than 80 K, the emission efficiency of the LEDs decreases approximately as an inverse square root relationship with drive current. We use an electron leakage model to explain such efficiency droop behavior; that is, the excess electron leakage into the p-side of the LEDs under high forward bias will significantly reduce the injection possibility of holes into the active layer, which in turn leads to a rapid reduction in the radiative recombination efficiency in the MQWs. Combining the electron leakage model and the quasi-neutrality principle in the p-type region, we can readily derive the inverse square root dependent function between the light emission efficiency and the drive current. It appears that the excess electron leakage into the p-type side of the LEDs is primarily responsible for the low-temperature efficiency droop behavior.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.62125402 and 62321166653).
文摘Ternary metal halides based on Cu(I)and Ag(I)have attracted intensive attention in optoelectronic applications due to their excellent luminescent properties,low toxicity,and robust stability.While the self-trapped excitons(STEs)emission mechanisms of Cu(I)halides are well understood,the STEs in Ag(I)halides remain less thoroughly explored.This study explores the STE emission efficiency within the A_(2)AgX_(3)(A=Rb,Cs;X=Cl,Br,I)system by identifying three distinct STE states in each material and calculating their configuration coordinate diagrams.We find that the STE emission efficiency in this system is mainly determined by STE stability and influenced by self-trapping and quenching barriers.Moreover,we investigate the impact of structural compactness on emission efficiency and find that the excessive electron–phonon coupling in this system can be reduced by increasing the structural compactness.The atomic packing factor is identified as a low-cost and effective descriptor for predicting STE emission efficiency in both Cs_(2)AgX_(3) and Rb_(2)AgX_(3) systems.These findings can deepen our understanding of STE behavior in metal halide materials and offer valuable insights for the design of efficient STE luminescent materials.The datasets presented in this paper are openly available in Science Data Bank at https://doi.org/10.57760/sciencedb.12094.
基金supported by the National Social Science Fund of China(Grant No.18BTJ003).
文摘Based on the target of energy-saving and emission reduction(ESER)in the national five-year plan in China,an extended directional distance function model(E-DDF)including undesirable input and undesirable output is proposed,and energy-saving efficiency,emission reduction efficiency,ESER efficiency are defined.Then the weighted directional distance function model is constructed for the total factors efficiency index model of ESER to reflect its dynamic change.The results show that the ESER efficiency continues to rise during the three five-year plan periods(2006-2017),and the efficiency score of the east area are higher than those of central and west area.The disparity and change of energy-saving efficiency among difference regions are not obvious,but the disparity and change of emission reduction efficiency are the main reasons for the improvement and change of ESER efficiency index.In the long run,the ESER efficiency is in a dynamic upward trend,and the effect of technological progress is more obvious compared with technical efficient index.
基金supported by the National Natural Science Foundation of China (No. 51473092)the Shanghai Rising-Star Program (No. 15QA1402500)
文摘Fabrication of efficient solid luminogens with tunable emission is both fundamentally significant and technically important. Herein, based on our previous strategy for the construction of efficient and multifunctional solid luminogens through the combination of diverse aggregation-induced emission （ALE） units with other functional moieties, a group of luminophores with electron donor-acceptor （D-A） structure and typical intramolecular charge transfer （ICT） characteristics, namely CZ-DCDPP, DPA-DCDPP and DBPA-DCDPP were synthesized and investigated. The presence of twisting and AlE-active 2,3- dicyano-S,6-diphenylpyrazine （DCDPP） moiety endows them highly emissive in the solid states, whereas the introduction of arylamines with varied electron-donating capacity and different conjugation render them with tunable solid emissions from green to red. While CZ-DCDPP and DPA-DCDPP solids exhibit distinct mechanochromism, both DPA-DCDPP and DBPA-DCDPP solids can generate efficient red emission. Owing to their high efficiency, remarkable thermal and morphological stabilities and moreover red emission, they are promising for diverse optoelectronic and biological applications.
基金supported by the National Natural Science Foundation of China[Grant No.72371179]the Social Science Foundation of Jiangsu Province[Grant Nos.25GLB009 and 25ZXZD010]+3 种基金the Talent Cultivation Foundation of Southwest University of Science and Technology[Grant No.25sx7003]the Key Laboratory of Green Materials Development and Innovation[Grant No.LSCL-2502]the Major Special Project of the Sichuan Provincial Philosophy and Social Science Foundation[Grant No.SCJJ24ZD30]the Collaborative Innovation Center for New Urbanization and Social Governance of Soochow University.
文摘Financial technology(FinTech)has emerged as a key policy instrument for transforming economic development models.Whether it can energize the low-carbon economy and enhance carbon emission efficiency(CEE)has drawn increasing scholarly attention.Using panel data from 278 Chinese cities(2006–2021),this study constructs a quasi-natural experiment and applies a difference-in-differences(DID)model to evaluate the policy effects of FinTech on CEE.Mediation and moderation models further explore the mechanisms underlying this relationship.The findings reveal that FinTech significantly improves CEE,generating policy dividends that advance low-carbon development.This conclusion remains robust under dual machine learning causal inference,propensity score matching DID,and other robustness tests.Financing constraints,innovation level,and industrial structure upgrading fully mediate the effect of FinTech on CEE,where financing constraints and innovation show positive mediation effects,while industrial structure upgrading has a negative one.Moreover,financial agglomeration weakens FinTech’s positive influence on CEE,and the effects differ across regions,development levels,and resource endowments.This study broadens the analytical framework connecting FinTech and CEE and deepens understanding of the mechanisms linking financial innovation to lowcarbon transition.
基金supported by the National Natural Science Foundation of China (No.41671180)the Shenzhen Technology Plan (No.JCYJ20170412150910443)。
文摘From 2000 to 2010 China experienced rapid economic development and urbanization.Many cities in economically developed areas have developed from a single-center status to polycentricity.In this study,we used exploratory spatial data analysis (ESDA) to identify the population centers,which identified 232 cities in China as having urban centers.COMP was used to represent urban agglomeration,and POLYD (representing how far is the city’s sub-centers to the main center),POLYC (representing the number of a city’s centers),and POLYP (representing the population distributed between the main center and the sub-centers) were used to indicate urban polycentricity.Night light data were used to determine the CO2 emissions from various cities in China.A mixed model was used to study the impact of urban aggregation and polycentric data on the CO2 emission efficiency in 2000 and 2010.The study found that cities with higher compactness were distributed in coastal areas,and the cities with higher multicentricity were distributed in the Yangtze River Delta and Shandong Province.The more compact the city was,the less conducive it was to improving CO2 emission efficiency.Polycentric development of the city was conducive to improving the CO2 emission efficiency,but the number of urban centers had no significant relationship with the CO2 emission efficiency.Our research showed that the compactness and multicentricity of the city had an impact on the CO2 emission efficiency and provided some planning suggestions for the low carbon development of the city.
基金supported by the key project of the National Natural Science Foundation of China(No.51034005)the Research Fund for the Doctoral Program of Higher Education(the Specialized Research Fund for the Doctoral Program of Higher Education of China)(No.20100095110019)+1 种基金the National‘‘Twelfth Five-Year’’Plan for Science&Technology Support(No.2014BAC14B00)the National High Technology Research and Development Program of China(No.2012AA062004)
文摘Transportation accounts for 80% of open-cut coal mine carbon emissions. With regard to the energy con- sumption and carbon emissions of transportation within an open-cut mine, this paper systematically compared the work and energy consumption of a truck and belt conveyor on a theoretical basis, and con- structed a model to calculate the energy consumption of open-cut mine transportation. Life cycle carbon emission factors and power consumption calculation model were established through a Process Analysis- Life Cycle Analysis （PA-LCA）. The following results were obtained： （1） the energy consumption of truck transportation was four to twelve times higher than that of the belt conveyor; （2） the C02 emissions from truck transportation were three to ten times higher than those of the belt conveyor; （3） with the increase in the slope angle for transportation, the ratio of truck to belt conveyor for both energy consumption and carbon emissions gradually decreased; （4） based on 2013 prices in China, the energy cost of transportation using a belt conveyor in open-cut coal mines could save 0.6-2.4 Yuan/（t kin） compared to truck transportation.
基金supported by the National Natural Science Foundation of China(Nos.42077069 and U21A2001).
文摘Dust emission caused by wind erosion of soil is an important surface process in arid and semi-arid regions.However,existing dust emission models pay insufficient attention to the impacts of aerodynamic entrainment of particles.In addition,studies of wind erosion processes do not adequately account for the dynamics of wind erosion rates and dust emission fluxes,or for the impact of soil texture on dust emission.Our wind tunnel simulations of wind erosion and dust emission showed that the soil texture,wind erosion duration,and shear velocity are major factors that affect the dynamics of wind erosion and dust emission.Because of the limited supply of surface sand and the change in surface erosion resistance caused by surface coarsening during erosion,the wind erosion rate and the flux of particles smaller than 10μm(PM_(10))caused by aerodynamic entrainment decreased rapidly with increasing erosion duration,which suggests that surface wind erosion and dust emission occur primarily during the initial stage of wind erosion.The PM_(10) emission efficiency decreased with increasing shear velocity following a power function,and finer textured sandy loam soils had greater PM_(10) emission efficiency than loamy sand soils.
文摘Currently, daylighting ducts system is widely used as a daylighting device. Generally, daylighting duct system efficiently takes light from outside during the day, and conveys daylight to required location through light duct manufactured by high reflectance mirror. Daylighting duct system can convey daylight to underground space that has no windows opening to external space. Daylighting system is composed of light collection part, light guide part and light emission part. Efficiency of daylighting system is depending on type of each part used in the system. However, it is very difficult to estimate exact light flow in the system considering type of the parts. Authors performed measurement experiments to make clear the light flow with real-size model and miniature model of daylighting duct system. We discussed effect of type of the parts on efficiency of daylighting duct system.
基金Acknowledgements This study was supported by the National Natural Science Foundation of China （Grant Nos. 41275121 and 41575119） and the National Key Basic Research and Development Program of China （No. 2013CB228505） and Beijing Municipal Science ＆ Technology Commission （Grant No. Z161100000716004）.
文摘Industrial coal-fired boiler is an important air pollutant emission source in China. The chain-grate boiler is the most extensively used type of industrial coal-fired boiler. An electrical low-pressure impactor, and a Dekati？ Low Pressure Impactor were applied to determine mass and number size distributions of PM10 at the inlet and the outlet of the particulate emission control devices at six coalfired chain-grate boilers. The mass size distribution of PM10 generated from coal-fired chain-grate boilers generally displays a bimodal distribution that contains a submicron mode and a coarse mode. The PM in the submicron mode for burning with raw coal contributes to 33% ± 10 % of PM10 emissions, much higher than those for pulverized boilers. And the PM in the submicron mode for burning with briquette contributes up to 86 % of PM10 emissions. Multiclones and scrubbers are not efficient for controlling PM10 emission. Their average collection efficiencies for sub-micron particle and super-micron particle are 34% and 78%, respectively. Operating conditions of industrial steam boilers have influence on PM generation. Peak of the submicron mode during normal operation period is larger than the start-up period.
