To address air pollution and offer a convenient and comfortable living environment,the Chinese government launched a smart city pilot(SCP)project in 2012,accompanied by a comprehensive set of environmental and energy-...To address air pollution and offer a convenient and comfortable living environment,the Chinese government launched a smart city pilot(SCP)project in 2012,accompanied by a comprehensive set of environmental and energy-related laws and regulations.Although academic interest in smart cities has surged,there remains a notable gap in empirical research exploring the economic,environmental,and energy effects of such initiatives.Taking 232 prefecture-level cities from 2003 to 2017 as research subjects,this study measures energy effi‐ciency by using energy consumption per unit of GDP and adopts a difference-in-differences(DID)analysis to investigate the impact of SCPs on energy efficiency.The empirical results indicate that SCPs improved energy efficiency by promoting urban technological innovation capabilities and green total factor productivity,and this effect was more pronounced in cities that were more dependent on traditional fossil fuel energy sources and had more developed fiscal and financial levels.Studying the impact of smart city construction on energy utilization efficiency in developing countries,such as China,is not only significantly enlightening for China’s green and low-carbon transition but also provides reference opinions for constructing smart cities and the path to enhancing energy efficiency in other developing countries.The findings provide valuable insights into the global development of smart cities,urban sustainability,and high-quality economic growth.展开更多
Bohai Rim region is an important economic development area and a large carbon emission area in China.It is of great significance to explore the total factor energy efficiency and its influencing factors for the low ca...Bohai Rim region is an important economic development area and a large carbon emission area in China.It is of great significance to explore the total factor energy efficiency and its influencing factors for the low carbon transformation and high-quality development of the Bohai Rim region.Based on the total factor energy efficiency framework,the DDF-DEA model was used to calculate the total factor energy efficiency,and the internal and external differences of the total factor energy efficiency were further analyzed.The internal and external influencing factors were determined by ML index method and classical endogenous growth theory,and then the Tobit panel model was used to empirically analyze the action mechanism of all influencing factors of total factor energy efficiency in the Bohai Rim region.The results show that the pure technical efficiency,scale efficiency and technological progress among the internal influencing factors contribute to the improvement of energy efficiency in the Bohai Rim region.Industrial structure,industrial internal structure and ownership structure inhibit the improvement of energy efficiency.Energy consumption structure and energy endowment also have a negative impact on energy efficiency.Therefore,measures such as promoting technological progress,adjusting economic structure and optimizing energy structure will effectively improve total factor energy efficiency in the Bohai Rim region.展开更多
Using 1995-2006 panel data for 210 cities,this article firstly measures total factor energy efficiency for Chinese cities with constant return to scale data envelopment analysis model,and then describes the features o...Using 1995-2006 panel data for 210 cities,this article firstly measures total factor energy efficiency for Chinese cities with constant return to scale data envelopment analysis model,and then describes the features of regional differences.The results show that the changing trend displays four "reversed U" shapes.A turning point of widening gap occurred among cities in 2000 and there was a certain convergence among four regions.Urban energy efficiency level is unstable.Cities with low efficiency and high energy input will be the focus of energy-saving and reducing emissions.According to Tobit model,resource endowment,temperature,industrial structure,technology level and variety of policy factors should be treated differently in different situations.展开更多
Mathematical modelling for power DC/DC converters is a historical problem accompanying DC/DC conversion technology since 1940’s. The traditional mathematical modelling is not available for complex structure converter...Mathematical modelling for power DC/DC converters is a historical problem accompanying DC/DC conversion technology since 1940’s. The traditional mathematical modelling is not available for complex structure converters since the differential equation order increases very high. We have to search other way to establish mathematical modelling for power DC/DC converters.We have theoretically defined a new concept-Energy Factor （EF） in this paper and researched the relations between EF and the mathematical modelling for power DC/DC converters. EF is a new concept in power DC/DC conversion technology, which thoroughly differs from the traditional concepts such as power factor （PF）, power transfer efficiency （η）, total harmonic distortion （THD） and ripple factor （RF）. EF and the subsequential EFV (and EFVD) can illustrate the system stability, reference response and interference recovery. This investigation is very helpful for system design and DC/DC converters characteristics foreseeing. Two DC/DC converters: Buck converter and Super-Lift Luo-Converter as the samples are analysed in this paper to demonstrate the applications of EF, EFV (and EFVD), PE, SE, VE （and VED）, time constant τ and damping time constant τd.展开更多
This study employed a difference-in-differences design to assess the effect of marketbased environmental regulation on green total factor energy efficiency(GTFEE)in a quasi-natural experiment that investigated China&#...This study employed a difference-in-differences design to assess the effect of marketbased environmental regulation on green total factor energy efficiency(GTFEE)in a quasi-natural experiment that investigated China's carbon emissions trading scheme(ETS).The empirical results show that ETS had a positive effect on GTFEE.A series of robustness tests revealed that the results were robust.Potential mechanisms through which ETS can improve GTFEE include the promotion of technological innovation and the upgrading of industrial structure.The positive effects varied in different cities and diferent regions-the result was pronounced in eastern China and developed cities,but it was insignificant in central and western areas and developing cities.This study confirms the satisfactory performance of China's ETS in improving GTFEE,and this is relevant for other emerging countries.展开更多
文摘To address air pollution and offer a convenient and comfortable living environment,the Chinese government launched a smart city pilot(SCP)project in 2012,accompanied by a comprehensive set of environmental and energy-related laws and regulations.Although academic interest in smart cities has surged,there remains a notable gap in empirical research exploring the economic,environmental,and energy effects of such initiatives.Taking 232 prefecture-level cities from 2003 to 2017 as research subjects,this study measures energy effi‐ciency by using energy consumption per unit of GDP and adopts a difference-in-differences(DID)analysis to investigate the impact of SCPs on energy efficiency.The empirical results indicate that SCPs improved energy efficiency by promoting urban technological innovation capabilities and green total factor productivity,and this effect was more pronounced in cities that were more dependent on traditional fossil fuel energy sources and had more developed fiscal and financial levels.Studying the impact of smart city construction on energy utilization efficiency in developing countries,such as China,is not only significantly enlightening for China’s green and low-carbon transition but also provides reference opinions for constructing smart cities and the path to enhancing energy efficiency in other developing countries.The findings provide valuable insights into the global development of smart cities,urban sustainability,and high-quality economic growth.
基金supported by the National Natural Science Foundation of China under Grant 71804089the Humanities and Social Sciences Youth Foundation of Ministry of Education of China under Grants 18YJCZH034 and 19YJC790128+3 种基金the Jiangsu Postdoctoral Research Foundation underGrant 2018K195C,the Natural Science Foundation of Shandong Province in China under Grant ZR2020QG054the Graduate Education Quality Improvement Project of Shandong Province,China under Grants SDYKC19180 and SDYAL19180The project number of“The quality course in Financial Statistics”is SDYKC19180The project number of“Financial Literacy Oriented Case Library of Derivative Financial Instruments Teaching”is SDYAL19180.
文摘Bohai Rim region is an important economic development area and a large carbon emission area in China.It is of great significance to explore the total factor energy efficiency and its influencing factors for the low carbon transformation and high-quality development of the Bohai Rim region.Based on the total factor energy efficiency framework,the DDF-DEA model was used to calculate the total factor energy efficiency,and the internal and external differences of the total factor energy efficiency were further analyzed.The internal and external influencing factors were determined by ML index method and classical endogenous growth theory,and then the Tobit panel model was used to empirically analyze the action mechanism of all influencing factors of total factor energy efficiency in the Bohai Rim region.The results show that the pure technical efficiency,scale efficiency and technological progress among the internal influencing factors contribute to the improvement of energy efficiency in the Bohai Rim region.Industrial structure,industrial internal structure and ownership structure inhibit the improvement of energy efficiency.Energy consumption structure and energy endowment also have a negative impact on energy efficiency.Therefore,measures such as promoting technological progress,adjusting economic structure and optimizing energy structure will effectively improve total factor energy efficiency in the Bohai Rim region.
基金provided by the major issues of philosophy and social science research projects of Chinese Ministry of Education(Project no.:09JZD0019)
文摘Using 1995-2006 panel data for 210 cities,this article firstly measures total factor energy efficiency for Chinese cities with constant return to scale data envelopment analysis model,and then describes the features of regional differences.The results show that the changing trend displays four "reversed U" shapes.A turning point of widening gap occurred among cities in 2000 and there was a certain convergence among four regions.Urban energy efficiency level is unstable.Cities with low efficiency and high energy input will be the focus of energy-saving and reducing emissions.According to Tobit model,resource endowment,temperature,industrial structure,technology level and variety of policy factors should be treated differently in different situations.
文摘Mathematical modelling for power DC/DC converters is a historical problem accompanying DC/DC conversion technology since 1940’s. The traditional mathematical modelling is not available for complex structure converters since the differential equation order increases very high. We have to search other way to establish mathematical modelling for power DC/DC converters.We have theoretically defined a new concept-Energy Factor （EF） in this paper and researched the relations between EF and the mathematical modelling for power DC/DC converters. EF is a new concept in power DC/DC conversion technology, which thoroughly differs from the traditional concepts such as power factor （PF）, power transfer efficiency （η）, total harmonic distortion （THD） and ripple factor （RF）. EF and the subsequential EFV (and EFVD) can illustrate the system stability, reference response and interference recovery. This investigation is very helpful for system design and DC/DC converters characteristics foreseeing. Two DC/DC converters: Buck converter and Super-Lift Luo-Converter as the samples are analysed in this paper to demonstrate the applications of EF, EFV (and EFVD), PE, SE, VE （and VED）, time constant τ and damping time constant τd.
基金the Fundamental Research Funds for the Central Universities in Donghua University and Shanghai Soft Science Research Project(No.23692120100).
文摘This study employed a difference-in-differences design to assess the effect of marketbased environmental regulation on green total factor energy efficiency(GTFEE)in a quasi-natural experiment that investigated China's carbon emissions trading scheme(ETS).The empirical results show that ETS had a positive effect on GTFEE.A series of robustness tests revealed that the results were robust.Potential mechanisms through which ETS can improve GTFEE include the promotion of technological innovation and the upgrading of industrial structure.The positive effects varied in different cities and diferent regions-the result was pronounced in eastern China and developed cities,but it was insignificant in central and western areas and developing cities.This study confirms the satisfactory performance of China's ETS in improving GTFEE,and this is relevant for other emerging countries.
