Remarkable achievements have been made in China＇s agricultural development since the late 1970s. Nevertheless, deep-rooted problems are arising from inefficient farming practices. From mid- and long-term perspectives...Remarkable achievements have been made in China＇s agricultural development since the late 1970s. Nevertheless, deep-rooted problems are arising from inefficient farming practices. From mid- and long-term perspectives, migration of China＇s agricultural labor will slow and large-scale operation of farmland will accelerate. Although grain supply and demand have maintained a tight balance, new potentials still exist in improving grain production. Under the pressures of resource and environmental constraints, advancing the green and efficient transition of agriculture will become a new trend in China＇s agricultural development. In this context, the treatment of agricultural pollution, supply-side structural reform and innovation of agricultural subsidy policy are of strategic significance to the transition and upgrade of China＇s agriculture.展开更多
Developing efficient approaches for lignin upgrading is of interest for the industrial production of chemicals and fuels from renewable biomass.Electrocatalytic lignin upgrading powered by renewable electricity operat...Developing efficient approaches for lignin upgrading is of interest for the industrial production of chemicals and fuels from renewable biomass.Electrocatalytic lignin upgrading powered by renewable electricity operating under gentle conditions(at or near ambient pressures and temperatures)enables a decentralized production of chemicals and fuels.Herein,we will cover the structures of lignin and review the recent advances in the electrocatalytic lignin upgrade,the electrocatalytic depolymerization of lignin,and the electrocatalytic upgrading of lignin monomers to value-added chemicals and fuels.Finally,we provide insights into the main challenges and future perspectives of this field.展开更多
Digital technology is an instrument and vehicle for digital empowerment and the development of the digital economy.Digital applications in the service sector have spawned new business modes over recent years such as i...Digital technology is an instrument and vehicle for digital empowerment and the development of the digital economy.Digital applications in the service sector have spawned new business modes over recent years such as industrial internet platforms,new retail and online education,which have contributed to China s service sector growth and transition.With the help of digital technology,the service sector has maintained rapid growth,improved in terms of structure,quality and efficiency,increased public welfare,and enhanced indigenous innovation.In light of inadequate and uneven progress of digitalization and insufficient factor support and government incentives,we suggest that the government further advance digitalization development across the board,bolster factor support,and enhance policymaking.展开更多
Over the past seven decades since the founding of the People's Republic of China in 1949,China's industrial structure has experienced transformations in various stages,which is consistent with the general patt...Over the past seven decades since the founding of the People's Republic of China in 1949,China's industrial structure has experienced transformations in various stages,which is consistent with the general pattern of industrialization and China's domestic and international situations.These changes also have to do with China's reforms in building the socialist market economic system.China's seven-decade industrial structural transformation offers valuable experiences:In promoting its industrial development,China has persistently carried out economic reforms,kept pace with changing factor and demand structures,invested in technology importation and innovation,leveraged global resources and markets,and formulated development policies in line with specific industrial development stages.Despite industrial structural problems,China has set the stage for innovation-driven development,further opening up,and balanced regional development.China's industrial structure will keep evolving amid its transition toward a competitive industrial nation.展开更多
With the establishment of labor market of China, market is playing a more and mare important role in allocation of human resources. However, with the transition of economy in China and industrial upgrading in recent y...With the establishment of labor market of China, market is playing a more and mare important role in allocation of human resources. However, with the transition of economy in China and industrial upgrading in recent years, many labor problems have occurred which do harm to the sustainable development of local economy. The paper researches on the labor market issues of China from the perspective of local labor market regulation. Firstly, it reviews the theories of local labor market regulation. And then the main components of local labor market regulation of China are identified and the evaluation index system is established. The results of analysis of the calculated output show that （1） the local labor market regulation of China has an obvious character of gradient distribution geographically and decreases gradually from east to west; （2） of all the regulations, the regulation of the development of human capital has the most significant impact on local economy currently which is followed by the regulation of labor relation and the regulation of market participation. As to the regulation of social security, it has no Significant impact on the development of local economy.展开更多
This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this con...This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this converter a front-end power factor corrected boost stage integrates with a cascaded dc-to-dc bridge HF converter. The front-end boost converter operates in discontinuous current mode and ensures natural power factor correction with very simple control. The auxiliary circuit of this topology deals with very small power and is placed out of the main power path. As a result, the auxiliary circuit components have smaller power rating as opposed to main converter components. Also, output rectifier voltage is clamped to output voltage due to capacitive output filter. Identification and analyses of different operating modes of this converter are presented. Based on these analyses design example of a 50 kHz, 48 V, 1 kW ac-to-dc converter is presented. PSPICE simulation results of the designed converter are presented and explained to verify the performance of this converter.展开更多
With the implementation of the ＂Development of Western China＂ strategy, this region has become the fastest growing economic area in China. However, rapid economic growth has resulted in a substantial increase in car...With the implementation of the ＂Development of Western China＂ strategy, this region has become the fastest growing economic area in China. However, rapid economic growth has resulted in a substantial increase in carbon emissions and affected energy reduction goals. In order to effectively control the rapid increase in carbon emissions across western China, we need a comprehensively analyze the main factors causing these increases. Here, we analyze the relationship between economic development patterns and carbon emissions. The findings suggest that consumption upgrades and industrial transformation have a positive correlation with carbon emissions in this region. We then conducted an econometric FGLS analysis on the relationship and its transmission mechanism between economic growth and CO2 emissions with cross-province panel data from 1991 to 2009. A positive correlation was found, and the relationship is more significant after the implementation of the western development strategy. The influence coefficient of change in primary, secondary and tertiary industries is 16.4. The influence coefficient of increased share of heavy industry and extractive industry in the secondary industry is 14.3, and the influence coefficients of per-capita living expenditure and per capita traffic expenditure are 5.6 and 6.5. Traditional population size and income scale have a weak impact on carbon emissions, and the influence coefficients of population size and income scale are only 0.73 and 0.86. GDP increases have a second major impact on the carbon emissions. Energy intensity has a negative relationship with carbon emissions and urbanization level has a positive relationship （coefficients are -8.2 and 4.65）.展开更多
文摘Remarkable achievements have been made in China＇s agricultural development since the late 1970s. Nevertheless, deep-rooted problems are arising from inefficient farming practices. From mid- and long-term perspectives, migration of China＇s agricultural labor will slow and large-scale operation of farmland will accelerate. Although grain supply and demand have maintained a tight balance, new potentials still exist in improving grain production. Under the pressures of resource and environmental constraints, advancing the green and efficient transition of agriculture will become a new trend in China＇s agricultural development. In this context, the treatment of agricultural pollution, supply-side structural reform and innovation of agricultural subsidy policy are of strategic significance to the transition and upgrade of China＇s agriculture.
文摘Developing efficient approaches for lignin upgrading is of interest for the industrial production of chemicals and fuels from renewable biomass.Electrocatalytic lignin upgrading powered by renewable electricity operating under gentle conditions(at or near ambient pressures and temperatures)enables a decentralized production of chemicals and fuels.Herein,we will cover the structures of lignin and review the recent advances in the electrocatalytic lignin upgrade,the electrocatalytic depolymerization of lignin,and the electrocatalytic upgrading of lignin monomers to value-added chemicals and fuels.Finally,we provide insights into the main challenges and future perspectives of this field.
文摘Digital technology is an instrument and vehicle for digital empowerment and the development of the digital economy.Digital applications in the service sector have spawned new business modes over recent years such as industrial internet platforms,new retail and online education,which have contributed to China s service sector growth and transition.With the help of digital technology,the service sector has maintained rapid growth,improved in terms of structure,quality and efficiency,increased public welfare,and enhanced indigenous innovation.In light of inadequate and uneven progress of digitalization and insufficient factor support and government incentives,we suggest that the government further advance digitalization development across the board,bolster factor support,and enhance policymaking.
文摘Over the past seven decades since the founding of the People's Republic of China in 1949,China's industrial structure has experienced transformations in various stages,which is consistent with the general pattern of industrialization and China's domestic and international situations.These changes also have to do with China's reforms in building the socialist market economic system.China's seven-decade industrial structural transformation offers valuable experiences:In promoting its industrial development,China has persistently carried out economic reforms,kept pace with changing factor and demand structures,invested in technology importation and innovation,leveraged global resources and markets,and formulated development policies in line with specific industrial development stages.Despite industrial structural problems,China has set the stage for innovation-driven development,further opening up,and balanced regional development.China's industrial structure will keep evolving amid its transition toward a competitive industrial nation.
基金supported by Knowledge Innovation Program of The Chinese Academy of Sciences (Grant No. O7Q70100AD).
文摘With the establishment of labor market of China, market is playing a more and mare important role in allocation of human resources. However, with the transition of economy in China and industrial upgrading in recent years, many labor problems have occurred which do harm to the sustainable development of local economy. The paper researches on the labor market issues of China from the perspective of local labor market regulation. Firstly, it reviews the theories of local labor market regulation. And then the main components of local labor market regulation of China are identified and the evaluation index system is established. The results of analysis of the calculated output show that （1） the local labor market regulation of China has an obvious character of gradient distribution geographically and decreases gradually from east to west; （2） of all the regulations, the regulation of the development of human capital has the most significant impact on local economy currently which is followed by the regulation of labor relation and the regulation of market participation. As to the regulation of social security, it has no Significant impact on the development of local economy.
文摘This paper presents a new ZVT （zero-voltage transition） single-stage ac-to-dc converter using PWM （pulse width modulation） and HF （high frequency） transformer isolation with capacitive output filter. In this converter a front-end power factor corrected boost stage integrates with a cascaded dc-to-dc bridge HF converter. The front-end boost converter operates in discontinuous current mode and ensures natural power factor correction with very simple control. The auxiliary circuit of this topology deals with very small power and is placed out of the main power path. As a result, the auxiliary circuit components have smaller power rating as opposed to main converter components. Also, output rectifier voltage is clamped to output voltage due to capacitive output filter. Identification and analyses of different operating modes of this converter are presented. Based on these analyses design example of a 50 kHz, 48 V, 1 kW ac-to-dc converter is presented. PSPICE simulation results of the designed converter are presented and explained to verify the performance of this converter.
基金Humanity and Social Science Youth foundation of Ministry of Education of China (12YJC790082)National Social Science Fund Key Project (11AJL007)
文摘With the implementation of the ＂Development of Western China＂ strategy, this region has become the fastest growing economic area in China. However, rapid economic growth has resulted in a substantial increase in carbon emissions and affected energy reduction goals. In order to effectively control the rapid increase in carbon emissions across western China, we need a comprehensively analyze the main factors causing these increases. Here, we analyze the relationship between economic development patterns and carbon emissions. The findings suggest that consumption upgrades and industrial transformation have a positive correlation with carbon emissions in this region. We then conducted an econometric FGLS analysis on the relationship and its transmission mechanism between economic growth and CO2 emissions with cross-province panel data from 1991 to 2009. A positive correlation was found, and the relationship is more significant after the implementation of the western development strategy. The influence coefficient of change in primary, secondary and tertiary industries is 16.4. The influence coefficient of increased share of heavy industry and extractive industry in the secondary industry is 14.3, and the influence coefficients of per-capita living expenditure and per capita traffic expenditure are 5.6 and 6.5. Traditional population size and income scale have a weak impact on carbon emissions, and the influence coefficients of population size and income scale are only 0.73 and 0.86. GDP increases have a second major impact on the carbon emissions. Energy intensity has a negative relationship with carbon emissions and urbanization level has a positive relationship （coefficients are -8.2 and 4.65）.
