Natural gas is currently playing an increasingly significant role in low carbon development,as it provides a credible pathway to meet rising energy demand while emitting fewer greenhouse gases than from using other fo...Natural gas is currently playing an increasingly significant role in low carbon development,as it provides a credible pathway to meet rising energy demand while emitting fewer greenhouse gases than from using other fossil fuels such as coal and oil.In this paper,a log linear trans-log production function model is established to investigate inter-fuel elasticity of substitution between coal,oil,natural gas and electricity in China,Japan and South Korea,respectively.In order to overcome the problem of multicollinearity,the ridge regression approach is therefore adopted to estimate the parameters of the function.Results show elasticity estimates of both coal-gas substitution and coal-electricity substitution to be positive over 1985-2012,suggesting that these two energy input pairs are substitutes at least to some extent.It also reveals that relatively higher substitution possibilities between coal and natural gas,and less opportunities to substitute coal with other fuels in China.In addition,the model results also suggest the elasticities of coal-gas substitution in China are much larger than that in Japan and South Korea,indicating there is higher possibilities of coal-gas substitution in China.展开更多
In this study,a novel irreversible cyclic model of a capacitive mixing blue heat engine mainly consisting of super capacitors,charging and discharging circuits,a heat source,as well as two water sources with given sal...In this study,a novel irreversible cyclic model of a capacitive mixing blue heat engine mainly consisting of super capacitors,charging and discharging circuits,a heat source,as well as two water sources with given salt concentrations is established for harvesting salinity gradient energy and waste heat.Additionally,the effects of the charging voltage and ratio of the minimum to maximum surface electric charge density on the thermodynamic efficiency and power output of the cycle are discussed.The maximum power output of the cycle is calculated.The optimized ranges of efficiency and power output as well as the temperatures of two isothermal processes are determined.It is established that during the isoelectric quantity process,there is not only an increase in thermal voltage owing to the temperature difference,but also an increase in concentration voltage owing to the salinity gradient.Consequently,the blue heat engine can obtain higher energy conversion efficiency than a conventional heat engine.When the temperature ratio of the heat source to the heat sink is 1.233,the maximum efficiency can reach approximately36%.The results obtained can promote the application of capacitive mixing technology in real life,reducing the consumption of fossil fuels.展开更多
文摘Natural gas is currently playing an increasingly significant role in low carbon development,as it provides a credible pathway to meet rising energy demand while emitting fewer greenhouse gases than from using other fossil fuels such as coal and oil.In this paper,a log linear trans-log production function model is established to investigate inter-fuel elasticity of substitution between coal,oil,natural gas and electricity in China,Japan and South Korea,respectively.In order to overcome the problem of multicollinearity,the ridge regression approach is therefore adopted to estimate the parameters of the function.Results show elasticity estimates of both coal-gas substitution and coal-electricity substitution to be positive over 1985-2012,suggesting that these two energy input pairs are substitutes at least to some extent.It also reveals that relatively higher substitution possibilities between coal and natural gas,and less opportunities to substitute coal with other fuels in China.In addition,the model results also suggest the elasticities of coal-gas substitution in China are much larger than that in Japan and South Korea,indicating there is higher possibilities of coal-gas substitution in China.
基金supported by the National Natural Science Foundation of China(Grant No.51876181)。
文摘In this study,a novel irreversible cyclic model of a capacitive mixing blue heat engine mainly consisting of super capacitors,charging and discharging circuits,a heat source,as well as two water sources with given salt concentrations is established for harvesting salinity gradient energy and waste heat.Additionally,the effects of the charging voltage and ratio of the minimum to maximum surface electric charge density on the thermodynamic efficiency and power output of the cycle are discussed.The maximum power output of the cycle is calculated.The optimized ranges of efficiency and power output as well as the temperatures of two isothermal processes are determined.It is established that during the isoelectric quantity process,there is not only an increase in thermal voltage owing to the temperature difference,but also an increase in concentration voltage owing to the salinity gradient.Consequently,the blue heat engine can obtain higher energy conversion efficiency than a conventional heat engine.When the temperature ratio of the heat source to the heat sink is 1.233,the maximum efficiency can reach approximately36%.The results obtained can promote the application of capacitive mixing technology in real life,reducing the consumption of fossil fuels.
