The year 2024 marks the tenth anniversary of China’s comprehensive implementation of the new energy security strategy,“Four Revolutions,One Cooperation.”Over the past decade,China has experienced a series of signif...The year 2024 marks the tenth anniversary of China’s comprehensive implementation of the new energy security strategy,“Four Revolutions,One Cooperation.”Over the past decade,China has experienced a series of significant changes in its energy sector,promoting comprehensive reforms in energy consumption patterns and consistently pursuing a cleaner,low-carbon energy structure.The country has accelerated the development of a diverse and clean energy supply system,creating a multifaceted supply network driven by coal,oil,gas,nuclear,and renewable energy sources,and continuously enhancing its energy supply capacity.By leveraging technological innovation as the primary driving force,China has thoroughly deepened energy system reforms to unleash market vitality and has strengthened international cooperation in the energy sector across all dimensions.The construction of a strong energy nation has further advanced,with significantly enhanced security assurance capabilities,effectively supporting and serving the healthy development of the economy and society.To accelerate the development of a new energy system,relevant national departments have introduced a series of industry policies and reform proposals in the energy sector.These initiatives aim to strongly support high-quality energy development by strengthening energy supply security,promoting a green and low-carbon energy transition,enhancing energy utilization efficiency,and improving energy market mechanisms and regulation.展开更多
With the background of offshore wind energy projects, this paper studies aerodynamic performance and geometric characteristics of large capacity wind turbine rotors （1 to 10 MW）, and the main characteristic paramete...With the background of offshore wind energy projects, this paper studies aerodynamic performance and geometric characteristics of large capacity wind turbine rotors （1 to 10 MW）, and the main characteristic parameters such as the rated wind speed, blade tip speed, and rotor solidity. We show that the essential criterion of a high- performance wind turbine is a highest possible annual usable energy pattern factor and a smallest possible dimension, capturing the maximum wind energy and producing the maximum annual power. The influence of the above-mentioned three parameters on the pattern factor and rotor geometry of wind turbine operated in China＇s offshore meteoro- logical environment is investigated. The variation patterns of aerodynamic and geometric parameters are obtained, analyzed, and compared with each other. The present method for aerodynamic analysis and its results can form a basis for evaluating aerodynamic performance of large-scale offshore wind turbine rotors.展开更多
Studies of the effects induced on the electron band structure after Na deposition, and subsequent heating, on a C-face 2 MLs graphene sample are reported. Na deposition shifts the Dirac point downwards from the Fermi ...Studies of the effects induced on the electron band structure after Na deposition, and subsequent heating, on a C-face 2 MLs graphene sample are reported. Na deposition shifts the Dirac point downwards from the Fermi level by about 0.5 eV due to electron doping. After heating at temperatures from around 120℃ to 300℃,thep-band appears considerably broadened. Collected Si 2p and Na 2p spectra then indicate Na intercalation in between the graphene layers and at the graphene SiC interface. The broadening is therefore interpreted to arise from the presence of two slightly shifted, but not clearly resolved,p-bands. Constant energy photoelectron distribution patterns, E(kx,ky);s, extracted from the clean 2MLs graphene C-face sample look very similar to earlier calculated distribution patterns for monolayer, but not Bernal stacked bilayer, graphene. After Na deposition the patterns extracted at energies below the Dirac point appear very similar so the doping had no pronounced effect on the shape or intensity distribution. At energies above the Dirac point the extracted angular distribution patterns show the flipped, “mirrored”, intensity distribution predicted for monolayer graphene at these energies. An additional weaker outer band is also discernable at energies above the Dirac point, which presumably is induced by the deposited Na.展开更多
Ambient temperature is an important factor affecting metabolic processes in animals,and its effect on energy metabolism is becoming more evident.Yet,integrative analysis of energy metabolism in finishing pigs at diffe...Ambient temperature is an important factor affecting metabolic processes in animals,and its effect on energy metabolism is becoming more evident.Yet,integrative analysis of energy metabolism in finishing pigs at different combinations of ambient temperature,energy density and energy sources,still remain underexplored.In order to determine the special characteristics of energy metabolism of finishing pigs in low-temperature environment,the effects of different combinations of ambient temperature,energy density,and energy source on underlying mechanisms were elucidated by assessing energy metabolism using integrative indirect calorimetry and non-targeted plasma metabolomics analyses.Thirty-two finishing pigs(Duroc×Large White×Landrace)with similar body weight of 85.44±2.04 kg were allotted in a 2×2×2 factorial arrangement(8 treatment groups,4 replicates per group,1 pig per replicate),which included two ambient temperatures(low temperature[10℃]and normal temperature[20℃]),two energy densities(normal energy density[NE,14.02 MJ/kg]and high energe density[HE,15.14 MJ/kg]),and two energy sources(low-oil source and high-oil source).The experiment period lasted 11 days.Increasing the energy density of the diet by adding oil changed the energy source in a low-temperature environment,improved crude fat digestibility(P<0.001),and reduced the feed/gain ratio of pigs(P=0.004),with a tendency for higher average daily gain(P=0.098),which would increase energy utilization.Adding oil to the diet altered energy sources at low temperature,reducing carbon dioxide emission by 3.10%,increasing energy retention and fat oxidation(P<0.05).Further,optimizing energy sources by adding oil significantly improved serum glucose(GLU)content(P<0.001)and reduced urea nitrogen(UN)content at normal temperature(P<0.001),with the same trend observed at low temperature.The metabolites in the eight groups were mainly enriched in the sphingolipid signaling pathway,insulin resistance,and glycerophospholipid metabolism(P<0.05).Energy metabolism in finishing pigs was not only affected by ambient temperature and energy density,but also by energy source,leading to variations in metabolic pathways for different energy substances.Increasing the dietary energy density by increasing oil supplementation at low temperature is an effective way to improve the growth performance of finishing pigs while reducing pollutant emissions.The study provides a new solution for optimizing energy nutrition for finishing pigs in low-temperature environment.展开更多
The aim of this research was to investigate the energy use and costs of pomegranate production in Behshahr city(Mazandaran province)of Iran.The required data were gathered by questionnaire and face to face interviews ...The aim of this research was to investigate the energy use and costs of pomegranate production in Behshahr city(Mazandaran province)of Iran.The required data were gathered by questionnaire and face to face interviews with 83 pomegranate producers.Cobb-Douglas model and sensitivity analysis were employed for energy flows modeling of the production system.The total energy inputs and energy output of production were determined to be 11195.06 and 13276.56 MJ ha1,and two inputs of diesel fuel and chemical fertilizers with the shares of 45.81 and 23.47%,were the highest energy consumers for pomegranate production.Energy use efficiency,energy productivity and net energy were 1.18,2081.50 MJ ha1 and 0.62 kg MJ1,respectively.The results of Cobb-Douglas model showed that the effect of the energy inputs including human labor,biocides,chemical fertilizers,farmyard manure,electricity and water for irrigation on pomegranates yield were positive,while the effects of diesel fuel and agricultural machinery were negative on the pomegranate yield.The sensitivity analysis results of energy inputs showed that with the increase of one MJ in the energy input of water for irrigation and chemical fertilizers,the yield was increased to 3.12 and 1.42 kg,respectively.Also with the increase of one MJ in diesel fuel and agricultural machinery inputs,the yield was decreased to 0.67 and 0.47 kg,respectively.Diesel fuel as the most used energy input in the production accounted for 0.85%of variable costs and the benefit to cost ratio was determined to be 5.57.展开更多
The“average occupant”methodology is widely used in energy consumption simulations of residential buildings;however,it fails to consider the differences in energy use behavior among family members.Based on a field su...The“average occupant”methodology is widely used in energy consumption simulations of residential buildings;however,it fails to consider the differences in energy use behavior among family members.Based on a field survey on the Central Shaanxi Plain,to identify the energy use behavior patterns of typical families,a stochastic energy use behavior model considering differences in energy use behavior among family members was proposed,to improve the accuracy of energy consumption simulations of residential buildings.The results indicated that the surveyed rural families could be classified into the following four types depending on specific energy use behavior patterns:families of one elderly couple,families of one middle-aged couple,families of one elderly couple and one child,and families of one couple and one child.Moreover,on typical summer days,the results of daily building energy consumption simulation obtained by the“average occupant”methodology were 25.39%and 28%lower than the simulation results obtained by the model proposed in this study for families of one elderly couple and families of one middle-aged couple,and 13.05%and 23.05%higher for families of one elderly couple and one child,and families of one couple and one child.On typical winter days,for the four types of families,the results of daily building energy consumption simulation obtained by the“average occupant”methodology were 21.69%,10.84%,1.21%,and 8.39%lower than the simulation results obtained by the model proposed in this study,respectively.展开更多
文摘The year 2024 marks the tenth anniversary of China’s comprehensive implementation of the new energy security strategy,“Four Revolutions,One Cooperation.”Over the past decade,China has experienced a series of significant changes in its energy sector,promoting comprehensive reforms in energy consumption patterns and consistently pursuing a cleaner,low-carbon energy structure.The country has accelerated the development of a diverse and clean energy supply system,creating a multifaceted supply network driven by coal,oil,gas,nuclear,and renewable energy sources,and continuously enhancing its energy supply capacity.By leveraging technological innovation as the primary driving force,China has thoroughly deepened energy system reforms to unleash market vitality and has strengthened international cooperation in the energy sector across all dimensions.The construction of a strong energy nation has further advanced,with significantly enhanced security assurance capabilities,effectively supporting and serving the healthy development of the economy and society.To accelerate the development of a new energy system,relevant national departments have introduced a series of industry policies and reform proposals in the energy sector.These initiatives aim to strongly support high-quality energy development by strengthening energy supply security,promoting a green and low-carbon energy transition,enhancing energy utilization efficiency,and improving energy market mechanisms and regulation.
基金supported by the National Basic Research Program of China (973 Program) (No. 2007CB714605)
文摘With the background of offshore wind energy projects, this paper studies aerodynamic performance and geometric characteristics of large capacity wind turbine rotors （1 to 10 MW）, and the main characteristic parameters such as the rated wind speed, blade tip speed, and rotor solidity. We show that the essential criterion of a high- performance wind turbine is a highest possible annual usable energy pattern factor and a smallest possible dimension, capturing the maximum wind energy and producing the maximum annual power. The influence of the above-mentioned three parameters on the pattern factor and rotor geometry of wind turbine operated in China＇s offshore meteoro- logical environment is investigated. The variation patterns of aerodynamic and geometric parameters are obtained, analyzed, and compared with each other. The present method for aerodynamic analysis and its results can form a basis for evaluating aerodynamic performance of large-scale offshore wind turbine rotors.
基金support from the European Science Foundation,within the EuroGRA-PHENE(EPIGRAT)programthe Swedish Research Council(#621-2011-4252 and Linnaeus Grant).
文摘Studies of the effects induced on the electron band structure after Na deposition, and subsequent heating, on a C-face 2 MLs graphene sample are reported. Na deposition shifts the Dirac point downwards from the Fermi level by about 0.5 eV due to electron doping. After heating at temperatures from around 120℃ to 300℃,thep-band appears considerably broadened. Collected Si 2p and Na 2p spectra then indicate Na intercalation in between the graphene layers and at the graphene SiC interface. The broadening is therefore interpreted to arise from the presence of two slightly shifted, but not clearly resolved,p-bands. Constant energy photoelectron distribution patterns, E(kx,ky);s, extracted from the clean 2MLs graphene C-face sample look very similar to earlier calculated distribution patterns for monolayer, but not Bernal stacked bilayer, graphene. After Na deposition the patterns extracted at energies below the Dirac point appear very similar so the doping had no pronounced effect on the shape or intensity distribution. At energies above the Dirac point the extracted angular distribution patterns show the flipped, “mirrored”, intensity distribution predicted for monolayer graphene at these energies. An additional weaker outer band is also discernable at energies above the Dirac point, which presumably is induced by the deposited Na.
基金supported by the National Natural Science Foundation of China(U21A20254)the Jilin Provincial Scientific and Technological Development Program(20230202078NC).
文摘Ambient temperature is an important factor affecting metabolic processes in animals,and its effect on energy metabolism is becoming more evident.Yet,integrative analysis of energy metabolism in finishing pigs at different combinations of ambient temperature,energy density and energy sources,still remain underexplored.In order to determine the special characteristics of energy metabolism of finishing pigs in low-temperature environment,the effects of different combinations of ambient temperature,energy density,and energy source on underlying mechanisms were elucidated by assessing energy metabolism using integrative indirect calorimetry and non-targeted plasma metabolomics analyses.Thirty-two finishing pigs(Duroc×Large White×Landrace)with similar body weight of 85.44±2.04 kg were allotted in a 2×2×2 factorial arrangement(8 treatment groups,4 replicates per group,1 pig per replicate),which included two ambient temperatures(low temperature[10℃]and normal temperature[20℃]),two energy densities(normal energy density[NE,14.02 MJ/kg]and high energe density[HE,15.14 MJ/kg]),and two energy sources(low-oil source and high-oil source).The experiment period lasted 11 days.Increasing the energy density of the diet by adding oil changed the energy source in a low-temperature environment,improved crude fat digestibility(P<0.001),and reduced the feed/gain ratio of pigs(P=0.004),with a tendency for higher average daily gain(P=0.098),which would increase energy utilization.Adding oil to the diet altered energy sources at low temperature,reducing carbon dioxide emission by 3.10%,increasing energy retention and fat oxidation(P<0.05).Further,optimizing energy sources by adding oil significantly improved serum glucose(GLU)content(P<0.001)and reduced urea nitrogen(UN)content at normal temperature(P<0.001),with the same trend observed at low temperature.The metabolites in the eight groups were mainly enriched in the sphingolipid signaling pathway,insulin resistance,and glycerophospholipid metabolism(P<0.05).Energy metabolism in finishing pigs was not only affected by ambient temperature and energy density,but also by energy source,leading to variations in metabolic pathways for different energy substances.Increasing the dietary energy density by increasing oil supplementation at low temperature is an effective way to improve the growth performance of finishing pigs while reducing pollutant emissions.The study provides a new solution for optimizing energy nutrition for finishing pigs in low-temperature environment.
文摘The aim of this research was to investigate the energy use and costs of pomegranate production in Behshahr city(Mazandaran province)of Iran.The required data were gathered by questionnaire and face to face interviews with 83 pomegranate producers.Cobb-Douglas model and sensitivity analysis were employed for energy flows modeling of the production system.The total energy inputs and energy output of production were determined to be 11195.06 and 13276.56 MJ ha1,and two inputs of diesel fuel and chemical fertilizers with the shares of 45.81 and 23.47%,were the highest energy consumers for pomegranate production.Energy use efficiency,energy productivity and net energy were 1.18,2081.50 MJ ha1 and 0.62 kg MJ1,respectively.The results of Cobb-Douglas model showed that the effect of the energy inputs including human labor,biocides,chemical fertilizers,farmyard manure,electricity and water for irrigation on pomegranates yield were positive,while the effects of diesel fuel and agricultural machinery were negative on the pomegranate yield.The sensitivity analysis results of energy inputs showed that with the increase of one MJ in the energy input of water for irrigation and chemical fertilizers,the yield was increased to 3.12 and 1.42 kg,respectively.Also with the increase of one MJ in diesel fuel and agricultural machinery inputs,the yield was decreased to 0.67 and 0.47 kg,respectively.Diesel fuel as the most used energy input in the production accounted for 0.85%of variable costs and the benefit to cost ratio was determined to be 5.57.
基金funded by the National Natural Science Foundation of China(52378109)Shaanxi Provincial Department of Science and Technology(2023KJXX-043).
文摘The“average occupant”methodology is widely used in energy consumption simulations of residential buildings;however,it fails to consider the differences in energy use behavior among family members.Based on a field survey on the Central Shaanxi Plain,to identify the energy use behavior patterns of typical families,a stochastic energy use behavior model considering differences in energy use behavior among family members was proposed,to improve the accuracy of energy consumption simulations of residential buildings.The results indicated that the surveyed rural families could be classified into the following four types depending on specific energy use behavior patterns:families of one elderly couple,families of one middle-aged couple,families of one elderly couple and one child,and families of one couple and one child.Moreover,on typical summer days,the results of daily building energy consumption simulation obtained by the“average occupant”methodology were 25.39%and 28%lower than the simulation results obtained by the model proposed in this study for families of one elderly couple and families of one middle-aged couple,and 13.05%and 23.05%higher for families of one elderly couple and one child,and families of one couple and one child.On typical winter days,for the four types of families,the results of daily building energy consumption simulation obtained by the“average occupant”methodology were 21.69%,10.84%,1.21%,and 8.39%lower than the simulation results obtained by the model proposed in this study,respectively.
