The oxygen evolution reaction (OER) dominates the efficiency of electrocatalytic water splitting owing to its sluggish kinetics.Perovskite oxides (ABO_(3)) have emerged as promising candidates to accelerate the OER pr...The oxygen evolution reaction (OER) dominates the efficiency of electrocatalytic water splitting owing to its sluggish kinetics.Perovskite oxides (ABO_(3)) have emerged as promising candidates to accelerate the OER process owing to their high intrinsic activities and tailorable properties.Fe ions in perovskite oxides have been proved to be a highly catalytic element for OER,while some Fe-based perovskites such as SrTi_(0.8)Fe_(0.2)O_(3-δ)(STF) and La_(0.66)Ti_(0.8)Fe_(0.2)O_(3-δ)(LTF) exhibit inferior OER activity.Yet the essential reason is still unclear and the effective method to promote the activity of such perovskite is also lacking.Herein,an in-situ exsolution strategy was proposed to boost the OER by migrating Fe from the bulk to the surface.Significantly enhanced OER activity was achieved on STF and LTF perovskites with surfacedecorated oxygen vacancies and Fe nanoparticles.In addition,theoretical calculation confirmed that the oxygen vacancies and Fe nanoparticle on surface could lower the overpotential of OER by facilitating the adsorption of OH^(-).From this study,migration of the active elements in perovskite is found to be an effective strategy to increase the quantity and activity of active sites,providing new insights and understanding for designing efficient OER catalysts.展开更多
Developing high active and stable bifunctional electrocatalysts towards oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is essential for the development of rechargeable Zn-air batteries.Herein,a facile...Developing high active and stable bifunctional electrocatalysts towards oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is essential for the development of rechargeable Zn-air batteries.Herein,a facile strategy to synthesize the porous carbon layers wrapped CoFe alloy(C/CoFe)through the pyrolysis of a homogeneous mixture containing Co,Fe ions and N-doped carbon quantum dots(Ndoped CQDs)was reported.The prepared carbon layers with multi-level pore structures provides more active sites and optimizes the homogeneity of the electron and mass transport.In addition,the carbon layers,which is doped by Co/Fe/N atoms,is responsible for high ORR activity,while the CoFe alloy plays a vital role in OER performance.The as-synthesized catalyst exhibits an excellent bifunctionality for electrochemical oxygen reactions,which is comparable to the commercial Pt/C and IrO2 benchmarks.Owing to the carbon layers protects CoFe alloy nanoparticles from the harsh environment,the rechargeable Znair battery with the C/CoFe catalyst delivers excellent stability during 20,000 charging-discharging cycles.展开更多
Decarbonization of the power sector in China is an essential aspect of the energy transition process to achieve carbon neutrality.The power sector accounts for approximately 40%of China’s total CO_(2) emissions.Accor...Decarbonization of the power sector in China is an essential aspect of the energy transition process to achieve carbon neutrality.The power sector accounts for approximately 40%of China’s total CO_(2) emissions.Accordingly,collaborative optimization in power generation expansion planning(GEP)simultaneously considering economic,environmental,and technological concerns as carbon emissions is necessary.This paper proposes a collaborative mixedinteger linear programming optimization approach for GEP.This minimizes the power system’s operating cost to resolve emission concerns considering energy development strategies,flexible generation,and resource limitations constraints.This research further analyzes the advantages and disadvantages of current GEP techniques.Results show that the main determinants of new investment decisions are carbon emissions,reserve margins,resource availability,fuel consumption,and fuel price.The proposed optimization method is simulated and validated based on China’s power system data.Finally,this study provides policy recommendations on the flexible management of traditional power sources,the market-oriented mechanism of new energy sources,and the integration of new technology to support the attainment of carbon-neutral targets in the current energy transition process.展开更多
The energy sector has an essential role in limiting the global average temperature increase to below 2°C.Redirecting and advancing technological progress contribute to carbon-free transition solutions.Energy tran...The energy sector has an essential role in limiting the global average temperature increase to below 2°C.Redirecting and advancing technological progress contribute to carbon-free transition solutions.Energy transition is currently one of the most debated issues in the world.This paper reviews and summarizes the current policy projections and their assumptions organized by some major countries in the energy sector,particularly in the coal sector,and provides a detailed discussion on specific and significant socio-technical pathways taken by countries to achieve zero-carbon targets.Their implementation involves restructuring the existing energy system and requires appropriate policy support and sufficient investment in infrastructure development and technological innovation.Some basic principles and countermeasures that have already been implemented by some major emitters,such as India and China,are also discussed,with different transformation pathways.Critical suggestions are also provided,such as implementing best practice policies at the national level,moving to more efficient transition strategies,national and regional cooperation,cross-border energy grid integration,and private sector involvement to reduce carbon emissions from coal-fired power plants,not only by reducing coal consumption but also by introducing various low carbon technologies.展开更多
Distribution networks in China and several other countries are predominantly neutral inefficiently grounding systems(NIGSs),and more than 80%of the faults in distribution networks are single-phase-to-ground(SPG)faults...Distribution networks in China and several other countries are predominantly neutral inefficiently grounding systems(NIGSs),and more than 80%of the faults in distribution networks are single-phase-to-ground(SPG)faults.Because of the weak fault current and imperfect monitoring equipment configurations,methods used to determine the faulty line secti ons with SPG faults in NIGSs are in effective.The developme nt and application of distributi on-level phasor measurement units(PMUs)provide further comprehensive fault information for fault diagnosis in a distribution network.When an SPG fault occurs,the transient energy of the faulted line section tends to be higher than the sum of the transient energies of other line sections.In this regard,transient energy-based fault location algorithms appear to be a promising resolution.In this study,a field test plan was designed and implemented for a 10 kV distribution network.The test results dem on strate the effective ness of the transient en ergy-based SPG locati on method in practical distributi on networks.展开更多
According to the capillary theory,an equivalent capillary model of micro-resistivity imaging logging was built.On this basis,the theoretical models of porosity spectrum(Ф_(i)),permeability spectrum(K_(i))and equivale...According to the capillary theory,an equivalent capillary model of micro-resistivity imaging logging was built.On this basis,the theoretical models of porosity spectrum(Ф_(i)),permeability spectrum(K_(i))and equivalent capillary pressure curve(pe)were established to reflect the reservoir heterogeneity.To promote the application of the theoretical models,the Archie's equation was introduced to establish a general model for quantitatively characterizing bi,K,and pei.Compared with the existing models,it is shown that:(1)the existing porosity spectrum model is the same as the general equation of gi;(2)the Ki model can display the permeability spectrum as compared with Purcell's permeability model;(3)the per model is constructed on a theoretical basis and avoids the limitations of existing models that are built only based on the component of porosity spectrum,as compared with the empirical model of capillary pressure curve.The application in the Permian Maokou Formation of Well TsX in the Central Sichuan paleo-uplift shows that the Ф_(i),K_(i),and p_(ci) models can be effectively applied to the identification of reservoir types,calculation of reservoir properties and pore structure parameters,and evaluation of reservoir heterogeneity.展开更多
基金financial supports from the Youth Innovation Fund of Dalian Institute of Chemical Physics (DICP I202126)the Strategic Priority Research Program of Chinese Academy of Sciences (XDB17020400)。
文摘The oxygen evolution reaction (OER) dominates the efficiency of electrocatalytic water splitting owing to its sluggish kinetics.Perovskite oxides (ABO_(3)) have emerged as promising candidates to accelerate the OER process owing to their high intrinsic activities and tailorable properties.Fe ions in perovskite oxides have been proved to be a highly catalytic element for OER,while some Fe-based perovskites such as SrTi_(0.8)Fe_(0.2)O_(3-δ)(STF) and La_(0.66)Ti_(0.8)Fe_(0.2)O_(3-δ)(LTF) exhibit inferior OER activity.Yet the essential reason is still unclear and the effective method to promote the activity of such perovskite is also lacking.Herein,an in-situ exsolution strategy was proposed to boost the OER by migrating Fe from the bulk to the surface.Significantly enhanced OER activity was achieved on STF and LTF perovskites with surfacedecorated oxygen vacancies and Fe nanoparticles.In addition,theoretical calculation confirmed that the oxygen vacancies and Fe nanoparticle on surface could lower the overpotential of OER by facilitating the adsorption of OH^(-).From this study,migration of the active elements in perovskite is found to be an effective strategy to increase the quantity and activity of active sites,providing new insights and understanding for designing efficient OER catalysts.
基金financial supports from the Strategic Priority Research Program of the Chinese Academy of Sciences(CAS)(XDB17000000)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y201829)the LiaoNing Revitalization Talents Program(XLYC 1801004)。
文摘Developing high active and stable bifunctional electrocatalysts towards oxygen reduction reaction(ORR)and oxygen evolution reaction(OER)is essential for the development of rechargeable Zn-air batteries.Herein,a facile strategy to synthesize the porous carbon layers wrapped CoFe alloy(C/CoFe)through the pyrolysis of a homogeneous mixture containing Co,Fe ions and N-doped carbon quantum dots(Ndoped CQDs)was reported.The prepared carbon layers with multi-level pore structures provides more active sites and optimizes the homogeneity of the electron and mass transport.In addition,the carbon layers,which is doped by Co/Fe/N atoms,is responsible for high ORR activity,while the CoFe alloy plays a vital role in OER performance.The as-synthesized catalyst exhibits an excellent bifunctionality for electrochemical oxygen reactions,which is comparable to the commercial Pt/C and IrO2 benchmarks.Owing to the carbon layers protects CoFe alloy nanoparticles from the harsh environment,the rechargeable Znair battery with the C/CoFe catalyst delivers excellent stability during 20,000 charging-discharging cycles.
基金supported by the Natural Science Foundation of Shandong Province (No.ZR2019MEE078)Education and Teaching Reform Research Project of Shandong University (“Development of an experiment platform to support the intelligent energy courses”)。
文摘Decarbonization of the power sector in China is an essential aspect of the energy transition process to achieve carbon neutrality.The power sector accounts for approximately 40%of China’s total CO_(2) emissions.Accordingly,collaborative optimization in power generation expansion planning(GEP)simultaneously considering economic,environmental,and technological concerns as carbon emissions is necessary.This paper proposes a collaborative mixedinteger linear programming optimization approach for GEP.This minimizes the power system’s operating cost to resolve emission concerns considering energy development strategies,flexible generation,and resource limitations constraints.This research further analyzes the advantages and disadvantages of current GEP techniques.Results show that the main determinants of new investment decisions are carbon emissions,reserve margins,resource availability,fuel consumption,and fuel price.The proposed optimization method is simulated and validated based on China’s power system data.Finally,this study provides policy recommendations on the flexible management of traditional power sources,the market-oriented mechanism of new energy sources,and the integration of new technology to support the attainment of carbon-neutral targets in the current energy transition process.
基金Global Energy Internet Group Co.,Ltd Science and Technology Project(SGGEIG00JYJS2000046)by National Natural Science Foundation of China(51977123).
文摘The energy sector has an essential role in limiting the global average temperature increase to below 2°C.Redirecting and advancing technological progress contribute to carbon-free transition solutions.Energy transition is currently one of the most debated issues in the world.This paper reviews and summarizes the current policy projections and their assumptions organized by some major countries in the energy sector,particularly in the coal sector,and provides a detailed discussion on specific and significant socio-technical pathways taken by countries to achieve zero-carbon targets.Their implementation involves restructuring the existing energy system and requires appropriate policy support and sufficient investment in infrastructure development and technological innovation.Some basic principles and countermeasures that have already been implemented by some major emitters,such as India and China,are also discussed,with different transformation pathways.Critical suggestions are also provided,such as implementing best practice policies at the national level,moving to more efficient transition strategies,national and regional cooperation,cross-border energy grid integration,and private sector involvement to reduce carbon emissions from coal-fired power plants,not only by reducing coal consumption but also by introducing various low carbon technologies.
基金National Key R&D Program of China(2017YFB0902800)Science and Technology Project of State Grid Corporation of China(52094017003D)supported this work.
文摘Distribution networks in China and several other countries are predominantly neutral inefficiently grounding systems(NIGSs),and more than 80%of the faults in distribution networks are single-phase-to-ground(SPG)faults.Because of the weak fault current and imperfect monitoring equipment configurations,methods used to determine the faulty line secti ons with SPG faults in NIGSs are in effective.The developme nt and application of distributi on-level phasor measurement units(PMUs)provide further comprehensive fault information for fault diagnosis in a distribution network.When an SPG fault occurs,the transient energy of the faulted line section tends to be higher than the sum of the transient energies of other line sections.In this regard,transient energy-based fault location algorithms appear to be a promising resolution.In this study,a field test plan was designed and implemented for a 10 kV distribution network.The test results dem on strate the effective ness of the transient en ergy-based SPG locati on method in practical distributi on networks.
基金Supported by the National Natural Science Foundation of China(U2003102,41974117)China National Science and Technology Major Project(2016ZX05052001).
文摘According to the capillary theory,an equivalent capillary model of micro-resistivity imaging logging was built.On this basis,the theoretical models of porosity spectrum(Ф_(i)),permeability spectrum(K_(i))and equivalent capillary pressure curve(pe)were established to reflect the reservoir heterogeneity.To promote the application of the theoretical models,the Archie's equation was introduced to establish a general model for quantitatively characterizing bi,K,and pei.Compared with the existing models,it is shown that:(1)the existing porosity spectrum model is the same as the general equation of gi;(2)the Ki model can display the permeability spectrum as compared with Purcell's permeability model;(3)the per model is constructed on a theoretical basis and avoids the limitations of existing models that are built only based on the component of porosity spectrum,as compared with the empirical model of capillary pressure curve.The application in the Permian Maokou Formation of Well TsX in the Central Sichuan paleo-uplift shows that the Ф_(i),K_(i),and p_(ci) models can be effectively applied to the identification of reservoir types,calculation of reservoir properties and pore structure parameters,and evaluation of reservoir heterogeneity.
