Due to the existence of water content in shale reservoir,it is quite meaningful to clarify the effect of water content on the methane adsorption capacity(MAC)of shale.However,the role of spatial configuration relation...Due to the existence of water content in shale reservoir,it is quite meaningful to clarify the effect of water content on the methane adsorption capacity(MAC)of shale.However,the role of spatial configuration relationship between organic matter(OM)and clay minerals in the MAC reduction process is still unclear.The Silurian Longmaxi Formation shale samples from the Southern Sichuan Basin in China were prepared at five relative humidity(RH)conditions(0%,16%,41%,76%,99%)and the methane adsorption experiments were conducted on these water-bearing shale samples to clarify the MAC reduction process considering the spatial configuration relationship between clay minerals and OM and establish the empirical model to fit the stages.Total organic carbon(TOC)content and mineral compositions were analyzed and the pore structures of these shale samples were characterized by field-emission scanning electron microscopy(FE-SEM),N2 adsorption and high-pressure mercury intrusion porosimetry(HPMIP).The results showed that the MAC reduction of clay minerals in OM occurred at different RH conditions from that of clay minerals outside OM.Furthermore,the amount of MAC reduction of shale samples prepared at the same RH condition was negatively related with clay content,which indicated the protection role of clay minerals for the MAC of water-bearing shale samples.The MAC reduction process was generally divided into three stages for siliceous and clayey shale samples.And the MAC of OM started to decline during stage(1)for calcareous shale sample mainly because water could enter OM pores more smoothly through hydrophobic pathway provided by carbonate minerals than through hydrophilic clay mineral pores.Overall,this study will contribute to improving the evaluation method of shale gas reserve.展开更多
Based on the stoichiometric method and the free energy minimization method,an ideal model for the reduction of iron oxides by carbon and hydrogen under blast furnace conditions was established,and the reduction effici...Based on the stoichiometric method and the free energy minimization method,an ideal model for the reduction of iron oxides by carbon and hydrogen under blast furnace conditions was established,and the reduction efficiency and theoretical energy consumption of the all-carbon blast furnace and the hydrogen-rich blast furnace were compared.The results show that after the reduction reaction is completed at the bottom of the blast furnace,the gas produced by reduction at 1600℃still has a certain excessive reduction capacity,which is due to the hydrogen brought in by the hydrogen-rich blast as well as the excess carbon monoxide generated by the reaction of the coke and the oxygen brought in by the blast.During the process of the gas with excessive reduction capacity rising from the bottom of the blast furnace and gas reduction process,the excessive reduction capacity of the gas gradually decreases with the increase in the dydrogen content in the blast.In the all-carbon blast furnace,the excess gas reduction capacity is the strongest,and the total energy consumption per ton of iron reduction is the lowest.This shows that,for the current operation mode of the blast furnace,adding hydrogen in the blast furnace cannot reduce the consumption of carbon required for reduction per ton of iron,but rather increases the consumption of carbon.展开更多
Synergistic carbon emission reduction at the urban scale is an inherent requirement for China to realize its carbon emission reduction commitments and promote sustainable and regional synergistic development.Using 16 ...Synergistic carbon emission reduction at the urban scale is an inherent requirement for China to realize its carbon emission reduction commitments and promote sustainable and regional synergistic development.Using 16 prefectural cities in Shandong Province as an example,this study defines and quantifies the regional carbon emission reduction capacity(CERC)based on the synergistic development of carbon emission reduction,environmental protection,and economic growth objectives.The spatial network characteristics of the(CERC)and its drivers were analyzed using social network analysis and quadratic assignment procedure regression methods.The results revealed that the spatial correlation of the CERC among prefectural cities has been increasing over the years.Jinan−Zibo−Qingdao is the center of the network,while the spatial linkage strength in the southwest and northeast of Shandong Province is weak.Geospatial distance and scientific development differences have a significant negative effect on the intensity of spatial association,while differences in economic and informatization developments have a considerable positive impact.Environmental regulatory differences and transportation differences are not significant.This study offers a methodological reference for similar studies in other countries or regions.At the same time,the findings provide a scientific basis for the government to rationally allocate urban resources and promote regional synergistic carbon emission reduction.展开更多
The Ulan Buh Desert is one of the eight deserts in China that provides wind erosion prevention service(i.e.,the ecosystem;vegetation,production,and construction activities that promote sand fixation).It is significant...The Ulan Buh Desert is one of the eight deserts in China that provides wind erosion prevention service(i.e.,the ecosystem;vegetation,production,and construction activities that promote sand fixation).It is significant for the construction of the national ecological barrier,and the protection of the ecological security in the Yellow River and North China.In this study,we selected two representative years(2008 and 2018)and quantified wind erosion prevention service from the Ulan Buh Desert using the RWEQ model.Meanwhile,the HYSPLIT model was used to simulate the spatial flow process from the service supply area to the beneficiary area and to determine its scope.The specific dust reduction amount in the beneficiary area was then calculated.The energy and the time-space relation of wind erosion prevention service in the areas that receive benefits from Ulan Buh Desert were compared before and after implementing environmental restoration measures.The results showed that:(1)the total amount of wind erosion prevention in the Ulan Buh Desert in 2018 was 2.12×10^(10)kg,which was 5.17 times higher than that in 2008;(2)in 2018,the distribution density of the flow path of wind erosion prevention service was lower than that in 2008,and the flow paths in each year were concentrated in the beneficiary areas with the path distribution frequency of less than 10%;(3)the total dust reduction in the downwind area of the Ulan Buh Desert in 2018 was higher than that in 2008,totaling 15.54 million tons.Inner Mongolia Autonomous Region and Shanxi Province had the most significant amount of dust reduction.展开更多
Boron-doped Ketjenblack is attempted as cathode catalyst for non-aqueous rechargeable Li–O2 batteries. The boron-doped Ketjenblack delivers an extremely high discharge capacity of 7193 m Ah/g at a current density of ...Boron-doped Ketjenblack is attempted as cathode catalyst for non-aqueous rechargeable Li–O2 batteries. The boron-doped Ketjenblack delivers an extremely high discharge capacity of 7193 m Ah/g at a current density of 0.1 m A/cm2, and the capacity is about 2.3 times as that of the pristine KB. When the batteries are cycled with different restricted capacity, the boron-doped Ketjenblack based cathodes exhibits higher discharge platform and longer cycle life than Ketjenblack based cathodes. Additionally, the boron-doped Ketjenblack also shows a superior electrocatalytic activity for oxygen reduction in 0.1 mol/L KOH aqueous solution. The improvement in catalytic activity results from the defects and activation sites introduced by boron doping.展开更多
基金supported by the National Science and Technology Major Project of China(No.2017ZX05035-002)the National Natural Science Foundation of China(No.41972145)the Foundation of State Key Laboratory of Petroleum Resources and Prospecting from China University of Petroleum in Beijing(Nos.PRP/indep-3-1707,PRP/indep-3-1615)。
文摘Due to the existence of water content in shale reservoir,it is quite meaningful to clarify the effect of water content on the methane adsorption capacity(MAC)of shale.However,the role of spatial configuration relationship between organic matter(OM)and clay minerals in the MAC reduction process is still unclear.The Silurian Longmaxi Formation shale samples from the Southern Sichuan Basin in China were prepared at five relative humidity(RH)conditions(0%,16%,41%,76%,99%)and the methane adsorption experiments were conducted on these water-bearing shale samples to clarify the MAC reduction process considering the spatial configuration relationship between clay minerals and OM and establish the empirical model to fit the stages.Total organic carbon(TOC)content and mineral compositions were analyzed and the pore structures of these shale samples were characterized by field-emission scanning electron microscopy(FE-SEM),N2 adsorption and high-pressure mercury intrusion porosimetry(HPMIP).The results showed that the MAC reduction of clay minerals in OM occurred at different RH conditions from that of clay minerals outside OM.Furthermore,the amount of MAC reduction of shale samples prepared at the same RH condition was negatively related with clay content,which indicated the protection role of clay minerals for the MAC of water-bearing shale samples.The MAC reduction process was generally divided into three stages for siliceous and clayey shale samples.And the MAC of OM started to decline during stage(1)for calcareous shale sample mainly because water could enter OM pores more smoothly through hydrophobic pathway provided by carbonate minerals than through hydrophilic clay mineral pores.Overall,this study will contribute to improving the evaluation method of shale gas reserve.
基金The author are thankful for the support from the National Natural Science Foundation of China(Nos.U1560203,51704021,and 51274031)Beijing Key Laboratory of Special Melting and Preparation of High-End Metal Materials.
文摘Based on the stoichiometric method and the free energy minimization method,an ideal model for the reduction of iron oxides by carbon and hydrogen under blast furnace conditions was established,and the reduction efficiency and theoretical energy consumption of the all-carbon blast furnace and the hydrogen-rich blast furnace were compared.The results show that after the reduction reaction is completed at the bottom of the blast furnace,the gas produced by reduction at 1600℃still has a certain excessive reduction capacity,which is due to the hydrogen brought in by the hydrogen-rich blast as well as the excess carbon monoxide generated by the reaction of the coke and the oxygen brought in by the blast.During the process of the gas with excessive reduction capacity rising from the bottom of the blast furnace and gas reduction process,the excessive reduction capacity of the gas gradually decreases with the increase in the dydrogen content in the blast.In the all-carbon blast furnace,the excess gas reduction capacity is the strongest,and the total energy consumption per ton of iron reduction is the lowest.This shows that,for the current operation mode of the blast furnace,adding hydrogen in the blast furnace cannot reduce the consumption of carbon required for reduction per ton of iron,but rather increases the consumption of carbon.
基金supported by the Department of Science and Technology of Shandong Province [Grant No.2021SFGC0904-05]Shandong Natural Science Foundation [Grant No.ZR2023MD079]+3 种基金Shandong Province Social Science Planning Research Project [Grant No.22CKRJ04]Taishan Scholar Project [Grant No.tsqn202103010]Zaozhuang Science and Technology Bureau [Grant No.2021GH22]the Key R&D Program of Shandong Province,China [Grant No.2023SFGC0101].
文摘Synergistic carbon emission reduction at the urban scale is an inherent requirement for China to realize its carbon emission reduction commitments and promote sustainable and regional synergistic development.Using 16 prefectural cities in Shandong Province as an example,this study defines and quantifies the regional carbon emission reduction capacity(CERC)based on the synergistic development of carbon emission reduction,environmental protection,and economic growth objectives.The spatial network characteristics of the(CERC)and its drivers were analyzed using social network analysis and quadratic assignment procedure regression methods.The results revealed that the spatial correlation of the CERC among prefectural cities has been increasing over the years.Jinan−Zibo−Qingdao is the center of the network,while the spatial linkage strength in the southwest and northeast of Shandong Province is weak.Geospatial distance and scientific development differences have a significant negative effect on the intensity of spatial association,while differences in economic and informatization developments have a considerable positive impact.Environmental regulatory differences and transportation differences are not significant.This study offers a methodological reference for similar studies in other countries or regions.At the same time,the findings provide a scientific basis for the government to rationally allocate urban resources and promote regional synergistic carbon emission reduction.
基金This research was funded by the National Key Research and De-velopment Program(Grant No.2019YFC0507600/2019YFC0507601)the National Natural Science Foundation of China(Grant No.41671080).
文摘The Ulan Buh Desert is one of the eight deserts in China that provides wind erosion prevention service(i.e.,the ecosystem;vegetation,production,and construction activities that promote sand fixation).It is significant for the construction of the national ecological barrier,and the protection of the ecological security in the Yellow River and North China.In this study,we selected two representative years(2008 and 2018)and quantified wind erosion prevention service from the Ulan Buh Desert using the RWEQ model.Meanwhile,the HYSPLIT model was used to simulate the spatial flow process from the service supply area to the beneficiary area and to determine its scope.The specific dust reduction amount in the beneficiary area was then calculated.The energy and the time-space relation of wind erosion prevention service in the areas that receive benefits from Ulan Buh Desert were compared before and after implementing environmental restoration measures.The results showed that:(1)the total amount of wind erosion prevention in the Ulan Buh Desert in 2018 was 2.12×10^(10)kg,which was 5.17 times higher than that in 2008;(2)in 2018,the distribution density of the flow path of wind erosion prevention service was lower than that in 2008,and the flow paths in each year were concentrated in the beneficiary areas with the path distribution frequency of less than 10%;(3)the total dust reduction in the downwind area of the Ulan Buh Desert in 2018 was higher than that in 2008,totaling 15.54 million tons.Inner Mongolia Autonomous Region and Shanxi Province had the most significant amount of dust reduction.
基金supported by the MOST(Grant nos.2013CB934000and 2014DFG71590)Beijing Municipal Program(Grant no.YETP0157)
文摘Boron-doped Ketjenblack is attempted as cathode catalyst for non-aqueous rechargeable Li–O2 batteries. The boron-doped Ketjenblack delivers an extremely high discharge capacity of 7193 m Ah/g at a current density of 0.1 m A/cm2, and the capacity is about 2.3 times as that of the pristine KB. When the batteries are cycled with different restricted capacity, the boron-doped Ketjenblack based cathodes exhibits higher discharge platform and longer cycle life than Ketjenblack based cathodes. Additionally, the boron-doped Ketjenblack also shows a superior electrocatalytic activity for oxygen reduction in 0.1 mol/L KOH aqueous solution. The improvement in catalytic activity results from the defects and activation sites introduced by boron doping.
