Ti-10V-2Fe-3Al alloy with fine-grainedβphases was fabricated by friction stir processing with opti-mized processing parameters.The superplastic behavior of the specimens was investigated by tensile deformation at dif...Ti-10V-2Fe-3Al alloy with fine-grainedβphases was fabricated by friction stir processing with opti-mized processing parameters.The superplastic behavior of the specimens was investigated by tensile deformation at different strain rates and temperatures,and an optimal superplastic elongation of 634%was achieved at 700℃ and 3×10^(-4)/s.An annealing treatment at 650℃ for 60 min showed a mi-crostructure withαprecipitates distributed in theβmatrix in the friction stir specimen.Such pre-heat treatment improves the superplasticity of the specimen,achieving an elongation of up to 807%at 750℃ and 3×10^(-4)/s.The influences of tensile temperatures and strain rates on the microstructural evolution,such as grain size variation,grain morphology,and phase transformations,were discussed.The super-plastic deformation behavior of fine-grained Ti-10V-2Fe-3Al alloy is controlled by grain boundary sliding and accompanied by dynamic phase transformation and recrystallization.展开更多
The grain boundary diffusion process(GBDP)has proven to be an effective method for enhancing the coercivity of sintered Nd-Fe-B magnets.However,the limited diffusion depth and thicker shell struc-ture have impeded the...The grain boundary diffusion process(GBDP)has proven to be an effective method for enhancing the coercivity of sintered Nd-Fe-B magnets.However,the limited diffusion depth and thicker shell struc-ture have impeded the further development of magnetic properties.Currently,the primary debates re-garding the mechanism of GBDP with Tb revolve around the dissolution-solidification mechanism and the atomic substitution mechanism.To clarify this mechanism,the microstructure evolution of sintered Nd-Fe-B magnets during the heating process of GBDP has been systematically studied by quenching at different tem peratures.In this study,it was found that the formation of TbFe_(2) phase is related to the dis-solution of _(2)Fe_(14)B grains during GBDP with Tb.The theory of mixing heat and phase separation further confirms that the Nd_(2)Fe_(14)B phase dissolves to form a mixed phase of Nd and TbFe_(2),which then solidifies into the(Nd,Tb)_(2)Fe_(14)B phase.Based on the discovery of the TbFe_(2) phase,the dissolution-solidification mechanism is considered the primary mechanism for GBDP.This is supported by the elemental content of the two typical core-shell structures observed.展开更多
Erratum to:International Journal of Minerals,Metallurgy and Materials Volume 31,Number 1,January 2024,Page 186 https://doi.org/10.1007/s12613-023-2744-0 The original version of this article unfortunately contained thr...Erratum to:International Journal of Minerals,Metallurgy and Materials Volume 31,Number 1,January 2024,Page 186 https://doi.org/10.1007/s12613-023-2744-0 The original version of this article unfortunately contained three mistakes.The presentation of Fig.8 in original version was incorrect.The correct version is given below.展开更多
Estimating the multi-year average air-sea CO_(2) flux over a large area usually involves the use of monthly mean variables from the atmosphere and ocean.Ignoring sub-monthly processes will blur the oceanic carbon cycl...Estimating the multi-year average air-sea CO_(2) flux over a large area usually involves the use of monthly mean variables from the atmosphere and ocean.Ignoring sub-monthly processes will blur the oceanic carbon cycle,especially when the synoptic and sub-seasonal scale processes are significant,like in the South China Sea(SCS).Based on an empirical relationship between the partial pressure of CO_(2) in water and the sea surface temperature(SST),we recalculated the air-sea CO_(2) flux of the SCS with daily products of atmospheric reanalysis and SST.Our results show that the sub-monthly process contributes 10%of the total CO_(2) flux of the SCS and can even alter the sign of the CO_(2) flux in the spring.In the near-surface coupling process,intramonthly variations in surface winds play the dominant role,except in regions with significant ocean eddies.The co-spectrum analysis of SST and wind speed reveals the most essential oscillation of>20 days.Therefore,a product of the sea surface environment for 10-day intervals can better estimate the air-sea CO_(2) flux over the SCS than monthly data.展开更多
Low-salinity water(LSW)and CO_(2) could be combined to perform better in a hydrocarbon reservoir due to their synergistic advantages for enhanced oil recovery(EOR);however,its microscopic recovery mechanisms have not ...Low-salinity water(LSW)and CO_(2) could be combined to perform better in a hydrocarbon reservoir due to their synergistic advantages for enhanced oil recovery(EOR);however,its microscopic recovery mechanisms have not been well understood due to the nature of these two fluids and their physical reactions in the presence of reservoir fluids and porous media.In this work,well-designed and inte-grated experiments have been performed for the first time to characterize the in-situ formation of micro-dispersions and identify their EOR roles during a LSW-alternating-CO_(2)(CO_(2)-LSWAG)process under various conditions.Firstly,by measuring water concentration and performing the Fourier transform infrared spectroscopy(FT-IR)analysis,the in-situ formation of micro-dispersions induced by polar and acidic materials was identified.Then,displacement experiments combining with nuclear magnetic resonance(NMR)analysis were performed with two crude oil samples,during which wettability,interfacial tension(IFT),CO_(2) dissolution,and CO_(2) diffusion were quantified.During a CO_(2)-LSWAG pro-cess,the in-situ formed micro-dispersions dictate the oil recovery,while the presence of clay minerals,electrical double-layer(EDL)expansion and multiple ion exchange(MIE)are found to contribute less.Such formed micro-dispersions are induced by CO_(2) via diffusion to mobilize the CO_(2)-diluted oil,alter the rock wettability towards more water-wet,and minimize the density contrast between crude oil and water.展开更多
Manganese ion(Mn^(2+))was generated from metallurgical,steel making and chemical industries.It could affect microbial activity and community structure after entering sewage treatment plant.The effect of Mn^(2+)on the ...Manganese ion(Mn^(2+))was generated from metallurgical,steel making and chemical industries.It could affect microbial activity and community structure after entering sewage treatment plant.The effect of Mn^(2+)on the pollutant removal,metal distribution patterns and composition of microbial communities were investigated in a an anaerobic/anoxic/oxic(A^(2)O)process.The results showed that when Mn^(2+)concentration was 5 mg/L,the efficiencies for the removal of chemical oxygen demand(COD),total nitrogen(TN)and total phosphorus(TP)attained remarkable levels of 96%,93%,and 99%,respectively.In the sludge,the distribution pattern of Mn^(2+)concentration was tightly bound extracellular polymeric substances(TB-EPS)>supernatant>loosely bound EPS(LB-EPS)>soluble microbial products(SMP).Mn^(2+)was found to enrich and accumulate in the microorganism cells.In addition,Mn^(2+)was mainly found in residual fractions and reducible fractions of pellet that manganese was present.The pellet was discovered to contain a substantial quantity of manganese,which was present in various oxidation states,including Mn^(4+),Mn^(3+)and Mn^(2+).The escalating levels of Mn^(2+)led to a reduction in the richness and diversity of microbial communities inhabiting various regions of the A^(2)O reactor.Nonetheless,the uniformity experienced only subtle alterations.Proteobacteria and Bacteroidetes emerged as the leading phyla within the microbial ecosystem,experiencing a steady rise in their respective proportions.The dominant bacterial groups,Azospira and Dechromonas,experienced an incremental increase in their relative prevalence,which played a constructive role in the process of pollutant removal.展开更多
基金financially supported by the National Natural Science Foundation of China(No.52105373)the China Scholarship Council(No.202106020094).
文摘Ti-10V-2Fe-3Al alloy with fine-grainedβphases was fabricated by friction stir processing with opti-mized processing parameters.The superplastic behavior of the specimens was investigated by tensile deformation at different strain rates and temperatures,and an optimal superplastic elongation of 634%was achieved at 700℃ and 3×10^(-4)/s.An annealing treatment at 650℃ for 60 min showed a mi-crostructure withαprecipitates distributed in theβmatrix in the friction stir specimen.Such pre-heat treatment improves the superplasticity of the specimen,achieving an elongation of up to 807%at 750℃ and 3×10^(-4)/s.The influences of tensile temperatures and strain rates on the microstructural evolution,such as grain size variation,grain morphology,and phase transformations,were discussed.The super-plastic deformation behavior of fine-grained Ti-10V-2Fe-3Al alloy is controlled by grain boundary sliding and accompanied by dynamic phase transformation and recrystallization.
基金supported by the National Key Research and Development Program of China(2022YFB3505503)the National Natural Science Foundation of China(52201230)+2 种基金the Key R&D Program of Shandong Province(2022CXGC020307)the China Postdoctoral Science Foundation(2022M71204)the Beijing NOVA Program(Z211100002121092).
文摘The grain boundary diffusion process(GBDP)has proven to be an effective method for enhancing the coercivity of sintered Nd-Fe-B magnets.However,the limited diffusion depth and thicker shell struc-ture have impeded the further development of magnetic properties.Currently,the primary debates re-garding the mechanism of GBDP with Tb revolve around the dissolution-solidification mechanism and the atomic substitution mechanism.To clarify this mechanism,the microstructure evolution of sintered Nd-Fe-B magnets during the heating process of GBDP has been systematically studied by quenching at different tem peratures.In this study,it was found that the formation of TbFe_(2) phase is related to the dis-solution of _(2)Fe_(14)B grains during GBDP with Tb.The theory of mixing heat and phase separation further confirms that the Nd_(2)Fe_(14)B phase dissolves to form a mixed phase of Nd and TbFe_(2),which then solidifies into the(Nd,Tb)_(2)Fe_(14)B phase.Based on the discovery of the TbFe_(2) phase,the dissolution-solidification mechanism is considered the primary mechanism for GBDP.This is supported by the elemental content of the two typical core-shell structures observed.
文摘Erratum to:International Journal of Minerals,Metallurgy and Materials Volume 31,Number 1,January 2024,Page 186 https://doi.org/10.1007/s12613-023-2744-0 The original version of this article unfortunately contained three mistakes.The presentation of Fig.8 in original version was incorrect.The correct version is given below.
基金supported by the National Key Research and Development Program of China (Grant No. 2023YFF0805502)the Southern Marine Science and Engineering Guangdong Laboratory (Zhuhai) (Grant No. SML2022SP401)+1 种基金the Ocean Negative Carbon Emissions (ONCE) Programthe National Natural Science Foundation of China (Grant No. 42305078)
文摘Estimating the multi-year average air-sea CO_(2) flux over a large area usually involves the use of monthly mean variables from the atmosphere and ocean.Ignoring sub-monthly processes will blur the oceanic carbon cycle,especially when the synoptic and sub-seasonal scale processes are significant,like in the South China Sea(SCS).Based on an empirical relationship between the partial pressure of CO_(2) in water and the sea surface temperature(SST),we recalculated the air-sea CO_(2) flux of the SCS with daily products of atmospheric reanalysis and SST.Our results show that the sub-monthly process contributes 10%of the total CO_(2) flux of the SCS and can even alter the sign of the CO_(2) flux in the spring.In the near-surface coupling process,intramonthly variations in surface winds play the dominant role,except in regions with significant ocean eddies.The co-spectrum analysis of SST and wind speed reveals the most essential oscillation of>20 days.Therefore,a product of the sea surface environment for 10-day intervals can better estimate the air-sea CO_(2) flux over the SCS than monthly data.
基金support by The CO_(2) Flooding and Storage Safety Monitoring Technology(Grant 2023YFB4104200)The Dynamic Evolution of Marine CO_(2) Geological Sequestration Bodies and The Mechanism of Sequestration Efficiency Enhancement(Grant U23B2090)The Efficient Development Technology and Demonstration Project of Offshore CO_(2) Flooding(Grant KJGG-2022-12-CCUS-0203).
文摘Low-salinity water(LSW)and CO_(2) could be combined to perform better in a hydrocarbon reservoir due to their synergistic advantages for enhanced oil recovery(EOR);however,its microscopic recovery mechanisms have not been well understood due to the nature of these two fluids and their physical reactions in the presence of reservoir fluids and porous media.In this work,well-designed and inte-grated experiments have been performed for the first time to characterize the in-situ formation of micro-dispersions and identify their EOR roles during a LSW-alternating-CO_(2)(CO_(2)-LSWAG)process under various conditions.Firstly,by measuring water concentration and performing the Fourier transform infrared spectroscopy(FT-IR)analysis,the in-situ formation of micro-dispersions induced by polar and acidic materials was identified.Then,displacement experiments combining with nuclear magnetic resonance(NMR)analysis were performed with two crude oil samples,during which wettability,interfacial tension(IFT),CO_(2) dissolution,and CO_(2) diffusion were quantified.During a CO_(2)-LSWAG pro-cess,the in-situ formed micro-dispersions dictate the oil recovery,while the presence of clay minerals,electrical double-layer(EDL)expansion and multiple ion exchange(MIE)are found to contribute less.Such formed micro-dispersions are induced by CO_(2) via diffusion to mobilize the CO_(2)-diluted oil,alter the rock wettability towards more water-wet,and minimize the density contrast between crude oil and water.
基金supported by Jilin Provincial Department of Education Science and Technology Project(No.JJKH20230152KJ)the Doctoral Research Initiation Fund(No.BSJXM-2022215).
文摘Manganese ion(Mn^(2+))was generated from metallurgical,steel making and chemical industries.It could affect microbial activity and community structure after entering sewage treatment plant.The effect of Mn^(2+)on the pollutant removal,metal distribution patterns and composition of microbial communities were investigated in a an anaerobic/anoxic/oxic(A^(2)O)process.The results showed that when Mn^(2+)concentration was 5 mg/L,the efficiencies for the removal of chemical oxygen demand(COD),total nitrogen(TN)and total phosphorus(TP)attained remarkable levels of 96%,93%,and 99%,respectively.In the sludge,the distribution pattern of Mn^(2+)concentration was tightly bound extracellular polymeric substances(TB-EPS)>supernatant>loosely bound EPS(LB-EPS)>soluble microbial products(SMP).Mn^(2+)was found to enrich and accumulate in the microorganism cells.In addition,Mn^(2+)was mainly found in residual fractions and reducible fractions of pellet that manganese was present.The pellet was discovered to contain a substantial quantity of manganese,which was present in various oxidation states,including Mn^(4+),Mn^(3+)and Mn^(2+).The escalating levels of Mn^(2+)led to a reduction in the richness and diversity of microbial communities inhabiting various regions of the A^(2)O reactor.Nonetheless,the uniformity experienced only subtle alterations.Proteobacteria and Bacteroidetes emerged as the leading phyla within the microbial ecosystem,experiencing a steady rise in their respective proportions.The dominant bacterial groups,Azospira and Dechromonas,experienced an incremental increase in their relative prevalence,which played a constructive role in the process of pollutant removal.
