High-nitrogen stainless bearing steel(HNSBS)with ultra-high tensile strength(∼2403 MPa)and good toughness(∼80.0 J)was obtained by V-microalloying,overcoming the strength-toughness trade-off of conventional V-free HN...High-nitrogen stainless bearing steel(HNSBS)with ultra-high tensile strength(∼2403 MPa)and good toughness(∼80.0 J)was obtained by V-microalloying,overcoming the strength-toughness trade-off of conventional V-free HNSBS.In this work,since V-microalloying facilitated the enrichment of interstitial atoms(C and N)in precipitates,the content of interstitial atoms in the matrix was reduced accordingly(i.e.,interstitial partitioning).On the one hand,V-microalloying reduced the substantial intergranular precipitates and transformed the precipitates from M_(23)C_(6)+M_(2)N into V-containing M_(23)C_(6)+M_(2)N+MN with multi-scale particle sizes,causing a coupling strengthening effect,which contributed to the toughness and additional strength increase.On the other hand,V-microalloying controlled interstitial partitioning,effectively refined coarse retained austenite(RA),increased the fraction of dislocation martensite,and reduced the fraction of twin martensite.The more film-like RA and dislocation martensite with high dislocation density coordinated plastic deformation and prevented crack propagation,thus obviously enhancing the strength and toughness of 0.2 V steel.This study provides a new route to develop high-performance HNSBS for aerospace applications.展开更多
Stomata play a crucial role in plants by controlling water status and responding to drought stress.However,simultaneously improving stomatal opening and drought tolerance has proven to be a significant challenge.To ad...Stomata play a crucial role in plants by controlling water status and responding to drought stress.However,simultaneously improving stomatal opening and drought tolerance has proven to be a significant challenge.To address this issue,we employed the OnGuard quantitative model,which accurately represents the mechanics and coordination of ion transporters in guard cells.With the guidance of OnGuard,we successfully engineered plants that overexpressed the main tonoplast Ca^(2+)-ATPase gene,ACA11,which promotes stomatal opening and enhances plant growth.Surprisingly,these transgenic plants also exhibited improved drought tolerance due to reduced water loss through their stomata.Again,OnGuard assisted us in understanding the mechanism behind the unexpected stomatal behaviors observed in the ACA11 overexpressing plants.Our study revealed that the overexpression of ACA11 facilitated the accumulation of Ca^(2+)in the vacuole,thereby influencing Ca^(2+)storage and leading to an enhanced Ca^(2+)elevation in response to abscisic acid.This regulatory cascade finely tunes stomatal responses,ultimately leading to enhanced drought tolerance.Our findings underscore the importance of tonoplast Ca^(2+)-ATPase in manipulating stomatal behavior and improving drought tolerance.Furthermore,these results highlight the diverse functions of tonoplast-localized ACA11 in response to different conditions,emphasizing its potential for future applications in plant enhancement.展开更多
基金sponsored by the National Natural Science Foundation of China(Grant Nos.U1960203,52004060,and 52174308)Fundamental Research Funds for the Central Universities(Grant Nos.N2125017 and N2225031)+1 种基金Program of Introducing Talents of Discipline to Universities(Grant No.B21001)Liaoning Pilot Base Project(No.2022JH24/10200026)。
文摘High-nitrogen stainless bearing steel(HNSBS)with ultra-high tensile strength(∼2403 MPa)and good toughness(∼80.0 J)was obtained by V-microalloying,overcoming the strength-toughness trade-off of conventional V-free HNSBS.In this work,since V-microalloying facilitated the enrichment of interstitial atoms(C and N)in precipitates,the content of interstitial atoms in the matrix was reduced accordingly(i.e.,interstitial partitioning).On the one hand,V-microalloying reduced the substantial intergranular precipitates and transformed the precipitates from M_(23)C_(6)+M_(2)N into V-containing M_(23)C_(6)+M_(2)N+MN with multi-scale particle sizes,causing a coupling strengthening effect,which contributed to the toughness and additional strength increase.On the other hand,V-microalloying controlled interstitial partitioning,effectively refined coarse retained austenite(RA),increased the fraction of dislocation martensite,and reduced the fraction of twin martensite.The more film-like RA and dislocation martensite with high dislocation density coordinated plastic deformation and prevented crack propagation,thus obviously enhancing the strength and toughness of 0.2 V steel.This study provides a new route to develop high-performance HNSBS for aerospace applications.
基金supported by the Zhejiang Provincial Natural Science Foundation(LR21C020001)the National Natural Science Foundation of China(32372017,31871537 and U2003115)+3 种基金the Hainan Seed Industry Laboratory(B21HJ0220)to Y.W.the Biotechnology and Biological Sciences Research Council(BBSRC)grants(BB/W001217/1)to M.R.B.and R.K.BBSRC grants(BB/S017348/1)Royal Society University Research Fellowship awards(URFR 211002)to R.K.
文摘Stomata play a crucial role in plants by controlling water status and responding to drought stress.However,simultaneously improving stomatal opening and drought tolerance has proven to be a significant challenge.To address this issue,we employed the OnGuard quantitative model,which accurately represents the mechanics and coordination of ion transporters in guard cells.With the guidance of OnGuard,we successfully engineered plants that overexpressed the main tonoplast Ca^(2+)-ATPase gene,ACA11,which promotes stomatal opening and enhances plant growth.Surprisingly,these transgenic plants also exhibited improved drought tolerance due to reduced water loss through their stomata.Again,OnGuard assisted us in understanding the mechanism behind the unexpected stomatal behaviors observed in the ACA11 overexpressing plants.Our study revealed that the overexpression of ACA11 facilitated the accumulation of Ca^(2+)in the vacuole,thereby influencing Ca^(2+)storage and leading to an enhanced Ca^(2+)elevation in response to abscisic acid.This regulatory cascade finely tunes stomatal responses,ultimately leading to enhanced drought tolerance.Our findings underscore the importance of tonoplast Ca^(2+)-ATPase in manipulating stomatal behavior and improving drought tolerance.Furthermore,these results highlight the diverse functions of tonoplast-localized ACA11 in response to different conditions,emphasizing its potential for future applications in plant enhancement.
