A high-strength magnesium alloy containing Yb was prepared through a simple hot extrusion process.The effect of Yb addition on dynamic precipitation,texture evolution,dynamic recrystallization mechanisms,deformation m...A high-strength magnesium alloy containing Yb was prepared through a simple hot extrusion process.The effect of Yb addition on dynamic precipitation,texture evolution,dynamic recrystallization mechanisms,deformation mechanisms,and strengthening mechanisms in as-extruded Mg-4 Sm-3 Gd(-2 Yb)-0.5 Zr(SGY0,SGY2)alloys was systematically investigated.The results indicated that the average grain size decreased from 4.17μm to 1.48μm with the addition of Yb.This extreme grain refinement greatly enhances the strength.The addition of Yb significantly facilitated the phase precipitation,but did not change the texture type.The non-dynamic recrystallized(un DRXed)grains exhibited a strong basal plane texture of<0110>parallel to the extrusion direction(ED),while the dynamic recrystallized(DRXed)grains showed a weaker rare earth texture,characterized by<1212>//ED.Moreover,the as-extruded SGY0 and SGY2 alloys predominantly undergo continuous dynamic recrystallization(CDRX),and some DRXed grains exhibit a discontinuous dynamic recrystallization mechanism(DDRX).In addition,the addition of Yb facilitates the activation of non-basal plane slip.The dislocation types in the as-extruded SGY0 and SGY2 alloys include(a),(c)and(c+a)dislocations.However,the SGY2 alloy exhibits a relatively high dislocation density,which contributes to the enhancement of the strength.Extreme grain refinement and the dispersion of nanoscale second-phase particles are key factors in increasing the strength.展开更多
Orbital hybridization plays a crucial role in catalytic processes,yet elucidating its mechanism remains a significant challenge.Here,we have developed a strategy for the formation of Yb-C bond by unconventional p-d or...Orbital hybridization plays a crucial role in catalytic processes,yet elucidating its mechanism remains a significant challenge.Here,we have developed a strategy for the formation of Yb-C bond by unconventional p-d orbital hybridization,which induced carbon nitride modified by rare-earth metal element Yb.The optimal sample exhibits catalytic performance 11.2 times greater than that of g-C_(3)N_(4)with N vacancies(NvCN).Yb-C bond and N vacancies reduced the energy barrier and optimized the rate-determining step(*COO+*H→*CO+*OH).Additionally,the intense Yb-C interaction created a specific electrons bridge,which accelerated the transfer rate of electrons on the photocatalytic surface.Next,the CO_(2) conversion reaction mechanism was studied by in situ infrared spectroscopy and theoretical calculations,and the unconventional p-d orbital hybridization contributed to the generation of vital intermediate*CO.This study provides a theoretical basis for designing single-atom photocatalysts for the reduction of CO_(2).展开更多
文摘核因子(Nuclear Factor-Y,NF-Y)是一类能够在植物应对非生物胁迫过程中发挥转录调控作用的转录因子。为探究GmNF-YB2在大豆应对非生物胁迫过程中的功能和分子调控机制,本研究从大豆中克隆GmNF-YB2基因并对其进行生物信息学分析,采用实时荧光定量PCR(qRT-PCR)方法对GmNF-YB2的表达量进行检测,通过酵母双杂交方法分析GmNF-YB2蛋白与GmNF-YC6蛋白和GmNF-YC15蛋白的互作情况。结果显示:以大豆叶片cDNA为模板,PCR扩增获得678 bp GmNF-YB2基因序列。生物信息学分析结果显示,GmNF-YB2基因编码1个含有225个氨基酸的蛋白质,预测分子量为24.66 kD,等电点为6.97,是不稳定的亲水性蛋白质,定位于细胞核中;GmNF-YB2蛋白序列中含有一段保守的组蛋白折叠基序HFM。蛋白系统进化分析表明,GmNF-YB2与杨树PdNF-YB7和拟南芥AtNF-YB2的亲缘关系最近。qRT-PCR结果显示,GmNF-YB2在大豆幼苗中能够被干旱、盐和低温胁迫诱导表达,GmNF-YB2在大豆茎中的表达量最高。酵母双杂交结果显示,GmNF-YB2蛋白与GmNF-YC6蛋白和GmNF-YC15蛋白均存在互作关系。结果表明GmNF-YB2可能参与大豆对非生物胁迫的应答。
基金financially supported by the National Natural Science Foundation of China(No.52371108,52201119,52203295)Frontier Exploration Project of Longmen Laboratory,China(LMQYTSKT014)the Joint Fund of Henan Science and Technology R&D Plan of China(242103810056)。
文摘A high-strength magnesium alloy containing Yb was prepared through a simple hot extrusion process.The effect of Yb addition on dynamic precipitation,texture evolution,dynamic recrystallization mechanisms,deformation mechanisms,and strengthening mechanisms in as-extruded Mg-4 Sm-3 Gd(-2 Yb)-0.5 Zr(SGY0,SGY2)alloys was systematically investigated.The results indicated that the average grain size decreased from 4.17μm to 1.48μm with the addition of Yb.This extreme grain refinement greatly enhances the strength.The addition of Yb significantly facilitated the phase precipitation,but did not change the texture type.The non-dynamic recrystallized(un DRXed)grains exhibited a strong basal plane texture of<0110>parallel to the extrusion direction(ED),while the dynamic recrystallized(DRXed)grains showed a weaker rare earth texture,characterized by<1212>//ED.Moreover,the as-extruded SGY0 and SGY2 alloys predominantly undergo continuous dynamic recrystallization(CDRX),and some DRXed grains exhibit a discontinuous dynamic recrystallization mechanism(DDRX).In addition,the addition of Yb facilitates the activation of non-basal plane slip.The dislocation types in the as-extruded SGY0 and SGY2 alloys include(a),(c)and(c+a)dislocations.However,the SGY2 alloy exhibits a relatively high dislocation density,which contributes to the enhancement of the strength.Extreme grain refinement and the dispersion of nanoscale second-phase particles are key factors in increasing the strength.
基金financially supported by the National Natural Science Foundation of China(No.52370109)Guangdong Province Scientific Research Platform Project(Nos.2023ZDZX4052,2022ZDZX4046)+3 种基金Shaoguan Science and Technology Projects(No.230616088031998)High Level Talents Introduction Project of"Pearl River Talent Plan"in Guangdong Province(No.2019CX01L308)the Support Scheme of Guangzhou for Leading Talents in Innovation and Entrepreneurship Funding(No.2016015)the Science and Technology Research Program of Chongqing Municipal Education Commission of China(No.KJZDM202400802)
文摘Orbital hybridization plays a crucial role in catalytic processes,yet elucidating its mechanism remains a significant challenge.Here,we have developed a strategy for the formation of Yb-C bond by unconventional p-d orbital hybridization,which induced carbon nitride modified by rare-earth metal element Yb.The optimal sample exhibits catalytic performance 11.2 times greater than that of g-C_(3)N_(4)with N vacancies(NvCN).Yb-C bond and N vacancies reduced the energy barrier and optimized the rate-determining step(*COO+*H→*CO+*OH).Additionally,the intense Yb-C interaction created a specific electrons bridge,which accelerated the transfer rate of electrons on the photocatalytic surface.Next,the CO_(2) conversion reaction mechanism was studied by in situ infrared spectroscopy and theoretical calculations,and the unconventional p-d orbital hybridization contributed to the generation of vital intermediate*CO.This study provides a theoretical basis for designing single-atom photocatalysts for the reduction of CO_(2).
