The low-cost Fe-Cu,Fe-Ni,and Cu-based high-entropy alloys exhibit a widespread utilization prospect.However,these potential applications have been limited by their low strength.In this study,a novel Fe_(31)Cu_(31)Ni_(...The low-cost Fe-Cu,Fe-Ni,and Cu-based high-entropy alloys exhibit a widespread utilization prospect.However,these potential applications have been limited by their low strength.In this study,a novel Fe_(31)Cu_(31)Ni_(28)Al_(4)Ti_(3)Co_(3) immiscible high-entropy alloy(HEA)was developed.After vacuum arc melting and copper mold suction casting,this HEA exhibits a unique phase separation microstructure,which consists of striped Cu-rich regions and Fe-rich region.Further magnification of the striped Cu-rich region reveals that it is composed of a Cu-rich dot-like phase and a Fe-rich region.The aging alloy is further strengthened by a L1_(2)-Ni_(3)(AlTi)nanoprecipitates,achieving excellent yield strength(1185 MPa)and uniform ductility(~8.8%).The differential distribution of the L1_(2) nanoprecipitate in the striped Cu-rich region and the external Fe-rich region increased the strength difference between these two regions,which increased the strain gradient and thus improved hetero-deformation induced(HDI)hardening.This work provides a new route to improve the HDI hardening of Fe-Cu alloys.展开更多
以转"全鱼"生长激素基因鲤(Cyprinus carpio L.)和野生对照鲤为对象,采用454高通量测序技术对其肠道微生物16S r RNA基因进行测序并分析了3个不同发育阶段微生物群落结构的变化,进而探讨了转基因鲤与对照鲤肠道微生物群落的...以转"全鱼"生长激素基因鲤(Cyprinus carpio L.)和野生对照鲤为对象,采用454高通量测序技术对其肠道微生物16S r RNA基因进行测序并分析了3个不同发育阶段微生物群落结构的变化,进而探讨了转基因鲤与对照鲤肠道微生物群落的差异。基于转基因鲤和对照鲤不同发育时期(6日龄、2月龄、5月龄)肠道微生物群落组成的DCA排序分析显示,2月龄转基因鲤与对照鲤肠道微生物组成不同。Alpha多样性及均匀度都显示转基因鲤肠道微生物多样性高于对照鲤。从门水平的比较分析发现,转基因鲤肠道中存在较多的厚壁菌门(Firmicutes)细菌,而对照鲤中拟杆菌门(Bacteroidetes)细菌较多,其中2月龄转基因鲤肠道内Bacteroidetes/Firmicutes比值低于对照鲤。研究结果表明,在所分析的3个发育时期,转基因鲤的肠道微生物组成与对照鲤相比发生了改变,且在2月龄时存在差异。该研究为进一步揭示转基因鱼肠道微生物与宿主的相互影响和作用机制提供了很好的参考。展开更多
基金Projects(52001083,52171111,U2141207)supported by the National Natural Science Foundation of ChinaProject(LH2020E060)supported by the Natural Science Foundation of Heilongjiang,China。
文摘The low-cost Fe-Cu,Fe-Ni,and Cu-based high-entropy alloys exhibit a widespread utilization prospect.However,these potential applications have been limited by their low strength.In this study,a novel Fe_(31)Cu_(31)Ni_(28)Al_(4)Ti_(3)Co_(3) immiscible high-entropy alloy(HEA)was developed.After vacuum arc melting and copper mold suction casting,this HEA exhibits a unique phase separation microstructure,which consists of striped Cu-rich regions and Fe-rich region.Further magnification of the striped Cu-rich region reveals that it is composed of a Cu-rich dot-like phase and a Fe-rich region.The aging alloy is further strengthened by a L1_(2)-Ni_(3)(AlTi)nanoprecipitates,achieving excellent yield strength(1185 MPa)and uniform ductility(~8.8%).The differential distribution of the L1_(2) nanoprecipitate in the striped Cu-rich region and the external Fe-rich region increased the strength difference between these two regions,which increased the strain gradient and thus improved hetero-deformation induced(HDI)hardening.This work provides a new route to improve the HDI hardening of Fe-Cu alloys.
文摘以转"全鱼"生长激素基因鲤(Cyprinus carpio L.)和野生对照鲤为对象,采用454高通量测序技术对其肠道微生物16S r RNA基因进行测序并分析了3个不同发育阶段微生物群落结构的变化,进而探讨了转基因鲤与对照鲤肠道微生物群落的差异。基于转基因鲤和对照鲤不同发育时期(6日龄、2月龄、5月龄)肠道微生物群落组成的DCA排序分析显示,2月龄转基因鲤与对照鲤肠道微生物组成不同。Alpha多样性及均匀度都显示转基因鲤肠道微生物多样性高于对照鲤。从门水平的比较分析发现,转基因鲤肠道中存在较多的厚壁菌门(Firmicutes)细菌,而对照鲤中拟杆菌门(Bacteroidetes)细菌较多,其中2月龄转基因鲤肠道内Bacteroidetes/Firmicutes比值低于对照鲤。研究结果表明,在所分析的3个发育时期,转基因鲤的肠道微生物组成与对照鲤相比发生了改变,且在2月龄时存在差异。该研究为进一步揭示转基因鱼肠道微生物与宿主的相互影响和作用机制提供了很好的参考。
