This paper introduce the advances in study of antibacterial effects of natural medicines in the past ten years.The antibacterial components of natural medicines mainly include flavonoids,terpenoids,alkaloids,lignans,p...This paper introduce the advances in study of antibacterial effects of natural medicines in the past ten years.The antibacterial components of natural medicines mainly include flavonoids,terpenoids,alkaloids,lignans,phenols,etc..This paper is intended to provide data reference for the research and development of new natural antibacterial medicines.展开更多
Alloys with combined outstanding strength and excellent ductility are highly desirable for many structural applications.However,alloys subjected to deformation at very high strain rates and/or cryogenic temperatures u...Alloys with combined outstanding strength and excellent ductility are highly desirable for many structural applications.However,alloys subjected to deformation at very high strain rates and/or cryogenic temperatures usually suffer from very limited ductility.Here,we demonstrate that a bulk CrCoNi medium-entropy alloy presents exceptional combination of high strength and excellent ductility during deformation at high strain rates over a wide temperature range.Full tensile stress-strain curves at a high strain rate of 2000s^(-1) and temperatures down to 77 K were successfully obtained using an electromagnetic Hopkinson tension bar system attached with a cooling device,revealing high true ultimate tensile strength(σ_(UTS,T))of 1.8 GPa and true strain of~54% at σ_(UTS,T).These outstanding mechanical properties were mainly attributed to profuse deformation twinning.Both high strain rate and cryogenic temperature promoted deformation twinning.Grain refinement caused by deformation twinning,dislocation slip and dynamic recrystallisation added to work hardening and the excellent tensile strain.展开更多
基金National Key Research and Development Program of China(2017YFC1700705)Sichuan Provincial Scholars for Science and Technology Activities for Overseas Researchers(2018-68)+1 种基金Research Project of Sichuan Province(2019YFS0191)Innovating Research Program of Postgraduates of Southwest Minzu University(CX2018SZ86).
文摘This paper introduce the advances in study of antibacterial effects of natural medicines in the past ten years.The antibacterial components of natural medicines mainly include flavonoids,terpenoids,alkaloids,lignans,phenols,etc..This paper is intended to provide data reference for the research and development of new natural antibacterial medicines.
基金support from the Australian Microscopy and Microanalysis Research Facility node at the University of Sydneysupported by the Australian Research Council(DP190102243)。
文摘Alloys with combined outstanding strength and excellent ductility are highly desirable for many structural applications.However,alloys subjected to deformation at very high strain rates and/or cryogenic temperatures usually suffer from very limited ductility.Here,we demonstrate that a bulk CrCoNi medium-entropy alloy presents exceptional combination of high strength and excellent ductility during deformation at high strain rates over a wide temperature range.Full tensile stress-strain curves at a high strain rate of 2000s^(-1) and temperatures down to 77 K were successfully obtained using an electromagnetic Hopkinson tension bar system attached with a cooling device,revealing high true ultimate tensile strength(σ_(UTS,T))of 1.8 GPa and true strain of~54% at σ_(UTS,T).These outstanding mechanical properties were mainly attributed to profuse deformation twinning.Both high strain rate and cryogenic temperature promoted deformation twinning.Grain refinement caused by deformation twinning,dislocation slip and dynamic recrystallisation added to work hardening and the excellent tensile strain.
