Nanocrystalline Ni-Fe alloy foils were fabricated by using a continuous electrodeposition system, and then they were annealed at different temperatures ranging from room temperature to 650 ℃. A ductile-brittle-ductil...Nanocrystalline Ni-Fe alloy foils were fabricated by using a continuous electrodeposition system, and then they were annealed at different temperatures ranging from room temperature to 650 ℃. A ductile-brittle-ductile evolution of these alloy foils was observed along with the increase of annealing temperature, and was affected by iron content. The first and second transformation took place at below 300 ℃ and over 500 ℃, respectively. Iron improved thermal stability of nanocrystalline Ni-Fe alloys. The XRD data indicated that for Ni100-xFex (x > 55) alloys bcc to fcc phase transformed at 300 ℃ and completely at 500℃.展开更多
LiNi1/3Co1/3Mn1/3O2 and Ce-doped LiNi1/3Co1/3Mn1/3O2 cathode materials were synthesized by a co-precipitation method and solid phase synthesis and characterized using X-ray diffraction(XRD) and scanning electron micro...LiNi1/3Co1/3Mn1/3O2 and Ce-doped LiNi1/3Co1/3Mn1/3O2 cathode materials were synthesized by a co-precipitation method and solid phase synthesis and characterized using X-ray diffraction(XRD) and scanning electron microscopy(SEM).The results indicated that the resultant cathode materials with different Ce content all had a good layer structure and high crystallinity.Electrochemical performance testing of the cathode materials showed that the discharge capacity increased with increasing Ce content while the initial reversible capacity attenuation decreased with Ce doping.When the Ce content of the cathode materials is x=0.2,and the current charge and discharge rate is a constant 0.2 C,the discharge capacity maintained 91% of its initial capacity after cycling 50 times.展开更多
Objective To study the chemical constituents of Swertia cincta. Methods Preparative liquid chromatography was employed. The structures of the compounds were elucidated by spectroscopic analysis. isolated from S. cinct...Objective To study the chemical constituents of Swertia cincta. Methods Preparative liquid chromatography was employed. The structures of the compounds were elucidated by spectroscopic analysis. isolated from S. cincta and identified as Results Three secoiridoid glycosides were 8-methoxyl-eustomorusside （1）, secoiridoids eustomorusside （2）, and eustomoside （3）. Conclusion Compound 1 is a new secoiridoid glycoside. Compounds 2 and 3 are isolated from this plant for the first time.展开更多
Objective:To study the active ingredients in the root bark of Aralia echinocaulis.Methods:Three triterpenoid saponins were separated from the 70%ethanol extracts and purified by column chromatography and their structu...Objective:To study the active ingredients in the root bark of Aralia echinocaulis.Methods:Three triterpenoid saponins were separated from the 70%ethanol extracts and purified by column chromatography and their structures were determined by spectroscopic analysis.Compound 1 and 3 were evaluated for antioxidant activity by the in vitro DPPH free radical scavenging ability and the protective effect of OH-induced DNA oxidative damage.Results:Compound 1 was a new type of triterpenoid saponin,named as echinocaulisaglycone 3-O-β-Dglucopyranoside(echinocaulisaponin A),and it had good antioxidant activity.Compound 2 was similar to compound 1,named as 1-hydroxyl-echinocaulisaglycone 3-O-β-D-glucopyranoside(echinocaulisaponin B).Compound 3 was also a new type of triterpenoid saponin,named as echinocaulisaglyconeⅡ3-O-a-L-arabinopyranosyl-(1’’→4’)-β-D-glucopyranosiduronic acid(echinocaulisaponin C),and its antioxidant activity was weaker than compound 1.Conclusion:In this study,three new compounds were discovered and two of them were carried out in vitro anti-oxidation studies,laying the foundation for further research on the treatment of related diseases(cardiovascular disease,arthritis,age-related macular degeneration,etc.)through anti-oxidation or quenching free radical function.展开更多
文摘Nanocrystalline Ni-Fe alloy foils were fabricated by using a continuous electrodeposition system, and then they were annealed at different temperatures ranging from room temperature to 650 ℃. A ductile-brittle-ductile evolution of these alloy foils was observed along with the increase of annealing temperature, and was affected by iron content. The first and second transformation took place at below 300 ℃ and over 500 ℃, respectively. Iron improved thermal stability of nanocrystalline Ni-Fe alloys. The XRD data indicated that for Ni100-xFex (x > 55) alloys bcc to fcc phase transformed at 300 ℃ and completely at 500℃.
文摘LiNi1/3Co1/3Mn1/3O2 and Ce-doped LiNi1/3Co1/3Mn1/3O2 cathode materials were synthesized by a co-precipitation method and solid phase synthesis and characterized using X-ray diffraction(XRD) and scanning electron microscopy(SEM).The results indicated that the resultant cathode materials with different Ce content all had a good layer structure and high crystallinity.Electrochemical performance testing of the cathode materials showed that the discharge capacity increased with increasing Ce content while the initial reversible capacity attenuation decreased with Ce doping.When the Ce content of the cathode materials is x=0.2,and the current charge and discharge rate is a constant 0.2 C,the discharge capacity maintained 91% of its initial capacity after cycling 50 times.
基金NSFC(NO.21262048)Youth Foundation of Lincang Teachers’College(LCSZL201204)
文摘Objective To study the chemical constituents of Swertia cincta. Methods Preparative liquid chromatography was employed. The structures of the compounds were elucidated by spectroscopic analysis. isolated from S. cincta and identified as Results Three secoiridoid glycosides were 8-methoxyl-eustomorusside （1）, secoiridoids eustomorusside （2）, and eustomoside （3）. Conclusion Compound 1 is a new secoiridoid glycoside. Compounds 2 and 3 are isolated from this plant for the first time.
基金National Natural Science Foundation of China(No.81673769)for funding the experiment。
文摘Objective:To study the active ingredients in the root bark of Aralia echinocaulis.Methods:Three triterpenoid saponins were separated from the 70%ethanol extracts and purified by column chromatography and their structures were determined by spectroscopic analysis.Compound 1 and 3 were evaluated for antioxidant activity by the in vitro DPPH free radical scavenging ability and the protective effect of OH-induced DNA oxidative damage.Results:Compound 1 was a new type of triterpenoid saponin,named as echinocaulisaglycone 3-O-β-Dglucopyranoside(echinocaulisaponin A),and it had good antioxidant activity.Compound 2 was similar to compound 1,named as 1-hydroxyl-echinocaulisaglycone 3-O-β-D-glucopyranoside(echinocaulisaponin B).Compound 3 was also a new type of triterpenoid saponin,named as echinocaulisaglyconeⅡ3-O-a-L-arabinopyranosyl-(1’’→4’)-β-D-glucopyranosiduronic acid(echinocaulisaponin C),and its antioxidant activity was weaker than compound 1.Conclusion:In this study,three new compounds were discovered and two of them were carried out in vitro anti-oxidation studies,laying the foundation for further research on the treatment of related diseases(cardiovascular disease,arthritis,age-related macular degeneration,etc.)through anti-oxidation or quenching free radical function.
