Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosi...Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosin-7-0-(3-D-glucopyranoside) were isolated from the roots of Astragalus mem-branaceus (Fisch.) Bunge. Their structures were established by spectral analysis.展开更多
An epidemiological survey of anisakid nematodes was conducted on 205 specimens of horse mackerel （Trachurus trachurus） and 183 of axillary seabream （Pagellus acarne） captured in the zone between Tangier and Larach...An epidemiological survey of anisakid nematodes was conducted on 205 specimens of horse mackerel （Trachurus trachurus） and 183 of axillary seabream （Pagellus acarne） captured in the zone between Tangier and Larache in the north Atlantic Moroccan＇s coasts. Three species of nematodes were morphologically identified： Anisakis simplex s.l., Hysterothylacium sp., Pseudotarranova sp. According to the season, the nematode most observed in T. trachurus was .4. simplex s.1. （the highest values of prevalence （100%）, the mean intensity （48.6）. Hysterothylacium sp. was the most frequent anisakid in P. acarne with 100% of prevalence and 34.46 of the mean intensity. The infestation parameters were also analyzed according to the host species length, noting a maximum of infected fish by Anisakis simplex s.1. （96%） in samples of horse mackerel larger than 28 cm, while in axiliary seabream, the highest prevalence of infestation by Hysterothylacium sp. （100%） was found in fish more than 29 cm.展开更多
We propose a theoretical model of a nanoemitter for giga- and terahertz-range waves. The model is based on a peapod structure comprising a carbon nanotube with chiral indices （10, 10）. Three encapsulated and partial...We propose a theoretical model of a nanoemitter for giga- and terahertz-range waves. The model is based on a peapod structure comprising a carbon nanotube with chiral indices （10, 10）. Three encapsulated and partially polymerized fuUerene C60 molecules and a positively charged C60 fullerene are trapped inside the nanotube. The motion of the charged fullerene and the radiation frequency were controlled using an external electric field. Stable terahertz radiation at a frequency of 0.36 THz was produced at 300 K with an external electrical field of 10 V/μm. Stable radiation in the gigahertz range was observed at 50 K with an electric field below 10 V/m. A theoretical simulation was performed using the tight-binding molecular dynamics method with a description of the van der Waals interaction by the Morse potential. The system described by the theoretical model was experimentally observed.展开更多
Bimetallic PtxCuy nanocrystals （NCs） with well-defined hexa-pod morphology were synthesized via a wet chemistry approach. The as-synthesized convex NCs with dimensions of around 20 nm show exposed low-index （111） ...Bimetallic PtxCuy nanocrystals （NCs） with well-defined hexa-pod morphology were synthesized via a wet chemistry approach. The as-synthesized convex NCs with dimensions of around 20 nm show exposed low-index （111） facets on the seeds and various high-index facets on the pods. The growth mechanism involved preferred growth along the 〈100〉 crystallographic direction on cuboctahedral seeds. The synthetic protocol could be applied to the synthesis of PtxCuy NCs with various Cu/Pt ratios. The electro-catalytic activity of the hexa-pod PtxCuy NCs supported on carbon black towards the oxygen reduction reaction （ORR） was studied. The hexa-pod PtCu2/C catalysts exhibit the highest specific activity （3.7 mA/cm^2pt） and mass activity （2.4 A/mget） reported to date for PtxCuy. Comparison with other morphological forms of PtxCuy indicated that the enhanced activity originated from morphological factors. The existence of high-index facets as well as abundant edges and steps on the pods could reasonably explain the enhanced catalytic activity. The hexa-pod PtxCuy/C catalysts also show high morphological stability and activity after accelerated durability tests. The as-synthesized hexa-pod PtxCuy NCs have high potential as cathode electro-catalysts for proton exchange membrane fuel cells.展开更多
基金This project is supported by National Center of New Drug Research,Science and Technology Committee and Educational Committee of Shanghai.
文摘Two new isoflavones (8, 3'-dihydroxy-7,4'-dimethoxyisoflavone, odoratin-7-0-[3-D-glu-copyranoside) and four known isoflavones (formononetin, 7,3'-dihydroxy-8,4'-dimethoxyisoflavone, calycosin, calycosin-7-0-(3-D-glucopyranoside) were isolated from the roots of Astragalus mem-branaceus (Fisch.) Bunge. Their structures were established by spectral analysis.
文摘An epidemiological survey of anisakid nematodes was conducted on 205 specimens of horse mackerel （Trachurus trachurus） and 183 of axillary seabream （Pagellus acarne） captured in the zone between Tangier and Larache in the north Atlantic Moroccan＇s coasts. Three species of nematodes were morphologically identified： Anisakis simplex s.l., Hysterothylacium sp., Pseudotarranova sp. According to the season, the nematode most observed in T. trachurus was .4. simplex s.1. （the highest values of prevalence （100%）, the mean intensity （48.6）. Hysterothylacium sp. was the most frequent anisakid in P. acarne with 100% of prevalence and 34.46 of the mean intensity. The infestation parameters were also analyzed according to the host species length, noting a maximum of infected fish by Anisakis simplex s.1. （96%） in samples of horse mackerel larger than 28 cm, while in axiliary seabream, the highest prevalence of infestation by Hysterothylacium sp. （100%） was found in fish more than 29 cm.
文摘We propose a theoretical model of a nanoemitter for giga- and terahertz-range waves. The model is based on a peapod structure comprising a carbon nanotube with chiral indices （10, 10）. Three encapsulated and partially polymerized fuUerene C60 molecules and a positively charged C60 fullerene are trapped inside the nanotube. The motion of the charged fullerene and the radiation frequency were controlled using an external electric field. Stable terahertz radiation at a frequency of 0.36 THz was produced at 300 K with an external electrical field of 10 V/μm. Stable radiation in the gigahertz range was observed at 50 K with an electric field below 10 V/m. A theoretical simulation was performed using the tight-binding molecular dynamics method with a description of the van der Waals interaction by the Morse potential. The system described by the theoretical model was experimentally observed.
基金We acknowledge the Microstructure Laboratory for Energy Materials （MLEM） at CUP for the technical support with TEM. We also acknowledge the funding support from the National Natural Science Foundation of China （No. 21303265）, Ph.D. Programs Foundation of Ministry of Education of China （No. 20130007120012） and Young Talent Award of CUP （No. YJRC-2013-46）.
文摘Bimetallic PtxCuy nanocrystals （NCs） with well-defined hexa-pod morphology were synthesized via a wet chemistry approach. The as-synthesized convex NCs with dimensions of around 20 nm show exposed low-index （111） facets on the seeds and various high-index facets on the pods. The growth mechanism involved preferred growth along the 〈100〉 crystallographic direction on cuboctahedral seeds. The synthetic protocol could be applied to the synthesis of PtxCuy NCs with various Cu/Pt ratios. The electro-catalytic activity of the hexa-pod PtxCuy NCs supported on carbon black towards the oxygen reduction reaction （ORR） was studied. The hexa-pod PtCu2/C catalysts exhibit the highest specific activity （3.7 mA/cm^2pt） and mass activity （2.4 A/mget） reported to date for PtxCuy. Comparison with other morphological forms of PtxCuy indicated that the enhanced activity originated from morphological factors. The existence of high-index facets as well as abundant edges and steps on the pods could reasonably explain the enhanced catalytic activity. The hexa-pod PtxCuy/C catalysts also show high morphological stability and activity after accelerated durability tests. The as-synthesized hexa-pod PtxCuy NCs have high potential as cathode electro-catalysts for proton exchange membrane fuel cells.
