A new skeleton taxane diterpene,taxayuntin,was isolated from the leaves and stems of Taxus yunnanensis.Its structure was determined by spectroscopic methods(MS,~1H NMR,^(13)C NMR, ~1H-~1H COSY,~1H-^(13)C COSY and ^(13...A new skeleton taxane diterpene,taxayuntin,was isolated from the leaves and stems of Taxus yunnanensis.Its structure was determined by spectroscopic methods(MS,~1H NMR,^(13)C NMR, ~1H-~1H COSY,~1H-^(13)C COSY and ^(13)C-~1H COLOC)and X-ray diffraction.展开更多
a new triterpene compound was isolated from the stems and leaves of Panax ginseng C. A. Meyer and established as 3β, 6α, 12β-trihydroxy-dammar-20(21), 24-diene-6-0-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside o...a new triterpene compound was isolated from the stems and leaves of Panax ginseng C. A. Meyer and established as 3β, 6α, 12β-trihydroxy-dammar-20(21), 24-diene-6-0-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside on the basis of spectral analysis and chemical evidence.展开更多
How long should paid maternity leave be？ Three months？ Six months？ A year？ Or three whole years？ Though Chinese laws and regulations allow 98 days of maternity leave, Zhang Lihui, a member of the 12th National C...How long should paid maternity leave be？ Three months？ Six months？ A year？ Or three whole years？ Though Chinese laws and regulations allow 98 days of maternity leave, Zhang Lihui, a member of the 12th National Committee of the Chinese People＇s Political Consultative Conference, suggested that the entitlement be increased to three years, until the newborns are old enough to be sent to kindergarten. According to Zhang, this would not only meet the psychological and educational needs of children, but also help mothers work more efficiently in the future as they do not need to worry too much about their children.展开更多
Modern palms are diverse and widespread in the tropics and subtropics,especially the tropical rainforests.However,most fossil palm records have been reported from regions of relatively higher latitude.In this paper se...Modern palms are diverse and widespread in the tropics and subtropics,especially the tropical rainforests.However,most fossil palm records have been reported from regions of relatively higher latitude.In this paper seven species of coryphoid palm from the Eocene Changchang Basin of Hainan Island of South China are reported.These are Sabalites asymmetricus sp.nov.,S.robustus sp.nov.,S.tenufolius sp.nov.,S.szei Guo,S.changchagnensis Guo,Livistona sp.,and Amesoneuron sp.According to leaf morphological characteristics,they can be classified as members of the subfamily Coryphoideae.In extant flora of Hainan Island,only three species of Livistona have costapalmate leaves.These palm fossils indicate that,during the Eocene,flora in Hainan Island included a diversity of coryphoid palms,which have some bearings on the reconstruction of the palaeoclimate of South China.展开更多
文摘A new skeleton taxane diterpene,taxayuntin,was isolated from the leaves and stems of Taxus yunnanensis.Its structure was determined by spectroscopic methods(MS,~1H NMR,^(13)C NMR, ~1H-~1H COSY,~1H-^(13)C COSY and ^(13)C-~1H COLOC)and X-ray diffraction.
文摘a new triterpene compound was isolated from the stems and leaves of Panax ginseng C. A. Meyer and established as 3β, 6α, 12β-trihydroxy-dammar-20(21), 24-diene-6-0-α-L-rhamnopyranosyl-(1→2)-β-D-glucopyranoside on the basis of spectral analysis and chemical evidence.
文摘How long should paid maternity leave be？ Three months？ Six months？ A year？ Or three whole years？ Though Chinese laws and regulations allow 98 days of maternity leave, Zhang Lihui, a member of the 12th National Committee of the Chinese People＇s Political Consultative Conference, suggested that the entitlement be increased to three years, until the newborns are old enough to be sent to kindergarten. According to Zhang, this would not only meet the psychological and educational needs of children, but also help mothers work more efficiently in the future as they do not need to worry too much about their children.
基金supported by National Natural Science Foundation of China(Grant Nos.41210001,31070200and40972011)National Basic Research Program of China(Grant No.2012CB822003)+2 种基金State Key Laboratory of Palaeobiology and Stratigraphy(Nanjing Institute of Geology and Palaeontology,CAS)(Grant No.123110)Fundamental Research Funds for the Central Universities(Grant No.12LGJC04)Key Project of Sun Yat-sen University for inviting foreign teachers and the Scientific Research Fund,Hongda Zhang,Sun Yat-sen University
文摘Modern palms are diverse and widespread in the tropics and subtropics,especially the tropical rainforests.However,most fossil palm records have been reported from regions of relatively higher latitude.In this paper seven species of coryphoid palm from the Eocene Changchang Basin of Hainan Island of South China are reported.These are Sabalites asymmetricus sp.nov.,S.robustus sp.nov.,S.tenufolius sp.nov.,S.szei Guo,S.changchagnensis Guo,Livistona sp.,and Amesoneuron sp.According to leaf morphological characteristics,they can be classified as members of the subfamily Coryphoideae.In extant flora of Hainan Island,only three species of Livistona have costapalmate leaves.These palm fossils indicate that,during the Eocene,flora in Hainan Island included a diversity of coryphoid palms,which have some bearings on the reconstruction of the palaeoclimate of South China.
