The cold vortex is a major high impact weather system in northeast China during the warm season, its frequent activities also affect the short-term climate throughout eastern China. How to objectively and quantitative...The cold vortex is a major high impact weather system in northeast China during the warm season, its frequent activities also affect the short-term climate throughout eastern China. How to objectively and quantitatively predict the intensity trend of the cold vortex is an urgent and difficult problem for current short-term climate prediction. Based on the dynamical-statistical combining principle, the predicted results of the Beijing Climate Center＇s global atmosphereocean coupled model and rich historical data are used for dynamic-statistical extra-seasonal prediction testing and actual prediction of the summer 500-hPa geopotential height over the cold vortex activity area. The results show that this method can significantly reduce the model＇s prediction error over the cold vortex activity area, and improve the prediction skills. Furthermore, the results of the sensitivity test reveal that the predicted results are highly dependent on the quantity of similar factors and the number of similar years.展开更多
A series of pyrrolopyrazinone-chalcone hybrids（12a-12q） was designed,synthesized and screened for their antitumor activity against SKOV-3,A549 and HeLa cell lines in vitro.Compared with the pyrrolopyrazinone（10a） ...A series of pyrrolopyrazinone-chalcone hybrids（12a-12q） was designed,synthesized and screened for their antitumor activity against SKOV-3,A549 and HeLa cell lines in vitro.Compared with the pyrrolopyrazinone（10a） and 5-fluorouracil（5-FU）,nearly all the tested compounds showed significantly-improved antitumor activities.The most promising compounds 12e and 12k（IC50=0.25 and 0.88 μmol/L） respectively show activities of 123and 35 times that of compound 10a（IC50=30.74 μmol/L） against HeLa cell line.The result reveals that the presence of chalcone moiety is beneficial to their activity and selectivity.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.41375078)the National Basic Research Program of China(Grant Nos.2012CB955902 and 2013CB430204)the Special Scientific Research Fund of Public Welfare Profession of China(Grant No.GYHY201306021)
文摘The cold vortex is a major high impact weather system in northeast China during the warm season, its frequent activities also affect the short-term climate throughout eastern China. How to objectively and quantitatively predict the intensity trend of the cold vortex is an urgent and difficult problem for current short-term climate prediction. Based on the dynamical-statistical combining principle, the predicted results of the Beijing Climate Center＇s global atmosphereocean coupled model and rich historical data are used for dynamic-statistical extra-seasonal prediction testing and actual prediction of the summer 500-hPa geopotential height over the cold vortex activity area. The results show that this method can significantly reduce the model＇s prediction error over the cold vortex activity area, and improve the prediction skills. Furthermore, the results of the sensitivity test reveal that the predicted results are highly dependent on the quantity of similar factors and the number of similar years.
文摘A series of pyrrolopyrazinone-chalcone hybrids（12a-12q） was designed,synthesized and screened for their antitumor activity against SKOV-3,A549 and HeLa cell lines in vitro.Compared with the pyrrolopyrazinone（10a） and 5-fluorouracil（5-FU）,nearly all the tested compounds showed significantly-improved antitumor activities.The most promising compounds 12e and 12k（IC50=0.25 and 0.88 μmol/L） respectively show activities of 123and 35 times that of compound 10a（IC50=30.74 μmol/L） against HeLa cell line.The result reveals that the presence of chalcone moiety is beneficial to their activity and selectivity.
