A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameteriza...A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameterization scheme has improved the representation of physical processes in the existing land surface model.Numerical simulations using CCM3 with improved land-surface processes and with the original land-surface processes are compared against the NCEP reanalysis.It is found that the CCM3 version using the improved land surface model shows significant improvements in simulating precipitation in China during the summer season,the general circulation over East Asia,and wind fields over the Tibet Plateau.For the summer season,the improved model was able to better simulate the Indian summer monsoon components,including the mean northerly wind in the upper troposphere and mean southerly wind in the lower troposphere.展开更多
Poly( N isopropylacrylamide)/poly(vinyl alcohol)(PNV) hydrogels were prepared by repetitive freezing and thawing. This kind of hydrogels was formed through physical crosslinking, i.e. hydrogen bonds during the freezin...Poly( N isopropylacrylamide)/poly(vinyl alcohol)(PNV) hydrogels were prepared by repetitive freezing and thawing. This kind of hydrogels was formed through physical crosslinking, i.e. hydrogen bonds during the freezing process. The swelling ratio and deswelling/reswelling kinetics were measured gravimetrically and this novel hydrogel exhibits a temperature sensitivity. This hydrogel may be useful both in biomedical and biotechnological fields.展开更多
基金supported by Chinese National Science Foundation (NSFC) (No.40875050, 40575037, 40175020)National Key Basic Science Studies Developing Program of "973" (2007CB411506)
文摘A parameterization of soil freezing-thawing physics for use in the land-surface model of the National Center for Atmospheric Research(NCAR) Community Climate Model(CCM3) is developed and evaluated.The new parameterization scheme has improved the representation of physical processes in the existing land surface model.Numerical simulations using CCM3 with improved land-surface processes and with the original land-surface processes are compared against the NCEP reanalysis.It is found that the CCM3 version using the improved land surface model shows significant improvements in simulating precipitation in China during the summer season,the general circulation over East Asia,and wind fields over the Tibet Plateau.For the summer season,the improved model was able to better simulate the Indian summer monsoon components,including the mean northerly wind in the upper troposphere and mean southerly wind in the lower troposphere.
文摘Poly( N isopropylacrylamide)/poly(vinyl alcohol)(PNV) hydrogels were prepared by repetitive freezing and thawing. This kind of hydrogels was formed through physical crosslinking, i.e. hydrogen bonds during the freezing process. The swelling ratio and deswelling/reswelling kinetics were measured gravimetrically and this novel hydrogel exhibits a temperature sensitivity. This hydrogel may be useful both in biomedical and biotechnological fields.
