This study investigates the local air-sea relationship associated with the two dominant intraseasonal oscillation（ISO） components during the spring-to-summer transition and compares their properties using multiple a...This study investigates the local air-sea relationship associated with the two dominant intraseasonal oscillation（ISO） components during the spring-to-summer transition and compares their properties using multiple air-sea variables in the period 1998-2013.The amplitude of percentage variance in SST in periods of 10-20 and 30-60 days are comparable,but the locations of the maxima differ.A strong percentage variance in the 10-20-day SST is evident in the equatorial western Pacific,whereas for the 30-60-day SST the strongest ratio occurs in the North Indian Ocean（NIO）,South China Sea（SCS）,and North Pacific.Over the NIO,SCS,and Philippine Sea,there are significant correlations between SST and precipitation for both 10-20-day and 30-60-day ISOs.In contrast,the correlations between SST and surface heat fluxes cover a broader region and have larger coefficients.Thus,the atmospheric variables and surface heat fluxes show larger variations within the higher frequency band.However,the amplitude of the correlation coefficients between SST and surface heat fluxes,and SST and rainfall,is greater in the lower frequency band.The corresponding time lags for the different variables reveal that a strong local air-sea interaction is indicated over the NIO,SCS,and western North Pacific,from April to June in both timescales;however,the strength of the air-sea relationship depends on the region and variable.展开更多
Objective： To compare the volatile constituents in mugwort leaves produced in Qichun, Hubei Province and Nanyang, Henan Province. Methods： The volatile constituents were extracted using headspace heating and analyze...Objective： To compare the volatile constituents in mugwort leaves produced in Qichun, Hubei Province and Nanyang, Henan Province. Methods： The volatile constituents were extracted using headspace heating and analyzed using gas chromatography-mass spectrometry （GC-MS）. Then a qualitative analysis was made according to the standard database provided by the National Institute of Standards and Technology （NIST） and the relative contents of each constituent were calculated using the peak area normalization method. Results： A total of 59 compounds were identified from the mugwort leaves from Qichun and 51 compounds were identified from the mugwort leaves from Nanyang. These mainly include monoterpenoids, sesquiterpenoids, C^HvOz and other compounds involving the aldehyde, ketone, alkane and benzene. The mugwort leaves from Qichun and Nanyang share 32 common volatile constituents. The chromatographic peak area of identified compounds accounting for 96.38% of GC-MS total chromatographic peak areain Qichun mugwort leaves, versus 95.54% of that in Nanyang mugwort leaves. Conclusion： The headspace heating extraction combined with GC-MS technology can evidently display similarities and differences of volatile constituents in mugwort leaves produced in different areas and thus provide scientific basis for the quality and screening of mugwort leaves.展开更多
基金jointly supported by the National Basic Research Program of China[grant numbers 2014CB953902 and2015CB453202]the Strategic Leading Science Projects of the Chinese Academy of Sciences[grant number XDAl 1010402]the National Natural Science Foundation of China[grant numbers 41305065,41305068,and 91337216]
文摘This study investigates the local air-sea relationship associated with the two dominant intraseasonal oscillation（ISO） components during the spring-to-summer transition and compares their properties using multiple air-sea variables in the period 1998-2013.The amplitude of percentage variance in SST in periods of 10-20 and 30-60 days are comparable,but the locations of the maxima differ.A strong percentage variance in the 10-20-day SST is evident in the equatorial western Pacific,whereas for the 30-60-day SST the strongest ratio occurs in the North Indian Ocean（NIO）,South China Sea（SCS）,and North Pacific.Over the NIO,SCS,and Philippine Sea,there are significant correlations between SST and precipitation for both 10-20-day and 30-60-day ISOs.In contrast,the correlations between SST and surface heat fluxes cover a broader region and have larger coefficients.Thus,the atmospheric variables and surface heat fluxes show larger variations within the higher frequency band.However,the amplitude of the correlation coefficients between SST and surface heat fluxes,and SST and rainfall,is greater in the lower frequency band.The corresponding time lags for the different variables reveal that a strong local air-sea interaction is indicated over the NIO,SCS,and western North Pacific,from April to June in both timescales;however,the strength of the air-sea relationship depends on the region and variable.
基金supported by National Basic Research Program of China(973 Program,No.2015CB554506)~~
文摘Objective： To compare the volatile constituents in mugwort leaves produced in Qichun, Hubei Province and Nanyang, Henan Province. Methods： The volatile constituents were extracted using headspace heating and analyzed using gas chromatography-mass spectrometry （GC-MS）. Then a qualitative analysis was made according to the standard database provided by the National Institute of Standards and Technology （NIST） and the relative contents of each constituent were calculated using the peak area normalization method. Results： A total of 59 compounds were identified from the mugwort leaves from Qichun and 51 compounds were identified from the mugwort leaves from Nanyang. These mainly include monoterpenoids, sesquiterpenoids, C^HvOz and other compounds involving the aldehyde, ketone, alkane and benzene. The mugwort leaves from Qichun and Nanyang share 32 common volatile constituents. The chromatographic peak area of identified compounds accounting for 96.38% of GC-MS total chromatographic peak areain Qichun mugwort leaves, versus 95.54% of that in Nanyang mugwort leaves. Conclusion： The headspace heating extraction combined with GC-MS technology can evidently display similarities and differences of volatile constituents in mugwort leaves produced in different areas and thus provide scientific basis for the quality and screening of mugwort leaves.
