The humidity effect, namely the markedly positive correlation between the stable isotopic ratio in precipitation and the dew-point deficit ATd in the atmosphere, is put forward firstly and the relationships between t...The humidity effect, namely the markedly positive correlation between the stable isotopic ratio in precipitation and the dew-point deficit ATd in the atmosphere, is put forward firstly and the relationships between the δ18O in precipitation and ATd are analyzed for the Urumqi and Kunming stations, which have completely different climatic characteristics. Although the seasonal variations in δ18O and △Td exhibit differences between the two stations, their humidity effect is notable. The correlation coefficient and its confidence level of the humidity effect are higher than those of the amount effect at Kunming, showing the marked influence of the humidity conditions in the atmosphere on stable isotopes in precipitation. Using a kinetic model for stable isotopic fractionation, and according to the seasonal distribution of mean monthly temperature at 500 hPa at Kunming, the variations of the δ18O in condensate in cloud are simulated. A very good agreement between the seasonal variations of the simulated mean δ18O and the mean monthly temperature at 500 hPa is obtained, showing that the oxygen stable isotope in condensate of cloud experiences a temperature effect. Such a result is markedly different from the amount effect at the ground. Based on the simulations of seasonal variations of δ18O in falling raindrops, it can be found that, in the dry season from November to April, the increasing trend with falling distance of δ18O in falling raindrops corresponds remarkably to the great △Td, showing a strong evaporation enrichment function in falling raindrops; however, in the wet season from May to October, the δ18O in falling raindrops displays an unapparent increase corresponding to the small △Td, except in May. By comparing the simulated mean δ18O at the ground with the actual monthly δ18O in precipitation, we see distinctly that the two monthly δ18O variations agree very well. On average, the δ18O values are relatively lower because of the highly moist air, heavy rainfall, small ATd and weak evaporati展开更多
Polypyrrole (PPy) powder was synthesized by chemical polymerization at 0℃under atmospheric condition and its layer was prepared by dip coating method on the alumina substrate with interdigitated electrodes.The influ...Polypyrrole (PPy) powder was synthesized by chemical polymerization at 0℃under atmospheric condition and its layer was prepared by dip coating method on the alumina substrate with interdigitated electrodes.The influence of relative humidity (RH 0～70%) to PPy sensor was studied.The measuring temperature was fixed at 25℃.Methanol and benzene were used as target gases.Various analytic techniques were examined to observe changes in the properties of PPy sensor.The sensitivity of PPy sensor to water vapor was linearly increased with the increasing humidity.As the relative humidity increase from 0% to 70%,the sensitivities to methanol and benzene vapor were reduced,and reduction ratio of sensitivity was 94%, 92.5% at RH 70%,respectively.展开更多
In this article, regularity of the global attractor for atmospheric circulation equations with humidity effect is considered. It is proved that atmospheric circulation equations with humidity effect possess a global a...In this article, regularity of the global attractor for atmospheric circulation equations with humidity effect is considered. It is proved that atmospheric circulation equations with humidity effect possess a global attractor in H^k(?, R^4) for any k≥0, which attracts any bounded set of H^k(Ω, R^4) in the H^k-norm. The result is established by means of an iteration technique and regularity estimates for the linear semigroup of operator, together with a classical existence theorem of global attractor.展开更多
基金This work was supported by the National Natural Science Foundation of China(Grant Nos.90302006 and 40271025)the National High Technology Research and Development Program of China(863 Program,Grant No.2002AA 135360)the Program of the Education Department of Hunan Province(Grant No.03C210).
文摘The humidity effect, namely the markedly positive correlation between the stable isotopic ratio in precipitation and the dew-point deficit ATd in the atmosphere, is put forward firstly and the relationships between the δ18O in precipitation and ATd are analyzed for the Urumqi and Kunming stations, which have completely different climatic characteristics. Although the seasonal variations in δ18O and △Td exhibit differences between the two stations, their humidity effect is notable. The correlation coefficient and its confidence level of the humidity effect are higher than those of the amount effect at Kunming, showing the marked influence of the humidity conditions in the atmosphere on stable isotopes in precipitation. Using a kinetic model for stable isotopic fractionation, and according to the seasonal distribution of mean monthly temperature at 500 hPa at Kunming, the variations of the δ18O in condensate in cloud are simulated. A very good agreement between the seasonal variations of the simulated mean δ18O and the mean monthly temperature at 500 hPa is obtained, showing that the oxygen stable isotope in condensate of cloud experiences a temperature effect. Such a result is markedly different from the amount effect at the ground. Based on the simulations of seasonal variations of δ18O in falling raindrops, it can be found that, in the dry season from November to April, the increasing trend with falling distance of δ18O in falling raindrops corresponds remarkably to the great △Td, showing a strong evaporation enrichment function in falling raindrops; however, in the wet season from May to October, the δ18O in falling raindrops displays an unapparent increase corresponding to the small △Td, except in May. By comparing the simulated mean δ18O at the ground with the actual monthly δ18O in precipitation, we see distinctly that the two monthly δ18O variations agree very well. On average, the δ18O values are relatively lower because of the highly moist air, heavy rainfall, small ATd and weak evaporati
文摘Polypyrrole (PPy) powder was synthesized by chemical polymerization at 0℃under atmospheric condition and its layer was prepared by dip coating method on the alumina substrate with interdigitated electrodes.The influence of relative humidity (RH 0～70%) to PPy sensor was studied.The measuring temperature was fixed at 25℃.Methanol and benzene were used as target gases.Various analytic techniques were examined to observe changes in the properties of PPy sensor.The sensitivity of PPy sensor to water vapor was linearly increased with the increasing humidity.As the relative humidity increase from 0% to 70%,the sensitivities to methanol and benzene vapor were reduced,and reduction ratio of sensitivity was 94%, 92.5% at RH 70%,respectively.
基金Supported by the National Natural Science Foundation of China(No.11701399)
文摘In this article, regularity of the global attractor for atmospheric circulation equations with humidity effect is considered. It is proved that atmospheric circulation equations with humidity effect possess a global attractor in H^k(?, R^4) for any k≥0, which attracts any bounded set of H^k(Ω, R^4) in the H^k-norm. The result is established by means of an iteration technique and regularity estimates for the linear semigroup of operator, together with a classical existence theorem of global attractor.
