基于密度泛函理论,本文利用分子动力学模拟软件Material studio 8.0,对煤焦油化学链气化裂解产生的CO、CO_2、C、H_2、CH_4等产物和过剩载氧体发生的二次反应进行研究,并对Fe_2O_3与CO、H_2、CH_4气相产物的反应势垒进行比较。研究结果...基于密度泛函理论,本文利用分子动力学模拟软件Material studio 8.0,对煤焦油化学链气化裂解产生的CO、CO_2、C、H_2、CH_4等产物和过剩载氧体发生的二次反应进行研究,并对Fe_2O_3与CO、H_2、CH_4气相产物的反应势垒进行比较。研究结果表明,在温度相同时,铁基载氧体与H_2最先发生反应,反应势垒最低,与CO反应势垒次之,而载氧体与CH_4之间较难发生反应。在煤焦油化学链气化反应器末端,应采取措施避免CO和H_2与载氧体发生二次反应。该研究对提高化学链气化效率具有指导意义。展开更多
The estimation of surface evapotranspiration （ET） with satellite dataset is one of the main subjects in the understanding of climate change, disaster monitoring and the circulation of water vapor and energy in Tibet...The estimation of surface evapotranspiration （ET） with satellite dataset is one of the main subjects in the understanding of climate change, disaster monitoring and the circulation of water vapor and energy in Tibet Autonomous Region （TAR）. This research selects satellite images on January 11, April 6, July 31 and October 19 in 2010 as the representative of winter, spring, summer and autumn respectively, estimates the distribution of daily surface ET based on the surface energy balance system （SEBS） along with potential evapotranspiration （PET） and ET derived from Penman-Monteith （P-M） method. The results are obtained as follows. （1） The seasonal distribution of ET and PET basically decreases from the southeast part to the northwest part of TAR. Although ET and PET have similar spatial distributions, there are still some differences to estimate the extreme values especially the maximum value in the middle and southeastern parts of TAR. No matter what kind of methods we adopted, the maximum value of ET and PET always appears in summer, followed by autumn or spring while that in winter is the smallest. （2） In order to better understand the accuracy of SEBS model in the estimation of ET, we compared the ET from SEBS and the ET obtained from P-M method. Results show that the ET from SEBS could estimates the variation trend of actual ET, but it slightly underestimates or overestimates the value of ET as a whole, especially for those areas with thick forest. （3） The spatial distribution of Normalized Difference Vegetation Index （NDVI） exhibits a decreasing trend from the southeast part to the northwest part of TAR which displays remarkable consistency of distributions between ET and vegetation index. ET is well positively related to NDVI, minimum, mean, maximum air temperature and sunshine duration in different seasons while negatively related to precipitation, relative humidity and wind speed in summer.展开更多
文摘基于密度泛函理论,本文利用分子动力学模拟软件Material studio 8.0,对煤焦油化学链气化裂解产生的CO、CO_2、C、H_2、CH_4等产物和过剩载氧体发生的二次反应进行研究,并对Fe_2O_3与CO、H_2、CH_4气相产物的反应势垒进行比较。研究结果表明,在温度相同时,铁基载氧体与H_2最先发生反应,反应势垒最低,与CO反应势垒次之,而载氧体与CH_4之间较难发生反应。在煤焦油化学链气化反应器末端,应采取措施避免CO和H_2与载氧体发生二次反应。该研究对提高化学链气化效率具有指导意义。
基金National Natural Science Foundation of China, No.41130960 No.41165011+2 种基金 Public Project of Meteorology, No.GYHy201006054 Major projects in Gansu Province, No. 1001JKA001 Project of the China Meteoro- logical Administration, No.CMAGJ2013M51
文摘The estimation of surface evapotranspiration （ET） with satellite dataset is one of the main subjects in the understanding of climate change, disaster monitoring and the circulation of water vapor and energy in Tibet Autonomous Region （TAR）. This research selects satellite images on January 11, April 6, July 31 and October 19 in 2010 as the representative of winter, spring, summer and autumn respectively, estimates the distribution of daily surface ET based on the surface energy balance system （SEBS） along with potential evapotranspiration （PET） and ET derived from Penman-Monteith （P-M） method. The results are obtained as follows. （1） The seasonal distribution of ET and PET basically decreases from the southeast part to the northwest part of TAR. Although ET and PET have similar spatial distributions, there are still some differences to estimate the extreme values especially the maximum value in the middle and southeastern parts of TAR. No matter what kind of methods we adopted, the maximum value of ET and PET always appears in summer, followed by autumn or spring while that in winter is the smallest. （2） In order to better understand the accuracy of SEBS model in the estimation of ET, we compared the ET from SEBS and the ET obtained from P-M method. Results show that the ET from SEBS could estimates the variation trend of actual ET, but it slightly underestimates or overestimates the value of ET as a whole, especially for those areas with thick forest. （3） The spatial distribution of Normalized Difference Vegetation Index （NDVI） exhibits a decreasing trend from the southeast part to the northwest part of TAR which displays remarkable consistency of distributions between ET and vegetation index. ET is well positively related to NDVI, minimum, mean, maximum air temperature and sunshine duration in different seasons while negatively related to precipitation, relative humidity and wind speed in summer.
