This study aimed to develop a water-extraction system which could produce the fresh water from the air in arid regions and which used renewable energies as the electric power source. In this paper, the experiments for...This study aimed to develop a water-extraction system which could produce the fresh water from the air in arid regions and which used renewable energies as the electric power source. In this paper, the experiments for water extraction from the air were carried out by using the novel multi-stage water-extraction device with Peltier deices for two cases of temperature and related humidity of the air. One was the case where the temperature and the related humidity of the air were constant, and the other was the case where they were simulated the variation of the temperature and related humidity of the air in a day of summer and spring in Loess Plateau, China. The effects of the temperature and related humidity of the atmospheric air and supply the electric power to Peltier devices on performance of water production of the device were investigated and reported.展开更多
Carbohydrate represents an important part of the soil labile organic carbon pool. Water soluble carbohydrate drives the C cycle in forest soil by affecting microbial activity and hot water extractable car- bohydrate i...Carbohydrate represents an important part of the soil labile organic carbon pool. Water soluble carbohydrate drives the C cycle in forest soil by affecting microbial activity and hot water extractable car- bohydrate is thought related to soil carbon sequestration due to the asso- ciation with soil aggregation. In a temperate forest region of northeast China, Changbai Mountain, we investigated the abundance, spatial dis- tribution, and seasonal dynamics of cool and hot-water extractable car- bohydrate in soils under mixed broad-leaved Korean pine forest. The concentrations of cool-water extractable carbohydrate （CWECH） in three soil layers （0-5, 5-10, 10-20 cm） ranged from 4.1 to 193.3 g.kg-1 dry soil, decreasing rapidly with soil depth. On an annual average, the CWECH concentrations in soils at depths of 5-10 and 10-20 cm were 54.2% and 24.0%, respectively, of that in the 0-5 cm soil layer. CWECH showed distinct seasonal dynamics with the highest concentrations in early spring, lowest in summer, and increasing concentrations in autumn. Hot-water extractable carbohydrate （HWECH） concentrations in three soil layers ranged from 121.4 to 2026.2 g.kgq dry soil, which were about one order of magnitude higher than CWECH. The abundance of HWECH was even more profile-dependent than CWECH, and decreased more rapidly with soil depth. On an annual average, the HWECH concentration in soils 10-20 cm deep was about one order of magnitude lower than that in the top 0-5 cm soil. The seasonality of HWECH roughly tracked that of CWECH but with seasonal fluctuations of smaller amplitude. The car- bohydrate concentrations in cool/hot water extracts of soil were positively correlated with UV254 and UV2s0 of the same solution, which has implications for predicting the leaching loss of water soluble organic carbon.展开更多
增强归一化差异水体指数(augmented normalized difference water index,ANDWI)是一种新颖、稳健的水体指数,但在某些情况下ANDWI可能对表面聚集型水华的水体提取效果较差;因此,本文依据水体指数ANDWI的特点及富营养化水体指数(improved...增强归一化差异水体指数(augmented normalized difference water index,ANDWI)是一种新颖、稳健的水体指数,但在某些情况下ANDWI可能对表面聚集型水华的水体提取效果较差;因此,本文依据水体指数ANDWI的特点及富营养化水体指数(improved eutrophic water body index,MEWI)的构建思路,基于富营养化水体等地物的光谱特性,构造了修正的增强归一化差异水体指数(modified augmented normalized difference water index,MANDWI)。本文以不同季节、不同水华等级的太湖进行水体提取验证,将MANDWI与双红外水体指数(double infrared band water index,DIBWI)、MEWI、多波段组合水体指数(multi-band combination water index,MBCWI)和ANDWI进行对比,结果表明MANDWI适用于不同季节且具有较好的水体提取效果,随着水华等级提升,MADNWI仍具有较高的水体提取精度(总体精度为0.99,Kappa系数为0.98),而其他水体指数的提取效果较差。MANDWI的提出增强了遥感水体提取能力,对于水资源管理和保护具有重要意义,同时也为类似水体指数的构建提供参考。展开更多
文摘This study aimed to develop a water-extraction system which could produce the fresh water from the air in arid regions and which used renewable energies as the electric power source. In this paper, the experiments for water extraction from the air were carried out by using the novel multi-stage water-extraction device with Peltier deices for two cases of temperature and related humidity of the air. One was the case where the temperature and the related humidity of the air were constant, and the other was the case where they were simulated the variation of the temperature and related humidity of the air in a day of summer and spring in Loess Plateau, China. The effects of the temperature and related humidity of the atmospheric air and supply the electric power to Peltier devices on performance of water production of the device were investigated and reported.
基金supported by made possible through National Key Basic Research Foundation, China (grants 2011CB403202)the National Natural Science Foundation of China (40930107)Program for Changjiang Scholars and Innovative Research Team in University (IRT1054)
文摘Carbohydrate represents an important part of the soil labile organic carbon pool. Water soluble carbohydrate drives the C cycle in forest soil by affecting microbial activity and hot water extractable car- bohydrate is thought related to soil carbon sequestration due to the asso- ciation with soil aggregation. In a temperate forest region of northeast China, Changbai Mountain, we investigated the abundance, spatial dis- tribution, and seasonal dynamics of cool and hot-water extractable car- bohydrate in soils under mixed broad-leaved Korean pine forest. The concentrations of cool-water extractable carbohydrate （CWECH） in three soil layers （0-5, 5-10, 10-20 cm） ranged from 4.1 to 193.3 g.kg-1 dry soil, decreasing rapidly with soil depth. On an annual average, the CWECH concentrations in soils at depths of 5-10 and 10-20 cm were 54.2% and 24.0%, respectively, of that in the 0-5 cm soil layer. CWECH showed distinct seasonal dynamics with the highest concentrations in early spring, lowest in summer, and increasing concentrations in autumn. Hot-water extractable carbohydrate （HWECH） concentrations in three soil layers ranged from 121.4 to 2026.2 g.kgq dry soil, which were about one order of magnitude higher than CWECH. The abundance of HWECH was even more profile-dependent than CWECH, and decreased more rapidly with soil depth. On an annual average, the HWECH concentration in soils 10-20 cm deep was about one order of magnitude lower than that in the top 0-5 cm soil. The seasonality of HWECH roughly tracked that of CWECH but with seasonal fluctuations of smaller amplitude. The car- bohydrate concentrations in cool/hot water extracts of soil were positively correlated with UV254 and UV2s0 of the same solution, which has implications for predicting the leaching loss of water soluble organic carbon.
文摘增强归一化差异水体指数(augmented normalized difference water index,ANDWI)是一种新颖、稳健的水体指数,但在某些情况下ANDWI可能对表面聚集型水华的水体提取效果较差;因此,本文依据水体指数ANDWI的特点及富营养化水体指数(improved eutrophic water body index,MEWI)的构建思路,基于富营养化水体等地物的光谱特性,构造了修正的增强归一化差异水体指数(modified augmented normalized difference water index,MANDWI)。本文以不同季节、不同水华等级的太湖进行水体提取验证,将MANDWI与双红外水体指数(double infrared band water index,DIBWI)、MEWI、多波段组合水体指数(multi-band combination water index,MBCWI)和ANDWI进行对比,结果表明MANDWI适用于不同季节且具有较好的水体提取效果,随着水华等级提升,MADNWI仍具有较高的水体提取精度(总体精度为0.99,Kappa系数为0.98),而其他水体指数的提取效果较差。MANDWI的提出增强了遥感水体提取能力,对于水资源管理和保护具有重要意义,同时也为类似水体指数的构建提供参考。
