Evapotranspiration （ET） process of plants is controlled by several factors. Besides the physiological factors of plants, height, density, LAI （leaf area index）, etc., the change of meteorological factors, such as ...Evapotranspiration （ET） process of plants is controlled by several factors. Besides the physiological factors of plants, height, density, LAI （leaf area index）, etc., the change of meteorological factors, such as radiation, temperature, wind and precipitation, can influence ET process evidently, thus remodeling the spatial and temporal distribution of ET. In order to illuminate the effects of meteorological factors on wetland ET, the ET of Zhalong Wetland was calculated from 1961 to 2000, the statistical relationships （models） between ET and maximum temperature （Tmax）, minimum temperature （Tmin）, precipitation （P） and wind speed at 2m height （U2） were established, and the sensitivity analysis of the variables in the model was performed. The results show that Tmax and Tmin are two dominating factors that influence ET markedly, and the difference of rising rate between Tmax and Tmin determines the change trend of ET. With the climatic scenarios of four General Circulation Models （GCMs）, the ET from 2001 to 2060 was predicted by the statistical model. Compared to the period of 1961-2000, the water consumption by ET will increase greatly in the future. According to the scenarios, the rise of Tmax （about 1.5℃ to 3.3℃） and Tmin （about 1.7℃ to 3.5℃） will cause an additional water consumotion of 14.0%- 17.8% for reed swami）. The ecological water demand in Zhalong Wetland will become more severe.展开更多
Taking the flood resources utilization in Baicheng,Jilin during 2002–2007 as the research background,and based on the entropy weight and multi-level&multi-objective fuzzy optimization theory,this research establi...Taking the flood resources utilization in Baicheng,Jilin during 2002–2007 as the research background,and based on the entropy weight and multi-level&multi-objective fuzzy optimization theory,this research established a multi-level&semi-constructive index system and dynamic successive evaluation model for comprehensive benefit evaluation of regional flood resources utilization.With the year 2002 as the base year,the analyzing results showed that there existed a close positive correlation between flood utilization volume and its benefits,comprehensive evaluation value and its comparison increment.Within the six successive evaluation years,the comprehensive benefit of 2003 was the best,in which the benefit evaluation increment reached 82.8%whereas the year of 2004 was the worst,in which the increment was only 18.2%.Thus the sustainability and correctness of the evaluation were verified by six years successive evaluation and increment comparison.The analyzing results showed that the economic benefits,ecological benefits and social benefits of flood utilization were remarkable,and that the comprehensive benefit could be improved by increasing flood utilization capacity,which would promote the regional sustainable development as well.The established dynamic successive evaluation provides a stable theoretical basis and technical support for further flood utilization.展开更多
A series of ice freezing-thawing experiments are performed under different nitro- benzene concentrations of 1.7, 8, 17, 170, and 1700 μg/L. A special flume, made of stainless steel and glass, is built to simulate the...A series of ice freezing-thawing experiments are performed under different nitro- benzene concentrations of 1.7, 8, 17, 170, and 1700 μg/L. A special flume, made of stainless steel and glass, is built to simulate the flowing water for the experiments. The ice frozen in cold room has similar crystal structure of natural ice, therefore the behaviors of nitrobenzene in the ice frozen in cold room is also believed to be similar to that in natural ice. The results of the experiments reveal that the freezing rate of ice decreases with the increase of nitrobenzene concentration in water, and that the nitrobenzene ratio in water-ice system becomes higher with the increase of freezing rate. In addition, the nitrobenzene in ice does not move and is only re- leased into water after melt.展开更多
基金Under the auspices of the National Natural Science Foundation of China (No. 50139020)
文摘Evapotranspiration （ET） process of plants is controlled by several factors. Besides the physiological factors of plants, height, density, LAI （leaf area index）, etc., the change of meteorological factors, such as radiation, temperature, wind and precipitation, can influence ET process evidently, thus remodeling the spatial and temporal distribution of ET. In order to illuminate the effects of meteorological factors on wetland ET, the ET of Zhalong Wetland was calculated from 1961 to 2000, the statistical relationships （models） between ET and maximum temperature （Tmax）, minimum temperature （Tmin）, precipitation （P） and wind speed at 2m height （U2） were established, and the sensitivity analysis of the variables in the model was performed. The results show that Tmax and Tmin are two dominating factors that influence ET markedly, and the difference of rising rate between Tmax and Tmin determines the change trend of ET. With the climatic scenarios of four General Circulation Models （GCMs）, the ET from 2001 to 2060 was predicted by the statistical model. Compared to the period of 1961-2000, the water consumption by ET will increase greatly in the future. According to the scenarios, the rise of Tmax （about 1.5℃ to 3.3℃） and Tmin （about 1.7℃ to 3.5℃） will cause an additional water consumotion of 14.0%- 17.8% for reed swami）. The ecological water demand in Zhalong Wetland will become more severe.
基金supported by the National Natural Science Foundation of China(Grant No.50679012)National Key Technologies Research and Development Program of China(Grant No.2006BAB14B05)
文摘Taking the flood resources utilization in Baicheng,Jilin during 2002–2007 as the research background,and based on the entropy weight and multi-level&multi-objective fuzzy optimization theory,this research established a multi-level&semi-constructive index system and dynamic successive evaluation model for comprehensive benefit evaluation of regional flood resources utilization.With the year 2002 as the base year,the analyzing results showed that there existed a close positive correlation between flood utilization volume and its benefits,comprehensive evaluation value and its comparison increment.Within the six successive evaluation years,the comprehensive benefit of 2003 was the best,in which the benefit evaluation increment reached 82.8%whereas the year of 2004 was the worst,in which the increment was only 18.2%.Thus the sustainability and correctness of the evaluation were verified by six years successive evaluation and increment comparison.The analyzing results showed that the economic benefits,ecological benefits and social benefits of flood utilization were remarkable,and that the comprehensive benefit could be improved by increasing flood utilization capacity,which would promote the regional sustainable development as well.The established dynamic successive evaluation provides a stable theoretical basis and technical support for further flood utilization.
基金Changjiang River Scholar and Innovative Team Developing Plan (Grant No. IRT0420) the National Natural Science Foundation of China (Grant No. 40676001)
文摘A series of ice freezing-thawing experiments are performed under different nitro- benzene concentrations of 1.7, 8, 17, 170, and 1700 μg/L. A special flume, made of stainless steel and glass, is built to simulate the flowing water for the experiments. The ice frozen in cold room has similar crystal structure of natural ice, therefore the behaviors of nitrobenzene in the ice frozen in cold room is also believed to be similar to that in natural ice. The results of the experiments reveal that the freezing rate of ice decreases with the increase of nitrobenzene concentration in water, and that the nitrobenzene ratio in water-ice system becomes higher with the increase of freezing rate. In addition, the nitrobenzene in ice does not move and is only re- leased into water after melt.
