稳态、饱和条件下,以速度v=0.214 cm min-1和0.470 cm min-1进行混合置换实验,研究大肠杆菌在砂质壤土中的运移,并根据平衡与非平衡假设下,对流-弥散方程数学模型进行数值模拟。结果表明,含非平衡的双点吸附、且含有不可逆滞留项的模型...稳态、饱和条件下,以速度v=0.214 cm min-1和0.470 cm min-1进行混合置换实验,研究大肠杆菌在砂质壤土中的运移,并根据平衡与非平衡假设下,对流-弥散方程数学模型进行数值模拟。结果表明,含非平衡的双点吸附、且含有不可逆滞留项的模型能够较好地模拟大肠杆菌在砂质壤土中的运移。模拟和实验结果均表明,大肠杆菌的BTC(Breakthrough Curve穿透曲线)与示踪剂相比峰值明显降低,拖尾明显,且出现延迟,总的流出量也明显少于示踪剂;当水流速度由0.214 cm min-1增至0.470 cm min-1时,大肠杆菌BTC峰值由0.05增至0.2,且随速度的增加,滞留系数减小。展开更多
[Objective]The aim was to research water retention of superabsorbent polymer （SAP） in sandy soils. [Method] With soils from an ancient course in the Yel ow River as materials, acrylate SAP was taken as water retenti...[Objective]The aim was to research water retention of superabsorbent polymer （SAP） in sandy soils. [Method] With soils from an ancient course in the Yel ow River as materials, acrylate SAP was taken as water retention materials to conduct the test. [Result] With 0.2%-0.4% SAP added, dewatering period of sandy soil extended after irrigation; the period of water retention quantity over 10% last for 42 d, which was significantly more than that of the control group in 16 d （saturated water reducing to 10%）; water retention effect proved better at the 2nd irrigation without soil stirring compared with the 1st irrigation. [Conclusion] The mixture of SAP with sandy soils promotes water retention in soils.展开更多
[Objective] To study the soil texture, water storage and related spectral characteristics of composited soil. [Method] 3 different ratios of composited soils was designed by using feldspathic sandstone and sand by 3 d...[Objective] To study the soil texture, water storage and related spectral characteristics of composited soil. [Method] 3 different ratios of composited soils was designed by using feldspathic sandstone and sand by 3 different ratios, 1：1（C1）, 1：2（C2） and 1：5（C3）, and the CK used loess soil and sand by 1：2, then the soil texture, water storage, soil and winter wheat spectral characteristic were measured and analyzed under those treatments in 2010-2013. [Result] （1） With the increasing of the plant- ing year, treatment C1, C2 and C3 all showed decreasing in the proportions of sand and increasing of silt and the CK showed decreasing of clay and increasing of sand, along 1-30 cm soil depth. Treatment C2 showed the proportion of sand, silt and clay were 76.69%, 18.72% and 4.70%, respectively. （2） The water contents of all the treatments were significant different from other in 0-60 cm soil depth, and showed increasing trend with the increasing of sand proportion. Treatment C2 had higher average water content during the 3 years than treatment CK, C1 and C3 by 21.34%, 11.59% and 3.91% in the same soil depth, respectively. （3） In 2013, the spectral reflection curve characters were similar for all treatment of winter wheat at the jointing stage and filling stage along the full-wave band （350-2 500 nm）, and the reflectance was higher in the jointing stage than the filling stage; the reflection peak was found around 550 nm, a part of green light wave band. Treatment C2 showed the highest canopy that all treatments had similar spectral curves, and the relative reflectance of soil increased during 350-1 750 nm wave length along with the increase of the sand proportion; for treatment CK, C1, C2 and C3, the soil spectral reflectance （y） and wave length （x） appeared highly correlated relationships, they were y=0.18 71 In（x）-0.979 4, y=0.158 7 In（x）-0.801 2, y=0.177 1 In（x）-0.910 8 and y=0.184 5 In（x）-0.944 5, respectively. [Conclusion] Synthesizing the soil physical properties and related spectral character indices, treatment C2 generated the best combination ratio of feldspathic sandstone and sand.展开更多
文摘稳态、饱和条件下,以速度v=0.214 cm min-1和0.470 cm min-1进行混合置换实验,研究大肠杆菌在砂质壤土中的运移,并根据平衡与非平衡假设下,对流-弥散方程数学模型进行数值模拟。结果表明,含非平衡的双点吸附、且含有不可逆滞留项的模型能够较好地模拟大肠杆菌在砂质壤土中的运移。模拟和实验结果均表明,大肠杆菌的BTC(Breakthrough Curve穿透曲线)与示踪剂相比峰值明显降低,拖尾明显,且出现延迟,总的流出量也明显少于示踪剂;当水流速度由0.214 cm min-1增至0.470 cm min-1时,大肠杆菌BTC峰值由0.05增至0.2,且随速度的增加,滞留系数减小。
基金Supported by Jiangsu Agricultural Science and Technology Innovation Fund[CX(13)3031]~~
文摘[Objective]The aim was to research water retention of superabsorbent polymer （SAP） in sandy soils. [Method] With soils from an ancient course in the Yel ow River as materials, acrylate SAP was taken as water retention materials to conduct the test. [Result] With 0.2%-0.4% SAP added, dewatering period of sandy soil extended after irrigation; the period of water retention quantity over 10% last for 42 d, which was significantly more than that of the control group in 16 d （saturated water reducing to 10%）; water retention effect proved better at the 2nd irrigation without soil stirring compared with the 1st irrigation. [Conclusion] The mixture of SAP with sandy soils promotes water retention in soils.
基金Supported by the Special Fund for the Scientific Research in Public Interest of the Ministry of Land and Resources(201411008)~~
文摘[Objective] To study the soil texture, water storage and related spectral characteristics of composited soil. [Method] 3 different ratios of composited soils was designed by using feldspathic sandstone and sand by 3 different ratios, 1：1（C1）, 1：2（C2） and 1：5（C3）, and the CK used loess soil and sand by 1：2, then the soil texture, water storage, soil and winter wheat spectral characteristic were measured and analyzed under those treatments in 2010-2013. [Result] （1） With the increasing of the plant- ing year, treatment C1, C2 and C3 all showed decreasing in the proportions of sand and increasing of silt and the CK showed decreasing of clay and increasing of sand, along 1-30 cm soil depth. Treatment C2 showed the proportion of sand, silt and clay were 76.69%, 18.72% and 4.70%, respectively. （2） The water contents of all the treatments were significant different from other in 0-60 cm soil depth, and showed increasing trend with the increasing of sand proportion. Treatment C2 had higher average water content during the 3 years than treatment CK, C1 and C3 by 21.34%, 11.59% and 3.91% in the same soil depth, respectively. （3） In 2013, the spectral reflection curve characters were similar for all treatment of winter wheat at the jointing stage and filling stage along the full-wave band （350-2 500 nm）, and the reflectance was higher in the jointing stage than the filling stage; the reflection peak was found around 550 nm, a part of green light wave band. Treatment C2 showed the highest canopy that all treatments had similar spectral curves, and the relative reflectance of soil increased during 350-1 750 nm wave length along with the increase of the sand proportion; for treatment CK, C1, C2 and C3, the soil spectral reflectance （y） and wave length （x） appeared highly correlated relationships, they were y=0.18 71 In（x）-0.979 4, y=0.158 7 In（x）-0.801 2, y=0.177 1 In（x）-0.910 8 and y=0.184 5 In（x）-0.944 5, respectively. [Conclusion] Synthesizing the soil physical properties and related spectral character indices, treatment C2 generated the best combination ratio of feldspathic sandstone and sand.
