The reduction of soil and water losses under furrow irrigation with saline water is important to environmental protection and agricultural production. The objective of this study was to determine the effect of polyacr...The reduction of soil and water losses under furrow irrigation with saline water is important to environmental protection and agricultural production. The objective of this study was to determine the effect of polyacrylamide (PAM) application on soil infiltration and erosion under simulated furrow irrigation with saline water. Polyacrylamide was applied by dissolving it in irrigation water at the rates of 1.5, 7.5, and 15.0 mg L-1 or spreading it as a powder on soil surface at the rates of 0.3, 1.5, 3.0, and 6.0 g m-2, respectively. The electrolyte concentration of tested irrigation water was 10 and 30 mmolc L-1 and its sodium adsorption ratio (SAR) was 0.5, 10.0, and 20.0 (mmolc L-1)0.5. Distilled water was used as a control for irrigation water quality. Results indicated that the electrolyte concentration and SAR generally did not significantly affect soil and water losses after PAM application. Infiltration rate and total infiltration volume decreased with the increase of PAM application rate. Polyacrylamide application in both methods significantly reduced soil erosion, but PAM application rate did not significantly affect it. The solution PAM application was more effective in controlling soil erosion than the powdered PAM application, but the former exerted a greater adverse influence on soil infiltration than the latter. Under the same total amounts, the powdered PAM application resulted in a 38.2%-139.6% greater infiltration volume but a soil mass loss of 1.3-3.4 times greater than the solution PAM application.展开更多
The dielectric performance of alkali activated slag （AAS） cement paste was investigated in the frequency range of 1 to 1000 MHz. The experimental results showed the unstable dielectric properties of harden paste wer...The dielectric performance of alkali activated slag （AAS） cement paste was investigated in the frequency range of 1 to 1000 MHz. The experimental results showed the unstable dielectric properties of harden paste were mostly influenced by the fraction of free water in paste or absorbed water from ambient, but not including hydration water and microstructure. The free water was completely eliminated by heat treatment at 105 ℃ about 4 hours, and then its dielectric loss was depressed; but with the exposure time in air increasing, the free water adsorption in ambient air made the dielectric property of harden cement paste to be bad. The temperature and relative humidity of environment was the key factors of free water adsorption; hence, if the influence of free water on dielectric constant was measured or eliminated, the cement-based materials may be applied in humidity sensitive materials or dielectric materials domains.展开更多
A spray-drying assisted solid-state method to prepare spherical layer-structured H_(2)TiO_(3) ion sieve(LSTIS)particles is reported herein.The effects of synthesis parameters(calcination temperature,calcination time,a...A spray-drying assisted solid-state method to prepare spherical layer-structured H_(2)TiO_(3) ion sieve(LSTIS)particles is reported herein.The effects of synthesis parameters(calcination temperature,calcination time,and the lithium-titanium molar ratio)on adsorption-desorption performance(the delithiation ratio,titanium dissolution loss,and the adsorption capacity)were investigated.The as-prepared LSTIS exhibited an equilibrium adsorption capacity of 30.08 mg·g^(-1)(average of 25.85 mg·g^(-1) over 5 cycles)and ultra-low titanium dissolution loss of less than 0.12%(average of 0.086%over 5 cycles).The LSTIS showed excellent selectivity toward Li^(+) in Na^(+),K^(+),Mg^(2+),and Ca^(2+) coexisting saline solutions where its adsorption capacity reached 27.45 mg·g^(-1) and the separation factors of Li^(+) over the coexisting cations exceeded 100.The data suggests that the LSTIS is promising to competitively enrich Li^(+) from saline solutions.展开更多
Irrigation-induced soil erosion seriously affects the sustainability of irrigated agriculture. The effects of irrigation water quality and furrow gradient on runoff and soil loss were studied under simulated furrow ir...Irrigation-induced soil erosion seriously affects the sustainability of irrigated agriculture. The effects of irrigation water quality and furrow gradient on runoff and soil loss were studied under simulated furrow irrigation in laboratory using a soil collected from an experimental station of China Agricultural University, North China. The experimental treatments were different combinations of irrigation water salt concentrations of 5, 10, 20, and 30 mmol c L-1 , sodium adsorption ratios (SAR) of 0.5, 5.0, and 10.0 (mmol c L-1 ) 0.5 , and furrow gradients of 1%, 3%, and 5%, with distilled water for irrigation at 3 furrow gradients as controls. The experimental data indicated that total runoff amount, sediment concentration in runoff, and total soil loss amount generally decreased with increasing salt concentration in irrigation water but increased with its sodicity and furrow gradient. The effects of water quality and furrow gradient on soil loss were greater than those on runoff, and the increase of furrow gradient decreased the influence of water quality on soil loss. When the salt concentration increased from 5 to 30 mmol c L-1 at SAR of 10.0 (mmol c L-1 ) 0.5 , total runoff amount, sediment concentration, and total soil loss amount decreased by 3.89%, 52.1%, and 53.92%, and 10.57%, 38.86%, and 42.03% at the furrow gradients of 1% and 5%, respectively. However, they respectively increased by 3.37%, 45.34%, and 55.36%, and 3.86%, 10.77%, and 13.91% when SAR increased from 0.5 to 10.0 (mmol c L-1 ) 0.5 at the salt concentration of 5 mmol c L-1 . Irrigation water quality and furrow gradient should be comprehensively considered in the planning and management of furrow irrigation practices to decrease soil loss and improve water utilization efficiency.展开更多
基金the National Natural Science Foundation of China (No.40635027)the State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau of China (No.10501-169)
文摘The reduction of soil and water losses under furrow irrigation with saline water is important to environmental protection and agricultural production. The objective of this study was to determine the effect of polyacrylamide (PAM) application on soil infiltration and erosion under simulated furrow irrigation with saline water. Polyacrylamide was applied by dissolving it in irrigation water at the rates of 1.5, 7.5, and 15.0 mg L-1 or spreading it as a powder on soil surface at the rates of 0.3, 1.5, 3.0, and 6.0 g m-2, respectively. The electrolyte concentration of tested irrigation water was 10 and 30 mmolc L-1 and its sodium adsorption ratio (SAR) was 0.5, 10.0, and 20.0 (mmolc L-1)0.5. Distilled water was used as a control for irrigation water quality. Results indicated that the electrolyte concentration and SAR generally did not significantly affect soil and water losses after PAM application. Infiltration rate and total infiltration volume decreased with the increase of PAM application rate. Polyacrylamide application in both methods significantly reduced soil erosion, but PAM application rate did not significantly affect it. The solution PAM application was more effective in controlling soil erosion than the powdered PAM application, but the former exerted a greater adverse influence on soil infiltration than the latter. Under the same total amounts, the powdered PAM application resulted in a 38.2%-139.6% greater infiltration volume but a soil mass loss of 1.3-3.4 times greater than the solution PAM application.
文摘The dielectric performance of alkali activated slag （AAS） cement paste was investigated in the frequency range of 1 to 1000 MHz. The experimental results showed the unstable dielectric properties of harden paste were mostly influenced by the fraction of free water in paste or absorbed water from ambient, but not including hydration water and microstructure. The free water was completely eliminated by heat treatment at 105 ℃ about 4 hours, and then its dielectric loss was depressed; but with the exposure time in air increasing, the free water adsorption in ambient air made the dielectric property of harden cement paste to be bad. The temperature and relative humidity of environment was the key factors of free water adsorption; hence, if the influence of free water on dielectric constant was measured or eliminated, the cement-based materials may be applied in humidity sensitive materials or dielectric materials domains.
基金financially supported by the Prospective Joint Research Project of Industry,University and Research in Jiangsu Province(BY2016005-11)National Science and Technology Support Plan(No.2013BAE111B03)。
文摘A spray-drying assisted solid-state method to prepare spherical layer-structured H_(2)TiO_(3) ion sieve(LSTIS)particles is reported herein.The effects of synthesis parameters(calcination temperature,calcination time,and the lithium-titanium molar ratio)on adsorption-desorption performance(the delithiation ratio,titanium dissolution loss,and the adsorption capacity)were investigated.The as-prepared LSTIS exhibited an equilibrium adsorption capacity of 30.08 mg·g^(-1)(average of 25.85 mg·g^(-1) over 5 cycles)and ultra-low titanium dissolution loss of less than 0.12%(average of 0.086%over 5 cycles).The LSTIS showed excellent selectivity toward Li^(+) in Na^(+),K^(+),Mg^(2+),and Ca^(2+) coexisting saline solutions where its adsorption capacity reached 27.45 mg·g^(-1) and the separation factors of Li^(+) over the coexisting cations exceeded 100.The data suggests that the LSTIS is promising to competitively enrich Li^(+) from saline solutions.
基金Project supported by the State Key Laboratory of Soil Erosion and Dryland Farming on Loess Plateau of China(No. 10501-169)the National Natural Science Foundation of China (No. 40635027)+1 种基金the National Hi-Tech Research and Development Program of China (No. 2006AA100205)the Program for Changjiang Scholars and Innovative ResearchTeam in University of China (No. IRT0657)
文摘Irrigation-induced soil erosion seriously affects the sustainability of irrigated agriculture. The effects of irrigation water quality and furrow gradient on runoff and soil loss were studied under simulated furrow irrigation in laboratory using a soil collected from an experimental station of China Agricultural University, North China. The experimental treatments were different combinations of irrigation water salt concentrations of 5, 10, 20, and 30 mmol c L-1 , sodium adsorption ratios (SAR) of 0.5, 5.0, and 10.0 (mmol c L-1 ) 0.5 , and furrow gradients of 1%, 3%, and 5%, with distilled water for irrigation at 3 furrow gradients as controls. The experimental data indicated that total runoff amount, sediment concentration in runoff, and total soil loss amount generally decreased with increasing salt concentration in irrigation water but increased with its sodicity and furrow gradient. The effects of water quality and furrow gradient on soil loss were greater than those on runoff, and the increase of furrow gradient decreased the influence of water quality on soil loss. When the salt concentration increased from 5 to 30 mmol c L-1 at SAR of 10.0 (mmol c L-1 ) 0.5 , total runoff amount, sediment concentration, and total soil loss amount decreased by 3.89%, 52.1%, and 53.92%, and 10.57%, 38.86%, and 42.03% at the furrow gradients of 1% and 5%, respectively. However, they respectively increased by 3.37%, 45.34%, and 55.36%, and 3.86%, 10.77%, and 13.91% when SAR increased from 0.5 to 10.0 (mmol c L-1 ) 0.5 at the salt concentration of 5 mmol c L-1 . Irrigation water quality and furrow gradient should be comprehensively considered in the planning and management of furrow irrigation practices to decrease soil loss and improve water utilization efficiency.
