In order to study the movement characteristics of groundwater in a deep mining area and solve the dispute of the distri- bution rule of hydro-chemical zoning which is contradicted by lixiviation water zoning in a hori...In order to study the movement characteristics of groundwater in a deep mining area and solve the dispute of the distri- bution rule of hydro-chemical zoning which is contradicted by lixiviation water zoning in a horizontal direction, we directed our attention to the source of deep groundwater, its seepage and hydro-chemical characteristics in a typical mining area. We used a neotectonic water-control theory, chemical and isotope methods, as well as a method for analyzing dynamic groundwater conditions. The results indicate that 1) Karst water in the deep and medium parts of this mining area is recharged by vertical leakage through neotectonic fractures rather than seepage along strata from subcrop parts or surrounding flows; 2) from surface to deep leakage paths, the variation in the types of chemical groundwater agrees with the normal lixiviation water distribution rule and the age of mixed groundwater increases; 3) the water-rich zones along neotectonic fractures correspond with water-diluted zones in a hori-zontal direction; 4) the leakage coefficient and water capacity of aquifers increases during the flow process of Karst water along the antidip direction (from west to east) and 5) Karst water in shallow mining areas forms a strong runoff belt along strikes and quickly dilutes the water from deep and medium mining areas. Overall, chemical and dynamic water characteristics actually agree with in terms of the entire consideration for differences in vertical leakage and abnormalities in the zone of water chemical distribution, along a horizontal runoff direction.展开更多
Methane oxidation by paddy soils in a closed system could be simulsted by the equation where xo and x are the CH4 concentrations at time zero and t, respectively; k1 and k2 are constants related to the constant of fir...Methane oxidation by paddy soils in a closed system could be simulsted by the equation where xo and x are the CH4 concentrations at time zero and t, respectively; k1 and k2 are constants related to the constant of first-order-kinetics. According to the equation the change of soil ability to oxidize CH4 could be estimated by the equstion The results showed that the soil ability to oxidize CH4 varied, depending on the initial CH4 concentration.High initial CH4 concentration stimulated soil ability to consume CH4, while low concentration depressed the ability. This characteristic of paddy soil seemed to be of considerable significance to self-adjusting CH4 emission from flooded rice fields if there exist oxic microsites in the soil.展开更多
An ion chromatographic method with a valve switching facility was developed to determine trace nitrate concentrations in seawater using two pumps, two different suppressors, and two columns. A carbohydrate membrane de...An ion chromatographic method with a valve switching facility was developed to determine trace nitrate concentrations in seawater using two pumps, two different suppressors, and two columns. A carbohydrate membrane desalter was used to reduce the high concentrations of sodium salts in samples. In this method, trace nitrate was eluted from the concentrator column to the analytical columns, while the matrix fl owed to waste. Neither chemical pre-treatment nor sample dilution was required. In the optimized separation conditions, the method showed good linearity( R >0.99) in the 0.05 and 50 mg/L concentration range, and satisfactory repeatability(RSD<5%, n =6). The limit of detection for nitrate was 0.02 mg/L. Results showed that the valve switching system was suitable and practical for the determination of trace nitrate in seawater.展开更多
Field experiment was carried out to nitrogen release characteristics of rice controlled release fertilizer (RCRF) coated with natural and half natural high molecular materials, and to thereof effects on the nitrogen u...Field experiment was carried out to nitrogen release characteristics of rice controlled release fertilizer (RCRF) coated with natural and half natural high molecular materials, and to thereof effects on the nitrogen uptake and yield of early and late hybrid rice from 1999 to 2000, with urea as control.In experimental fields regardless of early and late seasons, the amount of N in the plants increased exponentially at the early growth stage (y=abx) and nonlinearly at the middle and late growth stages (y=a+bx+cx2).Rice controlled release fertilizer lengthened the exponential phase and increased the parameter -b/c during the nonlinear phase. Although the N amount of plants was less in rice controlled release fertilizer plots man in urea plots within 20 days after transplanting, at the heading and maturity stages, the N amount of plants in rice controlled release fertilizer plots was above two times greater than in the urea plots due to the higher N recovery, and the high absorption density of N in the nonlinear phase.Tillers pattern and achievement of the maximum tillering stage varied with fertilizer types. The maximum tillering stage in the urea plots occurred a week earlier than in the rice controlled release fertilizer plots. Yield sink size and potential sink size of the plants reflected the N absorption pattern and the amount of N in the plants. The yields of early and late rice with 90 kg N ha-1 of rice controlled release fertilizer were respectively increased by 832.7 kg ha-1 and 412.8 kg ha-1 than those with 90 kg N ha-1 of urea, almost equivalent to the yield of early and late hybrid rice with 180 kg N ha-1 of urea.展开更多
Sediment-water interfaces are important interfaces for lakes,which are related to most environmental and ecological problems.Wind-induced waves cause secondary pollution via sediment resuspension.Since the coupling me...Sediment-water interfaces are important interfaces for lakes,which are related to most environmental and ecological problems.Wind-induced waves cause secondary pollution via sediment resuspension.Since the coupling mechanism of water,resuspended sediments,and phosphorus affects the release of phosphorus(P)near the interface,a coupled model was explored for two sediment types with different adsorption-desorption capabilities to examine sediment resuspension and P release.The relationships among wind speed,wave characteristics,sediment distribution and P concentration were obtained.For different sediments,the unit sediment desorption release is negatively correlated with wind speed.When sediments are resuspended under low or moderate wind speed,the P concentration in the overlying water increases abruptly,hampering diffusion.P release exhibits the characteristics of concentrated release in a small region and changes the water environment rapidly.展开更多
基金Projects 2007CB209400 supported by the National Basic Research Program of China, 5057409050634050 by the National Natural Science Foundation of China
文摘In order to study the movement characteristics of groundwater in a deep mining area and solve the dispute of the distri- bution rule of hydro-chemical zoning which is contradicted by lixiviation water zoning in a horizontal direction, we directed our attention to the source of deep groundwater, its seepage and hydro-chemical characteristics in a typical mining area. We used a neotectonic water-control theory, chemical and isotope methods, as well as a method for analyzing dynamic groundwater conditions. The results indicate that 1) Karst water in the deep and medium parts of this mining area is recharged by vertical leakage through neotectonic fractures rather than seepage along strata from subcrop parts or surrounding flows; 2) from surface to deep leakage paths, the variation in the types of chemical groundwater agrees with the normal lixiviation water distribution rule and the age of mixed groundwater increases; 3) the water-rich zones along neotectonic fractures correspond with water-diluted zones in a hori-zontal direction; 4) the leakage coefficient and water capacity of aquifers increases during the flow process of Karst water along the antidip direction (from west to east) and 5) Karst water in shallow mining areas forms a strong runoff belt along strikes and quickly dilutes the water from deep and medium mining areas. Overall, chemical and dynamic water characteristics actually agree with in terms of the entire consideration for differences in vertical leakage and abnormalities in the zone of water chemical distribution, along a horizontal runoff direction.
文摘Methane oxidation by paddy soils in a closed system could be simulsted by the equation where xo and x are the CH4 concentrations at time zero and t, respectively; k1 and k2 are constants related to the constant of first-order-kinetics. According to the equation the change of soil ability to oxidize CH4 could be estimated by the equstion The results showed that the soil ability to oxidize CH4 varied, depending on the initial CH4 concentration.High initial CH4 concentration stimulated soil ability to consume CH4, while low concentration depressed the ability. This characteristic of paddy soil seemed to be of considerable significance to self-adjusting CH4 emission from flooded rice fields if there exist oxic microsites in the soil.
基金Supported by the National Special Fund for Major Research Instrumentation Development(No.2012YQ090229)the Instrument Functional Exploitation and Technical Innovation Fund,Chinese Academy of Sciences(No.yg2010072)the Shandong Provincial Technology Development Plan Fund(Nos.2011SJGZ06,2012SJGZ12,2012424012)
文摘An ion chromatographic method with a valve switching facility was developed to determine trace nitrate concentrations in seawater using two pumps, two different suppressors, and two columns. A carbohydrate membrane desalter was used to reduce the high concentrations of sodium salts in samples. In this method, trace nitrate was eluted from the concentrator column to the analytical columns, while the matrix fl owed to waste. Neither chemical pre-treatment nor sample dilution was required. In the optimized separation conditions, the method showed good linearity( R >0.99) in the 0.05 and 50 mg/L concentration range, and satisfactory repeatability(RSD<5%, n =6). The limit of detection for nitrate was 0.02 mg/L. Results showed that the valve switching system was suitable and practical for the determination of trace nitrate in seawater.
文摘Field experiment was carried out to nitrogen release characteristics of rice controlled release fertilizer (RCRF) coated with natural and half natural high molecular materials, and to thereof effects on the nitrogen uptake and yield of early and late hybrid rice from 1999 to 2000, with urea as control.In experimental fields regardless of early and late seasons, the amount of N in the plants increased exponentially at the early growth stage (y=abx) and nonlinearly at the middle and late growth stages (y=a+bx+cx2).Rice controlled release fertilizer lengthened the exponential phase and increased the parameter -b/c during the nonlinear phase. Although the N amount of plants was less in rice controlled release fertilizer plots man in urea plots within 20 days after transplanting, at the heading and maturity stages, the N amount of plants in rice controlled release fertilizer plots was above two times greater than in the urea plots due to the higher N recovery, and the high absorption density of N in the nonlinear phase.Tillers pattern and achievement of the maximum tillering stage varied with fertilizer types. The maximum tillering stage in the urea plots occurred a week earlier than in the rice controlled release fertilizer plots. Yield sink size and potential sink size of the plants reflected the N absorption pattern and the amount of N in the plants. The yields of early and late rice with 90 kg N ha-1 of rice controlled release fertilizer were respectively increased by 832.7 kg ha-1 and 412.8 kg ha-1 than those with 90 kg N ha-1 of urea, almost equivalent to the yield of early and late hybrid rice with 180 kg N ha-1 of urea.
基金supported by the Strategic Priority Research Program of the National Key R&D Program of China(Grant Nos.201BYf,CJ505500,and 201BYFCI505504)the National Natural Science Foundation of China(NSFC)(Grant Nos.11802313,and 12032005).
文摘Sediment-water interfaces are important interfaces for lakes,which are related to most environmental and ecological problems.Wind-induced waves cause secondary pollution via sediment resuspension.Since the coupling mechanism of water,resuspended sediments,and phosphorus affects the release of phosphorus(P)near the interface,a coupled model was explored for two sediment types with different adsorption-desorption capabilities to examine sediment resuspension and P release.The relationships among wind speed,wave characteristics,sediment distribution and P concentration were obtained.For different sediments,the unit sediment desorption release is negatively correlated with wind speed.When sediments are resuspended under low or moderate wind speed,the P concentration in the overlying water increases abruptly,hampering diffusion.P release exhibits the characteristics of concentrated release in a small region and changes the water environment rapidly.
