营营役役之余,不晓得多少人还有寻根究底的闲情?梳理典籍眉目,从前要翻江倒海,如今,上这个那个方便网寻查一下,依赖几根指头,就能得到一个大概。然而硬生生地输入"草根"二字,跑出的几百则都是那些有原则有态度的社会学论述,...营营役役之余,不晓得多少人还有寻根究底的闲情?梳理典籍眉目,从前要翻江倒海,如今,上这个那个方便网寻查一下,依赖几根指头,就能得到一个大概。然而硬生生地输入"草根"二字,跑出的几百则都是那些有原则有态度的社会学论述,谈的乃是草根阶层——草根作为一个阶层的符码代号,摆明车马就有down to earth的地道庶民姿态。展开更多
In order to investigate the correlation between the variations in the environmental water quality indexes and the distance of water bodies from the planting region of vetiver, samples of surface water were gathered fr...In order to investigate the correlation between the variations in the environmental water quality indexes and the distance of water bodies from the planting region of vetiver, samples of surface water were gathered from the water bodies surrounding an abandoned coal gangue mountain of Dahead coal mine (Dahe, Liupanshui, Guizhou Province) based on the method of field survey and typical analysis. According to the results, the planting of vetiver could effectively purify the water bodies surrounding the coal gangue mountain. Detailed findings include three aspects:(1) The main pollutants detected in water bodies around the coal gangue mountain were SO4 2-, NO3 -, Fe and Cu, with a concentration of 869.45, 35.16, 26.06, and 40.85 mg/L respectively in wet season and all exceeded the national environmental standards for surface water.(2) The pH values of water bodies 150~200 m away from the vetiver planting region stayed within the limits of national environmental standards for surface water and presented a homogeneous feature, revealing that vetiver has the capacity to adjust the pH of the surrounding water body.(3) The contents of Fe, Mn, Cu, SO4 2-, and NO3 - under all treatments, tended to increase with the increasing distance of water bodies from the vetiver planting region;it means the shorter the distance between the water body and the vetiver planting region is, the higher the adsorption rate and purification effects will be;the optimal concentrations of Fe, Mn, and Cu were 0 mg/L, much lower than the national environmental standards for surface water.展开更多
We determined the global yield and composition of extracts from vetiver roots cultivated hydroponically. We extracted roots of two varieties collected at different times after planting. The extracts were obtained by s...We determined the global yield and composition of extracts from vetiver roots cultivated hydroponically. We extracted roots of two varieties collected at different times after planting. The extracts were obtained by supercritical fluid extraction （SFE）; we also estimated manufacturing costs. Constituents were quantified by gas-chromatography/time ionization detection （GC-FID）. Results demonstrated the efficacy of a hydroponic system in producing vctiver with a high root extract content. The largest yield was obtained from roots collected on days 132 and 92 after planting from varieties National （1.41%） and Bourbon （1.28%）, respectively. The major compounds present in the extract were khusimoi, isovalencenol, alpha-vetivone and beta-vetivone. To determine the economic viability of producing these extracts, manufacturing costs were estimated using a simplified methodology. The manufacturing costs were US$ 22.26/kg and US$ 24.26/kg for varieties national and Bourbon, respectively.展开更多
In Burkina Faso, significant amounts of endosulfan are applied to cotton fields; in addition, urban vegetable agriculture is often characterised by high fertiliser inputs, such as urban solid wastes containing heavy m...In Burkina Faso, significant amounts of endosulfan are applied to cotton fields; in addition, urban vegetable agriculture is often characterised by high fertiliser inputs, such as urban solid wastes containing heavy metals(e.g., Cu and Cd). Thus, the relevance of surrounding cotton and urban vegetable plots with vetiver(Vetiveria zizanioides) hedges to reduce environmental pollution by micropollutants was investigated using a leaching experiment, with outdoor lysimeters filled with two representative agricultural soils of Burkina Faso: Vertisol and Lixisol. After 6 months, little Cu was found in the leachates(< 0.010% of the applied amount) due to its high adsorption coefficient and its tendency to remain at the soil surface. Despite leachate and bromide recoveries being greater in soils planted with vetiver grass than in the bare soils, smaller amounts of endosulfan and Cd were found in the effluents from the planted soils(0.01% to 0.70% of the applied amount) than in those from the bare soils(0.01% to 1.48% of the applied amount), in agreement with their adsorption coefficients. These results may also be explained by a greater degradation of endosulfan in planted soils compared to bare soils and the absorption of Cd by vetiver. Thus, vetiver may decrease the risk of groundwater contamination,especially for Cd and endosulfan, which are more mobile than Cu. In addition, despite the smaller amounts of endosulfan and Cd measured in the Vertisol leachates(0.01% and 0.04% of the applied amount, respectively) compared to the Lixisol leachates, vetiver was more effective in decreasing the leaching of micropollutants if planted on Lixisol rather than on Vertisol. Further field monitoring is necessary to demonstrate the effectiveness of vetiver under the climatic conditions of Burkina Faso.展开更多
文摘营营役役之余,不晓得多少人还有寻根究底的闲情?梳理典籍眉目,从前要翻江倒海,如今,上这个那个方便网寻查一下,依赖几根指头,就能得到一个大概。然而硬生生地输入"草根"二字,跑出的几百则都是那些有原则有态度的社会学论述,谈的乃是草根阶层——草根作为一个阶层的符码代号,摆明车马就有down to earth的地道庶民姿态。
文摘In order to investigate the correlation between the variations in the environmental water quality indexes and the distance of water bodies from the planting region of vetiver, samples of surface water were gathered from the water bodies surrounding an abandoned coal gangue mountain of Dahead coal mine (Dahe, Liupanshui, Guizhou Province) based on the method of field survey and typical analysis. According to the results, the planting of vetiver could effectively purify the water bodies surrounding the coal gangue mountain. Detailed findings include three aspects:(1) The main pollutants detected in water bodies around the coal gangue mountain were SO4 2-, NO3 -, Fe and Cu, with a concentration of 869.45, 35.16, 26.06, and 40.85 mg/L respectively in wet season and all exceeded the national environmental standards for surface water.(2) The pH values of water bodies 150~200 m away from the vetiver planting region stayed within the limits of national environmental standards for surface water and presented a homogeneous feature, revealing that vetiver has the capacity to adjust the pH of the surrounding water body.(3) The contents of Fe, Mn, Cu, SO4 2-, and NO3 - under all treatments, tended to increase with the increasing distance of water bodies from the vetiver planting region;it means the shorter the distance between the water body and the vetiver planting region is, the higher the adsorption rate and purification effects will be;the optimal concentrations of Fe, Mn, and Cu were 0 mg/L, much lower than the national environmental standards for surface water.
文摘We determined the global yield and composition of extracts from vetiver roots cultivated hydroponically. We extracted roots of two varieties collected at different times after planting. The extracts were obtained by supercritical fluid extraction （SFE）; we also estimated manufacturing costs. Constituents were quantified by gas-chromatography/time ionization detection （GC-FID）. Results demonstrated the efficacy of a hydroponic system in producing vctiver with a high root extract content. The largest yield was obtained from roots collected on days 132 and 92 after planting from varieties National （1.41%） and Bourbon （1.28%）, respectively. The major compounds present in the extract were khusimoi, isovalencenol, alpha-vetivone and beta-vetivone. To determine the economic viability of producing these extracts, manufacturing costs were estimated using a simplified methodology. The manufacturing costs were US$ 22.26/kg and US$ 24.26/kg for varieties national and Bourbon, respectively.
基金financially supported in part by a CORUS Ⅱ Projecta Gabonese Government Fellowship
文摘In Burkina Faso, significant amounts of endosulfan are applied to cotton fields; in addition, urban vegetable agriculture is often characterised by high fertiliser inputs, such as urban solid wastes containing heavy metals(e.g., Cu and Cd). Thus, the relevance of surrounding cotton and urban vegetable plots with vetiver(Vetiveria zizanioides) hedges to reduce environmental pollution by micropollutants was investigated using a leaching experiment, with outdoor lysimeters filled with two representative agricultural soils of Burkina Faso: Vertisol and Lixisol. After 6 months, little Cu was found in the leachates(< 0.010% of the applied amount) due to its high adsorption coefficient and its tendency to remain at the soil surface. Despite leachate and bromide recoveries being greater in soils planted with vetiver grass than in the bare soils, smaller amounts of endosulfan and Cd were found in the effluents from the planted soils(0.01% to 0.70% of the applied amount) than in those from the bare soils(0.01% to 1.48% of the applied amount), in agreement with their adsorption coefficients. These results may also be explained by a greater degradation of endosulfan in planted soils compared to bare soils and the absorption of Cd by vetiver. Thus, vetiver may decrease the risk of groundwater contamination,especially for Cd and endosulfan, which are more mobile than Cu. In addition, despite the smaller amounts of endosulfan and Cd measured in the Vertisol leachates(0.01% and 0.04% of the applied amount, respectively) compared to the Lixisol leachates, vetiver was more effective in decreasing the leaching of micropollutants if planted on Lixisol rather than on Vertisol. Further field monitoring is necessary to demonstrate the effectiveness of vetiver under the climatic conditions of Burkina Faso.
