农业用水是我国西北内陆绿洲的主要水耗途径.研究农业节水灌溉对于缓解农业和生态用水矛盾以及当地农民生计都有重要的意义.基于民勤县传统农耕习惯(漫灌和灌水定频),以干旱区5种典型农作物(玉米、棉花、辣椒、向日葵、小麦)为研究对象...农业用水是我国西北内陆绿洲的主要水耗途径.研究农业节水灌溉对于缓解农业和生态用水矛盾以及当地农民生计都有重要的意义.基于民勤县传统农耕习惯(漫灌和灌水定频),以干旱区5种典型农作物(玉米、棉花、辣椒、向日葵、小麦)为研究对象,在保持当地灌溉频率下,揭示5个灌水定额(1800,1440,1080,720,360 m3/hm2)对5种作物的产量、生物量、灌溉水利用效率(irrigation water use efficiency,IWUE)以及单位水收益(economic water productivity,EWP)的影响,明确不同作物获得高水分生产效率和单位水收益的最适灌溉制度,以指导当地灌溉实践.结果显示:(1)玉米5个灌水定额下IWUE均高于其余4种作物,最高为12.27 kg/m3;(2)棉花平均EWP均高于其余4种作物,两年平均8.0元/m3,棉花水资源投入经济产出最优;(3)综合考虑产量、IWUE、EWP以及生物量,玉米优于其余4种作物;(4)1080 m3/hm2可以作为向日葵实际生产灌水定额,720 m3/hm2为适合玉米、辣椒、小麦、棉花的灌水定额.本研究表明在石羊河流域减少灌水定额能够有效提高当地水分利用效率以及单位水收益.(图5表1参38附表2)展开更多
Peel essential oil of bergamot （Citrus bergamia Risso） growing in Tunisia was separated by hydrodistillation and obtained in a yield of 9.7%. The oil composition was investigated using GC and GC-MS with two columns ...Peel essential oil of bergamot （Citrus bergamia Risso） growing in Tunisia was separated by hydrodistillation and obtained in a yield of 9.7%. The oil composition was investigated using GC and GC-MS with two columns HP-I and HP-Innowax. Fifteen compounds accounting for 98.52% of the oil were identified. The oil was characterized by bigb content oflimonene （59.21%）, linalool （9.51%） and linalyl acetate （16.83%）.展开更多
This study evaluated the reduction of water consumption in a SIH （social interest housing） complex from the simulation of implanting a rainwater harvesting system. The methodology consisted of characterization of th...This study evaluated the reduction of water consumption in a SIH （social interest housing） complex from the simulation of implanting a rainwater harvesting system. The methodology consisted of characterization of the case study, survey data of water consumption and data of precipitation in the area, on-site visits to define the average consumption and monthly water distribution, and sizing of a rainwater harvesting tank following the Netuno Program. It was obtained 22.500 L as the ideal volume for the tank, supplying the demand for drinkingwater in 32%, although the reduction in the drinking water bills would be minor, since the object of the case study is considered SIH, and residents pay a fixed fee for consuming up to 10 m3 per month. Therefore, it becomes necessary to analyze this situation from a sustainable and environmental perspective, and the benefits are no longer only economic, but rather they take on a more comprehensive social dimension.展开更多
A comprehensive evaluation is made in this article On the ec-benefit, social benefit, and economic benefit form banana planting of a company in three planting bases in Xinping County. Before the banana is planted, the...A comprehensive evaluation is made in this article On the ec-benefit, social benefit, and economic benefit form banana planting of a company in three planting bases in Xinping County. Before the banana is planted, the land is classified into Sloppy land, woodland and amble land We earefidly study the three types of land, analyze the various effects and benefits made by banana planting on these types of land, and make a eomprehensive, comment.展开更多
The skewness of the return distribution is one of the important features of the security price.In this paper,the authors try to explore the relationship between the skewness and the coefficient ofrisk premium.The coef...The skewness of the return distribution is one of the important features of the security price.In this paper,the authors try to explore the relationship between the skewness and the coefficient ofrisk premium.The coefficient of the risk premium is estimated by a GARCH-M model,and the robustmeasurement of skewness is calculated by Groeneveld-Meeden method.The empirical evidences forthe composite indexes from 33 securities markets in the world indicate that the risk compensationrequirement in the market where the return distribution is positively skewed is virtually zero,andthe risk compensation requirement is positive in a significant level in the market where the returndistribution is negative skewed.Moreover,the skewness is negatively correlated with the coefficient ofthe risk premium.展开更多
文摘农业用水是我国西北内陆绿洲的主要水耗途径.研究农业节水灌溉对于缓解农业和生态用水矛盾以及当地农民生计都有重要的意义.基于民勤县传统农耕习惯(漫灌和灌水定频),以干旱区5种典型农作物(玉米、棉花、辣椒、向日葵、小麦)为研究对象,在保持当地灌溉频率下,揭示5个灌水定额(1800,1440,1080,720,360 m3/hm2)对5种作物的产量、生物量、灌溉水利用效率(irrigation water use efficiency,IWUE)以及单位水收益(economic water productivity,EWP)的影响,明确不同作物获得高水分生产效率和单位水收益的最适灌溉制度,以指导当地灌溉实践.结果显示:(1)玉米5个灌水定额下IWUE均高于其余4种作物,最高为12.27 kg/m3;(2)棉花平均EWP均高于其余4种作物,两年平均8.0元/m3,棉花水资源投入经济产出最优;(3)综合考虑产量、IWUE、EWP以及生物量,玉米优于其余4种作物;(4)1080 m3/hm2可以作为向日葵实际生产灌水定额,720 m3/hm2为适合玉米、辣椒、小麦、棉花的灌水定额.本研究表明在石羊河流域减少灌水定额能够有效提高当地水分利用效率以及单位水收益.(图5表1参38附表2)
文摘Peel essential oil of bergamot （Citrus bergamia Risso） growing in Tunisia was separated by hydrodistillation and obtained in a yield of 9.7%. The oil composition was investigated using GC and GC-MS with two columns HP-I and HP-Innowax. Fifteen compounds accounting for 98.52% of the oil were identified. The oil was characterized by bigb content oflimonene （59.21%）, linalool （9.51%） and linalyl acetate （16.83%）.
文摘This study evaluated the reduction of water consumption in a SIH （social interest housing） complex from the simulation of implanting a rainwater harvesting system. The methodology consisted of characterization of the case study, survey data of water consumption and data of precipitation in the area, on-site visits to define the average consumption and monthly water distribution, and sizing of a rainwater harvesting tank following the Netuno Program. It was obtained 22.500 L as the ideal volume for the tank, supplying the demand for drinkingwater in 32%, although the reduction in the drinking water bills would be minor, since the object of the case study is considered SIH, and residents pay a fixed fee for consuming up to 10 m3 per month. Therefore, it becomes necessary to analyze this situation from a sustainable and environmental perspective, and the benefits are no longer only economic, but rather they take on a more comprehensive social dimension.
文摘A comprehensive evaluation is made in this article On the ec-benefit, social benefit, and economic benefit form banana planting of a company in three planting bases in Xinping County. Before the banana is planted, the land is classified into Sloppy land, woodland and amble land We earefidly study the three types of land, analyze the various effects and benefits made by banana planting on these types of land, and make a eomprehensive, comment.
基金supported by China Natural Science Foundation (70701035, 70425004 and 70221001)Hunan Natural Science Foundation (09JJ1010)+1 种基金the Key Research Institute of PhilosophiesSocial Sciences in Hunan Universities
文摘The skewness of the return distribution is one of the important features of the security price.In this paper,the authors try to explore the relationship between the skewness and the coefficient ofrisk premium.The coefficient of the risk premium is estimated by a GARCH-M model,and the robustmeasurement of skewness is calculated by Groeneveld-Meeden method.The empirical evidences forthe composite indexes from 33 securities markets in the world indicate that the risk compensationrequirement in the market where the return distribution is positively skewed is virtually zero,andthe risk compensation requirement is positive in a significant level in the market where the returndistribution is negative skewed.Moreover,the skewness is negatively correlated with the coefficient ofthe risk premium.
