Aim The several species of the genus Paris called ＂Chonglou＂ are famous traditional Chinese herbal medicines. We established the quantitative analysis method of the steroidal saponins in some species of the genus Pa...Aim The several species of the genus Paris called ＂Chonglou＂ are famous traditional Chinese herbal medicines. We established the quantitative analysis method of the steroidal saponins in some species of the genus Paris and discussed their relations. Methods We detected the contents of 11 steroidal saponins in Paris samples with a Kromasel C18 （ 150 mm× 4.6 mm ID, 5μm） column which was subjected to gradient elution with acetonitrile-water （30：70- 60：40, V/V） at a flow rate of 1 mL· min^-1 by HPLC-ELSD and established chemical cluster tree using SPSS 11 software. Results All the samples could be separated and calibration curves of 11 saponins were prepared. We successfully detected the contents of 11 steroidal saponins in 14 Paris spp. in 30 min. The recovery for the assay of saponins was between 95 % and 97 %. The RSD of precision of 11 saponins and stability of samples were below 3 %. Chemical phylogenetic tree based on saponin contents indicated that 17 samples of Paris spp. clustered separately. Conclusion The established method is accurate and convenient, and suitable for the quantitative analysis of these 11 steroidal saponins in Paris spp.. The chemical phylogenetic tree is in accordance with Takhtajian classical taxonomy.展开更多
[Objective] The aim was to analyze temporal and spatial variation charac- teristics of potential evapotranspiration in Guizhou Province. [Method] According to information from 19 meteorological stations of Guizhou Pro...[Objective] The aim was to analyze temporal and spatial variation charac- teristics of potential evapotranspiration in Guizhou Province. [Method] According to information from 19 meteorological stations of Guizhou Province from 1960 to 2007, with the formulas of optimizational Penman-Monteith and SEBAL net radiation mod- el, the reference crop evapotranspiration ETo was calculated. Also with the spatial interpolation method of Arcgis 9.3, climate tendency rate statistics, K-M test, wavelet analysis and so on, the related regional differentiation and spatial and temporal change characteristics between meteorological factors from each monitoring station and ETo were analyzed. [Result] The results show that the correlation of potential evapotranspiration and meteorological factors in Guizhou Province demonstrates re- gional differentiation; there was no direct connection between the correlation of po- tential evapotranspiration and meteorological factors and the amount of meteorologi- cal factors in the year; there were 3 cycles in potential evapotranspiration, namely, 1 year, 5 years and 10 years, with 3 mutation points, respectively, in 1965, 1984 and 1999, mainly affected by air temperature, precipitation and solar radiation. [Conclusion] The research is of great significance in developing irrigation approach- es, adjusting agricultural structure and ecological construction.展开更多
The primary purpose of this study was to assess water losses by evapotranspiration, evaporation and seepage in arid zone.Normally, evaporation and seepage are the main causes of water losses.For modeling water losses,...The primary purpose of this study was to assess water losses by evapotranspiration, evaporation and seepage in arid zone.Normally, evaporation and seepage are the main causes of water losses.For modeling water losses,a combination of Genetic Programming(GP),Penman-Monteith(PM) and Penman combination model for measurement of evapotranspiration,evaporation and seepage has been developed.The results were found to be varying depending on how the evaporation and seepage phenomena are modeled.These results show that that there is an improvement in reducing evapotranspiration,evaporation and seepage losses in arid and semi-arid region.展开更多
The impact of the interannual variability (IAV) of vegetation on the IAV of evapotranspiration is investigated with the Community Land Model (CLM3.0) and modified Dynamic Global Vegetation Model (DGVM). Two sets of 50...The impact of the interannual variability (IAV) of vegetation on the IAV of evapotranspiration is investigated with the Community Land Model (CLM3.0) and modified Dynamic Global Vegetation Model (DGVM). Two sets of 50-year off-line simulations are used in this study. The simulations begin with the same initial surface-water and heat states and are driven by the same atmospheric forcing data. The vegetation exhibits interannual variability in one simulation but not in the other simulation. However, the climatological means for the vegetation are the same. The IAV of the 50-year annual total evapotranspiration and its three partitions (ground evaporation, canopy evaporation, and transpiration) are analyzed. The global distribution of the evapotranspiration IAV and the statistics of evapotranspiration and its components in different ecosystems show that the IAV of ground evaporation is generally large in areas dominated by grass and deciduous trees, whereas the IAV of canopy evaporation and transpiration is large in areas dominated by bare soil and shrubs. For ground evaporation, canopy evaporation, and transpiration, the changes in IAV are larger than the mean state over most grasslands and shrublands. The study of two sites with the same IAV in the leaf area index (LAI) shows that the component with the smaller contribution to the total evapotranspiration is more sensitive to the IAV of vegetation. The IAV of the three components of evapotranspiration increases with the IAV of the fractional coverage (FC) and the LAI. The ground evaporation IAV shows the greatest increase, whereas the canopy evaporation shows the smallest increase.展开更多
Evapotranspiration （ETc） is an important quantity for hydrological cycle. This study shows evapotranspiration, the ratio of evaporation to evapotranspiration （E/ETc） of winter wheat and maize in north China. Sever...Evapotranspiration （ETc） is an important quantity for hydrological cycle. This study shows evapotranspiration, the ratio of evaporation to evapotranspiration （E/ETc） of winter wheat and maize in north China. Several relationships, namely, E/ET0 and soil surface moisture, E/ET0 and leaf area index （LAI）, are also analyzed. The average seasonal ETc values for winter wheat, maize （2008） and maize （2009） are 431.21,456.3 and 341.4mm. The value of E/ET0 varied from 1 at initial growth stage to 0.295 at the later growth for winter wheat, and from 1 to 0.492, from 1 to 0.566 for maize （2008） and maize （2009）. The relationship between E/ET0 and surface soil water content, and E/ET0 and LAI are fitted to a quadratic parabola equation with significant correlation coefficients, respectively, for wheat and maize. These results should help the precise planning and efficient management of irrigation for these crops in this region.展开更多
In a case study in Tao River Basin, China, we derived a high spatial-resolution regional distribution of evapotranspiration(ET) using the single crop coefficient method and Budyko equation. We then further analyzed th...In a case study in Tao River Basin, China, we derived a high spatial-resolution regional distribution of evapotranspiration(ET) using the single crop coefficient method and Budyko equation. We then further analyzed the spatio-temporal characteristics of this diverse eco-hydrological basin from 2001–2010. The results suggest that the single crop coefficient method based on leaf area index captures better spatial and temporal dynamics of the regional ET than did the Budyko Equation method. The rising temperature was the main reason for the increasing ET in the Tao River Basin during 2001–2010. Areas with high ET efficiency were distributed mainly in the areas where the vegetation coverage was high, and a lower runoff coefficient responded. The estimated spatial patterns of ET allowed an improved understanding of the eco-hydrological processes within the Tao River Basin and the method used might be generalized as a reference for future regional-scale eco-hydrological research.展开更多
文摘Aim The several species of the genus Paris called ＂Chonglou＂ are famous traditional Chinese herbal medicines. We established the quantitative analysis method of the steroidal saponins in some species of the genus Paris and discussed their relations. Methods We detected the contents of 11 steroidal saponins in Paris samples with a Kromasel C18 （ 150 mm× 4.6 mm ID, 5μm） column which was subjected to gradient elution with acetonitrile-water （30：70- 60：40, V/V） at a flow rate of 1 mL· min^-1 by HPLC-ELSD and established chemical cluster tree using SPSS 11 software. Results All the samples could be separated and calibration curves of 11 saponins were prepared. We successfully detected the contents of 11 steroidal saponins in 14 Paris spp. in 30 min. The recovery for the assay of saponins was between 95 % and 97 %. The RSD of precision of 11 saponins and stability of samples were below 3 %. Chemical phylogenetic tree based on saponin contents indicated that 17 samples of Paris spp. clustered separately. Conclusion The established method is accurate and convenient, and suitable for the quantitative analysis of these 11 steroidal saponins in Paris spp.. The chemical phylogenetic tree is in accordance with Takhtajian classical taxonomy.
基金Supported by Science and Technology Project of Guizhou province "The Key Technologies and Demonstration of Karst Mountain Low-carbon Rural Tourism Demonstration Area Construction"(SY[2012]3058)Science and Technology Project of Guizhou Province,([2013]2300)~~
文摘[Objective] The aim was to analyze temporal and spatial variation charac- teristics of potential evapotranspiration in Guizhou Province. [Method] According to information from 19 meteorological stations of Guizhou Province from 1960 to 2007, with the formulas of optimizational Penman-Monteith and SEBAL net radiation mod- el, the reference crop evapotranspiration ETo was calculated. Also with the spatial interpolation method of Arcgis 9.3, climate tendency rate statistics, K-M test, wavelet analysis and so on, the related regional differentiation and spatial and temporal change characteristics between meteorological factors from each monitoring station and ETo were analyzed. [Result] The results show that the correlation of potential evapotranspiration and meteorological factors in Guizhou Province demonstrates re- gional differentiation; there was no direct connection between the correlation of po- tential evapotranspiration and meteorological factors and the amount of meteorologi- cal factors in the year; there were 3 cycles in potential evapotranspiration, namely, 1 year, 5 years and 10 years, with 3 mutation points, respectively, in 1965, 1984 and 1999, mainly affected by air temperature, precipitation and solar radiation. [Conclusion] The research is of great significance in developing irrigation approach- es, adjusting agricultural structure and ecological construction.
基金funded by the State Key Development Program for Basic Research of China(973 program,Grant No.2010CB951002)National Natural Science Funds of China(Grant No.40972218)+1 种基金the Natural Sciences Foundation ofChina(Grant No.40871027)the Knowledge Innovation project of Chinese Academy of science(Grant No.KZCX2–YW–334)
文摘The primary purpose of this study was to assess water losses by evapotranspiration, evaporation and seepage in arid zone.Normally, evaporation and seepage are the main causes of water losses.For modeling water losses,a combination of Genetic Programming(GP),Penman-Monteith(PM) and Penman combination model for measurement of evapotranspiration,evaporation and seepage has been developed.The results were found to be varying depending on how the evaporation and seepage phenomena are modeled.These results show that that there is an improvement in reducing evapotranspiration,evaporation and seepage losses in arid and semi-arid region.
基金supported by the National Basic Research Program of China (973 Program, Grant No. 2009CB421406)the National High Technology Research and Development Program of China (863 Program, Grant No. 2009AA122100)
文摘The impact of the interannual variability (IAV) of vegetation on the IAV of evapotranspiration is investigated with the Community Land Model (CLM3.0) and modified Dynamic Global Vegetation Model (DGVM). Two sets of 50-year off-line simulations are used in this study. The simulations begin with the same initial surface-water and heat states and are driven by the same atmospheric forcing data. The vegetation exhibits interannual variability in one simulation but not in the other simulation. However, the climatological means for the vegetation are the same. The IAV of the 50-year annual total evapotranspiration and its three partitions (ground evaporation, canopy evaporation, and transpiration) are analyzed. The global distribution of the evapotranspiration IAV and the statistics of evapotranspiration and its components in different ecosystems show that the IAV of ground evaporation is generally large in areas dominated by grass and deciduous trees, whereas the IAV of canopy evaporation and transpiration is large in areas dominated by bare soil and shrubs. For ground evaporation, canopy evaporation, and transpiration, the changes in IAV are larger than the mean state over most grasslands and shrublands. The study of two sites with the same IAV in the leaf area index (LAI) shows that the component with the smaller contribution to the total evapotranspiration is more sensitive to the IAV of vegetation. The IAV of the three components of evapotranspiration increases with the IAV of the fractional coverage (FC) and the LAI. The ground evaporation IAV shows the greatest increase, whereas the canopy evaporation shows the smallest increase.
文摘Evapotranspiration （ETc） is an important quantity for hydrological cycle. This study shows evapotranspiration, the ratio of evaporation to evapotranspiration （E/ETc） of winter wheat and maize in north China. Several relationships, namely, E/ET0 and soil surface moisture, E/ET0 and leaf area index （LAI）, are also analyzed. The average seasonal ETc values for winter wheat, maize （2008） and maize （2009） are 431.21,456.3 and 341.4mm. The value of E/ET0 varied from 1 at initial growth stage to 0.295 at the later growth for winter wheat, and from 1 to 0.492, from 1 to 0.566 for maize （2008） and maize （2009）. The relationship between E/ET0 and surface soil water content, and E/ET0 and LAI are fitted to a quadratic parabola equation with significant correlation coefficients, respectively, for wheat and maize. These results should help the precise planning and efficient management of irrigation for these crops in this region.
基金supported by the Doctoral Program of China’s Higher Education Research Fund(Grant No.20110211110011)the National Natural Science Foundation of China(Grant Nos.41001014,41240002,51209119)
文摘In a case study in Tao River Basin, China, we derived a high spatial-resolution regional distribution of evapotranspiration(ET) using the single crop coefficient method and Budyko equation. We then further analyzed the spatio-temporal characteristics of this diverse eco-hydrological basin from 2001–2010. The results suggest that the single crop coefficient method based on leaf area index captures better spatial and temporal dynamics of the regional ET than did the Budyko Equation method. The rising temperature was the main reason for the increasing ET in the Tao River Basin during 2001–2010. Areas with high ET efficiency were distributed mainly in the areas where the vegetation coverage was high, and a lower runoff coefficient responded. The estimated spatial patterns of ET allowed an improved understanding of the eco-hydrological processes within the Tao River Basin and the method used might be generalized as a reference for future regional-scale eco-hydrological research.
