The enthalpies of solution of glycine in aqueous solutions of urea,formamide,acetamide,DMSOand acetone were measured at298.15 K by a RD496-Ⅲ microcalorimeter.The transfer enthalpies(ΔtrH) ofglycine from water to aqu...The enthalpies of solution of glycine in aqueous solutions of urea,formamide,acetamide,DMSOand acetone were measured at298.15 K by a RD496-Ⅲ microcalorimeter.The transfer enthalpies(ΔtrH) ofglycine from water to aqueous organic mixtures were derived and interpreted qualitatively with structural hydra-tion interaction model.The results suggest that hydrophilic-hydrophilic interaction between glycine and cosol-vent molecule gives a negative contribution to the transfer enthalpies of glycine,while the hydrophilic hydro-phobic interaction makes a positive contribution.The relative position ofΔtrH-composition profiles viz.urea <formamide <0 <acetamide <DMSO<acetone,characterizes the hydrophobicity or hydrophilicity of the cosol-vent molecule and correctly reflectes the solute-solvent interaction in the transfer process.展开更多
湖泊面积及空间分布是表征水情变化的重要指示因子,对研究气候变化和人类活动对水资源的影响具有重要作用。如何利用遥感影像进行湖泊制图和面积估算是当前遥感应用研究中的难点问题。从实际应用需求出发,采用GF-1/WFV(Wide Field View)...湖泊面积及空间分布是表征水情变化的重要指示因子,对研究气候变化和人类活动对水资源的影响具有重要作用。如何利用遥感影像进行湖泊制图和面积估算是当前遥感应用研究中的难点问题。从实际应用需求出发,采用GF-1/WFV(Wide Field View)、Landsat-8 OLI(Operational Land Imager)、MODIS(Moderate-Resolution Image Spectroradiometer)遥感数据,选用安徽省受人类活动影响较大的54个湖泊为研究区域,采用NDWI二值分割法得到湖泊水体信息,使用30,500 m和1 000 m 3种空间分辨率的遥感影像进行湖泊制图,探讨制图精度与湖泊形态之间的关系。结果表明:湖泊分形维数值越大,湖泊形态越复杂, Kappa系数越高,面积误差越小;遥感影像分辨率越高,湖泊制图结果的Kappa系数和总体精度越高。展开更多
文摘The enthalpies of solution of glycine in aqueous solutions of urea,formamide,acetamide,DMSOand acetone were measured at298.15 K by a RD496-Ⅲ microcalorimeter.The transfer enthalpies(ΔtrH) ofglycine from water to aqueous organic mixtures were derived and interpreted qualitatively with structural hydra-tion interaction model.The results suggest that hydrophilic-hydrophilic interaction between glycine and cosol-vent molecule gives a negative contribution to the transfer enthalpies of glycine,while the hydrophilic hydro-phobic interaction makes a positive contribution.The relative position ofΔtrH-composition profiles viz.urea <formamide <0 <acetamide <DMSO<acetone,characterizes the hydrophobicity or hydrophilicity of the cosol-vent molecule and correctly reflectes the solute-solvent interaction in the transfer process.
文摘湖泊面积及空间分布是表征水情变化的重要指示因子,对研究气候变化和人类活动对水资源的影响具有重要作用。如何利用遥感影像进行湖泊制图和面积估算是当前遥感应用研究中的难点问题。从实际应用需求出发,采用GF-1/WFV(Wide Field View)、Landsat-8 OLI(Operational Land Imager)、MODIS(Moderate-Resolution Image Spectroradiometer)遥感数据,选用安徽省受人类活动影响较大的54个湖泊为研究区域,采用NDWI二值分割法得到湖泊水体信息,使用30,500 m和1 000 m 3种空间分辨率的遥感影像进行湖泊制图,探讨制图精度与湖泊形态之间的关系。结果表明:湖泊分形维数值越大,湖泊形态越复杂, Kappa系数越高,面积误差越小;遥感影像分辨率越高,湖泊制图结果的Kappa系数和总体精度越高。
