从典型地物光谱曲线分析入手,MODIS数据的第7、2、1波段对植被、陆地、水体区分明显。本文对长三角太湖流域地区,采用MODIS数据以五种常水体识别进行水体信息提取,然后分别从目视解译效果、水体区分度的计算和提取的水体面积三方面来对...从典型地物光谱曲线分析入手,MODIS数据的第7、2、1波段对植被、陆地、水体区分明显。本文对长三角太湖流域地区,采用MODIS数据以五种常水体识别进行水体信息提取,然后分别从目视解译效果、水体区分度的计算和提取的水体面积三方面来对这五种指数方法进行比较和评价。结果表明,在应用MODIS数据进行水体识别时,比值植被指数(RVI,Ratio Vegetation Index)和混和水体指数(CIWI,Combined Index of Normalized Difference Water Index)模型的目视解译效果较好,且CIWI指数具有水陆区分度较大和水体面积提取精度较高的优点。展开更多
Triacontyl modified silica gel as a sorbent coupled with gas chromatography-mass spectrometry(GC-MS) was developed to determine EPA prior 16 polycyclic aromatic hydrocarbons(PAHs) in water samples.Various parameters o...Triacontyl modified silica gel as a sorbent coupled with gas chromatography-mass spectrometry(GC-MS) was developed to determine EPA prior 16 polycyclic aromatic hydrocarbons(PAHs) in water samples.Various parameters of solid-phase extraction such as organic modifier solvent,eluent,sample flow rate and volume were optimized.The developed method was found to yield a linear calibration curve in the concentration range of 0.05-8μg/L with respect to naphthalene,acenaphthylene,acenaphthene and 0.01-8μg/L for dibenz[a,h]anthracene and 0.05-14μg/L for fluorene,phenanthrene,anthracene and 0.01-14μg/L for the rest of analytes.Furthermore,the good accuracy and repeatability of the method made sure the requirements for achieving reliable analysis of PAHs in the environmental water samples,and the recoveries of optimal method were in the range of 80-120%except to higher volatility PAHs.C_(30)-bonded silica was proved to be an efficient sorbent for extraction of high molecular weight PAHs.展开更多
文摘从典型地物光谱曲线分析入手,MODIS数据的第7、2、1波段对植被、陆地、水体区分明显。本文对长三角太湖流域地区,采用MODIS数据以五种常水体识别进行水体信息提取,然后分别从目视解译效果、水体区分度的计算和提取的水体面积三方面来对这五种指数方法进行比较和评价。结果表明,在应用MODIS数据进行水体识别时,比值植被指数(RVI,Ratio Vegetation Index)和混和水体指数(CIWI,Combined Index of Normalized Difference Water Index)模型的目视解译效果较好,且CIWI指数具有水陆区分度较大和水体面积提取精度较高的优点。
基金supported by the National Natural Science Foundation of China(No.20775042)the Research Fund for the Doctoral Program of Higher Education(No.20070003026)
文摘Triacontyl modified silica gel as a sorbent coupled with gas chromatography-mass spectrometry(GC-MS) was developed to determine EPA prior 16 polycyclic aromatic hydrocarbons(PAHs) in water samples.Various parameters of solid-phase extraction such as organic modifier solvent,eluent,sample flow rate and volume were optimized.The developed method was found to yield a linear calibration curve in the concentration range of 0.05-8μg/L with respect to naphthalene,acenaphthylene,acenaphthene and 0.01-8μg/L for dibenz[a,h]anthracene and 0.05-14μg/L for fluorene,phenanthrene,anthracene and 0.01-14μg/L for the rest of analytes.Furthermore,the good accuracy and repeatability of the method made sure the requirements for achieving reliable analysis of PAHs in the environmental water samples,and the recoveries of optimal method were in the range of 80-120%except to higher volatility PAHs.C_(30)-bonded silica was proved to be an efficient sorbent for extraction of high molecular weight PAHs.
