高光谱遥感能同时获取地物空间影像和连续且精细的光谱信息,以图谱合一的形式更为精确地描述地物,然而高光谱影像普遍存在同物异谱和同谱异物现象,给准确地物分类带来挑战;激光雷达(light detection and ranging,LiDAR)能够获取地物拓...高光谱遥感能同时获取地物空间影像和连续且精细的光谱信息,以图谱合一的形式更为精确地描述地物,然而高光谱影像普遍存在同物异谱和同谱异物现象,给准确地物分类带来挑战;激光雷达(light detection and ranging,LiDAR)能够获取地物拓扑信息,可用于构建地表三维模型,但单纯采用LiDAR数据无法准确识别地物。基于以上2点,开展高光谱影像和LiDAR数据的融合研究,采用形态学属性剖面进行特征提取,借助稀疏多项式逻辑回归分类器分类,探讨在不同特征组合下的融合与分类效果;并以黑河中游张掖绿洲农业区精细作物分类为目标,采用航空高光谱影像和LiDAR DSM数据对本文方法进行了应用验证。研究表明,该方法可获得精度更高和稳定性更好的分类结果,高光谱与LiDAR融合的方法分类精度最高可达94. 50%。展开更多
A detailed understanding of the composition,buffering capacity,surface charge property,and metals leaching behavior of bauxite residue is the key to improved management,both in reducing the environmental impact and us...A detailed understanding of the composition,buffering capacity,surface charge property,and metals leaching behavior of bauxite residue is the key to improved management,both in reducing the environmental impact and using the material as an industrial by-product for other applications.In this study,physical,chemical,and surface charge properties of bauxite residue derived from a combined process were investigated.Results indicated that the main alkaline solids in bauxite residue were katoite,sodalite,and calcite.These minerals also lead to a higher acid neutralizing capacity of bauxite residue.Acid neutralizing capacity(ANC)to pH 7.0 of this residue is about 0.9 mol H^+/kg solid.Meanwhile,the Fe-,Al-,and Si-containing minerals in bauxite residue resulted in an active surface;The isoelectric point(IEP)and point of zero charge(PZC)were 7.88 and 7.65,respectively.This also leads to a fact that most of the metals in bauxite residue were adsorbed by these surface charged solids,which makes the metals not readily move under natural or even moderately acidic conditions.The leaching behavior of metals as a function of pH indicated that the metals in bauxite residue present low release concentrations(pH>3).展开更多
基金Projects(41501350,41461071,31860170)supported by the National Natural Science Foundation of China
文摘A detailed understanding of the composition,buffering capacity,surface charge property,and metals leaching behavior of bauxite residue is the key to improved management,both in reducing the environmental impact and using the material as an industrial by-product for other applications.In this study,physical,chemical,and surface charge properties of bauxite residue derived from a combined process were investigated.Results indicated that the main alkaline solids in bauxite residue were katoite,sodalite,and calcite.These minerals also lead to a higher acid neutralizing capacity of bauxite residue.Acid neutralizing capacity(ANC)to pH 7.0 of this residue is about 0.9 mol H^+/kg solid.Meanwhile,the Fe-,Al-,and Si-containing minerals in bauxite residue resulted in an active surface;The isoelectric point(IEP)and point of zero charge(PZC)were 7.88 and 7.65,respectively.This also leads to a fact that most of the metals in bauxite residue were adsorbed by these surface charged solids,which makes the metals not readily move under natural or even moderately acidic conditions.The leaching behavior of metals as a function of pH indicated that the metals in bauxite residue present low release concentrations(pH>3).
