本文引用了许多新的研究资料,阐明剖析土壤矿物的重要性,并强调必须应用先进技术,例如高分辨透射(扫描)电镜、能谱分析、电子衍射和 X 光衍射分析等,深入研究土壤体系。这些方法可在超微[mm(10^(-3)m)-nm(10^(-9)m)]范围内,直接形象地...本文引用了许多新的研究资料,阐明剖析土壤矿物的重要性,并强调必须应用先进技术,例如高分辨透射(扫描)电镜、能谱分析、电子衍射和 X 光衍射分析等,深入研究土壤体系。这些方法可在超微[mm(10^(-3)m)-nm(10^(-9)m)]范围内,直接形象地观察土壤中矿物结晶形貌、大小、结构以及它们之间的相互排列和结合状态,并可进行单晶和晶粒间的微区成分分析。因土壤由不同结构类型的粘粒矿物组成,其矿物活性差异很大,可直接影响土壤的比表面、阳离子交换量、离子的吸附和解吸等土壤性质,因此,对土壤中各级矿物尤其<2μm的矿物进行剖析,可揭示土壤胶体和晶粒表面与溶液离子、微生物、植物根系、肥料、污染物间相互作用的机理,有利于进一步探索土壤矿物对生产力及管理措施的影响。文章还对矿物剖析的应用前景作了高度评价。展开更多
The sorption of AuCL4- ,AuCl2- and Au(S2O3)23- on δ-MnO2 was investigated at pH2-11.6, 0.01 mol/L and 0.1 mol/L NaNO3 solutions. At pH 4 in two electrolyte strength solutions, Au sorption densities on δ-MnO2 are 0. ...The sorption of AuCL4- ,AuCl2- and Au(S2O3)23- on δ-MnO2 was investigated at pH2-11.6, 0.01 mol/L and 0.1 mol/L NaNO3 solutions. At pH 4 in two electrolyte strength solutions, Au sorption densities on δ-MnO2 are 0. 18-0.21 and 0.28 μmoL/m2 for AuCl4 and Au(S2O3)23- , respectively, and the Au surface coverage is approximate to or lower than 1 % . This adsorption of the two Au complexes decreases as the solution pH increases, which conforms to the sorption regularity of the anion on δ-MnO2. The Au sorption decreases in the sequence of Au(S2O3)23- >AuCl4- > AuCl2- . The intrinsic equilibrium constants (logKint) of the three Au complexes are 1.17-2.7, much higher than those of Cu and Cd. The hydrolysis products of AuCLi are preferentially adsorbed by δ-MnO2 and the inner-sphere Au-surface complexes are formed on the surface.展开更多
文摘本文引用了许多新的研究资料,阐明剖析土壤矿物的重要性,并强调必须应用先进技术,例如高分辨透射(扫描)电镜、能谱分析、电子衍射和 X 光衍射分析等,深入研究土壤体系。这些方法可在超微[mm(10^(-3)m)-nm(10^(-9)m)]范围内,直接形象地观察土壤中矿物结晶形貌、大小、结构以及它们之间的相互排列和结合状态,并可进行单晶和晶粒间的微区成分分析。因土壤由不同结构类型的粘粒矿物组成,其矿物活性差异很大,可直接影响土壤的比表面、阳离子交换量、离子的吸附和解吸等土壤性质,因此,对土壤中各级矿物尤其<2μm的矿物进行剖析,可揭示土壤胶体和晶粒表面与溶液离子、微生物、植物根系、肥料、污染物间相互作用的机理,有利于进一步探索土壤矿物对生产力及管理措施的影响。文章还对矿物剖析的应用前景作了高度评价。
基金Project supported by the National Studying-abroad Foundation, the National Natural Science Foundation of China (Grant No. 49573200) and the Australian Mining Industry.
文摘The sorption of AuCL4- ,AuCl2- and Au(S2O3)23- on δ-MnO2 was investigated at pH2-11.6, 0.01 mol/L and 0.1 mol/L NaNO3 solutions. At pH 4 in two electrolyte strength solutions, Au sorption densities on δ-MnO2 are 0. 18-0.21 and 0.28 μmoL/m2 for AuCl4 and Au(S2O3)23- , respectively, and the Au surface coverage is approximate to or lower than 1 % . This adsorption of the two Au complexes decreases as the solution pH increases, which conforms to the sorption regularity of the anion on δ-MnO2. The Au sorption decreases in the sequence of Au(S2O3)23- >AuCl4- > AuCl2- . The intrinsic equilibrium constants (logKint) of the three Au complexes are 1.17-2.7, much higher than those of Cu and Cd. The hydrolysis products of AuCLi are preferentially adsorbed by δ-MnO2 and the inner-sphere Au-surface complexes are formed on the surface.
