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搜索结果: 1-15 共查到理学 Ferrihydrite相关记录25条 . 查询时间(0.062 秒)
The reduction of less stable ferric hydroxides and formation of ferrous phases is critical for the fate of phosphorus in anaerobic soils and sediments. The interaction between ferrous iron and phospha...
We show that the coercive field in ferritin depends on the maximum magnetic field in a ysteresis loop and that coercivity and loop shifts depend both on the maximum and cooling fields. The time depend...
Fe(III)盐为原料、NaOH为沉淀剂、采用三种方法调控制备了ferrihydrite, 借助X射线衍射(XRD)、红外光谱(IR)、差热分析(DTA)及其在稀盐酸中的溶解速率等手段对其结构进行了表征, 探讨了ferrihydrite的形成环境对其亚微观结构及其反应活性的影响. 结果表明, 不同方法制备的ferrihydrite的亚微观结构不同, 恒pH条件下制备的ferrihydrite结构...
Abstract: High-resolution transmission electron microscopy (HRTEM), selected-area electron diffraction (SAED), annular dark-field scanning transmission electron microscope (STEM) images, and electron ...
Abstract: The distribution and chemical state of Si in a synthetic 2-line ferrihydrite with a Si/(Si + Fe) molar ratio of 0.11 was studied. Heat treatment under oxidizing conditions shows that Si-rich...
Abstract: Iron oxides in surface environments generally form at temperatures of 25 ?10癈, but synthesis experiments are usually done at higher temperatures to increase the rate of crystallization. To m...
Abstract: The effects of neodymium (Nd) on the transformation of ferrihydrite to iron oxides was studied. The possible isomorphous substitution of Nd3+ for Fe3+ in iron oxides was examined also. Nd wa...
Abstract: We investigated the crystallization of ferrihydrite prepared by hydrolysis of Fe(NO3)3 solutions containing phosphate. Crystallization was studied at different pH (3–9), temperatures (298, 3...
Abstract: Minerals in surface environments form in both turbulent and non-turbulent systems. This study compares the properties of Al goethite formed from ferrihydrite at 60 °C in 0.3 M KOH with and w...
Abstract: A structural model for the geometry of Fe(III) octahedra near the surface of finely divided ferrihydrite was elaborated based on the bond梫alence theory and by considering the interaction of ...
X-ray absorption fine structure (XAFS) spectra were collected on a series of ferrihydrite samples prepared over a range of precipitation and drying conditions. Analysis of the XAFS pre-edge structures...
Abstract: Two-line ferrihydrite is an important adsorbent of many toxics in natural and anthropogenic systems; however, the specific structural sites responsible for the high adsorption capacity are n...
X-ray diffraction of four natural samples of ferrihydrite indicates the presence of crystalline domains within the primary particles. The average diameter of the primary particles (determined from low...
Color variations from brown to yellow of synthesized goethite have been studied colorimetrically and spectroscopically. Goethite with various colors was synthesized at pH 13 and 40°C by varying the in...
57Fe M鰏sbauer spectra of two synthetic samples of ferrihydrite, recorded at 4.2 K in applied fields of up to 9 T, have been analysed by a mean-field model. The samples exhibit two and six X-ray diffra...

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