Crystal structures of HgBa2CaCu206 + ~ (Hg1212 ) and HgBa2Ca2Cu308 + a (Hg1223 ) have been determined on single crystals at room temperature conditions by X-ray diffraction techniques. Both tetragonal specimens are isomorphous with compounds in the T1-Ba-Ca-Cu-O system. We observe excess oxygen in both samples on two sites near the z=0 plane: at (1⁄200) and close to (1⁄2, 0.4, 0) but no oxygen ...

The native anomalous phasing method will have greatest application to cases where poor occupancy or multiple substitution occurs, making direct interpretation of isomorphous difference Pattersons difficult. Alternatively, this method may be useful for locating relative origins for the binding sites from several derivatives in unfavorable space groups, such as P1. The major reasons for the succe...

A series of mesoporous silicas impregnated with nanocrystalline sulphated zirconia was prepared by a sol-gel process using an ionic liquid-templated route. The physicochemical properties of the mesoporous sulphated zirconia materials were studied using characterisation techniques such as inductively coupled optical emission spectroscopy, X-ray diffraction, transmission electron microscopy, ener...

The ferrite process is an established method for treating wastewaters containing dissolved toxic metals, using precipitation at temperatures above 65 °C. Various ambient-temperature operation methodologies have also been proposed, but the effects of temperature reduction on product stability, and on the extent of isomorphous substitution (in terms of x in Me(x)Fe(3-x)O(4), Me representing a non...

Cadmium (Cd) isotopes have great potential for understanding Cd geochemical cycling in soil and aquatic systems. Iron (oxyhydr)oxides can sequester via adsorption isomorphous substitution, but how these interactions affect isotope fractionation remains unknown. Here, we show that preferentially enriches lighter on iron (oxyhydr)oxide surfaces through equilibrium fractionation, with a similar ma...

Cumulative biomicroscopic evidence is usually sufficient for the diagnosis of recurrent corneal erosion or bullous keratopathy, however, exploration of the disease pathogenesis requires subcellular-level visualization of corneal structure. In the current study, lanthanoid staining and scanning electron microscopy were employed to visualize quite a number of structures responsible for epithelium...