X-ray Diffraction Study of Structural Changes in High-Strength Ceramics Based on Zirconium Oxide with Additions of Ytterbium and Neodymium Oxides after Hydrothermal Treatment

Crystallography Reports - A surface structural analysis of two ceramic samples of zirconium oxide (ZrO2) sintered at 1550°C, stabilized in the tetragonal form, before and after hydrothermal...     

Structural Investigations of RNA–Protein Complexes in Post-Ribosomal Era

Crystallography Reports - Structural studies of RNA–protein complexes are important for understanding many molecular mechanisms occurring in cells (e.g., regulation of protein synthesis and...     

Calixarenes functionalized with phosphine oxide and diamide functions as extractants and ionofores for rare-earth metals

Calixarene-based ligands with phosphine oxide and diamide functions at wide and narrow rims are synthesized and studied as extracting agents for liquid extraction and ionophores for polymeric electrochemical ion sensors. Calixarene ligands are compared with corresponding phosphine oxide and diamide ligands which are not attached to the calixarene platform. Extraction and sensor properties of the ligands were studied in different metal ion solution with special attention paid to rare-earth metals. Attachment of phosphine oxide groups to the calixarene platform leads to the sharp increase of both extraction and sensing ability of the corresponding systems comparing to non-bonded phosphine oxide. In case of the diamide derivatives attached to the calixarene performance of corresponding ligands was similar to those of non-bonded diamides.     

Erratum to:Structural Investigations of RNA–Protein Complexes in Post-Ribosomal Era

Crystallography Reports - An Erratum to this paper has been published: https://doi.org/10.1134/S1063774521340095     

Structure of a Mutant Form of Translation Regulator Hfq with the Extended Loop L4

Crystallography Reports - The bacterial protein Hfq is a member of a large family of Lsm proteins, which are characterized by a conserved tertiary structure and form a stable ring-shaped quaternary...     

Ethanol dehydrogenation on copper catalysts with ytterbium stabilized tetragonal ZrO<Subscript>2</Subscript> support

The physicochemical and catalytic properties of Cu-containing crystalline zirconia, obtained via sol–gel synthesis in the presence of Yb³⁺ ions and polyvinylpyrrolidone, are studied. DTG/DSC, TEM, XRD and BET methods are used to analyze the crystallization, texture, phase uniformity, surface and porosity of ZrO₂ nanopowders. It is shown that increasing the copper content (1, 3, and 5 wt % from ZrO₂) raises the dehydrogenation activity in the temperature range of 100–400°C and lowers the activation energy of acetaldehyde formation. It is found that the activity of all Cu/t-ZrO₂ catalysts grows under the effects of the reaction medium, due to the migration and redispersion of copper.