Adamsroche7297

The composition, structure and phase transformations occurring on cathode surfaces greatly affect the performance of Li-ion batteries. Li-Ion diffusion and surface-electrolyte interaction are two major phenomena that impact the capacity and cell impedance. The effects of surface reconstruction (SR) of cathode materials on the performance of Li-ion batteries are of current interest. However, the origin and evolution of the SR are still not well understood. In this work, density functional theory (DFT) calculations are used to investigate the processes taking place during surface segregation and reconstruction. Facet dependent segregation was found in Li(Ni1-x-yMnxCoy)O2 (NMC) cathodes. Specifically, Co tends to segregate to the (104) surface of the primary particles within the transition metal layer, while Ni ions tend to segregate to the (012) surface in the Li layer, forming a SR. Experimental evidence shows the SR to be epitaxial with the bulk of the as-synthesized material, and the new SR phase is pinned to the NMC unit cell leading to a strained SR. Here, we show that strain can stabilize a spinel structure of the SR layers. Understanding the effects of surface strain opens a new avenue for the design of cathode materials with enhanced surface properties.An activatable photosensitizer based on methylene blue was developed and validated for its efficacy in the selective killing of γ-glutamyl transpeptidase expressing cells. The 1O2 deactivation via bond breakage, rapid in situ enzymatic photosensitivity conversion, long lysosomal retention, and nucleus relocation collectively contribute to its strong and selective photodynamic effects.Full control of the regioselectivity in the functionalization of fullerenes is important for production of fullerene derivatives with desirable properties. Cycloaddition reactions of C60 usually take place at the hexagon-hexagon ring junction, i.e. the [6,6] bond of the fullerene cage, whereas the [5,6] bond is generally unreactive. The activation of the [5,6] bond toward Diels-Alder reactions is difficult because of its longer bond length than the [6,6] bond. In this study, we computationally demonstrate that the [5,6] bond of C60 can be efficiently activated by encapsulation of a divalent metal atom such as Ca or Sm. Electron transfer from the metal atom to the fullerene cage and the interaction between the metal cation and the cage play critical roles in enhancing the reactivity of the [5,6] bond. The physical origin of the reactivity enchancement of the [5,6] bond is investigated quantitatively by using the activation strain model and the energy decomposition method. The change in the orbital interaction energy along the intrinsic reaction coordinate has a major effect on the thermodynamics and kinetics of the reactions between Ca@C60 and cyclopentadiene. Both mono- and bis-addition reactions of cyclopentadiene with Ca@C60 prefer to take place at the [5,6] bonds of the fullerene cage thermodynamically, which is distinct from the case of pristine C60. The HOMO-LUMO energy gap of Ca@C60 is remarkably enlarged upon mono- and bis-functionalization with cyclopentadienes. Therefore, the covalent derivatization strategy can be used to capture the unconventional, missing metallofullerene M@C60.Mass-dependent diagonal Born-Oppenheimer corrections (DBOCs) to the ab initio electronic ground state potential energy surface for the main 16O3 isotopologue and for homogeneous isotopic substitutions 17O3 and 18O3 of the ozone molecule are reported for the first time. The system being of strongly multiconfigurational character, multireference configuration interaction wave function ansatz with different complete active spaces was used. The reliable DBOC calculations with the targeted accuracy were possible to carry out up to about half of the dissociation threshold D0. The comparison with the experimental band centers shows a significant improvement of the accuracy with respect to the best Born-Oppenheimer (BO) ab initio calculations reducing the total root-mean-squares (calculated-observed) deviations by about a factor of two. For the set of 16O3 vibrations up to five bending and four stretching quanta, the mean (calculated-observed) deviations drop down from 0.7 cm-1 (BO) to about 0.1 cm-1, with the most pronounced improvement seen for bending states and for mixed bending-stretching polyads. In the case of bending band centers directly observed under high spectral resolutions, the errors are reduced by more than an order of magnitude down to 0.02 cm-1 from the observed levels, approaching nearly experimental accuracy. A similar improvement for heavy isotopologues shows that the reported DBOC corrections almost remove the systematic BO errors in vibrational levels below D0/2, though the scatter increases towards higher energies. The possible reasons for this finding, as well as remaining issues are discussed in detail. The reported results provide an encouraging accuracy validation for the multireference methods of the ab initio theory. New sets of ab initio vibrational states can be used for improving effective spectroscopic models for analyses of the observed high-resolution spectra, particularly in the cases of accidental resonances with "dark" states requiring accurate theoretical predictions.Correction for 'Biocompatible nitrogen-doped carbon dots synthesis, characterization, and application' by Yoonsang Park et al., J. Mater. Chem. B, 2020, DOI 10.1039/d0tb01334j.Rapid and environmentally friendly ultrasound-assisted dispersive liquid-liquid microextraction (US-DLLμE) and vortex assisted-emulsification liquid-liquid microextraction (VA-ELLμE) methods are proposed for the speciation of selenium in domestic and mineral water samples. Zunsemetinib solubility dmso A deep eutectic solvent (DES) prepared with different ratios of choline chloride and phenol is used as an extractant for hydrophobic tetravalent Se complexed with diethyldithiocarbamate in different water samples. The total inorganic Se species levels in water samples were determined via reducing Se(vi) to Se(iv), using sodium thiosulphate as a reducing agent. The total Se levels in formula milk and cereal samples were determined after microwave acid digestion. The different heating steps in GFAAS were also optimized. The analytical parameters for US-DLLμE and VA-ELLμE, including pH, the volume of complexing agent, the ultrasound and vortex mixing shaking times, and the volume and composition of the deep eutectic solvent, were optimized. The accuracies of both methods were confirmed based on the analysis of a certified reference material (CRM) BCR 189 (wholemeal flour).