Prior research has not systematically investigated the enablers and inhibitors in conjunction to measure consumer behavior toward mobile wallets (m-wallets), focusing either on the adoption or the ...resistance perspective only. Similarly, antecedents and consequences of the dichotomous nature of word of mouth for m-wallets have also remained obscure so far. The present research proposes to address this void in the accumulated learnings by examining both enablers and inhibitors of mobile wallets (m-wallets) as antecedents of valence of word of mouth (positive and negative; PWOM and NWOM, respectively). Grounded in Dual Factor Theory, this study aims to explore consumers’ continued use intentions resulting from the WOM valence. The findings reveal that enablers (perceived information quality, perceived ability, and perceived benefit) drive PWOM, while the inhibitors (perceived cost, perceived risk, and perceived uncertainty) spur NWOM. Furthermore, the results show that only PWOM drives the continuance intentions of m-wallet users. Therefore, the study proves that the antecedents of PWOM are different from those of NWOM.
•Enablers and inhibitors of mobile wallets (m-wallet) use examined as antecedents of the valence of word of mouth (WOM).•Dual factor theory used to ground the conceptual propositions.•Effect of positive WOM(PWOM) and negative WOM(NWOM) on continued intention to use m-wallets examined.•Results show a positive association of enablers with PWOM and inhibitors with NWOW.•PWOM is positively associated with continued intentions to use m-wallets.
Understanding the electronic structures of high‐valent metal complexes aids the advancement of metal‐catalyzed cross coupling methodologies. A prototypical complex with formally high valency is ...Cu(CF3)4− (1), which has a formal Cu(III) oxidation state but whose physical analysis has led some to a Cu(I) assignment in an inverted ligand field model. Recent examinations of 1 by X‐ray spectroscopies have led previous authors to contradictory conclusions, motivating the re‐examination of its X‐ray absorption profile here by a complementary method, resonant diffraction anomalous fine structure (DAFS). From analysis of DAFS measurements for a series of seven mononuclear Cu complexes including 1, here it is shown that there is a systematic trifluoromethyl effect on X‐ray absorption that blue shifts the resonant Cu K‐edge energy by 2–3 eV per CF3, completely accounting for observed changes in DAFS profiles between formally Cu(III) complexes like 1 and formally Cu(I) complexes like (Ph3P)3CuCF3 (3). Thus, in agreement with the inverted ligand field model, the data presented herein imply that 1 is best described as containing a Cu(I) ion with dn count approaching 10.
The electronic structures of Cu(CF3)4− and other Cu−CF3 complexes are (re−)evaluated using resonant X‐ray diffraction methods. A systematic trend was identified by which each additional CF3 ligand shifts the resonant Cu K‐edge energy by 2–3 eV, completely accounting for observed differences between complexes with different formal oxidation states. The recently debated assignment of Cu(CF3)4− as containing a Cu(I) ion is, thus, verified.
A2B′B″O6 perovskites: A review Vasala, Sami; Karppinen, Maarit
Progress in solid state chemistry,
20/May , Volume:
43, Issue:
1-2
Journal Article
Peer reviewed
The B-site substituted perovskite oxides A2B′B″O6 have in the recent decades gained an increasing amount of interest due to their various interesting properties and possible applications. Here we ...survey the literature for ca. one thousand A2B′B″O6 perovskite compounds. Crystal structures and the various crystal chemistry features such as ordering and valence mixing of the B cations characteristic to these compounds are reviewed, together with their electronic and magnetic properties. Most importantly, the thorough examination of the research so far carried out allows us to make predictions for a number of new A2B′B″O6 compounds yet to be synthesized and reveal exciting but not yet fully explored puzzles related to this family of functional oxide materials.
The current meta-analysis examined the effects of valence and arousal on source memory accuracy, including the identification of variables that moderate the magnitude and direction of those effects. ...Fifty-three studies, comprising 85 individual experiments (N = 3,040 participants), were selected. Three separate analyses focusing on valence effects (valence-based: negative-neutral; positive-neutral; negative-positive) and other three focusing exclusively on arousal (arousal-based: high-low; medium-low; high-medium) were considered. Effect sizes varied from very small to medium. For the valence-based analyses, source memory accuracy was impaired for emotional compared with neutral stimuli (dunb = −.14 for negative-neutral; dunb = −.11 for positive-neutral), with a similar performance found for the negative-positive comparison (dunb = −.04). In the case of arousal-based analyses, source memory was improved for stimuli with high and medium arousal versus low arousal (dunb = .27, dunb = .49, respectively), with no statistically significant difference between high and medium arousal stimuli (dunb = −.12). Emotion effects on source memory were modulated by methodological factors. These factors may account for the variety findings typically found in emotion-related source memory research and could be systematically addressed in future studies.
X‐ray diffractometer with Rietveld refinement and Raman spectroscopy were used for phase analysis. Ca doping results in decreased εr (24.09–21.52), Q × f (68 914–40 110 GHz), and τf (−50.0 ppm/°C to ...−60.2 ppm/°C) all decrease, which obviously does not conform to the mutual constraint relationship among the three parameters of microwave dielectric properties. The εr of Ce1−xCaxO2−x ceramics is affected by the ion polarizability and the Ce rattling and valence states, among which the rattling of Ce cations plays a dominant role. The presence of oxygen vacancies in Ce1−xCaxO2−x ceramics explains the decrease in Q × f. The τε, εr, and αL are responsible for the decrease in τf, especially for the ταm‐3αL values.
Construction of bifunctional catalysts with balanced adsorption toward multiple reactants and intermediates is crucial for efficient urea‐assisted water splitting. Nickel Sulfide (NiS) is considered ...as a promising choice for both urea oxidation reaction (UOR) and hydrogen evolution reaction (HER), whereas the highly occupied d orbital of Ni sites results in too weak reactant adsorption to achieve satisfactory bifunctionality. Herein, considering the adsorption‐energy scaling limitations, another Mo4+ site with empty d orbital is introduced into NiS crumpled nanoflowers as a reactant mediator for accelerated urea electrolysis. Based on the in situ characterizations and theoretical calculations, a dual‐center catalytic mechanism is proposed that the Mo4+ sites govern the reactant adsorption, subsequently cooperate with nearby Ni sites to promote the reactant dissociation, intermediate formation, and product desorption. The crumpled flower‐like nanostructure also provides abundant active sites and rapid mass transfer. Consequently, the Mo‐NiS exhibits excellent UOR/HER bifunctionality in an anion‐exchange membrane (AEM) flow electrolyzer. Compared with the pure‐water electrolysis system, the urea‐assisted water electrolyzer saves 15% energy to produce hydrogen. Besides, this electrolyzer obtains an ampere‐level current density of 1 A cm−2 at the cell voltage of 2.0 V, about 2.56 times higher than that of the assembly of RuO2||Pt/C, and robust durability.
The low‐valence Mo4+‐doped NiS with crumpled nanoflower‐like structure is constructed for urea‐assisted water splitting. The introduced Mo4+ as the reactant mediator cooperates with Ni sites to accelerate the reaction kinetics, while the crumpled nanoflowers provide abundant active sites and rapid mass transfer, thus achieving efficient electrolysis.
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•The relationship between MnIV and peroxymonosulfate (PMS) activation was established for the first time.•The high MnIV content in nano-octahedra owns high catalytic activity for PMS ...activation.•The PMS activation should mainly occur in the transformation of MnIV/MnIII.
The transformation among MnII, MnIII and MnIV on the surface of the manganese oxides is a critical factor for peroxymonosulfate (PMS) activation. In this work, three kinds of Mn3O4 with different shapes (plate, cube and octahedra) were prepared to tune the surface Mn valence for ciprofloxacin (CIP) degradation, and the relationship between MnIV and PMS activation was established for the first time. The octahedral Mn3O4 (Mn3O4-O) owns high catalytic activity, MnIV is the primary active site on the surface of Mn3O4 for PMS activation to generate the active radicals, while the surface –OH groups play a key role in the formation of reactive intermediates. The quenching experiments and Electron paramagnetic resonance (EPR) results suggest that the SO4− and OH radicals are the main reactive radicals in the catalytic process. The PMS activation should mainly occur in the transformation from MnIV to MnIII. This work is expected to elucidate the relationship between surface valence in manganese oxides and PMS activation by morphology-tuning.
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