Subsurface oxygen has been proposed to be crucial in oxide‐derived copper (OD‐Cu) electrocatalysts for enhancing the binding of CO intermediates during CO2 reduction reaction (CO2RR). However, the ...presence of such oxygen species under reductive conditions still remains debated. In this work, the existence of subsurface oxygen is validated by grazing incident hard X‐ray photoelectron spectroscopy, where OD‐Cu was prepared by reduction of Cu oxide with H2 without exposing to air. The results suggest two types of subsurface oxygen embedded between the fully reduced metallic surface and the Cu2O buried beneath: (i) oxygen staying at lattice defects and/or vacancies in the surface‐most region and (ii) interstitial oxygen intercalated in metal structure. This study adds convincing support to the presence of subsurface oxygen in OD‐Cu, which previously has been suggested to play an important role to mitigate the σ‐repulsion of Cu for CO intermediates in CO2RR.
Subsurface oxygen has been proposed to be crucial for oxide‐derived copper (OD‐Cu) in electrochemical CO2 reduction. In this work, a high‐resolution spectral feature of subsurface oxygen in OD‐Cu was observed by in situ grazing incident hard X‐ray photoelectron spectroscopy. Two types of subsurface oxygen were identified: oxygen staying at lattice defects (in green) and interstitial oxygen intercalated in metal structure (in blue).
Spinel Co3O4, comprising two types of cobalt ions: one Co2+ in the tetrahedral site (Co2+ Td) and the other two Co3+ in the octahedral site (Co3+ Oh), has been widely explored as a promising oxygen ...evolution reaction (OER) catalyst for water electrolysis. However, the roles of two geometrical cobalt ions toward the OER have remained elusive. Here, we investigated the geometrical-site-dependent OER activity of Co3O4 catalyst by substituting Co2+ Td and Co3+ Oh with inactive Zn2+ and Al3+, respectively. Following a thorough in operando analysis by electrochemical impedance spectroscopy and X-ray absorption spectroscopy, it was revealed that Co2+ Td site is responsible for the formation of cobalt oxyhydroxide (CoOOH), which acted as the active site for water oxidation.
Recent years have witnessed increasing interest in the solution‐phase synthesis of atomically precise thiolate‐protected gold clusters (Aux); nonetheless, research on the photocatalytic properties of ...Aux–semiconductor nanocomposites is still in its infancy. In this work, recently developed glutathione‐capped gold clusters and highly ordered nanoporous layer‐covered TiO2 nanotube arrays (NP‐TNTAs) are employed as nanobuilding blocks for the construction of a well‐defined Aux/NP‐TNTA heterostructure via a facile electrostatic self‐assembly strategy. Versatile photocatalytic performances of the Aux/NP‐TNTA heterostructure which acts as a model catalyst, including photocatalytic oxidation of organic pollutant, photocatalytic reduction of aromatic nitro compounds and photoelectrochemical (PEC) water splitting under simulated solar light irradiation, are systematically exploited. It is found that synergistic interaction stemming from monodisperse coverage of Aux clusters on NP‐TNTAs in combination with hierarchical nanostructure of NP‐TNTAs reinforce light absorption of Aux/NP‐TNTA heterostructure especially within visible region, hence contributing to the significantly enhanced photocatalytic and PEC water splitting performances. Moreover, photocatalytic and PEC mechanisms over Aux/NP‐TNTA heterostructure are elucidated and corresponding reaction models were presented. It is anticipated that this work could boost new insight for photocatalytic properties of metal‐cluster‐sensitized semiconductor nanocomposites.
A well‐defined heterostructure consisting of monodisperse Au clusters and hierarchically ordered nanoporous TiO2 nanotube arrays (Aux/NP‐TNTAs) is fabricated via a facile two‐step anodization approach combined with efficient electrostatic self‐assembly. The hierarchically ordered Aux/NP‐TNTA heterostructure demonstrates versatile photocatalytic redox and photoelectrochemical performances under simulated solar light irradiation under ambient conditions.
The benefits of using social network sites (SNS) have spurred heated debate in academia and popular culture alike. This study sought to address the debate by formulating a new, nuanced framework ...highlighting two conceptual distinctions: (a) preference for versus problem in one's interpersonal relations, and (b) SNS use versus the benefits of such use. Mixed-effects meta-analysis was performed in 178 independent samples from seven regions worldwide (n = 108,068; age range = 13-68). Eligible studies were those that examined an association between at least one common proxy measure of the socially rich (vs. poor; i.e., extraversion, social anxiety, or loneliness) and a criterion measure (i.e., SNS use or online social capital). The results revealed a complex picture. SNS use was positively correlated with both extraversion and social anxiety, although the social anxiety-SNS use correlation was significant for adult samples rather than adolescent samples. Online social capital was positively correlated with extraversion but inversely correlated with loneliness. Our conclusion is that extraverted individuals use SNS to enhance their opportunities for social interactions and can acquire more online social resources, whereas adults who are socially anxious use SNS to compensate for their social deficits but such effort is unrelated to online social resource accumulation. Individuals who feel lonely tend to obtain few such resources. However, most of the studies examined the leisure use of Facebook. We advocate more thorough testing of our hypotheses in future research on therapeutic SNS use and/or the use of SNS other than Facebook.
Public Significance Statement
Scholars and social critics have been debating whether social network sites are of greater benefit to those who acquire more or less social resources in face-to-face interactions. This meta-analysis seeks to inform the debate by proposing a nuanced perspective that differentiates between preference for and problem in interpersonal relations, and between social network site use and the benefits of such use.
Semiconductor‐based photocatalysis and photoelectrocatalysis have received considerable attention as alternative approaches for solar energy harvesting and storage. The photocatalytic or ...photoelectrocatalytic performance of a semiconductor is closely related to the design of the semiconductor at the nanoscale. Among various nanostructures, one‐dimensional (1D) nanostructured photocatalysts and photoelectrodes have attracted increasing interest owing to their unique optical, structural, and electronic advantages. In this article, a comprehensive review of the current research efforts towards the development of 1D semiconductor nanomaterials for heterogeneous photocatalysis and photoelectrocatalysis is provided and, in particular, a discussion of how to overcome the challenges for achieving full potential of 1D nanostructures is presented. It is anticipated that this review will afford enriched information on the rational exploration of the structural and electronic properties of 1D semiconductor nanostructures for achieving more efficient 1D nanostructure‐based photocatalysts and photoelectrodes for high‐efficiency solar energy conversion.
One‐dimensional nanostructured photocatalysts and photoelectrodes are reviewed in a comprehensive manner. The basic principles of photocatalysis and photoelectrocatalysis, strategies for improving the photocatalytic and photoelectrochemical water splitting performances of 1D semiconductors, and applications of 1D semiconductors in these two fields are elucidated. Moreover, the challenges and perspectives for achieving full potential of 1D nanostructures are discussed.
Background
Whether non–vitamin K antagonist oral anticoagulants (NOACs) are superior to warfarin among Asians with nonvalvular atrial fibrillation remains unclear.
Methods and Results
In this ...nationwide retrospective cohort study collected from Taiwan National Health Insurance Research Database, there were 5843, 20 079, 27 777, and 19 375 nonvalvular atrial fibrillation patients taking apixaban, dabigatran, rivaroxaban and warfarin, respectively, from June 1, 2012 to December 31, 2016. Propensity‐score weighting was used to balance covariates across study groups. Patients were followed until the first occurrence of any efficacy or safety outcome or the end date of study. Hazard ratios (95% confidence intervals) comparing apixaban, dabigatran, and rivaroxaban with warfarin were: ischemic stroke/systemic embolism (IS/SE), 0.55 (0.43–0.69), 0.82 (0.68–0.98), and 0.81 (0.67–0.97); major bleeding, 0.41 (0.31–0.53), 0.65 (0.53–0.80), and 0.58 (0.46–0.72); and all‐cause mortality, 0.58 (0.51–0.66), 0.61 (0.54–0.68), and 0.57 (0.51–0.65). A total of 3623 (62%), 17 760 (88%), and 26 000 (94%) patients were taking low‐dose apixaban (2.5 mg twice daily), dabigatran (110 mg twice daily), and rivaroxaban (10–15 mg once daily), respectively. Similar to all‐dose NOACs, all low‐dose NOACs had lower risk of IS/SE, major bleeding, and mortality when compared with warfarin. In contrast to other standard‐dose NOACs, apixaban was associated with lower risks of IS/SE (0.45 0.31–0.65), major bleeding (0.29 0.18–0.46), and mortality (0.23 0.17–0.31) than warfarin.
Conclusions
All NOACs were associated with lower risk of IS/SE, major bleeding, and mortality compared with warfarin in the largest real‐world practice among Asians with nonvalvular atrial fibrillation. All low‐dose NOACs had lower risk of IS/SE, major bleeding, and mortality when compared with warfarin. Standard‐dose apixaban caused a lower risk of IS/SE, major bleeding, and mortality compared with warfarin.
The characteristics of magnetic reconnection with a finite x‐line length are studied using three‐dimensional (3D) particle‐in‐cell (PIC) simulations. We simulate two cases: anti‐parallel reconnection ...and guide field reconnection. In both cases, reconnection is triggered by an initial perturbation that is localized in the current direction, and then, an active reconnection region extending around 20 ion inertia length along the current direction is developed. In both cases, the electron inertia term plays an important role in balancing the reconnection electric field near the two edges of the x‐line along the current direction. On the ion drifting side, ions are heated while electron heating is not significant; while on the electron drifting side, electrons are heated while ion heating is weak. In the anti‐parallel case, the out‐of‐plane Hall magnetic field on the ion and electron drifting side of the reconnection region shows reversed polarization, while in the guide field case, the in‐plane Hall electric field shows reversed polarization. These features can be used as identifications for reconnection with a finite x‐line length during observations in the magnetotail, they also provide an estimation of the satellite location in the dawn‐dusk direction of the reconnection region.
Key Points
Three‐dimensional kinetic simulations are used to study reconnection with a finite x‐line length
Electron inertia term plays a crucial role at the two edges of x‐line in the current direction
The features of Hall effect, plasma flow, and plasma heating are different between the dawn and dusk side of the x‐line
van der Waals heterostructures formed by stacking two-dimensional atomic crystals are a unique platform for exploring new phenomena and functionalities. Interlayer excitons, bound states of spatially ...separated electron–hole pairs in van der Waals heterostructures, have demonstrated potential for rich valley physics and optoelectronics applications and been proposed to facilitate high-temperature superfluidity. Here, we demonstrate highly tunable interlayer excitons by an out-of-plane electric field in homobilayers of transition metal dichalcogenides. Continuous tuning of the exciton dipole from negative to positive orientation has been achieved, which is not possible in heterobilayers due to the presence of large built-in interfacial electric fields. A large linear field-induced redshift up to ∼100 meV has been observed in the exciton resonance energy. The Stark effect is accompanied by an enhancement of the exciton recombination lifetime by more than two orders of magnitude to >20 ns. The long recombination lifetime has allowed the creation of an interlayer exciton gas with density as large as 1.2 × 1011 cm–2 by moderate continuous-wave optical pumping. Our results have paved the way for the realization of degenerate exciton gases in atomically thin semiconductors.
This study adopts a stakeholder theory framework to examine determinants of social reporting quality and empirically test the ability of the theory to explain disclosure quality in an emerging ...economy. Using a sample of 246 listed companies and a hand-collected dataset that included 2 years of data based on survey questions reflecting international disclosure trends, we apply an aggregate measure of quality with five facets to a variety of corporate social responsibility areas. The results support the application and demonstrate that measures of stakeholder power, strategic posture, economic resources, firm size, and media visibility are related to social disclosure quality. This paper adds to the scarce evidence on social reporting in Taiwan and provides a useful method for evaluating disclosure quality. It also illustrates the impact of two dominant foreign stakeholder groups on social disclosures in Taiwan: (1) organizational buyers in the global supply chain and (2) listing and social rating agencies in international capital markets.
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