High theoretical capacity and high energy density make lithium sulfur (Li‐S) batteries a competitive candidate for next‐generation energy storage systems. However, achieving the practical application ...of Li‐S batteries is still a huge challenge due to some inevitable obstacles. Poor conductivity of active sulfur, large volume expansion of cathode, and severe shuttle effect of lithium polysulfides (LiPSs) greatly limit the capacity of cells and lead to unsatisfied cycle performance. Therefore, various sulfur host materials have been proposed and investigated, which should possess good conductivity, porous structure, and strong immobilization capability for LiPSs. Unfortunately, it is incompetent to cover all the advantages mentioned above for pristine materials. Heteroatom doping fundamentally manipulates the electronic structure and polarity of materials, leading to some unprecedented properties, and subsequent enhancement in electrochemical performance. This review systematically summarizes the recent progress of heteroatom (metal single atom and non‐metal atom) doping in various materials including carbon materials, graphitic carbon nitride (g‐C3N4), and metal compounds as the ideal sulfur host. Furthermore, the relationship between the unique features of sulfur host materials originated from heteroatom doping and enhanced performance of cells is comprehensively discussed.
Heteroatom doping is an effective strategy to manipulate the electronic structure and polarity of sulfur host materials, resulting in the enhancement of features and performance. This review summarizes the doping of non‐metal heteroatoms and metal single atoms in carbon materials and metal compounds in Li‐S batteries, and the mechanism of enhanced performance originating from heteroatom doping is overviewed.
The objective of this paper is to understand transport behavior in uncertain time-varying flow fields by redefining the finite-time Lyapunov exponent (FTLE) and Lagrangian coherent structure (LCS) as ...stochastic counterparts of their traditional deterministic definitions. Three new concepts are introduced: the distribution of the FTLE (D-FTLE), the FTLE of distributions (FTLE-D), and uncertain LCS (U-LCS). The D-FTLE is the probability density function of FTLE values for every spatiotemporal location, which can be visualized with different statistical measurements. The FTLE-D extends the deterministic FTLE by measuring the divergence of particle distributions. It gives a statistical overview of how transport behaviors vary in neighborhood locations. The U-LCS, the probabilities of finding LCSs over the domain, can be extracted with stochastic ridge finding and density estimation algorithms. We show that our approach produces better results than existing variance-based methods do. Our experiments also show that the combination of D-FTLE, FTLE-D, and U-LCS can help users understand transport behaviors and find separatrices in ensemble simulations of atmospheric processes.
The past decade has been especially creative for spintronics since the (re)discovery of various two dimensional (2D) materials. Due to the unusual physical characteristics, 2D materials have provided ...new platforms to probe the spin interaction with other degrees of freedom for electrons, as well as to be used for novel spintronics applications. This review briefly presents the most important recent and ongoing research for spintronics in 2D materials.
We previously found that B and AGL6 proteins form L (OAP3-2/OAGL6-2/OPI) and SP (OAP3-1/OAGL6-1/OPI) complexes to determine lip/sepal/petal identities in orchids. Here, we show that the functional L' ...(OAP3-1/OAGL6-2/OPI) and SP' (OAP3-2/OAGL6-1/OPI) complexes likely exist and AP3/PI/AGL6 genes have acquired additional functions during evolution. We demonstrate that the presumed L' complex changes the structure of the lower lateral sepals and helps the lips fit properly in the center of the flower. In addition, we find that OAP3-1/OAGL6-1/OPI in SP along with presumed SP' complexes regulate anthocyanin accumulation and pigmentation, whereas presumed L' along with OAP3-2/OAGL6-2/OPI in L complexes promotes red spot formation in the perianth. Furthermore, the B functional proteins OAP3-1/OPI and OAGL6-1 in the SP complex could function separately to suppress sepal/petal senescence and promote pedicel abscission, respectively. These findings expand the current knowledge behind the multifunctional evolution of the B and AGL6 genes in plants.
We consider the time-reversal odd dynamics of the bilayer graphene at low energies in the quantum Hall regime. A generating functional for the effective action that captures the electromagnetic ...response to all orders in momentum and frequency is presented and evaluated to the third order in the space-time gradient O(∂^{3}). In addition, we calculate the Hall viscosity and derive an explicit relationship with the q^{2} coefficient of the Hall conductivity. It is reminiscent of the Hoyos-Son relation in Galilean invariant systems, which can be recovered in the limit of large filling factor N.
In this study, hydroxyl-modified/Na-intercalated g-C3N4 was used as an effective material for the removal of gaseous formaldehyde (HCHO) through adsorption and photocatalytic oxidation. In a simple ...reflux reaction using different NaOH concentrations, the surface-grafted hydroxyl (‒OH) groups of g-C3N4 formed internal hydrogen bonds with gaseous HCHO, while the Na atoms intercalated into the layered structure of g-C3N4 to create an electron transfer path (layer‒Na‒layer) to improve charge separation for photocatalytic oxidation. The hydroxylation as well as Na intercalation of g-C3N4 significantly increased its HCHO removal efficiency compared with that of bare g-C3N4. The HCHO removal capacity of the modified g-C3N4 reached approximately 0.12 ppm g−1 min−1, which was twice that of bare g-C3N4 (<0.06 ppm g−1 min−1). Moreover, the modified g-C3N4 was reused at least thrice without any decline in activity. This work provides a facile, simple, and fast approach to the modification of g-C3N4 via hydroxylation and Na intercalation to enhance HCHO adsorption as well as electron transfer, rendering it a promising material for indoor HCHO removal.
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•Hydroxyl-modified and Na-intercalated g-C3N4 was prepared via treatment with NaOH.•Hydroxylation of g-C3N4 significantly improved HCHO adsorption.•Na intercalation in g-C3N4 created an electron transfer path for charge migration.•Hydroxyl-modified and Na-intercalated g-C3N4 exhibited high HCHO removal performance.
With the fast‐growing demand for green and safe energy sources, rechargeable ion batteries have gradually occupied the major current market of energy storage devices due to their advantages of high ...capacities, long cycling life, superior rate ability, and so on. Metallic Sn‐based anodes are perceived as one of the most promising alternatives to the conventional graphite anode and have attracted great attention due to the high theoretical capacities of Sn in both lithium‐ion batteries (LIBs) (994 mA h g−1) and sodium‐ion batteries (847 mA h g−1). Though Sony has used Sn–Co–C nanocomposites as its commercial LIB anodes, to develop even better batteries using metallic Sn‐based anodes there are still two main obstacles that must be overcome: poor cycling stability and low coulombic efficiency. In this review, the latest and most outstanding developments in metallic Sn‐based anodes for LIBs and SIBs are summarized. And it covers the modification strategies including size control, alloying, and structure design to effectually improve the electrochemical properties. The superiorities and limitations are analyzed and discussed, aiming to provide an in‐depth understanding of the theoretical works and practical developments of metallic Sn‐based anode materials.
To overcome the main obstacles of poor cycling stability and low coulombic efficiency faced by metallic Sn‐based anodes, a lot of modification methods have been developed, including size control, alloying, and structure design. In this review, the state‐of‐the‐art works of metallic Sn‐based anodes are summarized and classified, and the superiorities and limitations are analyzed and discussed.
•The study investigates on the factors influencing users' IU to adopt SCC.•MPC, MU and MPT have significant impact on IU.•MEU, MPSR and MPFR are non-significant with IU.•MPC and MPFR have significant ...influence on MU.•MPC has significant influence on MEU while MPFR is non-significant with MEU.
Smartphone credit card (SCC) is an emerging payment method using NFC-enabled smartphones. The proximity payment allows consumers to pay their products and services by waving their smartphones with a NFC reader. While there are advantageous adopting SCC, the adoption rate has not been encouraging. Interestingly, existing research work on past information technology and system models have so far focused primarily on organizational context and adopted specifically for work. Furthermore, past antecedents were mainly constructed using electronic commerce literatures which do not reflect the actual mobile environment. In contrast SCC is mainly adopted voluntarily by mobile users and for personal purposes. Thus this leads to the difficulty in drawing meaningful conclusion. The study addresses these limitations by proposing a new mobile technology acceptance model (MTAM) which consists of mobile usefulness (MU) and mobile ease of use (MEU) to determine SCC adoption. In anticipating on the complexity which exists in the mobile environment, additional mobile constructs namely mobile perceived security risk (MPSR), mobile perceived trust (MPT), mobile perceived compatibility (MPC) and mobile perceived financial resources (MPFR) were incorporated into the parsimonious MTAM. The integrated model was applied to 459 mobile users through a questionnaire approach and tested using partial least square-structural equation modelling-artificial neural network (PLS-SEM-ANN) has provided a new impact and a possible new research methodology paradigm as it is able to capture both linear and non-linear relationships. While the model confirms the role of MU in MTAM, MEU needs for more attention in practice. The results from the extended model showed that only three of the proposed hypotheses were non-significant in this study and thus warrant further investigation. The study contributes to academia by proposing new mobile constructs that brings together MTAM to assess the likelihood of mobile users to adopt SCC. The study also offers several important managerial implications which can be generalized to the mobile studies of other transportation, hotel, banking, and tourism industries.
SUMMARY
Ethylene‐responsive factors (ERFs) have diverse functions in the regulation of various plant developmental processes. Here, we demonstrate the dual role of an Arabidopsis ERF gene, AtERF19, ...in regulating reproductive meristem activity and flower organ size through the regulation of genes involved in CLAVATA–WUSCHEL (CLV–WUS) and auxin signaling, respectively. We found that AtERF19 stimulated the formation of flower primordia and controlled the number of flowers produced by activating WUS and was negatively regulated by CLV3. 35S::AtERF19 expression resulted in significantly more flowers, whereas 35S::AtERF19 + SRDX dominant‐negative mutants produced fewer flowers. In addition, AtERF19 also functioned to control flower organ size by promoting the division/expansion of the cells through activating Small Auxin Up RNA Gene 32 (SAUR32), which positively regulated MYB21/24 in the auxin signaling pathway. 35S::AtERF19 and 35S::SAUR32 resulted in similarly larger flowers, whereas 35S::AtERF19 + SRDX and 35S::SAUR32‐RNAi mutants produced smaller flowers than the wild type. The functions of AtERF19 were confirmed by the production of similarly more and larger flowers in 35S::AtERF19 transgenic tobacco (Nicotiana benthamiana) and in transgenic Arabidopsis which ectopically expressed the orchid gene (Nicotiana benthamiana) PaERF19 than in wild‐type plants. The finding that AtERF19 regulates genes involved in both CLV–WUS and auxin signaling during flower development significantly expands the current knowledge of the multifunctional evolution of ERF genes in plants. The results presented in this work indicate a dual role for the transcription factor AtERF19 in controlling the number of flowers produced and flower organ size through the regulation of genes involved in CLV–WUS and auxin signaling, respectively. Our findings expand the knowledge of the roles of ERF genes in the regulation of reproductive development.
Significance Statement
The results presented in this work indicate a dual role for the transcription factor AtERF19 in controlling the number of flowers produced and flower organ size through the regulation of genes involved in CLAVATA–WUSCHEL and auxin signaling, respectively. Our findings expand the knowledge of the roles of ERF genes in the regulation of reproductive development.
The MXene‐based heterostructures have recently attracted great interest as anode materials for sodium‐ion batteries (SIBs). Nonetheless, the complicated and harsh preparation process impedes their ...further commercialization. Herein, a novel, safe, low‐destructive, and universal strategy for rationally fabricating Ti3C2Tx MXene/transition metal sulfides (MSy) heterostructures is presented via Lewis acidic molten salts etching and subsequent in situ sulfurization treatment. Benefiting from the interfacial electronic coupling between highly conductive Ti3C2Tx MXene (Tx = O and Cl) and MSy (M = Fe, Co and Ni), the heterostructures possess remarkably improved electronic conductivity, promoted Na+ migration kinetics, and robust architectures. As a proof‐of‐concept demonstration, the Ti3C2Tx/FeS2 heterostructure demonstrates outstanding rate performance (456.6 mAh g−1 at 10 A g−1) and long‐term cyclic stability (474.9 mAh g−1 after 600 cycles at 5 A g−1) when serving as SIB anodes. Impressively, a sodium‐ion full battery with Ti3C2Tx/FeS2 anode delivers an excellent reversible capacity of 431.6 mAh g−1 after 1000 cycles at 3 A g−1. Moreover, the dual sodium storage behavior of Ti3C2Tx/FeS2 heterostructure and underlying mechanism toward exceptional electrochemical performance are revealed by comprehensive characterizations and theoretical calculations. Based on the full utilization of molten salt etching products, the present work offers new insight into the fabrication of MXene‐based heterostructures.
A series of Ti3C2Tx MXene/MSy heterostructures (Tx = O and Cl, M = Fe, Co, and Ni) are fabricated by directly vulcanizing Ti3C2Tx/metal hybrids obtained by etching a Ti3AlC2 MAX precursor with various Lewis acidic molten salts, which is a simple, safe, low‐destructive, and general strategy. The heterostructures present superior electrochemical performance as anode materials for sodium‐ion batteries derived from the interfacial electronic coupling effect.
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