An Analysis of Effects of Boredom on Revisit Intention – A Case in Japanese Popular Tourism Destinations

This study focuses on the effects of visitors’ boredom of a destination on their intention to revisit it, using two Japanese popular tourism destinations as the cases. Relationships between three factors, which are satisfaction, boredom and revisit intention, were examined. In addition to the subjective index of visitors’ boredom based on ratings on a scale, the rate of remaining facilities (RoRF), which was the objective index of visitors’ boredom, is also employed. A questionnaire survey was conducted to obtain data related to the five factors. We conclude that subjective index of visitors’ boredom may not be effective for understanding of their revisit intention, while their revisit intention can arguably be relevant to the RoRF

Cation-Disordered Li3VO4: Reversible Li Insertion/Deinsertion Mechanism for Quasi Li-Rich Layered Li1+x[V1/2Li1/2]O2 (x = 0–1)

The reversible lithiation/delithiation mechanism of the cation-disordered Li3VO4 material was elucidated, including the understanding of structural and electrochemical signature changes during cycling. The initial exchange of two Li induces a progressive and irreversible migration of Li and V ions from tetrahedral to octahedral sites, confirmed by the combination of in situ/operando X-ray diffraction and X-ray absorption fine structure analyses. The resulting cation-disordered Li3VO4 can smoothly and reversibly accommodate two Li and shows a Li+ diffusion coefficient larger by 2 orders of magnitude than the one of pristine Li3VO4, leading to improved electrochemical performance. This cation-disordered Li3VO4 negative electrode offers new opportunities for designing high-energy and high-power supercapacitors. Furthermore, it opens new paths for preparing disordered compounds with the general hexagonal close-packing structure, including most polyanionic compounds, whose electrochemical performance can be easily improved by simple cation mixing

Ultrafast charge–discharge characteristics of a nanosized core–shell structured LiFePO4 material for hybrid supercapacitor applications

Highly dispersed crystalline/amorphous LiFePO4 (LFP) nanoparticles encapsulated within hollow-structured graphitic carbon were synthesized using an in situ ultracentrifugation process. Ultracentrifugation triggered an in situ sol–gel reaction that led to the formation of core–shell LFP simultaneously hybridized with fractured graphitic carbon. The structure has double cores that contain a crystalline LFP (core 1) covered by an amorphous LFP containing Fe3+ defects (core 2), which are encapsulated by graphitic carbon (shell). These core–shell LFP nanocomposites show improved Li+ diffusivity thanks to the presence of an amorphous LFP phase. This material enables ultrafast discharge rates (60 mA h g-1 at 100C and 36 mA h g-1 at 300C) as well as ultrafast charge rates (60 mA h g-1 at 100C and 36 mA h g-1 at 300C). The synthesized core–shell nanocomposites overcome the inherent one-dimensional diffusion limitation in LFP and yet deliver/store high electrochemical capacity in both ways symmetrically up to 480C. Such a high rate symmetric capacity for both charge and discharge has never been reported so far for LFP cathode materials. This offers new opportunities for designing high-energy and high-power hybrid supercapacitors

Stabilizing the Structure of LiCoPO4 Nanocrystals via Addition of Fe3+: Formation of Fe3+ Surface Layer, Creation of Diffusion-Enhancing Vacancies, and Enabling High-Voltage Battery Operation

Factors affecting the cyclability of the Fe-substituted LiCoPO4 (LiCo0.8Fe0.2PO4, LCFP) material were elucidated, including both the structural and electrode/electrolyte stability. Electrochemical characterization of the synthesized LCFP nanoparticles lends clear evidence for improved electrochemical stability of LCP, as well as enhanced rate capability, with Fe3+ substitution. Surface analysis using X-ray photoelectron spectroscopy (XPS) and electron energy loss spectroscopy (EELS) suggest that Fe enrichment on the surface of LCFP occurs through the oxidation of Fe2+ into Fe3+ in the synthesis process. The Fe3+-rich phase on the LCP surface enhances the stability of the delithiated phase, preventing oxidative reactions with electrolytes during high-voltage operation. This surface protection persists as long as the electrochemical reduction of Fe3+ is avoided by ensuring that the full range of operating voltages lie above the Fe3+/Fe2+ redox potential. Our findings may offer new approaches to stabilize the structure of LCP and other high-voltage positive electrodes for use in 5 V-class Li-ion batteries

Noncrystalline Nanocomposites as a Remedy for the Low Diffusivity of Multivalent Ions in Battery Cathodes

Rechargeable batteries using multivalent metals are among the most promising next-generation battery systems due to their high capacity, high safety, and low cost compared with lithium-ion batteries. However, strong cation−anion interaction degrades diffusion in solid cathodes, an effect that must be mitigated to yield practical multivalent metal batteries. We show that a highly defective iron phosphate−carbon composite prepared by ultracentrifugation serves as a reversible insertion/deinsertion for magnesium ions with, and operates beyond, a 2-V cell voltage at room temperature. A composite of noncrystalline particles that embeds the surrounding carbon structure enhances the magnesium-ion diffusion in the solid phase with stability for cycle life. X-ray absorption spectroscopy, transmission electron microscopy with energy-dispersive X-ray spectroscopy, and high-energy X-ray scattering measurements demonstrate magnesium-ion insertion and extraction in the defective iron phosphate without conversion reactions. This work suggests promising applications for highly defective structures as intercalation hosts for multivalent ions

Extreme-value analysis of intracellular cargo transport by motor proteins

Abstract The mechanisms underlying the chemo-mechanical coupling of motor proteins is usually described by a set of force-velocity relations that reflect the different mechanisms responsible for the walking behavior of such proteins on microtubules. However, the convexity of such relations remains controversial depending on the species, and in vivo experiments are inaccessible due to the complexity of intracellular environments. As alternative tool to investigate such mechanism, Extreme-value analysis (EVA) can offer insight on the deviations in the data from the median of the probability distributions. Here, we rely on EVA to investigate the motility functions of nanoscale motor proteins in neurons of the living worm Caenorhabditis elegans (C. elegans), namely the motion of kinesin and dynein along microtubules. While the essential difference between the two motors cannot be inferred from the mean velocities, such becomes evident in the EVA plots. Our findings extend the possibility and applicability of EVA for analysing motility data of nanoscale proteins in vivo