502 research outputs found

    Service Quality Management of Scenic Spot Based on Tourists\u27 Experience--Taking the Three Gorges Dam 5A Scenic Area for Example

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    Based on the perspective of tourists, the paper takes the empirical analysis of service quality of the three gorges dam scenic spot, tries to put forward some methods to improve service quality, and provide the reference for the tourism sustainable optimization development of the three gorges dam

    Time of day is associated with paradoxical reductions in global signal fluctuation and functional connectivity.

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    The brain exhibits substantial diurnal variation in physiology and function, but neuroscience studies rarely report or consider the effects of time of day. Here, we examined variation in resting-state functional MRI (fMRI) in around 900 individuals scanned between 8 AM and 10 PM on two different days. Multiple studies across animals and humans have demonstrated that the brain's global signal (GS) amplitude (henceforth referred to as "fluctuation") increases with decreased arousal. Thus, in accord with known circadian variation in arousal, we hypothesised that GS fluctuation would be lowest in the morning, increase in the midafternoon, and dip in the early evening. Instead, we observed a cumulative decrease in GS fluctuation as the day progressed. Although respiratory variation also decreased with time of day, control analyses suggested that this did not account for the reduction in GS fluctuation. Finally, time of day was associated with marked decreases in resting-state functional connectivity across the whole brain. The magnitude of decrease was significantly stronger than associations between functional connectivity and behaviour (e.g., fluid intelligence). These findings reveal time of day effects on global brain activity that are not easily explained by expected arousal state or physiological artefacts. We conclude by discussing potential mechanisms for the observed diurnal variation in resting brain activity and the importance of accounting for time of day in future studies

    A plasmonic nanosensor with inverse sensitivity for circulating cell-free DNA quantification

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    A plasmonic nanosensor (using gold nanorods) with inverse sensitivity is presented for circulating cell-free DNA quantification. The inverse sensitivity (i.e. the lower the analyte concentration, the higher the response intensity) is achieved by the unusual DNA concentration-dependent gold nanorod aggregation. This assay method can adjust the dynamic range by controlling the concentration of nanoparticles in solution. Graphical abstract: A plasmonic nanosensor with inverse sensitivity for circulating cell-free DNA quantificatio

    Probing new physics with polarized τ\tau and Λc\Lambda_c in quasielastic ντ ⁣+ ⁣n ⁣ ⁣τ ⁣+ ⁣Λc\nu_{\tau}\!+\!n\!\to\! \tau^-\!+\!\Lambda_c scattering process

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    The absence of semitauonic decays of charmed hadrons makes the decay processes mediated by the quark-level cdτ+ντc\to d \tau^+ \nu_{\tau} transition inadequate for probing a generic new physics (NP) with all kinds of Dirac structures. To fill in this gap, we consider in this paper the quasielastic neutrino scattering process ντ+nτ+Λc\nu_{\tau}+n\to \tau^-+\Lambda_c, and propose searching for NP through the polarizations of the τ\tau lepton and the Λc\Lambda_c baryon. In the framework of a general low-energy effective Lagrangian, we perform a comprehensive analysis of the (differential) cross sections and polarization vectors of the process both within the Standard Model and in various NP scenarios, and scrutinize possible NP signals. We also explore the influence on our findings due to the uncertainties and the different parametrizations of the ΛcN\Lambda_c \to N transition form factors, and show that they have become one of the major challenges to further constrain possible NP through the quasielastic scattering process.Comment: 31 pages, 17 figures, and 3 tables. Comments are welcom

    Unraveling the effect of salt chemistry on long-durability high-phosphorus-concentration anode for potassium ion batteries

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    Phosphorus-based anode materials are of considerable interest for grid-scale energy storage systems due to their high theoretical capacity. Nevertheless, the low electrical conductivity of P, large volume changes during cycling, and highly-reactive phosphide surface are hindering their potential applications. Herein, outstanding long-term cycling stability with high retained potassium storage capacity (213.7 mA h g−1over 2000 cycles) was achieved via the introduction of an alternative potassium bis(fluorosulfonyl)imide (KFSI) salt and by using a layered compound (GeP5) with a high phosphorus concentration as anode material. Fourier transform infrared spectroscopic mapping results suggest that KFSI salt helps to form an uniform solid electrolyte interphase (SEI) layer and reduces the side reactions at the electrode/electrolyte interface, thus enhancing the cycling performance. In-operando synchrotron X-ray diffraction analysis has revealed the synergistic reaction mechanisms of the K-P and K-Ge reactions. These findings indicate the enormous potential of phosphorus-based anodes for high-performance potassium ion batteries and can attract broad interest for regulating the SEI layer formation through manipulating the salt chemistry
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