This study examined the relationship between perceived social support and subjective well-being among college students in the context of online learning during the COVID-19 pandemic. 515 college ...students in China that participated in an online questionnaire investigation were selected as the research sample. The results showed that perceived social support was significantly and positively associated with life satisfaction and positive affect and was significantly and negatively related to negative affect among college students learning online during the COVID-19 pandemic. Psychological capital (PsyCap) significantly mediated the relationships between perceived social support and three subjective well-being variables. The present study provides some implications to protect college students’ subjective well-being in the context of online learning during the COVID-19 pandemic.
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EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
Dendritic growth of lithium (Li) is well‐known to originate from deposition on rough and inhomogeneous Li‐metal surfaces, and has long been a central problem in charging lithium metal batteries. ...Herein, a universal strategy is proposed for dendrite suppression by both in situ and ex situ electrochemical polishing of Li metal from the corrosion science perspective. This polishing technique greatly smoothens the surface of the Li and dynamically regenerates a homogeneous solid electrolyte interphase film simultaneously during cell cycling, which suppresses the nucleation sites for dendritic Li and establishes an ideal matrix for even deposition of Li. As a result, the polished Li presents a stable voltage profile and high Li utilization in both the symmetric cells and the full cells coupled with LiNi0.8Co0.1Mn0.1O2 (NCM811) or LiFePO4. The long cycle life of polished Li electrodes clearly demonstrates a uniform dendrite‐free deposition of Li. This strategy shows a new direction to realize a uniform deposition of Li by providing a regenerative homogeneous Li‐surface during repeated cycling.
The highly smooth metallographic surface of Li metal is realized by traditional electrochemical polishing from the corrosion science perspective, which is believed to inhibit dendrite growth intrinsically. The thickness of the solid electrolyte interface of Li metal is tailored by the balanced protective/corrosive effect of the dual‐functional salt couple LiBr‐LiNO3 which facilitates the polishing process.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
We report the development of a highly sensitive ratiometric fluorescent lateral flow immunoassay (RFLFIA) strip for rapid and accurate detection of acute myocardial infarction biomarker, namely ...heart‐type fatty acid binding protein (H‐FABP). The RFLFIA strip works in terms of ratiometric change of fluorescence signal, arising from blending of fluorescence emitted by two composite nanostructures conjugated to capture and probe antibodies and inner filter effect of gold nanoparticles. In conjunction with using custom smartphone‐based analytical device and tonality analysis, quantitative detection of H‐FABP was achieved with a low limit of detection at 0.21 ng mL−1. The RFLFIA strip can generate a visually distinguishable green‐to‐red color change around the threshold concentration of H‐FABP (6.2 ng mL−1), thus allowing the semi‐quantitative diagnosis by the naked eye.
Ratiometric fluorescent lateral flow immunoassay is achieved by inner filter effect‐mediated double‐signal‐reverse change, which not only enables highly sensitive quantitative analysis by combing with the smartphone platform, but also allows the visual readout of H‐FABP concentration by the naked eye. The developed strip can be used for rapid and accurate point‐of‐care testing of acute myocardial infarction.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
The structural defects on graphene grown on a metal substrate via chemical vapor deposition can readily stimulate severe galvanic corrosion phenomena. For any defect passivation method that can be ...technologically promising for superior corrosion‐resistant graphene coatings, efficiency and accuracy are two critical but still challenging requirements. In this work, the authors design a rapid processing method (within just 15 min) that can accurately heal various structural defects of different types and sizes on graphene coating, where the hydrophobic 1H,1H,2H,2H‐perfluorooctanethiol (PFOT) molecules are self‐assembled onto the defect sites. The surface morphologies, atomic bonding states, and defect‐healing mechanism are deeply understood by comprehensive experimental characterizations and first‐principles calculations. Both weak physical PFOT‐pristine graphene bonding and strong covalent PFOT‐defect bonding are two microscopic factors that enhance defect healing efficiency and accuracy. Spatially resolved electronic and electrochemical measurements show that the defect‐healing not only effectively suppresses galvanic corrosion phenomena during both short‐term and long‐term tests, but also well preserves the superior electronic conductivity of pristine graphene. The defect healing strategy proposed here can find its wide potential applications in the fields like electro‐industry, coating, and sensors that require the graphene coatings having both superior corrosion resistance and electronic property.
The detrimental inborn galvanic corrosion effect of chemical vapor deposition‐graphene coating is effectively eliminated by accurately and rapidly healing the defect sites by 1H,1H,2H,2H‐perfluorooctanethiol (PFOT) molecules, which considerably improves the anticorrosion of the metal substrate. Joint experimental characterizations and ab‐initio calculations reveal the essential role of multilateral coupling between defects, graphene/metal interface, and inhibiting PFOT molecules with high defect‐healing efficiency.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SAZU, SBCE, SBMB, UL, UM, UPUK
Topo II and Hsp90 are promising targets. In this study, we first verified the structural similarities between Topo IIα ATPase and Hsp90α N−ATPase. Subsequently, 720 compounds from the Food and Drug ...Administration (FDA) drug library and kinase library were screened using the malachite green phosphate combination with the Topo II-mediated DNA relaxation and MTT assays. Subsequently, the antimalarial drug quinacrine was found to be a potential dual−target inhibitor of Topo II and Hsp90. Mechanistic studies showed that quinacrine could specifically bind to the Topo IIα ATPase domain and inhibit the activity of Topo IIα ATPase without impacting DNA cleavage. Furthermore, our study revealed that quinacrine could bind Hsp90 N−ATPase and inhibit Hsp90 activity. Significantly, quinacrine has broad antiproliferation activity and remains sensitive to the multidrug−resistant cell line MCF−7/ADR and the atypical drug−resistant tumor cell line HL−60/MX2. Our study identified quinacrine as a potential dual−target inhibitor of Topo II and Hsp90, depending on the ATP−binding domain, positioning it as a hit compound for further structural modification.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
Quantum walks are the quantum mechanical analog of classical random walks and an extremely powerful tool in quantum simulations, quantum search algorithms, and even for universal quantum computing. ...In our work, we have designed and fabricated an 8x8 two-dimensional square superconducting qubit array composed of 62 functional qubits. We used this device to demonstrate high fidelity single and two particle quantum walks. Furthermore, with the high programmability of the quantum processor, we implemented a Mach-Zehnder interferometer where the quantum walker coherently traverses in two paths before interfering and exiting. By tuning the disorders on the evolution paths, we observed interference fringes with single and double walkers. Our work is an essential milestone in the field, brings future larger scale quantum applications closer to realization on these noisy intermediate-scale quantum processors.
A series of flexible nanocomposite electrodes were fabricated by facile electro-deposition of cobalt and nickel double hydroxide (DH) nanosheets on porous NiCo2O4 nanowires grown radially on carbon ...fiber paper (CFP) for high capacity, high energy, and power density supercapacitors. Among different stoichiometries of Co x Ni1–x DH nanosheets studied, Co0.67Ni0.33 DHs/NiCo2O4/CFP hybrid nanoarchitecture showed the best cycling stability while maintaining high capacitance of ∼1.64 F/cm2 at 2 mA/cm2. This hybrid composite electrode also exhibited excellent rate capability; the areal capacitance decreased less than 33% as the current density was increased from 2 to 90 mA/cm2, offering excellent specific energy density (∼33 Wh/kg) and power density (∼41.25 kW/kg) at high cycling rates (up to150 mA/cm2).
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IJS, KILJ, NUK, PNG, UL, UM
A hierarchical first-principles study has been performed to reveal the roles of mass, structure, and atomic bond strength in phonon spectra, phonon anharmonicity, thermal expansion, and ...thermomechanics of single-layer Mo and W dichalcogenides (MX2, X = S, Se, and Te). The strength of the M–X bond is determined by the competition between ionicity and covalency and increases (decreases) with increasing the cation (anion) nucleon number. The total mass and cation–anion mass ratio isotopically influence phonon frequencies. The twofold lattice dimensionality renders the bending ZA mode with parabolic dispersion and negative Grüneisen constant (γ). While nonorthogonal bonds lead to interdirection vibrational hybridizations, which increases γZA but decreases γTA and γLA. The minima of γTA and γLA decrease with decreasing bond strength and become negative in MTe2. MX2 always has a negative thermal expansion at low temperatures (T < 50 K) due to the advanced excitation of those low negative-γ ZA modes. At higher temperatures, the excitation of other positive-γ modes results in positive thermal expansion. Additionally, thermal expansion is determined jointly by lattice stiffness, phonon excitation, and phonon anharmonicity. The contributions of these involved factors are quantitatively disentangled here, and their relationships with mass, structure, and bond strength are revealed. The softening of the bulk modulus of MX2 under heating is mainly caused by thermal expansion, which is partially canceled by the stiffening effect from phonon excitation. Both bulk modulus and its thermal softening rate decrease with anion nucleon number, due to the decrease in bond strength and bond-strength anharmonicity, respectively.
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IJS, KILJ, NUK, PNG, UL, UM
Abstract
Molybdenum disulfide has broad applications in catalysis, optoelectronics, and solid lubrication, where lanthanide (Ln) doping can be used to tune its physicochemical properties. The ...reduction of oxygen is an electrochemical process important in determining fuel cell efficiency, or a possible environmental-degradation mechanism for nanodevices and coatings consisting of Ln-doped MoS
2
. Here, by combining density-functional theory calculations and current-potential polarization curve simulations, we show that the dopant-induced high oxygen reduction activity at Ln-MoS
2
/water interfaces scales as a biperiodic function of Ln type. A defect-state pairing mechanism, which selectively stabilizes the hydroxyl and hydroperoxyl adsorbates on Ln-MoS
2
, is proposed for the activity enhancement, and the biperiodic chemical trend in activity is found originating from the similar trends in intraatomic 4
f
–5
d
6
s
orbital hybridization and interatomic Ln–S bonding. A generic orbital-chemistry mechanism is described for explaining the simultaneous biperiodic trends observed in many electronic, thermodynamic, and kinetic properties.
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To ensure a long-term quantum computational advantage, the quantum hardware should be upgraded to withstand the competition of continuously improved classical algorithms and ...hardwares. Here, we demonstrate a superconducting quantum computing systems Zuchongzhi 2.1, which has 66 qubits in a two-dimensional array in a tunable coupler architecture. The readout fidelity of Zuchongzhi 2.1 is considerably improved to an average of 97.74%. The more powerful quantum processor enables us to achieve larger-scale random quantum circuit sampling, with a system scale of up to 60 qubits and 24 cycles, and fidelity of FXEB=(3.66±0.345)×10-4. The achieved sampling task is about 6 orders of magnitude more difficult than that of Sycamore Nature 574, 505 (2019) in the classic simulation, and 3 orders of magnitude more difficult than the sampling task on Zuchongzhi 2.0 arXiv:2106.14734 (2021). The time consumption of classically simulating random circuit sampling experiment using state-of-the-art classical algorithm and supercomputer is extended to tens of thousands of years (about 4.8×104 years), while Zuchongzhi 2.1 only takes about 4.2 h, thereby significantly enhancing the quantum computational advantage.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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