310 research outputs found

    Exploring the communication effects of signals and messages in the COVID-19 health crisis

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    The ongoing coronavirus disease 2019 (COVID-19) pandemic presents an unprecedented global public health crisis. In this scenario, crisis communication on social media that largely influences people’s emotions, attitudes and interaction behaviours towards a large-scale public health crisis plays a critical role in persuading the public’s behaviour adjustment and coping with the risk. The effects of crisis communication strategies and signals embedded in social media topics and messages warrant further investigation. This study explored and tested the communication effects of crisis messages and topics from the initial event stage to the normalized control stage of the COVID-19 crisis using texts scraped from a Chinese social media website, namely Weibo. Natural language processing (NLP) techniques, i.e., sentiment and emotion analysis, positivist text coding, and ordinary least squares (OLS) were used in data analysis. This study contributes to the crisis management literature and theories by identifying and testing a number of factors and signals in crisis communication on social media that influence receivers’ reactions and behaviours. In doing so, this study provides suggestions for practitioners and policymakers on effective communication of the crisis situation and prevention behaviours to the public

    Current Status and Prospects Towards the Road of Universal Health Coverage (UHC) in China: a Systematic Review

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    Background: Over the past decade, China has successfully extended its basic healthcare safety net to more than 95% of the population. The Chinese government aims to provide universal health coverage for all citizens by 2030. However, China still suffers from an inadequate tiered medical care system, lack of information sharing on hospital visits, and medical staff with low salaries and excessive overtime. This paper will further discuss China's current status and prospects in six building blocks of the WHO health system framework. Methods: We used various popular search engines, such as PubMed, Google, Google Scholar, etc., to identify studies on achieving universal health in China. The purpose of the search was to understand the state of the existing health system in China, especially in mobile health (mhealth), mental health, and medical personnel protection. Findings: We found nine articles related to health service delivery, three articles related to the medical workforce, four articles related to health information systems, three articles related to medical products, vaccines, and technologies, five articles related to health financing, and five articles related to health system management. Discussion: The findings based on the six health system building blocks are summarized in conjunction with other literature

    Experimental Study of Tendon Failure Analysis for a TLP Floating Offshore Wind Turbine

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    This paper describes an experimental study conducted on a multi-column tension leg platform (TLP) floating offshore wind turbine (FOWT). A prototype model of the TLP FOWT supporting the NREL 5-MW wind turbine with a scale ratio of 1:50 is tested under various wind and wave conditions at the State Key Laboratory of Coastal and Offshore Engineering at Dalian University of Technology, China. This work has particularly focused on the tendon failure and its impact on the dynamic response of the FOWT. Free decay tests, regular wave tests, wind-wave combined tests and tendon failure tests are conducted using different environmental parameters.The results suggest that natural periods, dynamic responses of the platform, and forces in the tendons satisfy the design requirements. The analysis indicates that the impact of tendon failure on the platform surge, heave and pitch responses are found to be insignificant. When one of the tendons is broken, the adjacent tendons experience a significant increase in tensile force; and, the maximum tensile force in the remaining tendon is found to increase by about 130%. The overstepping of the minimum breaking load as recommended by the design standard DNV GL is not reached, and this indicates that the safety of the system is ensured even during the harshest failure condition

    (<b><i>α, β</i></b>) - Lock Resolution Method of Linguistic Truth-Valued Intuitionistic Fuzzy First-order Logic

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    Automated reasoning is an important research direction in artificial intelligence, and resolution method is an efficient logical reasoning tool, it deserves to be studied. This paper establishes linguistic truth-valued intuitionistic fuzzy first-order logic (LTV-IFFL) system. To improve the resolution efficiency, the (αβ)-lock resolution method is introduced into LTV-IFFL system and requires that the resolution literal is the literal with the smallest lock number. Its soundness and completeness are proved. Finally, we give the (αβ) -locked resolution of the LTV-IFFL and apply it to the example.</p

    Intrinsic Defects in LiMn2_{2}O4_{4}: First-Principles Calculations

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    Spinel LiMn2_{2}O4_{4} has attracted wide attention due to its advantages of a high-voltage plateau, good capacity, environmental friendliness, and low cost. Due to different experimental synthesis methods and conditions, there are many intrinsic point defects in LiMn2_{2}O4_{4}. By means of first-principles calculations based on a reasonable magnetic configuration, we studied the formation energies, local structures, and charge compensation mechanism of intrinsic point defects in LiMn2_{2}O4_{4}. The formation energies of defects under the assumed O-rich equilibrium conditions were examined. It was found that O, Li, and Mn vacancies, Mn and Li antisites, and Li interstitial could appear in the lattice at some equilibrium conditions, but Mn interstitial is hard to form. The charge was compensated mainly by adjusting the oxidation state of Mn around the defect, except for the defects at the 8a Wyckoff site. The binding energies between point defects were calculated to shed light on the clustering of point defects. Furthermore, the diffusion of Li ions around the defects was discussed. Cation antisites led to a decrease of the Li diffusion barrier but O vacancy caused an increase of the barrier. This study provides theoretical support for understanding point defects in spinel LiMn2_{2}O4_{4}

    Amylose-Derived Macrohollow Core and Microporous Shell Carbon Spheres as Sulfur Host for Superior Lithium–Sulfur Battery Cathodes

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    Porous carbon can be tailored to great effect for electrochemical energy storage. In this study, we propose a novel structured spherical carbon with a macrohollow core and a microporous shell derived from a sustainable biomass, amylose, by a multistep pyrolysis route without chemical etching. This hierarchically porous carbon shows a particle distribution of 2–10 μm and a surface area of 672 m2 g–1. The structure is an effective host of sulfur for lithium–sulfur battery cathodes, which reduces the dissolution of polysulfides in the electrolyte and offers high electrical conductivity during discharge/charge cycling. The hierarchically porous carbon can hold 48 wt % sulfur in its porous structure. The S@C hybrid shows an initial capacity of 1490 mAh g–1 and retains a capacity of 798 mAh g–1 after 200 cycles at a discharge/charge rate of 0.1 C. A capacity of 487 mAh g–1 is obtained at a rate of 3 C. Both a one-step pyrolysis and a chemical-reagent-assisted pyrolysis are also assessed to obtain porous carbon from amylose, but the obtained carbon shows structures inferior for sulfur cathodes. The multistep pyrolysis and the resulting hierarchically porous carbon offer an effective approach to the engineering of biomass for energy storage. The micrometer-sized spherical S@C hybrid with different sizes is also favorable for high-tap density and hence the volumetric density of the batteries, opening up a wide scope for practical applications
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