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BackgroundSo far, there have been no published population studies on the relationship between a COVID-19 infection and public risk perception, information source, knowledge, attitude, and behaviors during the COVID-19 outbreak in China. ObjectiveThis study aims to understand the relationships between COVID-19 infection; four personal nonpharmaceutical interventions (NPIs; handwashing, proper coughing habits, social distancing, and mask wearing); and public risk perception, knowledge, attitude, and other social demographic variables. MethodsAn online survey of 8158 Chinese adults between February 22 and March 5, 2020, was conducted. Bivariate associations between categorical variables were examined using Fisher exact test. We also explored the determinants of four NPIs as well as their association with COVID-19 infection using logistic regression. ResultsOf 8158 adults included, 57 (0.73%) were infected with COVID-19. The overwhelming majority of respondents showed a positive attitude (n=8094, 99.2%), positive risk perception (n=8146, 99.9%), and high knowledge levels that were among the strongest predictors of the four adopted NPIs (handwashing: n=7895, 96.8%; proper coughing: 5997/6444, 93.1%; social distancing: n=7104/8158, 87.1%; and mask wearing: 5011/5120, 97.9%). There was an increased risk of COVID-19 infection for those who did not wash their hands (2.28% vs 0.65%; risk ratio [RR] 3.53, 95% CI 1.53-8.15; P=.009), did not practice proper coughing (1.79% vs 0.73%; RR 2.44, 95% CI 1.15-5.15; P=.03), did not practice social distancing (1.52% vs 0.58%; RR 2.63, 95% CI 1.48-4.67; P=.002), and did not wear a mask (7.41% vs 0.6%; RR 12.38, 95% CI 5.81-26.36; P

Inconel 706 (IN706) alloy is commonly used in aircraft engines and power plant components that must meet very high performance requirements. The stabilization treatment has a significant effect on the precipitation and evolution of the reinforcing phases of the alloy, favoring the creep properties and adversely affecting the room-temperature tensile properties. However, the mechanism of the effect of the stabilization treatment on the mechanical properties of the alloys remains unclear. In this study, the effect of stabilization treatment time on the microstructure and tensile properties of IN706 alloy was investigated. The results showed that as the stabilization time gradually increased, the tensile strength remained basically unchanged (about 1250 MPa), the yield strength decreased from 1031 MPa to 985 MPa, and the plasticity decreased from 28.2% to 20.2%. The stabilization treatment induces the precipitation of granular, rod-shaped, and needle-like η phases at grain boundaries, accompanied by the appearance of a precipitate free zone (PFZ). Since the η phase is enriched with Ti and Nb, its precipitation along the grain boundary results in the depletion of Ti and Nb in the surrounding regions, thereby constraining the precipitation of the γ′ and γ″ phases, resulting in the appearance of PFZ. With increasing stabilization time, the size increase and volume fraction decrease in γ′-γ″ co-precipitates due to the precipitation of η-phase precipitates, leading to a decrease in their yield strength. Combined with in situ tensile tests, it was found that the decrease in the elongation of the stabilization treatment samples was due to the presence of η phase at the grain boundaries, which induced stress concentration and cracking at the grain boundaries. The results show that the mechanical properties of the material were gradually enhanced as the stabilization time decreased. This means it can help to choose the suitable process for IN706 alloy in different service conditions. [ABSTRACT FROM AUTHOR]

In this article, we subjected the Ti60 alloy to solid-solution treatment at 1020 °C and aging treatment at 600 °C, respectively, achieving a bimodal microstructure. The microstructures obtained after aging treatment showed no significant difference in the primary α-phase content, size, and width of the lamellar α phase. This suggests that the final microstructure morphology is primarily determined by the solid-solution temperature, with the aging process exerting less pronounced effects on microstructural alterations. Furthermore, we investigated the effect of solid-solution and aging treatment on the crystallographic orientation evolution of the secondary α phase (αs) in the near-α titanium alloy Ti60. The αs phase displays a random orientation in solid-solution treatment sample, while it demonstrated a preferential {0 1 −1 0} orientation after aging treatment. This interesting phenomenon is attributed to the enhanced variant selection resulting from the dissolution of variant near 60° and 90° during aging. Furthermore, the αs with {0 1 −1 0} orientation nucleated at the grain boundary and coalesced into larger αs lath with increasing aging time, further contributing to the αs {0 1 −1 0} texture. [ABSTRACT FROM AUTHOR]

The mechanical properties of a fine-grained (FG) Ti-6Al-4V extra-low interstitial (ELI) alloy were investigated by tensile tests at 298 K and 77 K. The experimental results indicated that, at 77 K, the alloy exhibits a small uniform elongation of 2.65%, but has a fracture elongation of 19.2%, showing superior post-necking elongation. At 298 K, the alloy displays a single dislocation slipping, β→α″ phase transformation occurred, and 6.35% uniform elongation was obtained, whereas the coupling of dislocation slipping and twinning deformation behaviors dominated at 77 K. The limited uniform elongation is attributed to the absence of martensite phase transformation at 77 K, whereas the decent fracture elongation is ascribed to the resistance offered by twinning against plastic instability. [ABSTRACT FROM AUTHOR]

Photovoltaic technology is a prominent source of renewable energy, but maintenance costs and efficiency attenuation of large photovoltaic devices are significant issues due to their vast energy conversion area. To reduce costs and facilitate maintenance, superhydrophobic surfaces with self‐cleaning properties have been developed for photovoltaic glass. In this study, transparent ZnO nanoarrays (NAs) are synthesized on photovoltaic glass, with Eu3+ doping enhancing the ultraviolet radiation resistance of photovoltaic devices and slightly increasing visible transmittance. A TiO2 passivation layer is introduced on the ZnO NAs surface to enhance acid resistance and mitigate corrosion caused by acidic rainwater. Fluoroalkylsilane (POTS) modification achieves superhydrophobicity with a water contact angle of 160.25°, as demonstrated by droplet rolling experiments. Micro‐interaction of superhydrophobic properties is further investigated by force curve measurement using atomic force microscope, showing almost no nanometer water moisture on the superhydrophobic surface, but conspicuous water moisture on the control glass surface. Finally, simulated models and practical silicon crystal solar cells fabricated using the self‐cleaning glass show excellent acid rain resistance, self‐cleaning, and long service life properties, with no power conversion efficiency degeneration during a 40‐day outdoor application test. [ABSTRACT FROM AUTHOR]