In this study, a good core-shell heterostructure of Pt NPs@UiO-66 was fabricated by encapsulating presynthesized platinum nanoparticles (Pt NPs) into the host matrix of UiO-66 which possesses the slender triangular windows with a diameter of 6 Å. The transmission electron microscopy images exhibited that the number of the encapsulated Pt NPs and the crystalline morphology of as-synthesized core-shell heterostructure samples had a series of changes with increasing the volume of the injected Pt NPs precursor solution. Among these samples, the Pt NPs@UiO-66-2 sample had a good crystalline morphology with several well-dispersed Pt NPs encapsulated in UiO-66 frameworks. But there were no obvious Pt NPs observed in the Pt NPs@UiO-66-1 sample, and for the Pt NPs@UiO-66-3 sample, the number of Pt NPs encapsulated in UiO-66 matrix notably reduced and the metal organic framework (MOF) crystals became small and aggregated. The electrochemical measurements showed that the Pt NPs@UiO-66-2 sample modified glass carbon electrode (GCE) presented a remarkable electrocatalytic activity toward hydrogen peroxide (H2O2) oxidation, including an excellent anti-interference performance even if the concentration of the interference species was the same as the H2O2, an extended linear range from 5 μM to 14.75 mM, a low detection limit, as well as good stability and reproducibility. The results indicate the superiority of MOFs in H2O2 detection. And more importantly, it will provide a new opportunity to promote the anti-interference performance of the nonenzyme electrochemical sensors.

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In this paper, tests on viscoelastic (VE) dampers are carried out, and the results indicate that VE dampers have high energy dissipation capacity and excellent anti-fatigue properties. To clarify the mechanical properties of VE dampers, a new mathematical model, named the equivalent fractional Kelvin model, which considers temperature and frequency effects simultaneously, is proposed. The numerical results using this model are in good agreement with experimental results. Then, through analysis on a five-story reinforced concrete frame structure with and without VE dampers, it is found that the seismic responses of the structure with VE dampers are significantly reduced and VE dampers have high energy dissipation capacity.

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