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A series of nanosized cerium dioxide particles coated with Pluronic P123, poly(vinyl alcohol) (PVA) or titanium oxide are prepared through a sol-gel process. Characterizations reveal sizes of cerium dioxide particles are maintained below 15 nm along with good crystallinity, and their crystal forms could be modulated by calcination. Furthermore, the organic components such as Pluronic P123 and PVA could be incorporated during sol-gel and affect sample porosity, while loading of titanium into cerium dioxide improves acid amount of sol-gel product. Catalysis reveals both PVA and titanium components show obvious and significant thermo- and pH-responsive properties for conversion of d-(−)-fructose into 5-(hydroxymethyl)-furfural, which mean a lot to the future large-scale production of biomass-derived fine chemicals. This work would not only contribute to the development of stimuli-responsive materials, but also show their promising application for conversion of biomass to platform molecules.

A frequency response analysis for a rotating cantilever beam is presented in this study. The equations of motion are derived from Hamilton's principle. An assumed mode method is used for analyzing the vibration frequency characteristic. The equations are transformed into dimensionless forms in which dimensionless parameters are identified. The effects of rotating angular speed are investigated through numerical study. With the coupling effect ignored, the analysis results are consistent with the results obtained by the conventional method. As the angular speed increases, the bending natural frequencies increase monotonically and the stretching natural frequencies decrease. With the coupling effect considered, when the angular speed increases up to a certain value, there exists the warping speed that is in relation with the slenderness ratio.