This work reports a hard self-template method to synthesize core/shell like Fe3O4@C microparticles, in which the Pd nanocrystals can be alternatively incorporated into the carbon shells. The Fe3O4@polyaniline core/shell microspheres were first synthesized as the precursor by in situ polymerization of aniline onto the surface of the Fe3O4 microspheres. In a subsequent carbonization of the precursor under a vacuum oven, the Fe3O4 core was preserved and the polyaniline shell transferred into carbon shells enveloping the magnetic sphere, forming magnetic Fe3O4@C microspheres. The Pd ions could be impregnated into the polyaniline shell, and thus the obtained composites were transformed into Fe3O4@C/Pd microspheres under the same vacuum heating progress. The as-obtained system demonstrates superparamagnetic characteristics, which would benefit its potential application in nanocatalysts. This strategy provides an efficient approach for tailoring core/shell materials with desired functionalities and structures by adjusting the precursors and structure-directing agents.

Novel SrAl2O4:Eu2+, Dy3+/SiO2-coated red-emitting coumarin color converter (SiO2@RECC)/polyamide 6 (PA6) luminous fibers with warm-toned luminescence color were prepared on the basis of the energy transfer and color conversion from SrAl2O4:Eu2+, Dy3+ to RECC. The mass concentrations of RECC used in the fibers were adjusted to obtain different luminescence colors. Scanning electron microscopy images, photoluminescence (PL) emission spectra, RGB color coordinates, luminescence photos, and luminescence lifetimes were analyzed. Results demonstrated that the PL emission spectra of luminous fibers contain two emission peaks in the range of 475–700 nm. The increase in RECC concentration contributed to the gradual redshift of the second emission peak, and the ratio of the second emission maximum to the first emission maximum also increased gradually. The luminescence color of the fibers shifted gradually toward red in the dark. Moreover, the fibers showed light yellow, yellow, orange, and orange-reddish luminescence in the dark when the mass concentrations of RECC were fixed at 0.1%, 0.6%, 1.0%, and 1.4%, correspondingly. The luminescence lifetimes of the fibers can be sustained for at least 13,288 s. The prepared warm-toned SrAl2O4:Eu2+, Dy3+/SiO2@RECC/PA6 luminous fibers have considerable application prospects, given their excellent luminescence properties.

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The pre-stressed friction loss formula in bending channel recommended by Bridge Rules was based on the uniform distribution hypothesis of contact pressure. From some conflicts in application of the formula, the non-uniform distribution law of the contact pressure was revealed. On the basis of elastic contact analysis, two types of non-uniform distribution hypothesis were proposed, including cosine and second-degree parabola distribution. Then the contact positive pressure expressions were derived respectively and the frictional resistance was calculated to compare with the calculated value under the uniform distribution. The results indicate that the friction resistance under any non-uniform distribution of positive pressure is less than under the uniform distribution. So the uniform distribution assumption of contact pressure does not cause Bridge Specifications formula underestimate friction loss. It is necessary to do further research on the applicability of Coulomb’s law under the contact conditions in the curved channel.

As the third generation solar cells, quantum dot sensitized solar cells (QDSSC) has received wide attention from researchers because of its high theoretical energy conversion efficiency and low production costs. The preparation of CdS quantum dots for TiO2 inverse opal based QDSSC by successive ionic layer absorption and reaction (SILAR) was investigated. The optimized number of SILAR cycle and ionic reaction time was obtained by the analysis of absorption spectra.