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International audience; (Tb, Eu)–co-doped ZnO films with about 3 at.% total doping rate were grown by magnetron sputtering on Si substrate. Post annealing treatments were performed at 973–1373 K in continuous nitrogen flow to investigate the transformation of microstructural and optical characteristics by means of X-ray diffraction, transmission electron microscopy, photoluminescence and electroluminescence. For annealing temperatures lower than 1073 K, segregation of Eu and Tb was observed mainly at the film/substrate junction. For temperatures higher than 1173 K, additional phases appeared, namely, Zn2SiO4 and rare earth silicates. For the highest temperature investigated (1373 K), only silica and rare earth silicates remained in the film due to Zn evaporation. PL measurements indicated a very intense Eu emission associated with the presence of rare earth silicate inclusions. Energy transfer from Tb towards Eu was evidenced in this secondary phase. At last, based on these preliminary works, a (Tb, Eu)–co-doped ZnO/Si electroluminescent structure was produced and showed very promising results paving the way for very thin ZnO based light emitting diodes.

In the study, cetyltrimethyl ammonium bromide (CTAB) has been found to have a significant effect on the grain size of zirconia (ZrO 2 ) polycrystalline fibers from a precursor of polyacetylacetonatozirconium (PAZ). A relation between the variation in the grain size of the fibers sintered at 1000 °C for 1 h and CTAB addition has been established by scanning electron microscopy (SEM) and matching the results by a Gaussian Function. The grain size increased firstly and then decreased at an elevated weight percent of CTAB with respect to PAZ. ZrO 2 nucleation at 500 °C and grain growth during thermal treatment between 500 and 1000 °C were investigated by thermal analysis (TG-DTA), X-ray photoelectron spectroscopy (XPS), high resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD). The results indicate that the addition of CTAB accelerated the decomposition of PAZ. The enhanced decomposition promoted ZrO 2 nucleation and the removal of residual carbon. While excess CTAB resulted in the increase of residual carbon on grain surface. The general kinetics of the grain growth was evaluated by Arrhenius equation and the results did matched well with the variation in grain size.

Highly crystalline mesoporous zirconia fibers with high surface area have been prepared by the use of electrospinning combined with precursors method. The obtained precursor fibers were treated in water steam and directly in air at different temperature respectively. Compared with the direct calcination in air, the water steam cannot only promote the crystallization of ZrO 2 but also effectively remove off the organics and prevent the pore structure collapse. Moreover, through adding hydrochloric acid to modify the solution pH value, the obtained t-ZrO 2 fibers treated in water steam at 300 °C have high surface area and large pore volume of 232.70 m 2 g −1 and 0.36 cm 3 g −1 . The formation mechanism of the mesostucture was studied and the schematic was represented. Compared with the previous reports of mesoporous ZrO 2 fibers, the as-synthesized materials exhibited the high crystallinity, large surface area and the long-range order mesostructure.The adsorption of Congo red indicates that the samples have a high adsorption capacity of 103.46 mg g −1 and long-periodic repeated availability.

Ordered mesoporous carbons (OMCs) grafted with poly(N-vinylpyrrolidone) (PVP) was prepared through electrochemically induced surface-initiated atom-transfer radical polymerization (SI-eATRP). The introduction of hydrophilic polymer PVP brushes on the surface of OMCs results in the improvement of wettability and a remarkable increase in the specific capacitance. The results of electrochemical performance of OMCs-PVP show good specific capacitance of 253 F g−1, excellent rate performance and good cycling stability with capacitance retention of 89.6% over 5000 cycles. The PVP modification of OMCs via the SI-eATRP method demonstrates an effective way to improve the wettability and electrochemical properties. Keywords: Ordered mesoporous carbons, SI-eATRP, Polymer brushes, Hydrophilic, Supercapacitor

Taking the high⁃voltage disconnector of the GW46 type as research object, this research first use Solidworks to build its three-dimensional simplified model, then use ABAQUS to simulate the mechanical characteristics of the disconnector over a wide temperature range, analyzing the influence of the clamping force between the dynamic and static contacts on temperature, the contact pressure between the dynamic and static contacts of the high⁃voltage disconnector of the GW46 type increases with the ambient temperature, and the contact pressure becomes smaller. Compared simulation results with experimental data, the error is less than 5%. Analysis shows that using the ABAQUS to simulation analysis of temperature rise of the high⁃voltage disconnector of the GW46 type, it can be determined that the contact pressure between the dynamic and static contacts changes with temperature. It avoids the complexity of the traditional theoretical calculation of query parameters and tedious calculations, and provides strong reference evidence for improving the reliability of the high⁃voltage disconnector of the GW46 type.