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The high infrared emissivity material Gd 1-x Ca x CoO 3 was synthesized using the sol-gel method. The structure and composition of Gd 1-x Ca x CoO 3 were investigated through X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR). Scanning Electron Microscopy (SEM), Energy Dispersive X-ray Spectroscopy (EDS), specific surface area analysis, Brunauer-Emmett-Teller (BET) method for void analysis, and Ultraviolet-Visible-Near-Infrared (UV-Vis-NIR) diffuse reflection spectrum were employed to analyze the surface morphology, elemental composition, specific surface area, pore size distribution, and band gap of the prepared powders. The average infrared emissivity of samples with different doping concentrations at various temperatures (8-14 μm and 3-5 μm) was determined using a dual-band emissivity meter. At room temperature, the infrared emissivity of the doped powders is generally higher, exceeding 0.75 in comparison to the undoped sample powder. As the test temperature increases, the infrared emissivity of all samples shows a significant rise. The infrared emissivity of all samples surpasses 0.91 at 500 °C, with the emissivity of the samples reaching as high as 0.98 8-14μm (0.99 3-5μm) with a Ca doping concentration of 5 %. These findings indicate that Ca-doped GdCoO 3 powder represents a promising high-emissivity material with broad potential in spacecraft thermal control applications. [ABSTRACT FROM AUTHOR]

Yu, Z.; Jia, H., and Huang, X., 2018. Vibration fracture analysis and optimization design of ocean ship transmission shaft. In: Liu, Z.L. and Mi, C. (eds.), Advances in Sustainable Port and Ocean Engineering. Journal of Coastal Research, Special Issue No. 83, pp. 179–183. Coconut Creek (Florida), ISSN 0749-0208. Aiming at solving the fracture problem of a ocean ship transmission shaft. Firstly, the ocean ship transmission shaft was constrained modal analysis by adopting finite elements method, the analysis results show that the first natural frequency was close to its excitation frequency, so the ocean ship transmission shaft resonance would be caused. Secondly, the ocean ship transmission shaft was modal test by adopting hammering method, the test results show that modal test frequency was basically consistent with the modal simulation frequency. Thirdly, the diameter and thickness of ocean ship transmission shaft tube were optimized and analyzed by adopting OptiStruct software, the optimal values were obtained. The ocean ship transmission shaft first two modal frequencies were all outside the excitation range after optimization, so the resonance would be maximally avoided. Lastly, the ocean ship transmission shaft was vehicle test, the test results show that the gearbox shell vibration was greatly reduced, the optimization effect was obvious, so failure problem was successfully solved. [ABSTRACT FROM AUTHOR]