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Abstract: Square SnO2 nano-sheets have been successfully synthesized by a template-free hydrothermal method basing on the reaction between SnCl2 and NaOH in ethanol/water solution. The products have been characterized by X-ray diffraction, scanning electron microscope, and transmission electron microscope. The size and morphology of nano-sheets could be controlled by changing the ratio of ethanol to water. Compared experiments showed that the addition of NaOH was crucial to the formation of SnO2 nano-sheets, and the addition of glycol could induce the formation of cabbage-like structure. The nano-sheets show a strong absorption peak around 330 nm, corresponding to a band gap value of 3.75 eV. This blue shift of the band gap energy was possibly induced by the spatial confinement of excitons in the nano-sheet structures. [Copyright &y& Elsevier]

• The offset characteristics of HTS wireless power transfer (WPT) system was investigated systematically. • The transfer efficiency decreases monotonically with the increase of offset distance. A "flat top" exists in transfer efficiency at short-range radial offset, benefiting the practical applications. • The relationship between load receiving power (LRP) and offset distance is not monotonic. There is an optimal position to reach corresponding maximum LRP. • The HTS WPT system exhibits superior performance in both transfer efficiency and LRP than the copper WPT system. The usage of high-temperature superconducting (HTS) coils in magnetically-coupled resonant wireless power transfer (WPT) systems can considerably improve the transfer efficiency, and hence it attacked great attention. However, there are few studies on offset characteristics in HTS WPT systems. In order to further improve the performance of HTS WPT systems, we have studied experimentally the influences of relative displacement of the coils on the transfer efficiency and load receiving power (LRP) in a magnetically-coupled resonant WPT system. The WPT systems using copper coils and HTS coils were carefully compared. The results show that the transfer efficiency decreases monotonically with the increasing offset. However, there is an optimal position for the LRP to achieve the maximum value. Both the transfer efficiency and LRP of the HTS WPT system are higher than those of the copper WPT system under the same conditions. [ABSTRACT FROM AUTHOR]

Substrate engineering is very significant in the synthesis of the high-temperature superconductor (HTS) coated conductor. Here we design and synthesize several distinct and stable Cerium oxide (CeO 2 ) surface reconstructions which are used to grow epitaxial films of the HTS YBa 2 Cu 3 O 7-δ (YBCO). To identify the influence of annealing and post-annealing surroundings on the nature of nucleation centers, including Ar/5%H 2 , humid Ar/5%H 2 and O 2 in high temperature annealing process, we study the well-controlled structure, surface morphology, crystal constants and surface redox processes of the ceria buffers by using X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS) and field-emission scanning electronic microscopy (FE-SEM), respectively. The ceria film post-annealed under humid Ar/5%H 2 gas shows the best buffer layer properties. Furthermore, the film absorbs more oxygen ions, which appears to contribute to oxygenation of superconductor film. The film is well-suited for ceria model studies as well as a perfect substitute for CeO 2 bulk material. [ABSTRACT FROM AUTHOR]

Abstract: This paper describes the preparation of nano-composite W–La2O3 material by freeze-drying and spark plasma sintering (SPS). The thermionic electron emission capability and surface properties of this material have been investigated. The surface compositions and depth profiles of the prepared material were checked “in situ” by means of AES from 298K to 1573K. Nano-composite W–La2O3 material exhibits good electron emission performance: a saturated emission current density of 1.46Acm−2 can be reached at 1673K with a corresponding work function of 2.79eV. The surface analysis results showed that the good emission capability might be related to an about 10nm surface layer contained excess La caused by diffusion of La from bulk material to the surface. [Copyright &y& Elsevier]

Abstract: Sn2O3-based NO gas sensors were fabricated and investigated in this study. The sensor doped by 1.0at.% antimony had a maximal response to NO gas at 473K. The NO gas with a concentration down to 10ppm can be detected by the sensor without any cross sensitivity to the interfering species such as NO2 and CO. The response speed was shortened about 5.7 times after mixing the 10.0wt.% SnO2 nanoparticles into the 1.0at.% Sn2O3:Sb gas sensor, which was resulted from the formation of Sn2O3–SnO2 hetero-junction. This kind of mixed-oxides gas sensor showed good response to NO gas, weak response to NO2 gas and unstable response to CO gas. [Copyright &y& Elsevier]