The mesoporous and nanorods SnO2 are synthesized by controlling the state of SnCl2·2H2O precursor with SBA-15 as hard template, and the possible formation mechanisms at different assembling modes inside the ordered mesoporous silica templates are proposed. In addition, SnO2 nanoparticles are synthesized by hydrolysis depositing method. The electrochemical tests of as-prepared samples indicate that the reticular stacking structure of the nanorods would limit the Li+ ions to intercalate, but the effect of volume expansion in this case upon cycling is insignificant. The mesostructure SnO2 tends to be stable after partial structural collapse at first few cycles. And the Li+ ions can readily intercalate and de-intercalate into/from its ordered channels structure, which provides a high capacity and an improved cycle property. Although SnO2 nanoparticles deliver high capacity at an early stage, the agglomeration may induce the capacity to drop rapidly after a certain number of cycles.

The free-fall motion of a thin disk with small dimensionless moments of inertia ( ${I}^{\ast } \lt 1{0}^{- 3} $ ) was investigated experimentally. The transition from two-dimensional zigzag motion to three-dimensional spiral motion occurs due to the growth of three-dimensional disturbances. Oscillations in the direction normal to the zigzag plane increase with the development of this instability. At the same time, the oscillation of the nutation angle decreases to zero and the angle remains constant. The effects of initial conditions (release angle) were investigated. Two kinds of transition modes, zigzag–spiral transition and zigzag–spiral–zigzag intermittence transition, were observed to be separated by a critical Reynolds number. In addition, the solution of the generalized Kirchhoff equations shows that the small ${I}^{\ast } $ is responsible for the growth of disturbances in the third dimension (perpendicular to the planar motion).

This paper describes an experimental investigation of the dynamics of a freely falling thin circular disk in still water. The flow patterns of the disk zigzag motion are studied using dye visualization and particle image velocimetry. Time-resolved disk motions with six degrees of freedom are obtained with a stereoscopic vision method. The flow separation and vortex shedding are found to change with the Reynolds number, $\mathit{Re}$ . At high Reynolds numbers a new dipole vortex is shed that is significantly different from Kármán-type vortices. The vortical structures are mainly composed of leading-edge vortices, a counter-rotating vortex pair and secondary trailing-edge vortices. The amplitude of the horizontal oscillation is also dependent on the Reynolds number with a critical Reynolds number ${\mathit{Re}}_{cr} \approx 2000$ , where the oscillatory amplitude is proportional to $\mathit{Re}$ for $\mathit{Re}\lt {\mathit{Re}}_{cr} $ , but becomes invariant for $\mathit{Re}\gt {\mathit{Re}}_{cr} $ . Three-dimensional dipolar vortices were also observed experimentally.

A new varistor system of SnO2·Ni2O3·Nb2O5 exhibits the relative dissatisfactory physical and electrical properties. The effect of cobalt oxide on the properties of the SnO2·Ni2O3·Nb2O5 varistors was investigated by measuring the densities, permittivities, the current-voltage properties and the properties of the defect barriers. It is found that the sample doped with 0.25 mol% Co2O3 exhibits the abnormal poorer electrical properties than the samples without Co2O3 dopants. However, the sample doped with 6.0 mol% Co2O3 exhibits the highest nonlinear coefficient ( $\alpha=17.24$ ) and reference electrical field ( $E_{\rm B}=561$ V/mm), although the sample doped with 1.0 mol% Co2O3 exhibits the highest densities ( $\rho =6.87$ g/cm3) and permittivities. The sample with 6.0 mol% Co2O3 bears the highest barriers, but the sample with 1.0 mol% Co2O3 shows the narrowest barriers. The investigation of the sintering temperature shows that the samples sintered at 1450 °C exhibit the better physical and electrical properties. The results were discussed and the defect barrier model was also introduced to explain.

Environmental and internal-hydrogen embrittlements in stress-relieved and recrystallized Ni−16.5Al−8Cr−0.8Hf−0.1B−0.03Y (at. %) have been studied. The stress-relieved Ni3Al-based alloy showed environmental embrittlement when tested in air or in hydrogen gas. The embrittlement is more severe in hydrogen gas than that in air. The recrystallized Ni3Al-based alloy was not susceptible to air, but it was embrittled severely by hydrogen gas and exhibited not only a grain interior but a severer grain boundary embrittlement. When tested in air, the stress-relieved Ni3Al was insensitive to internal hydrogen; however, the recrystallized Ni3Al showed a certain susceptibility to internal hydrogen. With increasing the internal hydrogen content in the alloy, the ductility of the recrystallized Ni3Al decreased steadily and a certain degree of grain boundary embrittlement was observed.