In situ x-ray diffraction and x-ray absorption fine structure techniques were used to study the structural change of ordered Co nanowire array with temperature. The results show that the Co nanowires are polycrystalline with hexagonal close packed structure without phase change up until 700 °C. A nonlinear thermal expansion behavior has been found and can be well described by a quadratic equation with the first-order thermal expansion coefficient of 4.3×10−6/°C and the second-order thermal expansion coefficient of 5.9×10−9/°C. The mechanism of this nonlinear thermal expansion behavior is discussed.

Cubic germanium dioxide (GeO2) nanoparticles coated by sodium bis(2-ethylhexyl) sulfosuccinate (AOT) were synthesized with a reverse micelle technique. In situ heating extended X-ray absorption fine-structure technique was used to investigate the change of the local atomic structure and electronic structure around germanium. A direct formation of Ge−S bond was found from GeO2 at high temperature and ambient pressure. This Ge−S bond was identified to be temperature-dependent. The change of the local structure with heating is discussed. This study provides a routine process to synthesize GeS2 from GeO2 at higher temperature and ambient pressure.

This paper presents a novel approach for simulating the dynamic coupling between a tree and raindrops based on physical deformation and fluid simulation. By the approach, tree animation in the rain can be simulated in a two-resolution way: branch motion and leaf motion. The branch is represented by the Euler-Bernoulli beam model, and the leaf petiole is represented by the three-prism elastic model. Interaction coupling liquid motion on the hydrophilic surface with a flexible petiole is well implemented by a special design. To simplify the computation process, instead of the computation-intensive three-dimensional Navier-Stokes equations, shallow water equations are used to simulate the water dynamics together with the whole leaf deformation. Simulation has been also made to various phenomena incurred from the interactive coupling. These include, among others, part of impacting raindrops splashing into the air with the remaining flowing along the slant of the leaf and merging into larger ones or hanging on the blade boundary, with the leaf rebounding and vibrating after the drops fall off the leaf. A level-of-detail approach is exploited to accelerate rendering in views of different distances. The experimental results illustrate that the approach can be applied to efficiently generate realistic details of the interactive coupling between a tree and raindrops.