The world faces severe environmental, human and ecological problems when major oil spills and organic discharges are released into the environment. And so it is imperative to develop tools and high performance innovative materials that can efficiently absorb these organic discharges. Furthermore, green, facile methods to produce these advanced materials are also needed. In this paper, we demonstrate a novel porous supersponge based on melamine coated with hBN. This superhydrophobic sponge (with a contact angle >150°) exhibits excellent absorption performance for oils and organic solvents, including good selectivity, high capacity (up to 175 g·g−1) and extraordinary recyclability (less than 20% decline after 30 cycles of absorption/squeezing). The synthetic procedure required only ultrasonication and immersion of the sponge in aqueous hBN solution, being a green, cost-effective and scalable production methodology. By virtue of the straightforward and cost-effective fabrication method, along with the excellent absorption performance, hBN-decorated sponges have great promise for real world practical application in the field of oil spills and organic leakage cleanup.

A two-dimensional finite wedge entering water obliquely in freefall with three degrees of freedom is considered through the velocity potential theory for the incompressible liquid. The problem is solved by using the boundary element method in the time domain. The scheme of the stretched coordinate system is adopted at the initial stages when only a small part of the wedge near its tip has entered water. The auxiliary function method is adopted to decouple the nonlinear mutual dependence between the body motions in three degrees of freedom and the fluid flow.When the liquid has detached from the knuckle of the wedge, the free jet is treated through the momentum equation.The developed method is verified through existing results for one degree of freedom in vertical motion. Various case studies are undertaken for a wedge entering water vertically, obliquely and with rotational angles. Results are provided the accelerations, velocities, pressure distribution and free surface deformation, and the physical implications are discussed.

Unlike crystals producing sharp peaks under the x-ray diffraction, disordered materials show slowly varying patterns presenting little structural information. This is due to the fact that only the scattering intensity can be recorded, and the loss of the phase information makes the Fourier inversion of the amplitude impossible. However, when an amorphous sample is placed on a crystal, the x-ray intensity diffracted by the assembly can produce a hologram which contains the spatial modulation of both density functions. Therefore, with known crystal structure the electron density of the amorphous specimen can be resolved by holographic technique. Moreover, it is found that only the amorphous scattering data are needed, and the Bragg peak(s) can be dropped. This gives the scheme the same noise tolerance as by the ordinary amorphous diffraction.

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The hydrodynamic problem of a breaking wave impacting on a floating body with air bubble effect is modelled based on the incompressible velocity potential theory, which is solved using the boundary element method in the time domain. To avoid the numerical inaccuracies due to the sharp temporal and spatial variations of velocity and pressure at the initial stage of impact, a dual system is adopted. The simulation close to the impact zone is conducted in a stretched coordinate system, while away from the impact zone the deformation and propagation of incoming overturning wave is simulated in the physical coordinate system. The continuities of both pressure and velocity are enforced at the interface of two zones. When the impact zone is no longer small, the dual systems will be merged and the simulation will be undertaken in one single domain. The air bubble trapped between the breaking wave and the solid surface is taken into account based on the assumption that the trapped air undergoes an adiabatic process. An auxiliary function method is used to decouple the nonlinear mutual dependence of fluid loading, body motion and bubble deformation. Simulations are undertaken for cases related to breaking wave impact in various engineering problems, including a solid coastal wall, a freely floating ship cross section, a floating breakwater and a tension leg platform. Detailed results for pressure, free surface profile, bubble deformation and body motion are provided, and their physical implications are discussed.