With the rapid increase of oil production and offshore transportation, the probability of accidental oil leakage is rising. Utilization of superhydrophobic materials constitutes an effective method to solve oil pollution on the water surface. In this study, a modified superhydrophobic sepiolite (SEP) layer was loaded onto the skeleton surface of three-dimensional (3D) porous polyurethane (PU) sponges through a one-step ultrasonic dip-coating process. The as-prepared superhydrophobic sponges can rapidly and selectively absorb multiple oils and nonpolar solvents that are more than 29 times the weight of the sponge, while completely repelling water. In addition, the as-prepared composite material could be reused for oil–water separation for more than 10 times with a high separation efficiency of over 99.45%. The composite material also exhibited robust superhydrophobicity in corrosive liquids and hot water. The results of this research may provide a promising absorbent material that might be used to effectively remove oil spills from the surface of water.

We investigate controllable spatial modulation of circular autofocusing Airy beams, under action of different dynamic linear potentials, both theoretically and numerically. We introduce a novel treatment method in which the circular Airy beam is represented as a superposition of narrow azimuthally-modulated one-dimensional Airy beams that can be analytically treated. The dynamic linear potentials are appropriately designed, so that the autofocusing effect can either be weakened or even eliminated when the linear potential exerts a "pulling" effect on the beam, or if the linear potential exerts a "pushing" effect, the autofocusing effect can be greatly strengthened. Numerical simulations agree with the theoretical results very well.

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Based on the principle of electrochemical reactions, the mechanism of electrochemical micromachining with ultra short voltage pulses was investigated and the theoretical model was developed. The effects of electrode gap and pulse parameters on the result of electrochemical micromachining were discussed. Using the self-developed experimental system, microtool-electrode and the complex microstructures were sequentially machined. Upon the application of ultrashort voltage pulses, the troughs with 20 lm in width were fabricated by / 10 lm tool electrode produced.