The kelp knots are the main product for exporting and earning foreign exchange in Chinese kelp culture provinces, but there are no mechanical processing devices. Therefore, the kelp knots are usually tied manually. Based on the principle of bionics, this paper offered an automatic knotting machine which could make the kelp forming a circle and passing through it to form a knot with the logic circuit. The test verified that this knotting machine was able to complete the operational requirements for kelp knotting accurately, which showed that this design was reasonable and feasible, and had the value of promotion and application after further optimization. It could also provide certain reference for the design and application of relevant knotting equipment.

For the risk problem of oil spill on the sea,and in order to predict the diffusion drift trajectory of oil spill effectively,this study refered to domestic and foreign oil spill simulation methods and selected the particle tracking method to simulate and predict the oil spill drift trajectory.Based on the study of the tidal current field in Sansha Bay,Ningde City,assuming that light oil leakage occurred in the sea area of Baima Gang,using the oil particle model and considering the interaction of wind field and flow field, this study simulated and analyzed the drift trajectory of spilled oil under different wind conditions and calculated its influence range.The simulation results showed that:firstly,the track of oil spill migration and diffusion was affected by the interaction of tidal flow field and wind field;secondly,the oil spill in Baima Gang was obviously affected by the wind direction,and the influence scope of migration and diffusion was mainly concentrated on the top of the bay,and the influence area was small under southeast wind conditions,but it could be distributed to the bay area,with a large impact area under northeast wind conditions;meanwhile,the results also indicated that the “oil particle” model could invert the oil spill diffusion trend in Sansha Bay,and provide technical support for future research on fishery resource loss assessment of oil spill accidents,or for the improvement of emergency management system among Baima Gang district.