Dopmine functionalized mesoporous onion-like silica (DPMS) was synthesized via a biomimetic coating, and lipase Candida sp. 99-125 (LCS) was immobilized in DPMS (LCS@DPMS) by physical adsorption in this study. The DPMS was characterized by SEM, TEM, BET and FT-IR, and it was shown that the DPMS had clear multishell structures with large surface area of 419 m2/g. The activity, pH stability, thermal stability, storage stability, and reusability of the LCS@DPMS were investigated in detail. The stabilities of LCS@DPMS were improved significantly compared to the free lipase and LCS@MS (LCS immobilized in unfunctionalized mesoporous onion-like silica by physical adsorption). All the results indicated that the DPMS had high efficiency and improved stability for lipase immobilization.

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The powerful propulsion system of vessels with double engines and double propellers is commonly used for harbor utility crafts, offshore platform supply vessels and etc.. Their shafting torsional vibration evaluation methods differ from those of one-engine vessels, so it is necessary to use appropriate methods to get scientific evaluation results of the two kinds of shafting. For vessels with double engines and double propellers, the shafting torsional vibration is calculated theoretically by specialized calculation software; a practical scheme is designed and put into use to the real ship testing. The torsional vibration test data of four sets of propulsion shafting of two ships were collected and analyzed. The preliminary results drawn from the analysis can provide references for ship shafting torsional vibration test and analysis.

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