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作者词汇基础扎实；语句间的衔接成分用的不错，同时文章中的过程性词汇很丰富；作者在句法层面做的很棒。
Cu(acac)2/n-Bu4NBr/Fe3O4@MCM-41 was recovered by a permanent magnet after the reaction and reused in the next run without further treatment. The results in Table 7 show that the catalytic performance of Cu(acac)2/n-Bu4NBr/Fe3O4@MCM-41 nearly kept constant during the initial 3 cycles in terms of the conversion of SO, the selectivity and yield towards SC, which changed in the small range of 89.1–92.9%, 92.4–94.2% and 82.3–87.5%, respectively. However, sharp decrease was observed for the fourth run. The AAS analysis revealed that Cu loading changed in a small range from 2.4 to 2.3 wt.% during the recycled procedures. However, IC analysis showed that Br loading in the recovered catalyst sharply decreased from 6.1 to 2.4 wt.% after the third run although 5.9 and 5.5 wt.% Br loading were observed after the first and second run. The fourth run was then performed by supplementing additional 0.15 mmol n-Bu4NBr, around one third of the first run, without changing other reaction conditions. As expected, the yield of SC at 78.2%, closing to the third run, was obtained. So it is reasonable to conclude that the loss in the catalytic activity was mainly caused by the leaching of n-Bu4NBr. It can be ascribed to n-Bu4NBr mainly anchored on the surface of the mixed support, as shown in Fig. 3 and surface composition obtained by XPS analysis, thus resulting in easier leach of Br than that of Cu.
