充当英语翻译

充当一个重要角色；充当，扮演；角色

A similar explanation might serve for the slow rate of charge injection into stilbene-capped hairpins where several AT base pairs separate the photoexcited stilbene hole donor from a guanine hole acceptor. Stilbene-4,4′-dicarboxamide incorporated as a bridging and capping element in short ATcontaining hairpins (Sa-AT) has an extended nanosecond lifetime and hence higher fluorescence quantum yield versus the free dye, but a single GC pair close to the stilbene。Figure 5. (A) The rate of coherent deazaguanine (ZG) oxidationby ethidium bromide is the same over short distances for both theflexible linkage (Et1, black, both CT rates shown) and the rigidlinkage (Et2, gray).For two intervening nucleotides, a sharp dropin rate is observed for the rigid Et+, but the rate is unaffected for the flexible Et+. (B) This steep drop in rate over short distances is consistent with that observed for oxidation of guanine by a photoinduced sugar radical (circles)207 and CT between hairpincapping stilbenes (squares, photooxidation of stilbene 4,4′-diether(Sd) by stilbene-4,4′-dicarboxamide (Sa))125 and has been attributed to a crossover between coherent superexchange and incoherent hopping. In the latter case, comparison of injection and hole arrival rates supports superexchange for one or two intervening base pairs and hopping for three or more base pairs between the stilbenes. 类似的解释可能服务很慢的电荷注入发夹有数以碱基对分离从鸟嘌呤洞孔捐赠者的受体。组建,能在短和限制元素发夹,从而延长了十亿分之一秒的一生与高荧光量子产量,但一个免费的染料毛细管气相色谱法对接近。 图5。(一)。连贯的速度(导报)氧化 通过溴化是相同的距离 灵活的连接(Et1,黑色,两次CT率)和僵化 Et2联动,灰色)。(二介入核苷酸,急剧下降 在利率是为刚性等,但速度+不受影响的柔性等+。(B)。这险峻的近距离观察到的一致的鸟嘌呤氧化由光诱导糖激进(圈)207和CT之间的发夹，盖广场中。 被归因于一间和非相干交叉跳。在后一种情况下,比较注射和孔到达率，支持的一个或两个介入碱基对和跳跃三个或更多的碱基对之间。

应该是占领先地位吧

建议楼主不要来这里找翻译高手，一般情况下，像你这样的文章连我这样有一些翻译经验，词汇量达到一万五的的人做这篇都需要20分钟，何况其他人。你给的分数太少了，另外这里也没有很优秀的翻译， 建议你去 翻译中国或者译网情深上去看看，他们可以帮到你。记住了，天下没有免费的午餐。

在促进长江流域的经济发展中，上海发挥了重要的作用（扮演了重要的角色）。Play a leading role in... 这是个固定短语，字典里查的到，表示“在...起重要作用，或 在...中扮演重要角色”play 的意思很广泛，在这儿要放在短语中才好理解。希望你能明白。