SCI論文寫作之Results & Discussion（二）：句與句之間的邏輯！

前言：

上一期內容中，我們主要介紹了Results & Discussion寫法中的一個基本原則：先擺現象，討論完了才能給出結論。今天接著來分享一下Results & Discussion裡面非常重要的一點：邏輯結構問題，希望對大家有所幫助。同時再次邀請對寫作感興趣的，願意分享自己心得和經驗的朋友加入我們（rationalscience@163.com），共同繁榮這個版塊，謝謝！

今日分享：

撰寫學術論文的目的是希望所發現或者發明的內容能夠得到大家認可。因此，受到認可是學術論文最核心的一點。而要想說服別人，很重要的一點必須條理清楚，邏輯嚴密。事實上，任何一篇科學論文的內容都是片面的，只是反映了作者在當時當下所認知的程度，論文中可能還會存在這樣或者那樣的不足。而好的學術論文不是拚命地告訴別人我這個東西已經登峰造極，完美無缺了，而是用數據，用嚴密的邏輯告訴別人：從目前的研究結果，我們可以得出哪些結論，而這些結論對整個領域的發展有哪些重要啟示。

那麼邏輯結構體現在哪些地方呢？句與句之間，段與段之間！今天先介紹下句與句之間的邏輯關係，口說無憑，實例為證：

1. 選用邏輯關係

參考文獻：G. J. Hutchings et al. Science, 2016, 351, 6276.

A limiting factor in achieving high selectivity toward H2O2 with Au-Pd/TiO2 catalysts prepared by the wet impregnation method is that the catalyst nanoparticles exhibit a variation in composition with particle size, with the smallest particles being Pd-rich (傳統催化劑選擇性的局限性). These small Pd-rich NPs are likely to be highly active for H2O2 synthesis and also for its subsequent hydrogenation and decomposition, as has been shown when AuPd catalysts are prepared by colloidal techniques with particle sizes typically 2 to 4 nm (限制選擇性的原因). In the case of the Sn-Pd system, the small Pd-rich NPs are often associated with the amorphous SnOx films（本實驗中的發現）. We postulated that it might be possible to further decrease the H2O2 degradation activity of the catalyst by inducing encapsulation of the ultrasmall Pd-rich NPs by this SnOx film（基於已有理論和現有發現做出的推論）. We therefore used subsequent thermal treatments in an attempt to induce a strong metal-support interaction (SMSI) between the Pd and SnOx layer (根據推論設計的實驗方案). We first added a low-temperature reduction step (200°C, 2 hours, 5% H2 in Ar), which made the catalysts stable to multiple reaction cycles (實驗操作). However, the H2O2 degradation activity increased markedly, from 65 mol kg?1 hour?1 to 300 mol kg?1 hour?1; this rate increase was associated with the reduction of Pd2+ to metallic Pd, as shown by XPS (實驗結果). Metallic Pd is known to be a more effective H2O2 hydrogenation catalyst (對實驗結果的進一步解釋).

這一段一共有9句話，每句話所要表達的意思我都用紅色字體進行了標註。1）首先介紹了傳統催化劑Au-Pd/TiO2在選擇性上的局限性；2）介紹了這種局限性的具體原因；3）本實驗中的發現；4）基於已有理論和現有發現做出的推論；5）根據推論設計的實驗方案；6）根據推論設計的實驗方案；7）實驗操作；8）實驗結果；9）對實驗結果的進一步解釋。可以看得出來，作者在寫作時層層遞進，這是研究思路的內在邏輯。而為了更好地體現這種邏輯，作者在文字上也有所承接（請注意上面一段文字中藍色字體標記的內容）。比如第一句話中引出了Pd rich這個概念，然後第二句話將Pd rich NPs的具體影響進行了進一步地解釋（Pd rich NPs就是這種遞進關係的銜接詞）。而類似的，第三句話，作者還是通過Pd rich NPs從文獻拉回本文的實驗結果。第四句話中更是針對Pd rich NPs提出了推論。類似的第八句和第九句通過metallic Pd將兩個句子銜接在一起，體現出了遞進的關係。

溫馨提示：並列結構是所有邏輯結構中最弱的，如果有遞進關係，請用遞進，如果有因果關係，請用因果關係！文字之間存在邏輯關係，讀者讀起來會覺得很順暢，而相反如果文字之間沒有邏輯關係，只是簡單地羅列，則會顯得很生澀，言之無味。

2. 使用連接詞

另外一種更加簡單地體現句與句之間的邏輯關係是使用連接詞.下面簡單列舉一下一些基本的連接詞：

表示遞進的：then, subsequently, in addition, besides, what is more, moreover, furthermore, in order to...further, 等等；

表示轉折和讓步關係的：but, however, nevertheless, nonetheless, on the contrary, on the other hand, in contrast, instead of, even so, though, although, despite, regardless of, in spite of, as opposed to等等；

表示層次關係的：firstly, first of all, to begin with, secondly...finally, last but not least, afterwards,simultaneously, at the meantime, meanwhile, eventually等等；

表示因果關係的：because, because of this, since, for this reason, thanks to, due to, owing to, seeing that, on account of, therefore，as a result, hence, consequently, accordingly等等；

表示歸納總結的：in conclusion, in summary, in sum, in short，overall,等等;

表示條件關係的：unless, otherwise, only if, if only, suppose that, as soon as, in case that, providing that, given that等等。

這裡依舊舉一個簡單的離子：

參考文獻：Liu, J. and Fan, J. et al., Catal. Sci. Technol., 2014, 4, 441-446.

To further confirm the alloy structure, HRTEM and line-scanning analysis were employed. As shown in Fig. 1c, the lattice fringes of Pt1Pd3 display interplanar spacings of 0.223 and 0.192 nm in the particle, which match well respectively with those of the (111) and the (200) planes of the fcc PtPd alloy. On the other hand, the compositional line profiles of Pt and Pd cross an individual particle shown in Fig. 1d also suggest the NPs to be alloy with homogeneous distributions of elemental Pt/Pd. Moreover, as can be seen from Fig. 1a, the PtPd NPs are well dispersed in the m-SiO2 framework and the sizes of PtPd alloy NPs are rather small with a narrow size distribution (4.1 ± 0.6 nm). The mesoporous SiO2 framework is highly ordered, suggesting that the presence of PtPd NPs does not affect the mesoscopic structure of the oxide support. These results were also confirmed by SAXS data and N2 adsorption–desorption data. As shown in Fig. 2, the interplanar distance of the (100) plane calculated from the SAXS analysis are both 10 nm. Meanwhile, the results from N2 adsorption–desorption data confirm that both Pt1Pd3–m-SiO2 and m-SiO2 have characteristics that are typical of mesoporous materials, and they possess similar BET surface areas (422.8 m2 g?1vs. 439.4 m2 g?1), indicating that the introduction of PtPd has little influence on the structure of the MMOs.

這一段話是典型的對材料微觀結構進行表徵的結果的敘述，是R&D裡面最常見的看圖說話形式。而為了讓這些表徵手段關聯起來，作者採用了很多連接詞（藍色字體部分）。這些連詞的使用可以讓句與句之間關聯更加緊密，從而能夠結合多種表徵手段來綜合說明材料的微觀結構信息。

備註：本文出自浙大化學系范傑教授課題組，第一作者為劉娟娟博士，現為杭州電子科技大學材料與環境工程學院講師。