撰文：邹世辉 所属专栏：研之成理写作实验室前言： 在Introduction中，我们通常需要对已发表文献的结果进行总结并提炼出其中值得研究的科学问题。而非常常见的一种情况是人们对于某一科学问题还没有定论，不同的人有不同的观点，那么在写作时，有哪些常见的句型可以应用这种情景呢？ 一般而言，这种情况下采用总分式进行写作，先提出论点（总：指出存在分歧），然后分别陈述论据（介绍分歧的具体内容）。 示例：(总)The mechanism with which tungsten oxide can activate the vanadium oxy-centers for the SCR is still matter of debate.（分）Some authors pointed out that tungsten oxide gives rise to stronger Brønsted acid sites, whose presence favors the reaction. Other authors proposed that the SCR reaction needs two sites, and WO3 can offer the presence of a second site. Alternatively, it has been suggested that the V2O5–WO3/TiO2 solid presents quite peculiar electronic features, involving the semiconducting nature of titania and the similarity of the d levels of tungsten, vanadium and titanium. 参考文献：Appl. Catal. B: Environ. 1998, 18, 1-36
常用的句式有：A. The mechanism with which tungsten oxide can activate the vanadium oxy-centers for the SCR is still matter of debate.（Appl. Catal. B: Environ. 1998, 18, 1-36） 类似：Low-temperature CO oxidation by supported Au nanoparticles, first reported by Haruta et al., is interesting from a fundamental point of view, as the exact origin of the catalytic activity is much debated.（J. Phys. Chem. C, 2008, 112 (17), 6900–6906） As heterogeneous catalysts
they have not proved amenable to intimate study, and even to this
day there remains an on-going debate about the oxidation state
of the active chromium centres. (Chem. Commun., 1998, 1651-1652) B. Charge transport in mesoporous systems is under keen debate today and several interpretations based on the Montrol–Scher model for random displacement of charge carriers in disordered solids have been advanced. （J. Photochem. Photobio. A: Chem. 2004, 164, 3-14） 变形：Debate has long prevailed as to whether...
类似：The controversy about scientific evidence for X has raged unabated for over a century. C. Although considerable
progress has been made, particularly in the last
five years, this has been accompanied by much
debate. In addition, some unexpected and intriguing
findings have emerged. （Biochem Soc Trans. 1995，23(2):321-4.） D. Cu-containing zeolites, mainly ZSM-5, have received much attention due to their high activity for the SCR reaction and for the decomposition of NO. The type of active Cu species in these reactions has been a much debated topic; both isolated Cu ions and dimeric Cu species have been proposed as the active site. In addition, evidence for the importance of Cu2+/Cu+ redox cycle has been presented. (Chem. Commun., 2011, 47, 800-802) E. It is an open question if catalytic coherence is
associated with a cost of ordered energy. (Phys. Rev. Lett. 2014, 113, 150402) F. To date, there has been little agreement in the way laboratories prepare, measure, and correct for uncontrolled hydrogen isotopic exchange in complex organic samples, resulting in incomparable δD results. Previously, nitration and preparative equilibration procedures aimed at controlling exchangeable hydrogen were designed for specific sample types (e.g. cellulose, chitin) but required extensive processing of individual samples. Here we describe a static, high-temperature preparative equilibration technique that provides increased sample throughput and δD measurements that are not compromised by uncontrolled isotopic exchange. （Environ. Sci. Technol., 2000, 34 (11), 2354–2360） 变形：There has been disagreement concerning the reactions that must be included in the kinetic model of the process. （Appl. Catal. A: Gen. 1999, 179,21-29） G.The kinetic parameters for carbon dioxide hydration catalysis by carbonic anhydrase (EC 4.2.1.1) present an apparent paradox.The assumption of H2CO3 as the hydration product requires the rate of recombination of H2CO3 with enzyme to be faster than the diffusion limit. The alternative assumption of HCO3- as the product of hydration likewise requires active-site ionization rates to exceed the diffusion limit. (Proc. Nat. Acad. Sci. USA,1973, 70, 1986-1989) H. This concept has been challenged by numerous observations that the cells within a terminally differentiated epithelium can indeed change their phenotype through activation of an EMT program, which enables transdifferentiation, resulting in the conversion of epithelial cells to mesenchymal derivatives during development and adulthood. 类似1：However, the role of myelin inhibitors has
been challenged by a study in which micro-injected adult peripheral
sensory neurons were capable of extending axons along myelin
tracts in the intact adult rat spinal cord. (Nature, 2000, 407, 963) 类似2：The debate about X has gained fresh prominence with many arguing that ... I. Contradictory findings
have appeared in the literature regarding the inhibition
of FIFo ATPases by A1 and F combined. (Arch Microbiol (1990) 155:22-27) 类似1：More recently, literature has emerged that offers contradictory findings about 类似2：It is therefore curious that quite different and contradictory findings
have been published about reaction (I). (J. Chem. SOC., Faraday Trans. I, 1983,79, 1649-1658) 类似3：This contradicts the results of Long
and Yang, who found the same reactivity of NH4+ ions with an equimolar
NO-2NO2 ratio on H-ZSM-5 and Fe-ZSM-5 at 200 oC. 类似4：These findings are contradictory to results onFe-ZSM-5 zeolites, which showed an increase in the amount of reduced
Fe2+ species when heated to 700 oC. (Catalysis Reviews, 2008, 50:4, 492-531) J. Two conflicting interpretations of this phenomenon have been proposed: a surface pH effect and a pH–dependent modification of the conformation of the adsorbed enzyme. (European Journal of Soil Science, 1996, 47: 511–522) 类似1：The relationship between X and Y has attracted conflicting interpretations from … K. While examples of well-characterized mononuclear iron(IV)–oxo complexes now abound, and advances in our understanding of their reactivity have been substantial, much less is known about copper congeners having a [CuO]+ core (3). Many proposals for the involvement of [CuO]+ species, as well as the protonated version [CuOH]2+ (4), in oxidation reactions have appeared, but supporting evidence is sparse and indirect, and such species have not been observed directly as discrete complexes in condensed phase. (Acc. Chem. Res., 2015, 48 (7), 2126–2131)