Research On The Coherence Of Multimodal Discourse Of Genre Hybridity—A Case Study Of Popular Science Articles On Wechat Platform

With the rapid development of the Internet and communication technology,popular science information has evolved from traditional media forms into online new media ones with richer semantic contents.On the new social media platform—We Chat public accounts,popular science articles emerge in the form of multimodal and hybridized genres.Previous studies have mostly centered on the comparison with traditional media.There are few enquiries into the discourse coherence mechanism of PSAs on social platforms from the linguistic perspective.The thesis,adopting a systemic functional point of view,intends to construct an analytical model for multimodal discourse of hybridized genre.Taking PSAs on We Chat public accounts as an example,it aims to probe into the hybridity modes of the macrogenre and how varied elemental genres and visual-verbal resources are integrated into a coherent whole for the purpose of science dissemination.Drawing on Martin’s theory on genre and genre hybridity as well as Matthiessen’s typology on genre,the thesis has unveiled the regular hybridity modes of PSAs.By means of Rhetorical Relation Theory,it has also uncovered the regularity in generic structures and rhetorical structure constructions of the explaining genre,revealing its logico-semantic representations at the semantic stratum and how visual-verbal resources are orchestrated coherently through rhetorical relations.Through the analysis of 36 PSAs on We Chat platform,this thesis has made the following findings:(a)The subject-matter relations of the nucleus-satellite category dominate the logico-semantic construction of the discourse,such as ELABORATION,SOLUTIONHOOD and INTERPRETATION,while representational relations,like BACKGROUND,EVIDENCE,PREPERATION,and multinuclear relations such as JOINT,ADDITION and CONTRAST account for small proportions.The rhetorical composition is compatible with the generic features of PSAs;(b)The interaction of visual-verbal resources for textual coherence manifests certain universality and particularities.Pictorial resources are often subordinate to the body text,and so are captions to visual images.Both can achieve functions of ELABORATION,IDENTIFICATION and EVALUATION.In terms of particularities,visual resources can provide evidence and location to the body text,while captions further supplement property information and restate visual contents.(c)The rhetorical combination of the body text and visual pictures that carry different ideational meanings presents differences;(d)The study has identified four typical explaining subgenres,and their rhetorical structures present similarities: the whole text can be divided into two structural spans—phenomenon identification and feature explanation.The second level is about the different features of entities linked by JOINT or ADDITION relations.Specific descriptions of features appear further down in the structure of“statement + elaboration” or “question + solution”.(e)Eight elemental genres are identified in PSAs and are hybridized differently into the macrogenre through varied rhetorical relations.For instance,genres of experience sharing,value sharing,chronicling,and arguing are often integrated into the text through modes of embedding or fused mixing via BACKGROUND relation to capture readers’ interests.Advising genre tend to appear in metaphorization with inventorying genre as its superficial form to achieve persuasion.