1 Introduction

Metaphor plays an important role in academic discourse, not only as a rhetorical device and thinking mechanism, but also having a significant impact on academic writing. Its frequency of use in academic texts is higher than other types of texts, indicating its importance in academic communication. The cultivation of metaphorical awareness and ability is crucial for academic growth, and the lack of these abilities may lead to academic communication barriers. This study aims to systematically organize the latest developments in metaphor research in academic terminology, explore its development trends, theoretical perspectives, research objects, content, and methods.

2 Data Retrieval and Analysis

This article introduces the application of the scope review methodology framework in metaphor research in academic discourse, emphasizing its advantages in summarizing research scope in specific fields and integrating differential research. Research was conducted through searching on CNKI and WoS databases, limiting Chinese CSSCI and foreign SSCI articles, and using both Chinese and English search terms for literature retrieval. Literature screening is divided into three stages: retrieval, screening, and review, ultimately selecting CSSCI and SSCI journal articles that meet the criteria. The integrated analysis section adopts a bottom-up coding method to conduct three-level coding on the literature and extract its characteristics.

3 Research findings and discussions

Summarized the development trend, theoretical perspective, research object, research content, research methods, and existing research results of metaphor research in academic terminology. From 2007 to 2023, the number of relevant literature has shown an upward trend, with a significant increase in 2023. Theoretical perspectives mainly include cognitive linguistics, systemic functional linguistics, and sociolinguistics, with some studies adopting perspectives such as pragmatics, psychology, and visual semiotics. The research subjects involve academic discourse and metaphor, including different modalities, domains, genres, disciplines, and metaphor types. The research covers the functions, disciplinary characteristics, genre features, and factors that influence the understanding and production of metaphors. The research methods include quantitative research, qualitative research, and mixed methods research. The data collection methods are diverse, and metaphor recognition is the core of the analysis. Existing research results show that metaphor has cognitive, rhetorical, and discourse functions in academic discourse, with significant disciplinary and genre characteristics. Factors that affect metaphor understanding and production include personal and environmental factors.

4 Future research directions

The research on metaphor in future academic discourse will be conducted from four directions: 1 Expand theoretical perspectives, combining cognitive linguistics, systemic functional linguistics, sociolinguistics, etc., to explore the psychological mechanisms of metaphor from the perspective of psycholinguistics; 2. Enrich the research subjects, pay attention to the metaphorical characteristics of different academic communication contexts and academic genres, such as journal articles, dissertations, etc; 3. Expand research content and investigate the influence of academic experience, language proficiency, native language factors, etc. on metaphor production and understanding; 4. Optimize research methods and designs, such as using experimental methods, combining corpora with experiments, and improving metaphor recognition techniques.

5 Conclusion

By using the scope review method, 40 CSSCI and SSCI source journal articles were analyzed, and the current status of academic discourse metaphor research was summarized. Research shows that metaphorical functions, disciplines, genres, domain characteristics, and factors influencing understanding and output are currently hot topics in research. However, the diversity of theoretical perspectives and research subjects needs to be improved. Future research should expand theoretical perspectives, increase research subject diversity, and delve into the genre specificity and influencing factors of metaphor. As an important branch of English for Specific Purposes, the study of metaphors in academic English is of great significance for ESP teaching. Metaphors can reflect the characteristics of a subject and reflect learners' second language metaphorical ability, language proficiency, and cognitive ability. Teaching inspirations include: exploring subject metaphors and cultivating subject metaphor awareness; Observing the metaphorical output of different academic subjects and enhancing the diversity of teaching materials; Pay attention to oral and visual metaphors, enhance diverse perception and communication skills; Adjusting teaching methods based on influencing factors to enhance metaphorical understanding and production abilities; Develop critical analytical skills in metaphorical language. The study of academic discourse metaphor can help improve learners' understanding and expression abilities in academic discourse, providing theoretical and practical insights for ESP teaching.