自上世纪60年代至今以来，以Bernstein为代表的教育社会学与以Halliday、Hasan为代表的系统功能语言学不断合作交流，在教育话语理论的研究上持续取得突破。根据系统功能语言学理论，本文以高中人教版化学教科书与剑桥出版社出版的A-level化学教科书为语料来源，对其文本进行语法隐喻和及物性维度上的分析，旨在比较中英高中化学教科书的知识结构异同与来源，以及提出对教学语篇的应用建议。

在对教材中小句进行定量与定性分析后，本文得出的结论如下：第一，从语法隐喻角度，相较于英文教科书，中文教科书使用语法隐喻程度显著地更大。中文化学教科书中出现频率最高的类型是“过程→性状”，英文化学教科书中出现频率最高的类型则是“过程→事物”。此外，两类教科书在语法隐喻其他分类的使用上具有一定差异，总体而言，中文教科书形容词化的隐喻更多，而英文教科书名词化的隐喻更多。导致这种差异的原因可能是，中文中的化学学科术语很多是由英语直译而来，所以不需要额外的名词化。第二，从及物性角度，在两类化学教科书中，高频使用的过程类型均为物质过程与关系过程，旨在描述化学反应过程、事物特点以及对新概念下定义。两类教科书中使用最多的过程均是物质过程与关系过程，使用最少的过程在中文教科书中是言语过程，在英文教科书中是行为过程。物质过程与关系过程有助于阐释和构建较为抽象的化学知识体系，而其他几个过程起到了引导学生思考与观察、指导课堂活动、引入新概念等辅助作用。在英文化学教科书中，图片和符号的使用频率较高，学生可以通过更直观的方式了解新知识，因此对心理、行为等过程的需求有所减少。

由以上分析可知，语法隐喻和及物性在两类教科书中都对垂直知识结构的构建起到了促进作用，且中文教科书的语言结构比英文教科书要复杂。综上所述，中文教科书的知识结构垂直程度要强于英文教科书。通过研究中国高中化学教材与国际同类教材在知识结构上的异同，或可帮助教师及学生更好地掌握非母语学术话语的阅读方式，并优化国内现有教科书。

Since the 1960s, the sociology of education represented by Bernstein and systemic functional linguistics represented by Halliday and Hasan have continuously collaborated and exchanged ideas, achieving breakthroughs in the research of educational discourse theory. Based on SFL, this thesis uses high school chemistry textbooks published by the People’s Education Press and A-level chemistry textbooks published by Cambridge Press as sources to analyze their texts in terms of grammatical metaphor and transitivity dimensions. The aim is to compare the differences and sources of knowledge structure between Chinese and English high school chemistry textbooks, and to propose suggestions for the application of educational discourse.
After quantitatively and qualitatively analyzing the clauses in the textbooks, this thesis draws the following conclusions: First, from the perspective of grammatical metaphors, Chinese textbooks use grammatical metaphors to a significantly greater extent than English textbooks. The most frequent type in Chinese chemistry textbooks is “process → quality”, while the most frequent type in the English chemistry textbook is “process → thing”. In addition, the two kinds of textbooks differ somewhat in their utterance of other categorizations of grammatical metaphors; in general, Chinese textbooks have more adjectivization, while English textbooks have more nominalization. The reason for this difference may be that many of the chemistry subject terms in Chinese are directly translated from English, so there is no need for additional shift into norms. Second, from the perspective of transitivity, in both kinds of chemistry textbooks, the types of processes used with high frequency are material processes and relational processes, which aim at describing the procedures of chemical reactions, the characteristics of things, and defining new concepts. The most frequently used processes in both types of textbooks are material and relational processes, while the least frequently used processes are verbal processes in Chinese textbooks and behavioral processes in English textbooks. The material and relational processes help to explain and build a more abstract body of chemistry knowledge, while the other processes play supporting roles in guiding students to think and observe, directing classroom activities, and introducing new concepts. In English chemistry textbooks, pictures and signs are used more frequently so that students can understand new knowledge in a more intuitive way, thus reducing the need for mental and behavioral processes.
From the above analysis, it can be seen that grammatical metaphor and transitivity contribute to the construction of vertical knowledge structure in both types of textbooks, and the linguistic structure of Chinese textbooks is more complex than that of English textbooks. In conclusion, Chinese textbooks have stronger vertical knowledge structures than English textbooks. By studying the similarities and differences in knowledge structure between Chinese high school chemistry textbooks and their international counterparts, it may help teachers and students to better master the reading of non-native academic discourse and optimize the current textbooks in China.