本文在篇章语法理论框架下考察事物说明语篇的篇章语法现象。本文分为七章，具体内容如下：

第一章是“绪论”。这一章主要明确本文的研究对象，梳理已有的研究，介绍本文的理论背景、研究内容、研究方法和语料来源。

第二章到第六章是本文的主要内容，整体上沿着从宏观到微观、从抽象到具体的思路研究事物说明语篇的篇章语法现象。

第二章是“事物说明语篇的篇章特点”。本章主要从施事主导性、时间序列性、客观性、描写性、实体性五个方面界定事物说明语篇的特征，事物说明语篇的篇章特征表现为：[-施事主导性][-时间序列性][+客观性][+描写性][+实体性]。  

第三章是“事物说明语篇的篇章结构”。本章从语篇整体着眼，把事物说明语篇的结构分为引入、主干和结尾三个部分。其中主干是语篇的必有部分，引入和结尾是语篇的可有部分。主干部分在宏观说明顺序、中观说明顺序和微观说明顺序方面都主要按照空间顺序、时间顺序或逻辑顺序展开对说明对象的介绍。

第四章是“事物说明语篇说明对象的表征”。本章从说明对象着眼，分说明对象与标题、说明对象的引入、说明对象的推进和说明对象的隐退四个方面考察语篇的推进。说明对象通常会出现在语篇标题中。说明对象在语篇正文第一次出现时前面往往具有铺垫成分。说明对象的推进分为同一说明对象集中推进和不同说明对象递相推进两种，第一种推进中说明对象的指称呈现为从繁到简的变化特征，后一种推进中通常由说明对象系统内上层说明对象引入下层说明对象；说明对象推进形式的整体特征在语篇内部类型中存在着差异。说明对象的隐退分为借助说明对象隐退和借助说明对象之外的相关内容隐退两种。

第五章是“事物说明语篇的‘前景-背景’与‘及物性’”。本章从语义、句法和表达方式等多个角度出发考察事物说明语篇的前景-背景和及物性特征。考察发现事物说明语篇前景体现为[+所介绍内容的系统性][+主语的一致性][+说明对象主体性][+对描写或说明的依赖性][+客观存在性][+空间性][+状态性][-时间序列性]，背景体现为[-所介绍内容的系统性][-主语的一致性][-说明对象主体性][+/-对描写或说明的依赖性][+/-客观存在性][+/-空间性][+/-状态性][+/-时间序列性]。事物说明语篇整体上呈低及物性，其中前景的低及物性尤为凸显，背景的及物性略高于前景，但整体上呈非高及物性。

第六章是“不同句式的篇章适用性”。本章深入语篇内部考察具体句式与特定语篇之间的关系。本章选取了存现句、判断句、处置句和被动句四种句式，其中存现句和判断句同事物说明语篇之间的关系密切，两类句式对前景的依存度高于对背景的依存度，对主干部分的依存度高于对引入和结尾部分的依存度，两类句式的语篇功能主要是描写。处置句和被动句同语篇之间的关系疏远，两类句式对背景的依存度略高于对前景的依存度，对主干部分的依存度略高于对引入部分和结尾部分的依存度，两类句式的语篇功能主要是叙述。

第七章为“结语”，本章归纳了本文的主要结论，指出了进一步研究的空间。

Based on the theories of discourse grammar, this dissertaion studies the discourse grammar of ShiWu(事物) expository discourse. The dissertation consists of seven chapters.

Chapter one is “Preface”. This chapter defines the object of the study, and cards the previous research achievements, and introduces the theoretical background, content, research method and corpus of the study.

Chapter two to chapter six are the main content of the dissertation. On the whole, this dissertation studies the discourse grammatical phenomena of ShiWu(事物) expository discourse from macro to micro and from abstract to concrete.

Chapter two is “the Discourse Features of ShiWu(事物) Expository Discourse”, which defines the discourse features of ShiWu(事物) expository discourse form five aspects, they are “Agent Orientaion”“Contingent Temporal Succession”“Objectivity”“Description” and “Substantiality”. The discourse features of ShiWu(事物) expository discourse are as follows, [- Agent Orientaion][- Contingent Temporal Succession][+ Objectivity][+ Description] [+ Substantiality]. 

Chapter three is “the Discourse Structure of ShiWu(事物) Expository Discourse”, which divides the structure of the ShiWu(事物) expository discourse into three part from the perspective of the whole discourse, which are introduction, body and ending. The body is the necessary part of the discourse, and the introduction and the ending are the optional parts of the discourse. The body part follows the instruction order, which can be divided into macro instruction order, meso instruction order and micro instruction order, each kind of description order includes spatial order, temporal order and logical order.

Chapter four is “the Representation of the Explanatory Object of the ShiWu(事物) Expository Discourse”, which studies the advancing of discourse from four aspects from the perspective of explanatory object. The four aspects are the explanatory object and title, the introduction of explanatory object, the advancing of explanatory object and the receding of explanatory object.

The explanatory object usually appears in the title of the discourse. When the explanatory object appears for the first time, it is often preceded by an introductory element. There are two types of the advancing of the explanatory object, the first type is the same explanatory object’s advancing, and the second type is the different explanatory objects’ advancing. In the first one type, the reference of the explanatory object shows the characteristics from complexity to simplicity, and in the second type, the explanatory object is usually introduced by the upper explanatory object in the object system. There are two types of receding of explanatory object, the first type is receding by means of explanatory object, and the second type is receding by means of things other than explanatory object.

Chapter five is “the ‘Foreground-Background’ and the ‘Transitivity’ of the ShiWu(事物) Expository Discourse”, which examines the characteristics of the foreground-background and transitivity of the ShiWu(事物) expository discourse from several perspectives, such as semantics, syntax and expression.

It is found that, the foreground of the discourse is embodied in [+ The Systematization of the Content], [+ The Consistency of the Subjects], [+ The Topicality of the Explanatory Object], [+ The Dependence on Description or Explanation], [+ Objectivity], [+ Spatiality], [+ State], [- Contingent Temporal Succession], and the background is embodied in [- The Systematization of the Content], [- The Consistency of The Subject], [- The Topicality of the Explanatory Object], [+/- the Dependence on Description or Explanation], [+/- Objectivity] [+/- Spatiality], [+/- State], [+/- Contingent Temporal Succession]. The expository discourse as a whole is characterized by low transitivity, the transitivity of the foreground is low, the transitivity of the background is not high.

Chapter six is “the Applicability of Different Sentence Patterns”，which examines the relevance between specific sentence patterns and the given discourse. It selects four sentence patterns: existential sentence, judgment sentence, disposal sentence and passive sentence.

It shows that the existential sentence and the judgment sentence are closely related to the ShiWu(事物) expository discourse. Those two types of sentence patterns are used more frequently in the foreground than in the background, in the body part than in the introduction and the ending part. The main discourse function of the two types of sentence patterns is description. As for disposal sentence and passive sentence, the relationship between the two types of sentences and the ShiWu(事物) expository discourse is alienated. The frequency of the two types of sentence patterns in the background is slightly higher than that in the foreground, the frequency of the body part is slightly higher than that in the introduction part and the ending part. The main discourse function of the two types of sentence patterns is narration.

Chapter seven is“Conclusion”, which summarizes the main conclusions of this paper and points out the space for further research.