“泛时空化”指削弱或去除具体事物、事件或动作中的时间和空间属性的语法操作，是书面正式语体的特征之一，也是学术汉语的重要语体特征。通过自建语料库的考察，归纳了三类学术汉语泛时空化特征的语法表现。第一类是扩展基础语法形式的新用法，包括“和”构成的谓词性并列结构、“一种”的非计数用法以及“被”字句的中性化。第二类是句法移位改造基础语法为新形式，包括形式动词的范畴属性、介词结构的概括功能以及外壳名词的概念整合功能。第三类是名物化结构与语法隐喻，包括术语化、宾语转化为动词修饰语、陈述动词转化为指称动词、带特定词缀的中心词。研究表明，学术语体是知识渐进式构建的产物，通过有标记项、语法隐喻等手段集中表现泛时空化特征。学术语体并非纯粹意义上的“书面语”，而是书面语和口语连续体中正式程度较高的一种语体。本研究有利于丰富和深化语体语法理论，还能够为学术汉语的教学提供内容。

"Feature of weakening concrete space-time" refers to the grammatical operation that weakens or removes the temporal and spatial attributes of specific things, events or actions. It is one of the features of written formal style and an important stylistic feature of academic Chinese. Through the investigation of self-built corpus, this paper sums up the grammatical manifestations of three kinds of feature of weakening concrete space-time of academic Chinese. The first is the new uses that extend the basic grammatical forms, including the paratactic predication structure of "He", the non-counting use of "Yi Zhong" and the neutralization of Bei-construction. The second type is the transformation of basic grammar into a new form by syntactic shift, including the categorical attribute of formal verbs, the generalization function of preposition structure and the conceptual integration function of shell nouns. The third is nominalization and grammatical metaphor, including terminologization, object transformation into the modifier of verb, statement verb transformation into reference verb, and center word with specific affix. The research shows that academic register is the product of the progressive construction of knowledge. It manifests the feature of weakening concrete space-time through marked items and grammatical metaphors. Academic register is not a pure "written language", but a more formal register in the continuum of written and spoken language. This study is helpful to enrich and deepen the theory of stylistics grammar, and can also provide content for academic Chinese teaching.