《文讯》是媒介型文学史,是编年体与纪传体相结合的原生态、遗留态、评价态三合一的台湾文学史,被专家称为"台湾文学的简史":其一,它办刊的历史,再现和浓缩当代台湾文学史:即由威权时代的文宣工作,进入解严前后怀柔的"文化领导权"实践,最后转为民营进入文学多元发展时代,它是台湾文坛的"镜像";其二,《文讯》透过史料整理,保存文学历史,对作家的报道,出版、艺文动态的记录,对文学的研究,体现"写史"的企图,它是"遗留态"的历史;其三,文学期刊与文学历史是"同型对应"、"同源互文"和"异构同质"关系。《文讯》从文类、断代、区域、作家、题材等面向透过专题策划,呈现当代台湾文学众声喧哗、合力书写的历史。
X-ray diffraction and optical microscopy were used to analyze the precipitation kinetics and microstructure evolution of δ-phase in GH4169 alloy at 900℃ and 930℃.The results indicate that the sites and modes of δ-phase's nucleation were related to aging temperature.At 900℃,δ-phase mainly precipitated in the grain and twin grain boundaries,intragranular δ-phase was found to be derived from the mestastable γ″ phase in both grain and grain boundaries.At 930℃,δ-phase precipitated in the grain and twin grain boundaries.Also,δ-phase was found to precipitate from the γ matrix.With the increase of the aging time,delta phase grew into grains,and finally transformed into widmanstatten δ-phase.At a given aging temperature,the relationship between the precipitation content of δ-phase and aging time follows Avrami equation.