三、期刊期刊一般是指以固定的名称、定期或不定期地连续出版的一种出版物,每年至少出版一期。定期期刊大致分属于两种类型:一类技术性较强,属摄影科学类,这类期刊的主要内容是研究论文,其次是综沦、书评、学会活动等,有的也附有文摘,这类期刊对从事感光材料科技工作的同志参考价值较 Periodicals Periodicals generally refer to a publication that is published on a regular or irregular basis, with a fixed name, at least once a year. There are two types of periodical general roughly divided into: a class of highly technical, is a science of photography, the main content of such journals is research papers, followed by comprehensive reduction, book reviews, learning activities, and some also attach abstracts, such Journals engaged in photographic materials science and technology comrades reference value