1. We need to open CAJ first, and find out the reason why the directory column disappears. 2. If it is deleted by mistake, you can reopen it in the view. 3. If it is auto-hiding, you can cancel auto-hiding.

CAJ(ChinaAcademicJournals) refers to the full-text database of academic journals in China. CAJ is also a file format in the full-text database of China academic journals. CAJ stands for China Academic Journal Full-text Database (China Academic Journal); CAJ is also a file format in the full-text database of China academic journals. You can read it with CAJ full-text browser. China Academic Journals Full-text Database is the largest continuously and dynamically updated China Journals Full-text Database in the world. Accumulated 8 million full-text documents, more than150,000 titles, divided into nine albums and 126 special literature databases. Its knowledge source is the full text of 6 100 core journals and professional journals published publicly in China. The data integrity of 6 100 full-text journals reached 98%. CAJ full-text browser is a special full-text format reader for China Journal Network. The reader is a series product of CD National Engineering Research Center and Tsinghua Tongfangzhi Network (Beijing) Technology Co., Ltd., and supports CAJ, NH, KDH and PDF files of China periodical network. You can read the original text of China Journal Network online or download the full text of China Journal Network to your local hard disk.