Periodical is one of the important information resources in various literature carriers. It is an important information tool to understand the latest development and level of various disciplines, and 70% of the information needed by general researchers comes from periodicals. With the rapid development of computer, network and multimedia technology, a new periodical form-electronic periodical came into being and showed great vitality. The price of literature has been rising year after year, but the purchasing power of individuals and units is limited. Therefore, we should make full use of online information resources. I. Introduction to Electronic Journals The research on electronic journals began in the 1970s, and the online journals of 199 1 have begun to take shape. It developed rapidly after 1995. China's first online electronic periodical "National Journal" was born in 1995. From June 65438 to June 1996, with the opening of CNKI China Periodical Network, all 3,500 periodicals collected by China Academic Periodicals (CD-ROM Edition) were online, and there were tens of thousands of online electronic periodicals. Among them, The China Scholar developed from a weekly magazine when 1995 was founded to a weekly magazine after 1998 in September, and it is updated daily today, showing a strong development momentum. Electronic periodicals, also known as electronic magazines, refer to periodicals published in machine-readable form, and can also be stored in optical, magnetic and other media (such as optical disks and magnetic disks). ) and can be read, retrieved and printed through computers and communication networks. Although the development history of electronic periodicals is not long, it is only ten years. Compared with printed periodicals with paper carriers, electronic periodicals are favored by readers because of their short publishing cycle, large information storage capacity, strong timeliness, quick and convenient retrieval and multimedia function. Electronic journals can be divided into floppy disk journals, CD-ROM journals and online journals according to publishing carriers. Network electronic periodicals can be divided into two categories: one is pure network electronic periodicals, and the whole process of editing, publishing, ordering and reading is carried out on the network without mirror paper; The other is an electronic periodical that digitalizes paper periodicals and connects them to the Internet, that is, a parallel publication-printed edition and electronic edition are issued at the same time. At present, most electronic periodicals belong to this category, such as national newspaper index, copying newspaper materials, youth digest, story club and other professional or mass periodicals. Second, access to electronic journals Electronic journals are scattered on the Internet, developing rapidly, and new electronic journals appear every day. Therefore, users are currently facing a basic problem, that is, how to effectively grasp the information sources and quickly obtain the information they need (these free network resources are rich in content and huge in quantity, which are valuable assets that cannot be ignored. Many information institutions and organizations provide some free online databases to varying degrees. There are three access methods: 175 1. Through the website of authoritative information institutions (1) and the China periodical network of Tsinghua Tongfang's CNKI (China Knowledge Resource Database), we can retrieve the titles and titles of nearly 5,000 academic periodicals in China (CD-ROM version) since 1994. It covers mathematical science, chemical engineering, energy, industrial technology, agriculture, electronic technology and information science, medicine and health, literature, history and philosophy, economy, politics and law, education and social science. , updated synchronously with printed periodicals every month, providing different levels of literature information retrieval services from index, title, abstract to full text. Among them, the title and abstract data are provided free of charge, and the full-text data is provided paid. Readers can browse the full text, extract articles, download and print the full text as needed. (2) Search through the website of Wan Fang Data Resource Center. This is a large-scale comprehensive information resource system, which contains as many as 22.08 million massive database resources. Mainly based on scientific and technological information, covering economic, cultural, educational and other related information (most of them are core journals that enter the statistical sources of scientific and technological papers in China). It is an important window for you to learn about online Chinese periodicals. (3) Search China sci-tech periodical database, foreign sci-tech periodical database, VIP news full-text database, new product collection, etc. The database of Chinese sci-tech periodicals on this website contains 1989 periodicals published so far, including more than 8,000 periodicals in natural science, engineering technology, agriculture, medicine and health, economy, education and library and information, and the number is increasing at the rate of100000 per year. (4) Through the website search of China Renmin University's full-text database of photocopied newspapers and periodicals, we have collected more than 3,500 humanities and social sciences documents published in domestic newspapers and periodicals since 1995, and displayed all the original texts of more than 100 specialized publications listed in the printed newspapers and periodicals. Literature is divided into education, literature and history, economy and politics, and there are more than100000 kinds of existing literature records. (5) Shanghai Digital Library's national newspaper index database, relying on the national newspaper index, contains social science and technology literature resources since 1875. It is a super-large literature data center in China, with the characteristics of large amount of literature information, many retrieval points and fast retrieval speed.