Another way of distribution is through intermediary service agencies or agents. More publishers choose this easy and labor-saving distribution method. The agent providing this service integrates many publications from different publishers into a unified interface and retrieval system. They often have great initiative and advantages in electronic layout design, technology update and application. Users usually apply directly to the agent for subscription and get the right to use e-magazines. The editing method of electronic layout is the most important feature that distinguishes electronic magazines from printed magazines, and it is also the place where electronic magazines have the greatest connection with computer network technology and are deeply influenced by it. Its significance has gone far beyond the page itself, and it involves a variety of expressions of content, the selection and establishment of links, and various services provided to readers. , and has become the soul of the magazine. In the late 1980s, electronic magazines (such as PACS Review) were usually typeset in ASCII format and distributed by e-mail. A few years later, e-magazines were typeset in many different electronic formats and distributed through WWW. For readers, the quality and distribution methods of e-magazines have been greatly improved. For editors and publishers, the ever-changing tools bring not only the creativity and flexibility of typesetting, but also the unimaginable plasticity and great potential of many printed editions. The remarkable features of e-magazine in layout editing are determined by the following factors.
(1) electronic document database
The core of electronic magazine is electronic literature database. The electronic documents in the database are marked with various marks, so that the documents can be easily retrieved and extracted from the database, and then "regenerated" and displayed in various ways according to different requirements. In contrast, the core of the printed version is the "same" copy. Once printed and bound, it is difficult to change its established appearance. From the perspective of storage methods, traditional printed magazines are kept all over the world, and they are damaged by the passage of time and repeated use in personal bookcases or library shelves. However, the database of e-magazines is distributed in a limited place or several places and used by subscribers through the network. Different readers can choose different presentation methods, and magazine editors can constantly modify and update documents as needed. The daily updating and maintenance of database and the processing of electronic documents are very important links in the distribution of electronic magazines.
(2) Multiple choices of electronic typesetting formats
As mentioned above, an electronic magazine is different from a printed magazine because it can be displayed in many ways. The taste of electronic magazines in layout is often expected to cater to people's habit of reading printed magazines. PDF format, PostScript format, ASCII format, TeX and DVI formats for displaying, downloading and printing mathematical symbols, and scanned images such as GIF or JEPG format all tried to display and print articles in the same or similar form as printed versions. Magazines with complex mathematical formulas and symbols, special characters and images tend to use these formats. Among them, the PDF format of Adobe Acrobat was all the rage. One of its advantages is that readers can not only "flip through" electronic magazines page by page while browsing printed magazines, but also print out articles with the same layout as printed magazines, thus binding them into magazines with the same layout as printed magazines. In 1997, PDF is the preferred format for publishers and related electronic publishing projects to convert traditional printed versions into electronic versions. However, the shortcomings of PDF are also obvious. First of all, PDF files are usually large and take a long time to download. Secondly, the same page element method as the printed version is completely displayed on a screen of the computer, and the reader must flip the screen up and down, or choose a smaller scale to display it, no matter which choice is not satisfactory. In addition, the most obvious defect of PDF format is that it does not provide hypertext links, so that readers can freely "navigate" between articles. Therefore, compared with the HTML format supporting hypertext links mentioned below, the PDF format is far from reflecting the true style of e-magazines. The practical use of PDF format is usually as a tool for readers to print articles they want to save on paper.
(3) the application of hypertext link
The editing style of electronic magazines is quite different from the familiar printing style. Traditional print magazines adopt linear expression. From the beginning to the end of a book or an article, you can sort L by page number at a glance. However, the best expression of electronic magazines is nonlinear. This nonlinear expression is realized by hypertext link. Electronic layout usually consists of short and compact small modules, and the contents of these modules can generally be displayed on one or two screens, which is in line with people's habit of browsing and reading. More importantly, the modules are connected by hypertext links, allowing forward, backward or jump conversion. In terms of file types, this hypertext link is not limited to the link between texts, but also can link other types of related materials, such as images, audio-visual images, three-dimensional animation and other multimedia objects. As far as content is concerned, hypertext links can be used to link to other related resources involved in the article, such as links to traditional index/abstract databases, links from article footnotes to related publications, and quotations from other articles after publication. With the various applications of hypertext links, the amount of information that electronic magazines can provide far exceeds the limit of an article and a magazine. The colorful and creative application of hypertext links by different magazines also makes each e-magazine have its own unique style. This is unmatched by traditional printed magazines. For these reasons, more electronic magazines directly choose HTML files that can support text, pictures and other links at the same time. There are also some publishers and electronic projects that seek both by providing HTML files that support links and image files that are easy to print (such as PDF files). Technically, the long-term maintenance of electronic magazines is an important direction different from printed magazines. Once a printed magazine is published, it cannot be modified, and the publisher loses control of the magazine. However, the online distribution mode of e-magazine, the design characteristics of database and the choice of file format allow it to continuously update and improve its content after publication. The ingenious application of this update makes electronic magazines have many new functions that print magazines can't achieve. For example, the aforementioned "retrospective index" (preface
Referencing) is an article index that refers to articles after the publication of magazines and articles. These new applications not only add color to e-magazines, but also bring a series of unsolved problems.
Who will maintain the periodical for a long time and undertake and fulfill the responsibility of providing services for readers? From the point of view of technical support and convenience, whether it is a library or a publishing house, publishing houses or agents should and naturally can undertake the responsibility of maintaining and providing back issues for a long time. But what must be considered is, once the publishing house or agent closes down or merges for various reasons, can the electronic magazine it once published continue to be available for readers to read online? From the point of view of library, one of its important traditional functions is to provide readers (including online readers) with back magazines. However, the long-term preservation of electronic magazines is more complicated than that of printed magazines. It involves not only the natural consumption and loss of medium, but also the frequent updating and elimination of technology. Due to the rapid development of computer and network technology, we can predict that the technology used in electronic magazines will be eliminated in a short time. If the library chooses to keep the back electronic magazines by itself, it must pay constant attention and investment in manpower, material resources and financial resources to ensure the long-term availability of back electronic magazines. Otherwise, the server can't connect, and the links in the HTML document are out of date or invalid, which will inevitably affect the retrieval and readability of e-magazines and the reputation of e-magazines. Therefore, the preservation and maintenance of back issues of e-magazines and providing long-term services for readers are a factor that libraries must consider when subscribing to e-magazines. From another point of view, the long-term maintenance and provision of e-magazines need the full cooperation of publishers and libraries to properly solve them. A problem related to the distribution and long-term preservation of electronic magazines is how to effectively save network communication resources when magazines are widely distributed. Mirroring is a common choice.
Mirroring is to set up mirror servers in several different geographical locations to provide several magazines for readers in different geographical locations. In this way, readers can use local copies and pay little or no network communication fees. First of all, a premise of using mirror image is that e-magazines are not updated due to time or technical needs, which is just in contradiction with the renewability of e-magazines. Secondly, the application of electronic magazines to links is also a difficult point in the maintenance of mirror servers. E-magazines usually contain not only internal links such as content reports and full-text articles, but also many external links, such as links to other e-magazines, databases of indexing/bibliographic service institutions, etc. Therefore, the maintenance of electronic magazines will actually involve many aspects outside the magazine itself. In addition, the compatibility of platforms and other application software used in different mirror locations and the time difference in different geographical locations will also bring problems to the mirror. One of the design ideas of the Tulip E-magazine project in the United States is to provide copies to nine libraries in the United States when it is published, so that each library can provide services to readers locally. This method is no problem when ASCII file format is used in the initial stage of project implementation without considering magazine update. But later, when we began to consider using the HTML file format based on SGML, the problem was exposed. In a word, it is a very complicated job to provide and maintain and update multiple copies in real time to mirrors scattered in various geographical locations through the network.