Founded in June 1996 by Tsinghua University and Tsinghua Tongfang Holding Group, China National Knowledge Infrastructure (CNKI) project has been dedicated to promoting large-scale digitization of China knowledge resources and establishing a platform for global dissemination and value-added services for nearly two decades. CNKI is mainly engaged in integrating the digital publishing of Chinese academic and educational literature resources, providing specialized knowledge services, and undertaking technology development such as digital publishing, content resources management and value-added information services. CNKI has been dedicated to exploring and researching the pattern of China knowledge cultural industry through large-scale and intensified publication, giving birth to the comprehensive “China Integrated Knowledge Resources Database” with academic research findings at the core. With complete coverage of China journals, doctoral dissertations and master theses, newspapers, conference proceedings, yearbooks, reference books, encyclopedias, patents, standards, scientific and technological research findings, laws and regulations, “China Integrated Knowledge Resources Database” is the most comprehensive knowledge system that integrates 90% of China knowledge and information resources. CNKI products have been exported to over 1,300 institutions in 45 countries and regions, They have been essential tools for insititutes worldwide to carry out studies on China。
Navigation function helps narrow down your search range and provide quick access to information. All products have a common navigation method, namely subject navigation, also known as 10 series navigation; they also have navigation methods of their own based on different resource characteristics, such as journal navigation, degree-granting institution navigation , conference proceedings navigation and newspaper navigation.
（1）Click “select all” to select all navigation categories; click “clear” to clear up all categories selected (see figure 2);
（2）Click the option in front of the subject name to limit the search to one or more categories (see figure 3);
（3）The page merely shows series by default.Clickto reveal all subjects under one series, and clickagain to get sub-subjects；It also allows subjects search across different series. Click and the text of lower levels is hidden (see figure 4).
Journals can be navigated by the first letter (pinyin alphabet) of Journal Titles (A-Z), Subjects, Citation Index Databases, Publication Frequency, Journal Honors, Century Journals, China Core Journals, China University Selected Scientific Journals, Publication Locations and Sponsors (see figure 5).
Select “Journal Title, ISSN, CN” in the option menu and enter search terms in the box to search (see figure 7).
7 search methods are provided to meet the needs of the academic literature search: Quick Search, Basic Search, Professional Search, Scholar Search, Fund Search, Sentence Search, and Source Search.
The default search method is “Basic Search”.
Type in the search term in the searching bar and click the “Quick Search” button (see figure 8).
There are two parts under basic search: content search range and content features. The content search range is folded by default, and you can click the plus sign to unfold it and type in detailed search control conditions.
The content features search defaults to subject search, with two search words processed in Boolean Retrieval model. It allows cross-language search (Chinese & English search words, and related words) by default, which increases the recall ratio to a larger extent (see figure 9). You can also check “Online First” to search the articles whose full text are published online prior to their inclusion in a final print, which helps to quickly access the latest academic trends.
You can type in retrieval formulas based on retrieval grammar and logical operators in Professional Search which is specially designed for professional users who are apt to do complicated search (see figure 10).
By entering the author’s name and institution, you can get all the articles published by the author and related information such as cites and downloads. And you can have a full picture of the author’s research fields and findings based on the grouped search results (see figure 11).
You can find the funded articles by entering the fund title. And the grouped information will give you the whole picture of the research fields and subjects covered by a specific fund. You can also click button after the search box, select related funds and search the article (see figure 12).
Enter two search terms to get the articles containing them two in a sentence or in a paragraph (see figure 13).
Enter the journal information (name, ISSN number, CN number) to get articles included in the journal (see figure 14).
【Source database】Group search results according to seven defaulting databases: China Academic Journals Full-text Database, China Doctoral Dissertations Full-text Database, China Masters' Theses Full-text Database, China Proceedings of Conference Full-text Database, International Proceedings of Conference Full-text Database, China Core Newspapers Full-text Database, China Yearbooks Full-text Database.
【Subject】Group search results by more than 3,000 sub-subjects of 168 major subjects and help users refine results and find expected literature.
【Research Leve】Group articles into two categories— natural sciences and social sciences.
【Author】Help researchers track the publication status of some experts.
【Author Affiliation】Group search results by author affiliation and help users find valuable research information about major research institutions.
【Keywords】Show the knowledge system of the search results.
【Fund】Show the funds that supporting the articles.
【Publication Year】Group the search results by publication year.
Results are automatically sorted by relevance, and can be resorted by publication date, cites or downloads.
【Publication Date】Sorted by the publication date of articles.
【Relevance】Sorted by the relevance between search results and search words.
【Cites】Sorted by articles cites.
【Downloads】Sorted by article downloads.
Subscribed: This icon indicates this article has been subscribed, and the full-text can be downloaded.
Unsubscribed: This icon indicates this article has not been subscribed, and the full-text can’t be downloaded.
Not logged in yet: This icon indicates that you are not logged in, with only search and browse functions available.
Full-text unavailable: This icon indicates that this article is classified or hasn’t been authorized by publishing house, so its full-text download service hasn’t been activated.
The defaulting display style is list view, and it can be changed into detail view.
List view: displaying the title, author, journal title, publishing year/issue, articles cites, and downloads (see figure 19).
Detail view: displaying the title, author, journal title, keywords, abstract, downloads and publication time (see figure 20).
The defaulting records per page is 20, and it can be changed into 10 or 50 (see figure 21).
【Search history】In addition to “search” action, “grouped by” and “search in result” actions will both be saved in time order, so users can click “search history” to find previous search result (It only works in one login).
【Similar words】The system will recommend words similar to the search word. Click any word, and you will be automatically directed to the new page.
【Relevant words】The system will recommend words relevant to the search word, and help users to reconstruct more effective query. (see figure 22)
Click “Save” to export batched reference-format documents by one shot, at most 50 records (see figure 23).
And the reference can be customized to meet different needs (see figure 24).
A Journal Information, including journal title, sponsor, publication frequency, publication location, language and journal history, etc.
B Search in this journal: search within all contents of this journal or within specific years/issues. Search terms include subject, title, keywords, abstract, author, author affiliation, reference, full-text, fund and CLC Code.
C Year/Issue information: click a specific year to reveal all the issues published in that year, and click a specific issue to reveal the article list.
D Latest content: the article list of the latest issue. Click any title and get to its Knowledge Network Node page.(see figure 25)
Click the title of the article on the search result page and turn to its Knowledge Network Node page, which provides detailed and extended information of the article. These extended information reveals the knowledge networks woven by related concepts and facts, helping to discover, acquire and expand knowledge (see figure 26).
【Node document】Information includes: title, author, institution, abstract, keywords, fund, source, CLC code, cites, downloads, snapshot search of full text, and Knowledge Network Node download (see figure 27).
【Knowledge Network】of Current Document Includes: reference, sub-reference, citing documents, sub-cited documents, co-citing documents and co-cited documents.
【Reference】overall or partial reference to a book or thesis during academic research.
【Sub-reference】the reference of this article’s reference sources, further reflecting the research background and basis.
【Citing Documents】documents that cite this article.
【Sub-cited Documents】documents that cite the citing documents of this article, further reflecting the development and evaluation of the research.
【Co-citing Documents】documents that share the same references and research content with this article.
【Co-cited Documents】documents cited as reference together with this article. If document A and B are both cited as references by document C, then document A and B are Co-cited Documents.
In addition, Knowledge Network Node page reveals other relevant documents, including similar documents, co-concerned documents, documents of related authors, documents of related institutions, and subjects navigation by CLC.
The system provides two download formats: A. Clickbeside the title to download PDF format on search result page; B. Click、，to download CAJ and PDF format respectively on Knowledge Network Node page.
Please download and install CAJViewer on the home page of the platform if you choose CAJ format.
And we strongly recommend you to choose CAJ download or PDF download by chapter, since the large PDF file will easily cause 504 error.