Modern literature consists of four elements: literature, literature carrier, symbol system and recording method.

Literature retrieval type

1) according to the form of test results: literature retrieval, full-text retrieval and citation retrieval.

2) Retrieval objects: literature retrieval, data retrieval and fact retrieval.

3) Through search: manual search and computer search.

4. Physical characteristics of documents (natural person status): title, author, source, volume, page, year, month and type language. Characteristics of literary content (human identity): subject words, classification numbers, class names and abstracts. It refers to the subject and core elements of literature.

5. Types of document retrieval system: According to the processing degree of document extracts, it can be divided into catalog-based retrieval system, abstract, catalog and full-text retrieval system.

6. File type information

1) Forms of document information: text, video, audio and numbers.

2) Document information release types: books, periodicals, government publications, technical reports, patent documents, conference papers, dissertations, standard documents, product samples, manuals and technical documents. Including books, periodicals, literature, literature and other majors.

3): Information carriers in print, microfilm, audio-visual and electronic forms.

The degree of document information processing: one document, two documents, documents and zero documents.

Literature: published books, periodical papers, technical reports, conference papers, dissertations and invention patents.

Second-hand literature catalogue, abstract, index Document information retrieval tools.

Three documents: divided into abstract categories (dynamic overview, topic summary, function description, progress report) and reference tools categories (manuals, yearbooks, complete works, dictionaries, encyclopedias, tour guides), and document retrieval function.

Zero literature: informal publications, unpublished and social, such as bills of exchange, personal notes, meeting minutes, unpublished celebrity notes, oral discussions, etc.

7. This kind of retrieval language

1), use the control according to the provisions of this article:

Normative language (control language, artificial language): Normative words or search title symbols are manually controlled. Such as unit word MESH, title words

Normative language (uncontrolled language, natural language) is the key word.

2) The features expressed in information retrieval language can be divided into

Description of language features in literary content: classification language, code language, theme, language (unit language, title, keyword (standard language) thesaurus)

The language that describes the external characteristics of literature: title, title, title, author, group author, citation, code/serial number.

Chinese biomedical literature database

1, according to the medical thesaurus (MESH), what does Chinese medicine mean? China Library Classification, Medical Professional Classification, Subject Indexing and Classified Indexing.

Database > document > record > field.

3. Default domain name: Chinese title, abstract, author, keyword, keyword and title.

Wildcard words: word wildcards (? ) Any (word) wildcard (%)

5. Intelligent search: only "default domain" and unsupported logical phrase retrieval are supported.

6. Source: magazine name+year; Quantity, period, first

7, keyword search-surgical treatment of diseases:

), keyword disease+"surgery" (vice)

2), surgical disease name+drug therapy+"method" (deputy)

3)# 1 +#2

-drugs for treating diseases: BR /> 1),

2) Drug+"therapeutic use"

3), 1 +2

After selecting a topic to visit, click "Topic Search" to search. After selecting a search category, press Search by Category.

1, PubMed database is a global biomedical literature database based on the Internet. Biomedical

2, including MEDLINE, which consists of three parts of references provided by processcitations publishers, and is identified by the temporary paper index forMEDLINE. In the process of medical identification, citation medicine provided by publishers is used as symbols provided by publishers.

3. Basic fields

China part code English part code English abbreviation title TI

Abstract AB

Author ou

Affiliate advertisements are posted on

Title -JN segment code

Publication year PY

Language LA

All fields, all fields, all.

The first 1AU

Rasto is in charge.

The title of the full name of MH periodical TA

Keywords article number TW/KW

3. Truncation operator: "*" means 0 or more characters, followed by CNKI, CBM%%.

4. Automatically convert the matching search order: network vocabulary, journal name list, phrase list index and logical operator. If you can't find four tables, let's talk about automatically dividing phrases, words or phrases into units, and repeat the above process respectively, searching and each word.

5. When searching for the logical relationship between phrases, pay attention to adding "or the logic of splitting it into individual words or phrases" and "connection".

6. AND, NOT or must be capitalized, and the name of the field can be added to the search term after "TI/AU".

& gt and > or

7. Search: the abbreviation of the author's surname in the space. If you only use name retrieval, you must add [AU] to the author field.

Title retrieval: If there are special symbols in the title, delete the title and abbreviation entered by the special symbols.

9. Topic access is limited to the main topic of the subject words. Weighted retrieval improves the accuracy.

Medical subject words that do not include words below the grid level are not expanded.

10 citation matching: a medical tool-single citation matching

Periodical retrieval: more resources-in NCBI database.

China National Knowledge Infrastructure Project

1, China Journal of Academic Journals (CJFD) is a sub-project of China HowNet source database construction, and it is the largest academic journal with dynamic update and consultation in the world at present.

2. The subject field is used as the default title and keyword to summarize the three integrations.

3. Periodical navigation function

For citation, please refer to: References.

: (SD)

1 is recognized by the industry as a high-quality academic journal (1823).

Need to add "or {}, when searching words or phrases, or taking words as a unit, carry out logical (and) search.

3. Journal impact factor or ISSN number: click on the cover of the magazine, "About this journal" impact factor: impact factor.

4 operatOR priorities: or, W/N, PRE/N, AND and NOT.

5. W/N: If the time interval between two times does not exceed N, this order is not fixed, and the word order of PRE/N is fixed. Two adjacent symbols, such as influenza W/3 drugs, cannot be used at the same time.

6 search: first name+abbreviation of full name or surname.

Fields can appear with different names, and author specificauthor is required.

8. Second search: search in the results. Limit: limit or exceed the selected range: exclude

9,

10, the latest top 25 articles jump directly to results, references and references.

1 1 search expression: the item found at the top of the page, expression

12 word wildcard (? )

China Sci-tech Periodical Database [

1, classified according to Library Classification of China (1989).

2 Default field: nomination or keyword

Synonym retrieval is advanced or traditional retrieval, but only title, keyword, title or keyword search field can be used, but the key step can be to write traditional retrieval expressions.

4. Operator "*" means sum, search result, "+"means or, added result, "-"means no, delete.

Knowledge is the essential content of literature, and the carrier is the external form and record of literature.

Literature retrieval with extensive knowledge and carriers is essentially a retrieval system, including file storage and literature retrieval.

Content: books and periodicals

Remember to evaluate the accuracy and timeliness of the document retrieval system, the perfection of the index system and the in-depth information index.

The accuracy and index depth of recall information reflect the characteristics of detailed description. Index degree is an important factor to determine the quality of related information retrieval system and detection.

Recall rate (R)=/ information content of retrieval tools

Accuracy (P)= relevant information detected/

Grammatical equivalence, subordination and correlation between total search title and search language detection

Search basic common law, backtracking method, circulation method and browsing method.

The basic steps of document retrieval include analyzing problems, defining retrieval requirements, selecting retrieval tools and methods, selecting retrieval marks and methods, processing retrieval results and obtaining original documents.

Symbol system of literary painting, characters, formulas, charts, codes, audio, video and electromagnetic information.

Comprehensive search engine, topic search engine, search engine

independence

Confidentiality, timeliness and transferability of information

Literature belongs to the solid carrier of savings.

CBM Data Index Title CBM Database About the latest edition of medical subject vocabulary (MESH vocabulary) According to the medical information published by the National Library of Medicine of the United States, the Institute of Chinese Medicine of China Academy of Fine Arts, the subject index of China Dictionary of Traditional Chinese Medicine, and the classification and classification of China Library Classification,

Structure of CBM Database and Interruption of System Operator

(2) System operator

Field: a field that records the composition of data items and reflects the specific characteristics of documents. Name (TI), author (au), address (ad), source (so), subject word (purpose), keyword (KW), characteristic word (TG), publication year (PY), language? (pull) and so on.

Records constitute the basic unit of database information. Each record describes the original information characteristics of appearance and content, and is usually recorded by multiple data items. Literature database records usually represent literature.

File: Yes, part of the record in the database. Many large databases usually contain hundreds of thousands of records for users to retrieve, and are usually divided into several files.

Title Keywords Abstract Source Publication Year

( 1)

CBM database records, including a database structure, have more than 30 searchable data items.

Abstract advertising address (author address)

AU author CN domestic code (domestic periodical code)

FS MH network of feature words

ISSN (International Journal Code) VI was published in 2005.

& gtPT literature types; 1。 Boolean logic operators (AND)

B. logical or

C. Logical "no"

Third, CBM database search operator

(2) first-order system operators

Boolean logic operator () > NOT> and> or,

2。 Wildcard: (1) words are wildcards, not characters. Portal vein and portal vein can detect portal vein pulsation.

Note: It must be half angle.

(2) Any wildcard%: Replace any number of characters. For example, hepatitis% vaccine can be detected: hepatitis vaccine, hepatitis virus gene vaccine, live attenuated hepatitis A vaccine and inactivated hepatitis A vaccine.

Force character/phrase search for characters "

If the search term is used as a phrase or contains special symbols "-"and "("in English, such as "1, 25-(OH)2D3".

CBM retrieval method

1, basic retrieval, subject retrieval search category, periodical retrieval 5, retrieval 6, restricted retrieval

1, basic search

Disadvantages: the retrieval error rate, accuracy rate and recall rate are not high.

2. Subject retrieval

Subject words are also called thesaurus (descriptors).

In the process of strict standardization, it can represent the theme of literature and the essence of technical terms.

Standardize different expressions and compulsory authority, and use one word to represent pronouns. Netted vocabulary, Chinese thesaurus

Subject retrieval: Literature content retrieval with the concept of subject is conducive to recovery and accuracy.

Based on advantages:

Conducive to the integrity and accuracy of inspection.

Expand or narrow the search scope (expand and expand weighted and unweighted)

The concept of ownership change and the limited literature in various aspects

(Groups with one or more subheadings)

Disadvantages:

It is difficult for non-professionals to master the indexing and retrieval of subject words.

Retrieval category: refers to the collection of subject or professional documents and national retrieval methods. If the subject of comprehensive document collection and accumulation does not know the classification system of literature disciplines, from classification refers to retrieval.

Search for the name of the Convention on Civil Liability for Oil Pollution Damage and the Classification Table of China Library Classification and Certification Science Specialty.

recover

You can search all the documents published by authors contained in the database, if the "first author" option is commemorated in the search results of the first document at the same time. & ltBR/6, retrieval only.

Limited search: integrating eligible literary works of different ages and types. Study a dialog box that is easy to retrieve.

5 Search the results and save them.

Results: A * * * has three formats:

System default description format: title, author, unit and source.

Format: title, author, abstract, source, keywords, keywords, function words.

Format: Based on the summary format, the scope has been increased, including all fields in the public sector.