【導(dǎo)讀】有上百種，尚未形成公認(rèn)的定義。普遍性和客觀性；主觀性；依附性；可傳遞性；獨立性；時效性；消除不確定性功能；按對象劃分；自然信息、生物信息、機(jī)器信息和社會信息。按性質(zhì)劃分；語法信息、語義信息和語用信息。按利用者的角度和過程劃分；實在信息、先驗信息和實得信息。按內(nèi)容劃分；經(jīng)濟(jì)信息、科技信息、政治信息、文化信息、等等…按作用劃分；有用信息、無用信息和干擾信息?；⒋罅糠e累起來的有用信息的集合。信息生產(chǎn)者、信息技術(shù)等信息活動要素的集合。他人利用，且易于消失，是一種有限再生的信息資源。一次信息資源、二次信息資源和三次信息資源。通常為情報研究的成果。連續(xù)出版物；期刊、報紙、年度出版物。數(shù)量巨大、增長迅速。有明確的收錄范圍；

　　

【正文】 ClN ? Exact Structure Search ? Substructure Search ? CAS RN: 17155316 ? Melting Point, Boiling Point ? RTECS OPharmaprojects ? Pharmaprojects is the leading source of global business intelligence on drugs in Ramp。D and provides users with a prehensive view of product development ? Pharmaprojects monitors every significant new drug currently under development, tracking all new drug candidates under active international Ramp。D approximately 6,000 at any one time. Pharmaprojects ? Pharmaprojects contains details on over 26,000 new drug candidates which have been investigated since 1980, including those currently in research and those whose development has been discontinued. How can help your business ? Track who is developing what, where, when, how and for what! ? Analyze your market of interest using any bination of 60 search criteria ? Monitor your close petitors ? Discover licensing opportunities and comarketing partners ? Identify early leads and search for similar chemical structures Database Content ? more than 26,000 developmental drugs and pharmaceutical formulations investigated since 1980 ? over 6,000 of these are undergoing Active development ? 20,000 or so are classified by Pharmaprojects either as Ceased or Fully Launched. ? presented in the form of Product Profiles, anized under 10 main headings Searching Example ?Tree Searh ?Browse Search ?Structure Searh CAS Number: 185243690 Drug Name: Tamiflu, Panzem, ruprintrivir, caffeine Company: ASTRA, Pfizer Originator: China Market Rating: China+over US$10000M Novelty Rating: Leading Compound OOThe Merck Index on CDROM version 13:2 ?More than 10,000 monographs ?Covering natural products, environmentally important pounds, biological and agricultural pounds, mercial and labortory chemicals ?To provide text and structure searching Searching Example ?Compound Searh Tamiflu, AG1749 ?Name Reaction DielsAlder Reaction HuangMinlon Reaction Haworth Phenanthrene Synthesis ?Tables Science of Synthesis 簡稱 SoS 1. It is a highly anized and authoritative treatise on anic synthetic methods. 2. Extensive review chapters are written by recognized experts, and contain full experimental procedures and background information. 3. Its goal is to provide a direct path through the mass of primary literature to the pertinent data on a prehensive range of anic reactions. 4. Each volume covers a specific class of pound. Volumes are anized into Categories, which are in turn broken down into narrower specialty volumes. 5. Thieme began publication of SoS in 2020, and it is planned to occupy 49 volumes by its pletion. About six new volumes are published each year. How does it relate to SciFinder Scholar and Beilstein (MDL) Crossfire? 1. Science of Synthesis is a selfcontained reference work, analogous to a treatise or encyclopedia, that is highly proscribed and planned and written by experts. By contrast, Chemical Abstracts (via SciFinder Scholar) is an openended bibliographic index to the entire chemical literature, broadly defined. Beilstein (via MDL Crossfire) is a database of anic pounds and reactions derived from a selected subset of the chemical journal literature. Neither SciFinder or Beilstein contains authored, textual descriptions of synthetic procedures, though they provide plentiful links to the primary literature on these topics. How does it relate to SciFinder Scholar and Beilstein (MDL) Crossfire? 2. Science of Synthesis plements these two important tools and should be used in conjunction with them. Unlike SciFinder or Beilstein, it is browsable by a hierarchical table of contents as well as searchable by structure and keyword. A chemist looking for background information on the present knowledge of a type of synthetic method or class of pounds would want to start in SoS and follow up with searches for structures/reactions and/or keywords in SciFinder Scholar, and for structures/reactions in Beilstein. Science of Synthesis chapters provide numerous references to the journal literature, but these are selective, not prehensive. Methoden der Organischen Chemie (HoubenWeyl) ? Science of Synthesis的前身 ? Methoden der Organischen Chemie (Methods of Organic Chemistry, often called HoubenWeyl) is a standard reference work for chemists engaged in anic synthesis. In volumes on pound classes, including all Supplemental volumes, preparative methods are treated prehensively and critically. Tables of examples pare the most important methods and show their scope. Detailed experimental procedures are given for the best methods. The reactivity and further reactions of each pound class are also presented. The extensive use of formula schemes help make the Germanlanguage volumes more readily understandable to nonGerman readers. ? 分類組織架構(gòu) Methoden der Organischen Chemie (HoubenWeyl) ? The 4th Edition began publication in 1952. The base set of 16 volumes (in 70 parts) was pleted in 1987, and covers the full range of anic synthetic topics. ? In 1982 a Supplemental series began (the Evolumes), which gives further and updated information on topics covered in the base set, as well as new areas not covered earlier. The Eseries is scheduled for pletion in 1999。 volumes appear irregularly and out of order. ? All volumes are in German until 1990, after which they were published in English. HoubenWeyl is a textual source, and has no online or electronic equivalent. Why should you use HoubenWeyl? 1. HW offers a valuable and unique addition to standard synthetic reference sources. Unlike the Beilstein handbook or database, extensive experimental detail is provided for products and reactions。 resul