【正文】 s of meaning. Since it is a mon framework, application designers can leverage the availability of mon RDF parsers and processing tools. The ability to exchange information between different applications means that the information may be made available to applications other than those for which it was originally created. RDF is based on the idea of identifying things using Web identifiers (called Uniform Resource Identifiers, or URIs), and describing resources in terms of simple properties and property values. This enables RDF to represent simple statements about resources as a graph of nodes and arcs representing the resources, and their properties and values. Note that this RDF/XML also contains URIs, as well as properties like mailbox and fullName (in an abbreviated form), and their respective values , and Eric Miller. Like HTML, this RDF/XML is machine processable and, using URIs, can link pieces of information across the Web. However, unlike conventional hypertext, RDF URIs can refer to any identifiable thing, including things that may not be directly retrievable on the Web (such as the person Eric Miller). The result is that in addition to describing such things as Web pages, RDF can also describe cars, businesses, people, news events, etc. In addition, RDF properties themselves have URIs, to precisely identify the relationships that exist between the linked items. This Primer is intended to provide an introduction to RDF and describe some existing RDF applications, to help information system designers and application developers understand the features of RDF and how to use them. In particular, the Primer is intended to answer such questions as: What does RDF look like? What information can RDF represent? How is RDF information created, accessed, and processed? How can existing information be bined with RDF? The Primer is a nonnormative document, which means that it does not provide a definitive specification of RDF. The examples and other explanatory material in the Primer are provided to help readers understand RDF, but they may not always provide definitive or fullyplete answers. In such cases, the relevant normative parts of the RDF specification should be consulted. To help in doing this, the Primer describes the roles these other documents play in the plete specification of RDF, and provides links pointing to the relevant parts of the normative specifications, at appropriate places in the discussion. It should also be noted that these RDF documents update and clarify previouslypublished RDF specifications, the Resource Description Framework (RDF) Model and Syntax Specification [RDFMS] and the Resource Description Framework (RDF) Schema Specification [RDFS]. As a result, there have been some changes in terminology, syntax, and concepts. This Primer reflects the newer set of RDF specifications given in the bulleted list of RDF documents cited above. Hence, readers familiar with the older specifications, and with earlier tutorial and introductory articles based on them, should be aware that there may be differences between the current specifications and those previous documents. The RDF Issue Tracking document [RDFISSUE] can be consulted for a list of issues raised concerning the previous RDF specifications, and their resolution in the current specifications. RDF is based on the idea that the things being described have properties which have values, and that resources can be described by making statements, similar to those above, that specify those properties and values. RDF uses a particular terminology for talking about the various parts of statements. Specifically, the part that identifies the thing the statement is about (the Web page in this example) is called the subject. The part that identifies the property or characteristic of the subject that the statement specifies (creator, creationdate, or language in these examples) is called the predicate, and the part that identifies the value of that property is called the object. So, taking the English statement 3. The RDF Model Since RDF uses URIrefs instead of words to name things in statements, RDF refers to a set of URIrefs (particularly a set intended for a specific purpose) as a vocabulary. Often, the URIrefs in such vocabularies are anized so that they can be represented as a set of QNames using a mon prefix. That is, a mon namespace URIref will be chosen for all terms in a vocabulary, typically a URIref under the control of whoever is defining the vocabulary. URIrefs that are contained in the vocabulary are formed by appending individual local names to the end of the mon URIref. This forms a set of URIrefs with a mon prefix. Using mon URI prefixes provides a convenient way to anize the URIrefs for a related set of terms. However, this is just a convention. The RDF model only recognizes full URIrefs。 6. 定義 RDF 詞匯 :RDF 輪廓 RDF 提供一個表達關(guān)于資源的簡單陳述的方法 ,使用命名了的特性和價值。如此的名稱時常是僅僅是簡單的特征直線，不過這不會總是這種情形。 RDF 應用軟件有時需要描述使用 RDF的其他 RDF陳述 ,舉例來說 ,記錄關(guān)于當陳述被創(chuàng)下的時候的信息 ,誰制造了他們 , 或其他的相似數(shù)據(jù) .(有時這被稱為 “起源” 數(shù)據(jù) ) 有時特性價值需要的是一個可擴展標示語言的碎片，或可能包含可擴展標示語言漲 價的本文。 時常有需要描述群體的事物 :例如 ,說共同創(chuàng)作了一本書被一些作家 ,或列出課程的學生 , 或列出一個里的軟件組件。 比較對一些更多縮寫了在 [RDF語法 ] 中被描述的方法 , 這種簡單的方式是提供真實的曲線圖結(jié)構(gòu)的最直接的表現(xiàn) , 而且特別地被推薦給申請在輸出 RDF/XML是被用于較進一步的 RDF處理。 使用這些工具 , 一個 RDF 曲線圖被依下列各項寫在 RDF/XML里 : ）。（因為讀者熟悉的的是 XML， RDF/XML是“很好地 形成” XML所必須的。同樣地，如它的物體和一個空白的節(jié)一份陳述能被寫和 rdf一起使用一種特性元素： nodeID歸于代替 rdf:資源屬性。一個空白的節(jié)點在 RDF/XML中被提到使用 nodeID 屬性 ,藉由如它的價值一個空白的節(jié)標識符 ,在資源的 URIref中會以別的方式出現(xiàn)。一個空白的節(jié)點標識符服務在特別的 RDF/XML里面識別一個空白的節(jié)點文件。這些全部在 [RDF語法 ]中被描述。舉例來說， 相同的資源同時與一些特性和價值一起描述是典型的。 所有的這些選項在 [RDF語法 ]中被描述 )。（物體節(jié)的 URIrefs可能有時恐怕最好被寫如屬性價值）文字的節(jié)（總是反對節(jié)）變成元素本文內(nèi)容或?qū)傩詢r值。 RDF/XML用基本概念來編碼一個 RDF圖表作為 XML的原理屬性，元素內(nèi)容和屬性值 URIrefs的述語（連同一些節(jié)點）被寫成 XML QNames,有表示 namespace URI的短前綴 ,連同一個表示一個合格域名的元素或?qū)傩缘木植棵忠黄?,如他們形成最初的節(jié)點或述語的