代码示例2：DCq编码实例
<?xml version=”1.0″?>
<!DOCTYPE rdf:RDF [
<!ENTITY rdfns 'http://www.w3.org/1999/02/22-rdf-syntax-ns#'>
<!ENTITY rdfsns 'http://www.w3.org/2000/01/rdf-schema#'>
<!ENTITY dcns 'http://purl.org/dc/elements/1.1/'>
<!ENTITY dctermsns 'http://purl.org/dc/terms/'>
<!ENTITY dctypens 'http://purl.org/dc/dcmitype/'>