$data = file_get_contents('xml-file.xml');
$doc = new DOMDocument();
@$doc->loadHTML($data);
$elements = $doc->getElementsByTagName('item');
$url = $elements->item(0)->getElementsByTagName('feedburner:origLink')->item(0)->nodeValue;
另一方面,title,guid,description工作,不明白为什么
$title = $elements->item(0)->getElementsByTagName('title')->item(0)->nodeValue;