PHP+JSON génère des caractères chinois

<?php 
function Notice(){
    include &#39;./include/conn.php&#39;;  //数据库链接文件
    $sql_notice = 
mysql_query
(&#39;SELECT * FROM gg_notice where enable = "1" limit 0,10&#39;);
    $notice = 
mysql_fetch_array
($sql_notice, MYSQL_ASSOC);
    $str = json_encode($notice);
    //linux
    return preg_replace("#\\\u([0-9a-f]{4})#ie", "iconv(&#39;UCS-2BE&#39;, &#39;UTF-8&#39;, pack(&#39;H4&#39;, &#39;\\1&#39;))", $str);
    //windows
    //return preg_replace("#\\\u([0-9a-f]{4})#ie", "iconv(&#39;UCS-2LE&#39;, &#39;UTF-8&#39;, pack(&#39;H4&#39;, &#39;\\1&#39;))", $str);
    
}
?>

 <?php
/*** json 生成,分析 支持中文
 */
class Json_Helper {
    /**
     * 生成json
     */
    public static function encode($str){
        $json = json_encode($str);
        //linux
        return preg_replace("#\\\u([0-9a-f]{4})#ie", "iconv(&#39;UCS-2BE&#39;, &#39;UTF-8&#39;, pack(&#39;H4&#39;, &#39;\\1&#39;))", $json);
        //windows
        //return preg_replace("#\\\u([0-9a-f]{4})#ie", "iconv(&#39;UCS-2LE&#39;, &#39;UTF-8&#39;, pack(&#39;H4&#39;, &#39;\\1&#39;))", $json);
    }
        /**
     * 分析json
     */
    public static function decode($str) {
        return json_decode($str);
    }
}
?>