我想知道这是什么数据类型，所以我可以在 PHP 中对其进行解码：
{s:31:"xperience_achievements_you_have";s:20:"You have %1$s points";s:26:"xperience_award_drawnin_of";s:69:"<b>%1$s</b> drawn-in of <a href="member.php?u=%2$s">%3$s</a> on %4$s.";s:26:"xperience_award_issued_for";s:68:"<b>%1$s</b> issued for <a href="member.php?u=%2$s">%3$s</a> on %4$s.";s:35:"xperience_award_issued_for_multiple";s:42:"<b>%1$s</b> issued for more than one user.";s:27:"xperience_award_issued_none";s:36:"<b>%1$s</b> has not yet been issued.";s:20:"xperience_awards_log";s:25:"Activity on issued Awards";s:28:"xperience_awards_used_fields";s:12:"Fields used:";s:17:"xperience_details";s:12:"Show details";s:14:"xperience_earn";s:11:"Earn Points";s:21:"xperience_earn_factor";s:6:"Factor";s:20:"xperience_earn_yours";s:5:"Yours";s:20:"xperience_gap_choose";s:16:"Give Away Points";s:27:"xperience_gap_choose_amount";s:66:"Enter the amount of points. They must be below the amount you have";s:26:"xperience_gap_choose_field";s:63:"Choose the category from where the points are being substracted";s:25:"xperience_gap_choose_user";s:49:"Type the name of the user who will receive points";s:23:"xperience_gap_give_away";s:9:"Give Away";s:18:"xperience_gap_more";s:31:"<a href="%1$s">Show more...</a>";s:18:"xperience_gap_text";s:156:"This is an automated message to inform you of a transfer to your Experience points.\r\n \r\n User [URL=%1$s]%2$s[/URL] has give away points to you:\r\n %3$s";s:19:"xperience_gap_title";s:46:"Experience: Notification of a Points Give Away";s:22:"xperience_gap_you_have";s:8:"You have";s:16:"xperience_groups";s:13:"Group Ranking";s:22:"xperience_groups_empty";s:17:"No Social Groups.";s:20:"xperience_groups_max";s:10:"Max Points";s:20:"xperience_groups_min";s:10:"Min Points";s:27:"xperience_groups_minmembers";s:96:"Only public and moderated Social Groups with at least %1$s members are included in this ranking.";s:17:"xperience_insight";s:18:"Insight Experience";s:26:"xperience_insight_featured";s:8:"Featured";s:20:"xperience_insight_sg";s:10:"Best Group";s:23:"xperience_insight_tipps";s:26:"Hints on collecting points";s:28:"xperience_insight_tipps_desc";s:77:"With Experience you can see how you progress compared to the whole Community.";s:28:"xperience_insight_tipps_earn";s:105:"Use the <a href="xperience.php?go=earn">Earn Points</a> feature to learn how you can collect points.<br/>";s:35:"xperience_insight_your_achievements";s:17:"Your Achievements";s:29:"xperience_insight_your_awards";s:11:"Your Awards";s:35:"xperience_most_achieved_achievement";s:25:"Most achieved Achievement";s:27:"xperience_most_active_user7";s:27:"This Week: Most Active User";s:36:"xperience_most_exclusive_achievement";s:26:"Most exclusive Achievement";s:25:"xperience_no_achievements";s:30:"No Achievements are available.";s:19:"xperience_no_awards";s:23:"No Awards are assigned.";s:23:"xperience_no_promotions";s:28:"No Users have been promoted.";s:28:"xperience_promotion_benefits";s:41:"Benefits you can get with this usergroup:";s:37:"xperience_promotion_benefits_assigned";s:21:"Assigned Permissions:";s:36:"xperience_promotion_benefits_revoked";s:20:"Revoked Permissions:";s:32:"xperience_promotion_benefits_set";s:47:"<i>%1$s</i> set from <b>%2$s</b> to <b>%3$s</b>";s:33:"xperience_promotion_benefits_sets";s:22:"Additional allowances:";s:27:"xperience_promotion_ingroup";s:21:"You are in this group";s:25:"xperience_promotion_jumps";s:59:"Promotions are possible to these usergroups and conditions:";s:30:"xperience_promotion_notingroup";s:32:"You are <i>not</i> in this group";s:25:"xperience_promotion_users";s:37:"%1$s Users promoted to this Usergroup";s:19:"xperience_recent_aa";s:41:"Recently assigned Awards and Achievements";s:25:"xperience_recent_activity";s:15:"Recent Activity";s:15:"xperience_stats";s:10:"Statistics";}
它看起来像某种 JSON，但 json_decode 返回一个空字符串。提前致谢。