thinkphp中想把数据库中取出的数据 和利用count统计出的数字合并到一个数组中

thinkphpphp数组

 Array(    [0] => Array        (            [paper_id] => 2            [student] => 小丸子            [subject] => 信息技术            [sj_title] => 信息考试            [paper_createtime] => 2015-10-14 13:39:08        )    [1] => Array        (            [paper_id] => 2            [student] => 小丸子            [subject] => 信息技术            [sj_title] => 信息考试            [paper_createtime] => 2015-10-14 13:39:08        ))数组bArray(    [0] => Array        (            [num] => 2        )     [2] => Array        (            [num] => 1        ))    想要的结果：     Array(    [0] => Array        (            [paper_id] => 2            [student] => 小丸子            [subject] => 信息技术            [sj_title] => 信息考试            [paper_createtime] => 2015-10-14 13:39:08                        [num] => 2        )    [1] => Array        (            [paper_id] => 2            [student] => 小丸子            [subject] => 信息技术            [sj_title] => 信息考试            [paper_createtime] => 2015-10-14 13:39:08                        [num] => 1        ))

试了数组合并array_merge_recursive 和array_merge貌似都不行，应该如何实现？