在model/article.php添加如下函数，你在app/explore/main.php调用这个函数。剩下的你应该知道怎么在侧边栏显示这个返回值了。

 public function get_hot_comments($day, $limit)
	{
        if ($comments = $this->fetch_all('article_comments', 'add_time > ' . (time() - (60 * 60 * 24 * $day)), 'votes DESC', $limit, 0))
		{
			foreach ($comments AS $key => $val)
			{
				$comment_uids[$val['uid']] = $val['uid'];
                $article_ids[$val['article_id']] = $val['article_id'];
			}

			if ($comment_uids)
			{
				$comment_user_infos = $this->model('account')->get_user_info_by_uids($comment_uids);
			}
            
            if ($article_ids)
			{
				$article_infos = $this->model('article')->get_article_info_by_ids($article_ids);
			}


			foreach ($comments AS $key => $val)
			{
				  $s_comments[$key]['message'] = $comments[$key]['message'];
                  $s_comments[$key]['user_name'] = $comment_user_infos[$val['uid']]['user_name'];
                  $s_comments[$key]['uid'] = $comment_user_infos[$val['uid']]['uid'];
                  $s_comments[$key]['url_token'] = $comment_user_infos[$val['uid']]['url_token'];
                  $s_comments[$key]['title'] = $article_infos[$val['article_id']]['title'];
                  $s_comments[$key]['article_id'] = $article_infos[$val['article_id']]['id'];
			}
		}
        
        return $s_comments;
    
    }