$re = '/([^()]+)\(([^()]*)\)/m';
$str = 'ABC1.1(1) 拆分为ABC1.1和1 两部分
%DEF2.1(3) 拆分为%DEF2.1和3 两部分
@ I/O GHI3.3(5) 拆分为@ I/O GHI3.3 和5 两部分
ABC1.1(1)
%DEF2.1(3)
@ I/O GHI3.3(5) ';
$subst = "$1 $2";
$result = preg_replace($re, $subst, $str);
echo "The result of the substitution is ".$result;
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php