select distinct 
object_name(a.object_id) tabname
,c.name colname
from sys.partitions a
inner join sys.index_columns b
 on a.object_id=b.object_id and a.index_id=b.index_id
inner join sys.columns c
 on b.object_id=c.object_id and b.index_column_id=c.column_id
where a.object_id=object_id('[分区表表名]')