oracle数据库字符集编码乱码问题

connect system as sysdba ;  
shutdown immediate ;  
startup mount ;  
alter system enable restricted session ;   
alter system set JOB_QUEUE_PROCESSES=0;   
alter system set AQ_TM_PROCESSES=0;   
alter database open ;   
alter database character set internal_use ZHS16GBK ;   
shutdown immediate ;  
startup ;