应该是字符集的问题,参考:
http://www.dbonline.cn/source/oracle/20040207/STR_Influence%20Character%20Question(1).html
http://www.dbonline.cn/source/oracle/20040207/STR_Influence%20Character%20Question(2).html
http://www.dbonline.cn/source/oracle/20040207/STR_Influence%20Character%20Question(1).html
http://www.dbonline.cn/source/oracle/20040207/STR_Influence%20Character%20Question(2).html
select * from sys.nls_database_parameters t