Plsql query out the problem of Chinese garbled

This problem must be caused by a different character set on the sever character set and the following method:
1. Query the Oracle server-side character set. Open SQL window to enter the character set for the SQL query service side below.
Select Userenv (' language ') from dual;
2, My Computer environment variable interface, in the system variable added:
Variable name: Nls_lang
Variable value: Simplified Chinese_china. Zhs16gbk
The value of the variable is consistent with the server query.

Plsql query out the problem of Chinese garbled