Nginx Reverse Proxy Dynamic PDF URL and Online Preview

location ~ /wlwxb/(?<aid>[0-9]+)/paper.pdf {
resolver 114.114.114.114;
proxy_pass http://www.wlwxb.cn/CN/article/downloadArticleFile.do?attachType=PDF&id=$aid;
proxy_hide_header Content-Type;
proxy_hide_header Content-Disposition;
add_header Content-Type application/pdf;
}