因以下原因：
一、資源或業(yè)務(wù)僅限中山大學教職員和學生訪問（請在校園網(wǎng)內(nèi)或通過VPN隧道訪問），或
二、資源或業(yè)務(wù)不在服務(wù)時段（請在服務(wù)時段訪問）。
1. The web page that you are trying to access is ONLY provided for students,faculty and staff of Sun Yat-sen University.
2. The website can ONLY be accessed during restricted hours.