Papers collected by HowNet for one year can be found. According to relevant public information, once the master's degree thesis is included in China HowNet, it will be permanently stored in the database of China HowNet, which can be retrieved by registered users at any time. However, there are certain conditions for online search for master's thesis. You must purchase the database of China HowNet, otherwise you can only make a preliminary search, and you can't read and download the full text of the paper.