In Chinese, at present, it is mainly China HowNet, as well as Wanfang and VIP. Baidu Academic can also give it a try at present. If you know the title of the paper and want to find an article, you can try it in Baidu Library.

For foreign literature, Google Academic is the first choice, followed by large databases, such as wos；; Or you can go directly to official website in Nature and Physics Review Express.

Other methods, you can refer to Zhihu.