But I'm still confused because we often read "The Chinese is a peace-loving people." So could you tell me why it's "To us Chinese" instead of "To us the Chinese" in the base sentence? Thanks.
When a Chinese is asked the question, "What nationality do you belong to?" The person will reply, "I am a Chinese" Here an indefinite article is used. In any communication, whey you say, "To us", more than one person is referred to, and you cannot use an indefinite article which is signifying one in number. As such, you drop the article. The use of the in the other sentence
"The Chinese are a peace-loving people" or "The Chinese nation is peace-loving" You could say "To us, the Chinese (people), ... ", but you will omit the article in "us Chinese" because in your base sentence "Chinese" is used as a collective noun.