It is acceptable. Though the wording could be done differently to avoid comments like the one above.

Instead, include the following:

Discuss on Hacker News.

When we discuss something here, upvoting/downvoting plays an essential part is controlling where the conversation heads. So asking for people to upvote is not as positive as inviting them into the discussion.

By the way, welcome. Good post.

It's absolutely fine. As it's the mechanism for attracting a wider audience to something that benefit is being derived from, reminding them to up-vote the article seems mutually beneficial. You are not forcing anyone to do it.