Okay, if you click on the little down arrow next to the word '9 votes' you'll see a list of who voted for you - up votes have a + sign, and down votes are a - sign. The blog of the person who downvoted you is https://steemit.com/@triplej

Do you know why triplej did this to you? Did you have an argument?
If not, then we'll have to find someone to check all actions between you (as you may recall, ALL actions, every word, placed in Steemit remains for a long time, it cannot be deleted.