As a coordinator of a group of people who write hard science SF, I am happy to supply a list of US magazines, at least. In the 1930s days of pulps before electronic print media, there were many more outlets for short fiction. But here is what we now have, a list of our top ten in terms of circulation numbers of readers. I hope this helps and feel free to ask for more info and I can try to find it.
I guess that it depends on what you call a "good journal".
As far as scientific journals are concerned, possibly the most prestigious one, _Nature_, does include a 'Nature: Futures' section with a short hard SF story (or rather a 'short short' < 1000 words).
On the other hand, many SF magazines will publish hard SF — see Gloria's list. The two that comme immediately to mind _Analog Science Fiction and Fact_, obviously ; and more recently _Compelling Science Fiction_.