I'm looking for a website or magazine that has interesting, well-written and scientific articles.
There's ISAE that is issuing Scienca Revuo every now and then. On their website there's a huge archive of scientific articles that date back until 1949. Unfortunately due to lack of contributions recently not that many issues could be issued. Therefore there's now a blogish website for more casual stuff on science.
Another interesting resource is http://teleskopo.com/
I have written 16 articles in Esperanto, 3 of which I would count as addressing your request:
La Lingvo-Bariero kiel Beletra Rimedo
Miraklo de Morley
Formulo por la Leĝo de Engel
The articles are available at: http://web.archive.org/web/20170830115134/http://www.public-domain-materials.com/dosierujo-artikoloj-en-esperanto.html