I have recently needed to learn another programming language in a very
short amount of time for a project I'm working on. How can I show on
my resume that I am a dynamic and fast-learning fellow from the
Your resume should list the programming language that you learned.
And in the entry for the position, you might include something like "rapidly learned X in order to complete project Y"
Otherwise, your Cover Letter is where you expound on your ability to be a "dynamic and fast-learning fellow".
Also, I write articles in my field that is 'quite' well received (i.e.
I make 'technical' things easily swallow-able). Is this advantageous
to put in a resume, again as evidence that I could communicate well?
Yes, this sort of thing is often very advantageous.
If the articles are publicly-available, then you could reference them in a "Publications" section on your resume.