The real difference between student work and professional work — on the most abstract level, at any rate — is that students write to please the reader, while professionals write to convince the reader. This has a number of different (nuanced) manifestations:
- Students tend to use colloquial language when they are unsure, trying to use social familiarity to bridge the gap; professionals dig into the analytical details
- Students tend to over-cite, thinking the reader wants to hear what other people said; professionals use citations mainly to bolster their own points and claims
- Students tend to wander and ramble, raising points that don't need to be raised and neglecting things that would be useful; professionals aim to be clear, concise, and complete.
Writing research papers is simpler than most students make it. For instance, the easiest way to 'emphasize the problem that needs to be solved' is to say explicitly what problem you're trying to solve, early in the introduction. You'll then go back for a lit review to frame the problem in disciplinary terms (thereby explaining why you picked up the problem and how you chose your approach), but put what you're trying to do first and foremost. Likewise, the paper should focus on your work, not anything else. You cite other research only to explain why you're doing what you're doing: showing what people tried that didn't work, and why you're doing something else; noting research that sets up the assumptions or methodology for your own work.
The trick to avoid sounding like a lab report is to keep the technical details of your research contained in your 'methods' section. You have to describe your procedure accurately enough so that others can replicate it if they so choose (so you can't really skimp), but if you keep it all short, sweet, and clinical, and all in that one section, most readers will skim through it quickly and move on to the results section. Don't focus on your methods, because that gives the impression that you're asking people to check your work; it's another student-trying-to-please-professor habit. Treat your methods description as a pro forma and ultimately boring necessity, like tying your shoelaces or putting on your seatbelt. It's got to be done, but it's not something any professional wants to dwell on.
Assume that everyone else will assume that you know what you're doing; assume that everyone else is a busy professional who doesn't want to waste time digging through trivia or idle thoughts. Write as though you have the authority to say what you want to say, and that people are reading for content, not to evaluate the quality of your work, because all that is true between professionals. You'll do fine.