By Nikolaus Kriegeskorte [CC BY 3.0 (http://creativecommons.org/licenses/by/3.0)], via Wikimedia Commons
STRUCTURING AND WRITING A SCIENTIFIC ARTICLE:
Your professor has indicated that you should follow one of two possible formats for structuring your paper. We will describe those below and then give resources for general advice on writing scientific articles. They might help in terms of style or understanding.
One style you can use is the style of the journal, The Physical Review. The guide for this can be found HERE.
Another style you can use is suggested by your professor:
Abstract, Introduction, Background and Theory, Experimental Apparatus and Methods, Discussion of Results, Conclusion, References, Appendices.
If you need more information on scientific writing in general please see the resources below. They may help you better understand the different sections of a paper and how to go about writing them.
There is an excellent article called "11 Steps to Structuring a Science Paper Editors Will Take Seriously". The author goes in depth about not only how to structure the paper, but details about what should go into each section and how those sections should be formatted. He goes into great detail while still being concise and readable.
One example of his suggestions is that when writing the paper one should write the paper in the following order: figures and tables, methods, results, discussion, conclusion, introduction, abstract, title, keywords, acknowledgements, references. This is counterintuitive considering this is not the order in which the paper is ultimately organized, but he discusses why this order helps you in making your writing clear and coherent.
Another useful resource is Southwestern University's Guide to Writing in Physics. This short guide gives an overview of literature in physics, the parts of a research article (which can differ slightly from the organization of the typical scientific research article), and using figures and equations.
Writing Guides--Writing in the Sciences (Colorado State University): This set of webpages walks you through how to write abstracts, review papers, scientific papers, policy statements, and posters among other things. It gives you tips on how to do these things well.
Graduate Scientific Writing Resource (Duke University): This website provides a guide to effective writing in the sciences. It is not meant as a step by step guide through the types of scientific writing. Rather, it is designed to teach you to make your writing more clear and effective for your audience. There are little exercises with the lessons to help you practice what you learn.
ABSTRACTS:
In particular, you might be asked to write an abstract from a paper. You do not go about it the way you might write a paper--just writing it fairly freeform. It follows a fairly strict construction based on the text and is used to introduce your readers to the paper and advertise it in collections and databases. Here are a few websites that go into detail about writing your abstract:
The Writing Center at UNC-Chapel Hill--Abstracts
How to Write a Good Abstract for a Scientific Paper or Conference Presentation