Here is a list of publications that accept manuscripts from the Sciences and related fields. You may also want to search the General publications list.
Columbia Undergraduate Science Journal
A professional-level, open-access science journal that is committed to publishing manuscripts of the highest scholarship resulting from significant scientific research or outstanding scientific analysis.
McGill Science Undergraduate Research Journal
A student-run journal that offers undergraduate students from any university the opportunity to publish their findings to the McGill research community.
An online journal, produced by a consortium of UK universities with support from Oxford University Press, which publishes the best of student research from around the world.
Journal of Undergraduate Chemistry Research
A peer review journal that is published quarterly with papers of original research performed by undergraduates on all aspects of chemistry including analytical, organic, inorganic, physical, polymers and biochemistry.