Research paper in Russia: intellectual rights

Who owns the exclusive rights to a research paper created as a duty assignment? What is a work-for-hire? What opportunities does the copyright holder reserve when transferring the article to the publisher under an exclusive license? What is an open license? What is the meaning of the term “self-plagiarism”? Is it acceptable to publish an article in several journals? These issues are considered in this work in the light of the requirements of the Civil code RF.