The phrase "a number of virtually" is correct and usable in written English.
It can be used when discussing an approximate quantity or extent of something that is nearly or almost a certain way.
Example: "There are a number of virtually identical solutions available for this problem."
Alternatives: "several nearly" or "many almost".
When someone takes a number of passages, virtually verbatim, from someone else's work (especially a work that is obscure or difficult to trace), fails to give attribution and represents them as original thoughts, that's plagiarism by even the most liberal definition.
A large number of virtually identical binding sites within repeats potentially induces a strong bias in a corresponding binding site model and could lead to wrong conclusions regarding preferential associations and constraints in distances to other TFBS.
Repetitive sequences with a considerable number of virtually identical sequences tend to impose repeat-specific characteristics of motifs in probabilistic approaches on repeat-containing sequence sets.
The main selling point of the service is that it enables multiple users to text-chat across a number of different devices – virtually in real-time.
However, there has been uproar in the lower house over a number of issues and virtually no legislative work has been done.
Obama and Reagan share a number of gifts but virtually no priorities.
Tylor's theory of the nature of religions and the resultant classification were so logical, convincing, and comprehensive that for a number of years they remained virtually unchallenged.
The ledger technology, which allows you to track bitcoin transactions in an immutable, irrefutable record that can also be applied to a number of scenarios for tracking virtually anything of value including content.
This year's milestone update brings a number of new features to virtually all of the Creative Cloud apps, including Photoshop, Lightroom, Illustrator, Premiere Pro and others, but it also marks the launch of Adobe Stock, the company's new stock content service based on its acquisition of Fotolia.
Windows netbooks/laptops can be quite affordable, and there are many options from a number of manufacturers to fit virtually every need or want.
