The phrase "are not only powerful" is correct and usable in written English.
It is typically used in a comparative context to emphasize that something has multiple significant qualities or attributes.
Example: "These new technologies are not only powerful but also highly efficient in solving complex problems."
Alternatives: "are not just powerful" or "are not solely powerful".
XML schemas are not only powerful implementations of metadata rules and constraints, but they are also subject to reuse.
Meanwhile, problem solving computing environments are not only powerful enough to solve complex problems but also are able to interact with human.
Today's key technological advances, in contrast, are not only powerful but inherently decentralized.
ANN's are not only powerful tools for defining relationships between parameters but also statistical means by which complex systems can be modeled.
"In approaching the season this way, we will be presenting works that are not only powerful and timely in their own right, but also speak to one another in continuing dialogue throughout the season". Such decisions are made by a production committee, which comprises academic department chairpersons, faculty, a box office manager, a marketing director, an assistant dean and others, Martin noted.
Expectations of heaviness are not only powerful enough to alter the perception of a single object's weight, but also continually drive the forces we use to lift the object when vision is unavailable.
And our findings were not only powerful in terms of the scope of our buying power, but perhaps more so, the size of our hearts.
Furthermore, this effect is not only powerful but also subliminal.
The original blast was not only powerful, according to the new results.
Her first serve is not only powerful, it also features excellent location.
As Ms. French, Ms. Saunders, Ms. Wax and Ms. Ullman have shown us, that kind of sisterhood is not only powerful, it's a giggle.
