Harold Hamm, an Oklahoma oil tycoon, has played a central role in reshaping energy policy by allying himself with President Trump.

© Loren Elliott for The New York Times

The reorganization reflects the ongoing shift in the federal government’s energy priorities: less renewable energy, more fossil fuels.

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A.I. has added urgency to the U.S. national laboratories that have been sites of cutting-edge scientific research, leading to deals with tech giants like Nvidia to speed up.

© Taylor Glascock for The New York Times