Contents

01 January 2021
Vol 371, Issue 6524

About The Cover

Cover image expansion

COVER Multimodal electron microscopy reveals the three-dimensional nanostructure (gold) of reverse-osmosis membranes, as well as the need to control their polymer mass distribution for improved performance. Volume reconstructions with nanometer resolution are used as inputs for water flow simulations that reveal streamlines (gray; here, water flows from top to bottom). Minimizing "dead zones," thereby achieving a more uniform density throughout the membranes, is key to maximizing water production. See pages 31 and 72.
Data Visualization: Greg Foss, Texas Advanced Computing Center, University of Texas, Austin