Experimental atomic physicists have discovered there is a maximum amount of electrical resistance, or resistivity, that can result from collisions between electrons. A team from the University of Toronto, L’École Normale Supérieure in Paris and Lehigh University in Pennsylvania studied ultracold potassium atoms cooled to near absolute zero. They found when increasing the rate at which atoms collide, the resulting resistance eventually stops increasing, offering new insights into what causes resistivity at the microscopic level.

China’s power grid is set to undergo major transformation by 2030 as wind and solar energy expand rapidly. A new article in Engineering identifies five typical grid development scenarios and key technical challenges in power supply, grid stability, and equipment performance. It also proposes targeted research directions to support secure, low-carbon operation of the future power system, offering clear guidance for technology innovation and grid upgrading.

Peptides are important biological compounds that carry key information for many biological processes. However, accurately reading their sequences has long been a challenge. In a new study, researchers developed a mass-spectrometry-based approach that attaches a coumarin-derived tag to the N-terminus of each peptide, enabling accurate and reliable sequencing of even short peptides, directly from spectral data without relying on protein sequence databases. This helps in identifying novel peptides.