Researchers achieved record-breaking optical frequency transfer over 2067 km of field-deployed fiber with fractional instability of 2.9 x 10^-21 at one day. Using bias-free noise compensation based on digital RF phase recording and Hertz-level optical filtering, the system operates reliably under extreme noise levels of 5000 rad^2/Hz/km. This advance establishes a practical route toward large-scale optical clock networks and precision metrology using standard telecommunications infrastructure.

This collection features articles on Surface Treatment published in Smart Materials in Manufacturing. All articles are free to read and download.

This collection features articles on Alloy published in Smart Materials in Manufacturing. All articles are free to read and download.

A research team has found that soil type strongly determines how agricultural microbial communities process added carbon and nitrogen and whether denitrification releases nitrous oxide (N₂O) or converts it to harmless dinitrogen (N₂).

A research team has found that overlapping yak urine and dung patches in an alpine meadow do not simply add together to increase soil nitrous oxide emissions. 

Carbon fixation continues through winter

A paper published in Carbon Research reports that microbial inorganic carbon fixation remains active in Qinghai Lake, the largest saline lake in China, during the ice-covered season. The work focuses on how microorganisms assimilate inorganic carbon beneath lake ice, a period that has received far less attention than the summer open-water season despite its importance for annual lake carbon cycling.

The team, led by corresponding author Xiaoyan Li of Beijing Normal University, examined both light-dependent carbon fixation and dark-dependent carbon fixation in under-ice waters. Qinghai Lake, located on the Tibetan Plateau, provides a natural setting for this question because it is a high-altitude saline lake with prolonged seasonal ice cover, low temperatures, and distinctive microbial habitats.

A research team has discovered that bacterial rather than fungal denitrification serves as the primary driver for increased nitrous oxide (N₂O) emissions in paddy soils under warming conditions.