A new ensemble-based targeted observational method and its application in the TPOS 2020.

Ensemble Kalman filter-based targeted observation is one of the best methods for determining the optimal observational array for oceanic buoy deployment. This study proposes a new algorithm suitable for a 'cross-region and cross-variable' approach by introducing a projection operator into the optimization process. A targeted observational analysis was conducted for El Niño-Southern Oscillation (ENSO) events in the tropical western Pacific for the Tropical Pacific Observation System (TPOS) 2020.

Ultrastretchable, Tough, and Notch-Insensitive Hydrogels Formed with Spherical Polymer Brush Crosslinker.

Spherical polymer brushes, poly(acrylic acid) (PAA)-grafted polystyrene nanoparticle (PAA@PS), are employed as the macro-crosslinker to prepare PAA hydrogels. Benefitting from the innumerable hydrogen bonds between highly entangled PAA chains both in bulk and on the polymer brush, the PAA/PAA@PS hydrogels combine desirable stretchability, toughness, and notch-insensitivity. The uniaxial tensile tests show a very high fracture elongation up to 9.