Orienting the future of bio-macromolecular electron microscopy

With 40 years of development, bio-macromolecule cryo-electron microscopy（cryo-EM） has completed its revolution in terms of resolution and currently plays a highly important role in structural biology study. According to different specimen states, cryo-EM involves three specific techniques： single-particle analysis（SPA）, electron tomography and subtomogram averaging, and electron diffraction. None of these three techniques have realized their full potential for solving the structures of bio-macromolecules and therefore need additional development. In this review, the current existing bottlenecks of cryo-EM SPA are discussed with theoretical analysis, which include the air–water interface during specimen cryo-vitrification, bio-macromolecular conformational heterogeneity, focus gradient within thick specimens, and electron radiation damage. Furthermore, potential solutions of these bottlenecks worthy of further investigation are proposed and discussed.

Fabrication of honeycomb AuTe monolayer with Dirac nodal line fermions

Two-dimensional honeycomb lattices show great potential in the realization of Dirac nodal line fermions(DNLFs).Here,we successfully synthesized a gold telluride(AuTe)monolayer by direct tellurizing an Au(111)substrate.Low energy electron diffraction measurements reveal that it is(2×2)AuTe layer stacked onto(3×3)Au(111)substrate.Moreover,scanning tunneling microscopy images show that the AuTe layer has a honeycomb structure.Scanning transmission electron microscopy reveals that it is a single-atom layer.In addition,first-principles calculations demonstrate that the honeycomb AuTe monolayer exhibits Dirac nodal line features protected by mirror symmetry,which is validated by angle-resolved photoemission spectra.Our results establish that monolayer AuTe can be a good candidate to investigate 2D DNLFs and provides opportunities to realize high-speed low-dissipation devices.

Rapid and Scalable Synthesis of Prussian Blue Analogue Nanocubes for Electrocatalytic Water Oxidation

Design and fabrication of earth-abundant electrocatalysts for oxygen evolution reaction(OER)is essential in improving the overall ef-ficiency of water electrolysis.In this work,we proposed a rapid and scalable synthesis route for fabricating Prussian blue analogue(PBA)nano cubes with tun able compositi ons and uniform particle size.With the structural ben efits of abu ndant surface sites,facile charge transfer behavior and favorable Co^(2+)-to-Co^(3+)pre-oxidation reaction,fast generation and accumulation of the catalytically active Co3+sites can be achieved for the CoCo PBA nano cubes,leadi ng to remarkable OER activity with simulta neously achieved low overpotential,large anodic current density,small Tafel slope as well as outstanding intrinsic activity.Of note,by performing Iong-term OER operati on,the CoCo PBA nano cubes exhibit a remarkable 5.5-folds performs nee enhan ceme nt,and obvious surface rec on struc-tion and the accumulation of high-valence Co species can be identified,proving the crucial role of pre-oxidation process in boosting the OER catalysis.This work proposed a un iversal approach for the rapid,scalable and con trollable fabricati on of the PBA-based materials,and the elucidation of the pre-oxidation process in facilitating the OER catalysis may provide useful guidanee for designing and optimizing advanced catalysts for energy-related electro-oxidation reactions in the future.

Reducing the climate shift in a new coupled model

Climate drift refers to spurious long-term changes that may be inherent in coupled models when external forcing factors are fixed. Understanding the sources of this drift and tuning the drift are crucial for obtaining reasonable simulations from coupled models. To prepare for the upcoming Coupled Model Intercomparison Project Phase 6, a new coupled model has been constructed based on the Community Earth System Model and the Grid-point Atmospheric Model of IAP LASG version 2. However, the surface temperature predicted by the new model is too underestimated, and this underestimation is caused by a type of climate drift, i.e., ‘‘initial shock.'' This study analyzes the source of the cold surface temperature from the perspective of energy balance and attempts to reduce the surface temperature drift by tuning the relative humidity threshold for low cloud.