Recent Progress on Hydrogeodesy in China

Modern geodetic technologies,including high-precision ground-based gravity measurements,satellite gravimetry,satellite altimetry,Global Navigation Satellite Systems(GNSS),and Interferometric Synthetic Aperture Radar(InSAR),offer a wealth of observations for monitoring global hydrological processes with exceptional accuracy and spatio-temporal resolutions.Mass redistribution and Earth’s surface deformation over land related to global and regional water cycling can be inferred from modern gravimetry,altimetry,GNSS,and InSAR techniques.Hydrogeodesy becomes an emerging field of geodesy aiming to analyze the changes of water in the Earth system.The paper introduces the China’s advances in hydrogeodesy in recent years.It brings together multiple geodetic teams’work from China,showcasing the application of modern geodetic technologies in the field of hydrology,including research on terrestrial water storage,groundwater storage,glaciers/ice sheets,and reservoir water storage.

Developing polydopamine modified molybdenum disulfide/epoxy resin powder coatings with enhanced anticorrosion performance and wear resistance on magnesium lithium alloys

Epoxy resin powder coating has been successfully applied on the corrosion protection of magnesium lithium alloys.However,poor wear resistance and microcracks formed during the solidification have limited it extensive application.There are limited approaches to exploit such anti-corrosion and mechanical properties of magnesium lithium alloys.Herein,the epoxy resin powder coating with polydopamine modified molybdenum disulfide(MoS_(2)@PDA-EP powder coating with 0,0.1,0.2,0.5,1.0 wt.%loading)was well prepared by melt extrusion to investigate its anticorrosion performance and wear resistance.The results revealed that the addition of MoS_(2)@PDA enhanced the adhesion strength between coatings and alloys,wear resistance and corrosion protection of the powder coatings.Among them,the optimum was obtained by 0.2 wt.%MoS_(2)@PDA-EP powder coating which could be attributed to well dispersion and efficient adhesion with coating matrix.To conclude,MoS_(2)@PDA-EP powder coating is meaningfully beneficial for the anticorrosive and wear performance improvement of magnesium lithium alloys.

Two-dimensional molybdenum carbide(MXene)as an efficient nanoadditive for achieving superlubricity under ultrahigh pressure

In this study,a robust macroscale liquid superlubricity with a coefficient of friction of 0.004 was achieved by introducing molybdenum carbide(Mo_(2)CT_(x))MXene nanoparticles as lubricating additives in a lithium hexafluorophosphate-based ionic liquid at Si_(3)N_(4)-sapphire interfaces.The maximal contact pressure in the superlubricity state could reach 1.42 GPa,which far exceeds the limit of the superlubricity regime in previous studies.The results indicate that a composite tribofilm(mainly containing molybdenum oxide and phosphorus oxide)that formed at the interface by a tribochemical reaction contributed to the excellent antiwear performance.Furthermore,the extremely low shear strength of the tribofilm and the interlayers of Mo_(2)CT_(x)MXene contributed to the superlubricity.This work demonstrates the promising potential of Mo_(2)CT_(x)MXene in improving superlubricity properties,which could accelerate the application of superlubricity in mechanical systems.