[1] The authors depict the long-term changes in the South China Sea (SCS) summer monsoon using observational data of the Xisha Islands. The SCS monsoon is an important component of the Asian monsoon system, and its long-term changes have seldom been explored because of the unavailability of reliable data. The daily Xisha station observations provide an important source of information for understanding the changes in the monsoon. The intensity of the SCS summer monsoon measured by kinetic energy decreased significantly from 1958-1977 to 1978-2004. This change in monsoon was mainly caused by the weakening of the meridional component of lower tropospheric winds, and the weakening in the mean flow was signaled by decreased frequency of strong southerlies (6 m s À1 and above) of the daily winds. The weakening of the monsoon was also associated with increases in sea surface temperature and surface and lower tropospheric air temperatures over SCS, which occurred more frequently when daily surface temperature reaches 29°C and higher. The long-term warming of the lower troposphere was accompanied by cooling at the upper troposphere, destabilizing the local atmosphere. However, from 1958However, from -1977However, from to 1978However, from -2004, the long-term change in Xisha precipitation tended to decrease; furthermore, in fact, the station precipitation became less variable. Thus besides local air-sea interaction, large-scale atmospheric forcing also plays an important role in causing the long-term change of the Xisha precipitation. Indeed, the warming of Xisha was linked to large-scale warming in the tropics including SCS and was associated with smaller thermal contrast between the Asian continent and the surrounding oceans, which weakened monsoon circulation.

The first Mars exploration mission of China (Tianwen-1) is scheduled to be launched in 2020; a charged particle telescope, the Mars Energetic Particle Analyzer (MEPA), is carried as one of the payloads on the orbiter. The MEPA is designed to measure solar energetic particles (SEPs) and galactic cosmic rays (GCRs) in the near-Mars space and in the transfer orbit from Earth to Mars. Before the launch, the MEPA was calibrated in ground experiments with radioactive sources, electronic pulses, and accelerator beams. The calibration parameters, such as energy conversion constants, threshold values for the triggers, and particle identification criteria, were determined and have been stored for onboard use. The validity of the calibration parameters has been verified with radioactive sources and beams. The calibration results indicate that the MEPA can measure charged particles reliably, as designed, and that it can satisfy the requirements of the Tianwen-1 mission.

Lunar dust is regarded as the most crucial environmental problem on the Moon, and related research has crucially important scientific and technological interests. Here, we first reported the in situ measurements of lunar dust at the Chang'E‐3 landing site in the northern Mare Imbrium using temperature‐controlled sticky quartz crystal microbalance. The results showed that a total deposition mass at a height of 190 cm above the lunar surface during 12 lunar daytimes in the northern Mare Imbrium was about 0.0065 mg/cm2, corresponding to an annual deposition rate of ~21.4 μg/cm2, which is comparable with that of Apollo's result to some extent. The present researches are strategically important for future human and robotic lunar expeditions, and can provide a valuable reference for the design of dust protection for onboard payloads long‐term exposure to the lunar environment.

Wettability, as one of the important properties of solid surface, may influence heat and mass transfer in boiling process. Molecular dynamics method is employed to investigate the effects of wettability on normal and explosive boiling of ultra-thin liquid argon film absorbed on a heated solid aluminium surface in a confined space in present work. The initial three-phase molecular system is comprised of solid aluminium wall, liquid argon and vapour argon and is run for three different solid-liquid interfacial wettability (lyophilic, lyophobic and neutral surfaces), which achieves a balance at 90 K. After equilibrium period, two different jump temperatures degree, 150 and 350 K, are set on heat source layers separately to characterise the boiling phenomena, namely, low-temperature degree for normal boiling and hightemperature degree for explosive boiling in which temperature of solid wall is far beyond the critical temperature of liquid argon. The simulation results indicate that the wetting condition of solid-liquid interfacial surface have significant effects on both cases of boiling phenomena. Furthermore, the heat transfer rate with good wettability (lyophilic) is much higher than bad wettability (lyophobic) with same jump temperature degree.

Taiji-1, which is the first technical verification satellite of China’s Space Gravitational Wave Detection Program, was successfully launched on August 31, 2019. The mission aimed to investigate the key technologies used in space gravitational wave detection. The inertial sensor, which was one of the main payloads, measured the residual acceleration of the satellite, and verified the drag-free control technology. Its performance was crucial to the success of the Taiji-1 mission. To ensure its performance in orbit, the inertial sensor was fully evaluated prior to launch. Owing to the gravitational acceleration on the ground, it is impossible to verify all the properties of the inertial sensor in a routine laboratory. A feasible method to conduct such tests is to use a drop tower. To guarantee the safety of the inertial sensor, a substitute was used with similar structure and circuit design. A total of 20 falls in three groups were completed, a set of research methods was established, and the importance of conducting simulations before the drop tests was verified. For the first time, the switch of different circuit gains in a drop tower test has been achieved and the National Microgravity Laboratory of China (NMLC) drop tower’s residual accelerations in three dimensions were measured. The results demonstrated that the microgravity level of the drop tower can reach about 58 μg0 in the fall direction and 13 μg0 along the horizontal axes.