Considering the special walking behavior of astronauts on the lunar surface,to reduce the impact on their bones and improve safety during extravehicular operations and walking,a magnetorheological(MR)damping mechanism...Considering the special walking behavior of astronauts on the lunar surface,to reduce the impact on their bones and improve safety during extravehicular operations and walking,a magnetorheological(MR)damping mechanism of power assisted transmission joint used in a new type spacesuit is proposed.In order to improve the damping performance of the MR damper,the influence of the damper s structural parameters on both the output and dynamic adjustable range of the damping torque is examined.According to the theoretical mechanical model,the output damping torque is calculated,the finite element method is used to conduct numerical tests.At the same time,the structural parameters of the damper are optimized by the response surface methods.The results indicate that the simulated torque aligns with the theoretically designed torque,and the damping characteristics of the optimized structure are effectively improved by the response surface method.Compared with the initial structure,the damping torque is increased by 10.8%,and the dynamic adjustable range is expanded by 52.9%.展开更多
The lunar magma ocean hypothesis suggests that the primordial KREEP(an acronym of potassium(K),rare earth element(REE),and phosphorus(P))was the final product of fractional crystallization.However,the primordial KREEP...The lunar magma ocean hypothesis suggests that the primordial KREEP(an acronym of potassium(K),rare earth element(REE),and phosphorus(P))was the final product of fractional crystallization.However,the primordial KREEP(a.k.a.urKREEP)has never been identified in previous lunar samples or meteorites.The Moon is the focus of many countries’and agencies’space exploration plans,and with the advancement of technology,crewed missions have been proposed.We propose two candidate landing sites,located respectively in the northwest(9.5°W,0.9°S)and southeast(11.1°W,6.2°S)of Lalande crater(8.6°W,4.5°S),for future crewed missions,with the primary goal of sampling the speculated urKREEP.Both sites are situated on the Th-(a critical marker of KREEP)and silica-rich Lalande ejecta in the Mare Insularum and Mare Nubium,respectively.Their geolocations at the low latitude on the lunar nearside,the flat surface,and the low rock abundance suggest the sites are safe for landing and meet the needs of real-time Earth-Moon communication.The astronauts could perform many extravehicular activities,such as collecting KREEP-rich samples,screening clast samples,and drilling regolith cores,to gather a variety of samples,such as Lalande ejecta,basalts,Copernicus ejecta,and regolith.The returned samples are valuable to explore the speculated urKREEP,to reveal the relationship between heat-producing elements and volcanism,to refine the lunar cratering chronology function,and to investigate volatiles in the regolith.展开更多
基金The Natural Science Foundation of Shanghai(No.20ZR1401300).
文摘Considering the special walking behavior of astronauts on the lunar surface,to reduce the impact on their bones and improve safety during extravehicular operations and walking,a magnetorheological(MR)damping mechanism of power assisted transmission joint used in a new type spacesuit is proposed.In order to improve the damping performance of the MR damper,the influence of the damper s structural parameters on both the output and dynamic adjustable range of the damping torque is examined.According to the theoretical mechanical model,the output damping torque is calculated,the finite element method is used to conduct numerical tests.At the same time,the structural parameters of the damper are optimized by the response surface methods.The results indicate that the simulated torque aligns with the theoretically designed torque,and the damping characteristics of the optimized structure are effectively improved by the response surface method.Compared with the initial structure,the damping torque is increased by 10.8%,and the dynamic adjustable range is expanded by 52.9%.
基金supported by the National Key Research and Development Program of China(Grant No.2022YFF0503104)the National Natural Science Foundation of China(Grant Nos.42241111,62227901,and 42441826)+1 种基金the Macao Young Scholars Program(Grant No.AM201902)the Key Research Program of the Institute of Geology and Geophysics,Chinese Academy of Sciences(Grant No.IGGCAS-202401).
文摘The lunar magma ocean hypothesis suggests that the primordial KREEP(an acronym of potassium(K),rare earth element(REE),and phosphorus(P))was the final product of fractional crystallization.However,the primordial KREEP(a.k.a.urKREEP)has never been identified in previous lunar samples or meteorites.The Moon is the focus of many countries’and agencies’space exploration plans,and with the advancement of technology,crewed missions have been proposed.We propose two candidate landing sites,located respectively in the northwest(9.5°W,0.9°S)and southeast(11.1°W,6.2°S)of Lalande crater(8.6°W,4.5°S),for future crewed missions,with the primary goal of sampling the speculated urKREEP.Both sites are situated on the Th-(a critical marker of KREEP)and silica-rich Lalande ejecta in the Mare Insularum and Mare Nubium,respectively.Their geolocations at the low latitude on the lunar nearside,the flat surface,and the low rock abundance suggest the sites are safe for landing and meet the needs of real-time Earth-Moon communication.The astronauts could perform many extravehicular activities,such as collecting KREEP-rich samples,screening clast samples,and drilling regolith cores,to gather a variety of samples,such as Lalande ejecta,basalts,Copernicus ejecta,and regolith.The returned samples are valuable to explore the speculated urKREEP,to reveal the relationship between heat-producing elements and volcanism,to refine the lunar cratering chronology function,and to investigate volatiles in the regolith.
