Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander ...Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander with four-legged truss structure is proposed. In the premise of ensuring that the main and assistant structures of landing legs are not changed, six possible lander body structures of the new lander are put forward. Taking the section size of each component of lander as design variables, and taking the total mass of the structure as the objective function, the six structures are analyzed by using the software Altair. OptiStruct and the results show that the mass of the basic structure is the lightest, and it is selected as the final design scheme of lander due to its simple structure and convenient manufacture. The optimization on the selected lander structure is conducted, and the detailed results are presented.展开更多
Sustainable Livelihood Security(SLS)remains a rarely considered yet important issue for rural sustainability and natural resource management.Particularly in China,rural SLS research in a typical area is urgently neede...Sustainable Livelihood Security(SLS)remains a rarely considered yet important issue for rural sustainability and natural resource management.Particularly in China,rural SLS research in a typical area is urgently needed,but insufficient under the background of National Rural Revitalization and Ten-year Fishing Ban of Yangtze River.Focusing on the policy-targeted inland lake area,we proposed a Livelihood Security Analysis(LSA)framework by establishing an adaptive indicator system and integrating multiple econometrical and geographical methods.This study aims to evaluate the SLS in Poyang Lake Eco-economic Zone comprehensively from the three aspects of ecology,economy and society,analyze their spatial patterns,identify the main constraints,and finally give specific suggestions for improving rural sustainability management.The results showed that rural SLS in the inland great lake area tended to be vulnerable mainly due to the lagging economic efficiency and unbalanced social equality,and mediated by regional ecological characteristics.The overall SLS and Ecological Security Index(ESI)were higher in the north and lower in the south,while Economic Efficiency Index(EEI)and Social Equality Index(SEI)were at the middle level and circularly distributed around Nanchang City.The dominating factors which have greatly shaped the spatial pattern of SLS include rural per capita electricity consumption,fishery breeding area,population dependency ratio,urbanization rate,and fishery population.The obstacle degree is ranked as economic system>social system>ecological system.An outdated economy and incomplete social services are the main constraints,characterized by weak electricity consumption,limited beds in hospitals,low urbanization rate,deficient agricultural machinery power,and a small agricultural output value.Therefore,one urgent need is to activate the rural economy by reinforcing rural electric power facilities and promoting agricultural mechanization.In addition,transforming the peasants/fishermen to the non-agricultural sector should be accelerated,which will help to reduce ecological pressure,boost urban-rural integration and narrow the income gap.展开更多
基金Sponsored by the Project on Absorption of Intellects by Institutions of Higher Education for Academic Disciplinary Innovations(Grant No. B07018)
文摘Three kinds of possible structures of legged lander including monocoqe, semi-monocoqe and space frame are compared, and the lightest space frame structure is selected as the lander's structure. Then, a new lander with four-legged truss structure is proposed. In the premise of ensuring that the main and assistant structures of landing legs are not changed, six possible lander body structures of the new lander are put forward. Taking the section size of each component of lander as design variables, and taking the total mass of the structure as the objective function, the six structures are analyzed by using the software Altair. OptiStruct and the results show that the mass of the basic structure is the lightest, and it is selected as the final design scheme of lander due to its simple structure and convenient manufacture. The optimization on the selected lander structure is conducted, and the detailed results are presented.
基金The National Natural Science Foundation of China(41861036)The China Postdoctoral Science Foundation(2018M630738)+5 种基金The NaturalScience Foundation of Jiangxi Province(20192BAB213023)The Young Doctor Fund of Jiangxi Social Science Plan(17BJ38)The Humanitiesand Social Sciences Research Project of Jiangxi Universities(GL18238)The Postdoctoral Daily Fund of Jiangxi Province in 2018(2018RC29)The Jiangxi Provincial Postdoctoral Science Foundation(2019KY11)The Science and Technology Project of Education Department of Jiangxi Province(GJJ200504).
文摘Sustainable Livelihood Security(SLS)remains a rarely considered yet important issue for rural sustainability and natural resource management.Particularly in China,rural SLS research in a typical area is urgently needed,but insufficient under the background of National Rural Revitalization and Ten-year Fishing Ban of Yangtze River.Focusing on the policy-targeted inland lake area,we proposed a Livelihood Security Analysis(LSA)framework by establishing an adaptive indicator system and integrating multiple econometrical and geographical methods.This study aims to evaluate the SLS in Poyang Lake Eco-economic Zone comprehensively from the three aspects of ecology,economy and society,analyze their spatial patterns,identify the main constraints,and finally give specific suggestions for improving rural sustainability management.The results showed that rural SLS in the inland great lake area tended to be vulnerable mainly due to the lagging economic efficiency and unbalanced social equality,and mediated by regional ecological characteristics.The overall SLS and Ecological Security Index(ESI)were higher in the north and lower in the south,while Economic Efficiency Index(EEI)and Social Equality Index(SEI)were at the middle level and circularly distributed around Nanchang City.The dominating factors which have greatly shaped the spatial pattern of SLS include rural per capita electricity consumption,fishery breeding area,population dependency ratio,urbanization rate,and fishery population.The obstacle degree is ranked as economic system>social system>ecological system.An outdated economy and incomplete social services are the main constraints,characterized by weak electricity consumption,limited beds in hospitals,low urbanization rate,deficient agricultural machinery power,and a small agricultural output value.Therefore,one urgent need is to activate the rural economy by reinforcing rural electric power facilities and promoting agricultural mechanization.In addition,transforming the peasants/fishermen to the non-agricultural sector should be accelerated,which will help to reduce ecological pressure,boost urban-rural integration and narrow the income gap.
