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
Since 2011,the Chinese Academy of Sciences(CAS)has implemented the Strategic Priority Program on Space Science(SPP).A series of scientific satellites have been developed and launched,such as Dark Matter Particle Explo...Since 2011,the Chinese Academy of Sciences(CAS)has implemented the Strategic Priority Program on Space Science(SPP).A series of scientific satellites have been developed and launched,such as Dark Matter Particle Explorer(DAMPE),Quantum Experiments at Space Scale(QUESS),Advanced Space-based Solar Observatory(ASO-S),Einstein Probe(EP),and significant scientific outcomes have been achieved.In order to plan the future space science missions in China,CAS has organized the Chinese space science community to conduct medium and long-term development strategy studies,and summarized the major scientific frontiers of space science as“One Black,Two Dark,Three Origins and Five Characterizations”.Five main scientific themes have been identified for China’s future breakthroughs,including the Extreme Universe,Space-Time Ripples,the Panoramic View of the Sun and Earth,the Habitable Planets,and Biological&Physical Science in Space.Space science satellite missions to be implemented before 2030 are proposed accordingly.展开更多
The possibility of the life origin in the stellar systems, located at a distance of ~200 pc from the solar system, was investigated. The stars, in the spectrums of which C (carbon), O (oxygen), N (nitrogen), and P (ph...The possibility of the life origin in the stellar systems, located at a distance of ~200 pc from the solar system, was investigated. The stars, in the spectrums of which C (carbon), O (oxygen), N (nitrogen), and P (phosphorus) are found, are called DNA-stars. Based on stellar abundances a new method for searching for habitable exoplanets has been developed and a list of 48 DNA-stars in the solar neighborhood, on which life is possible, has been defined. The quota of DNA-stars is equal 1.3% of the total amount of Hypatia Stellar Catalog. Only three DNA-stars out of selected 48 stars belong to the spectral class as our Sun (G2V). The closest to the solar system is the DNA-star with the number HIP 15510, which belongs to the G8V class and is 6 pc away from the solar system. Nine DNA-stars, which have the highest chemical similarity with solar spectrum, were identified. It is identified that one of these nine stars, HIP 24681, has six planets.展开更多
Considering current space debris situation in outer space environment,different methods for debris removal missions are proposed.In addition,advanced technologies are needed to be demonstrated for future human space e...Considering current space debris situation in outer space environment,different methods for debris removal missions are proposed.In addition,advanced technologies are needed to be demonstrated for future human space exploration programs.The main issue regarding to these missions is high mission cost for both debris removal missions and space environmental tests to achieve high maturity level for new space-usable technologies.Since,these missions are unavoidable for future of human space activities,a solution which can tackle these challenges is necessary.This paper will address to an idea which has the possibility to give a solution for facilitating technology readiness level(TRL)maturity tests by debris removal mission platform consideration.展开更多
In the early 19th century,Robert Morrison and William Milne,the first Protestant missionaries to China,commenced The Ultra-Ganges Missions,formally kicking off the Protestant missions in China and Southeast Asia.The U...In the early 19th century,Robert Morrison and William Milne,the first Protestant missionaries to China,commenced The Ultra-Ganges Missions,formally kicking off the Protestant missions in China and Southeast Asia.The Ultra-Ganges Missions not only marked a major milestone for the early missionary works of Protestantism,but also fueled the rise of Chinese modern press with its China-oriented periodicals such as The Chinese Monthly Magazine and The Indo-Chinese Gleaner.Based on the history of Protestantism in the 18th and 19th centuries,this article examines the origin of The Ultra-Ganges Missions and its periodical publication,in order to provide reference to the studies of Chinese Protestantism and China’s periodical press.展开更多
In the northwest of Shandong Province during Late Qing Dynasty,the struggle for survival among the villagers became social norm due to the fragility of the natural ecology,which was not only an important cause of loca...In the northwest of Shandong Province during Late Qing Dynasty,the struggle for survival among the villagers became social norm due to the fragility of the natural ecology,which was not only an important cause of local social unrest,but also complicated social relations.The potential anti-government tendencies of folk secret sects made them the targets of Qing government’s crackdown.In order to seek survival and development,the folk secret sects in northwest Shandong turned their eyes to Christian churches for political protect that was North China Mission of the American Board of Commissioners for Foreign Missions.With the help of secret sects,missionaries of the North China Mission gained a foothold in northwest Shandong.But they were not willing to provide political protect for secret sects.They only used the social ties of secret sects to wedge themselves into the rural society of northwest Shandong,hoping to establish Christian mission stations and develop Christian communities,not to integrate with secret sects.展开更多
The Bureau of High-Technology Research and Development (BHRD) BHRD is in charge of management for the research and; development activities in high-technology areas in CAS, including predicting the trends of high-techn...The Bureau of High-Technology Research and Development (BHRD) BHRD is in charge of management for the research and; development activities in high-technology areas in CAS, including predicting the trends of high-technology development in the light of the demands for technology which is strategic, forward-展开更多
The Academic Divisions of the Chinese Academy of Sciences (CAS) are vitally important and integral parts of the academy and were founded in June 1, 1955, six years after the establishment of the CAS. This was an impor...The Academic Divisions of the Chinese Academy of Sciences (CAS) are vitally important and integral parts of the academy and were founded in June 1, 1955, six years after the establishment of the CAS. This was an important event for both the CAS and the Chinese S&T community. The institution, which is composed of the most excellent Chinese scientists, has played an active role in strengthening the academic leadership of China’s S&T undertakings. Over the 40-odd years of ups and downs, the development of Academic Divisions could be characterized by four phases: laying the foundation展开更多
Generally, the Shenzhou 8 and Shenzhou 9 spaceships were similar in technology status. As the Shenzhou 9 spaceship implemented the manned rendezvous and docking mission, the program was appropriately modified. There a...Generally, the Shenzhou 8 and Shenzhou 9 spaceships were similar in technology status. As the Shenzhou 9 spaceship implemented the manned rendezvous and docking mission, the program was appropriately modified. There are 10 primary differences between the two missions.展开更多
Accurate and highly efficient approaches to obtain mission opportunities are still the goals of mission planners of interplanetary explorations.The search for launch opportunities not only determines the specified lau...Accurate and highly efficient approaches to obtain mission opportunities are still the goals of mission planners of interplanetary explorations.The search for launch opportunities not only determines the specified launch window of the mission but also presents the performance requirements for the interplanetary probe and its launch vehicle.An effective method, namely the two-dimensional launch window method, is developed from a completely new perspective to determine all the launch opportunities of the mission in this research.For a fixed launch time,the method to determine all the time windows in the dimension of Time-of-Flight(TOF) is firstly proposed and these time windows represent all the launch opportunities for the given launch time.And then, the two-dimensional launch window method is proposed, which computes the time windows in both the launch time and TOF dimensions to achieve all launch opportunities of the mission.Numerical examples are provided to demonstrate the accuracy and high efficiency of the method.Compared with the widely-used pock-chop plot method, the proposed method reduces the computational time by two orders of magnitude for the same search precision, and thus is especially suitable for the cases involving rapid, high-precision, and/or large-scale searches for mission opportunities.展开更多
This study concentrates of the new generation of the agile （AEOS）. AEOS is a key study object on management problems earth observation satellite in many countries because of its many advantages over non-agile satell...This study concentrates of the new generation of the agile （AEOS）. AEOS is a key study object on management problems earth observation satellite in many countries because of its many advantages over non-agile satellites. Hence, the mission planning and scheduling of AEOS is a popular research problem. This research investigates AEOS characteristics and establishes a mission planning model based on the working principle and constraints of AEOS as per analysis. To solve the scheduling issue of AEOS, several improved algorithms are developed. Simulation results suggest that these algorithms are effective.展开更多
A comprehensive mission sensitivity analysis index based on Sobol's index called global mission sensitivity( GMS) was proposed in this paper which focused on analyzing the mission sensitivity of components of phas...A comprehensive mission sensitivity analysis index based on Sobol's index called global mission sensitivity( GMS) was proposed in this paper which focused on analyzing the mission sensitivity of components of phased mission systems( PMS). The simulation strategy of GMS based on a Petri net and Monte Carlo method was presented which had broad applicability. Finally,the GMS and Birnbaum's sensitivity of components in a PMS example were compared. The GMS of component is demonstrated to be more adaptable to reflect the component mission sensitivity when the rated reliability parameters of components cannot be obtained, and components have state dependency or the system is subjected to common cause failure.展开更多
In 2016, China chose April 24 as the Space Day of China to mark the launch of its first satellite Dongfanghong-1 into space on April 24, 1970, and has celebrated it ever since. To commemorate the upcoming 10th Space D...In 2016, China chose April 24 as the Space Day of China to mark the launch of its first satellite Dongfanghong-1 into space on April 24, 1970, and has celebrated it ever since. To commemorate the upcoming 10th Space Day of China, the first episode of the six-episode documentary series Missions to the Moon will premiere exclusively on Youku, a leading streaming platform in China, at 6 p.m. on April 23, 2025, and one episode will be updated weekly later. Famous actor Wu Jing serves as the storyteller in this documentary, leading audiences through awe-inspiring journeys from the thunderstorm at the launch site to the moon expeditions across deserts and forests, and from the scientific exploration of lunar soil to the dream relay of two generations of chief designers. Spanning the cosmic odyssey of 380,000 kilometers, this documentary showcases the soaring ambition of the Chinese people who “dare to fly to the moon.” This is a moonlight epic written for the future and an invitation to all dream chasers.展开更多
Funding information was not reported in the original paper.Funding:This study was conducted within the National Centre for Sustainable Mobility(MOST)and received funding from the European Union Next-Generation EU(PIAN...Funding information was not reported in the original paper.Funding:This study was conducted within the National Centre for Sustainable Mobility(MOST)and received funding from the European Union Next-Generation EU(PIANO NAZIONALE DI RIPRESA E RESILIENZA(PNRR)-MISSIONE 4 COMPONENTE 2,INVESTIMENTO 1.4-D.D.103317/06/2022,CN00000023).This manuscript reflects the authors’views and opinions only,neither the European Union nor the European Commis-sion can be considered responsible for them.展开更多
Exposure of the human body to the aerospace environment is capable of producing various physiological changes,which contributes to greater susceptibility of acquiring viral and/or bacterial infections.Objective:To rev...Exposure of the human body to the aerospace environment is capable of producing various physiological changes,which contributes to greater susceptibility of acquiring viral and/or bacterial infections.Objective:To review studies on the use of antimicrobials in space to provide up-to-date information on the treatment of infectious diseases and contribute to the safety and well-being of astronauts on space voyages.Method:Integrative literature review,using DeCS(https://decs.bvsalud.org/)and PubMed(https://pubmed.ncbi.nlm.nih.gov/).Results and Discussion:Prolonged exposure to microgravity,radiation,and confinement can potentially affect the dynamics of interactions between microorganisms and Homo sapiens,causing astronauts to be more susceptible to infections in the aerospace environment.This context becomes more complex when we consider the greater possibility of drug-resistant bacterial strains emerging-due to radiation-related mutations-and the conditions that affect antimicrobial stability,especially excessive vibrations,a carbon dioxide-rich atmosphere,and variations in humidity temperature fluctuations.Additionally,physiological changes experienced by humans in the extraterrestrial environment-e.g.,cardiovascular,respiratory,and renal-can alter the pharmacokinetics of antimicrobials.Conclusion:Understanding the context in which astronauts are inserted,the risks involved,and how to avoid theses is essential for ensuring the safety and continuity of space missions with regards to diseases and the use of antimicrobials,which will allow humanity in space to have a“long and prosperous life”.展开更多
China's research-oriented icebreaker Xuelong,or Snow Dragon,arrived in Shanghai on April 8,marking the completion of key missions in the country's 41st Antarctic expedition.The expedition involves 516 members ...China's research-oriented icebreaker Xuelong,or Snow Dragon,arrived in Shanghai on April 8,marking the completion of key missions in the country's 41st Antarctic expedition.The expedition involves 516 members from 118 domestic and international institutions and is being carried out by three vessels.展开更多
Background: Missions organized by international societies and humanitarian organizations play a significant role in saving many patients’ lives and improving their quality of life, despite the surrounding frustrating...Background: Missions organized by international societies and humanitarian organizations play a significant role in saving many patients’ lives and improving their quality of life, despite the surrounding frustrating conditions. Methods: A team of plastic surgery volunteers was sent to Yemen by the KSHARC. Results: A successful mission was performed on 62 patients who underwent surgery, with more than 900 patients examined and receiving appropriate medications. Conclusion: Missions in disaster-affected areas are of great importance. The role of missions and humanitarian organizations should be empowered.展开更多
The ever-changing environment and complex combat missions create new demands for the formation of mission groups of unmanned combat agents.This study aims to address the problem of dynamic construction of mission grou...The ever-changing environment and complex combat missions create new demands for the formation of mission groups of unmanned combat agents.This study aims to address the problem of dynamic construction of mission groups under new requirements.Agents are heterogeneous,and a group formation method must dynamically form new groups in circumstances where missions are constantly being explored.In our method,a group formation strategy that combines heuristic rules and response threshold models is proposed to dynamically adjust the members of the mission group and adapt to the needs of new missions.The degree of matching between the mission requirements and the group’s capabilities,and the communication cost of group formation are used as indicators to evaluate the quality of the group.The response threshold method and the ant colony algorithm are selected as the comparison algorithms in the simulations.The results show that the grouping scheme obtained by the proposed method is superior to those of the comparison methods.展开更多
Combat effectiveness of unmanned aerial vehicle(UAV)formations can be severely affected by the mission execution reliability.During the practical execution phase,there are inevitable risks where UAVs being destroyed o...Combat effectiveness of unmanned aerial vehicle(UAV)formations can be severely affected by the mission execution reliability.During the practical execution phase,there are inevitable risks where UAVs being destroyed or targets failed to be executed.To improve the mission reliability,a resilient mission planning framework integrates task pre-and re-assignment modules is developed in this paper.In the task pre-assignment phase,to guarantee the mission reliability,probability constraints regarding the minimum mission success rate are imposed to establish a multi-objective optimization model.And an improved genetic algorithm with the multi-population mechanism and specifically designed evolutionary operators is used for efficient solution.As in the task-reassignment phase,possible trigger events are first analyzed.A real-time contract net protocol-based algorithm is then proposed to address the corresponding emergency scenario.And the dual objective used in the former phase is adapted into a single objective to keep a consistent combat intention.Three cases of different scales demonstrate that the two modules cooperate well with each other.On the one hand,the pre-assignment module can generate high-reliability mission schedules as an elaborate mathematical model is introduced.On the other hand,the re-assignment module can efficiently respond to various emergencies and adjust the original schedule within a millisecond.The corresponding animation is accessible at bilibili.com/video/BV12t421w7EE for better illustration.展开更多
The service load on high temperature rotating components of aero-engines generally exhibits flight mission characteristics. The general shape of the load spectrum is that Type Ⅲ/Ⅳ cyclic loading and creep loading ar...The service load on high temperature rotating components of aero-engines generally exhibits flight mission characteristics. The general shape of the load spectrum is that Type Ⅲ/Ⅳ cyclic loading and creep loading are superimposed on Type Ⅰ cyclic loading. Meanwhile, the sequence of the Type Ⅲ/Ⅳ cyclic and creep loading varies with mission. This work performed load spectrum test with this characteristic on the Ni-based alloy FGH96. Then a life prediction method was developed based on the Chaboche fatigue damage accumulation model and a modified time fraction model. Creep followed by Fatigue (C-F) test was carried out to reveal the creep-fatigue interaction and calibrate parameters. The results show that most test results fall within the 2-fold deviation band. The sequence of creep-fatigue loading within the load spectrum exhibited a limited effect on life. Finally, simplified methods were developed to improve analysis efficiency, and cases where simplified methods could replace the proposed method were discussed.展开更多
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.
基金Supported by Consultation and Evaluation Program on Academic Divisions of the Chinese Academy of Sciences(2022-DX02-B-007)。
文摘Since 2011,the Chinese Academy of Sciences(CAS)has implemented the Strategic Priority Program on Space Science(SPP).A series of scientific satellites have been developed and launched,such as Dark Matter Particle Explorer(DAMPE),Quantum Experiments at Space Scale(QUESS),Advanced Space-based Solar Observatory(ASO-S),Einstein Probe(EP),and significant scientific outcomes have been achieved.In order to plan the future space science missions in China,CAS has organized the Chinese space science community to conduct medium and long-term development strategy studies,and summarized the major scientific frontiers of space science as“One Black,Two Dark,Three Origins and Five Characterizations”.Five main scientific themes have been identified for China’s future breakthroughs,including the Extreme Universe,Space-Time Ripples,the Panoramic View of the Sun and Earth,the Habitable Planets,and Biological&Physical Science in Space.Space science satellite missions to be implemented before 2030 are proposed accordingly.
文摘The possibility of the life origin in the stellar systems, located at a distance of ~200 pc from the solar system, was investigated. The stars, in the spectrums of which C (carbon), O (oxygen), N (nitrogen), and P (phosphorus) are found, are called DNA-stars. Based on stellar abundances a new method for searching for habitable exoplanets has been developed and a list of 48 DNA-stars in the solar neighborhood, on which life is possible, has been defined. The quota of DNA-stars is equal 1.3% of the total amount of Hypatia Stellar Catalog. Only three DNA-stars out of selected 48 stars belong to the spectral class as our Sun (G2V). The closest to the solar system is the DNA-star with the number HIP 15510, which belongs to the G8V class and is 6 pc away from the solar system. Nine DNA-stars, which have the highest chemical similarity with solar spectrum, were identified. It is identified that one of these nine stars, HIP 24681, has six planets.
基金Supported by the National Natural Science Foundation of China(11572037)
文摘Considering current space debris situation in outer space environment,different methods for debris removal missions are proposed.In addition,advanced technologies are needed to be demonstrated for future human space exploration programs.The main issue regarding to these missions is high mission cost for both debris removal missions and space environmental tests to achieve high maturity level for new space-usable technologies.Since,these missions are unavoidable for future of human space activities,a solution which can tackle these challenges is necessary.This paper will address to an idea which has the possibility to give a solution for facilitating technology readiness level(TRL)maturity tests by debris removal mission platform consideration.
文摘In the early 19th century,Robert Morrison and William Milne,the first Protestant missionaries to China,commenced The Ultra-Ganges Missions,formally kicking off the Protestant missions in China and Southeast Asia.The Ultra-Ganges Missions not only marked a major milestone for the early missionary works of Protestantism,but also fueled the rise of Chinese modern press with its China-oriented periodicals such as The Chinese Monthly Magazine and The Indo-Chinese Gleaner.Based on the history of Protestantism in the 18th and 19th centuries,this article examines the origin of The Ultra-Ganges Missions and its periodical publication,in order to provide reference to the studies of Chinese Protestantism and China’s periodical press.
文摘In the northwest of Shandong Province during Late Qing Dynasty,the struggle for survival among the villagers became social norm due to the fragility of the natural ecology,which was not only an important cause of local social unrest,but also complicated social relations.The potential anti-government tendencies of folk secret sects made them the targets of Qing government’s crackdown.In order to seek survival and development,the folk secret sects in northwest Shandong turned their eyes to Christian churches for political protect that was North China Mission of the American Board of Commissioners for Foreign Missions.With the help of secret sects,missionaries of the North China Mission gained a foothold in northwest Shandong.But they were not willing to provide political protect for secret sects.They only used the social ties of secret sects to wedge themselves into the rural society of northwest Shandong,hoping to establish Christian mission stations and develop Christian communities,not to integrate with secret sects.
文摘The Bureau of High-Technology Research and Development (BHRD) BHRD is in charge of management for the research and; development activities in high-technology areas in CAS, including predicting the trends of high-technology development in the light of the demands for technology which is strategic, forward-
文摘The Academic Divisions of the Chinese Academy of Sciences (CAS) are vitally important and integral parts of the academy and were founded in June 1, 1955, six years after the establishment of the CAS. This was an important event for both the CAS and the Chinese S&T community. The institution, which is composed of the most excellent Chinese scientists, has played an active role in strengthening the academic leadership of China’s S&T undertakings. Over the 40-odd years of ups and downs, the development of Academic Divisions could be characterized by four phases: laying the foundation
文摘Generally, the Shenzhou 8 and Shenzhou 9 spaceships were similar in technology status. As the Shenzhou 9 spaceship implemented the manned rendezvous and docking mission, the program was appropriately modified. There are 10 primary differences between the two missions.
基金co-supported by the National Natural Science Foundation of China(No.11502300)the Science and Technology on Electro-optic Control Laboratory and the Aerospace Science Foundation of China(No.20165196018)。
文摘Accurate and highly efficient approaches to obtain mission opportunities are still the goals of mission planners of interplanetary explorations.The search for launch opportunities not only determines the specified launch window of the mission but also presents the performance requirements for the interplanetary probe and its launch vehicle.An effective method, namely the two-dimensional launch window method, is developed from a completely new perspective to determine all the launch opportunities of the mission in this research.For a fixed launch time,the method to determine all the time windows in the dimension of Time-of-Flight(TOF) is firstly proposed and these time windows represent all the launch opportunities for the given launch time.And then, the two-dimensional launch window method is proposed, which computes the time windows in both the launch time and TOF dimensions to achieve all launch opportunities of the mission.Numerical examples are provided to demonstrate the accuracy and high efficiency of the method.Compared with the widely-used pock-chop plot method, the proposed method reduces the computational time by two orders of magnitude for the same search precision, and thus is especially suitable for the cases involving rapid, high-precision, and/or large-scale searches for mission opportunities.
基金supported by the National Natural Science Foundation of China(7127106671171065+1 种基金71202168)the Natural Science Foundation of Heilongjiang Province(GC13D506)
文摘This study concentrates of the new generation of the agile （AEOS）. AEOS is a key study object on management problems earth observation satellite in many countries because of its many advantages over non-agile satellites. Hence, the mission planning and scheduling of AEOS is a popular research problem. This research investigates AEOS characteristics and establishes a mission planning model based on the working principle and constraints of AEOS as per analysis. To solve the scheduling issue of AEOS, several improved algorithms are developed. Simulation results suggest that these algorithms are effective.
基金National Natural Science Foundation of China(No.71071159)
文摘A comprehensive mission sensitivity analysis index based on Sobol's index called global mission sensitivity( GMS) was proposed in this paper which focused on analyzing the mission sensitivity of components of phased mission systems( PMS). The simulation strategy of GMS based on a Petri net and Monte Carlo method was presented which had broad applicability. Finally,the GMS and Birnbaum's sensitivity of components in a PMS example were compared. The GMS of component is demonstrated to be more adaptable to reflect the component mission sensitivity when the rated reliability parameters of components cannot be obtained, and components have state dependency or the system is subjected to common cause failure.
文摘In 2016, China chose April 24 as the Space Day of China to mark the launch of its first satellite Dongfanghong-1 into space on April 24, 1970, and has celebrated it ever since. To commemorate the upcoming 10th Space Day of China, the first episode of the six-episode documentary series Missions to the Moon will premiere exclusively on Youku, a leading streaming platform in China, at 6 p.m. on April 23, 2025, and one episode will be updated weekly later. Famous actor Wu Jing serves as the storyteller in this documentary, leading audiences through awe-inspiring journeys from the thunderstorm at the launch site to the moon expeditions across deserts and forests, and from the scientific exploration of lunar soil to the dream relay of two generations of chief designers. Spanning the cosmic odyssey of 380,000 kilometers, this documentary showcases the soaring ambition of the Chinese people who “dare to fly to the moon.” This is a moonlight epic written for the future and an invitation to all dream chasers.
文摘Funding information was not reported in the original paper.Funding:This study was conducted within the National Centre for Sustainable Mobility(MOST)and received funding from the European Union Next-Generation EU(PIANO NAZIONALE DI RIPRESA E RESILIENZA(PNRR)-MISSIONE 4 COMPONENTE 2,INVESTIMENTO 1.4-D.D.103317/06/2022,CN00000023).This manuscript reflects the authors’views and opinions only,neither the European Union nor the European Commis-sion can be considered responsible for them.
文摘Exposure of the human body to the aerospace environment is capable of producing various physiological changes,which contributes to greater susceptibility of acquiring viral and/or bacterial infections.Objective:To review studies on the use of antimicrobials in space to provide up-to-date information on the treatment of infectious diseases and contribute to the safety and well-being of astronauts on space voyages.Method:Integrative literature review,using DeCS(https://decs.bvsalud.org/)and PubMed(https://pubmed.ncbi.nlm.nih.gov/).Results and Discussion:Prolonged exposure to microgravity,radiation,and confinement can potentially affect the dynamics of interactions between microorganisms and Homo sapiens,causing astronauts to be more susceptible to infections in the aerospace environment.This context becomes more complex when we consider the greater possibility of drug-resistant bacterial strains emerging-due to radiation-related mutations-and the conditions that affect antimicrobial stability,especially excessive vibrations,a carbon dioxide-rich atmosphere,and variations in humidity temperature fluctuations.Additionally,physiological changes experienced by humans in the extraterrestrial environment-e.g.,cardiovascular,respiratory,and renal-can alter the pharmacokinetics of antimicrobials.Conclusion:Understanding the context in which astronauts are inserted,the risks involved,and how to avoid theses is essential for ensuring the safety and continuity of space missions with regards to diseases and the use of antimicrobials,which will allow humanity in space to have a“long and prosperous life”.
文摘China's research-oriented icebreaker Xuelong,or Snow Dragon,arrived in Shanghai on April 8,marking the completion of key missions in the country's 41st Antarctic expedition.The expedition involves 516 members from 118 domestic and international institutions and is being carried out by three vessels.
文摘Background: Missions organized by international societies and humanitarian organizations play a significant role in saving many patients’ lives and improving their quality of life, despite the surrounding frustrating conditions. Methods: A team of plastic surgery volunteers was sent to Yemen by the KSHARC. Results: A successful mission was performed on 62 patients who underwent surgery, with more than 900 patients examined and receiving appropriate medications. Conclusion: Missions in disaster-affected areas are of great importance. The role of missions and humanitarian organizations should be empowered.
基金Project supported by the National Natural Science Foundation of China(No.61773066)the Foundation of China Academy of Railway Sciences Corporation Limited(No.2019YJ071)。
文摘The ever-changing environment and complex combat missions create new demands for the formation of mission groups of unmanned combat agents.This study aims to address the problem of dynamic construction of mission groups under new requirements.Agents are heterogeneous,and a group formation method must dynamically form new groups in circumstances where missions are constantly being explored.In our method,a group formation strategy that combines heuristic rules and response threshold models is proposed to dynamically adjust the members of the mission group and adapt to the needs of new missions.The degree of matching between the mission requirements and the group’s capabilities,and the communication cost of group formation are used as indicators to evaluate the quality of the group.The response threshold method and the ant colony algorithm are selected as the comparison algorithms in the simulations.The results show that the grouping scheme obtained by the proposed method is superior to those of the comparison methods.
基金supported by the National Key Research and Development Plan(Grant No.2021YFB3302501)the National Natural Science Foundation of China(Grant Nos.12102077,12161076,U2241263).
文摘Combat effectiveness of unmanned aerial vehicle(UAV)formations can be severely affected by the mission execution reliability.During the practical execution phase,there are inevitable risks where UAVs being destroyed or targets failed to be executed.To improve the mission reliability,a resilient mission planning framework integrates task pre-and re-assignment modules is developed in this paper.In the task pre-assignment phase,to guarantee the mission reliability,probability constraints regarding the minimum mission success rate are imposed to establish a multi-objective optimization model.And an improved genetic algorithm with the multi-population mechanism and specifically designed evolutionary operators is used for efficient solution.As in the task-reassignment phase,possible trigger events are first analyzed.A real-time contract net protocol-based algorithm is then proposed to address the corresponding emergency scenario.And the dual objective used in the former phase is adapted into a single objective to keep a consistent combat intention.Three cases of different scales demonstrate that the two modules cooperate well with each other.On the one hand,the pre-assignment module can generate high-reliability mission schedules as an elaborate mathematical model is introduced.On the other hand,the re-assignment module can efficiently respond to various emergencies and adjust the original schedule within a millisecond.The corresponding animation is accessible at bilibili.com/video/BV12t421w7EE for better illustration.
基金supported by the National Science and Technology Major Project of China(No.J2019-IV-0017-0085)the National Natural Science Foundation of China(Nos.12172021,52205177)the Natural Science Foundation of Hunan Province,China(No.2021JJ40741).
文摘The service load on high temperature rotating components of aero-engines generally exhibits flight mission characteristics. The general shape of the load spectrum is that Type Ⅲ/Ⅳ cyclic loading and creep loading are superimposed on Type Ⅰ cyclic loading. Meanwhile, the sequence of the Type Ⅲ/Ⅳ cyclic and creep loading varies with mission. This work performed load spectrum test with this characteristic on the Ni-based alloy FGH96. Then a life prediction method was developed based on the Chaboche fatigue damage accumulation model and a modified time fraction model. Creep followed by Fatigue (C-F) test was carried out to reveal the creep-fatigue interaction and calibrate parameters. The results show that most test results fall within the 2-fold deviation band. The sequence of creep-fatigue loading within the load spectrum exhibited a limited effect on life. Finally, simplified methods were developed to improve analysis efficiency, and cases where simplified methods could replace the proposed method were discussed.
