Space exploration is significant for scientific innovation,resource utilization,and planetary security.Space exploration involves several systems including satellites,space suits,communication systems,and robotics,whi...Space exploration is significant for scientific innovation,resource utilization,and planetary security.Space exploration involves several systems including satellites,space suits,communication systems,and robotics,which have to function under harsh space conditions such as extreme temperatures(−270 to 1650℃),microgravity(10^(-6)g),unhealthy humidity(<20%RH or>60%RH),high atmospheric pressure(~1450 psi),and radiation(4000–5000 mSv).Conventional energy-harvesting technologies(solar cells,fuel cells,and nuclear energy),that are normally used to power these space systems have certain limitations(e.g.,sunlight dependence,weight,degradation,big size,high cost,low capacity,radioactivity,complexity,and low efficiency).The constraints in conventional energy resources have made it imperative to look for non-conventional yet efficient alternatives.A great potential for enhancing efficiency,sustainability,and mission duration in space exploration can be offered by integrating triboelectric nanogenerators(TENGs)with existing energy sources.Recently,the potential of TENG including energy harvesting(from vibrations/movements in satellites and spacecraft),self-powered sensing,and microgravity,for multiple applications in different space missions has been discussed.This review comprehensively covers the use of TENGs for various space applications,such as planetary exploration missions(Mars environment monitoring),manned space equipment,In-orbit robotic operations/collision monitoring,spacecraft’s design and structural health monitoring,Aeronautical systems,and conventional energy harvesting(solar and nuclear).This review also discusses the use of self-powered TENG sensors for deep space object perception.At the same time,this review compares TENGs with conventional energy harvesting technologies for space systems.Lastly,this review talks about energy harvesting in satellites,TENG-based satellite communication systems,and future practical implementation challenges(with possible solutions).展开更多
Acute exposure to high altitude can cause acute altitude illnesses and is associated with impaired cognitive and physical performance.The most effective preventive strategies currently recommended include environmenta...Acute exposure to high altitude can cause acute altitude illnesses and is associated with impaired cognitive and physical performance.The most effective preventive strategies currently recommended include environmental acclimatization(slow ascent and/or pre-acclimatization)or pharmacological support of acclimatization using acetazolamide.However,these strategies are not practical for high-altitude exposures that require rapid and unplanned ascent,high physical and mental performance,such as rescue missions or military operations.Dexamethasone and other modulators of the glucocorticoid system take effect quickly and are effective alternatives for preventing acute altitude illnesses when rapidly ascending to high altitudes.As the efficacy of dexamethasone in preventing acute mountain illnesses remains controversial,a review of existing studies on the use of dexamethasone for the prevention of acute mountain sickness was conducted,aiming to determine the best strategy.Possible mechanisms of protection against acute altitude illnesses are discussed based on the results of clinical trials.The data indicate that dexamethasone is most effective at altitudes above 4000 m at doses of 8–16 mg/d.Appropriately designed and powered trials are needed to obtain more evidence-based results on the dosage and timing of dexamethasone administration,and to provide optimized recommendations for the application of this powerful pharmacological tool.展开更多
Kinetic impact is the most practical planetary-defense technique,with momentum-transfer efficiency central to deflection design.We present a Monte Carlo photometric framework that couples ejecta sampling,dynamical evo...Kinetic impact is the most practical planetary-defense technique,with momentum-transfer efficiency central to deflection design.We present a Monte Carlo photometric framework that couples ejecta sampling,dynamical evolution,and image synthesis to compare directly with HST,LICIACube,ground-based and Lucy observations of the DART impact.Decomposing ejecta into(1)a highvelocity(~1600 m/s)plume exhibiting Na/K resonance,(2)a low-velocity(~1 m/s)conical component shaped by binary gravity and solar radiation pressure,and(3)meter-scale boulders,we quantify each component’s mass and momentum.Fitting photometric decay curves and morphological evolution yields size-velocity distributions and,via scaling laws,estimates of Dimorphos’bulk density,cratering parameters,and cohesive strength that agree with dynamical constraints.Photometric ejecta modeling therefore provides a robust route to constrain momentum enhancement and target properties,improving predictive capability for kinetic-deflection missions.展开更多
Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biolo...Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biological nano-/micro-/meso-scale manufacturing provide complementary approaches to overcome key space exploration challenges by enabling the in-situ production of essential life-support materials,propellants,and other resources.This review examines the origin and historical evolution of space manufacturing and the latest advances across different environments—from orbital space stations and the lunar surface to Mars and asteroids.It is structured to present the current state of research,outline key manufacturing strategies and technologies,assess the technical and environmental challenges,and discuss emerging trends and future directions.Besides,the potential applications of emerging technologies such as synthetic biology and artificial intelligence in overcoming the limitations of microgravity,limited resources,and extreme conditions are discussed.Ultimately,this integrative review could serve to guide future development,from advancing space science and disruptive manufacturing to enabling interdisciplinary and application-level innovations.展开更多
A large-scale view of the magnetospheric cusp is expected to be obtained by the Soft X-ray Imager(SXI)onboard the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE).However,it is challenging to trace the three-d...A large-scale view of the magnetospheric cusp is expected to be obtained by the Soft X-ray Imager(SXI)onboard the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE).However,it is challenging to trace the three-dimensional cusp boundary from a two-dimensional X-ray image because the detected X-ray signals will be integrated along the line of sight.In this work,a global magnetohydrodynamic code was used to simulate the X-ray images and photon count images,assuming an interplanetary magnetic field with a pure Bz component.The assumption of an elliptic cusp boundary at a given altitude was used to trace the equatorward and poleward boundaries of the cusp from a simulated X-ray image.The average discrepancy was less than 0.1 RE.To reduce the influence of instrument effects and cosmic X-ray backgrounds,image denoising was considered before applying the method above to SXI photon count images.The cusp boundaries were reasonably reconstructed from the noisy X-ray image.展开更多
Targeting Chang'E-8 mission'in-situ resource utilization(ISRU)for sustainable lunar habitats,laser powder bed fusion(LPBF)provides a viable pathway for in-situ additive manufacturing of lunar regolith.To eluci...Targeting Chang'E-8 mission'in-situ resource utilization(ISRU)for sustainable lunar habitats,laser powder bed fusion(LPBF)provides a viable pathway for in-situ additive manufacturing of lunar regolith.To elucidate mission relevant mechanical behavior and failure mechanisms of LPBF fabricated lunar regolith simulants,mare type and highland type simulant specimens were produced.Microstructural characterization,mechanical test coupled with three-dimensional digital image correlation(3D-DIC),and an energy-dissipation framework were employed for comprehensive analysis.The pristine highland specimens achieved 5.79 MPa and a peak strain of 0.13(50 mm×50 mm×30 mm),significantly outperforming their mare counterparts.Wire-cutting to 20 mm×20 mm×20 mm lowered strength by~20%and peak strain to 0.04,indicating cutting-induced defects reduce ductility.All specimens displayed multipeaked stress–strain curves.3D-DIC revealed band-type strain localization in pristine highland samples,diffuse strain patterns in cut highland samples,and highly tortuous,network-type bands in mare samples;the anisotropy index was also quantified.Fragmented particles exhibited fractal dimensions ranging from 1.6 to 2.0(size 1.25–9 mm).Energy evolution progressed through three distinct stages:elastic energy storage,progressive energy dissipation delaying crack propagation,and final unstable collapse.An energy-based damage model was established and validated.The data and methods developed support Chang'E-8 missions'ISRU demonstrations and establish a transferable framework toward sustainable lunar habitats.展开更多
With the increasing number of geosynchronous orbit satellites with expiring lifetime,spacecraft refueling is crucial in enhancing the economic benefits of on-orbit services.The existing studies tend to be based on pre...With the increasing number of geosynchronous orbit satellites with expiring lifetime,spacecraft refueling is crucial in enhancing the economic benefits of on-orbit services.The existing studies tend to be based on predetermined refueling duration;however,the precise mission scheduling solution will be difficult to apply due to uncertain refueling duration caused by orbital transfer deviations and stochastic actuator faults during actual on-orbit service.Therefore,this paper proposes a robust mission scheduling strategy for geosynchronous orbit spacecraft on-orbit refueling missions with uncertain refueling duration.Firstly,a robust mission scheduling model is constructed by introducing the budget uncertainty set to describe the uncertain refueling duration.Secondly,a hybrid harris hawks optimization algorithm is designed to explore the optimal mission allocation and refueling sequences,which combines cubic chaotic mapping to initialize the population,and the crossover in the genetic algorithm is introduced to enhance global convergence.Finally,the typical simulation examples are constructed with real-mission scenarios in three aspects to analyze:performance comparisons with various algorithms;robustness analyses via comparisons of different on-orbit refueling durations;investigations into the impacts of different initial population strategies on algorithm performance,demonstrating the proposed mission scheduling framework's robustness and effectiveness by comparing it with the exact mission scheduling.展开更多
The Solar Close Observations and Proximity Experiments(SCOPE)mission will send a spacecraft into the solar atmosphere at a low altitude of just 5 R☉from the solar center.It aims to elucidate the mechanisms behind sol...The Solar Close Observations and Proximity Experiments(SCOPE)mission will send a spacecraft into the solar atmosphere at a low altitude of just 5 R☉from the solar center.It aims to elucidate the mechanisms behind solar eruptions and coronal heating,and to directly measure the coronal magnetic field.The mission will perform in situ measurements of the current sheet between coronal mass ejections and their associated solar flares,and energetic particles produced by either reconnection or fast-mode shocks driven by coronal mass ejections.This will help to resolve the nature of reconnections in current sheets,and energetic particle acceleration regions.To investigate coronal heating,the mission will observe nano-flares on scales smaller than 70 km in the solar corona and regions smaller than 40 km in the photosphere,where magnetohydrodynamic waves originate.To study solar wind acceleration mechanisms,the mission will also track the process of ion charge-state freezing in the solar wind.A key achievement will be the observation of the coronal magnetic field at unprecedented proximity to the solar photosphere.The polar regions will also be observed at close range,and the inner edge of the solar system dust disk may be identified for the first time.This work presents the detailed background,science,and mission concept of SCOPE and discusses how we aim to address the questions mentioned above.展开更多
To fulfill the training requirements for the daily operations of multirotor unmanned aerial vehicles(UAVs)clusters,a UAV cluster collaborative task integrated simulation platform(UAV-TISP)was developed.The platform in...To fulfill the training requirements for the daily operations of multirotor unmanned aerial vehicles(UAVs)clusters,a UAV cluster collaborative task integrated simulation platform(UAV-TISP)was developed.The platform integrates a suite of hardware and software to simulate a range of collaborative UAV cluster operation scenarios.It features modules for collaborative task planning,UAV cluster simulations,and tactical monitoring.The platform significantly reduces training costs by eliminating physical drone dependencies while offering a flexible environment for testing swarm algorithms.UAV-TISP supports both individual UAV and swarm operations,incorporating high-fidelity flight dynamics,real-time communication via user datagram protocol(UDP),and collision avoidance strategies.Utilizing the OSGEarth engine,it enables dynamic 3D environment visualization and scenario customization.Three key task scenarios-route flight,formation reconstruction,and formation transformation-were tested to validate the platform’s efficacy.Results demonstrated robust formation maintenance,adaptive collision avoidance,and seamless task execution.Comparative analysis with Gazebo Sim revealed lower trajectory deviations in UAV-TISP,highlighting its superior accuracy in simulating real-world flight dynamics.Future work will focus on enhancing scalability for diverse UAV models,optimizing swarm networking under communication constraints,and expanding mission scenarios.UAV-TISP serves as a versatile tool for both operational training and advanced algorithm development in UAV cluster applications.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
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 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
This paper comprehensively explores the impulsive on-orbit inspection game problem utilizing reinforcement learning and game training methods.The purpose of the spacecraft is to inspect the entire surface of a non-coo...This paper comprehensively explores the impulsive on-orbit inspection game problem utilizing reinforcement learning and game training methods.The purpose of the spacecraft is to inspect the entire surface of a non-cooperative target with active maneuverability in front lighting.First,the impulsive orbital game problem is formulated as a turn-based sequential game problem.Second,several typical relative orbit transfers are encapsulated into modules to construct a parameterized action space containing discrete modules and continuous parameters,and multi-pass deep Q-networks(MPDQN)algorithm is used to implement autonomous decision-making.Then,a curriculum learning method is used to gradually increase the difficulty of the training scenario.The backtracking proportional self-play training framework is used to enhance the agent’s ability to defeat inconsistent strategies by building a pool of opponents.The behavior variations of the agents during training indicate that the intelligent game system gradually evolves towards an equilibrium situation.The restraint relations between the agents show that the agents steadily improve the strategy.The influence of various factors on game results is tested.展开更多
In this study, we provide a detailed case study of the X-pattern of equatorial ionization anomaly(EIA) observed on the night of September 12, 2021 by the Global-scale Observations of the Limb and Disk(GOLD) mission. U...In this study, we provide a detailed case study of the X-pattern of equatorial ionization anomaly(EIA) observed on the night of September 12, 2021 by the Global-scale Observations of the Limb and Disk(GOLD) mission. Unlike most previous studies about the X-pattern observed under the severely disturbed background ionosphere, this event is observed under geomagnetically quiet and low solar activity conditions. GOLD's continuous observations reveal that the X-pattern intensity evolves with local time, while its center's longitude remains constant. The total electron content(TEC) data derived from the ground-based Global Navigation Satellite System(GNSS) network aligns well with GOLD observations in capturing the formation of the X-pattern, extending coverage to areas beyond GOLD's observational reach. Additionally, the ESA's Swarm mission show that both sides of the X-pattern can coincide with the occurrence of small-scale equatorial plasma bubbles(EPBs). To further analyze the possible drivers of the X-pattern, observations from the Ionospheric Connection Explorer(ICON) satellite were used. It shows that the latitudinal expansion(or width) between the EIA crests in two hemispheres is proportional(or inversely proportional) to the upward(or downward) plasma drift velocity, which suggests that the zonal electric field should have a notable influence on the formation of EIA X-pattern. Further simulations using the SAMI2 model support this mechanism, as the X-pattern of EIA is successfully reproduced by setting the vertical plasma drift to different values at different longitudes.展开更多
Objectives This study aimed to examine the role of the hidden curriculum in transmitting the educational mission and its impacts on nursing students’professional socialization.Methods This constructivist grounded the...Objectives This study aimed to examine the role of the hidden curriculum in transmitting the educational mission and its impacts on nursing students’professional socialization.Methods This constructivist grounded theory study involved twenty-six students and five faculty members from a century-old nursing school in Macao.Semi-structured interviews examined the factors influencing nursing students’choice of a specific nursing school and their general learning experiences in nursing studies.Open and focused coding was employed to develop categories and concepts that capture the nuances of how the hidden curriculum influences students’personal experiences,perceptions,and values related to developing their professional identities.The data analysis was guided by the“Community of Practice”model.Results The educational mission fostered a hidden curriculum that emphasized nurturing qualities and social responsibilities,creating a family-like learning environment that positively influenced the professional socialization of nursing students.Under the core theme of“becoming a family,”two sub-themes emerged:“student-peer interactions-fostering sisterly/brotherly learning partnerships”and“student-faculty interactions–faculty’s acting as parenting instructors.”While the hidden curriculum promoted a democratic and egalitarian learning atmosphere among student-peers,it simultaneously reinforced hierarchical power dynamics among senior-junior students and student-faculty relationships,mirroring the power-based interpersonal dynamics often found in traditional Chinese families.Conclusions Explicating the educational mission can help shape a hidden curriculum that benefits nursing students’professional socialization.Faculty members should reflect on the power inequalities reproduced by the hidden curriculum and establish appropriate boundaries in student-faculty relationships.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
As battlefield scale enlarges,cross-platform collaborative combat provides an appealing paradigm for modern warfare.Complicated constraints and vast solution space pose great challenge for reasonable and efficient mis...As battlefield scale enlarges,cross-platform collaborative combat provides an appealing paradigm for modern warfare.Complicated constraints and vast solution space pose great challenge for reasonable and efficient mission planning,where path planning and target assignment are tightly coupled.In this paper,we focus on UAV mission planning under carrier delivery mode(e.g.,by aircraft carrier,ground vehicle,or transport aircraft) and design a three-layer hierarchical solution framework.In the first layer,we simultaneously determine delivery points and target set division by clustering.To address the safety concerns of radar risk and UAV endurance,an improved density peak clustering algorithm is developed by constraint fusio n.In the second layer,mission planning within each cluster is viewed as a coope rative multiple-task assignment problem.A hybrid heuristic algorithm that integrates a voting-based heuristic solution generation strategy(VHSG) and a stochastic variable neighborhood search(SVNS),called VHSG-SVNS,is proposed for rapid solution.Based on the results of the first two layers,the third layer transforms carrier path planning into a multiple-vehicle routing problem with time window.The cost between any two nodes is calculated by the A~* algorithm,and the genetic algorithm is then implemented to determine the global route.Finally,a practical mission scenario containing 200 targets is used to validate the effectiveness of the designed framework,where three layers cooperate well with each other to generate satisfactory combat scheduling.Comparisons are made in each layer to highlight optimum-seeking capability and efficiency of the proposed algorithms.Works done in this paper provide a simple but efficient solution framework for cross-platform cooperative mission planning problems,and can be potentially extended to other applications such as post-disaster search and rescue,forest surveillance and firefighting,logistics pick and delivery,etc.展开更多
Editorial Message:Asia Laboratory Animal Day:Origin and Founding Mission—Paying Tribute to the Silent Contributors in Scientific Research In the journey of advancing human scientific progress and health well-being,la...Editorial Message:Asia Laboratory Animal Day:Origin and Founding Mission—Paying Tribute to the Silent Contributors in Scientific Research In the journey of advancing human scientific progress and health well-being,laboratory animals serve as indispensable silent contributors.To commemorate their contributions and advocate for welfare principles,the“Asia Laboratory Animal Day”was established.This initiative is the result of collaborative efforts among various laboratory animal organizations across Asia,forming a crucial link in connecting scientific research ethics and humanistic care throughout the continent.展开更多
基金supported by Swedish Research Council(Vetenskapsradet,2023-04962).
文摘Space exploration is significant for scientific innovation,resource utilization,and planetary security.Space exploration involves several systems including satellites,space suits,communication systems,and robotics,which have to function under harsh space conditions such as extreme temperatures(−270 to 1650℃),microgravity(10^(-6)g),unhealthy humidity(<20%RH or>60%RH),high atmospheric pressure(~1450 psi),and radiation(4000–5000 mSv).Conventional energy-harvesting technologies(solar cells,fuel cells,and nuclear energy),that are normally used to power these space systems have certain limitations(e.g.,sunlight dependence,weight,degradation,big size,high cost,low capacity,radioactivity,complexity,and low efficiency).The constraints in conventional energy resources have made it imperative to look for non-conventional yet efficient alternatives.A great potential for enhancing efficiency,sustainability,and mission duration in space exploration can be offered by integrating triboelectric nanogenerators(TENGs)with existing energy sources.Recently,the potential of TENG including energy harvesting(from vibrations/movements in satellites and spacecraft),self-powered sensing,and microgravity,for multiple applications in different space missions has been discussed.This review comprehensively covers the use of TENGs for various space applications,such as planetary exploration missions(Mars environment monitoring),manned space equipment,In-orbit robotic operations/collision monitoring,spacecraft’s design and structural health monitoring,Aeronautical systems,and conventional energy harvesting(solar and nuclear).This review also discusses the use of self-powered TENG sensors for deep space object perception.At the same time,this review compares TENGs with conventional energy harvesting technologies for space systems.Lastly,this review talks about energy harvesting in satellites,TENG-based satellite communication systems,and future practical implementation challenges(with possible solutions).
文摘Acute exposure to high altitude can cause acute altitude illnesses and is associated with impaired cognitive and physical performance.The most effective preventive strategies currently recommended include environmental acclimatization(slow ascent and/or pre-acclimatization)or pharmacological support of acclimatization using acetazolamide.However,these strategies are not practical for high-altitude exposures that require rapid and unplanned ascent,high physical and mental performance,such as rescue missions or military operations.Dexamethasone and other modulators of the glucocorticoid system take effect quickly and are effective alternatives for preventing acute altitude illnesses when rapidly ascending to high altitudes.As the efficacy of dexamethasone in preventing acute mountain illnesses remains controversial,a review of existing studies on the use of dexamethasone for the prevention of acute mountain sickness was conducted,aiming to determine the best strategy.Possible mechanisms of protection against acute altitude illnesses are discussed based on the results of clinical trials.The data indicate that dexamethasone is most effective at altitudes above 4000 m at doses of 8–16 mg/d.Appropriately designed and powered trials are needed to obtain more evidence-based results on the dosage and timing of dexamethasone administration,and to provide optimized recommendations for the application of this powerful pharmacological tool.
基金supported by the National Natural Science Foundation of China(Grant No.12272018)the National Key Basic Research Project(2022JCJQZD20600).
文摘Kinetic impact is the most practical planetary-defense technique,with momentum-transfer efficiency central to deflection design.We present a Monte Carlo photometric framework that couples ejecta sampling,dynamical evolution,and image synthesis to compare directly with HST,LICIACube,ground-based and Lucy observations of the DART impact.Decomposing ejecta into(1)a highvelocity(~1600 m/s)plume exhibiting Na/K resonance,(2)a low-velocity(~1 m/s)conical component shaped by binary gravity and solar radiation pressure,and(3)meter-scale boulders,we quantify each component’s mass and momentum.Fitting photometric decay curves and morphological evolution yields size-velocity distributions and,via scaling laws,estimates of Dimorphos’bulk density,cratering parameters,and cohesive strength that agree with dynamical constraints.Photometric ejecta modeling therefore provides a robust route to constrain momentum enhancement and target properties,improving predictive capability for kinetic-deflection missions.
基金supported by National Natural Science Foundation of China(22278241)a grant from the Institute Guo Qiang,Tsinghua University(2021GQG1016).
文摘Space exploration and manufacturing are of critical importance for scientific advancement,technological innovation,national security,and the acquisition of extraterrestrial resources.In view of this,chemical and biological nano-/micro-/meso-scale manufacturing provide complementary approaches to overcome key space exploration challenges by enabling the in-situ production of essential life-support materials,propellants,and other resources.This review examines the origin and historical evolution of space manufacturing and the latest advances across different environments—from orbital space stations and the lunar surface to Mars and asteroids.It is structured to present the current state of research,outline key manufacturing strategies and technologies,assess the technical and environmental challenges,and discuss emerging trends and future directions.Besides,the potential applications of emerging technologies such as synthetic biology and artificial intelligence in overcoming the limitations of microgravity,limited resources,and extreme conditions are discussed.Ultimately,this integrative review could serve to guide future development,from advancing space science and disruptive manufacturing to enabling interdisciplinary and application-level innovations.
基金funded by the National Natural Science Foundation of China(NNSFC)under Grant Numbers 42322408,42188101,and 42441809Additional support was provided by the Climbing Program of the National Space Science Center(NSSC,Grant No.E4PD3005)as well as the Specialized Research Fund for State Key Laboratories of China.
文摘A large-scale view of the magnetospheric cusp is expected to be obtained by the Soft X-ray Imager(SXI)onboard the Solar wind Magnetosphere Ionosphere Link Explorer(SMILE).However,it is challenging to trace the three-dimensional cusp boundary from a two-dimensional X-ray image because the detected X-ray signals will be integrated along the line of sight.In this work,a global magnetohydrodynamic code was used to simulate the X-ray images and photon count images,assuming an interplanetary magnetic field with a pure Bz component.The assumption of an elliptic cusp boundary at a given altitude was used to trace the equatorward and poleward boundaries of the cusp from a simulated X-ray image.The average discrepancy was less than 0.1 RE.To reduce the influence of instrument effects and cosmic X-ray backgrounds,image denoising was considered before applying the method above to SXI photon count images.The cusp boundaries were reasonably reconstructed from the noisy X-ray image.
基金supported by the Young Student Project of National Natural Science Foundation of China(No.525B2139)the National Key Research and Development Program of China(Nos.2023YFB3711300 and 2021YFF0500301)the Space Application System of China Manned Space Program(No.KJZ-YYWCL404)。
文摘Targeting Chang'E-8 mission'in-situ resource utilization(ISRU)for sustainable lunar habitats,laser powder bed fusion(LPBF)provides a viable pathway for in-situ additive manufacturing of lunar regolith.To elucidate mission relevant mechanical behavior and failure mechanisms of LPBF fabricated lunar regolith simulants,mare type and highland type simulant specimens were produced.Microstructural characterization,mechanical test coupled with three-dimensional digital image correlation(3D-DIC),and an energy-dissipation framework were employed for comprehensive analysis.The pristine highland specimens achieved 5.79 MPa and a peak strain of 0.13(50 mm×50 mm×30 mm),significantly outperforming their mare counterparts.Wire-cutting to 20 mm×20 mm×20 mm lowered strength by~20%and peak strain to 0.04,indicating cutting-induced defects reduce ductility.All specimens displayed multipeaked stress–strain curves.3D-DIC revealed band-type strain localization in pristine highland samples,diffuse strain patterns in cut highland samples,and highly tortuous,network-type bands in mare samples;the anisotropy index was also quantified.Fragmented particles exhibited fractal dimensions ranging from 1.6 to 2.0(size 1.25–9 mm).Energy evolution progressed through three distinct stages:elastic energy storage,progressive energy dissipation delaying crack propagation,and final unstable collapse.An energy-based damage model was established and validated.The data and methods developed support Chang'E-8 missions'ISRU demonstrations and establish a transferable framework toward sustainable lunar habitats.
基金co-supported by the National Natural Science Foundation of China(Nos.62473110,62403166)the Fundamental Research Funds for the Central Universities,China(No.2023FRFK02043)+1 种基金the Natural Science Foundation of Heilongjiang Province,China(No.LH2022F023)the National Key Laboratory of Space Intelligent Control Foundation,China(No.2023-JCJQ-LB-006-19)。
文摘With the increasing number of geosynchronous orbit satellites with expiring lifetime,spacecraft refueling is crucial in enhancing the economic benefits of on-orbit services.The existing studies tend to be based on predetermined refueling duration;however,the precise mission scheduling solution will be difficult to apply due to uncertain refueling duration caused by orbital transfer deviations and stochastic actuator faults during actual on-orbit service.Therefore,this paper proposes a robust mission scheduling strategy for geosynchronous orbit spacecraft on-orbit refueling missions with uncertain refueling duration.Firstly,a robust mission scheduling model is constructed by introducing the budget uncertainty set to describe the uncertain refueling duration.Secondly,a hybrid harris hawks optimization algorithm is designed to explore the optimal mission allocation and refueling sequences,which combines cubic chaotic mapping to initialize the population,and the crossover in the genetic algorithm is introduced to enhance global convergence.Finally,the typical simulation examples are constructed with real-mission scenarios in three aspects to analyze:performance comparisons with various algorithms;robustness analyses via comparisons of different on-orbit refueling durations;investigations into the impacts of different initial population strategies on algorithm performance,demonstrating the proposed mission scheduling framework's robustness and effectiveness by comparing it with the exact mission scheduling.
基金supported by the National Key R&D Program of China (2022YFF0503800)National Natural Science Foundation of China grants (12073073, 11933009, 12273107 and U2031141)+6 种基金grants associated with the Yunnan Revitalization Talent Support Programthe Foundation of the Chinese Academy of Sciences (Light of West China Program)the Yunling Scholar Project of Yunnan Provincethe Yunnan Province Scientist Workshop of Solar Physicsthe Applied Basic Research of Yunnan Province grants (202101AT070018 and 2019FB005)supported by the National Natural Science Foundation of China grants (12273107 and U2031141)the Yunnan Key Laboratory of Solar Physics and Space Science (202205AG070009)
文摘The Solar Close Observations and Proximity Experiments(SCOPE)mission will send a spacecraft into the solar atmosphere at a low altitude of just 5 R☉from the solar center.It aims to elucidate the mechanisms behind solar eruptions and coronal heating,and to directly measure the coronal magnetic field.The mission will perform in situ measurements of the current sheet between coronal mass ejections and their associated solar flares,and energetic particles produced by either reconnection or fast-mode shocks driven by coronal mass ejections.This will help to resolve the nature of reconnections in current sheets,and energetic particle acceleration regions.To investigate coronal heating,the mission will observe nano-flares on scales smaller than 70 km in the solar corona and regions smaller than 40 km in the photosphere,where magnetohydrodynamic waves originate.To study solar wind acceleration mechanisms,the mission will also track the process of ion charge-state freezing in the solar wind.A key achievement will be the observation of the coronal magnetic field at unprecedented proximity to the solar photosphere.The polar regions will also be observed at close range,and the inner edge of the solar system dust disk may be identified for the first time.This work presents the detailed background,science,and mission concept of SCOPE and discusses how we aim to address the questions mentioned above.
文摘To fulfill the training requirements for the daily operations of multirotor unmanned aerial vehicles(UAVs)clusters,a UAV cluster collaborative task integrated simulation platform(UAV-TISP)was developed.The platform integrates a suite of hardware and software to simulate a range of collaborative UAV cluster operation scenarios.It features modules for collaborative task planning,UAV cluster simulations,and tactical monitoring.The platform significantly reduces training costs by eliminating physical drone dependencies while offering a flexible environment for testing swarm algorithms.UAV-TISP supports both individual UAV and swarm operations,incorporating high-fidelity flight dynamics,real-time communication via user datagram protocol(UDP),and collision avoidance strategies.Utilizing the OSGEarth engine,it enables dynamic 3D environment visualization and scenario customization.Three key task scenarios-route flight,formation reconstruction,and formation transformation-were tested to validate the platform’s efficacy.Results demonstrated robust formation maintenance,adaptive collision avoidance,and seamless task execution.Comparative analysis with Gazebo Sim revealed lower trajectory deviations in UAV-TISP,highlighting its superior accuracy in simulating real-world flight dynamics.Future work will focus on enhancing scalability for diverse UAV models,optimizing swarm networking under communication constraints,and expanding mission scenarios.UAV-TISP serves as a versatile tool for both operational training and advanced algorithm development in UAV cluster applications.
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.
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.
文摘This paper comprehensively explores the impulsive on-orbit inspection game problem utilizing reinforcement learning and game training methods.The purpose of the spacecraft is to inspect the entire surface of a non-cooperative target with active maneuverability in front lighting.First,the impulsive orbital game problem is formulated as a turn-based sequential game problem.Second,several typical relative orbit transfers are encapsulated into modules to construct a parameterized action space containing discrete modules and continuous parameters,and multi-pass deep Q-networks(MPDQN)algorithm is used to implement autonomous decision-making.Then,a curriculum learning method is used to gradually increase the difficulty of the training scenario.The backtracking proportional self-play training framework is used to enhance the agent’s ability to defeat inconsistent strategies by building a pool of opponents.The behavior variations of the agents during training indicate that the intelligent game system gradually evolves towards an equilibrium situation.The restraint relations between the agents show that the agents steadily improve the strategy.The influence of various factors on game results is tested.
基金supported by the National Key R&D Program of China (Grant No. 2022YFF0503700)the special funds of Hubei Luojia Laboratory (220100011)+1 种基金Chao Xiong is supported by the ISSI-BJ project, “the electromagnetic data validation and scientific application research based on CSES satellite”ISSI/ISSI-BJ project “Multi-Scale Magnetosphere–Ionosphere–Thermosphere Interaction”。
文摘In this study, we provide a detailed case study of the X-pattern of equatorial ionization anomaly(EIA) observed on the night of September 12, 2021 by the Global-scale Observations of the Limb and Disk(GOLD) mission. Unlike most previous studies about the X-pattern observed under the severely disturbed background ionosphere, this event is observed under geomagnetically quiet and low solar activity conditions. GOLD's continuous observations reveal that the X-pattern intensity evolves with local time, while its center's longitude remains constant. The total electron content(TEC) data derived from the ground-based Global Navigation Satellite System(GNSS) network aligns well with GOLD observations in capturing the formation of the X-pattern, extending coverage to areas beyond GOLD's observational reach. Additionally, the ESA's Swarm mission show that both sides of the X-pattern can coincide with the occurrence of small-scale equatorial plasma bubbles(EPBs). To further analyze the possible drivers of the X-pattern, observations from the Ionospheric Connection Explorer(ICON) satellite were used. It shows that the latitudinal expansion(or width) between the EIA crests in two hemispheres is proportional(or inversely proportional) to the upward(or downward) plasma drift velocity, which suggests that the zonal electric field should have a notable influence on the formation of EIA X-pattern. Further simulations using the SAMI2 model support this mechanism, as the X-pattern of EIA is successfully reproduced by setting the vertical plasma drift to different values at different longitudes.
基金supported by Foundation of Macao(No.G-BXX-00047-2112367-03)。
文摘Objectives This study aimed to examine the role of the hidden curriculum in transmitting the educational mission and its impacts on nursing students’professional socialization.Methods This constructivist grounded theory study involved twenty-six students and five faculty members from a century-old nursing school in Macao.Semi-structured interviews examined the factors influencing nursing students’choice of a specific nursing school and their general learning experiences in nursing studies.Open and focused coding was employed to develop categories and concepts that capture the nuances of how the hidden curriculum influences students’personal experiences,perceptions,and values related to developing their professional identities.The data analysis was guided by the“Community of Practice”model.Results The educational mission fostered a hidden curriculum that emphasized nurturing qualities and social responsibilities,creating a family-like learning environment that positively influenced the professional socialization of nursing students.Under the core theme of“becoming a family,”two sub-themes emerged:“student-peer interactions-fostering sisterly/brotherly learning partnerships”and“student-faculty interactions–faculty’s acting as parenting instructors.”While the hidden curriculum promoted a democratic and egalitarian learning atmosphere among student-peers,it simultaneously reinforced hierarchical power dynamics among senior-junior students and student-faculty relationships,mirroring the power-based interpersonal dynamics often found in traditional Chinese families.Conclusions Explicating the educational mission can help shape a hidden curriculum that benefits nursing students’professional socialization.Faculty members should reflect on the power inequalities reproduced by the hidden curriculum and establish appropriate boundaries in student-faculty relationships.
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.
文摘As battlefield scale enlarges,cross-platform collaborative combat provides an appealing paradigm for modern warfare.Complicated constraints and vast solution space pose great challenge for reasonable and efficient mission planning,where path planning and target assignment are tightly coupled.In this paper,we focus on UAV mission planning under carrier delivery mode(e.g.,by aircraft carrier,ground vehicle,or transport aircraft) and design a three-layer hierarchical solution framework.In the first layer,we simultaneously determine delivery points and target set division by clustering.To address the safety concerns of radar risk and UAV endurance,an improved density peak clustering algorithm is developed by constraint fusio n.In the second layer,mission planning within each cluster is viewed as a coope rative multiple-task assignment problem.A hybrid heuristic algorithm that integrates a voting-based heuristic solution generation strategy(VHSG) and a stochastic variable neighborhood search(SVNS),called VHSG-SVNS,is proposed for rapid solution.Based on the results of the first two layers,the third layer transforms carrier path planning into a multiple-vehicle routing problem with time window.The cost between any two nodes is calculated by the A~* algorithm,and the genetic algorithm is then implemented to determine the global route.Finally,a practical mission scenario containing 200 targets is used to validate the effectiveness of the designed framework,where three layers cooperate well with each other to generate satisfactory combat scheduling.Comparisons are made in each layer to highlight optimum-seeking capability and efficiency of the proposed algorithms.Works done in this paper provide a simple but efficient solution framework for cross-platform cooperative mission planning problems,and can be potentially extended to other applications such as post-disaster search and rescue,forest surveillance and firefighting,logistics pick and delivery,etc.
文摘Editorial Message:Asia Laboratory Animal Day:Origin and Founding Mission—Paying Tribute to the Silent Contributors in Scientific Research In the journey of advancing human scientific progress and health well-being,laboratory animals serve as indispensable silent contributors.To commemorate their contributions and advocate for welfare principles,the“Asia Laboratory Animal Day”was established.This initiative is the result of collaborative efforts among various laboratory animal organizations across Asia,forming a crucial link in connecting scientific research ethics and humanistic care throughout the continent.
