Launch barge is an effective tool for transporting ship segments from one place to another in shipyards. During shifting of segments onto a barge, the slideway on the barge＇s deck must be adjusted to maintain the sam...Launch barge is an effective tool for transporting ship segments from one place to another in shipyards. During shifting of segments onto a barge, the slideway on the barge＇s deck must be adjusted to maintain the same level as the wharf and also the barge must be kept level by adjusting the water in the ballast tanks. When to open the adjusting valves is an important factor influencing the barge＇s trim during the water-adjustment process. Because these adjustments are complex a mathematical model was formulated,after analyzing the characteristics of the process of moving the segments onto the barges deck, and considering the effects of this movement＇s speed and variations in tidal levels during the move. Then the model was solved by the penalty function method, the grid method, and improved simulated annealing, respectively. The best optimization model and its corresponding solution were then determined. Finally, it was proven that the model and the method adopted are correct and suitable, by calculating and analysing an example.展开更多
The proliferation of carrier aircraft and the integration of unmanned aerial vehicles(UAVs)on aircraft carriers present new challenges to the automation of launch and recovery operations.This paper investigates a coll...The proliferation of carrier aircraft and the integration of unmanned aerial vehicles(UAVs)on aircraft carriers present new challenges to the automation of launch and recovery operations.This paper investigates a collaborative scheduling problem inherent to the operational processes of carrier aircraft,where launch and recovery tasks are conducted concurrently on the flight deck.The objective is to minimize the cumulative weighted waiting time in the air for recovering aircraft and the cumulative weighted delay time for launching aircraft.To tackle this challenge,a multiple population self-adaptive differential evolution(MPSADE)algorithm is proposed.This method features a self-adaptive parameter updating mechanism that is contingent upon population diversity,an asynchronous updating scheme,an individual migration operator,and a global crossover mechanism.Additionally,comprehensive experiments are conducted to validate the effectiveness of the proposed model and algorithm.Ultimately,a comparative analysis with existing operation modes confirms the enhanced efficiency of the collaborative operation mode.展开更多
The radiative heat flux of the plume from reusable rockets is a critical parameter during the launch and return processes.This paper proposes a method for calculating radiative heat flux with higher accuracy than prev...The radiative heat flux of the plume from reusable rockets is a critical parameter during the launch and return processes.This paper proposes a method for calculating radiative heat flux with higher accuracy than previously reported for a recoverable nine-engine liquid-propellant rocket.Based on the Radiative Transfer Equation(RTE),this study employs the discrete transfer method to solve the transient RTE problem using physical properties to describe the problem while avoiding the need to directly solve mathematical equations.The proposed method can effectively determine the radiative heat flux of the flow field and is applicable to problems involving various geometries.Calculations reveal that during the ascent phase of the rocket,the radiative heat flux at the base of the vehicle reaches its maximum in the initial stages of the lift-off,reaching a maximum of~50 kW/m^(2),which is 2.24 times the maximum value during the return phase.During the deceleration stage of re-entry into the atmosphere,the maximum radiative heat flux recorded on the sidewall of the rocket is 29.1 kW/m^(2);the maximum heat flux on the bottom surface is approximately 22.3 kW/m^(2),accounting for 76.6%of that on the rocket's sidewall.This provides a basis for the thermal protection design of the rocket's bottom and walls as well as for the thermal management of cryogenic propellant tanks.Future research will involve ground engine testing and flight experiments to further validate the proposed model.展开更多
On June 9,2025,CIIS held a launch event for its research report“Promoting Modernization Across Countries Through the Global Development Initiative.”The event was attended by CIIS President Chen Bo,Ambassador of Barb...On June 9,2025,CIIS held a launch event for its research report“Promoting Modernization Across Countries Through the Global Development Initiative.”The event was attended by CIIS President Chen Bo,Ambassador of Barbados to China Hallam Henry,Ambassador of Grenada to China Ma Yan,Ambassador of Timor-Leste to China Loro Horta,Ambassador of Bolivia to China Hugo Siles,Ambassador of Venezuela to China Remigio Ceballos Ichaso,Ambassador of Nepal to China Krishna Prasad Oli,Vice Director of the China Foreign Languages Publishing Administration and President of the Institute of Contemporary China and the World Yu Yunquan,Director of the Institute of International Strategy at Party School of the Central Committee(National Academy of Governance)Wu Zhicheng,and Vice Chairman of the National Global Strategy Think Tank at Chinese Academy of Social Sciences Wang Lei,all of whom delivered remarks at the launch.展开更多
In the era of global space industry’s rapid expansion,reusable launch technology has the advantage of cost reduction,but makes launch frequency and flight reliability remain critical.This study proposes that Artifici...In the era of global space industry’s rapid expansion,reusable launch technology has the advantage of cost reduction,but makes launch frequency and flight reliability remain critical.This study proposes that Artificial Intelligence(AI)would be the potential disruptive technology to solve these challenges.AI enables transformative capabilities for launch vehicles which are pointed out in four domains:Agile launch operations enabling automate testing,fault diagnosis,and decision-making for targeting hour-level launch cycles and minute-level fault resolution;high-reliability flight enabling real-time autonomous fault diagnosis,mission replanning,and fault-tolerant control within seconds during anomalies,potentially improving reliability by 1–2 orders of magnitude;rapid maintenance enabling real-time health monitoring and lifespan prediction for swift relaunch decisions;efficient space traffic management enabling predict/resolve orbital conflicts amid growing congestion from satellites and debris.The key challenges for AI applications are analyzed as well,including multi-system coupling,uncertain failure modes and narrow flight corridors,limited sensor data,and massive heterogeneous data processing.Finally,the study also proposes that AI promises substantial efficiency gains in launch vehicle design,manufacturing,and testing through multidisciplinary optimization and reduced reliance on physical testing.展开更多
High-altitude rescue is dangerous and difficult.A new rescue method is proposed here based on electromagnetically launched tethered nets.Four electromagnetic launching units are attached to a revolving platform,from w...High-altitude rescue is dangerous and difficult.A new rescue method is proposed here based on electromagnetically launched tethered nets.Four electromagnetic launching units are attached to a revolving platform,from which four projectiles are launched.The four projectiles are connected to a tethered net,bringing it into motion.As the tethered net approaches and comes into contact with the object,the object will be trapped,and the rescue task will then be completed as long as the tethered net can be restored along with the trapped object.The structural design of the electromagnetic launching unit is presented with the established mathematical model.The motion characteristics of the launched projectiles are studied and their exit velocities are modeled and measured.Terminal velocities of these projectiles are characterized,and the final shape and position of the projected tethered net are obtained.This study validates the feasibility of using electromagnetically launched tethered nets to perform high-altitude rescues.展开更多
As the performance of the box-type multiple launch rocket system(BMLRS)improves,its mechanical structures,particularly the plane clearance design between the slider on the rocket and the guide inside the launch canist...As the performance of the box-type multiple launch rocket system(BMLRS)improves,its mechanical structures,particularly the plane clearance design between the slider on the rocket and the guide inside the launch canister,have grown increasingly complex.However,deficiencies still exist in the current launch modeling theory for BMLRS.In this study,a multi-rigid-flexible-body launch dynamics model coupling the launch platform and rocket was established using the multibody system transfer matrix method and the Newton-Euler formulation.Furthermore,considering the bending of the launch canister,a detection algorithm for slider-guide plane clearance contact was proposed.To quantify the contact force and friction effect between the slider and guide,the contact force model and modified Coulomb model were introduced.Both the modal and launch tests were conducted.Additionally,the modal convergence was verified.By comparing the modal experiments and simulation results,the maximum relative error of the eigenfrequency is 3.29%.thereby verifying the accuracy of the developed BMLRS dynamics model.Furthermore,the launch test validated the proposed plane clearance contact model.Moreover,the study investigated the influence of various model parameters on the dynamic characteristics of BMLRS,including launch canister bending stiffness,slider and guide material,slider-guide clearance,slider length and layout.This analysis of influencing factors provides a foundation for future optimization in BMLRS design.展开更多
Sea-based rocket launches encounter significant challenges stemming from dynamic marine environmental interactions.During the hot launch phase,characterized by low-velocity ascent,the departure of the rocket from the ...Sea-based rocket launches encounter significant challenges stemming from dynamic marine environmental interactions.During the hot launch phase,characterized by low-velocity ascent,the departure of the rocket from the oscillatory platform exhibits heightened sensitivity to external disturbances.In the development stage,assessing the launch dynamics and the clearance between the rocket and framed launcher are crucial for improving the reliability of sea-based rocket launches in rough sea conditions.This study presents a high-fidelity dynamic model of maritime hot launch system,demonstrating 3.21%prediction error through rigorous validation against experimental datasets from comprehensive modal analyses and the full-scale rocket flight test.To mitigate collision risks,we develop a computational method employing spatial vector analysis for dynamic measurement of rocket-launcher clearance during departure.Systematic investigations reveal that in rough sea conditions,optimal departure dynamics are achieved at θ_(thrust)=270°nozzle azimuth configuration,reducing failure probability compared to conventional orientations.The developed assessment framework not only resolves critical safety challenges in current sea launch systems but also establishes foundational principles for optimizing adapter axial configuration patterns in future designs.展开更多
The research on optimization methods for constellation launch deployment strategies focused on the consideration of mission interval time constraints at the launch site.Firstly,a dynamic modeling of the constellation ...The research on optimization methods for constellation launch deployment strategies focused on the consideration of mission interval time constraints at the launch site.Firstly,a dynamic modeling of the constellation deployment process was established,and the relationship between the deployment window and the phase difference of the orbit insertion point,as well as the cost of phase adjustment after orbit insertion,was derived.Then,the combination of the constellation deployment position sequence was treated as a parameter,together with the sequence of satellite deployment intervals,as optimization variables,simplifying a highdimensional search problem within a wide range of dates to a finite-dimensional integer programming problem.An improved genetic algorithm with local search on deployment dates was introduced to optimize the launch deployment strategy.With the new description of the optimization variables,the total number of elements in the solution space was reduced by N orders of magnitude.Numerical simulation confirms that the proposed optimization method accelerates the convergence speed from hours to minutes.展开更多
Underwater launch is a transient vibration process under the impact load.The hydrodynamic calculation is an important part of equipment research.In this paper,firstly,combining the theory of the Euler-Bernoulli beam a...Underwater launch is a transient vibration process under the impact load.The hydrodynamic calculation is an important part of equipment research.In this paper,firstly,combining the theory of the Euler-Bernoulli beam and the potential flow,the transfer equation of the Euler-Bernoulli beam considering the hydroelastic effect is derived,which expands the application scope of the transfer matrix.The correctness of the transfer matrix for the beam with hydroelastic behaviors is verified by comparison with the results of the finite element analysis.Then the dynamics model of the underwater launch system is established based on the multibody system transfer matrix method,and the beam with hydroelastic behaviors is employed as the external vehicle.Subsequently,the overall transfer and dynamic equation are derived,resulting in the solution of the wet natural frequency and the dynamic response under the impact load.The comparison with experimental data validates the dynamics model and simulation results and ensures its reliability in practical applications.The dynamic of the system demonstrates that the launching interval and adjacent tube effect will exert an influence on the subsequent emission.This research provides a fast and efficient method for the dynamic calculation of the underwater launch system.展开更多
On January 15,2025,the China Road and Bridge Corporation(CRBC)Kenya Office and Africa Star Railway Operation Company Limited(Afristar),in collaboration with the Dream Building Service Association(DBSA),held the launch...On January 15,2025,the China Road and Bridge Corporation(CRBC)Kenya Office and Africa Star Railway Operation Company Limited(Afristar),in collaboration with the Dream Building Service Association(DBSA),held the launching ceremony for the International Free Lunch Programme at a school in the Mathare slum community of Nairobi.展开更多
On August 20,the Xi Jinping Thought on Diplomacy Studies Center held a book launch event“Hand in Hand,Heart to Heart-Toward a Shared Future”for Stories of the SCO in the New Era in Beijing.China's Assistant Mini...On August 20,the Xi Jinping Thought on Diplomacy Studies Center held a book launch event“Hand in Hand,Heart to Heart-Toward a Shared Future”for Stories of the SCO in the New Era in Beijing.China's Assistant Minister of Foreign Affairs Liu Bin and Deputy Secretary-General of the Shanghai Cooperation Organization(SCO)Ahmad Saidmurodzoda delivered speeches at the event,which was also attended by Zhang Deguang,China's former Vice Foreign Minister and the SCO's inaugural Secretary-General.展开更多
With the aid of multi-agent based modeling approach to complex systems, the hierarchy simulation models of carrier-based aircraft catapult launch are developed. Ocean, carrier, aircraft, and atmosphere are treated as ...With the aid of multi-agent based modeling approach to complex systems, the hierarchy simulation models of carrier-based aircraft catapult launch are developed. Ocean, carrier, aircraft, and atmosphere are treated as aggregation agents, the detailed components like catapult, landing gears, and disturbances are considered as meta-agents, which belong to their aggregation agent. Thus, the model with two layers is formed i.e. the aggregation agent layer and the meta-agent layer. The information communication among all agents is described. The meta-agents within one aggregation agent communicate with each other directly by information sharing, but the meta-agents, which belong to different aggregation agents exchange their information through the aggregation layer first, and then perceive it from the sharing environment, that is the aggregation agent. Thus, not only the hierarchy model is built, but also the environment perceived by each agent is specified. Meanwhile, the problem of balancing the independency of agent and the resource consumption brought by real-time communication within multi-agent system （MAS） is resolved. Each agent involved in carrier-based aircraft catapult launch is depicted, with considering the interaction within disturbed atmospheric environment and multiple motion bodies including carrier, aircraft, and landing gears. The models of reactive agents among them are derived based on tensors, and the perceived messages and inner frameworks of each agent are characterized. Finally, some results of a simulation instance are given. The simulation and modeling of dynamic system based on multi-agent system is of benefit to express physical concepts and logical hierarchy clearly and precisely. The system model can easily draw in kinds of other agents to achieve a precise simulation of more complex system. This modeling technique makes the complex integral dynamic equations of multibodies decompose into parallel operations of single agent, and it is convenient to expand, maintain, and reuse the program codes.展开更多
The feasibility of providing the tank a limited anti helicopter ability with gun launched missile is studied. A type of simulation model of gun launched missile against attack helicopters is established. The simula...The feasibility of providing the tank a limited anti helicopter ability with gun launched missile is studied. A type of simulation model of gun launched missile against attack helicopters is established. The simulation and the parameter optimization of missile control system under various circumstances are done. The gun launched missile can directly hit the helicopters in the typical tracks, all the missdistances are less than 1?m and the maximum overload is less than available overload. Gun launched missile is a feasible choice for tanks against attack helicopters.展开更多
At 11:00 p.m. on January 13, 2026, floodlights illuminated the launch pad at the Hainan Commercial Space Launch Site in Wenchang,south China’s Hainan Province. A Long March-8A (CZ-8A) carrier rocket lifted off with a...At 11:00 p.m. on January 13, 2026, floodlights illuminated the launch pad at the Hainan Commercial Space Launch Site in Wenchang,south China’s Hainan Province. A Long March-8A (CZ-8A) carrier rocket lifted off with a steady roar, its exhaust lighting up the night sky as it delivered a satellite into its designated orbit.The development of China’s first commercial space launch site has been striking. Since its inaugural launch in2024, it has completed 11 missions in less than 14 months—each a success.展开更多
Rwanda-China alliance launches youth innovation union,opening doors for African entrepreneurs On a warm afternoon in Kigali,students filled a conference hall at the University of Rwanda,sitting shoulder to shoulder wi...Rwanda-China alliance launches youth innovation union,opening doors for African entrepreneurs On a warm afternoon in Kigali,students filled a conference hall at the University of Rwanda,sitting shoulder to shoulder with lecturers and visitors from China,unsure at first how significant the moment would be.Some came out of curiosity.Others came with hope.By the end of the ceremony,many felt they had witnessed more than the launch of a new academic centre-they had watched a door open.展开更多
Over the past months,a southern Chinese harbor serving as a pivotal gateway to regions around the world has come into the spotlight after the launching of special customs operations on Hainan Island.LOCATED on the nor...Over the past months,a southern Chinese harbor serving as a pivotal gateway to regions around the world has come into the spotlight after the launching of special customs operations on Hainan Island.LOCATED on the northwest tip of HainanIsland,the Yangpu Port is a scene ofbustling activity with towering gantrycranes busily loading containers on andoff large cargo vessels.Port orders here have surgedas a result of a slew of special customs policiesthat went into force last December.展开更多
Preferential policies,efficient government,and a favorable geographical location...a multitude of factors make the Hainan FTP a promising land for businesses.SOON after the Hainan Free Trade Port(FTP)launched special ...Preferential policies,efficient government,and a favorable geographical location...a multitude of factors make the Hainan FTP a promising land for businesses.SOON after the Hainan Free Trade Port(FTP)launched special customs operations at the end of 2025,private enterprises operating at its Yangpu Port began to benefit substantially from the favorable policies and surging growth momentum in the region.While riding on an ocean of opportunities opened by the FTP,local businesses are bringing the island to a new level of prosperity,and thriving together with it as a community of shared future.展开更多
The relative characteristics of motion of the fuel and shell upon launching is analyzed. By means of mechanical analysis and calculation, it is proposed that relative motion exists not only in the ranges between the f...The relative characteristics of motion of the fuel and shell upon launching is analyzed. By means of mechanical analysis and calculation, it is proposed that relative motion exists not only in the ranges between the fuel and shell of the warhead, but also in the fuel in different positions. The result of study indicates that the position of the fuel in the warhead has a marked influence on the relative motion, while the frictional coefficient between the fuel and shell has less influence upon it.展开更多
Compared with the conventionally gaseous or liquid working media,the specific internal energy of supercritical carbon dioxide(SCD)is higher at the same temperature and pressure,and the critical temperature of carbon d...Compared with the conventionally gaseous or liquid working media,the specific internal energy of supercritical carbon dioxide(SCD)is higher at the same temperature and pressure,and the critical temperature of carbon dioxide is close to room temperature,making SCD a potential new working medium for pneumatic launch.To analyze the feasibility of this conception,an analytical model of a pneumatic catapult is established on basis of the conservations of mass and energy.The model consists of a high-pressure chamber and a low-pressure chamber connected by multiple valves,and there is a movable piston in the low-pressure chamber that can push an aircraft to accelerate.The effects of the launch readiness state of SCD in the high-pressure chamber,the initial volume of the low-pressure chamber and the valve control on the movement of the aircraft are analyzed.It is found that there is a restrictive relation between the temperature and pressure of the launch readiness state of SCD,i.e.,there is a maximum allowable launch readiness pressure when the launch readiness temperature is fixed.If this restrictive relation is not satisfied,the working medium in the low-pressure chamber will drop to its triple point within a few milliseconds,leading to a launch failure.Owing to this restrictive relation,there is an optimal launch readiness state of SCD with the highest working capacity for any allowable launch readiness temperature.The pressure of the low-pressure chamber will decrease significantly as the initial volume increases,leading to a decreased acceleration of the aircraft.The acceleration can be controlled below a critical value by a designed sequential blasting technique of multiple valves.The calculated results show that a 500 kg aircraft can be accelerated from 0 to 58 m/s in 0.9 s with 36 kg of carbon dioxide.This research provides a new technique for the controllable cold launch of an aircraft.展开更多
文摘Launch barge is an effective tool for transporting ship segments from one place to another in shipyards. During shifting of segments onto a barge, the slideway on the barge＇s deck must be adjusted to maintain the same level as the wharf and also the barge must be kept level by adjusting the water in the ballast tanks. When to open the adjusting valves is an important factor influencing the barge＇s trim during the water-adjustment process. Because these adjustments are complex a mathematical model was formulated,after analyzing the characteristics of the process of moving the segments onto the barges deck, and considering the effects of this movement＇s speed and variations in tidal levels during the move. Then the model was solved by the penalty function method, the grid method, and improved simulated annealing, respectively. The best optimization model and its corresponding solution were then determined. Finally, it was proven that the model and the method adopted are correct and suitable, by calculating and analysing an example.
文摘The proliferation of carrier aircraft and the integration of unmanned aerial vehicles(UAVs)on aircraft carriers present new challenges to the automation of launch and recovery operations.This paper investigates a collaborative scheduling problem inherent to the operational processes of carrier aircraft,where launch and recovery tasks are conducted concurrently on the flight deck.The objective is to minimize the cumulative weighted waiting time in the air for recovering aircraft and the cumulative weighted delay time for launching aircraft.To tackle this challenge,a multiple population self-adaptive differential evolution(MPSADE)algorithm is proposed.This method features a self-adaptive parameter updating mechanism that is contingent upon population diversity,an asynchronous updating scheme,an individual migration operator,and a global crossover mechanism.Additionally,comprehensive experiments are conducted to validate the effectiveness of the proposed model and algorithm.Ultimately,a comparative analysis with existing operation modes confirms the enhanced efficiency of the collaborative operation mode.
文摘The radiative heat flux of the plume from reusable rockets is a critical parameter during the launch and return processes.This paper proposes a method for calculating radiative heat flux with higher accuracy than previously reported for a recoverable nine-engine liquid-propellant rocket.Based on the Radiative Transfer Equation(RTE),this study employs the discrete transfer method to solve the transient RTE problem using physical properties to describe the problem while avoiding the need to directly solve mathematical equations.The proposed method can effectively determine the radiative heat flux of the flow field and is applicable to problems involving various geometries.Calculations reveal that during the ascent phase of the rocket,the radiative heat flux at the base of the vehicle reaches its maximum in the initial stages of the lift-off,reaching a maximum of~50 kW/m^(2),which is 2.24 times the maximum value during the return phase.During the deceleration stage of re-entry into the atmosphere,the maximum radiative heat flux recorded on the sidewall of the rocket is 29.1 kW/m^(2);the maximum heat flux on the bottom surface is approximately 22.3 kW/m^(2),accounting for 76.6%of that on the rocket's sidewall.This provides a basis for the thermal protection design of the rocket's bottom and walls as well as for the thermal management of cryogenic propellant tanks.Future research will involve ground engine testing and flight experiments to further validate the proposed model.
文摘On June 9,2025,CIIS held a launch event for its research report“Promoting Modernization Across Countries Through the Global Development Initiative.”The event was attended by CIIS President Chen Bo,Ambassador of Barbados to China Hallam Henry,Ambassador of Grenada to China Ma Yan,Ambassador of Timor-Leste to China Loro Horta,Ambassador of Bolivia to China Hugo Siles,Ambassador of Venezuela to China Remigio Ceballos Ichaso,Ambassador of Nepal to China Krishna Prasad Oli,Vice Director of the China Foreign Languages Publishing Administration and President of the Institute of Contemporary China and the World Yu Yunquan,Director of the Institute of International Strategy at Party School of the Central Committee(National Academy of Governance)Wu Zhicheng,and Vice Chairman of the National Global Strategy Think Tank at Chinese Academy of Social Sciences Wang Lei,all of whom delivered remarks at the launch.
基金supported by the National Natural Science Foundation of China(Nos.52495000 and 52332012).
文摘In the era of global space industry’s rapid expansion,reusable launch technology has the advantage of cost reduction,but makes launch frequency and flight reliability remain critical.This study proposes that Artificial Intelligence(AI)would be the potential disruptive technology to solve these challenges.AI enables transformative capabilities for launch vehicles which are pointed out in four domains:Agile launch operations enabling automate testing,fault diagnosis,and decision-making for targeting hour-level launch cycles and minute-level fault resolution;high-reliability flight enabling real-time autonomous fault diagnosis,mission replanning,and fault-tolerant control within seconds during anomalies,potentially improving reliability by 1–2 orders of magnitude;rapid maintenance enabling real-time health monitoring and lifespan prediction for swift relaunch decisions;efficient space traffic management enabling predict/resolve orbital conflicts amid growing congestion from satellites and debris.The key challenges for AI applications are analyzed as well,including multi-system coupling,uncertain failure modes and narrow flight corridors,limited sensor data,and massive heterogeneous data processing.Finally,the study also proposes that AI promises substantial efficiency gains in launch vehicle design,manufacturing,and testing through multidisciplinary optimization and reduced reliance on physical testing.
基金Zhejiang Provincial Natural Science Foundation of China(No.LY22E050013)China Postdoctoral Science Foundation(No.2021M690545)National Natural Science Foundation of China(No.51805124).
文摘High-altitude rescue is dangerous and difficult.A new rescue method is proposed here based on electromagnetically launched tethered nets.Four electromagnetic launching units are attached to a revolving platform,from which four projectiles are launched.The four projectiles are connected to a tethered net,bringing it into motion.As the tethered net approaches and comes into contact with the object,the object will be trapped,and the rescue task will then be completed as long as the tethered net can be restored along with the trapped object.The structural design of the electromagnetic launching unit is presented with the established mathematical model.The motion characteristics of the launched projectiles are studied and their exit velocities are modeled and measured.Terminal velocities of these projectiles are characterized,and the final shape and position of the projected tethered net are obtained.This study validates the feasibility of using electromagnetically launched tethered nets to perform high-altitude rescues.
基金supported by National Natural Science Foundation of China(Grant No.92266201).
文摘As the performance of the box-type multiple launch rocket system(BMLRS)improves,its mechanical structures,particularly the plane clearance design between the slider on the rocket and the guide inside the launch canister,have grown increasingly complex.However,deficiencies still exist in the current launch modeling theory for BMLRS.In this study,a multi-rigid-flexible-body launch dynamics model coupling the launch platform and rocket was established using the multibody system transfer matrix method and the Newton-Euler formulation.Furthermore,considering the bending of the launch canister,a detection algorithm for slider-guide plane clearance contact was proposed.To quantify the contact force and friction effect between the slider and guide,the contact force model and modified Coulomb model were introduced.Both the modal and launch tests were conducted.Additionally,the modal convergence was verified.By comparing the modal experiments and simulation results,the maximum relative error of the eigenfrequency is 3.29%.thereby verifying the accuracy of the developed BMLRS dynamics model.Furthermore,the launch test validated the proposed plane clearance contact model.Moreover,the study investigated the influence of various model parameters on the dynamic characteristics of BMLRS,including launch canister bending stiffness,slider and guide material,slider-guide clearance,slider length and layout.This analysis of influencing factors provides a foundation for future optimization in BMLRS design.
基金the experimental technology support provided by the China Academy of Launch Vehicle Technology
文摘Sea-based rocket launches encounter significant challenges stemming from dynamic marine environmental interactions.During the hot launch phase,characterized by low-velocity ascent,the departure of the rocket from the oscillatory platform exhibits heightened sensitivity to external disturbances.In the development stage,assessing the launch dynamics and the clearance between the rocket and framed launcher are crucial for improving the reliability of sea-based rocket launches in rough sea conditions.This study presents a high-fidelity dynamic model of maritime hot launch system,demonstrating 3.21%prediction error through rigorous validation against experimental datasets from comprehensive modal analyses and the full-scale rocket flight test.To mitigate collision risks,we develop a computational method employing spatial vector analysis for dynamic measurement of rocket-launcher clearance during departure.Systematic investigations reveal that in rough sea conditions,optimal departure dynamics are achieved at θ_(thrust)=270°nozzle azimuth configuration,reducing failure probability compared to conventional orientations.The developed assessment framework not only resolves critical safety challenges in current sea launch systems but also establishes foundational principles for optimizing adapter axial configuration patterns in future designs.
文摘The research on optimization methods for constellation launch deployment strategies focused on the consideration of mission interval time constraints at the launch site.Firstly,a dynamic modeling of the constellation deployment process was established,and the relationship between the deployment window and the phase difference of the orbit insertion point,as well as the cost of phase adjustment after orbit insertion,was derived.Then,the combination of the constellation deployment position sequence was treated as a parameter,together with the sequence of satellite deployment intervals,as optimization variables,simplifying a highdimensional search problem within a wide range of dates to a finite-dimensional integer programming problem.An improved genetic algorithm with local search on deployment dates was introduced to optimize the launch deployment strategy.With the new description of the optimization variables,the total number of elements in the solution space was reduced by N orders of magnitude.Numerical simulation confirms that the proposed optimization method accelerates the convergence speed from hours to minutes.
基金supported by the National Natural Science Foundation of China(Grant No.92266201).
文摘Underwater launch is a transient vibration process under the impact load.The hydrodynamic calculation is an important part of equipment research.In this paper,firstly,combining the theory of the Euler-Bernoulli beam and the potential flow,the transfer equation of the Euler-Bernoulli beam considering the hydroelastic effect is derived,which expands the application scope of the transfer matrix.The correctness of the transfer matrix for the beam with hydroelastic behaviors is verified by comparison with the results of the finite element analysis.Then the dynamics model of the underwater launch system is established based on the multibody system transfer matrix method,and the beam with hydroelastic behaviors is employed as the external vehicle.Subsequently,the overall transfer and dynamic equation are derived,resulting in the solution of the wet natural frequency and the dynamic response under the impact load.The comparison with experimental data validates the dynamics model and simulation results and ensures its reliability in practical applications.The dynamic of the system demonstrates that the launching interval and adjacent tube effect will exert an influence on the subsequent emission.This research provides a fast and efficient method for the dynamic calculation of the underwater launch system.
文摘On January 15,2025,the China Road and Bridge Corporation(CRBC)Kenya Office and Africa Star Railway Operation Company Limited(Afristar),in collaboration with the Dream Building Service Association(DBSA),held the launching ceremony for the International Free Lunch Programme at a school in the Mathare slum community of Nairobi.
文摘On August 20,the Xi Jinping Thought on Diplomacy Studies Center held a book launch event“Hand in Hand,Heart to Heart-Toward a Shared Future”for Stories of the SCO in the New Era in Beijing.China's Assistant Minister of Foreign Affairs Liu Bin and Deputy Secretary-General of the Shanghai Cooperation Organization(SCO)Ahmad Saidmurodzoda delivered speeches at the event,which was also attended by Zhang Deguang,China's former Vice Foreign Minister and the SCO's inaugural Secretary-General.
基金Aeronautical Science Foundation of China (2006ZA51004)
文摘With the aid of multi-agent based modeling approach to complex systems, the hierarchy simulation models of carrier-based aircraft catapult launch are developed. Ocean, carrier, aircraft, and atmosphere are treated as aggregation agents, the detailed components like catapult, landing gears, and disturbances are considered as meta-agents, which belong to their aggregation agent. Thus, the model with two layers is formed i.e. the aggregation agent layer and the meta-agent layer. The information communication among all agents is described. The meta-agents within one aggregation agent communicate with each other directly by information sharing, but the meta-agents, which belong to different aggregation agents exchange their information through the aggregation layer first, and then perceive it from the sharing environment, that is the aggregation agent. Thus, not only the hierarchy model is built, but also the environment perceived by each agent is specified. Meanwhile, the problem of balancing the independency of agent and the resource consumption brought by real-time communication within multi-agent system （MAS） is resolved. Each agent involved in carrier-based aircraft catapult launch is depicted, with considering the interaction within disturbed atmospheric environment and multiple motion bodies including carrier, aircraft, and landing gears. The models of reactive agents among them are derived based on tensors, and the perceived messages and inner frameworks of each agent are characterized. Finally, some results of a simulation instance are given. The simulation and modeling of dynamic system based on multi-agent system is of benefit to express physical concepts and logical hierarchy clearly and precisely. The system model can easily draw in kinds of other agents to achieve a precise simulation of more complex system. This modeling technique makes the complex integral dynamic equations of multibodies decompose into parallel operations of single agent, and it is convenient to expand, maintain, and reuse the program codes.
文摘The feasibility of providing the tank a limited anti helicopter ability with gun launched missile is studied. A type of simulation model of gun launched missile against attack helicopters is established. The simulation and the parameter optimization of missile control system under various circumstances are done. The gun launched missile can directly hit the helicopters in the typical tracks, all the missdistances are less than 1?m and the maximum overload is less than available overload. Gun launched missile is a feasible choice for tanks against attack helicopters.
文摘At 11:00 p.m. on January 13, 2026, floodlights illuminated the launch pad at the Hainan Commercial Space Launch Site in Wenchang,south China’s Hainan Province. A Long March-8A (CZ-8A) carrier rocket lifted off with a steady roar, its exhaust lighting up the night sky as it delivered a satellite into its designated orbit.The development of China’s first commercial space launch site has been striking. Since its inaugural launch in2024, it has completed 11 missions in less than 14 months—each a success.
文摘Rwanda-China alliance launches youth innovation union,opening doors for African entrepreneurs On a warm afternoon in Kigali,students filled a conference hall at the University of Rwanda,sitting shoulder to shoulder with lecturers and visitors from China,unsure at first how significant the moment would be.Some came out of curiosity.Others came with hope.By the end of the ceremony,many felt they had witnessed more than the launch of a new academic centre-they had watched a door open.
文摘Over the past months,a southern Chinese harbor serving as a pivotal gateway to regions around the world has come into the spotlight after the launching of special customs operations on Hainan Island.LOCATED on the northwest tip of HainanIsland,the Yangpu Port is a scene ofbustling activity with towering gantrycranes busily loading containers on andoff large cargo vessels.Port orders here have surgedas a result of a slew of special customs policiesthat went into force last December.
文摘Preferential policies,efficient government,and a favorable geographical location...a multitude of factors make the Hainan FTP a promising land for businesses.SOON after the Hainan Free Trade Port(FTP)launched special customs operations at the end of 2025,private enterprises operating at its Yangpu Port began to benefit substantially from the favorable policies and surging growth momentum in the region.While riding on an ocean of opportunities opened by the FTP,local businesses are bringing the island to a new level of prosperity,and thriving together with it as a community of shared future.
文摘The relative characteristics of motion of the fuel and shell upon launching is analyzed. By means of mechanical analysis and calculation, it is proposed that relative motion exists not only in the ranges between the fuel and shell of the warhead, but also in the fuel in different positions. The result of study indicates that the position of the fuel in the warhead has a marked influence on the relative motion, while the frictional coefficient between the fuel and shell has less influence upon it.
基金This work was funded by the National Natural Science Foundation of China(No.51576188).
文摘Compared with the conventionally gaseous or liquid working media,the specific internal energy of supercritical carbon dioxide(SCD)is higher at the same temperature and pressure,and the critical temperature of carbon dioxide is close to room temperature,making SCD a potential new working medium for pneumatic launch.To analyze the feasibility of this conception,an analytical model of a pneumatic catapult is established on basis of the conservations of mass and energy.The model consists of a high-pressure chamber and a low-pressure chamber connected by multiple valves,and there is a movable piston in the low-pressure chamber that can push an aircraft to accelerate.The effects of the launch readiness state of SCD in the high-pressure chamber,the initial volume of the low-pressure chamber and the valve control on the movement of the aircraft are analyzed.It is found that there is a restrictive relation between the temperature and pressure of the launch readiness state of SCD,i.e.,there is a maximum allowable launch readiness pressure when the launch readiness temperature is fixed.If this restrictive relation is not satisfied,the working medium in the low-pressure chamber will drop to its triple point within a few milliseconds,leading to a launch failure.Owing to this restrictive relation,there is an optimal launch readiness state of SCD with the highest working capacity for any allowable launch readiness temperature.The pressure of the low-pressure chamber will decrease significantly as the initial volume increases,leading to a decreased acceleration of the aircraft.The acceleration can be controlled below a critical value by a designed sequential blasting technique of multiple valves.The calculated results show that a 500 kg aircraft can be accelerated from 0 to 58 m/s in 0.9 s with 36 kg of carbon dioxide.This research provides a new technique for the controllable cold launch of an aircraft.
