The near-field blast wave characteristics(0.06m/kg^1/3<Z<1m/kg^1/3)of typical charge structures(sphere and cylinder)are investigated for supporting the protection of sympathetic detonation through near-field explosion experiment and numerical simulation.The load of near-field blast wave of cylindrical charge is experimentaly investigated,and a numerical caculation model of near-field explosion is established,The near-field blast wave structures and spatial distributions for peak parameters of spherical and cylindrical charges are analyzed.The results show that the near-field explosion loads are affected by the detonation products,and the reflected overpressure histories exhibit multi-peak and jagged form,which are due to the effects of multiple reflection waves and the complex flow of detonation products after the Mach region.The inverse of pressure and density gradient between detonation products and shock wave interface leads to the Rayleigh-Taylor instability effect.The generated interfacial microjets of detonation products promote the complexity of multiple reflection wave structure,resulting in large uncertainty of measured results of near-field reflected loads.The near-field incident overpressure curve shows a typical double-peak structure,which comes from the air shock wave and detonation products.Due to the structural effects of charge,the incident wave loads of cylindrical charge distribute non-uniformly along the axial and radial directions.The spatial distribution of incident parameters drastically varies when the azimuth angle is between 30°-60° because of the bridging wave effects.The modified predictive model can capture the incident peak overpressure and impulse in the range of 0.06m/kg^1/3<Z<1m/kg^1/3 for cylindrical charge(L/D=0.8)with center initiation under arbitrary azimuth angle,and the relative deviations among predicted results and numerical results of incident peak overpressure and impulse are less than 20%.

In order to ensure the safety, reliability, high-quality, and efficient operation of tank and armored vehicle power systems in complex environments, the development of on-board power systems characterized by active flexibility, collaborative optimization, and flexible interaction is an important direction for the future generation of fully electric combat vehicles. The source-grid-load-storage collaborative optimization and safety control of tank and armored vehicle power systems with electrification as a characteristic are studied. The necessity and challenges of developing the power systems are elaborated from the aspects of inherent conditions and external driving forces. Then, the core content and key technologies of source-grid-load-storage collaborative optimization and safety control for power systems are introduced from the perspective of architectural design. This includes the active flexible safety control technology used in extreme environments, the multi-timescale optimization and scheduling technology used in normal environments, as well as the flexible dynamic control technology used in scenarios with significant disturbances. Furthermore, in conjunction with the concept of a “resilience” power system, the performance characteristics of power systems based on “resilience” optimization and control when facing extreme or unexpected events are discussed, which can provide a reference for the future development of tank and armored vehicle power systems in China.

In view of the application defects caused by physical and chemical surface properties of nano-aluminum powder in the field of energetic materials, the controllable preparation methods, protection reactivity methods, and the changes in thermal and energy performance of nano-aluminum powder before and after protection were reviewed. The advantages and disadvantages of typical preparation methods and coating methods were compared, and the influence of coating layer on the thermal reactivity of modified system was analyzed. On this basis, the future development direction of nano-aluminum powder was put forward: developing methods to improve the dispersion of nano-aluminum powder in composite energetic materials; exploring the influence of the interfacial surface bonding method between the coating material and nano aluminum powder on the properties of the system; further application researching of modified nano aluminum powder. Future research should further concentrate on exploring the environmental compatibility of modified nano-aluminum powder to enhance its performance under complex conditions. 66 References are attached.

In order to improve the damping performances of suspension systems for tank and armored vehicle, a basic structure with"inerter-spring” quasi-zero stiffness is proposed. Dynamic simulation and parameter optimization of inerter continuous control and inerter on-off control are carried out with the parallel structure of inerter, spring and damper as suspension system. The results show that the vibration acceleration of vechile body is greatly reduced and the ride comfort is obviously improved with the quasi-zero stiffness control strategy. At the same time, the damping coefficient is reduced and the damping efficiency is improved. By analyzing the instantaneous power of each component in the process of suspension damping, it is found that the controllable inerter plays an role in energy compensation so that a part of the vibration energy can be transferred and converted dynamically and repeatedly between the spring and inerter, breaking through the traditional damping mechanism of spring buffer energy storage and damping heat generation energy consumption, and achieving better damping efficiency.

Aiming at the mechanism, regularity characterization, influence factors and inhibition of ingredient migration in propellants, gun propellants and explosives, the ingredient migration theories which are mainly driven by concentration gradient and polarity action were introduced. The characterization methods of migration ingredients amount and migration ability based on advanced analytical techniques and migration kinetics were summarized. The effects of temperature, intermolecular interactions, crosslinking density, steric hindrance, structure, and other factors on ingredient migration were elaborated. The migration inhibition methods including chemical synthesis, material modification, and additive methods were discussed. The development directions of establishing rapid and non-destructive characterization methods of ingredient migration, improving migration models and synthesizing new ingredients with high anti-migration performance were proposed.Attached with 79 references.

From the perspectives of reducing the influence of external stimuli and optimizing the structural design of energetic materials, the desensitization mechanisms of single compound energetic materials under different desensitization strategies are reviewed, including buffering, lubrication, conduction, heat absorption and insulation, improving the quality of energetic crystals and enhancing the stability of energetic molecules. The comprehensive desensitization mechanisms of multi-dimensional desensitization strategies such as using multifunctional desensitization materials and coupling various desensitization means are analyzed. The development directions of desensitization of energetic materials in the future are put forward: to develop energetic materials with both high-energy and insensitive characteristics, to research the relationship between desensitization mechanism of energetic materials and operational environment, and to build up universal quantitative description models of sensitivity from the molecular scale, providing theoretical guidance and technical support for designing new high-energy insensitive energetic materials. 93 References were attached.

When using infrared imaging to detect the scenes of flames generated by high-temperature combustion of objects and high-temperature fragments generated by object explosions,the rapid increase in scene temperature within the infrared imaging field of view leads to an increase in the dynamic range of infrared imaging,the image saturation,the loss of detail information,and the submergence of weak targets by high-temperature backgrounds.Therefore,it is urgent to develop an anti-fire interference high dynamic infrared imaging detection technology.This article briefly introduces the current development status of high dynamic infrared imaging technology with anti-fire interference capability.On this basis,the development trend of high dynamic infrared imaging detection technology with anti-fire interference capability is analyzed.

With the development of weapons and equipment towards diversification, versatility and systemization, modern warfare requires the increasingly high levels of command and decision-making in terms of overall planning, timeliness, and scientificity. The construction of task planning systems for major military powers is urgently needed and developed rapidly. In order to better promote the research of task planning systems, a comprehensive review is conducted on the tactical-level task planning methods. This paper reviews the development history of task planning systems and the methodological framework of tactical-level task planning, with a focus on summarizing the main implementation methods and future development directions of tactical-level task planning. In terms of the main implementation methods, the main methods involved in various aspects such as task description, task decomposition, task allocation and scheme evaluation are overviewed and analyzed. In terms of future development direction, the suggestions on standardization, universality, credibility, and other aspects are put forward.

For solving the problems of nitrogen escape and splash in the droplet transfer process of high-nitrogen steel additive manufacturing, the experiment of droplet transfer in an ultrasonic frequency pulsed gas metal arc (UFP-GMA) additive manufacturing is carried out, and the influences of different ultrasonic frequency pulsed current superposition modes and pulse current frequencies on the stability of high-nitrogen steel droplet transfer are studied, The process parameters that can realize the stable droplet transfer of high-nitrogen steel additives were obtained. The experimental results show that the of one-pulse-one-droplet transfer can be realized under the pulsed gas metal arc (P-GMA) process conditions, but the transition stability is poor and the splash is obvious. Superimposing the ultrasonic frequency pulse current at the base current stage of P-GMA or both at the base and peak current stages is not conducive to the droplet transfer, and the problems such as short circuit and droplet explosion are prone to occur. When the low-frequency (20 kHz) pulse current is applied during the peak stage, its effect on droplet transfer is minimal. However, the medium-frequency (40-60 kHz) pulse currents can be superimposed to inhibit the generation of large particle splash, leading to improved stability in droplet transfer, but many small splashes will be formed during the transition when the frequency exceeds 60 kHz.

Thermobaric explosive is an fuel-rich explosive that can inflict severe damage to facilities and personnel in confined spaces due to the long-term pressure generated by explosion and combustion, as well as high-temperature fireballs. Thermobaric explosive involves the propagation of detonation waves in the charge, the scattering of fuel particles in space, and the subsequent combustion process of fuel particles. The coupling process of multi-scale, multi-material, multi-factor and multi-physical field causes the thermostatic damages, which is a significant area of damage research. This paper primarily discusses the research advances in the theoretical underpinnings of formulation design, the impact of formulation's primary components on thermobaric explosive performance and the performance evaluation of thermobaric explosive. It highlights that the future developments in thermobaric explosives will focus on the high chemical potential metal fuels and energy release techniques.Models for simulating the performance of thermobaric explosives should also be highly regarded. In conclusion, the formulation design based on large-scale data from simulations and tests will be a mainstay for driving the development of thermobaric explosives.

The magnetic gradient tensor system (MGTS) is the application basis for detecting the full tensor gradient field of magnetic target. Regional magnetic anomalies leads to a magnetic gradient tensor field, which MGTS uses as an information source to achieve the magnetic gradient tensor measurement through the differential calculation between vector magnetic sensors. Compared to the magnetic total field and vector field detection equipment, MGTS has high resolution, large information content, and strong anti-interference ability, which can obtain more potential physical property information of targets. The progress of target detection technology based on MGTSs worldwide is studied to provide theoretical reference and technical support for the modernization and informatization construction of magnetic detection equipment in China. The development process and stages of modern magnetic detection technology are elaborated, and then the two types of MGTSs based on superconducting technology and flux gate method, as well as their applications areintroduced and summarized. The calibration, compensation, noise reduction, magnetic target positioning and recognition technologies of MGTSs are reviewed. Finally, the design ideas for future high-precision magnetic gradient tensor detection instruments are prospected, and the current problems and development trends of various key technologies for magnetic gradient tensor detection are summarized.

Maritime manned/unmanned collaborative systems play a crucial role in enhancing naval operational effectiveness and represent a significant direction in the development of modern naval equipment. This paper focuses on the development of maritime manned/unmanned collaborative systems, reviews the current developing status and relevant foreign projects, clarifies the main characteristics of the systems, condenses and analyzes the scientific issues and key technologies involved, and ultimately provides a comprehensive survey on the development of maritime manned/unmanned collaborative systems. In the future, intelligence, modularity and sparsity will become the important directions for the development of maritime manned/unmanned collaborative systems. However, due to the contradictions between system autonomy and controllability, the development of intelligence and maritime constraints, and the features of manned/unmanned collaboration and existing collaborative frameworks, the system will also face challenges in scale, diversity, security, and intelligence-related aspects.

In order to enhance the maximum dispersal speed of fuel during the explosion of fuel-air explosive (FAE) devices and achieve a more uniform speed distribution, the paper investigates the influences of detonation methods on the radial maximum speed of fuel dispersal in FAE device. Numerical simulation techniques are employed to analyze the influences above while maintaining the overall structure of the existing device. Specifically, the ALE algorithm implemented in LS-DYNA software is utilized to numerically simulate the fuel dispersal in a frustum-shaped FAE device. The changes in radial dispersal speeds of nodes located at identical positions under the conditions of single point initiation, multi-point initiation and approximate line initiation, are compared. The results demonstrate that positioning the initiation point closer to the unit exerts a restraining effect on the dispersal motion of the fuel within that specific element. Additionally, for a certain point on the fuel, the adoption of the approximate line initiation method proves effective in achieving a more uniform dispersal of fuel cloud and mist. This finding serves as a foundational step towards the further refinement of numerical simulations concerning FAE explosive fuel dispersal.

点火过程是内弹道的初始阶段,但由于点火过程的复杂性以及点火机理仍然不完善,点火过程始终不能与内弹道有机结合,使得目前工程上的内弹道计算只能忽略点火过程而直接选择点火压强作为计算初始点。以零维内弹道理论为基础,建立了点火过程3个阶段,即点火诱导期、火焰传播期和充气期的简化理论模型,可以与零维内弹道有机结合,从而完成了内弹道从环境压强(而不是点火压强)开始计算的完整过程。通过实例计算与验证,该模型能够很好展示在点火阶段燃烧室压强的建立过程,并可以计算得到点火延迟时间、火焰传播时间、点火药流量等点火参数,具有较高的预示精度,满足工程计算要求。研究表明,建立的点火过程理论模型与传统零维内弹道一样计算简便快捷,并具有较好精度的工程应用化特点。研究结果对于完善固体火箭发动机内弹道理论、提高固体火箭发动机内弹道预示精度,均具有重要的实际应用意义。由于采用了简化的点火过程理论模型,该结果不能直接用于点火性能的研究,只能用于零维内弹道性能的预估与计算。

Aiming at the pyrolysis and combustion process of the near burning surface of the pasty propellant, the laser ignition combustion experiment of the pasty propellant were carried out. At the same time, the pyrolysis and combustion characteristics of the near burning surface region of the pasty propellant were studied based on the multiphase chemical reaction numerical solver developed by the research group and the 14-component and 14-primitive chemical reaction equation. The macroscopic structure of propellant combustion flame was obtained through experiments and the burning rate of the pasty propellant was measured under constant pressure conditions. The combustion flame structure and chemical reaction sequence of the pasty propellant under constant pressure conditions were analyzed by numerical calculations. The effects of different ambient pressure on the combustion process of the pasty propellant were calculated. The results show that the fitted burning rate curve was in good agreement with the experimental results. In the range of experimental pressure, the burning rate of propellant in the combustion chamber of pasty rocket engine could be predicted well. The decomposition of AP is the first reaction in the combustion of pasty propellant, and the higher ambient pressure limited the diffusion of primary combustion gases, but enhanced the thermal feedback effect on the pasty domain, which increased the burning rate of the pasty propellant.

With the wide application of intelligent collaborative algorithm and autonomous technology in the field of air,space and sea equipment,the multi-domain cluster distributed collaborative autonomous control technology has also been deeply studied,and significantly improved the degree of intelligent autonomy of unmanned equipment.Based on the development needs of distributed intelligent autonomous control technology of multi-domain cluster,this paper reviews the relevant references related to multi-domain cluster distributed intelligent autonomous control technology and the research status at home and abroad.The relevant strategies,key research directions and advanced methods of multi-domain cluster collaborative autonomous control technology are deeply analyzed.The relevant key technologies and methods are summarized,and the future development trend is discussed.This paper provides a reference for improving the collaborative autonomous control ability of unmanned cluster system.

The overload signal of penetrating projectile is of vital importance to reflect the physical process of penetration, which further helps to reveal the mechanism of penetration resistance and the structural response of projectile. It is also an important basis for designing the projectile-fuze system and achieving the precise target strikes.The overload signal is divided into four components: rigid body deceleration, structural response of projectile, response of connection structure and interference signals of sensors. The sources and characteristics of the four components are introduced, and the modeling and evaluation methods for the vibration and sensor-related signals of projectile-fuze system are discussed. For analyzing the components of overload signals, the low pass filtering, mechanical filtering, modal decomposition, wavelet transform, and blind source separation methods are discussed respectively. The accuracies, adaptabilities, real-time performances, and applicabilities of the methods above are also compared. The real-time requirements for overload signal processing, the signal reconstruction methods, the form of rigid body deceleration in complex penetration environments and the challenges brought by high-speed penetration scenario are discussed. Based on the current research status of overload signals processing of penetrating projectiles, the existing problems and possible future research directions are summarized.

To support the theoretical design of the hypersonic missile's terminal effect and meet the development demand of penetration mechanics theory of non-circular projectiles, the penetration mechanism of non-circular projectilesis a key scientific problem required to be solved. A comprehensive review is conducted on the penetration behavior, penetration mechanism, ballistic stability, and structural response of non-circular projectiles.It is a review and summary of the existing research work, aiming to establish a basic framework for researching the penetration problem of non-circular projectiles.Moreover, the new phenomena and mechanisms introduced by the structural changes of non-circular projectiles are highlighted. Three suggestions for the future research of the non-circular projectiles are put forward for the reference of relevant researchers.

Personnel are a critical factor in warfare.The damage effects of three types of damage elements,namely,shock wave,thermal effect and fragments,against personnel,are assessed based on the anti-personnel criterion through numerical simulation,experiment and theoretical computation tools.A damage zone of shockwave overpressure against personnel is delineated,and the relationship between scaled blast distance and personnel damage level is established,resulting in the minimum scaled blast distance of damage to personnel being 8.155m/kg^1/3.The spatial distribution of explosion thermal effect is calculated,and the free-field non-fuel air explosive or thermobaric bombs are not suitable for separate assessment of thermal effect on the personnel killing effect is put forward.The generation process of fragments is numerically simulated to obtain the quality,quantity and velocity of fragments.The simulated results are compared with the theoretically calculated results to assess the damage effect of the specific kinetic energy of fragments to personnel.The conclusions can provide reference for the design of warhead and the protection of battlefield personnel.

Explosive smoke bombs are of great significance in countering the infrared-guided weapons and protecting the high-value military targets. At present, most of the smoke simulation models do not take into account the vector information of explosion and the near-ground particle diffusion effect, and the authenticity of the explosion smoke simulation is low in the near-ground scene where the wall effect and the air turbulence phenomenon are significant. For the poor simulation accuracy of explosive smoke bomb in near-earth scene, a simulation method of explosive smoke bomb structure model in near-ground scene is proposed. This method uses the particle position information to replace the life cycle of the particle model. Based on the Gaussian puff model, a near-ground smoke explosion model considering the explosion flying direction of bomb and the wall effect is constructed to improve the simulation accuracy of near-ground smoke bomb explosion scene. The structural similarity (SSIM) analysis is used on the simulated image. After the best parameter selection experiment, the SSIM value reaches 0.944 3 and the standard deviation is ±0.000 5. The SSIM value of the proposed model is 0.011 2, 0.132 9 and 0.006 3higher than those of the particle system-Gaussian smoke model, ellipsoid explosion model and explosive smoke bomb model，respectively.The experimental results shows that the proposed model has clear direction information in smoke simulation, stronger ability to express the details of smoke turbulence and wall effect, and higher accuracy in the simulation of near-ground smoke bomb explosion scene.

In order to obtain the optimal casting process parameters of HTPB composite solid propellant, the constitutive model for the flow process of propellant slurry was established based on the rheological properties of HTPB propellant slurry adopting a combination of experimental and theoretical simulation methods. The casting process of HTPB composite propellant slurry was simulated by using the finite element software, and the reliability of the simulation results was verified through experiments. Moreover, the casting process of the propellant slurry was optimized and the optimal casting process parameters were obtained. The results show that HTPB propellant is a typical pseudoplastic fluid, and its viscosity decreases with increasing shear rate. The porosity and the casting time are 12.5% and 11.25%, respectively after comparison of experiment and simulation. Among them, temperature has the most significant impact on casting time, and vacuum degree has the most significant impact on porosity.

Time series matching technology is widely used in vehicle handling consistency evaluation.An evaluation method of vehicle throttle control action consistency based on segmented dynamic time warping (DTW) is proposed for the motion consistency evaluation of a coach vehicle in the process of cooperative driving.On the basis of the inconsistent number of sample data points in the cooperative control test of coach vehicle and the slope constraint of dynamic bending path, the traditional DTW rectangular search area is transformed into a parallelogram search area to reduce the area of the search area by changing the slope of search path, thus greatly reduce the calculation amount.Four groups of typical throttle action curves are selected to carry out 50 rounds of iterative experiments for verification, and the DTW distance matrix between the action curves of real vehicles A and B is calculated by segmented DTW method.A minimum deviation leveling method is used to combine the cluster objects for the actions of vehicles A and B, so as to complete the consistency evaluation of throttle action data.The experimental results show that the average matching accuracy of the improved DTW algorithm in each throttle action can reach 89.2%, which is about 3.2% higher than that of the single DTW algorithm, and the average matching time is about 92.45s, which is about 12.6% lower, thus verifying the feasibility and superiority of the segmented DTW algorithm in the consistency evaluation of throttle action.

The working principles and recent technological advancements of high-speed photography, spectroscopic testing, laser interferometry, and terahertz Doppler wave measurement techniques were introduced. Also, the application of these techniques in the field of explosive detonation testing was discussed. Among them, high-speed photography and laser interferometry are widely used in the measurement of detonation velocity, pressure, and shock initiation. Spectroscopic testing is mainly applied to detonation temperature measurement and detonation product composition analysis, while terahertz Doppler wave measurement is employed for explosive detonation wave measurement. The advantages and disadvantages of optical-electronic testing techniques in detonation performance research and provided an outlook on the future development of detonation performance testing technologies were analyzed. It is concluded that strengthening the study of micro-scale testing technologies for explosives, expanding the application of current optical-electronic testing techniques, and integrating data processing with big data technologies are key areas for future research in explosive detonation performance. 128 References were attached.

To address the precise attitude control of a serial wheel-legged robot,a motion control framework with offset-free model predictive control as the core is proposed.Firstly,a concentrated center-of-mass dynamics model is established,which considers the mass distribution of body,legs,and wheels.Based on the concept of active disturbance rejection control,the unmodeled characteristics of the model are treated as disturbances,and an extended state observer is established to estimate and compensate for the unmodeled characteristics.Furthermore,the joint control is introduced to solve the problem that the wheels are easy to roll and cause leg abduction during attitude adjustment,and an additional wheel control strategy is designed to assist in constraining the leg state.The hardware experiments are conducted on the serial wheel-legged robot.The results show that the proposed motion control framework can accurately track the desired attitude signal,effectively suppress the terrain disturbances and external force disturbances,and ensure the driving stability and disturbance resistance capability of the robot.

In order to improve the safety performance of HMX, HMX/FOX-7 nano-cocrystals with different molar ratios were prepared by the ultra-low-temperature-assisted recrystallization method, where FOX-7 with low sensitivity was used as another component of the binary cocrystal. The morphology, structure, and thermal properties of the prepared HMX/FOX-7 cocrystals were characterized by SEM, XRD, FT-IR and DSC-TG, and their mechanical sensitivities were analyzed. The results show that the prepared HMX/FOX-7 crystals are mainly porous structure stacked with spherical particles, and their particle sizes are distributed primarily in the range of 0.1—0.5μm. During the formation of HMX/FOX-7 nano-cocrystals, the “low-temperature freezing” of the HMX/FOX-7 solution from liquid nitrogen and the formation of hydrogen bonding among HMX and FOX-7 have an significant influence on the formation of HMX/FOX-7 nano-cocrystals. The apparent thermal decomposition enthalpies of HMX/FOX-7 nanocrystals is significantly higher than that of the raw HMX and FOX-7, and increases with the increase of HMX content. The mechanical sensitivity of each HMX/FOX-7 nano-cocrystal is substantially reduced compared with that of the raw HMX. When the molar ratio of HMX and FOX-7 is 1:3, the prepared HMX/FOX-7 cocrystal has the lowest mechanical sensitivity, where the impact sensitivity is higher than 45J and the friction sensitivity is 288N.

Unexploded ordnance refers to ammunition that has been disarmed, detonated, ignited or otherwise prepared for use or has been used, and has not exploded due to fuze failure, functional failure, design defects or other reasons after igniting, throwing, launching or burying for various reasons. The research status of safety disposal technology of unexploded ordnance at home and abroad is described,the unexploded ordnance detection technologies, such as magnetic detection, sound-magnetic compound detection and optical detection, and the non-contact disposal and destruction technology principles, such as burning treatment, blasting destruction, cutting treatment, are analyzed, and the advantages and disadvantages of different detection and disposal technologies and their application scenarios are summarized. At last, it is pointed out that the detection and disposal technologies of underwater unexploded ordnance are the focus of the current national defense field, and also the research hotspot. The research on key technologies of safe disposal of unexploded ordnance can provide theoretical basis for unmanned, safe and environmentally friendly detection and disposal of unexploded ordnance in the future.

Ballistics is one of the foundational disciplines in weapons science and technology,closely related to the development of weapons technology. With the rise and development of intelligent projectiles and rockets,the theory and technology of intelligent ballistics will be a major direction for the future development of exterior ballistics. Nevertheless,how to understand the concept,connotation,and functions of intelligent ballistics,as well as its differences from existing projectiles and rockets in terms of flight trajectories,the key technologies it relies on,the challenges involved,and the issues that should be considered for the subsequent development,are still under discussion. Based on the theory and technology of exterior ballistics and focusing on the future development of exterior ballistics,this article tends to analyze and organize the aforementioned issues with the aim of providing assistance for the future development of intelligent ballistics theory and technology. It should be noted that the development of intelligent ballistics theory and technology has introduced numerous new problems,concepts,terminologies and technologies for exterior ballistics,which require continuous exploration,refinement,and gradual perfection by researchers in the field of exterior ballistics through ongoing research. This article merely serves as a starting point,hoping to inspire more researchers in the field of exterior ballistics to engage in this area of study and gradually develop a theoretical framework.

Powdered fuel has broad application prospect prospects as fuels or additives in detonation propulsion systems due to their high energy density and excellent stability. Based on the classification of fuel types for gas-solid two-phase detonation and the application of powder detonation propulsion technology, the theoretical research progress on the detonation initiation and propagation characteristics of powdered fuel in oxidizer gas and gas fuel/oxidizer gas at domentically and internationally is reviewed. The theoretical and engineering aspects of heterogeneous detonation and hybrid detonation are summarized, highlighting the key factors affecting the initiation and propagation characteristics of gas-solid two-phase detonations, as well as important conclusions. Furthermore, the two-phase detonation engines are reviewed from the perspectives of application prospects, propulsion performance, difficulties and challenges, etc. Based on the summary of the numerical and experimental research status of powder detonation engines, the future research work that needs to be carried out is prospected.

The dynamic and accurate tracking of the center-of-mass reference trajectory in complex terrain is crucial to ensure the stable execution of tasks for wheeled-legged hybrid platform. A dynamic locomotion control strategy is proposed to enhance the terrain adaptability and pose tracking capability of the platform. Taking into account terrain factors, a single rigid body dynamics model including wheel dynamics is established. The system dynamics model is then transformed into the standard form of state-space equations through an approximate simplification. Considering the coupled motion of the wheels and legs, a hybrid locomotion control method based on feedforward and feedback torques is introduced. The quadratic programming algorithm is used to solve the optimal ground reaction forces, and the Jacobian matrix is used to map these forces into the joints for feedforward torque generation. To address the external disturbances caused by the environment that may hinder the system's ability to perform optimization calculations in a short time frame, the joint torque feedback control is introduced to promptly correct the pose tracking errors. This enables the system to respond rapidly and accurately to the external disturbances, thus effectively improving its robustness and stability. Simulated results demonstrate that the proposed method significantly enhances the dynamic pose tracking accuracy of the platform in complex terrains, ensuring smooth platform operation. This method provides strong support for the engineering application of wheeled-legged hybrid platforms in complex terrains.

According to the demand of axial cold launch,an axial cold ejection device using high-pressure nitrogen as ejection energy was designed to avoid the pollution of the internal space of the platform. The structure composition,working principle and main design points of the axial cold ejection system were introduced. By using the ideal gas equation of state,mass and energy conservation equation and aerodynamics,the mathematical models were established for the high-pressure chamber,low-pressure chamber,valve port gas flow,and missile motion of the axial cold ejection system. In order to improve the separation speed and reduce the overload peak,based on the established mathematical models and the internal ballistics structural-parameters,VB language was used to program. Through simulation calculation and analysis,the main structural parameters of the ejection system such as cylinder initial pressure,volume,initial volume of low-pressure chamber,electromagnetic valve orifice,natural frequency,damping ratio and piston diameter,were studied to determine the impact on missile separation speed and launch overload. The influence of various structural-parameters change on the missile separation parameters was found,and the mechanism of the influence laws was analyzed. This study provides a theoretical basis for the optimization of the structural parameters of ejection system,and provides a theoretical reference and basis for the internal ballistics design of the same type of axial cold ejection launcher.

Linear focusing fragment warhead makes the fragments disperse at an equal velocity and focus linearly by taking advantage of the design of charge generatrix and fragment arrangement, which can exert structural cutting damage to a target. In order to study the influence of structural parameters of linear focusing fragment warhead on the dispersion characteristics of fragments, the fluid-structure interaction (FSI) algorithm is used to numerically simulated the focusing process of fragments. The numerically simulated results reveal the linear focusing mechanism of linear focusing fragment warhead. The typical linear focusing process includes fragment driving stage, fragment focusing stage, focusing completion stage and fragment dispersion stage. The effects of warhead size, fragment arrangement, fragment mass and intersection velocity on the dispersion and spatial distribution characteristics of fragments are further obtained by numerical simulation. The results show that, with the increase in charge length from 0.3 m to 0.5 m, the standard deviation of fragment velocity increases from 125 m/s to 147 m/s, the focusing completion time is 490 μs, 585 μs and 590 μs, respectively, and the width of perforation dense distribution increases from 135 mm to 234 mm. When the fragment arrangement increases from 15 columnsto 18 columns, the standard deviation of fragment velocity increases from 117 m/s to 125 m/s, the focusing completion time is 470 μs and 490 μs, respectively, and the width of perforation dense distribution increases from 235 mm and 135 mm respectively. When the fragment mass increases from 4.08 g to 9.21 g, the standard deviation of fragment velocity decreases from 137 m/s to 125 m/s, the focusing completion time is 380 μs and 490 μs, and the width of perforation dense distribution is 156 mm and 135 mm, respectively. When the interaction speed increases from 0 m/s to 1 000 m/s, the focusing completion time is 490 μs, 480 μs and 469 μs, respectively, the width of perforation dense distribution increases from 135 mm to 138 mm, and the density of fragment distribution decreases from 640/m² to 630/m²with a rate of about 2%. The research results can provide guidance and reference for the design of focusing warhead.

Based on the application research background of large aircraft impact,the experimental research is conducted on the impact of flying object on a prestressed reinforced concrete target plate.The scaled samples equivalent to flying object and prestressed reinforced concrete target plates are designed using a geometric scaling ratio of 1:6.Finite element analysis software is used to construct the collision models and calculate the impact damage effects of two scaled samples with different structures on the target plate at different speeds.A physical loading test is conducted using an air cannon,and the critical penetration velocity of two scaled samples on 200mm thick prestressed reinforced concrete is obtained by comparing the test results with simulated results.This provides basic data for intuitive prediction/evaluation of the impact response and failure mode of prestressed reinforced concrete containment in nuclear power plants,and also provides design references and basis for prototype collision test schemes.

The temperature fluctuation and magnetic noise in the alkali-metal vapor cell are key factors that restrict the sensitivity improvement of spin-exchange relaxation-free atomic spin gyroscopes. To deal with these two issues, a laser heating method is proposed to perform non-magnetic heating for the vapor cell, thus fundamentally eliminating the magnetic noise, and the graphene films are deposited on the heating surface, and adjacent upper and lower surfaces of the vapor cell for photothermal conversion, thermal conduction, and stray-light interference avoidance. The combination of linear active disturbance rejection control (LADRC）and thermal management technology is used to improve the temperature control accuracy and stability of alkali-metal vapor cell. A linear active disturbance rejection controller based on temperature control system is designed. A thermal structure is designed and graphene film is selected in consideration of heat conduction, thermal convection and thermal radiation. An experimental platform was built for the temperature control system of alkali-metal vapor cell. The result shows that the temperature control accuracy of temperature control system of alkali-metal vapor cell using LADRC and thermal management technology is ±0.003 ℃, and the temperature control stability is 6 mK. This lays the foundation for improving the sensitivity of atomic spin gyroscopes in the future.

A hierarchical multi-agent collaborative decision-making method based on the actor-critic (AC) frameworkis proposed to address the issues of improper task allocation and weak decision consistency in the collaborative decision-making of multiple agents in complex operational environments. The proposed method divides the decision-making process into different levels and utilizes the AC framework to facilitate information exchange and decision coordination among the agents, thereby enhancing thedecision efficiency and combat effectiveness. At the higher level, the top-level agents formulate thetask decisions by decomposing and assigning overall tasks to the lower-level agents. At the lower level, the lower-level agents make action decisions based on subtasks and provide feedback to the higher level. Experimental results demonstrate that the proposed method performs well in various operational simulation scenarios, showcasing its potential to enhance themilitary operational collaborative decision-making capability.

Perovskite is regarded as one potential material for next-generation photovoltaic devices owing to its outstanding photoelectric characteristics which can be easily adjusted by phase transitions.However,the technology for intercepting and preparing the metastable perovskites is still in its infancy.The impact loading method has a significant advantage of high quenching rate,and enables the capture of metastable phases and facilitating their subsequent recovery and preparation.To achieve the impact phase transition treatment of CsPbBr₃,the cylindrical converging shockwaves are generated by the pulsed discharge of cylindrical wire array in water medium for studying the shock-induced phase transition of CsPbBr₃.The delicate control of shock pressure is applied to act on CsPbBr₃ powder by adjusting the charging voltage.After experiments,the samples are recovered and characterized.The characterized results reveale that the shock waves generated by pulsed discharge can induce phase transition in CsPbBr₃ powder under appropriate shock pressures (above 2 GPa).Additionally,the typical phenomena such as grain refinement,lattice distortion and nano-defects are observed in the recovered samples after shock-wave treatment.This study demonstrates that pulsed discharge of cylindrical wire array in water medium is a feasible converging shock wave loading technique,providing a novel approach to shock-induced phase transition loading.

By comparing the differences in the physical and chemical properties, such as the enthalpy of formation and phase transition temperatures of the fluorinated/oxidized products of metal fuels, the characteristics and potential application advantages of fluorination energy release reactions in energetic systems were summarized. The research progress of composite energetic systems based on fluorinated oxidizers, including typical types and characteristics of fluorinated oxidants, as well as their applications in pyrotechnics, propellants, mixed explosives, and aluminum thermites has been reviewed. The research and development direction of the application of fluorine-containing oxidizers in composite energetic systems was prospected. It is pointed out that the systematic computational chemistry research on composite energetic systems based on different fluorine sources should be conducted to understand the thermodynamic and kinetic mechanisms of fluorination reactions and their structure-activity relationships at the atomic/molecular level. Furthermore, research should also be intensified on the fluorine transfer mechanism in combustion reactions and the interfacial fluorine infiltration mechanism under pre-ignition conditions. Based on this, new typical fluorine-containing oxidizers suitable for different scenarios should be developed from the view point of nano architectonics and reaction pathway design. Attached with 137 references.

To investigate the propagation characteristics of detonation waves influenced by lateral expansion with weakly constrained boundaries in a narrow straight channel,a two-dimensional numerical simulation was conducted using H₂/O₂/Ar mixture as the fuel and a detailed chemical reaction mechanism consisting of 48 steps. The study examined the effects of type of weakly constrained gas,temperature,and height of combustible premixed gas on the propagation speed and wave structure of the detonation wave. It is found that using argon or products of combustion as weakly constrained gases has no significant impact on the lateral expansion extent and wave structure of the detonation wave. When the temperature of the weakly constrained gas is 1 000 K,1 500 K,and 2 000 K,the shock wave propagating within the products of combustion exceeds the detonation wave speed,resulting in the generation of an induced shock wave pointing towards the detonation wave. This induced shock wave leads to an increase in the velocity of the detonation wave. Increasing the temperature of the weakly constrained gas from 300 K to 500 K has no effect on the propagation characteristics of the detonation wave. Higher heights of combustible premixed gas results in less loss of velocity for the detonation wave,and there exists a minimum combustible premixed gas height that prevents the detonation wave from extinguishing. When the temperature of the weakly constrained gas is 300 K,the dimensionless critical propagation size of the detonation wave h/λ>0.13. The findings of this study are of significant importance for understanding the mechanisms of lateral expansion losses in detonation waves.

The gel made of styrene-ethylene-butylene-styrene (SEBS) block copolymer and white oil has similar properties to ballistic gelatin. Compared with ballistic gelatin, it has good temperature stability, excellent transparency, and aging resistance. The mechanical properties are comprehensively measured to investigate the feasibility of using SEBS gel as a substitute for ballistic gelatin in trauma ballistic test. First, the quasi-static and dynamic mechanical properties of SEBS gels with four different mass fractions (15%, 20%, 25%, and 30%) are tested using a universal material testing machine and an improved Hopkinson pressure bar to study the impact of copolymer content on the mechanical properties of the gel. The mechanical properties of SEBS gel are compared with those of 10% and 20% ballistic gelatins to determine the mass fraction that is most similar to the mechanical properties of ballistic gelatin. Then, SEBS gels with three different mass fractions (15%, 20%, and 25%) are penetratedusing 5.8mm rifle bullets, and the moving postureof bullet and the temporal cavity evolution of a target are recorded by high-speed photography. The experimental results of SEBS gel are compared with those of the ballistic gelatin with 10% mass fraction. The test results show that the stress-strain curve of 10% ballistic gelatin is between those of 15% and 20% SEBS gels, and the stress-strain curve of 20% ballistic gelatin is between those of 20% and 25% SEBS gels under quasi-static compression. The mechanical properties of 20% and 30% SEBS gels are similar to those of 10% and 20% ballistic gelatins, respectively, at high strain rates. The maximum cavity diameter of 15% SEBS gel is closest to that of the 10% ballistic gelatin, but the cavity expansion and contraction rates of SEBS gel are higher than those of ballistic gelatin. This study provides data support for the replacement of ballistic gelatin with SEBS gel as a new soft tissue substitute.

Kinetic energy missile is a new type of anti-armor weapon that combines the effects of kinetic energy strike and armor penetration, but there is currently no relevant theoretical model available for reference regarding the load characteristics and influencing factors of impact process. The load characteristics of the impact process of kinetic energy missiles are studied. By considering the missile-target action behaviors in different velocity ranges, a calculation model for the impact load of kinetic energy missile body is established. The calculated results indicate that the impact load of missile is directly related to the geometric characteristics, impact velocity, density, strength, and other properties of missile. The change in the impulse of missile is relatively small at low velocity, but at high velocity, the rebound of the shattered mass significantly increases the impulse, and the impulse contribution of the shell accounts for a larger proportion of the impact impulse. The amplitude of impact load curve increases with the increase of shell strength and density, but the influence of density on the load waveform characteristics is more obvious. At the same velocity, the influence of shell strength on the momentum transfer factor of missile is relatively small, but the influence of shell density has a significant effect on it. At the same velocity, the influence of shell strength on the momentum transfer factor of missile is relatively small, while the shell density has a greater impact on it, The transfer factor curve shows a trend of increasing first and then decreasing with the increase in density.

Ducted-fan unmanned aerial vehicle(UAV)can realize take-off,landing and hovering,which has a simple and reliable structure and high safety coefficient.In view of the restricted take-off and landing environment,redundancy of folding wing mechanism and low aerodynamic efficiency of conventional water-air amphibious UAVs,a new dual ducted fan water-air amphibious trans-media UAV is designed.The fuselage is optimized with reference to underwater unmanned underwater vehicle(UUV)and UAV,and the tilting dual ducted fan power system is used.Based on the improved blade element momentum theory,the theoretical formula for calculating the lift of small ducted fan is derived.The structural vibration pattern of UAV as a whole under the mechanical physical field is analyzed,and the aerodynamic performance of the whole vehicle is verified by flow field finite element simulation.The analyzed results show that the calculated results of the improved small ducted fan lift calculation formula are basically consistent with the wind tunnel test results,with the maximum error between the two results is 4.5%,and the designed small ducted fan can provide 20% of additional lift with high aerodynamic efficiency.Through the modal analysis,it is found that the UAV fuselage structure is more stable,and the vibration pattern is reasonable.The wind tunnel test and the test flight verification of the ducted fan water-air amphibious UAV in different media are completed,which proves the feasibility of the UAV design scheme.