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.

To solve the problem of large initial lead angle or significant change in lead angle when missile terminal guidance starts, a 3D time-to-go（TGO）estimation method for lead angle is designed for various missile guidance laws. The missile velocity and target velocity projections are decomposed to establish the relationship equations of relative motion between missile and target on Oxy and Oxz surfaces of ground coordinate system. Based on this, a three-dimensional missile-target relative motion model is established. A first-order nonlinear differential equation is established by using the relative motion equation and proportional navigation control equation of missile and target. The relationship between missile-target distance and lead angle is analyzed. The first-order nonlinear differential equation is solved by using McLaughlin formula. An appropriate inner frame angle is selected based on the change in line-of-sight angular velocity to compensate for the lead angle, and the median average filtering method is used to reduce the error caused by the fluctuation of lead angle. The simulation experiments are conducted by using the proposed three-dimensional missile-target relative motion model. The simulated results show that, when the small angle assumption cannot be established, especially when the angle control of guidance law results in significant changes in the lead angle, the convergence time and maximum error value of estimated error of the lead angle TGO estimation method are smaller than those of other TGO estimation methods.

Gravity dam is a kind of common large concrete hydraulic construction. In order to explore a calculation method for the reflected pressure of shock wave applicable to the near area of hydraulic structure, a method for calculating the reflected pressure of shock wave of the underwater explosion on the rigid wall with clear physical connotation is derived strictly by using the three conservation basic relations of mass, momentum and energy on the shock wave front and the equation of state of condensed medium. Based on the relationship between shock wave velocity and particle velocity in continuous medium, the determination method of the state parameter k of water is given, and the law of state parameter k decaying exponentially with incident shock wave pressure is revealed. It is found that the change of k value has a significant impact on the calculation result of reflected pressure of shock wave when the incident pressure is above 725 MPa. By comparing with the calculation methods proposed by Cole^\[12\], Henrych^\[14\], and Luo, et al^\[15\], and the numerical simulation, the results show that the proposed calculation method has a wider application scope and higher calculation accuracy, and it also reveals theoretically for the first time that the reflection pressure coefficient of underwater explosion shock wave ranges from 2.00 to 4.49.

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.

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 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.

Traditional coating layer for underwater vehicles mainly depend on material renewal and structure optimization, which is difficult to cope with low-frequency active sonar detection. A lightweight, thin and low-frequency broadband underwater acoustic emission unit with high pressure resistance is designed based on the giant magnetostrictive material. The design and optimization process of the core components are analyzed emphatically, and the finite element simulation results are verified by the PSV-400 laser vibriometer. The optimal boundary constraints of the active emitting element are determined through the modal analysis of a fixed radiation panel. Compared with the performance of the emission unit in the original configuration, it is found that, under the premise of maintaining good directivity of underwater acoustic emission, the highest resonance frequency below 2 000 Hz is reduced by more than 10% based on the finite element analysis. Based on the acoustic structure coupling analysis, the maximum radiation source level of active emission unit in the low frequency range is 147.48 dB, which is increased by 4.65%. The frequency bandwidth of transmitting unit exceeds 1 500 Hz when the sound source level is higher than 100 dB. This means that there is a higher sound power level in this frequency bandwidth range. The emission unit can provide technical support for the application of array in the large-scale acoustic cladding. It has certain academic research value and broad engineering application prospect.

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.

In order to study the effect of probe structure on the microwave ignition performance, four probes were used to test the microwave ignition delay time of Ti/CuO ignition powder and the probe structure was optimized by simulation. The influence of the probe parameters(length, coating thickness, tip taper, and coating thickness)on the electric field intensity was obtained. The results show that the electric field intensity of the probe tip significantly affects the ignition delay time. Under 2.45GHz and 50W microwave, the maximum electric fields of the four probe tip are 1800, 190, 34, and 53kV/m, respectively. The ignition delay time of Ti/CuO are 222.6, 660.5, 949.1, and 921.3ms, respectively. When the probe length is 26mm, under 2.45GHz and 50W microwave,the PTFE dielectric layer length is 8mm and the thickness is 0.75mm, the tip taper is 0.243 and the gold coating thickness is 5μm, the electric field intensity can be increased from the original of about 10kV/m to about 1000kV/m and the electric field distribution is concentrated at the tip.

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.

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.

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.

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.

The propulsive performance of a high Mach-number combined cycle engine aircraft(CCEA)operating in a wide flight-range is affected by the flight conditions/attitude and mode transition,which further affects the flight mission performance. In order to evaluate the mission performance of the combined cycle engine aircraft as real and fast as possible,a fast evaluation method of the combined power aircraft mission-performance considering the mode transition was proposed,and the effects of different flight envelopes and different mode transition intervals on the flight mission performance were quantitatively studied. Firstly,the flight dynamics model of high Mach-number aircraft was established,and the flight attitude was taken into account in the mission analysis. Then the calculation model of non-installed and installed performance of the combined cycle engine was established,which can simulate the performance of the engine in real time in the flight envelop. Finally,a modal transition simulation model was established to analyze the effect of modal transition process on flight performance. The results indicate that the cruising altitude of the studied CCEA with Mach number of 5 increases from 20 km to 27 km,and increases by 18.3%. The total range increases by 21.9%. Furthermore,the modal transition interval shifts from low Mach numbers(Ma=2-2.3)to high Mach numbers(Ma=2.2-2.5). The climbing acceleration distance increases by 8.4%; the climbing acceleration time increases by 5.8%.

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.

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.

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.

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.

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.

The temperature rise of the high-speed permanent magnet synchronous machine (PMSM) for aviation aircraft supplied by PWM voltage might be significant because of its high loss density and poor heat dissipation condition. What's worse, high temperature increases the demagnetization risk of Halbach-array magnets, which impairs the reliability of operation. In allusion to above problems, a multi-objective optimization method of high-speed PMSM based on Nelder-Mead algorithm is proposed. The loss and temperature rise are selected as optimization objectives. Field-circuit coupled finite element analysis method is used to calculate the loss of the machine powered by T-type three-level converter, thus calculating the temperature rise. The optimal design areas are searched by using the optimization algorithm, and the optimal solution is achieved. The flux density distribution and eddy current loss in the Halbach-array magnet are analyzed, and then the design of magnets is optimized to suppress eddy current loss and demagnetization. A 300 kW, 30 000 r/min high-speed PMSM was designed and manufactured. Simulated and experimental results show that the proposed design method could realize multi-objective optimization and suppress demagnetization effectively.

Three-dimensional woven preform (3DWP), because of its better formability and significant interlaminar bearing capacity, is expected to achieve the integrated molding of helmet curved surfaced, and reduce the waste of cut and raw materials. Because of the structure characteristics of ballistic helmet with multiple curved surfaces and high curvature, it is important to study the deformation mechanism of 3DWP during curved surface forming for the integrated forming of helmet. The curved surface formability of a layer-to-layer interlock 3DWP with stuffer yarns under high curvature and large deformation is studied systematically. The deformation mechanism and wrinkle defects formation mechanism of 3DWP are described comprehensively from in-plane/inter-layer dimensions and macro/mesoscale. The results indicate that significant in-plane shear deformation of 3DWP can be observed along the 45°direction at the same latitude. The maximum in-plane shear angle of the concave surface is 38°, which is greater than that of the convex surface. The maximum inter-layer shear angles of 3DWP warp and weft rows are 34.83°and 27.76°, respectively. After forming, 3DWP has reached 62° intra-ply shear locking angle, which induces the buckling of yarns microscopically and forms the ridged wrinkles macroscopically. In the wrinkle area, the maximum in-plane shear angle is only 4.8°, and the maximum inter-layer shear angle is 18°. This conclusion has guiding significance for structure selection and forming process of reinforced fabric for ballistic helmet in practical application.

During the electromagnetic launching process,the high speed sliding electrical contact about armature-rail is closely related to the accuracy of the rail spacing. Accurate measurement about the rail spacing can effectively guide the design of armature and researching for the matching about armature-rail. According to the cross-sectional,irregularly shaped characteristics,and the changing shape of the railgun. An high-precision measurement method for spacing size was proposed based on the angular bisector characteristic. In this method,the spatial position of two rails was divided into two segments that interest at a certain degree. The angular bisector was adopted as the measurement reference,and a measurement points were taken. The perpendicular lines of the two rails were drawn through the measurement point. The line connecting the two perpendicular feet was defined as the orbital spacing value. Through prototype design,comprehensive system error analysis,and comparative verification,a certain caliber railgun spacing engineering measurement was carried out. The results show that the measurement error is ≤0.05 mm,which satisfies the accuracy requirements. By obtaining accurate data of the rail spacing,an indispensable measurement method can be provided for numerical modeling,assembly process,and performance testing about electromagnetic launch devices.Thereby promoting the engineering application of railgun weapons.

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.

The tracked vehicle dynamics model serves as a foundation for the design of vehicle structure optimization and the development, testing and calibration of control algorithms. However, the user is unaware of the dynamic equations and gradient information of the model created using commercial software, which significantly lowers the efficiency of the optimization of structural parameters and control parameters. Additionally, the poor real-time performance and low solving efficiency of the currently available commercial software have an impact on the development and porting of control algorithm. An improved dynamic model of tracked vehicles, which can satisfy the needs of vertical and horizontal coupling motion simulation, is constructed and simulated based on the derivation of multibody dynamics in order to address the aforementioned issues. A dynamic model of vehicle body considering the three-dimensional coupling motion of space and a dynamic model of track chain including track link are established. By calculating the interaction force between the track links and other components, the vehicle body model, the track chain model and the ground are related, and finally a track vehicle dynamic model with 190 degrees of freedom is constructed. It was compared to the ADAMS Tracked Vehicle Toolkit (ATV) in terms of acceleration, braking, and steering. The simulated results of the proposed simulation model are remarkably compatible with those of commercial software, confirming the accuracy of the approach.

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.

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.

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.

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.

To enhance the energy characteristics and combustion performance of energetic microchips for their application in micro-propulsors, micro-actuators, and micro-detonators, the ECP@Al@CL-20 energetic array were synthesized through in situ growth of energetic coordination polymer(ECP)on copper foil, e-beam deposition of n-Al, and recrystallization of CL-20. The morphology, phase composition, thermal decomposition, combustion performance, and storage life were characterized by SEM, XRD, TG-DSC and high-speed photography. In addition, the functional ECP@Al@CL-20 energetic microchips were integrated with microelectro mechanical system(MEMS)and subjected to capacitor ignition tests. The results show that the ECP@Al@CL-20 energetic array reduces heat transfer efficiency from outside to inside due to the low thermal conductivity of ECP, resulting an increase of 8.5℃ in the exothermic peak temperature compared to pure CL-20, thereby increasing the thermal stability of ECP@Al@CL-20. The ECP@Al@CL-20 energetic array has excellent combustion performance, its self-sustaining combustion time(340ms)is much higher than that of ECP@Al(120ms), and it can be ignited under 15mJ of input energy.

Imidazolium 2,4,5-trinitroimidazole was synthesized by nitration of 2,4,5-trinitroimidazole(2,4,5-TII)in different mass fractions(20%, 50%, 65% and 98%)of nitric acid using micro-channel reaction technology, respectively. The structure was characterized by fourier transform infrared spectroscopy(FT-IR), nuclear magnetic resonance spectroscopy(NMR), elemental analysis(EA)and melting point testing. Results show that by using micro-channel nitration reaction technology, the optimal process conditions for preparing imidazolium 2,4,5-trinitroimidazole from 2,4,5-TII are as follows: the molar ratio of 2,4,5-TII and fuming nitric acid is 1:20, the reaction time is 6 min, the reaction temperature is 70～72℃, and the yield is 21.8%. Compared with the conventional tank reactor process, the micro-channel reaction process has the advantages of shorter reaction time, lower dosage of nitration reagent, slightly lower reaction temperature and slightly higher yield. However, it can not completely avoid the occurrence of side-reaction of oxidation.

From the development trend of modern artillery and ammunition technology,the problems faced by the internal ballistics of artillery were analyzed. The development direction of internal ballistics theory and technology is mainly reflected in three aspects. The first aspect is to improve the combat effectiveness of conventional solid propellant artillery. The second aspect is to develop internal ballistics theory and control technology that is matched with the launch methods of special ammunition such as guided munitions. The third aspect is to study the internal ballistic theory and control technology of new energy artillery. On this basis,combined with the research status at home and abroad,several key issues were reviewed,proposing research strategies.

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.

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.

To study the explosiveness of biomass fuels, TG-DTG thermogravimetric analysis was used to analyze the combustion performance and kinetic parameters of several common biomass fuels(straw, sawdust, peanut shells)and their mixtures. The microstructures of these fuels were analyzed using scanning electron microscopy(SEM). Additionally, an elemental analysis of the wood powder and peanut shell powder mixture was carried out using an elemental analyzer. Based on the elemental composition, the amount of oxygen required for its oxidation reaction was calculated, and an explosion test was subsequently conducted. The results showed that the mixed fuel(wood powder and peanut shell powder in a 1:1 mass ratio)exhibited high stable combustion characteristics, flammability index, and overall combustion performance. The activation energy was moderate, and the surface appeared porous and rough, with more free surfaces and a larger specific surface area, which facilitated combustion. In an experiment,40g of this mixed fuel was loaded into a steel pipe with a diameter of 40mm, a length of 200mm, and a wall thickness of 1.5mm, and filled with 5MPa oxygen. The mixture was successfully detonated by a No.8 electronic detonator without producing toxic gases. The steel pipe was blasted into fragments of different sizes, with most fragments measuring less than 50mm. The research results indicate that biomass fuel can exhibit explosiveness under certain conditions.

Polarization can improve the autonomous reconnaissance capability of unmanned aerial vehicle, but it is easily interfered by the variation of detection angle and target materials, which affects the robustness of polarization detection. In this paper, a real-time low-altitude camouflaged target detection algorithm of YOLO-Polarization based on polarized images is proposed. The coded image fused with multi-polarization direction information is used as input, the 3D convolution module is applied to extract the connection features from the different polarization direction images, and a feature enhancement module (FEM) is introduced to further enhance the multi-level features. In addition, the cross-level feature aggregation network is adopted to make full use of the feature information of different scales to complete the effective aggregation of features, and finally combined with multi-channel feature information output detection results. A dataset consisting of polarized images of low-altitude camouflaged targets (PICO) which include 10 types of targets is constructed. The experimental results based on PICO dataset show that the proposed method can effectively detect the camouflaged targets, with mAP_0.5:0.95 up to 52.0% and mAP_0.5 up to 91.5%. The detection rate achieves 55.0 frames/s, which meets the requirement of real-time detection.

To explain the paradox between the experimental and theoretical results of equivalent full charge (EFC) conversion coefficient, which can be used to convert the number of firing under various firing conditions to the number of EFC firing, a computational method of that coefficient is investigated on the basis of the thermo-chemical erosion model of the barrel. Supposing that the thickness and composition of the white layer on the inner wall of barrel change periodically after several firings, the relationship among the thermo-chemical erosion volume at the beginning of the rifling and the erosivity of the propellant and the transient temperature field of the inner layer of the barrel is established with the help of the mass diffusion law. During the firing process, the gas temperature in the space behind the projectile and the forced convection coefficient at the innerwall surface of barrel are provided by the classical interior ballistic theory. Hereafter, the model to calculate the transient temperature of the barrel can be developed. In addition, the effect of gas with relative high temperature during the after-effect period is also considered. Eventually, focusing on the firing rate, the charge mass and the charge temperature which have an essential effect on the interior ballistic process, erosion volumes under different firing rates, charge numbers and charge temperatures are calculated. Accordingly, the EFC conversion coefficients under various firing conditions are obtained. It is found that a more severe erosion of the barrel is often related to a faster firing rate, a more charge mass and a higher charge temperature.The EFC coefficient of the supercharge is up to 2.131. The reasonability of the proposed model is verified by using the practical firing data of a 155 mm barrel.

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.

The high-speed switching of switch modules in the high-power electric drive system of armored vehicle power system will generate a series of high-voltage transient pulses and broadband harmonic interference, thus posing a serious threat to the highly electrified vehicle system. A system level constructing method for a conducted interference prediction model is proposed to address the lack of digital detection and analysis of conducted interference generated by high-power electric drive systems. Firstly, the models of electrical components, such as high-voltage battery pack, inverter, and load motor, of the electric drive system are constructed independently; secondly, based on the multi-conductor transmission line method, each model is cascaded through transmission lines that characterize the parasitic effects of the system, thereby forming a complete distributed system-level conducted interference prediction model; and finally, the accuracy of the proposed prediction model is test and verified through bench test. The verified results indicate that the proposed prediction model has a simulation accuracy of better than 8 dB in the frequency range of 10 kHz to 100 MHz, which can provide effective support for the forward design of electromagnetic compatibility of electric drive armored vehicle, and is innovative and practical.