Military Fields Research Articles

Efficacy Of Transfluthrin Varies By Species And Placement In A Warm Temperate Mediterranean Environment

ABSTRACT Spatial repellents may protect personnel in delimited areas from incursion of vector or nuisance Diptera, such as mosquitoes and sand flies. We investigated the efficacy of resin diffusers impregnated with transfluthrin in protecting 2 simulated military field scenarios (partially opened tents and open bivouacs lacking shelter) from natural populations of Culex species mosquitoes and Phlebotomus species sand flies. Using a benchmark efficacy of 61% expected reduction from a recent literature survey, we found that transfluthrin protected bivouacs from sand flies (74.1% average reduction; P < 0.001, t(38) = 4.234) but not mosquitoes (13.1% mean reduction, not significant). However, treated tents were not sufficiently protected from sand flies (33.3% mean reduction, not significant), and mosquito numbers increased by an average of 89.3% (not significant). Spatial repellents such as transfluthrin can be highly effective, but efficacy may vary by species and placement, and they should be incorporated into integrated vector management with care.

Review of Progress in the Application of Polytetrafluoroethylene-Based Battery Separators.

Batteries have broad application prospects in the aerospace, military, automotive, and medical fields. The performance of the battery separator, a key component of rechargeable batteries, is inextricably linked to the quality of the batteries. The polytetrafluoroethylene (PTFE)-based membrane, in addition to PTFE's intrinsic properties of corrosion resistance and high temperature resistance, also possesses characteristics such as high porosity and high strength, making it an ideal substrate for the separator in current high-performance batteries, such as fuel cells (FC), all-vanadium redox liquid current batteries (VRBs), solid-state batteries (SSBs), and lithium-ion batteries (LIBs). This paper introduces the PTFE membrane's main preparation methods and application fields and outlines its advantages as a battery separator. It then comprehensively describes the status of PTFE-based battery separator applications, sums up the advantages and development prospects of PTFE-based battery separators, and looks forward to the important role and challenges PTFE-based battery separators will play in the future of rechargeable batteries and even in new energy equipment with even more harsh and complex electrolytes. In the future, PTFE-based battery separators will be used in rechargeable batteries and even in new energy devices with more severe and complex electrolytes, which will play an important role and challenge in providing a reference for the research on PTFE-based battery separators.

Airborne Multi-Channel Forward-Looking Radar Super-Resolution Imaging Using Improved Fast Iterative Interpolated Beamforming Algorithm

Radar forward-looking imaging is critical in many civil and military fields, such as aircraft landing, autonomous driving, and geological exploration. Although the super-resolution forward-looking imaging algorithm based on spectral estimation has the potential to discriminate multiple targets within the same beam, the estimation of the angle and magnitude of the targets are not accurate due to the influence of sidelobe leakage. This paper proposes a multi-channel super-resolution forward-looking imaging algorithm based on the improved Fast Iterative Interpolated Beamforming (FIIB) algorithm to solve the problem. First, the number of targets and the coarse estimates of angle and magnitude are obtained from the iterative adaptive approach (IAA). Then, the accurate estimates of angle and magnitude are achieved by the strategy of iterative interpolation and leakage subtraction in FIIB. Finally, a high-resolution forward-looking image is obtained through non-coherent accumulation. The simulation results of point targets and scenes show that the proposed algorithm can distinguish multiple targets in the same beam, effectively improve the azimuthal resolution of forward-looking imaging, and attain the accurate reconstruction of point targets and the contour reconstruction of extended targets.

Synthesis of a lightweight and dual-band (K and Ka-band) microwave absorber based on cobalt ferrite/mesoporous carbon nanocomposite for stealth technology

Mesoporous carbon has gained significant attention as microwave absorber owing to its lightweight, high surface area and dielectric loss. Herein, for better impedance matching, CoFe2O4/mesoporous-carbon hybrid nanocomposites were synthesized with different content of mesoporous-carbon via a facile hydrothermal method and systematically investigated their K and Ka-band microwave absorption properties. RAMAN analysis establishes the strong interaction amid CoFe2O4 and mesoporous-carbon. Magnetic study confirmed the ferromagnetic nature of the nanocomposite which is helpful for high frequency range absorbers. The CoFe2O4/MC-60 nanocomposite presents a reflection loss of −51 dB at 2.5 mm thickness with an effective absorption bandwidth of 4.2 GHz. The |Zin/Z0| value for this hybrid nanocomposite was closer to 1. The superb absorption properties can be ascribed to best impedance matching and the synergistic effect of the heterogeneous interfaces between CoFe2O4 nanoparticles and carbon. This work can advance the development of magnetic/carbon absorber for high speed communication and military fields.

Review of Surface Treatment Technology for Improving Wear Resistance of Magnesium Alloys

Background: As the lightest metal structural material in engineering, magnesium alloy has excellent mechanical properties, such as high specific strength, high specific stiffness, good damping performance, and good machinability. It is widely used in the fields of precision parts, automobiles, aerospace, and military. However, poor friction and wear performance are significant magnesium defects of the alloys, which make its use limited in some areas with high working conditions, so it is essential to improve the wear resistance of the magnesium alloy surface. Objective: The aim of this study was to summarize the technology of improving the wear resistance of magnesium alloy in recent year. The influence of different surface treatment technology for enhancing friction and wear properties was also analyzed, which could provide a reference for related scholars and researchers. Method: In this paper, the literature related to friction and wear properties of magnesium alloys in recent years were reviewed, the principles of various surface treatment technology of magnesium alloys were explained, and the advantages and disadvantages of each technology were analyzed. Results: Based on the literature analyses related to the wear resistance of magnesium alloys, the problems existing in the surface treatment technology for improving the wear resistance of magnesium alloys are summarized, and future development directions are put forward. Conclusion: Among the technologies to improve the wear resistance of magnesium alloys, the combination of various techniques can better meet the working demands. The environmentally friendly and efficient manner has a good prospect for development.

A Provably Secure and Lightweight Two-Factor Authentication Protocol for Wireless Sensor Network

Wireless Sensor Networks (WSNs) are rapidly being integrated into various fields, significantly impacting and facilitating many aspects of human life. However, the increasingly prominent security issues associated with WSNs have become a significant challenge. This paper provides an in-depth analysis of the security challenges faced by WSNs in resource constrained and open communication environments. As a key component of the Internet of Things (IoT), a WSN can perceive, collect and transmit physical environmental data in real-time, and is widely used in military, medical, agricultural and other fields. However, the insecurity of communication channels and unauthorized user access pose severe threats to network security and data integrity. To address these challenges, this paper proposes a provably secure two-factor authentication protocol. This protocol utilizes a Chebyshev chaotic map and a two-factor authentication mechanism, which not only enhances security in WSNs but also improves authentication efficiency. The protocol is validated through security proof and performance experiments, demonstrating excellent security, functionality and efficiency. This provides strong support for secure and efficient communication in WSNs across various application scenarios.

Pearl‐Inspired Colored Carbon Fibers with Electromagnetic Interference and Optical Camouflage Properties

Carbon fibers (CFs) are widely used in cutting‐edge and civilian fields due to their excellent comprehensive properties such as high strength and high modulus, superior corrosion and friction resistances, excellent thermal stability, light weight, and high electrical conductivity. However, their natural ultra‐black appearance is difficult to meet the aesthetic needs of today's civilian sector and the need for optical stealth in the military field. In addition, conventional coloring methods are difficult to effectively adhere to CF surfaces due to high crystallinity and highly inert surface caused by their graphite‐like structure. In this work, inspired by the nacre structural color of pearls, colored CFs with 1D photonic crystal structure are prepared by cyclically depositing amorphous (Al2O3 + TiO2) layers on the surface of carbon CFs through atomic layer deposition (ALD). The obtained CFs exhibit brilliant colors and excellent environmental durability in extreme environments. Moreover, the colored CFs also exhibit high EMI shielding effectiveness (45 dB) and optical stealth properties, which can be used in emerging optical devices and electromagnetic and optical stealth equipment.

Pyramid-like magnetic carbon composites device toward tunable and adaptive radar-visible compatible properties

Equipped with intelligent adjustable electromagnetic-visible light compatibility characteristics is of significant importance in military stealth fields. In this work, a tunable microwave absorption and visible light change metamaterial based on polylactic acid (PLA) thermal stimulation was fabricated using 4D printing technology with hydroxylated carbon nanotubes (CNTOH) and carbonyl iron powder (CIP) as active ingredients. The printing filament was synthesized, which exhibited excellent absorption performance with a bandwidth of 5.83 GHz and sufficient shape recovery ability. On this basis, a temperature-dominated shape memory variation cone device was also manufactured and the visible light color-changing coating was sprayed. The microwave absorption performance is adjusted according to the petal angle, achieving a bandwidth variation of 5.9–9.8 GHz. This work confirms the potential exploratory value of the designed shape memory polymer in the field of microwave absorption, and provides unlimited possibilities for designing intelligent controlled stealth materials.

Research on UAV formation signal location based on two-dimensional plane analysis

In recent years, the UAV technology has developed rapidly and is widely used in military, civil and scientific research fields. In order to avoid external electromagnetic interference, the bearings-only passive positioning method is usually used to adjust the position of the UAV to maintain the formation.In this study, according to the circular formation of Uavs, the positioning model of the received signal of Uavs on the excellent arc and the positioning model of the received signal of Uavs on the inferior arc are established. The Uavs with slightly deviated positions in the circular formation are effectively adjusted, and the positioning model of Uavs with the passive receiving signal is established. In this paper, the double-station cross-positioning method is used to calculate that in the case of circular formation, four Uavs are needed to transmit signals, among which one is located in the center of the circle and the other three are distributed on the circumference to realize the effective positioning of Uavs.

Methodological Approaches in Military Science Research

Scientific research is a prerequisite for progress in all areas of society, and military science is no exception. However, its specificities require careful analysis in order to identify specific methodological approaches to ensure the added value of the results obtained. Moreover, the need for continuous transformation and adaptation of military structures to the operating environment and to the specific characteristics of contemporary armed conflicts leads to an increased interest in identifying innovative solutions in this field. Academic research is the approach to provide feasible and viable solutions to these challenges. However, there are relatively few works that address the methodological peculiarities specific to the field of military science. For this reason, the present article analyses how to organize and conduct scientific studies in the military field, proposing a structured framework of methodological approach in 14 steps to ensure the logical coherence of the approach, while highlighting the specificities of the field under analysis.

Utilization of registers to create an evidence-based approach in catastrophes and civil defence

Medical data registers are a key instrument of medical care research and a valuable tool for medical quality assurance. The structured plausibility tested documentation of large case numbers on a longitudinally oriented time axis with different points in time of data acquisition enables statements to be made on numerous relevant outcomes, not only the mortality of patients. For incidents outside the daily routine care in trauma surgery, such as natural disasters, accidents with multiple casualties and nonmilitary treatment of the domestic population in defence situations, such registers can provide data-based recommendations for action. These data, mainly obtained from routine traumatological treatment, enable a targeted resource management in the abovenamed incidents, which are associated with mass casualties. Due to the utilization of registers from the military field or from international registers, the perspective is additionally extended with respect to treatment strategies and injury patterns. Whether data can also be generated in a suitable manner for the abovenamed registers in specific disaster situations and can provide a direct gain of knowledge from the incident, must be critically discussed. The maintenance of the register datasets is time-consuming and has been subjected to a more stringent regulation at least since May 2018, when the European Union General Data Protection Regulation (EU-GDPR) came into force. The future Register Act in Germany will hopefully achieve greater simplification in the documentation of routine data.

A color image encryption algorithm based on a novel 4D hyperchaotic system and bit-level diffusion

As digital images are widely used in social media, medical, military and other fields, ensuring the privacy and security of image data has become a critical concern. Firstly, we propose a novel four-dimensional hyperchaotic system and validate that it exhibits a broad chaotic range, as demonstrated by bifurcation diagrams and Lyapunov exponent experiments. Additionally, simulated circuit diagrams verify the hardware feasibility of the proposed system. Secondly, we design a dynamic iterative scrambling (DIS) scheme that dynamically divides the image into multiple matrices for spatially indexed scrambling. Excellent substitution performance can be ensured by multiple iterations. In the diffusion stage, a multidirectional bit-level L-shaped (MDBL) scheme is proposed. Diffusion is conducted on the bit plane using a designed cross-multiplanar selection algorithm, which fuses the high and low bit planes, thereby enhancing the diffusion performance of MDBL. Thirdly, Based on the above concepts, a novel four-dimensional hyperchaotic system and an encryption algorithm based on bit-level diffusion are proposed. Finally, experimental results and security analyses demonstrate the effectiveness of the novel 4D hyperchaotic system and image encryption scheme. The proposed encryption scheme exhibits robust anti-interference capabilities and effectively safeguards image security.

Electromagnetic Interference Shielding Films: Structure Design and Prospects.

The popularity of portable and wearable flexible electronic devices, coupled with the rapid advancements in military field, requires electromagnetic interference (EMI) shielding materials with lightweight, thin, and flexible characteristics, which are incomparable for traditional EMI shielding materials. The film materials can fulfill the above requirements, making them among the most promising EMI shielding materials for next-generation electronic devices. Meticulously controlling structure of composite film materials while optimizing the electromagnetic parameters of the constructed components can effectively dissipate and transform electromagnetic wave energy. Herein, the review systematically outlines high-performance EMI shielding composite films through structural design strategies, including homogeneous structure, layered structure, and porous structure. The attenuation mechanism of EMI shielding materials and the evaluation (Schelkunoff theory and calculation theory) of EMI shielding performance are introduced in detail. Moreover, the effect of structure attributes and electromagnetic properties of composite films on the EMI shielding performance is analyzed, while summarizing design criteria and elucidating the relevant EMI shielding mechanism. Finally, the future challenges and potential application prospects of EMI shielding composite films are prospected. This review provides crucial guidance for the construction of advanced EMI shielding films tailored for highly customized and personalized electronic devices in the future.

Rapid synthesis and enhanced microwave absorption of carbon-supported high-entropy metal oxide

Complex preparation process and long annealing time of high-entropy metal oxide (HEO) limit its extensive application as microwave absorber at civil and military fields. Herein, a rapid synthesis method of mesocarbon microbeads (MCMB)-loaded spinel structure (FeCoCrNiMnCu)O is studied via plasma flow. In the presence of extreme plasma heating rate, a nanoscale high-entropy phase can be formed while modifying the surface activity of carbon. Simultaneously, due to the short synthesis time, gaseous conversion of carbon under high temperature aerobic conditions is avoided. By appending of carbon, the dual-media absorber exhibits better absorption performance with a maximum peak (-44.7 dB), which achieves over 90 % absorption in 11.2–15.5 GHz with a thickness of only 1.9 mm. Interestingly, the real and imaginary parts of complex permittivity increase remarkably. The former change is attributed to the expansion of heterogeneous hole carrier region and the latter dues to the interfacial polarization of the strongly coupled interface. The increase of dielectric loss and conductance loss leads to great improvement of microwave absorption. Our study injects new vitality into the preparation of HEO for advanced applications and the as-prepared HEOM is promised to be high-efficient microwave absorber based on robust stability and excellent absorbing performance.

Data-Driven Fault Detection and Diagnosis for UAV Swarm Systems

With the widely application and promotion of Unmanned aerial vehicle (UAV) technology, UAV swarms are widely used in military and civilian fields by taking advantage of group collaboration. It has huge economic and national defense value. The safety and reliability requirements of the UAV swarm system are extremely strict, and real-time fault detection and diagnosis is one of its important supporting technologies. In this paper, a fault diagnosis method based on statistical model and improved broad learning system (BLS) is proposed. The behavior characteristics of the UAV swarm system under normal and different failure modes are characterized by multivariate data statistical analysis, and the improved BLS model is adopted to achieve accurate and fast fault diagnosis. And a high-fidelity simulation verification platform is developed to verify the rationality and effectiveness of the proposed method.

Design of Underwater Cables Applicable to Submarine(KSS-III Batch-II) Navigation Radar

Since the creation of the first submarine telegraph cable connecting England and France in 1850, today, due to the rapid development of the Internet and Communications fields, the demand for submarine communication cables has increased and continues to develop. Submarine cables are designed and manufactured to be suitable for the maritime environment, and many parts are imported from overseas, and several domestic cable manufacturers are producing them for commercial purposes. Field-proven and reliable commercial submarine communication cable technology is also being applied to the military field, and is especially actively utilized in naval surface ships and submarines. This paper is about the design of an underwater cable applicable to submarine(KSS-III Bach-II) navigation radar and also is to secure the performance of an underwater cable with bending durability in extreme marine environments, emergency diving, and repeated mast raising and lowering. Finally, we hop that the domestic development of underwater cables will help improve the performance of navigation radars for submarines.

Distributed multi-sensor multi-target tracking with fault detection and exclusion using belief propagation

Multi-sensor multi-target tracking (MMT) is widely used in civilian and military fields. However, as the number of sensor nodes increases, so does the probability of the sensor node faults corrupting the system. In order to guarantee the tracking performance in the presence of faulty sensors, a distributed MMT algorithm in clutter with sensor fault detection and exclusion under the belief propagation framework (FDE-BP) is proposed in this paper. Firstly, a novel FDE method using the fused residual is proposed to detect the faulty sensors in clutter. To ensure the independence among the fused residuals of different targets, a measurement partition method based on the assignment matrix is proposed. The partition of measurements makes the factor graph have a tree structure rather than a loop one, which reduces the computational complexity. Secondly, the MMT problem is presented by a factor graph model to fuse the information among distributed sensor nodes, and a Gaussian version of FDE-BP is derived. The simulation results show that the proposed FDE-BP algorithm can guarantee the tracking performance in the presence of different types of sensor faults.

A linear shaped charge cutting model for brittle flat plates

The dynamic response and damage fracture of brittle materials under explosive cutting have always been important research issues in the fields of military, aerospace, and other engineering fields. In this paper, a linear shaped charge cutting model for explosive cutting of brittle materials is proposed. This model suggests that explosive cutting is caused by the combined effects of jet penetration, spallation, and impact fracture. Theoretical calculation models for jet penetration, spallation, and impact fracture were constructed, and the concept of impact strength was introduced to establish dynamic mechanical performance parameters for brittle materials. A calculation program for explosive cutting of brittle materials was developed using the Python language, which can calculate the jet penetration depth, spallation thickness, and impact fracture thickness by inputting parameters such as the size and mechanical properties of the linear shaped charge and target plate, and determine whether the target plate can be successfully cut. Subsequently, a series of explosion cutting experiments and numerical simulations for brittle target plates were conducted to verify the accuracy of the calculation program. The results indicate a high degree of consistency between simulation, experimentation, and program calculation results. This work can provide guidance and promotion for the design and application of explosive energy harvesting cutters.

Gain improvement of conformal circularly polarized Fabry-Perot resonator antenna based on metasurface

Conformal antenna can keep consistent with the shape of the carrier perfectly, which greatly saves the space of the carrier, so it is widely used in military, aerospace and other fields. In this paper, a cylindrical conformal circular polarization Fabry-Perot resonator antenna is designed, and the adverse effect of conformal on antenna gain is overcome by transmission phase compensation. Firstly, a linear to circular polarization conversion metasurface with adjustable transmission phase is designed. The main reason for choosing the metasurface here is to take advantage of its excellent electromagnetic control ability. The metal structures of the metasurface are printed on the ultra-thin dielectric plates, and then attached to the support structure machined by 3D printing, so as to achieve the conformal design of the metasurface. Secondly, the proposed metasurface is used as the superstructure and is combined with a conformal feed to form a cylindrical conformal circularly polarized Fabry Perot resonator antenna. The conformal feed is a patch antenna which is conformal designed in the same way as the metasurface. The conformal feeder is placed under the conformal metasurface to ensure that the electromagnetic wave radiated by the feeder can enter the resonant cavity composed of the feeder and the metasurface. The curvature of the cylindrical conformal of feed and metasurface is the same, which can ensure the high unity of the different positions in the resonator. Next, by adjusting the transmission phase of the unit on the metaurface, the phase compensation of the transmitted electromagnetic wave is realized, so that the electromagnetic wave radiated by the conformal antenna still presents the characteristic of plane wave. Finally, the conformal Fabry-Perot resonator antenna obtains the same high-gain radiation characteristics as the planar resonator antenna. The designed antenna achieves a maximum gain of 13.1dBic at 10 GHz. The size of the antenna is 2.9λ × 2.9λ, so the aperture efficiency is about 19.9 %. The antenna proposed in this paper overcomes the influence of conformal design on the gain of the antenna, so that it can be conformal on the surface of a cylindrical object and obtain better gain characteristics.

A Nd-doped silica glass with high doping concentration, low hydroxyl content, and 900 nm fluorescence emission fabricated by laser additive manufacturing

The 900 nm wavelength laser is effective for atmospheric detection and various other applications.The frequency-doubled 450 nm deep blue laser can be used in maritime military, quantum optics, biomedicine, laser storage, laser display, and deep ultraviolet laser fields, among others. Although Nd3+ is considered the optimal medium for generating 900 nm lasers, competition with the 1060 nm emission wavelength must be addressed. In Nd-doped silica glass, without the introduction of aluminum, the emission intensity of the three-level transition is higher than that of the four-level transition. However, it can cause a concentration quenching between Nd3+, but co-doping with Al can effectively suppress it. As the Al/Nd ratio increases, the emission intensity at 1060 nm increases relative to that at 900 nm. By precisely adjusting the Al/Nd ratio, it is possible to suppress the 1060 nm emission while also inhibiting concentration quenching caused by Nd3+.