Military Fields Research Articles

Preparation of transparent AlON ceramics with controlled shapes by a novel spontaneous coagulation casting and pressureless sintering method

Aluminum oxynitride (AlON) exhibits excellent mechanical properties and good optical transparency in the ultraviolet to near-infrared range and can be used in military and civilian fields. However, the troublesome molding of AlON, especially for complex shapes, limits its promotion and application. Therefore, transparent AlON ceramics with complex morphologies were prepared for the first time by a novel spontaneous coagulation casting (SCC) and pressureless sintering method. In this study, we report a simple carbothermal reduction and nitridation (CRN) method for synthesizing high-purity AlON powder, which is especially suitable for wet casting without anti-hydration treatment. The dispersion and gelation behavior of AlON slurries by isobutene maleic anhydride copolymer (Isobam104) and tetramethylammonium hydroxide (TMAH) were extensively investigated. With the addition of 0.9 wt% Isobam104 and 15 mL/L TMAH, the AlON slurries can achieve a solids loading of up to 45 vol% with the lowest viscosity (460.4 mPa·s-10 r/min) and the AlON green body is free of cracks and deformation during drying and demolding processes. Finally, the AlON green bodies with square and polygonal irregular morphologies were fabricated via a simple SCC method. High transparent AlON ceramics of a maximum transmittance up to 77.3% at 2000 nm and 72.2% at 632 nm were obtained by pressureless sintered at 2000 °C for 6 h. The SCC method has great potential in preparing ceramics with controllable shapes.

Kolomenskij mashinostroitel'nyj zavod v gody Pervoj mirovoj vojny: proizvodstvo voennoj i grazhdanskoj produkcii

The article presents the peculiarities of the Kolomna Machine-Building Plant during the First World War. The process of expanding production is shown by increasing the production of steam locomotives for military field railways, medium-speed piston engines for navy ships and submarines, as well as new products for the enterprise - artillery shells, machines for the production of barbed wire, machine-gun carriages, marching infantry and artillery kitchens.

MXene/AlGaN van der Waals heterojunction self-powered photodetectors for deep ultraviolet communication

Self-powered deep ultraviolet (DUV) photodetectors (PDs) have attracted considerable attention in environmental, industrial, and military fields because of their power-independent and environmentally sensitive photodetection. However, DUV PDs based on traditional thin film structures are limited by the low intrinsic mobility of aluminum-gallium nitride (AlGaN) and the large barrier width of the heterogeneous structure, which makes it difficult to achieve efficient spontaneous separation, resulting in lower responsiveness and a slow response speed. Herein, a 2D/3D DUV PD based on the MXene, niobium carbide (Nb2CTx)/AlGaN van der Waals heterojunctions (vdWHs) has been proposed. The as-prepared DUV PDs revealed self-powered properties with a high responsivity of 101.85 mA W−1, as well as a fast response (rise/decay time of 21/22 ms) under 254 nm DUV illumination, thanks to the excellent electrical conductivity and tunable work function of the MXene. It also showed a large linear dynamic range of 70 dB under −2 V bias because of the strong DUV absorption of MXene/AlGaN vdWH, and the enhanced carrier mobility under high illumination density. This study presents an easy processing route to fabricate high-performance self-powered DUV PDs based on MXene/AlGaN vdWHs for DUV communication.

AI and the Future of War: The Impact of Machine Learning in Security Practice

This paper explores the relationship between artificial intelligence (AI) and future wars, and focuses on how machine learning strengthens safety practice. Based on Wu Qianze's paper in National Defense Science, Technology and Industry, Issue 5,2019, this paper expounds the wide application of AI in the military field and the great potential of machine learning in improving security protection. Through a review of existing studies, this paper presents a series of recommendations to enhance safety practices designed to provide guidance for future research and applications.

Kipchak Networks of Power in Mongol China

Kipchak tribes have always had an important military role in the Mongol Empire. In this article, a Kipchak tribe that was at the center of this military role and formed a strong social and political network in Mongolian China is discussed. In addition to their military roles and the social capital they use to strengthen their influence in the Mongolian civil bureaucracy in China, the functioning of their family structure and its benefits are shown. Accordingly, even the marriages of the members of the Kipchak tribe in question served to establish or expand their power networks. Local records of the Jiking Region in China, which hosted many prominent immigrants during the Yuan period, provide important evidence for this investigation. Tuq Tuq’a’s relatives and descendants, who took care to preserve their identity as an elite military unit until the end of the dynasty, both in the civil bureaucracy and in the military field, successfully maintained the position of Commander of the Imperial Guard; In addition, this important and powerful military clan gained significant property and financial advantages in the Jiking Region. This nomadic group that settled in China became an important part of the Yuan Dynasty.

Two birds with one stone: High electromagnetic interference shielding effectiveness and high thermal conductivity of ternary polyvinyl alcohol/graphene/ carbonyl iron nanocomposite films

Gaining brilliant flexible, easily-processable, bendable, low-density and high electrical conductivity (σ) materials with an excellent electromagnetic-interference (EMI) shielding performance is urgently needed in the fields of aerospace, aircraft, military, wearable and portable electronic industries. Therefore, the growing desire towards miniaturizing and developing high-frequency electronics is increasing incredibly today and grabbing much attention, however, they cause extreme heat accumulation and EM radiations that affect their performances as well as their hazardous effects on human health. So, polymer nanocomposites with high thermal conductivity (k) and EMI shielding effectiveness (SE) synchronously are urgently required to consume the generated heat and blocks the EM waves. Herein, poly(vinyl alcohol)/graphene nanosheets/carbonyl iron (PVA/GRx/CIR0.1-x) nanocomposite films are introduced as a new alternative candidate for EMI shielding applications with high in-plane k//, high mechanical functions, and EMI SET performance. The synergistic effect of GR and CIR on EMI shielding functions, thermal stability, mechanical properties, electrical features, and surface morphology has been explored. The increase in GR(x) amounts provides continuous GR layers and dense networks for conducting electrons and heats, provides the films with an admirable k// and total SE (SET) synchronously. Particularly, the PVA/GR0.08/CIR0.02 films have shown an σ of 1.72 Sm−1, a large SET of 32.94 dB and a specific SE (SSE/t) of 4365 dBcm2g−1 due to the mutual role (effect) of both high electrical conductive graphene and high magnetic carbonyl iron in cancelling the magnetic and electric fields of the incident EM waves. Moreover, the layered structure of GR endows films with a high k// of 3.62±0.11 W/(m·K), which is 14-fold larger than that of green PVA. The high compatibility and fine dispersion of GR/CIR fillers endow the films with a high Young modulus of 2.16 GPa, which is 7-fold larger than that of green PVA. This work suggests a novel and feasible scheme for producing high EMI shielding and high thermal conductive polymeric films, which will have huge prospects in advanced technology such as electromagnetic (microwave) interference shielding, wearable, biological, smart fabrics, military technologies and electronic equipments.

Multifunctional MXene/PEDOT:PSS-Based Phase Change Organohydrogels for Electromagnetic Interference Shielding and Medium-Low Temperature Infrared Stealth.

Electromagnetic interference (EMI) shielding and infrared stealth technologies are essential for military and civilian applications. However, it remains a significant challenge to integrate various functions efficiently into a material efficiently. Herein, a minimalist strategy to fabricate multifunctional phase change organohydrogels (PCOHs) was proposed, which were fabricated from polyacrylamide (PAM) organohydrogels, MXene/PEDOT:PSS hybrid fillers, and sodium sulfate decahydrate (Na2SO4·10H2O, SSD) via one-step photoinitiation strategies. PCOHs with a high enthalpy value (130.7 J/g) and encapsulation rate (98%) could adjust the temperature by triggering a phase change of SSD, which can hide infrared radiation to achieve medium-low temperature infrared stealth. In addition, the PCOH-based sensor has good strain sensing ability due to the incorporation of MXene/PEDOT:PSS and can precisely monitor human movement. Remarkably, benefiting from the electron conduction of the three-dimensional conductive network and the ion conduction of the hydrogel, the EMI shielding efficiency (k) of PCOHs can reach 99.99% even the filler content as low as 1.8 wt %. Additionally, EMI shielding, infrared stealth, and sensing-integrated PCOHs can be adhered to arbitrary targets due to their excellent flexibility and adaptability. This work offers a promising pathway for fabricating multifunctional phase change materials, which show great application prospects in military and civilian fields.

Learning scattering waves via coupling physics-informed neural networks and their convergence analysis

Time harmonic acoustic wave scattering problems modeled by the unbounded Helmholtz equations are widely used in medical and military fields. A fast and flexible solver for the Helmholtz equation is expected in engineering applications. Fortunately, data-driven neural network algorithms show extraordinary promise in scientific computing and artificial intelligence. We solve the Helmholtz equation by decomposing the equation into a coupling equation system that explicitly includes the real and imaginary parts of the solution. The real and imaginary parts are approximated by the different neural networks, respectively. The unbounded domain is reduced to a problem on a bounded domain via the Dirichlet-to-Neumann operator. Thus, a coupling physics-informed neural network (cPINN) is constructed. On the other hand, in exploring the convergence analysis for PINNs, we obtain the convergence results for cPINNs through the universal approximation and Sobolev space theory instead of using the neural tangent kernel theory. We prove that the cPINNs converge to the solution of the Helmholtz equation in H01 space as the number of neurons approaches infinity. Finally, we propose some numerical results.

Evaluation on Data Transmission in Wireless Sensor Networks Based on Computer Technology

Traditional network data transmission (DT) has certain limitations in terms of processing, storage, and communication capabilities. Moreover, DT is easily affected by the network environment, which can reduce the real-time performance of DT. In severe cases, network transmission failures, DT interruptions, and other issues may even occur. As a new network, wireless sensor networks (WSN) have been widely used in military, industrial, agricultural, medical and other fields. In this paper, WSN was regarded as an important research method, and in-depth research was carried out around the real-time and energy consumption (for the convenience of the following text, the abbreviation for energy consumption is EC) of WSN DT. This paper focused on the issues of real-time performance, EC, and real-time transmission. It balanced EC and improved real-time performance through the low energy adaptive clustering hierarchy (LEACH) protocol and the power-efficient gathering in sensor information systems (PEGASIS) protocol. The experimental results showed that the real-time rates of LEACH under single reaction nodes were 45.5% and 48.6%, respectively. The lowest and highest real-time rates of PEGASIS were 86.2% and 89.5%, respectively. The real-time rate of PEGASIS was much higher than that of LEACH, proving that the proposed PEGASIS had high real-time performance and reduced DT delay.

Fabrication of Metal–Organic Framework‐Derived LaCo/C‐Decorated Ti3C2Tx Composites with High Electromagnetic Wave Absorption

Thin‐thickness and lightweight electromagnetic wave (EMW) absorption materials are critically needed for stealth technology in the military stealth field. The special structure of a material is important for improving its good EMW absorption. Herein, a series of porous metal–organic framework‐derived LaCo/C‐decorated Ti3C2Tx (LaCo/C/Ti3C2Tx) composites are prepared by carbonization at high temperatures. Impressively, the minimum reflection loss of LaCo/C/Ti3C2Tx–2 is −47.72 dB at 10.26 GHz (thickness 2.3 mm), and the optimal effective absorption bandwidth is 5.45 GHz (thickness 1.9 mm). The excellent EMW absorption properties are due to multiple electromagnetic loss mechanisms, such as polarization loss, magnetic loss, and multiple reflections and scattering. This work provides a new route for the application of Ti3C2Tx‐based derivatives.

Multi-AUV coverage path planning algorithm using side-scan sonar for maritime search

Coverage search is widely applied in the maritime military and civilian fields. To improve search efficiency and detection accuracy, we propose an effective and rapid multi-autonomous underwater vehicle (AUV) coverage path planning (ER-MCPP) algorithm using side-scan sonar (SSS). First, the given search region was optimized and modeled using grid decomposition. Next, a Voronoi diagram was used to divide and allocate the regions according to the initial position of the AUV. Subsequently, based on the idea of guidance, navigation, and control (GNC), a coverage search algorithm for a single AUV was proposed, including a path planning method combining improved lawn mower and outward-spiral methods, an integrated navigation method based on Kalman filtering, and a path tracking method considering ocean currents. In addition, we proposed a fault-tolerant control method. When an AUV fails unexpectedly, the other AUVs can accomplish a coverage search for the region through cooperation. Simulation experiments were performed using the MATLAB software. The results demonstrate that the proposed algorithm is valid. Compared with other methods, our algorithm has better robustness, finds targets more rapidly, and has a higher search efficiency. The practicality of the proposed algorithm is verified through field tests.

A Sandwich Structural Filter Paper-AgNWs/MXene Composite for Superior Electromagnetic Interference Shielding.

A thin, lightweight and flexible electromagnetic interference (EMI) shielding paper composite is an urgent need for modern military confrontations. Herein, a sandwich-structured EMI shielding paper composite with an easy pavement consisting of a filter paper layer, middle AgNWs/MXene layer, and polyvinyl butyral (PVB) layer was constructed by vacuum-assisted filtration, spraying and air-drying. The middle AgNWs/MXene compound endowed the filter paper with excellent electrical conductivity (166 S cm-1) and the fabricated filter paper-AgNWs/MXene-PVB composite exhibits superior EMI shielding (30 dB) with a 141 μm thickness. Remarkably, the specific EMI shielding effectiveness (SSE/t) of the filter paper-AgNWs/MXene-PVB composite reached 13,000 dB cm2 g-1 within the X-band frequency range. This value represents one of the highest reported for cellulose-based EMI shielding materials. Therefore, our sandwich-structured filter paper composite with superior EMI shielding performance can be used in the medical and military fields.

Progress in Performance of AlGaN‐Based Ultraviolet Light Emitting Diodes

AbstractAlGaN‐based ultraviolet light‐emitting diodes (UV‐LEDs) have the advantages of mercury (Hg) pollution free, small size, high efficiency, and so on, and are widely used in military, medical, and industrial fields, which are considered to be the most promising alternative to the traditional Hg lamps. Great efforts are made over the past few decades to improve the device performance, thereby meeting the commercial production and application requirements of UV‐LEDs, which is always accompanied by a series of interesting physical topics. In this review, the recent research progress in performance of AlGaN‐based UV‐LEDs is summarized from the perspectives of electrical injection, electro‐optical conversion, and light extraction, which are responsible for the operation of devices. The detailed discussions include the major challenges, the corresponding technological breakthroughs, and also the outlook of material growth, energy band modulation, as well as device fabrication involved in UV‐LEDs, which are expected to be helpful for the thorough comprehension of device physics and further development of AlGaN‐based UV‐LEDs.

Multi-objective optimisation of heat transfer and structural strength of aero-piston air-cooled engine cylinder based on orthogonal test

Owing to their compact and lightweight structure, air-cooled aviation piston engines are used in general aviation, agriculture, and military fields. To address the kind of engine thermal load problem, this study used a horizontal four-cylinder four-stroke aviation piston air-cooled gasoline engine as the research object. Tested the engine cylinder temperature and pressure under calibrated power conditions, built a one-dimensional simulation model and a fluid–structure interaction simulation model. Four main structural parameters—fin thickness, fin spacing, fin length, and cylinder wall thickness—were considered as factors. Each factors have five levels to construct orthogonal tests to analyse their influence on the cylinder heat transfer and structural strength performance. A range analysis of the orthogonal test showed that the fin thickness had the most significant influence on the thermal stress, while the fin length most significantly influenced the temperature and cylinder hole deformation. A comprehensive frequency analysis method combining intuitive and range analyses is used to determine the optimal combination scheme, and the heat transfer and strength performance of the engine cylinder before and after optimization is compared. The results indicated that the fin thickness and length had the most influence on cylinder performance. After optimisation, the temperature decreased by 3.3 % from 198.3 ℃ to 191.8 ℃, while the thermal stress decreased by 21.9 % from 100.5 MPa to 78.5 MPa. In addition, the cylinder hole deformation decreased by 11 %, from 0.273 mm to 0.243 mm. These research results can provide a reference for the design and optimisation of heat fins of air-cooled aviation piston engines.

Analysis in Making Animation Movements Using Traditional Methods (Keyframe) and Motion Capture Methods

The keyframe method for making 3D animation movements is a traditional technique used by animators around the world to create certain animation movements based zon the 12 principles of animation. Meanwhile, motion capture is a motion recording technique used to describe the process of recording movements and interpreting these movements into a digital model. Motion capture itself is commonly used in the military, entertainment, sports, and other fields. In this study, we analyze the use of the two methods, the results of which can be used as a suggestion for the use of the two methods for the production of animated films. Three aspects were used to analyze the two methods, namely the number of keyframes, the level of refinement and detail, the final process and cleanup.
 Keywords: keyframe, motion capture

High-performance single crystal diamond pixel photodetector with nanosecond rise time for solar-blind imaging

Solar-blind ultraviolet imaging detector is widely applied in many commercial and military fields, such as missile warning, guidance, ultraviolet communication, biomedical analysis, and police reconnaissance. High-performance pixel photodetector is the core of imaging technology. Therefore, its construction attracts intensive attentions in recent years. In this work, 8 × 8 planar pixels were constructed on high quality single crystal diamond using ultraviolet direct writing lithography. A typical pixel photodetector in metal-semiconductor-metal (MSM) structure achieved outstanding photo-response properties of a low dark current of 10−13–10−12 A at 50 V, a high light-dark current switching ratio over 105), a high responsivity of 22.6 A/W, and a decent specific detectivity of 4.2 × 1014 Jones. Moreover, the detector has a fast response time of 13 ns. Additional optoelectronic studies demonstrate the strong homogeneity and repeatability of the photodetectors array, enabling it to serve as a reliable solar-blind imaging photodetector with high spatial resolution.

Digital model of automated unmanned aerial vehicle with edge computing application for railway reconnaissance

In the last decade, unmanned aerial vehicles have been widely used in various civil and military field operations. Most modern drones are manually controlled by an operator and require decision making, which requires experience gained through training, which is time consuming and expensive, and even with experienced operators, the human factor can never be excluded. In this paper, an algorithm for an automatic flight mode of unmanned aerial vehicles without an operator’s participation has been developed. The proposed algorithm has been considered in the military reconnaissance of railways using edge computing and computer vision approaches to recognise railroads and moving trains for simulated and real cases as well as send report data to the web platform. As a result, the head of the operation received information about the number of carriages and Global Positioning System coordinates of the recognised train to make the necessary decisions.

A planning method for chemical plume tracking and source localization with autonomous underwater vehicle

Underwater target detection technology is an important mean for the development and utilization of marine environment, which has important value in commercial and military fields, and is valued by more and more experts, scholars, and production technicians. A set of behavior-based autonomous underwater vehicle online task planning algorithm is proposed in this article, including the searching behavior based on changing Z-shape, tracking behavior based on an improved artificial potential field theory with likelihood map, rediscovering behavior, and source declare behavior. The proposed algorithm can improve the accuracy and success rate of autonomous underwater vehicle to the source positionficient. The physical experiment results verify the effectiveness of the proposed method.

ڕۆڵی دادوەرەکان لە بواری سیاسی و سەربازی و کارگێڕی لە هەرێمی جەزیرەی فوراتی (٣٣٤-٥٩٠ک/ ٩٤٥-١١٩٣ز )

In different times of the authorities of Jazira Fwrati Region, Judges have played sisignificantoles in political events and resolving conflicts. This role sometimes played b positively and sometimes negatively even profProfessionallynot his mission, however, he would involved and become a part of the city’s problem. From that aspect, usually, they advised the authorities and their speeches have been taken into account in the political and military fields. Often, they had been sent as diplomatic envoys to the Abbasid Caliphate or the authorities of the Islamic State. The judges were prrepresenthe new authority begin to work, the judges participated in giving the confidconfidencee authority. Moreover, they played in the administrative field and they have high administrative ranks at different ttimes in the Jazira Fwrati Region. They are the assistant of the authorities to organize the administration field because the judges except for the judge’sopposition have several administrative positions and can manage them successfully.

Concluded project of the Ministry of Education University-Industry Collaborative Education Program: Cultivation of the Technological Innovation Ability for Young Backbone Teachers

Artificial intelligence and other new technologies not only have a wide application prospect in civil field, but also have very important application value in national defense and military field, especially in electronic countermeasures. In order to adapt the teaching ability and scientific research and innovation ability of young backbone teachers to the development of new technology, with the help of the Ministry of Education industry-university cooperation and collaborative innovation platform, local superior companies and enterprises to adopt the school-enterprise cooperation mode of industry-education integration, carry out the training of young backbone teachers in technological innovation ability. This project can improve the team members' scientific research and innovation ability and professional teaching level, and achieve a virtuous circle of joint improvement of the level of teachers, scientific research ability and talent cultivation.