Abstract:Infrared selective radiator means that the object can effectively change the radiation characteristics of the target by regulating the distribution and amplitude of spectral emissivity through technical means. Due to the designable characteristics of radiation, such a material can be applied in energy, environment and military fields, and has a promising prospect and preferred. Firstly, this paper summarizes and classifies the design methods based on the researches of infrared selective radiators in recent years. Besides, this review introduces the design principles and related researches of selective radiator based on metamaterials, photonic crystals, and multilayers. The application scope and relative merits of the three methods are summarized. Lastly, the technical difficulties of infrared selective radiator development are summarized in three aspects: the evaluation system, engineering applications, and development trends. The suggestions and the outlooks for developments of infrared selective radiator are provided.

Abstract:Frequency Selective Surface (FSS) microwave transparent materials are the concentrated expression and successful practice of pursuing a structure-function integration of microwave transparent materials for a long time. With the increasing performance requirements of antennas and communication systems to omnibearing wave transmission, broadband wave transmission, frequency selective wave transmission, stealth, etc., this technology becomes a new hot spot in the research of microwave transparent materials, and has a wide range of applications in the fields of military and civilian products. A ceramic-based FSS microwave transparent material technology is proposed in accordance with the development of high-temperature and high-performance radome, which is of great significance to the sustainable development of microwave transparent material technology. This paper analyzes the current research needs of ceramic-based FSS microwave transparent materials, introduces the current research status of domestic ceramic-based FSS microwave transparent materials, and prospects for its application prospects.

Abstract:Traditional meta-surfaces generally utilize propagation phase, geometric phase or their combinations for realizing manipulating scatterings of electromagnetic (EM) waves, and are mostly in the light of normal incidence. When incident EM waves become oblique, the performance of manipulating EM waves will become worse due to impedance mismatch, especially for large incidence angles. Fortunately, detour phase provides controlling obliquely incident EM waves with an alternative method, which can be introduced by moving meta-atoms from their original periodic lattices instead of changing the structure parameters or rotating the meta-atoms. This paper proposes a design strategy of independently manipulating EM waves under different incidence angles based on the combination of detour phase and geometric phase. As a proof-of-principle, a split ring resonator (SRR) is chosen as the meta-atom, which can achieve broadband polarization conversion. The meta-surface is formed by shifting and rotating the SRR meta-atoms to simultaneously introduce detour phase and geometric phase. When EM waves are incident normally upon the meta-surface, the scattered waves are split into two beams due to the geometric phase design. While under oblique incidence, most scattered waves are funneled into the -1st diffraction order and then are deflected by the detour phase design. Both the simulated and measured results show excellent performances. This method enriches the degree of freedom to manipulate EM waves using meta-surfaces and can be extended to full-space beam engineering by further combining with propagation phase, resonance phase, etc.

Abstract:A hybrid meta-surface for achieving microwave absorption is designed based on the tunability of graphene and passive metallic structure with specific response to utilize the metallic structure and the electric properties of graphene for controlling the wave absorption. Through simulating three-dimensional full-wave electromagnetic field, the results prove the simulation to be the fact that the absorption rate at the resonant frequency can be tuned by adding the bias voltage through the square resistance of graphene, a perfect-absorption is achieved at a resistance level of 740 Ω/sq, and the absorption frequency is determined by the polypropylene thickness. The hybrid meta-surface combined with metallic structure and microwave absorber is further constructed, the metallic structure with new resonant mode is designed to increase the operation band width of the microwave absorption. The perfect absorption can achieve at 23.2 and 36.4 GHz, and the these two frequencies defines a wide band microwave absorption. The influence of structural parameters on the absorptive rate and frequency is studied. The research on tunable absorption in hybrid meta-surface is of certain scientific value in meta-surface design and graphene related applications. Key words: graphene; meta-surface; microwave absorption

Abstract:A meta-material structure which is used to transform electromagnetic energy into a local temperature field is designed. The local electric field enhancement effect of metamaterials can generate strong electric fields and achieve the electromagnetic energy-thermal energy conversion. The electromagnetic wave energy is coupled to the surface of the meta-material through a way of wireless, collecting the wireless energy. The experiments show that the energy of electromagnetic wave can be localized in finite space as heat energy via reasonable structural design. The highest temperature of local temperature field enhancement can reach at 2010 . Through combining with thermo-material Bi2Te3,an energy collector which is used to convert the electromagnet energy into the electric energy is designed. The output voltage of a single structural unit is as high as 27 mV under an incident microwave of 7 W.

Abstract:In view of the problem of the static aero elastic divergence of forward-swept wings, based on plasma flow control and fluid-solid two-way interaction technology, the three-dimensional constant compressible N-S equation and structural static balance equation are solved. Under condition of subsonic velocity, the flow field with and without plasma actuation is calculated. The forward-swept wing being NACA0015 airfoil and the plasma actuation area being a phenomenological model, both of them are applied to the leading edge of the upper surface of the wing. The results show that when the plasma actuation is applied to the upper surface of the outer leading edge of the forward-swept wing the local incoming flow in the actuation region is excited, and the work is done by the electric field force. The total energy, the kinetic energy and the pressure potential energy increase to a different degree, whose external manifestation is that the local flow velocity on the upper surface increases and the pressure increases while the lift partly decreases, and the pressure on the lower surface remains basically unchanged. A bow moment is generated near the wing tip on the outside of the leading edge of the wing, which can control the elastic deformation of the forward swept wing. This effectively suppresses the static aero elastic divergence of the forward-swept wing ,and with the increment of excitation intensity, the suppression effect gradually increases. The results give a reference to the aero elastic design of the variable forward-swept wing aircraft and the flow control of the wing.

Abstract:Aimed at the problem that continuous detonation caused by the jet radial incidence focusing structure fails to successfully complete in the detonation model of 2-Stage PDE proposed by Levin et al,an efficient and rapid filling by changing the incident direction of annular jet is made based on the simulation conducted by FLUENT software.Through the use of high frequency and low energy consumption spark plug preignition tapered channel, annular narrow slot and annular curved surface, the annular detonation wave incidence is enhanced, and the shockwave focusing initiation can be realized in the concave cavity after diffraction the result shows that t single cycle time pf the concave cavity structure is 9.1 ms, the filling time is 7,6 ms, and the working frequency is 109 Hz.

Abstract:In view of the rise of temperature, and being bending fatigue to the composite material under ultra-high three-point, this paper utilizes the commercial software ABAQUS for modeling and simulating the thermal effect in the experimental process, and the main heat generation stage and position of CFRP specimen under fatigue load are obtained, The ultrasonic fatigue test under continuous load is carried out by using composite cooling method. The results show that there is no traditional fatigue limit for CFRP. With the change of stress level, there is a damage competition mechanism in the ultra-high three-point bending fatigue failure of CFRP. The main damage morphology is a pit corrosion at low stress level, and delamination and transverse crack at high stress level.

Abstract:The scientific and reasonable selection of mission aircraft is an important support to ensure the success of the mission. In view of the characteristics of fuzzy evaluation and combinatorial optimization for multi-stage mission aircraft selection, based on the evaluation index system of mission aircraft combat fitness, the combat fitness of different mission subjects was evaluated based on intuitionistic fuzzy and group analytic hierarchy process (AHP). Then, based on the simulated annealing genetic algorithm, the aircraft selection for multi-phase mission system was realized with the target of combat adaptability of multi-phase mission system. The validity of the model method is verified by case analysis, which provides decision support for multi-phase mission aircraft selection in the first-line troops.

Abstract:The edge stress reduction is one of the crucial factors in the airfield concrete pavement thickness design. At present, in calculating the thickness of cement pavement, the load transfer effect of joints is of consideration by both China and the United States according to 25 per cent of reduction factor in stress, but this is quite different from the actual situation. Based on the field measurement, the variation characteristics of stress reduction under the influence of structure parameters and joint types are analyzed statistically. Besides, in consideration of the airfield concrete pavement structure characteristics in China, the finite element method is adopted to analyze the rules of stress reduction under the influence of pavement structural parameters and joint stiffness. The result shows that the stress reduction factor is closely related to pavement structures and joint types. Furthermore, compared with the base thickness and modulus, the reduction factor of edge stress is more sensitive to the changes of the slab thickness and the foundation reaction modulus, and increases with increment of the slab thickness and decreases with increment of the foundation reaction modulus. Moreover, with the increment of joint stiffness, the reduction factor presents an “S” growth trend and can be described by quadratic function. With the increment of the load transfer coefficient, the trend is approximately quadratic function. Finally, this paper gives the values of the stress reduction factor under different load transfer ability.

Abstract:Quantum sensing technology is to take photons, atoms and other quantum systems as the medium, and utilize quantum effect for achieving ultra-high-precision and sensitive physical quantity measurement to break through the standard quantum limit and bring about new opportunities for the breakthrough of the traditional navigation and positioning timing technology system based on the measurement of time and apace parameters. The quantum sensing changes the perception mechanism of navigation sensors in navigation systems, enables high-precision observation of space-time parameters, and utilizes the non-classical characteristics of quantum systems for achieving sage and reliable transmission and detection of navigation information, and enhancing navigation confrontation capabilities. As the main testing ground for quantum sensing technology, the quantum navigation technology is in the ascendant ,new navigation parameter quantum sensing technology and functional device are constantly emerging, and the measurement performance is changing with each passing day, this paper analyzes the physical principles of different quantum sensing technologies and devices, discusses the development direction and research progress of quantum navigation technology ,and looks forward to its future development rends and combined navigation methods. With the advancement of quantum sensing technology, high-precision, anti-jamming and practical high-performance quantum navigation systems will have broad application prospects in the social, economic, and military fields.

Abstract:This paper proposes a shadow detection algorithm based on SLIC0 superpixel segmentation to address the issues of single-image shadow detection. Firstly, SLIC0 superpixels is used to segment the shadow image to generate superpixel blocks to detect the shadow contour. Then proposes a fusion-characteristics-based SVM classifiers, the superpixel blocks are classified and merged to detect the shadow areas. Finally, the proposed algorithm is compared with Otsu threshold method and traditional SVM detection method. The experiment results verified the effectiveness of the proposed algorithm. The detection performances comparison of SSIM and PSNR indicates that the proposed algorithm obtains relative higher performances than the reference algorithms.

Abstract:Pre-planned close air support (PCAS) is a typical air force offensive operation style, which plays a pivotal role in modern war. It is of great significance to study the information flow process of PCAS for improving the combat effectiveness of PCAS. Aiming at the problem that it is difficult to model and analyze the combat process of PCAS, the super-network theory is introduced. Through studying the basic operation process of PCAS and the interaction between nodes in the combat network, the super-network model of information flow of PCAS with two layers and five networks is constructed. Then, the topological characteristics of PCAS information flow super-network nodes from four aspects of degree centrality, intermediate number, clustering coefficient and closeness centrality are analyzed. The key nodes of the network are obtained by the comprehensive evaluation method of the importance of multi-attribute decision nodes. Finally, the rationality and effectiveness of the super-network model and the multi-attribute decision making algorithm are verified through the network attack experiment, which provides a new idea for the research of operational information flow.

Abstract:The multiple-input multiple-output (MIMO) sin frequency diverse array (sin-FDA) radar has the ability to estimate the angle and range of targets and it is crucial to improve the accuracy of two-dimensional estimation. To increase the range-angle estimation accuracy of the sin-FDA-MIMO radar, time reversal (TR) technology is introduced to make full use of the spatial diversity of multipath propagation and improves the performance of range-angle estimation algorithm. At first, the receive signal model of the sin-FDA-MIMO is analyzed. Then, the receive signal model of the sin-FDA-MIMO is derived based on TR technology. The Capon and MUSIC algorithms are used to estimate both the range and angle of single target and two targets respectively for two kinds of signal receive models. Finally, the correctness of the conclusion is verified by simulation.

Abstract:In order to evaluate the effectiveness of the troop reconnaissance equipment scientifically, reasonably and intuitively, an evaluation method of the effectiveness of the troop reconnaissance equipment based on the improved radar chart method is proposed. First of all, according to the characteristics of the troop reconnaissance equipment in active service and the effectiveness of the equipment in use, an evaluation index system of the effectiveness of the reconnaissance equipment is established, and based on the linear scale transformation method, the effectiveness index of the above reconnaissance equipment is normalized. Secondly, the index scale method is utilized for determining the weight of effectiveness evaluation index of reconnaissance equipment, solving the problem of inaccurate weight calculation of other weight scale method. Then, , the improved radar chart method is utilized for solving the problem that the evaluation result is not unique because of the inconsistent evaluation index sequence. . Finally, an example is given to verify the correctness and rationality of the proposed model.