Yunlong, China
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Zhang D.,PLA University of Science and Technology | Li F.,PLA University of Science and Technology | Zhao Q.,PLA University of Science and Technology | Zhao Q.,Nanjing University of Technology | Duan Y.,Engineer Academy of PLA
Advances in Structural Engineering | Year: 2016

For emergency purposes, a lightweight space truss bridge was designed. The bridge is composed of twin triangular deck-truss beams incorporating new structural forms and advanced fiber-reinforced polymer profiles. As a new structure, the structural properties of its triangular deck-truss beam have been studied in detail; however, a design-oriented study facilitating the application of the entire twin-trackway bridge under pure torsion remains to be undertaken. The objective of this article is to analytically explore the torsional mechanism of the twin-trackway bridge, which is characterized by torsional angle and torsional stiffness. To verify the derivation procedures and formulae, the pure torsion test and numerical analysis are conducted on a full-scale specimen. The results indicate that the analytical solutions compare well with the experimental and numerical results. The torsional moment is primarily resisted by the vertical bending of twin triangular deck-truss beams. The simplified analytical model can be used with sufficient accuracy for the design of the bridge. © The Author(s) 2016.

Zhang Y.,PLA University of Science and Technology | Kan C.,PLA Zhenjiang Watercraft Academy | Zhang L.,Engineer Academy of PLA
International Conference on Communication Technology Proceedings, ICCT | Year: 2015

In this paper, we investigate the problem of global optimization for distributed carrier aggregation (CA) in LTE with unlicensed spectrum, using a game theoretic solution. To cope with the local influences and the distinct cost of different CA types, we propose a non-cooperation game which is proved as an exact potential game. Furthermore, we propose a concurrent log-linear learning based uncoupled algorithm to converge towards NE of the game. In this algorithm, concurrent learning is introduced to accelerate the convergence speed. It is shown that with the proposed game-Theoretic approach, global optimization is achieved without exchanging information. Simulation results validate the effectiveness of the proposed game-Theoretic CA approach. © 2015 IEEE.

Xu C.,PLA University of Science and Technology | Deng Z.,PLA University of Science and Technology | Xiong R.,Engineer Academy of PLA | Deng F.,PLA University of Science and Technology
International Journal of Applied Electromagnetics and Mechanics | Year: 2015

When using sub-cell algorithms to model the coupling of apertures with finite depth in the finite-difference timedomain (FDTD) method, time-step size is required to be reduced to avoid instability. In this work, a time-step program is proposed for the stable modeling of apertures with finite depth using sub-cell algorithms. A sub-cell area related time-step reduction coefficient is introduced to ease the steady reduction of the time-step size firstly. Then a modified algorithm is given for sub-cells whose area is extremely distorted. Numerical results demonstrate that the proposed time-step program is an accurate and stable modeling of aperture coupling without resulting in significant time-step reduction. © 2015 - IOS Press and the authors. All rights reserved.

Chen Q.,PLA University of Science and Technology | Chen B.,PLA University of Science and Technology | Chen P.F.,Nanjing University | Yi Y.,PLA University of Science and Technology | And 2 more authors.
Physics of Plasmas | Year: 2015

Bow shock structures are important to various hydrodynamics and magnetohydrodynamics (MHD) phenomena in geophysics and astrophysics. The formation and propagation of bow shocks around the lightning return stroke channel are investigated based on the self-similar motion theory and simulated with a two-dimensional Eulerian finite volume resistive radiation MHD code. In this framework, as verification of theoretical models, the evolving structures of many quantities, such as the plasma density, temperature, pressure, shock velocity, and magnetic field, can be obtained, which present all the characteristics of bow shocks in the lightning return stroke processes. The evolution characteristics and the configuration of the curved return stroke channels, e.g., the non-ideal effects and the scaling laws, are discussed in detail. The results may have applications for some observed features of the return stroke channels and other phenomena in the lightning discharge plasmas. © 2015 AIP Publishing LLC.

Zhang N.Y.,Engineer Academy of PLA | Li X.Q.,Engineer Academy of PLA | Qu L.Y.,PLA University of Science and Technology
Advanced Materials Research | Year: 2014

Plant camouflage is one of the camouflage methods, which is conducted by using of planting and collecting plant and changing color of plant to conceal targets. It can be used to camouflage relatively big permanent fixed targets in peace time and also to camouflage relatively big permanent fixed targets in peace time and also to camouflage relatively small fixed or moving targets. However, in recent years, with the natural disasters occurring alternately, plant camouflage can be destroyed easily, and it is difficult to rebuild in a short time. To improve the effect of plant camouflage, more fertilizers are required, which may become an environmental hazard, unless adequate technical and socioeconomic impacts are addressed. A multifunctional slow-release nitrogen fertilizer has been developed to improve fertilizer use efficiency and reduce environmental pollution. In this paper, a series of slow-release formulations of nitrogen fertilizer were developed on the basis of natural attapulgite clay, ethylcellulose film, and sodium carboxymethylcellulose/hydroxylethylcellulose hydrogel. The structural of the product were examined. The slow-release profiles of ammonium chloride, ammonium sulfate, and urea as nitrogen fertilizer substrates were determined in soil. © (2014) Trans Tech Publications, Switzerland.

Xiong R.,PLA University of Science and Technology | Xiong R.,Engineer Academy of PLA | Gao C.,PLA University of Science and Technology | Chen B.,PLA University of Science and Technology | And 2 more authors.
IEEE Antennas and Propagation Magazine | Year: 2014

A uniform two-step method is proposed for the Finite-Difference Time-Domain (FDTD) analyses of the coupling of both long and short apertures with zero or finite depth. The aperture-field singularity is first studied in the form of the field distribution and the aperture coefficients derived from the numerical integral of the related fields. The dramatic field singularity and the coefficients are mainly determined by the aperture's width and depth, and also by the aperture's end-edge effect. To provide an accurate modeling of the aperture without requiring huge computational-resource usage, a high-resolution standard FDTD simulation of the aperture end-edge area is used at the first step, and then the electromagnetic field singularity is used to derive the aperture coefficients from a numerical integral. At the second step, the coefficients are fully included into the contour-path laws to derive the FDTD updating equations for the fields near the aperture. Numerical results validated that the proposed method is an efficient simulation of the aperture coupling. © 1990-2011 IEEE.

Xiong R.,Engineer Academy of PLA | Xiong R.,PLA University of Science and Technology | Chen B.,PLA University of Science and Technology | Wang Z.J.,PLA University of Science and Technology
Applied Mechanics and Materials | Year: 2014

In this paper, electromagnetic field distribution adjacent to the aperture is analyzed to help deducing the coupling principle of apertures. The aperture is located on an infinite plate to avoid the effect of other structures. Taking advantage of high-resolution standard finite-difference time-domain (FDTD) simulation, it is possible to observe the electromagnetic field distribution adjacent to the aperture. From analyses, it can be seen that the electromagnetic field component is dramatically varied adjacent to the aperture, and conclusions drawn here is helpful to deduce the coupling principle of apertures. © (2014) Trans Tech Publications, Switzerland.

Shasha D.,Engineer Academy Of PLA | Xiaomin S.,Engineer Academy Of PLA | Mei Z.,Engineer Academy Of PLA
BioTechnology: An Indian Journal | Year: 2013

Lane detection is important for the lane departure warning (LDW) for advanced driver assistance systems (ADAS). Several approaches for lane detection were suggested in the past. However, robustness is still an issue, in case the markings are not arranged in a straight line or when they are occluded. This paper presents a robust vision-based lane detection method. The key idea is to apply methods from the target tracking domain to identify lanes in the image space; we use an Interacting Multiple Model (IMM) approach to increase robustness. Our method is based on two phases: a preprocessing phase to extract areas that potentially represent markings and a tracking phase to identify the lanes. In the preprocessing phase, we use regions of interest, median filtering, Otsu?s algorithm, and image erosion. The tracking is performed in spatial dimension and based on the Interacting Multiple Model (IMM) approach to estimate the lane pixel positions in the image. Two models are used: one for straight lines and one for curves. The simulation results show that this method has good robustness under various road scenarios. © 2013 Trade Science Inc.

Zhang N.Y.,Engineer Academy of PLA | Yu J.,Engineer Academy of PLA | Zhang J.,Engineer Academy of PLA
Advanced Materials Research | Year: 2014

Objectives, which is motional on the batter field, such as vehicles, tanks, planes, warships, firing cannons, etc. They are all active objects. On the surface of these objects there have very higher temperatures than around background, they have special pictures, and are easy found by thermal infrared reconnaissance systems. In this study, itaconic acid (IA) was co-polymerized with N, N-diethylacrylamide (DEA) monomer to improve the swelling behavior and the total absorbing water. These copolymer materials were prepared by changing the initial DEA/IA molar ratio and total monomer concentration. The chemical structure of materials was characterized by fourier transform infrared (FTIR) spectroscopy. In comparison with the PDEA hydrogel, the equilibrium swelling ratio (ESR) of the materials increase with the increase of IA content in the feed and the swelling dynamics behaviors of the different composition ratios of the P(DEA-co-IA) materials on the different temperatures was investigated in detail. Using the big hot-inertia of water, the superabsorbent material of the object surface is propitious to debase the object temperature, which suggests that these materials have potential application as thermal infrared camouflage materials. © (2014) Trans Tech Publications, Switzerland.

Yao Y.,Engineer Academy of PLA | Pei G.H.,Engineer Academy of PLA | Liu B.,Engineer Academy of PLA | Wang Y.B.,Engineer Academy of PLA
Advanced Materials Research | Year: 2014

With the continuous development of science and technology, the computer simulation technique has been applied into many aspects of water conservancy public practice. A brief introduction, advantages and implementation process of the computer simulation technique were summarized in the paper. An optimal construction scheme was obtained on the analysis and comparing of the simulation results on the basis of the application of the computer simulation techniques in water conservancy construction. © (2014) Trans Tech Publications, Switzerland.

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