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To improve stiffness and strength of the deployable antenna truss and to keep the total weight and volume from increasing as caliber increases, this paper presents a new kind of deployable antenna truss with double-ring composed of hexahedrons. Numerical simulation was made by self-programming software and a scaled model of 4.2-meter diameter was designed and manufactured, which demonstrate the developability of double-ring deployable antenna truss. In addition, frequency analysis and experiment was taken to make sure of stiffness of the truss.

Aluminum substitution in CuInSe2could have important implications for photovoltaic applications. To better understand the Al doping effects, we have performed density functional calculations on the CuInSe2chalcopyrite as well as on Al-doped derivative compounds with different concentrations using the generalized gradient approximation. The structural and electronic properties of the pure and Al-doped CuInSe2have been calculated. We find that the substitution of In by Al creates structural deformation, and the band gap of CuIn1-xAlxSe2broadens as Al content increases. These are further discussed with the analysis of lattice parameters, bond lengths and angles, and electronic structures changes.

Based on density functional theory (DFT) within the framework of the generalized gradient approximation method, we have studied the Cd1-xZnxS sphalerite crystal structure and optical properties. We calculated electronic and optical properties of Cd1-xZnxS at the doping concentration x = 0, 0.25, 0.50, 0.75, 1.0. Optical properties (reflectivity, absorption coefficient, refractive index, dielectric function) and the electrical properties (band structure, electron density, etc.) are obtained including Zn-doing effects on the crystal structure, optical properties and electrical properties. With the increase of doping concentration x, the lattice parameter reduces from 0.5910 nm to 0.5409 nm; as a direct wide band gap semiconductor, its band gap increased from 1.15 to 2.22. Optical absorption coefficient increases with the increase of doping concentration, but the rate of increase is relatively small.

Through testing the errors of spur gear and helical gears, transmission error curve of non-grinding gear is drawn. The effect factors on gear transmission error are found. The transmission error effect factors of all kinds of gear high-low frequency are analyzed. It is obtained that gear kinematic error is the evaluating guideline of transmission precision. Experimental results shows that error of gear axial offset and gear frequency period have less effect on gear transmission kinematic error. While gear backlash and face width direction error have more obvious effect on kinematic error. The results provides reasonable theory basis for determining gear cutting precision.

In this paper, the advantages of smart materials and structures are introduced. Because of the influence of friction, it’s difficult to deploy the large ring truss antenna driving by cable. The SPMC hinge is added in the deployable joint, the deployable antenna is deployed by heating the material to cause recovery strain, which substitutes for the driving by cable. Describe the behavior of SPMC material, and do the simulation, from the analysis results, we can aim that the stress of SPMC satisfies the yielding stress when the node is furled. At the same time, the force to expand the antenna caused by heating SPMC is also obtained. Compared the different size of width, the variation of recovery force can be got.

The fuzzy clustering algorithm is sensitive to the m value and the degree of membership. Because of the deficiencies of traditional FCM clustering algorithm, we made specific improvement. Through the calculation of the value of m, the amendments of degree of membership to the discussion of issues, effectively compensate for the deficiencies of the traditional algorithm and achieve a relatively good clustering effect. Finally, through the analysis of temperature observation data of the three northeastern province of china in 2000, the reasonableness of the method is verified.

In this paper, microstructure and mechanical properties of the chafer cuticle were investigated. The microstructures of the chafer cuticle were first observed with a SEM. It showed that the cuticle is a kind of chitin-fiber-reinforced biocomposite with protein matrix. There are some holes existing in the chafer cuticle and the fibers around hole are continuous. Based on the observed results of the SEM, the analyses of 3D models on the simple composite elements with fiber-round hole were conducted. The result showed the microstructures of composite laminates with fiber-round holes can decrease the stress concentration and well transfer the stress. So it can improve the strength and toughness of the composite laminates included holes. These conclusions may present a bio-inspired approach for design and development of advanced man-made fiber-reinforced composites.