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101.
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成钢 《武汉理工大学学报(材料科学英文版)》2013,28(4):840-843
The effects of Dy on the microstructure and magnetic properties of Dy x Co50?x Pt50 alloys were investigated. The XRD results indicate that all the alloys homogenized at 1000 °C contain only a single A1 (fcc) phase, while the alloys annealed at 675 °C consist of a hard-magnetic face-centered-tetragonal (fct) phase and a magnetically soft face-centered-cube (fcc) phase. Maximum values for the coercivity H c and remanence ratio m r were achieved in Dy0.4Co49.6Pt50 alloys annealed at 675 °C for 80 min. For the series of Dy x Co50?x Pt50 alloys annealed at 675 °C for 60 min, H c decreases monotonically with increasing Dy concentration, but m r is first enhanced and then weakened. 相似文献
103.
Effect of fiber orientation on the structural behavior of FRP wrapped concrete cylinders 总被引:1,自引:0,他引:1
Guoqiang Li Dinesh Maricherla Kumar Singh Su-Seng Pang Manu John 《Composite Structures》2006,74(4):475-483
In this study, 27 concrete cylinders with a diameter of 152.4 and a height of 304.8 mm were prepared. Among them, 18 cylinders were wrapped using two layers of fiber reinforced polymer (FRP) with six fiber orientations; six cylinders were wrapped using four layers of FRP with fibers in axial or hoop direction only; the remaining three cylinders were used as control. The FRP used was E-glass fiber reinforced ultraviolet (UV) curing vinyl ester. Fifteen coupon specimens were prepared to experimentally determine the tensile strength of the FRP with fibers oriented at 0°, 45°, and 90° from the loading direction. Co-axial compression tests were conducted on the wrapped cylinders and control cylinders. The test results were compared with existing confinement models. It is found that the strength, ductility, and failure mode of FRP wrapped concrete cylinders depend on the fiber orientation and wall thickness. Fibers oriented at a certain angle in between the hoop direction and axial direction may result in strength lower than fibers along hoop or axial direction. A larger database is desired in order to refine the existing design-oriented confinement models. 相似文献
104.
Yuqi Wang K.H. Low H.L.J. Pang K.H. Hoon F.X. Che Y.S. Yong 《Microelectronics Reliability》2006,46(2-4):558-573
Multi-layered printed circuit boards (PCBs) contain a multi-layered structure that is suitable for high-speed and high-frequency applications. Hence, they are used extensively in electronic packaging assemblies for high-density applications. However, numerous composite parts and complex material properties of multi-layer PCBs complicate the reliability simulation of PCB model. This paper deals with a finite element analysis intended to describe numerically the behavior of multi-layered multi-materials PCB model (combination of metallic and composite plies) in the drop-impact performance. Through the comparison of physical drop test results, the fully multi-layered model illustrates higher accuracy if compared with that of the traditional simplified isotropic model and orthotropic model. The effects of material properties for the multi-layer PCB under drop-impact shock have also been investigated. 相似文献
105.
Voice over wireless local area network 总被引:1,自引:0,他引:1
This paper introduces the special issue on voice over wireless local area networks (VoWLAN), which aim to foster interaction among researchers from both academia and industry in networking, wireless communications, and mobile computing. The special issue includes an article investigating the issue of determining an appropriate pricing strategy for VoWLAN provisioning. Also featured are two articles on polling as a solution for supporting real-time traffic over WLANs and another on media optimization network architecture (MONA). 相似文献
106.
一、动画的表现力
动画片作为艺术的一种载体,同其他艺术形式一样担负着传达人类情感与思想的媒介作用。不仅如此,由于动画片自身所特有的表现方法,使它的表现力往往会超越其他的艺术载体,要比文字、绘画、音乐更有表现力。 相似文献
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PANGJinxing GONGYun XlONGYan ZHANGChaocan 《武汉理工大学学报(材料科学英文版)》2005,20(2):74-76
Silicon dioxide sol was synthesized by silicon tn the presence of alkali catalyst. ,SiO2 nanoparticles (size in 8- 15nm) aqueous dispersion was prepared by using dispersion and surface modification in situ. The effects of reaction time, temperature, medium pH value, dispersant and surface-modifier on their diameters, sizes distribution and dispersion stability were also studied. The experimental results show that the preparation method can effectively resolve the dispersion stability of SiO2 nanoparticles in water. 相似文献