LIN Junshan
,
LI Pengxing
,
WU Renjie Shanghai Jiao Tong University
,
Shanghai
,
China postdoctoral
,
Institute of Composite Materials
,
Shanghai Jiaotong University
,
Shanghai 200030
,
China
金属学报(英文版)
The differential scanning calorimetric(DSC) and transmission electron microanalysis (TEM) techniques were used to study the kinetic process of precipitation in matrix of cast SiC_p/2024 composites.The results showed that precipitation reactions of GP zone and intermediate phase S'(Al_2CuMg)in the composites were accelerated compared with SiC-free material,the peak temperatures of both reactions were decreased.The reaction enthalpies of both the GP zone and intermediate phase S' formation in the matrix were substantially decreased after the addition of SiC.TEM analysis found that the alloying element Mg segregated at the SiC/Al interfaces,and was depleted in the matrix near the interface.The precipitation-free zones(PFZ) and precipitation-sparse zones(PSZ) formed near the interfaces,as a results,the volume fraction of precipitates in matrix was reduced.
关键词:
SiC_p/2024 composite
,
null
,
null
Author X.A. Zhang1)
,
H.Q. Xia1)
,
Z.T. Wu1)
,
Y.F. Han1)
,
R. Shi2) and G.X. Hu2) \= 1) Mechanical Properties Laboratory
,
Beijing Institute of Aeronautical Materials
,
Beijing 100095
,
China2) The State Education Commission Open Research Laboratory for High Temperature
金属学报(英文版)
Materials and Testing, Shanghai Jiao Tong University, Shanghai 200030, ChinaManuscript received 18 October 1998 The threestage creep behavior of DD3 single crystal superalloy had been studied. The results show that the creeprupture properties of DD3 single crystal satisfy the requirements for high performance turbine blade application. The influence of crystal orientation on the creeprupture property of DD3 single crystal was tested and discussed. An engineering criterion to evaluate the regimes of secondary and tertiary creep is proposed, and this method gives a reasonable result for practical applications. The fractography and TEM micrography of the tested specimens had been studied, and it is determined that the glidecontrolled creep is the basic creep mechanism of DD3 single crystal at intermediate temperature, but the thermally activated processes become dominant at higher temperature.
关键词:
threestage creep curve
,
null
,
null
,
null
李铂
,
周建江
,
夏伟杰
,
吴连慧
液晶与显示
doi:10.3788/YJYXS20142904.0605
直线是机载座舱显示画面中最基本的图元,其显示质量对于整个画面的显示效果影响较大,尤其是小角度下直线显示的“麻花”现象一直是影响显示效果的关键问题之一.为了提高小角度下直线的显示效果,本文提出了一种基于Wu算法的亮度渐变改进算法.该算法通过渐进地展现直线从轴方向上的亮度变化过程,减少亮度畸变,有效地改进了显示效果.通过Matlab仿真和FPGA实现,验证了该算法反走样后的小角度直线显示效果明显优于其他算法,而且结合中点画线法后,绘制时间与Wu算法相当.同时该算法还可改善大角度直线和圆弧的显示效果,消除了大角度直线的边缘锯齿,解决了圆弧在小角度部分的虚化问题.因此本文算法可用于对实时性和显示效果要求高的机载座舱显示系统,以缓解飞行员的视觉疲劳.
关键词:
座舱显示
,
反走样
,
改进Wu算法
,
小角度
,
FPGA实现
吴连慧
,
周建江
,
夏伟杰
,
陈雅雯
液晶与显示
doi:10.3788/YJYXS20153001.0163
对于光栅化的三角形,其边缘存在明显的锯齿现象,因此需要进行反走样处理.基于Wu直线反走样算法的思想,考虑了水平直线外侧直接添加插值点的算法和三角形三边外侧反走样的算法.综合两者的优点,在绘制光栅化的三角形的同时,边缘叠加Wu反走样直线,并考虑背景像素灰度值的作用.结果表明,改进的三角形光栅化的边缘反走样算法有效提高了三角形光栅化后边缘的显示效果,该算法计算量小,便于FPGA实现,可用于对图形显示质量要求很高的机载显示系统.
关键词:
反走样
,
Wu算法
,
光栅化
,
FPGA
胡跃鑫
,
冯玉林
,
姜伟
应用化学
doi:10.3724/SP.J.1095.2011.00521
采用不同尺寸的碳酸钙粒子增韧高密度聚乙烯,研究了不同温度下共混体系的临界粒子间距与碳酸钙粒子尺寸和含量之间的关系,确定了温度是Wu氏增韧理论临界粒子间判据适用性的重要影响因素.结果表明,在17℃下,临界粒子间距与碳酸钙粒子的尺寸和含量无关,该条件下Wu氏增韧理论临界粒子间距判据是适用的;而随着温度的升高,发现临界粒子间距依赖于碳酸钙粒子的尺寸,表明高温条件下,Wu氏增韧理论临界粒子间距判据不再适用.
关键词:
聚合物增韧
,
粒子间距
,
脆韧转变
新型炭材料
The 2011 Annual World Conference on Carbon (Carbon 2011) was held in Shanghai, China, during 24-29 July, 2011. This conference was hosted jointly by East China University of Science and Technology, University of Shanghai for Science and Technology, and Institute of Coal Chemistry Chinese Academy of Sciences. About 800 attendees from 42 countries/regions participated in this conference, and 797 papers were accepted for presentation, including 5 plenary lectures, 42 keynote lectures, 280 oral presentations, and 470 posters, involving 10 topics: graphene; nanocarbon, carbon for energy storage and conversion, porous carbon and adsorption, carbon fiber and composites, precursor/carbonization and graphitization, computation and modeling, bio-carbon and safety, novel experimental techniques and characterization, bulk carbon and industrial applications. Research and development of nanocarbons are quite active and in particular, graphene received tremendous interest. Rapid progress has also been made on the electrochemical properties, energy conversion and energy storage applications of carbon materials.
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