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
Chinese Physics Letters
Er3+-doped and Yb3+/Er3+ co-doped Gd3Sc2Ga3O12 (abbreviated as Er:GSGG and Yb,Er:GSGG, respectively) laser crystals are investigated by using a combination of spectroscopic measurements and thermal characterizations. An absorption peak of Yb, Er: GSGG crystal shifts to 970 nm and its absorption band broadens obviously, which makes the crystal suitable for pumping by a 970 nm laser diode (LD). This crystal also exhibits a shorter lifetime of a lower laser level, a larger emission cross section and higher thermal conductivity than those of Er: GSGG. All these factors suggest that Yb3+/Er3+ co-doping has a positive effect on improving the spectroscopic and thermal performances in GSGG based laser crystals, and imply that double-doped Yb, Er: GSGG crystal is a potential candidate as an excellent LD pumped 2.79 mu m laser material.
关键词:
mu-m;energy-transfer;gsgg laser;er3+;yag;irradiation;absorption;spectra;ysgg;yb3+
Zeitschrift Fur Metallkunde
A systematic reexamination of the Er - Co system was carried out by differential thermal analysis, optical microscopy, X-ray diffraction and EPMA techniques. A revised Er - Co binary phase diagram is proposed. This binary system consists of four peritectic reactions, three reactions of congruent melting and a eutectoidal reaction. The four peritectic reactions result in the formation of Er3Co, ErCo2, Er2Co7 and ErCo5, respectively. The three congruent reactions involve the formation of almost-equal-to Er16Co9, ErCo3 and Er2Co17. The eutectoidal reaction involves the decomposition of ErCo5 into Er2Co7 and Er2Co17. There are also four eutectic reactions in this system. The solid solubility of Er in Co is extremely small.
关键词:
intermetallic compounds
赵中魁
,
周铁涛
,
刘培英
,
陈昌麒
稀有金属材料与工程
采用TEM对5.6%Zn,1.9%Mg,1.6%Cu,1.0%Li,0.3%Er(质量分数)合金中的Er相进行研究,发现Er在合金中主要以AEr形式存在,Al3Er在合金中的形状为块状、点状、片状或蠕虫状,部分Al3Er与铝合金基体共格.细小的Al3Er可作为η相异质形核的核心.Er在合金的晶界有很大的偏析,而且晶界处Al3Er的存在,使该处晶界析出物不连续.
关键词:
Er
,
AEr
,
晶界
Solid State Communications
Er-doped Si-rich SiO2 (SRSO:Er) films have been deposited on n(+)-Si substrates by the magnetron sputtering technique, and both photoluminescence (PL) and electroluminescence (EL) at 1.54 mum have been observed from the films at room temperature. Dependence of pi, and EL intensities on the excess-Si content and annealing temperature has been studied. It is found that proper Si content and annealing temperature can evidently enhance EL intensity. An SRSO:Er film with 20% excess Si (area ratio of the Si target to the whole target) had more intense EL than a SiO2:Er film without excess Si, both annealed at 800 degreesC, by a factor of 5. This fact clearly demonstrates that energy coupling between Si nanometer particles and Er3+ ions also exists in the EL process as well as in the PL process. Experimental results also indicate that crystallization is not a prerequisite for NSPs enhancing luminescence in SRSO:Er films. The PL and EL spectra of the SRSO:Er films have much broader full widths at half maximum (FWHM, similar to 60 nm) than those of the other Er-doped materials reported. This wide FWHM can perhaps be used in wavelength division multiplexing in optical communication in future. (C) 2001 Elsevier Science Ltd. All rights reserved.
关键词:
thin films;nanostructures;recombination and trapping;luminescence;molecular-beam epitaxy;oxygen-doped silicon;erbium;nanocrystals;light;oxide
