G.M. Cao
,
C.G. Li
,
Z.Y. Liu
,
D. Wu
,
G.D. Wang
,
X.H. Liu
金属学报(英文版)
Coupled turbulent flow, temperature fields of the twin-roll casting strip process were simulated by three-dimensional finite element method. Based on the heat balance calculation and using inverse methods between the simulations and real experiments, the relational models among casting speed, location, and coefficient of heat transfer between molten metal and rolls in different regions are given. In the simulation, the calculated surface temperatures are in good agreement with the measured values. An on-line model of kiss point is derived by simulations and the geometry of molten
pool, corresponding control strategy is also proposed.
关键词:
Twin-roll strip casting
,
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
Philosophical Magazine
The error of Equation (15b) in my article [Z.D. Zhang, Phil. Mag. 87 (2007) p.5309] in the application of the Jordan-Wigner transformation does not affect the validity of the putative exact solution, since the solution is not derived directly from that equation. Other objections of Perk's comment [J.H.H. Perk, Phil. Mag. 89 (2009) p.761] are the same as those in Wu et al.'s comments [F.Y. Wu et al., Phil. Mag. 88 (2008) p.3093; p.3103], which do not stand on solid ground and which I have sought to refute in my previous response [Z.D. Zhang, Phil. Mag. 88 (2008) p.3097]. The conjectured solution can be utilized to understand critical phenomena in various systems, whereas the conjectures are open to rigorous proof.
关键词:
3D Ising model;exact solution;conjecture;critical phenomena;ferromagnetism;magnetic phase transition;model;analyticity
Physics and Chemistry of Liquids
In earlier work, Ma [S.K. MA, Phys. Rev. Lett., 29, 1311 (1972)] has studied the critical exponents and for charged and neutral Bose gases. Here we use the result of Ma, valid for general dimensionality d but only to O(m-1), where m is the number of components of the Bose field, to write a relation between (d) and (d) to O(m-1). This then motivates, but now for the Ising model, a relationship between the critical exponents and , via the dimensionality d. We finally demonstrate a connection between the two renormalisation group eigenvalues yt and yh, via the critical exponent with a dimensional dependence.
关键词:
critical exponents;Ising model;dimensionality
赵国华
,
齐砚勇
,
潘玉峰
硅酸盐通报
对YNLL水泥厂2500 t/d生产线进行热工标定并分析,系统烧成热耗为3889 kJ/kg.cl,高于全国平均水平.高温风机拉风偏大,一级筒出口温度为370℃,偏高.篦式冷却机效果欠佳,AQC抽风量偏高,直接影响了熟料质量和余热发电量,热回收效率偏低.经过改进和优化,熟料产能提高为2600 t/d.该生产线系统还有比较大的潜力,熟料产量还有可能进一步提高,热耗及电耗均可能明显下降.
关键词:
热工标定
,
新型干法水泥
,
篦冷机
曹华夏
,
毕金栋
,
李昌勇
硅酸盐通报
对LNZL水泥厂2500 t/d生产线进行热工标定并分析,该厂熟料产量超过设计产量28.96％,达到3224.1t/d.系统烧成热耗为3302.6kJ/kg熟料,低于全国平均水平,一级筒出口温度为334℃,稍有些偏高;系统的分离效率为91.49％,出预热器飞灰量偏高,还有明显的改善空间.篦式冷却机效果欠佳,直接影响了熟料质量和余热发电量,热回收效率也偏低.该生产线系统还有比较大的潜力,如经过改进和优化,熟料产能还有可能进一步提高,热耗及电耗均可明显下降.
关键词:
热工检测
,
水泥生产线
,
运行情况
Physical Review B
In the investigation of the optical and magnetic properties of the semiconductors containing transition-metal ions, the one-electron orbital cannot be treated with a pure d orbital because of a strong covalence. This paper presents the energy matrix of the d*(8) and d*(2) (d* means a modified d function) system, in which the covalence is described by two covalent factors. The differences between the matrix diagonal elements of the t(2)(m)e(n) term of the d*(8) system and the t(2)(6-m)e(4-n) term of the d*(2) system vary with m and n. The d(N) electron system can be explained with the d(10-N) hole system because the difference between the energy matrix of the d(N) and d(10-N) systems has a fixed value. However, this kind of simple relation does not exist for the d*(N) and d*(10-N) systems when the covalence is considered. A numerical calculation shows that the variation of the energy levels with the covalence for Ni2+ in the d*(8) electron system is larger than that in the d*(2) hole system. The calculated energy levels obtained from the d*(8) matrix are in good agreement with the experimental data of the Ni2+ ion for ZnS:Ni and ZnSe:Ni. This suggests that the d*(8) electron system instead of the d*(2) hole system should be used in the investigation of optical and magnetic properties of semiconductor containing Ni2+ ions.
关键词:
zns-ni;absorption;vanadium;impurities;spectra;ions
Materials Chemistry and Physics
In this study, the phytic acid conversion coating, a new environmentally friendly chemical protective coating for magnesium alloys, was prepared. The influences of phytic acid concentration on the formation process, microstructure, chemical state and corrosion resistance of the conversion coatings on AZ91 D magnesium alloy were investigated by means of weight gain measurement, field-emission scanning electron microscopy (FESEM), Fourier transform infrared (FTIR) spectroscopy, potentiodynamic polarization method and electrochemical impedance spectroscopy (EIS), respectively. And the depth profile of all elements in the optimal conversion coatings was analyzed by auger electron spectroscopy (AES). The results show that the growth, microstructure, chemical state and corrosion resistance of the conversion coatings are all obviously affected by the phytic acid concentration. The concentration of 5gl(-1) corresponds to the maximum weight gain. The main elements of the coating are Mg, Al, O, P, and C, which are distributed gradually in depth. The functional groups of conversion coatings formed in higher concentration phytic acid solution are closer to the constituent of phytic acid than those formed in lower concentration phytic acid solution. The coatings formed in 1-5 gl(-1) are integrated and uniform. However, those formed in 20-50 gl(-1) have some micro-cracks on the (x phase. The coating formed in 5 gl(-1) has the best corrosion resistance, whose open circuit current density decreases about six orders than that of the untreated sample, although the coatings deposited in 1-20 gl(-1) can all improve the corrosion resistance of AZ91 D. Crown Copyright (C) 2008 Published by Elsevier B.V. All rights reserved.
关键词:
concentration;magnesium alloys;phytic acid;conversion coatings;corrosion-resistance;chromatography;behavior;copper;mg
