The behavior of best -approximations as . A counterexample of convergence

In the space of summable sequences we give an example of a one-dimensional affine subspace C such that the best L_p-approximations of 0 from C fail to converge as p↓1. We thus give an answer to this problem of convergence in infinite measure spaces.     

A new exclusion test for finding the global minimum

Exclusion algorithms have been used recently to find all solutions of a system of nonlinear equations or to find the global minimum of a function over a compact domain. These algorithms are based on a minimization condition that can be applied to each cell in the domain. In this paper, we consider Lipschitz functions of order α and give a new minimization condition for the exclusion algorithm. Furthermore, convergence and complexity results are presented for such algorithm.     

复杂显示中诱导域彩度对目标色貌的影响

用双目不对称匹配法测试了在复杂显示中目标色貌与其周围诱导域彩度的关系。结果表明：当保持目标与周围的色调相同且亮度不变,只改变诱导域的彩度时,色诱导引起的目标色觉位移的大小随诱导域彩度的增加而增加,色觉位移的方向大多数不随诱导域彩度改变,基本指向该色调彩度降低的方向。     

全彩色LED显示屏的色度计算

全彩色ＬＥＤ显示屏可以用来显示电视画面。目前没有专门用于ＬＥＤ彩色大屏幕的图像源及其标准,所以都是将送给ＣＲＴ显像管的图形信号源送到ＬＥＤ彩色大屏幕进行显示。针对把送给ＣＲＴ的信号送到ＬＥＤ屏进行显示会引起彩色失真这种情况,本文给出ＬＥＤ大屏幕系统的色度公式,为准确控制ＬＥＤ管的发光亮度提供理论依据,并给出产例。     

全彩LED大屏幕视频图像信号的校正

全彩ＬＥＤ大民间葜可以用来显示电视画面。由于ＣＲＴ发光特性的非线笥,在图像信号源处引入一种称为γ校正的相反预失真来补偿ＣＲＴ的这种非线性。但由于全彩ＬＥＤ大屏幕系统的发光特性与ＣＲＴ的发光特性不同,它的发光亮度与其控制量成线性关系,因此在显示电视画面时会引适合ＬＥＤ屏的显示。此外,还考虑到人的视觉的明亮度与物理亮度的关系。本文给出了一种对ＬＥＤ大屏幕信号进行校正的方法,即γ校正,实验结果表明效果极     

新显色剂N-对甲苯基-N′-(氨基对苯磺酸钠)硫脲的合成及与金(Ⅲ)显色反应的研究和应用

介绍了新试剂N-对甲苯基-N'-(氨基对苯磺酸钠)硫脲(PMPT)的合成。经过红外、紫外、核磁共振和元素分析等方法测试, 确定了其组成和结构。并研究了试剂与金(Ⅲ)的显色反应, 建立了光度法测定微量金(Ⅲ)的新方法。 在pH3.2～5.8的HAc～NaAc缓冲体系中, 该试剂和金(Ⅲ)形成一种稳定的组成比为1∶2的水溶性配合物,配合物的最大吸收峰位于312.6nm处,表观摩尔吸光系数为2.54×10     

The Effective Gluon Propagator in the Global Color Symmetry Model

It is shown that the effective gluon propagator in the global color symmetry model can be calculated in the instanton dilute liquid approximation. The calculated effective gluon propagator is consistent with the general command on the qualitative features of the gluon propagator, i.e., (i) the gluon propagator is significantly enhanced at small space-like k², and (ii) for k² > 1.5 GeV² the perturbative results are quantitatively reliable.     

彩色多通道光栅投影轮廓术

研究了一种双通道光学相位测量轮廓术。利用彩色空间中红色与蓝色互相独立、互不干扰的特性,将两个相位相反的线性周期变化的光栅分别放在红以与蓝色通道,形成彩色双通道投影光栅。用彩色ＣＣＤ获取图像,并和图像采集卡将图像送入计算机。从彩色图像的红色与蓝色通道可分别获得两个互相反相位的线性周期光栅的调制图。在一次采样中即可获得两个通道的测量结果,因而特别适用于动态测量。     

Preparation of (KBr‐KCl)(OH−):(F2+)H color center laser crystal series and their spectral characteristics

In order to adjust and broaden the absorption spectrum and emission spectrum of the (F₂⁺)H type color center so as to match up to the pumping and to fit in with the demand of application, a (KBr‐KCl)(OH⁻):(F₂⁺)H color center laser crystal series was prepared by the process of single crystal growth, additive coloration, anneal, and light aggregation at 290 K and 77 K. The spectral characteristics of (KBr‐KCl)(OH⁻) crystals are investigated. It is found that the absorption and emission band of the (F₂⁺)H color centers in KBr‐KCl complex host crystals has a considerable adjustment and extensions compared to the color centers in single KBr or KCl crystal. (© 2003 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)     

双层有机电致发光器件中的激基复合物发射及特性

以两种常用的芳香二胺TPD和NPB为空穴传输材料(HTM)和BBOT为电子传输材料组成双层器件,获得了相对于组成材料的荧光光谱红移和宽化的电致发光.用光致发光表征了这种发射来自激基复合物,并用器件的能级图说明激基复合物的类型为BBOT的激发态BBOT^*与基态的HTM相互作用的复合物.比较TPD和NPB的分子结构和能级表明,分子具有有利的构型和取向比合适的能级更容易形成激基复合物.