阿达马光谱术中的数据处理方法—快速阿达马变换

本文系统的讨论了应用于阿达马光谱术中的数据处理方法——快速阿达马变换。给出了:1.阿达马矩阵的构造方法。2.阿达马光谱术中矢量方程的建立。3.置换π₁,π₂的构造。4.判别任意2ⁿ（n≥o）阶阿达马矩阵中任意元素H_μj的判别式的给出:H_μj=(-1)^{μ_n-1j_n-1+μ_n-2j_n-2+…+μ₁j₁+μ₀j₀}。5.快速阿达马变换算式的建立。6.快速阿达马算法的验证。     

CIE1976(L*a*b*)匀色空间颜色变量特性研究

CIE1976(L^*a^*b^*)颜色空间是较理想的匀色空间之一.为了使它获得更广泛合理的应用,人们继续对其进行探讨和改进.本研究利用心理物理评价实验,对该空间的诸变量特性进行了研究.     

单价银离子在 CaO-P2O5 系统玻璃中的发光特性

在弱还原气氛下制备了单价银离子(Ag⁺)掺杂的CaO-P₂O₅系统玻璃,测试了其在室温下的吸收光谱、激发光谱和发射光谱。Ag⁺-CaO-P₂O₅玻璃的吸收光谱表明两个吸收峰。高能峰位于220nm波长,由4d¹⁰→4d⁹5P¹跃迁引起,低能峰中心位于240nm波长,归因于4d¹⁰→4d⁹5s¹跃迁,该吸收与其发射特性有关。紫外波段的宽带吸收产生了可见波段强烈的荧光发射,发光峰位于440nm波长,半宽度为130nm.研究了掺质浓度与发光特性的关系,随着掺质浓度的增加(0.05～0.25mol%),发光峰向较长波段移动。在Ag₂O含量为0.5mol%时,出现了浓度猝灭现象。为了比较起见,同时还研制了Cu⁺-CaO-P₂O₅及Cu⁺-Ag⁺-CaO-P₂O₅玻璃。     

在均匀颜色空间中实现彩色图像的颜色量化

颜色量化是将原有图像中的多种颜色根据人的视觉效果归类为较少的颜色,从而用这些较少种类的颜色重新生成一幅新的图像,使量化后的图像与原图像的差别即量化误差最小.采用了将RGB非均匀颜色空间变换到L^*a^*b^*为基准的均匀颜色空间的方法,在L^*a^*b^*均匀颜色空间中对彩色图像进行颜色量化,从而解决了量化误差相对人眼不均匀的问题.首先将彩色图像的像素数据保存在单链表中,然后对链表进行扫描,并把本次扫描得到的色差最小的两个节点合并成一个新的节点.经过足够的动态运算后可得到量化处理后的图像调色板.实验结果表明,本方法具有普遍性、唯一性,可以减小量化误差,提高颜色量化的准确性.     

毫米级微型机器人操作手的研制和操作特性

采用单晶片型压电悬臂梁制作了一种双悬臂梁结构的微型夹持器,用作毫米级微型机器人的微操作手.该微夹持器整体尺寸为15mm×2mm×2mm,重量为100mg.在分析该悬臂梁操作原理的基础上,选用PbNi_1/3Nb_2/3-PbZrO₃-PbTiO₃三元系压电陶瓷准同型相界的配方作为悬臂梁压电驱动材料,这种压电陶瓷具有高压电常数 (d₃₁) 和机电耦合系数 (K_p).进一步研究了压电微夹持器的操作特性.结果表明:50V电场下,其最大张口距离可以达到40μm,最大夹持力为25.7×10^-3N.     

XPS研究吖啶橙掺杂玻璃

采用低温熔融法制备了磷酸盐基质玻璃及掺杂有机染料吖啶橙的有机/无机玻璃复合材料。用x-射线光电子能谱(XPS)测试研究了两类玻璃的结构特性。F_Is的XPS谱为双峰,说明玻璃中的F以两种键合状态存在。高能峰在687.0～687.2ev,属于P-F键；低能峰位于684.6～684.7ev,属于M-F键(M=Sn²⁺和或Pb²⁺).O_is谱给出了桥氧(BO)和非桥氧(NBO)的相对含量。有机染料吖啶橙掺杂到基质玻璃中后,F_Is谱中P-F键的相对含量增加。     

纳米半导体复合薄膜的非线性光学性质及其在激光器中的应用

采用射频磁控溅射技术制备了Ge掺二氧化硅（Ge-SiO₂）和Ge,Al共掺二氧化硅（Ge/Al-SiO₂）两种复合薄膜,并进行了热退火处理形成了纳米Ge镶嵌结构。通过紫外-可见吸收谱测量,确定了两种薄膜中纳米Ge的光学带隙,并采用皮秒激光Z-扫描技术研究了薄膜的非线性光学性质。测试结果显示,在1 064 nm激发下得到的Ge-SiO₂和Ge/Al-SiO₂薄膜的非线性吸收系数分别为-1.23×10^-7 m/V和4.35×10^-8 m/W,前者为饱和吸收,而后者为双光子吸收。把两种薄膜作为可饱和吸收体均可实现1.06 μm激光的被动调Q和被动锁模运转。与Ge-SiO₂薄膜比较,采用Ge/Al-SiO2薄膜可以获得较窄的调Q脉冲和锁模脉冲。最后,理论分析和实验比较了两种薄膜实现被动调Q和锁模的机理。     

激光光束质量的评价与应用分析

从M²因子概念出发,分析了M²因子的概念与激光本质参数之间的关系,以及几种典型光束的M²因子,研究了M²因子的局限性,比较了针对不同应用目的的常用激光束质量定义的适用范围,探讨了激光光束质量的影响因素及其控制措施.     

柔性制造系统切削稳定性在线监测技术的研究

主要讨论柔性制造系统(FMS)切削稳定性的在线监测方法,在研究FMS切削过程中振动信号变化规律的基础上^[1],提出了用μ_a=E(a)/F(a)作为FMS切削稳定性的监测参数,并进行了理论分析和试验验证.     

分离型超声波振动车削抑制颤振的实验规律研究

采用功率谱分析技术证实了由Janet Devine现发的分离型超声波振动切削对颤振的抑制作用,并由正交实验设计确定各主要参数对其抑振效果的影响程度。实验给出了切削速度v_o,刀具超声波振动振幅A及其搭配(交互作用)对抑振因子r的影响规律,这一结果与作者在文献^[1][2][3]中提出的分离型超声波振动切削消减颤振的理论相吻合。     

New approach to metamerism measurement on halftone color images

There is often a phenomenon depending on dominant tones which results in the end users dissatisfaction with halftone color reproduction. This phenomenon is known as “metamerism” and it is the subject of research for many scientists.The metamerism on halftone color images with different dominant tones (blue, red, green and yellow) was researched in this paper, at the light sources D₅₀, D₆₅ and daylight. The results of the objective and visual evaluation were presented on the basis of colorimetric measurement of the grey balance patch, by the means of MacAdam ellipsoids in three dimension CIE L^*a^*b^* system. Both the metamerism index MI and the ellipsoid volume have also been calculated.This paper confirms that the metamerism of the halftone color images can be estimated by measuring CIE L^*a^*b^* values of the grey balance patch and by calculating MacAdam ellipsoids.     

Color cathodoluminescence of BGO crystals

The color cathodoluminescence (CL) mode in scanning electron microscopy (SEM) is promising in the study of a variety of defects in single crystals pulled from the melt by the Czochralski method. The regions of homogeneous and heterogeneous capture of impurities and of point and linear defects, which affect the luminescence in the undoped Bi₄Ge₃O₁₂ (BGO) and doped BGO:V, BGO:Yb, BGO:Cr³⁺, and BGO:Fe as grown single crystals, were observed. Depending on the doped impurities and dislocation configuration, a change was found in both the intensity and wavelength of CL.     

多角度下蜡染布料的多光谱成像研究

在400~720 nm波段范围,采用基于液晶可调谐滤波器(LCTF)和CMOS相机组合的多光谱成像系统对蜡染的布料进行每隔5 nm成像。讨论了多光谱成像的基本原理和多角度下彩色图像的实现过程,并且通过计算光谱反射率展示了光谱合成颜色的基本方法。对再现后的橘色、绿色、白色、蓝色、黄色、黑色六种颜色色块进行多角度下明度值、彩度值的分析。实验结果表明,六种颜色的明度值均呈现正态分布,并且通过计算六种颜色色块的色品坐标值a~*、b~*和彩度c_(ab)~*的均方差,得出在一定的范围内,六种颜色的色品坐标a~*、b~*近似不随角度变化,其中蓝色和黑色随角度的变化更小,近似于一条直线。     

Relationship between skin color and solar elastosis in aged Asian skin: A colorimetric–pathologic correlation

Aged skin is reported to be associated with unattractive skin color changes and solar elastosis. However, comparative studies have not documented the possible correlation between the two factors. This study investigated the plausible relationship between the facial skin color of elderly Asians and solar elastosis. A total of 22 skin specimens were collected from 22 Korean patients who underwent cheek skin biopsies. Skin color was quantitatively measured using colorimetric photography techniques to produce CIE L *a *b * values; the degree of solar elastosis was quantifiably assessed using a histologic grading scale. These values were used to investigate a correlation between the CIE L *a *b * coordinates and solar elastosis grade. The solar elastosis grade increased according to patient age (r = 0.67, p = .0006). However, the extent of solar elastosis was not statistically correlated with the CIE L *a *b * values, including L *, a *, and b * (r = 0.02, p = .95; r = 0.15, p = 0.50; r = ?0.07, p = 0.76, respectively). The results showed that the solar elastosis grade increased, according to patient age, because of cumulative actinic damage. However, colorimetric skin color data did not correlate with the degree of solar elastosis. Therefore, cutaneous color changes and solar elastosis are separate, age‐related phenomena. Physicians should be aware of the possible histologic changes in actinically damaged facial skin, regardless of the skin color.     

孟塞尔颜色系统与人眼主观亮度的关系

颜色亮度测量值与人眼主观亮度感受不一致的矛盾,在孟塞尔颜色体系中也明显地表现出来。这反映在孟塞尔等明度面上各种不同颜色的主观亮度并不相等。我们通过理论分析和主观亮度匹配实验,得出了孟塞尔等明度面颜色亮度与人眼主观亮度的对应关系。     

产品色彩的配色原则与品牌形象

分析了色彩的配色原则,依据色彩的色相、明度、纯度变化关系将色彩的组合搭配分为三种形式：弱对比色彩搭配、中对比色彩搭配和强对比色彩合搭配,并探讨了在不同使用环境下,如何进行色彩的配色,进而满足人们不同的心理需求,使设计作品呈现出丰富的审美面貌,营造强烈的产品和品牌形象,最终提高企业的竞争力。     

Optimising tolerance allocation for mechanical components correlated by selective assembly

Selective assembly can enlarge the tolerances of mechanical components for easier manufacturing. However, the non-independent dimensions of correlated components make it difficult to optimise tolerance allocation for an assembly. This paper proposes a solution for this constrained optimisation problem consisting of tolerances and non-independent dimensions as design variables. The approach is to develop a simplified algorithm applying a Lagrange multiplier method to evaluate the optimal tolerances efficiently. The solution is shown to be a global optimum at the given correlation coefficients. The correlation coefficients are key elements in determining the optimal solution, which is demonstrated in the given examples. The results are helpful in designing tolerances for selective assembly.Notation A _j coefficient matrix off _j - B _i coefficient of cost function - C total manufacturing cost function - C _i manufacturing cost function forx _i - F _j thejth dimensional constraint function - f _j thejth quadratic constraint function - f quadratic constraint vector - H _j thejth Hessian matrix - J _kj element ofn×m Jacobian matrix - L Lagrangian - m number of assembly dimensions - n number of component dimensions - p number of equality dimensional constraints - T tolerance vector of component dimensions [mm] or [°] - tolerance ofx _i [mm] or [°] - tolerance ofZ _j [mm] or [°] - x component dimension vector - x midpoint vector - x _i component dimension [mm] or [°] - x _i midpoint ofx _i [mm] or [°] - Z _j assembly dimension [mm] or [°] - _j confidence coefficient forZ _j - _i confidence coefficient forx _i> - _j given design value ofZ _j [mm] or [°] - Lagrange multiplier vector - _j thejth Lagrange multiplier - * Lagrange multiplier vector at the optimum solution - correlation coefficient forx _i andx _k - _x standard deviation vector - _x ^* standard deviation vector at the optimum solution - _x ⁰ candidate point satisfying the constraintsf( _x ^* )=0 - standard deviation ofx _i      

计算机彩色图像再现系统中的颜色矫正研究

随着网络、多媒体技术的发展,计算机彩色图像再现系统中交互界面上颜色的高保真再现变得日益重要.本文结合敦煌壁画的计算机存储与管理工作,研究了从彩色扫描仪到计算机CRT显示器的颜色矫正问题,克服人为因素的影响,提出了一种新的CRT显示器色度预测方法和一种多约束因子颜色矫正还原模型.采用CIE1976(L·a·b·)匀色空间的色差函数ΔΕ进行矫正效果评价.结果表明,本文提出的颜色矫正还原模型能对扫描、显示等环节中各种因素所造成的颜色失真实现客观、定量、一次性的总体矫正,可以广泛应用到计算机彩色图像再现系统中.     

Coercive Force as a Function of Uniaxial Stresses (Part 2)

The relative anisotropy of the coercive force is investigated as a function of the tensile stress. A generalized calculated curve with coefficients averaged over all the low-carbon steels tested is constructed. A mechanism for determining the effective magnetostriction λ ₁₀₀ ^* and λ ₁₁₁ ^* from the field dependence λ(H) is proposed. The magnetoelastic sensitivity ΔH _c coefficients are determined as functions of the magnetostriction λ ₁₀₀ ^* .