基于自由镜面反射位姿评估的条纹反射摄影测量

在条纹反射摄影测量中,由于产生条纹图形的液晶显示器不直接出现在摄像机的视场范围内,摄像机与液晶显示器之间的位姿标定是条纹反射摄影测量的主要难点。为了简化标定过程,提出了采用平面镜直接对液晶显示器上的条纹反射3次并利用固定摄像机接收反射条纹,通过对摄像机与条纹虚像之间的3次位姿评估,完成摄像机与液晶显示器的位姿标定的方法。在镜面面形测量中,利用两者之间的位姿关系可以将待测点的反射光线和入射光线统一在摄像机坐标系下,完成光线的三角交会,实现镜面面形测量。数值模拟和实验结果表明,此方法简单易行,且精度较高。     

单目多视点立体图像提取及应用

设计并实现了一种基于广角相机和平面镜的单目多视点立体图像摄像系统,给出了硬件装置的设计指标和优化方法;同时,在研究了硬件系统的标定方法基础上,实现了其在三维测距方面的应用。多枚平面镜构成的对称斗型腔体被放置在广角相机前面,物体光线经过不同平面镜反射后,投影到相机图像平面的不同区域,在相机投影平面上生成物体多个影像,形成单目多视点投影图像。该类图像等价于视点不同的多幅图像,可以使用多视点立体视觉算法实现三维测量。     

低光泽度印刷色谱色貌数据组的建立与评价

色貌预测是现代颜色科学领域的基本理论和技术。为了评价低光泽度彩色印刷色谱的色貌,以丽印胶版纸印制的彩色印刷色谱为研究对象,根据颜色科学和心理物理学相关实验,建立其色貌参数样本数据组。采用相对系数R2和差异系数CV等数理统计方法,评价这种印刷色谱中Y-M内页在三种不同的照明光源下色貌的视觉评估结果。实验数据分析表明,在D65、A和TL84三种光源中,人眼在A光源下对颜色的识别能力明显不同于D65和TL84光源;同样在这三种光源中人眼对明度和色调的评估准确度最高,彩度最差。     

基于拉格朗日跟踪法的波纹流道流体特性研究

采用正交实验方法考察了具有不同结构参数的三维周期波纹流道中的流体性能,并采用Webb评价方法对其进行性能评价。比较了不同波纹宽度的波纹流道的阻力因子e_f、传热因子e_Nu和能效因子η的值,结果表明三者都随Re的增大而增大,波纹宽度最小时能效因子η最大。流体在波纹流道中垂直于主流方向的横截面上产生二次流,随着Re增大,二次流增强,阻力增大,温度边界层减薄,温度等值线分布变得不均匀,传热增强。采用拉格朗日粒子跟踪技术分析了不同Re下,流体粒子在波纹流道内的运动轨迹,绘制了不同周期出口流体粒子的庞加莱截面图,结果表明流体粒子在波纹流道中被反复拉伸和折叠,增加了流体粒子的接触面积,提高混合效率,强化了传热。     

The magnet design for the HLS storage ring upgrade project

In order to improve the performance of the Hefei Light Source (HLS), in particular to get higher brilliance synchrotron radiation and increase the number of straight section insertion devices, an upgrade project called HLSII will be launched soon. The storage ring lattice, which has a double bend achromatic structure with four periods, comprises eight dipoles, 32 quadrupoles and 32 combined function sextupoles. The design and analysis of the magnets are shown in this paper, along with the optimization of the multipurpose combined function magnet, which consists of three magnets: skew quadrupole, horizontal dipole and vertical dipole, with the main sextupole magnet. This type of magnet is the first one that has been designed and used in China. The mechanical design and fabrication procedures for the magnets are also presented.     

A series of new hybrid compounds constructed from Dawson-type phosphomolybdates and metal–organic coordination complexes

In this study, a series of compounds based on Dawson-type phosphomolybdates, H₃(C₆NO₂H₆)₂[K(H₂O)₃(C₆NO₂H₅)₃][P₂Mo₁₈O₆₂] ? 5.5H₂O (1), (C₆NO₂H₆)₆[Ln(H₂O)₇(C₆NO₂H₅)₂]₂[P₂Mo₁₈O₆₂]₂·13.5H₂O (Ln = Ce (2), La (3)) have been synthesized and characterized by elemental analysis, IR and UV-Vis spectroscopy methods, TG analysis, and single-crystal X-ray diffraction. Compound 1 consists of [P₂Mo₁₈O₆₂]^6? building units joined by potassium-pyridine-3-carboxylic acid complexes, resulting in a wavelike polyoxometalate (POM) chain, which further interacts with each other via intermolecular interactions to form a 3-D supramolecular channel framework containing guest water molecules. Compounds 2 and 3 possess a 3-D supramolecular framework with 1-D tunnel constructed from [P₂Mo₁₈O₆₂]^6? and mononuclear lanthanide coordination complex fragments. To the best of our knowledge, 1 not only represents the first example of 1-D hybrid assembly based on Dawson-type phosphomolybdate, but also the first hybrid compound constructed from Dawson-type POMs and alkali–metal coordination complex fragments.     

Isentropic compressibilities of the mixture chlorobenzene + n-hexane + (n-heptane or n-octane) at 298.15 K

In this work, the applicability of the free length and the collision factor theories (FLT and CFT, respectively) to predict multicomponent changes of isentropic compressibilities is analysed and compared. To this end, appropiate expansions for ternary mixtures were derived from the original works, and then applied to a mixture containing unlike compounds in terms of functional molecular groups. Experimental data of excess molar volumes from open literature and new experimental isentropic compressibilities of the mixture chlorobenzene?+?n-hexane?+?(n-heptane or n-octane) were used to compute the parameters. A good accuracy was obtained when ternary prediction is attempted in this partially soluble mixture at different temperatures by the collision factor theory. These results show the versatility of this model for estimation in complex multicomponent mixtures with phases splitting.     

Dual role of price and myopia in a marketing channel

In this paper we study a dynamic two-player channel where the manufacturer controls the wholesale price and the investment in quality and the retailer chooses the retail price. We consider that the retail price affects both the demand and the perceived quality of the brand and that its variations contribute to the building of an internal reference price. One of the model’s distinctive features is that it accounts for the two meanings of price, i.e., its classical objective measure of the cost of acquiring a particular quantity of the product, and its subjective roles as an assessment of the quality of the product and an evaluation of gains or losses (deal vs. sacrifice) resulting from buying a “cheap” or an “expensive” product. This dual computation is done with respect to the internal reference price.     

The Calibration Problem in Statistics and Its Application to Chemistry

Abstract

Most linear regression problems involving prediction or estimation require determining the Y value corresponding to a given X. The calibration problem (or inverse estimation or discrimination) is the inverse of the above situation in that we have a given value of Y and we want to determine X. This paper will document the various statistical approaches to this problem and do a numerical example using the classical estimator.