Dynamic Mechanical Relaxation in the Opaque and Transparent Poly(4-Methyl-1-Pentene) Films The glass transition zone

The thermomechanical properties of opaque and transparent polymer films of a solution of poly(4-methyl-1-pentene) (PMP) in cyclohexane and carbon tetrachloride obtained by casting on teflon and glass plates were investigated. The dynamic mechanical thermal analysis was applied in a frequency range from 0.01 to 100 Hz. The curves of loss tangent vs. temperature varied depending on the sample thermal history. The first part of these curves could relate to the backbone α relaxation into the unperturbed amorphous phase while the next relaxation could result from the backbone α relaxation into amorphous phase perturbed by the presence of the crystal domains. The Arrhenius plots of the first relaxation show a stronger curvature found in each of the transparent samples indicating strong dependency on specific volume. The second one in the case of transparent films and the first one for opaque samples might be approximate to straight lines. This revised version was published online in August 2006 with corrections to the Cover Date.     

利用预失真条纹校正PMP系统投影仪畸变的研究*

依据摄像机畸变模型提出了一种投影条纹相位畸变校正方法来简化相位-高度映射关系.该方法首先通过投两套互相垂直的相移正弦条纹,以相位值代替投影仪像素坐标,将投影仪当成摄像机看待,标定出投影仪的内参量.然后根据标定出的投影仪镜头畸变参量对理想相位施加反向的畸变,在投影时反向畸变的光栅通过镜头畸变,又成为理想的光栅,从而简化了相位-高度映射关系.实验中,虽然由于测量误差的影响,校正后的投影仪径向畸变系数还是比原来小了1个数量级.     

Iterative two-step temporal phase-unwrapping applied to high sensitivity three-dimensional profilometry

Although temporal phase unwrapping method can be applied to solve some problems to measure an object with steep shapes, isolated parts or fringe undersampling in three-dimensional (3D) shape measurement, it needs to acquire and process a sequence of fringe pattern images which would take much time. Servin et al. proposed a 2-step temporal phase unwrapping algorithm, which only needs the 2 extreme phase-maps to achieve exactly the same results as standard temporal unwrapping method. But this method is only validated by computer simulation, shortage of experimental demonstration, its sensitivity coefficient G is limited, and it cannot be used when the G value is larger. We proposed an iterative two-step temporal phase-unwrapping algorithm which is an extension of Servin׳s method. First, add a fringe pattern with an intermediate sensitivity, project the fringe patterns of different sensitivity onto the tested object’s surface, and collect deformed fringe patterns with a CCD camera. Then we obtain the unwrapped phase with larger sensitivity coefficient G by cascading the sensitivity coefficients. And we derive the initial phase conditions of the 2-step temporal phase unwrapping algorithm. Finally, the experimental evaluation is conducted to prove the validity of the proposed method. The results are analyzed and compared with Servin׳s method. The experimental results show that the proposed method can achieve higher sensitivity and more accurate measurement, and it can overcome the main disadvantages encountered by Servin׳s method.     

糖类化合物PMP衍生分析进展

糖类物质的结构与组成分析在揭示其生物学功能方面发挥着重要作用,糖类化合物的衍生化分析是实现其高灵敏度定性和定量检测的有效方法。该文对一种条件温和、灵敏度高、选择性好的1-苯基-3-甲基-5-吡唑啉酮(PMP)的衍生化分析方法在糖类化合物的单糖组成、聚合度、取代度、异构体分析以及在N/O-糖链的释放和定量分析等方面的应用进展进行了综述。     

Synthesis,crystal structure,and properties of a new zinc coordination polymer [Zn(PMP)2Cl] n

A new coordination polymer [Zn(PMP)₂Cl] _n (PMP = 1-phenyl-3-methyl-5-pyrazolone) has been prepared by the reaction of zinc chloride and PMP, and characterized by elemental analysis, IR, UV, and fluorescence spectra, TG/DTA, and electrochemical analysis. Single crystal X-ray diffraction revealed that the complex is monoclinic, space group P 2(1)/n, with a = 10.850(17), b = 17.578(2), c = 10.997(18) Å, β = 104.999(3)°, V = 2025.8(5) ų, Z = 4, D_c = 1.470 mg m^?3, F(000) = 920, goodness-of-fit = 0.905, and R ₁ = 0.0441. The complex is a 1-D coordination polymer, and the coordination geometry of Zn(II) is a distorted tetrahedron.     

一种采用相位测量轮廓术的工件在线三维检测方法

提出了一种基于相移轮廓术在线检测工件三维信息的方法.利用计算机编程产生的一固定正弦光栅图通过数字投影机投射在流水线的一段区域,无需专门的相移装置,当物体在线移动穿过此区域时,使用计量光栅等距离定位发信,控制CCD采集五帧变形条纹图,并采用具有一定特征的标记实现五帧变形条纹图间的亚像素级像素匹配,提取相移变形条纹图,由Stoilov算法计算,得到工件表面截断相位,展开后可得到物体表面三维信息.实验验证了其可行性.