酚酞型聚芳醚砜共聚物的合成和结构及热性能研究

<正> 聚芳醚砜是一类具有重要发展前景的高分子材料.合成带有酞侧基的僵硬链高分子,可提高其玻璃化转变温度,是获得耐热高分子的一种途径.最近,刘克静等从改进合成技术,使酚酞型聚芳醚砜的生产有了现实性.并且发现在改进的聚合条件下,酚酞表现出类似“自催化”的作用,能使聚合反应速度明显加快.其反应机理正在研究中. 本文为进一步验证酚酞的特殊反应性,了解因酚酞介入的共聚反应行为及其对聚合物结构和性能的影响,提高普通聚芳醚砜的使用温度或改善其流动性,设计合成了酚酞与几种不同结构双酚的共聚物.并对其结构和性能关系进行了探讨.本文报道了对共聚物     

置换络合滴定法测定硅钡合金中钡

采用置换络合滴定法,在pH10缓冲溶液中,以Cu-EDRA和PAN构成的指示剂体系测定钡,终点颜色鲜艳敏锐,方法精密度高,操作简单快速,与硫酸钡重量法对照.结果满意.     

Three-dimensional dynamic Green’s functions in transversely isotropic bi-materials

By virtue of a complete representation using two displacement potentials, an analytical derivation of the elastodynamic Green’s functions for a linear elastic transversely isotropic bi-material full-space is presented. Three-dimensional point-load Green’s functions for stresses and displacements are given in complex-plane line-integral representations. The formulation includes a complete set of transformed stress–potential and displacement–potential relations, within the framework of Fourier expansions and Hankel integral transforms, that is useful in a variety of elastodynamic as well as elastostatic problems. For numerical computation of the integrals, a robust and effective methodology is laid out which gives the necessary account of the presence of singularities including branch points and pole on the path of integration. As illustrations, the present Green’s functions are analytically degenerated to the special cases such as half-space, surface and full-space Green’s functions. Some typical numerical examples are also given to show the general features of the bi-material Green’s functions.     

用电容传感器测金属杨氏模量的不确定度分析

本文以变极距电容传感器测量金属杨氏模量为例 ,从工作原理、实验方法、测量结果等方面对测量的不确度进行了分析探讨     

Opto-electronic displacement gauge based on speckle interferometer

Modern technology demands precise distance measurements. People have used many phenomena for this purpose but there is always a need for less expensive and more reliable devices. In this paper we present a simple opto-electronic distance measurement gauge based on the phenomenon of speckling phenomenon. In the proposed setup we substitute diffraction gratings, which are commonly used in displacement gauges, with a rough surface. When illuminated by a coherent and monochromatic beam the surface scatters light to form a speckle field, whose intensity variations are read by one or more detectors. These changes are related to displacement of the rough surface and, therefore, can be utilized for displacement measurements. The presented setup has some important advantages over the grating approach: lower mechanical tolerances on parts and being based directly on the wavelength of light instead of the period of a grating. Also, it is less expensive, so can offer a viable solution for medium accuracy distance measurements.     

低温环境中位移测量的实现

针对EAST装置极向场中心螺管线圈测试实验中线圈位移量的测量,对低温环境中的位移测量方法进行了探讨,并提出了一种有效消除温度影响的位移测量方法:恒流源输入式位移测量。     

三维电子散斑干涉载频调制及其在柴油机上的应用

将电子散斑干涉场的三维载波调制技术应用到三维物体变形测量中.用水平方向、竖直方向及垂直试件表面的三路相干光分别照明物体,在水平和竖直方向通过控制反射镜的微小偏转引入载波,实现位移场干涉条纹的调制;利用物体的微小偏转实现离面位移场干涉条纹的调制;结合傅里叶变换法,分别解调出变形场的位相,从而实现了物体三维变形场的精确测量.将该技术应用到柴油机油泵的三维位移测量上,成功测量了油泵的三维位移场.     

一种新型液体浓度检测系统研究

以光电位置敏感器件作为接收器件,提出了一种利用双折射光透方法的液体浓度检测系统.该系统主要由半导体激光器、光学系统、位置敏感器件信号调理电路、单片机系统、A/D转换电路和显示电路组成.该检测方法的准确性进行了理论分析和实验仿真,并分析了影响检测结果的主要因素.实验表明,温度漂移和光源强度对本系统的影响非常小.     

Analysis of 2-D motion tracking in ultrasound with dual transducers

We study displacement and strain measurement error of dual transducers (two linear arrays, aligned orthogonally and coplanar). Displacements along the beam of each transducer are used to obtain measurements in two-dimensions. Simulations (5 MHz) and experiments (10 MHz) are compared to measurements with a single linear array, with and without angular compounding. Translation simulations demonstrate factors of 1.07 larger and 8.0 smaller biases in the axial and lateral directions respectively, for dual transducers compared to angular compounding. As the angle between dual transducers decreases from 90° to 40°, for 1% compression simulations, the lateral RMS error ranges from 2.1 to 3.9 μm compared to 9 μm with angular compounding. Simulation of dual transducer misalignment of 1 mm and 2° result in errors of less than 9 μm. Experiments demonstrate factors of 3.0 and 5.2 lower biases for dual transducers in the axial and lateral directions respectively compared to angular compounding.