微波消解ICP—AES法测定聚丙烯材料中铅、镉、铬和汞

采用微波消解技术溶样,ICP-AES法测定聚丙烯（PP）材料中的铅、镉、铬和泵。通过对消解试剂和微波温度程序的研究,建立塑料样品的微波消解方法。该方法相对标准偏差（n=7）均小于2.0%。与标准物质对比分析结果表明,方法具有良好的准确度,适于PP材料中铅、镉、铬和汞的测定。     

塑料排水板强化软基固结工程效果分析

针对某软土地基工程，进行了沉降量、设排水板与不设排水板时的固结度、固结速率的对比分析。分析表明在一定厚度范围内粘性土土层越厚，固结效果越好，在土层较薄的情况下固结的效果不是很明显。     

Increasing ionic conductivity and mechanical strength of a plastic electrolyte by inclusion of a polymer

In this contribution we present a soft matter solid electrolyte which was obtained by inclusion of a polymer (polyacrylonitrile, PAN) in LiClO₄/LiTFSI-succinonitrile (SN), a semi-solid organic plastic electrolyte. Addition of the polymer resulted in considerable enhancement in ionic conductivity as well as mechanical strength of LiX-SN (X = ClO₄, TFSI) plastic electrolyte. Ionic conductivity of 92.5%-[1 M LiClO₄-SN]:7.5%-PAN (PAN amount as per SN weight) composite at 25 °C recorded a remarkably high value of 7 × 10⁻³ Ω⁻¹ cm⁻¹, higher by few tens of order in magnitude compared to 1 M LiClO₄-SN. Composite conductivity at sub-ambient temperature is also quite high. At −20 °C, the ionic conductivity of (100 − x)%-[1 M LiClO₄-SN]:x%-PAN composites are in the range 3 × 10⁻⁵-4.5 × 10⁻⁴ Ω⁻¹ cm⁻¹, approximately one to two orders of magnitude higher with respect to 1 M LiClO₄-SN electrolyte conductivity. Addition of PAN resulted in an increase of the Young's modulus (Y) from Y → 0 for LiClO₄-SN to a maximum of 0.4 MPa for the composites. Microstructural studies based on X-ray diffraction, differential scanning calorimetry and Fourier transform infrared spectroscopy suggest that enhancement in composite ionic conductivity is a combined effect of decrease in crystallinity and enhanced trans conformer concentration.     

基于机器视觉的塑胶制品表面缺陷自动检测技术

详细阐述了机器视觉的照明系统、CCD摄像机、图像增强、图像分割、图像识别等关键技术的发展现状,并介绍了机器视觉技术在塑料电子元件、带材、PVC建材、薄膜、皮革、塑料瓶子等塑胶制品表面缺陷自动检测中的应用现状.     

塑料杯成型工艺及注塑模设计

本文对水杯的技术要求和工艺结构进行了分析,确定了工艺方案及模具形式。而且对水杯进行了相关数据的分忻与计算,根据分析结果选注塑机和注塑工艺,从而确定聚丙烯水杯设计思路及方案,最后在设计过程中运用Pro／E、Auto CAD软件进行注塑模结构设计与计算并绘制出模具总装图以及部分非标准图形。     

Yield in Adhesive Joints and Design of Zones with Constant Elastic Shear Stresses

Yield in adhesive joints has been investigated by several scientists among whom L. J. Hart-Smith¹ especially is to be mentioned.

In the following, a method is demonstrated which is based on a simple elastic-plastic model. It shows the distribution of stresses in the adhesive and gives a total picture of the development of the length of the yield zones and their strain as a function of load.

Methods are given for the design of adhesive joints with constant elastic shear stresses at their ends or throughout their whole length. These stresses are obtained by varying the thickness of the adherends, the adhesive, or a combination of both. The constant elastic shear stress zones can be designed to take into consideration all known factors as temperature and hardening stresses, moments, etc. The characteristic yield properties as well as internal stresses after yield and unloading are determined together with the modified stress distribution for a new load.     

弹性金属塑料瓦推力轴承的滑移问题研究

本文对流体力学的经典雷诺方程中固液界面无滑移假设对于弹性金属塑料瓦的适用性提出疑问，从理论上论证在一些表面能低的聚合物表面存在滑移的可能性，并进行对比实验，实验证明在聚四氟乙烯与润滑油的界面上存在滑移现象，发现滑移是在剪切速率和油膜厚度达到一定值才出现的，滑移速度随着转速的提高和膜厚的减小而增大。在分析以聚四氟乙烯为表面的弹性金属塑料轴瓦的润滑机理时，应当对雷诺方程进行修正，计入滑移因素的影响。     

精密塑料齿轮收缩率对模具型腔尺寸设计的影响

利用Moldflow软件Flow-Shrink模块,研究了精密塑料齿轮不同位置的收缩率,得到指导塑料齿轮模具型腔设计依据。     

塑封电子器件负极端变色原因分析

利用X—RAY光电子能谱仪对125°下,通电15kV,96h后负极一端出现白色物质的塑封电容器进行分析。对比分析性氧化铝结发现,负极一端白色物质为氧化铝富集所致。造成该现象的原因是,环氧塑封料中含有活性氧化铝,由于固化不完全或吸潮导致环氧塑封料中残留水分,残留的水分与活合,在电应力的作用下,有向电源负极迁移的趋势;同时,由于温度效应的存在,塑封树脂软化,加速了水分与活性氧化铝向电源负极迁移的速度,形成了氧化铝在负极端富聚现象,使电容器负极端呈现白色。     

内压作用下斜接管容器塑性极限载荷的数值研究

对三台具有斜接管的圆柱形容器(θ=30°,45°,60°)在内压作用下的塑性变形特征及塑性极限载荷进行了三维非线性有限元数值研究.结果表明:斜接管与筒体截交区纵向截面的锐角侧材料首先进入塑性状态.截交区附近出现明显的塑性变形,纵向截面内发生径向收缩,而横向截面出现明显的径向鼓胀,接管与筒体间的夹角减小.结果同时提供了三台容器的极限载荷值,为该类容器的分析设计提供了依据和参考.