容量法测定PE—淀粉薄膜中淀粉的含量

用四氯化碳溶解样品后与稀酸溶液一起于水浴中加热回流使淀粉进入水相，除掉四氯化碳后在沸水浴中加热回流使淀粉水解为葡萄糖。在加热条件下，以次甲基蓝作指示剂，用样品溶液滴定标定过的碱性酒石酸铜溶液。计算葡萄糖的含量，再换算成淀粉的含量。本法测定结果回收率９９．８１％，变异系数０．１６％，方法准确可靠。     

掺杂C60的聚乙烯基咔唑光导光膜的光电子能谱

采用Ｘ－射线光电子能谱表面分析技术并通过变温手段研究了聚乙烯基咔唑（ＰＶＫ）与Ｃ６０的作用形态，结果表明，ＰＶＫ与Ｃ６０可以形成电荷转移络合物，并且它的形成和解离随着温度的变化是可逆的。ＰＶＫ与Ｃ６０的电荷转移络合物的形成可能是改善ＰＶＫ光电性能的关键所在。     

云母增强聚丙烯的研究

采用云母增强聚丙烯后,PP/云母复合材料与纯聚丙烯相比,模量与弯曲强度均会有较大幅度的提高,但冲击强度下降,甚至低于纯聚丙烯。此外,云母含量较高时,复合材料的流动性下降。基于 PP/云母复合材料所存在的问题,本课题采用聚丙烯-高密度聚乙烯-三元乙丙橡胶/云母(PP-HDPE-EPDM/云母)和聚丙烯-高密度聚乙烯-三元乙丙橡胶-乙烯醋酸乙烯共聚树脂/云母(PP-HDPE-EPDM-EVA/云母)两种共混填充体系,对云母增强聚丙烯进行增韧和提高流动性的研究。通过适当的配比,两种体系均在一定程度上提高了 PP/云母复合材料的冲击韧性和流动性。此外,通过扫描电镜对偶联剂处理云母的界面形态和偶联效果也做了初步的分析工作。     

群子统计理论研究线型酚醛树脂/低密度聚乙烯共混体系固化过程动力学(Ⅲ)

采用群子统计理论建立了固化过程的群子三参数理论模型,得到了相应的三个群子特征参数K,r_1,r_2。其中,K值表征固化反应速度的快慢,而r_1,r_2则用于描述固化过程内部的竞争情况以及固化温度和共混比对于这些竞争情况所产生的影响。     

三种特殊农用地膜效果简介

<正>随着科学技术的日新月异,地膜覆盖技术亦呈现出蓬勃发展的良好势头。据资料介绍,自1981年我区试验推广地膜栽培技术的九年间,我区地膜覆盖面积就达400～500万亩,覆盖作物种类达八种之多。同时,地膜本身亦由单一型向多功能型转变,呈现出良好的发展前景。本文仅就我团近几年来引进试验的三种特殊农用地膜新品种逐一进行简介,以供参考。 1、光敏降解膜:简称光解膜,由石河子塑料制品总厂提供,分别为“91—2#”、“91—3#”、“91—4#”、“91—5#”四个型号。膜厚0.008毫米,膜宽60厘米。设普通膜为对照,共设5个处理,随机排列,重复三次,共15个小区,小区面积36平方米。试验设在148团6连68号棉田,供试品种为新陆早一号。播种铺膜时间为4月25日。观察项目分始裂期、初裂期、大裂期及崩解期四个时期。观察结果表明:四种型号地膜均能光解,且都是先横向裂解,后随裂口增多破裂呈     

Correlation between geometrical parameters of electrical tree and corresponding partial discharge parameters in XLPE

This paper deals with the experimental study on the correlation between the geometrical parameters of electrical tree and corresponding partial discharge (PD) characteristic parameters in the course of electrical tree aging within cross linked polyethylene (XLPE) insulation. The electrical tree aging tests were performed on specimens removed from a section of 220 kV transmission cable. The PD macroscopic characteristic parameters were found to be significantly dependent on the corresponding geometrical parameters of electrical tree channels in the course of aging of XLPE, and different kind of electrical tree has different characteristics, and there is obvious correlation between the type of electrical tree and the pre-applied power-frequency stress. Beside, using regression analysis, the expression of the relation between them were obtained, and from which it can be seen that there is significant nonlinear correlation between geometrical parameters of electrical tree and corresponding PD characteristic parameters in the course of aging of XLPE. Therefore, the aging degree of XLPE can be effectively evaluated by recognizing the changing regularity of the PD rnacroscopic characteristic parameters.     

Effect of addition of poly（ethylene glycol） on electrical conductivity of poly（3,4-ethylenedioxythiophene）-poly（styrenesulfonate） hybrid

By mixing various concentrations of poly (ethylene glycol), a series of poly(3,4-ethylenedioxythiophene)-poly(styeenesuffonate) composite thin films were prepared.The electrical conductivity of the PEDOT-PSS/PEG thin films was measured by the four-pcobe method. Experimental results showed that the inclusion of poly(ethylene glycol) influenced the electrical conductivity of PEDOT-PSS film significantly. With the increase of PEG concentrations, the electrical conductivity sharply increased to reach a maximum and then slowly decreased down. Furthermore, the PEG molecular weight and environment temperature also played important roles on the electrical conductivity of PEDOT-PSS/PEG thin films. A good linear relationship was found between in σDC and T^-1/2 within the entire temperature range detected.     

柴油流动改进剂对柴油中蜡晶形态的影响

采用偏光显微镜研究了自行研制的AVM系列柴油流动改进剂对蜡晶形态的影响.结果表明,柴油流动性改进剂的加入,使柴油中的蜡晶变短变小,阻碍蜡晶相互连接搭桥成网.柴油流动性改进剂的加入量根据柴油组成不同,都应有一个最佳点.对于不同柴油,柴油流动性改进剂中各组成存在一个最佳配比,这一配比下的产物降滤效果最好,微观表现对蜡晶的改善也最明显.大量的数据表明,柴油的蜡晶变化图像与实测的数据相吻合.     

UNIPOL工艺聚乙烯装置粉体静电隐患分析

主要对文献[1]中UNIPOL工艺聚乙烯装置粉体静电隐患进行分析,并提出相应防范措施.     

小尺寸纳米铁颗粒的液相还原控制制备

在液相还原法基础上,以醇水混溶为溶剂,聚乙烯吡咯烷酮(PVP)为稳定剂,通过控制醇和PVP用量合成出粒径在9~20nm的粒径均一、分散性好的纳米铁粒子.通过动态光散射(DLS)、透射电子显微镜(TEM)以及紫外-可见分光光度计等表征手段对醇和PVP在液相合成中的作用以及小尺寸纳米铁的活性进行考察.研究表明,醇的作用主要为抑制纳米铁生长以及使Fe2+均匀分散到PVP中,而PVP则通过其空间位阻作用和静电排斥作用阻止纳米粒子的团聚;随醇中羟基数增加、碳链长度增长,纳米铁粒径逐渐减小;随醇浓度增加,纳米铁粒径减小;同时,随纳米铁尺寸减小,其活性显著增强.