氢氧化铝对有机硅电子灌封胶性能的影响

以端乙烯基硅油为基胶、含氢硅油为交联剂、γ-甲基丙烯酰氧基丙基三甲氧基硅烷(KH-570)为表面处理剂、Al(OH)3或Al(OH)3/铂络合物为阻燃剂,制备阻燃型有机硅电子灌封胶。研究结果表明:对Al(OH)3表面进行处理、降低其粒径、增加其含量、Al(OH)3/铂络合物并用等均有利于提升灌封胶的阻燃性能;当w(KH-570)=0.5%[相对于Al(OH)3质量而言]、Al(OH)3的平均粒径为2.6μm、m(5.0μmAl2O3):m[2.6μm Al(OH)3]=160:40和w(铂络合物)=0.002%(相对于基胶质量而言)时,可制得阻燃性优异的有机硅电子灌封胶。     

Melt Functionalization of Ethylene-Propylene Copolymer: Structural Investigation

An ethylene-propylene copolymer (EPM) has been functionalized with acrylic acid (AA) by means of a radical-initiated melt process. Different degrees of grafting have been obtained by varying the overall composition of the reaction mixture. The influence of the grafting degree on the structure has been investigated by differential scanning calorimetry (DSC), Fourier-transform infrared analysis (FTIR), and wide-angle x-ray scattering (WAXS) techniques. The results of the structural investigations suggest that the grafting preferentially occurs onto the ethylene sequences of EPM. After acrylic acid was grafted onto EPM, the grafted AA acted as nucleation agent; it caused an increase of crystallization temperature of propylene sequences of EPM-g-AA.     

BF3-AlCl3在C5石油树脂中的应用

裂解乙烯C5馏分含有大量线性不饱和分子和质量分数超过16%的环戊二烯,用BF3做催化剂可以得到浅色石油树脂,但当环戊二烯含量高时一般需先除去,得到的树脂软化点不是很高。本文以乙烯装置副产Ｃ5馏分为原料,考察了BF3与AlCl3质量比、催化剂用量、反应温度对Ｃ5石油树脂软化点及收率的影响。实验结果表明,三氟化硼和无水三氯化铝最佳质量比为7∶3,催化剂总用量占原料总质量的2%,在反应温度为40 ℃,反应时间为4 h时,可得到收率为56.6%（质量分数）,色度为6～7,软化点为101 ℃的浅色C5石油树脂,其直接可用于油墨、橡胶等中。     

Conversion measurement in polyethylene/peroxide coupling system under steady shear flow

The coupling reaction of melt linear low density polyethylene (LLDPE) initiated by dicumyl peroxide (DCP) in steady shear flow field was investigated. The conversion of DCP was measured by electron spin resonance (ESR) and chemical titration. An absolute method was proposed to calculate the actual conversion of DCP from rheological data. The coupling efficiency of DCP was obtained from those analyses, which was shown to increase at first, reach a maximum and then decrease in the end stage. A linear relationship between the coupling efficiency of DCP and the concentration of macroradicals was also found in the experiments.     

微机控制潜水电泵试验台优化设计的研究

本文在潜水电泵试验台系统分析的基础上,利用技术经济学的价值工程法建立了潜水电泵试验台优化判据和优化设计的数学模型。首次用数值求解的方法求得最佳仪表组合方案。为潜水电泵试验台的设计提供了理论依据。     

基于回归分析的汽车扶手箱下盖板注射成型工艺优化

以汽车扶手箱下盖板为研究对象,研究了保压压力、保压时、冷却时间、模具温度以及注塑温度五个注塑工艺因素对大型薄壁塑料件翘曲变形的影响.利用拉丁超立方抽样设计试验方案,基于Moldflow软件确定浇口位置、设置浇注系统和冷却系统,并对注射成型过程进行模拟仿真.通过对25组试验进行回归分析获得二阶回归模型,并结合遗传算法全局...     

A Novel Molecularly Imprinted Core?CShell Chemiluminescence Sensor: Preparation and Pendimethalin Recognition

Novel molecularly imprinted core?Cshell microspheres were synthesized using hollow silica microspheres as the core. Because of the molecularly imprinted core?Cshell microspheres, the effective binding sites at the surface of the shells were sharply increased; and, the recognition capability for template molecules was greatly improved. Based on this, a novel chemiluminescence sensor was established and successfully applied in the detection of trace pendimethalin in foodstuffs. The proposed sensor exhibited excellent selectivity, good sensitivity and simple operation. High throughput sample detection was realized with satisfactory results.     

沈阳仪表科学研究院物理清洗装备介绍

介绍了沈阳仪表科学研究院物理清洗装备的开发现状及未来发展规划,所涉及的清洗装备包括清洗机、清管器、电脉冲、真空排污设备、大型清洗系统等多种物理清洗装备,作业领域覆盖多个行业.     

Preparation and mechanical properties of high‐performance short ramie fiber‐reinforced polypropylene composites

Short ramie fiber (RF) was used to reinforce the polypropylene (PP). The composites were prepared in a twin‐screw extruder followed by injection molding. The experimental results showed that both the strength and the modulus of the composites increase considerably with increasing RF content. The tensile strength and flexural strength are as high as 67 and 80 MPa by the incorporation of ramie up to 30 wt %. To the best of our knowledge, this is one of the best results for short natural fiber‐reinforced PP composites. However, the preparation method in this study is more simple and economic. This short RF‐reinforced PP composites extend the application field for short‐nature fiber‐reinforced PP composites. Morphological analysis revealed that it is the high aspect ratio of the fiber and good interfacial compatibility that result in the high performance of the composites. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2011     

光折变晶体的光衍射机制研究

本文研究了光折变晶体的自衍射光斑,它是入射光束及其在晶体后表面的反射光束与由晶体缺陷所致散射光的简并四波混频过程,其锥角由位相匹配条件△K=0确定,并可用Ewald球作图法解出.实验和理论分析表明上述反射光束对光折变的自衍射光产生是有作用的.