A 3D EFFECT IN THE WEDGE ADHESION TEST: APPLICATION OF SPECKLE INTERFEROMETRY

The wedge test is of considerable use for evaluating adhesion between two bonded rigid substrates. In its (usual) static form, release of elastic strain energy is equated to effective adhesion energy during crack growth. However, the test is usually treated as two-dimensional. In fact, it is really three-dimensional due to anticlastic bending effects of the bent beam(s) during crack propagation.

We studied a composite material/epoxy/aluminium alloy system and observed a curved crack front during propagation. This leads to doubt as to the value of crack length to be inserted in the adhesion energy formula. In addition, by using the highly sensitive technique of speckle interferometry, it was possible to study anticlastic bending effects in a quantitative manner. Far from the crack front, agreement between theory and experimental is good, yet work remains to be done to understand the zone near the fracture zone.     

超声波在制备nm SiO_2/环氧树脂复合材料中的应用

本文通过溶液共混的方法制备了ｎｍ　 ＳｉＯ_２／环氧树脂复合材料,并利用 ＳＥＭ、 ＴＧ拉伸测试、冲击测试等方法对其结构和力学性能进行了研究。为了改善ｎｍ ＳｉＯ_２在环氧树脂中的分散及其两相间作用,作者在制备该复合材料的过程中运用超声波对分散体系进行了处理,并取得了良好的效果。     

S4实验在聚乙烯管道中的应用

介绍了模拟聚乙烯压力管道的快速裂纹扩展的小尺寸稳定实验－－S4实验，该实验方法可以代替全尺寸实验获得压力管道的止裂性能指标，并应用到工程中去，主要介绍了S4实验装置与实验原理，温度、管壁厚度等因素对止裂性能的影响，并对S4实验结果和全尺寸实验结果进行了比较。     

ABS阻燃性能测试中差热/热重-红外光谱技术的应用

分别采用氧指数和差热、热重－红外光谱技术对常用的ABS材料进行测试。结果表明，试验样品差热数据和氧指数数据有对应关系。差热／热重－红外光谱联用可以观测到ABS热分解过程和分解产物，纯ABS和阻燃ABS的分解过程明显不同。通过差热／热重－红外光谱数据可以获取更多的材料在高温下的变化信息，从而有利于对材料阻燃性能和阻燃危寄性进行预测和判断。     

基于三点弯曲实验的混凝土抗拉软化关系的求解方法

确立了分别基于开裂强度准则和断裂韧性准则的由三点弯曲实验确定混凝土材料抗拉软化关系的方法.该方法应用扩展的黏聚裂纹模型,通过使模拟的荷载一裂纹口张开位移(stress-crack width relationship,Load-CMOD,P-CMOD)曲线与三点弯曲实验获得的P-CMOD曲线吻合来确定相应的混凝土抗拉软化关系参数.求解中的所有参数均由三点弯曲实验结果确定,其优点是只需用简单的位移控制试验机完成弯曲实验,与单轴拉伸实验相比,实验成功率更高、更容易实现.     

论陶瓷现代化产业建设发展中电脑三维技术的应用

在科学技术高度发展的今天,传统的制瓷行业也受到了冲击,大量的现代化科学技术正在介入到我们的传统制瓷行业当中,而我们所熟悉的电脑三维成型技术在陶瓷现代化产业建设中更是扮演了一个非常重要的角色。从实际的案例着手,分析了样品制作环节中电脑三维技术应用的必要性,得出了陶瓷设计中应用电脑三维技术符合陶瓷现代化产业建设发展的结论。     

硅胶固载光敏剂的合成及其在反式维生素D3光敏异构化为顺式维生素D3中的应用

采用丙二酸作为连接,针9－蒽甲醇连接到硅胶上生成硅胶固载的光敏剂。利用此因相光敏剂分别在乙醇和甲苯溶液中敏化反式维生素D3。实验结果表明，此固相光敏剂能够有效地敏化反式维生素D3为顺式维生素D3的反应，并且非常容易从反应体系中分离出来。     

THE INFLUENCE OF PROCESS PARAMETERS ON THE INTERFACIAL CHEMISTRY OF γ-GPS ON ALUMINIUM: A REVIEW

Within the “International Collaborative Programme on Organosilane Adhesion Promoters” (ICOSAP), scientists from the U.S. and Europe contributed to the understanding of an organosilane primer process, based on an aqueous solution of γ-glycidoxypropyl trimethoxysilane (γ-GPS), used currently for aerospace repair purposes. Parameters such as temperature of cure, ageing time, and concentration of the aqueous solution have been investigated, and this work reviews the effect that each variable has on the process, and the resulting integrity of the GPS/aluminium interface. The aim of the work was to provide a more environmentally friendly replacement for pretreatments containing Cr(VI) that are currently used, such as chromic acid anodising and acid etching employed for the structural adhesive bonding of aluminium.

The formation of covalent interfacial bonding is shown to be a function of the hydrolysis and condensation of the silane molecules in solution as well as the type of solvent used. The curing temperature of the aqueous film on the aluminium is also shown to have an effect on the chemistry of the resulting primer film and its efficacy as an adhesion promoter. All these parameters must be optimised to obtain durability that matches that obtained by a phosphoric acid anodising pretreatment. This work reports on the various studies performed towards this aim carried out within the remit of the ICOSAP initiative, with a particular emphasis on the interfacial chemistry between γ-GPS and the aluminium substrate, and indicates the manner in which the results point the way towards a viable, environmentally friendly pretreatment for the adhesive bonding of aluminium for aerospaceapplications.     

内蒙古地产紫沙参毒性及药效实验研究 2. 紫沙参毒性及镇咳、祛痰药效实验研究

１．通过紫沙参水提物、醇提物经口给药和腹腔注射给药的最大耐受量试验,结果显示紫沙参水提物和醇提物均属基本无毒范围。２．以紫沙参的乙醇提取物、乙酸乙酯提取物作为受试物,观察其连续多次经口给药的镇咳、祛痰作用,结果显示紫沙参镇咳、祛痰作用显著     

TECHNICAL NOTE: THE EFFECT OF SLIP ON THE FLOW IN A ROTATING CHANNEL

Slip flow occurs in a wide variety of practical chemical engineering processes. This work models, for the first time, the interaction of surface slip and system rotation normal to the flow direction. It is found that the flow fields are affected considerably. For Poiseuille flow, slip increases the longitudinal flow rate at low rotation, but decreases it at high rotation. For Couette flow, slip decreases the longitudinal drag. The solutions are also exact solutions of the Navier-Stokes equations.     

STUDY OF BONDED PLASMA-TREATED POLYETHERIMIDE COMPONENTS FOR POWER INTEGRATION: DURABILITY IN A HOT/WET ENVIRONMENT

This work deals with the study of the durability, in a hot/wet environment, of structural adhesively bonded polyetherimide (PEI) assemblies used in power electronics packaging technology. An overall approach is proposed, for which the epoxy joint-PEI substrates assembly on the one hand, and the adhesive system components (substrate surface and bulk adhesive) on the other hand, are studied separately with different analytical techniques. The first part of this work was devoted to the substrate surface state and to its modification using a cold plasma treatment of the PEI surface. Then for chosen parameters (power, duration) contact angle measurements indicated an increased surface tension resulting from surface decontamination (removal of release agent and carbon contaminants) and from the creation of polar species, such as esters or carboxylic acid groups, on the PEI surface (XPS analyses). The second part of this study concerned the bulk adhesive ageing in an ethylene glycol-water solution at 70°C. Mass uptake measurements versus time showed the liquid diffusion in the bulk adhesive associated with a microscopic damage of the epoxy system. An overall plasticizing of the adhesive with a considerable decay of the α-transition temperature of one of the two adhesive epoxy-amine networks (TGDDM-BAPP) was also highlighted using rheometry. However, in these ageing conditions, the adhesive glassy modulus decreases slighty because of the thermomechanical stability of the other epoxy network. In the third part, the asymmetric wedge test showed the beneficial effect of the cold plasma treatment on the epoxy/PEI interface durability in the aggressive medium.     

CALORIMETRIC STUDIES OF THE SYNERGISTIC EFFECT: THE REACTION OF UO2, Ln(PMBP)3 AND Th(PMBP)4 WITH TOPO IN NITROBENZENE

Titration calorimetry has been used to measure the thermodynamics of reaction in nitrobenzene solution of PMBP complexes of lanthanides, uranyl and thorium with TOPO. The extraction from aqueous solution into chloroform solutions of PMBP and TOPO was also studied. The role of hydration effects in the extraction and synergistic reactions is discussed based on the enthalpy and entropy values of the processes. Synergism is found to result primarily from the large, positive entropies caused by the dehydration resulting from adduct addition to the PMBP complexes.