离子注入过程中金属间化合物的生长模型

给出了在离子注入过程中金属间化合物生长的一个数学模型。在准静态近似下,利用分区处理和引入快、慢变量的方法,给出了该模型的近似解。得到了生长速率与微缺密度、注量率、热发射率之间的定量关系。     

Al_xGa_(1-x)As中3d过渡金属杂质深能级

由于Al_xGa_(1-x)As半导体合金在光电子学中得到重要的应用,故它的各种物理性质引起人们广泛的兴趣,其中包括各种深浅杂质的电子结构。但是,相对而言,人们对Al_xGa_(1-x)As中3d过渡金属杂质电子态了解还很不够,对不少3d杂质实验研究还很缺乏,尤其是由于3d杂质复杂的多电子特性,迄今还没有见到关于Al_xGa_(1-x)As中3d杂质深能级的详细理论研究。另外,了解这样一种典型的阳离子准二元合金中3d过渡金属杂质深能级随合金成份的变化趋     

Adhesion of PBO Fiber in Epoxy Composites

The high mechanical and thermal performance of poly p-phenylene- 2, 6-benzobisoxazole ( PBO ) fiber provides great potential applications as reinforcement fibers for composites. A composite of PBO fiber and epoxy resin has excellent electrical insulation properties, therefore, it is considered to be the best choice for the reinforcement in high magnetic field coils for pulsed magnetic fields up to 100 T.However, poor adhesion between PBO fiber and matrix is found because of the chemically inactive and/or relatively smooth surface of the reinforcement fiber preventing efficient chemical bonding in the interface, which is a challenging issue to improve mechanical properties. Here, we report the surface modification of PBO fibers by ultraviolet (UV)irradiation, O2 and NH3 plasma, as well as acidic treatments. The interfacial adhesion strength values of all the treatments show the similar level as determined for aramid fibers by pull-out tests, a significant impact on fibermatrix-adhesion was not achieved. The surface free energy and roughness are increased for both sized and extracted fibers after plasma treatments together with maleic anhydride grafting. The sized fiber shows marginal improvement in adhesion strength and no change in fiber tensile strength because of the barrier effect of the finish.For the extracted fiber, different surface treatments either show no apparent effect or cause reduction in adhesion strength. Atomic force microscopy (AFM) topography analysis of the fracture surfaces proved adhesive failure at the fiber surface. The fiber surface roughness is increased and more surface flaws are induced, which could result in coarse interface structures when the treated fiber surface has no adequate wetting and functional groups. The adhesion failure is further confirmed by similar adhesion strength and compression shear strength values when the fiber was embedded in various epoxy resins with different temperature behavior. The tensile strength of fiber is sensitive to surface treatment conditions as revealed by a bimodal Weibull statistical distribution analysis. Considerable strength reduction occurred, particularly for cases of acidic and plasma treatments, while UV irradiation shows the better ability to retain fiber strength.     

提高获得新颖化合物机率的方法初探

本文从微生物材料的选择和工作方法的选择两个方面对如何提高获得新颖化合物机率的方法进行了探讨,并对国内外的研究动态进行简要介绍.     

炔烃的锆烷基化加成反应:合成多取代烯烃

本文报道了锆烯络合物对炔烃的烷基化加成,合成多取代烯烃,产率较高。     

应用2-氨基-4,6-二甲氧基嘧啶合成十一种偶氮化合物

以2-氨基-4,6-二甲氧基嘧啶为底物,先对其进行重氮化,再与一些活性芳环偶联,得到十一种偶氮化合物.经以不同有机溶剂重结晶和/或薄层谱分析提纯,测定了溶点及光谱数据.     

杂多钨酸及其盐对碳钢的缓蚀作用

采用失重法研究了部分杂多化合物在水介质中对碳钢的缓蚀作用。实验结果表明，所研究的１１种杂多化合物对碳钢均具有一定的缓蚀作用。其中，Ｎａ８Ｈ［ＰＷ９Ｏ３４］·ｘＨ２Ｏ和Ｎａ１０［α－ＳｉＷ９Ｏ３４］·ｘＨ２Ｏ等缺位化合物的缓蚀效果较好，它们的最佳缓蚀浓度分别为１０５０～１１５０ｍｇ／Ｌ和５００～６００ｍｇ／Ｌ。从杂多化合物的性质及实验过程所发生的现象推测，所研究的杂多化合物为复合型缓蚀剂     

柠檬酸钛（Ⅳ）化合物的合成和热性质研究

四氯化钛与柠檬酸反应，制得新的固态化合物Ｔｉ２Ｏ２（ＯＨ）２（Ｃ６Ｈ５Ｏ７）·３Ｈ２Ｏ．通过元素分析和容量滴定法确定了化合物的组成；用Ｘ射线粉末衍射，ＩＲ等对其结构进行了表征；用ＴＧ和ＤＴＡ研究了化合物在空气氛下的热分解特性，计算机求解化合物热分解过程的反应级数ｎ，活化能Ｅａ，频率因子Ａ，焓变ΔｒＨ和熵变ΔｒＳ．