BEPCII直线注入器的尾场效应

BEPCII直线注入器中的强流、短束团的尾场效应将损害束流的性能.用分析解和数值模拟计算的方法,系统地研究了尾场对纵向和径向束流动力学的影响,包括单束团的短程尾场和多束团的长程尾场对束流能量、能散、发射度、轨道和初级电子束在正电子产生靶上束斑尺寸的影响等.研究了有效抑制这些尾场效应的措施     

闭曲面上C0流有伪轨跟踪性质的条件

给出了闭曲面上奇点孤立的C⁰流有伪轨跟踪性质的充分必要条件     

Synthesis of ZnAl2O4/α-Al2O3 complex substrates and growth of GaN films

With the solid phase reaction between pulsed-laser-deposited (PLD) ZnOfilm and α-Al2O3 substrate, ZnAl2O4/α-Al2O3 complex substrates were synthesized. X-ray diffraction (XRD) spectra show that as the reaction proceeds, ZnAl2O4 changes from the initial (111)-oriented single crystal to poly-crystal, and then to inadequate (111) orientation. Corresponding scanning electron microscope (SEM)images indicate that the surface morphology of ZnAl2O4 transforms from uniform islands to stick structures, and then to bulgy-line structures. In addition, XRDspectra present that ZnAl2O4 prepared at low temperature is unstable at the environment of higher temperature. On the as-obtained ZnAl2O4/α-Al2O3 substrates, GaN films were grown without any nitride buffer using light-radiation heating low-pressure MOCVD (LRH-LP-MOCVD). XRD spectra indicate that GaN film on this kind of complex substrate changes from c-axis single crystal to poly-crystal as ZnAl2O4 layer is thickened. For the single crystal GaN, its full width at half maximum (FWHM) of X-ray rocking curve is 0.4°. Results indicate that islands on thin ZnAl2O4 layer can promote nucleation at initial stage of GaN growth, which leadsto the (0001)-oriented GaN film.     

连续树映射非游荡集的拓扑结构

本文研究树（即不含有圈的一维紧致连通的分支流形）上连续自映射的非游荡集的拓扑结构．证明了孤立的周期点都是孤立的非游荡点；具有无限轨道的非游荡点集的聚点都是周期点集的二阶聚点，以及ω－极限集的导集等于周期点集的导集和非游荡集的二阶导集等于周期点集的二阶导集．     

用复印量探测中学数学主要刊物

中学数学杂志在我国千姿百态、繁花似锦的期刊之林中是一株新秀。它主要登载我国数学研究工作者、广大中学数学教育工作者撰写的中学数学教育科研论文,教学经验、体会、解题思维和方法等文章。它提倡不同观点的自由讨论,文章具有一定独特的创见和特色,反映出一定时期我国中学数学教育思想和中学数学教学研究的最新水平和成果。     

希土脯氨酸配合物的合成和性质研究

通过希土氯化物与L-脯氨酸反应,制得了四种新的希土脯氨酸固体配合物。其通式为:Ln(prol)Cl₃·nH₂O(Ln=Y、La、Sm和Er).用化学分析、电导测定、热重分析、差热分析、红外光谱和核磁共振氢谱,确定了产物的组成,讨论了金属-配体的化学键性质。     

STUDIES ON ION IMPLANTATION AND ELECTRICAL PROPERTIES OF POLYACETYLENE FILMS

The effects of ion implantation on ployacetylene films PA have been studied with Ar~+, Fe~+, C1~+, I~+, Na~+ and K~+ ions in the energy range of 15—30 keV. The changes of PA films in the electrical conductivity, due to chemical doping and ion implantation in relation to their structure and depth profiles of impurities, were measured through infrared (ATR/FTIK), Rutherford backscattering spectrometry (RBS) and the four probe technique. In all cases, ion implantation of active ions exhibits the same effects as chemical doping. The formation of p-n junction is observed at the interface of implanted region and chemical doped PA substrate. The mechanism of interaction process between ion beam and polymer is also discussed.     

C60的发现和Fullerene化学——1996年诺贝尔化学奖简介

本文简单介绍了１９９６诺贝化学奖获得者，以及他们发现Ｃ６０和十多年以来Ｆｕｌｌｅｒｅｎｅ领域的研究概况。     

以β-环糊精及其衍生物为手性选择剂毛细管电泳拆分几种药物的旋光对映体

在毛细管电泳中，采用β－环糊精（β－ＣＤ）及其衍生物为手性选择剂对扑尔敏、异丙嗪、二氧异丙嗪和氧氟沙星对映体进行了分离。优化了分离条件；讨论了环糊精空腔边缘与溶．质分子作用的基团的种类和分离效果的联系，通过计算手性分离的热力学常数比较了不同手性选择剂对扑尔敏对映体的分离能力。最后，讨论了乙腈在手性分离中的作用。