反胶束法合成CdS纳米粒子及其表征

以AOT为保护剂,采用反胶束法合成CdS纳米粒子。利用水洗法洗去保护剂AOT,通过加入不同量的无水乙醇调节分散介质的极性,改变CdS纳米粒子在分散介质中的"溶解度",从而实现不同尺寸粒子的分离。采用紫外-可见(UV-vis)吸收光谱、透射电子显微镜(TEM)、荧光光谱法对其进行表征。     

A Zn(Ⅱ) 5-Aminoisophthalate Coordination Polymer

The title compound, [Zn(AIP)(4,4-bipy)0.5(H2O)]n·0.75nH2O 1, was synthesized via the hydrothermal reaction of Zn(OAc)2 with 5-aminoisophthalic acid (H2AIP) and characterized by elemental analysis and infrared spectra. The complex crystallizes in monoclinic system, space group P21/c with a = 12.672(1), b = 7.6557(4), c = 16.181(1) (A),β = 109.187(2)o, V = 1482.6(2) (A)3, Z = 1, C52H52N8O23Zn4, Mr = 1418.58, Dc = 1.589 g/cm3, F(000) = 724 and μ(MoKα) = 1.685mm-1. The final R = 0.0702 and wR = 0.1524 for 1847 observed reflections with Ⅰ ＞ 2σ(I), and R = 0.0873 and wR = 0.1664 for all data. X-ray diffraction studies reveal that the title compound has an interesting 2D microporous architecture with guest water molecules inside the channel.     

Oxide Nanofibers as Catalysts Toward Energy Conversion and Environmental Protection

Ultrathin oxide nanofibers are widely used in an array of catalytic applications toward energy conversion and environmental protection. Remarkable progress has been made with regard to the development of engineering oxide nanofibers into unique structures to suit or enable various functions. We aim to provide a comprehensive overview of oxide nanofibers, including the structure engineering, derivates, assemblies and their applications. We begin with a brief introduction to the production of nanofibers with diversified compositions, structures and properties, followed by discussions of the wet-chemistry derivates. Afterward, we discuss the applications of catalytic oxide nanofibers, including electrocata-lysis, photocatalysis and thermal-catalysis. Then we highlight the most significant role of oxide nanofibers as catalyst support for the immobilization of metal nanoparticles. Moreover, we showcase the advanced assemblies based on oxide nanofibers, including their use as multi-functional membranes and foams. In the end, we offer perspectives on the challenges, opportunities and new directions for future development.     

经典弹性力学与应用力学方法

通过对经典弹性力学半反演法的特点与应用力学方法的特点的对比,阐明应用力学方法是在经典弹性力学半反演法的基础上发展出来的,指出应用力学方法源自经典弹性力学．讨论了在弹性力学的教学过程中,突出半反演法和应用力学方法之间的关联,会产生很好的教学效果．     

大学化学综合实验:三草酸合铁(Ⅲ)酸钾的制备和结构表征*

介绍一个综合化学实验,主要内容为用三氯化铁和草酸钾为原料水相制备三草酸合铁(Ⅲ)酸钾并对其结构进行表征。测定了配合物的组成和配离子电荷,重点研究了配体和配合物的电子光谱和红外光谱,测定了配合物的磁矩、XRD和热稳定性等。实验结果表明,制得的配合物组成为K3[Fe(C2O4)3]·3H2O,产率90.0%;电子光谱吸收峰数值小于350~400 nm,是由配体到中心离子的电子跃迁产生的;红外光谱归属推断配合物中存在双齿或螯合的草酸根;配合物磁矩为5.16 B.M.,中心离子Fe3+的杂化态为sp3d2,配合物为高自旋的外轨配合物,八面体结构。通过该实验,学生能够理解配合物制备、组成测定和结构表征系列实验的原理,熟悉各种现代测试技术,激发学生对科学研究的兴趣,培养学生综合实验能力和创新能力。     

有关Clifford矩阵群的几个离散性判别准则

研究了Clifford矩阵变换群的离散性质,给出了几个判别离散群的不等式和定理.     

基于裂纹附加模态Timoshenko梁的裂纹损伤识别

将梁中横向裂纹等效为无质量扭转弹簧，并忽略其对梁剪切变形的影响，得到的具有任意裂纹数目Timoshenko 梁自振模态的统一显示解析表达式．将裂纹梁的自振模态分为基本模态和裂纹附加模态，利用最小二乘拟合，建立了利用裂纹附加模态函数的梁裂纹损伤识别方法．通过数值模拟开展了简支单裂纹梁以及悬臂和固支双裂纹梁等的裂纹损伤识别，考察了测量误差对损伤识别的影响，数值结果表明本文所提出的裂纹损伤识别方法对裂纹位置的识别精度高于对裂纹损伤程度的识别精度；随着测量误差的增加，裂纹位置及裂纹损伤程度的识别误差增加，但仍在可接受的范围内，故该裂纹损伤识别方法在实际工程中具有一定的应用价值．     

一台小型强流脉冲电子束加速器

本文介绍了一台供研究准分子气体激光器用的强流脉冲电子束加速器,其输出电压为500kV,束流50kA,脉冲宽度60ns,运行稳定,控制可靠,是一台小型可移动的电子加速器。文中还给出了它的结构参数,主要特点和调试结果。