微型吸附柱富集-高效液相色谱法测定水中痕量N-亚硝胺

目前,从水样中提取痕量N-亚硝胺的技术已有不少,但大多未摆脱繁琐,冗长的蒸发浓缩操作。而且常规方法取样量大,造成采样、运输、贮存上的困难。文献用微型活性碳柱富集小体积水样,简化了前处理过程。本文则在文献的基础上,较全面地研究     

一类时滞抛物方程的振动准则

本文研究发如下具连续分布滞量的时滞抛物型偏微方程的振动性，给出了此类方程的若干新的振动准则。     

Medium-Range Order Structure and Fragility of Superheated Melts of Amorphous CuHf Alloys

The structural factors of amorphous CuHf alloys at different temperatures are determined by using a high temperature x-ray diffractometer. It is found that not only the short-range order structure but also the medium-range order structure exists in amorphous CuHf alloys. The dynamic viscosities of CuHf alloy melts are measured by a torsional oscillation viscometer. The fragility of superheated melts of CuHf alloys is calculated based on the viscosity data. The experimental results show that the glass-forming ability of the CuHf alloys is closely related to the fragility of their superheated melt. The relationship between the medium-range order structures and the fragility of superheated melts has also been established in amorphous CuHf alloys. In contrast to the fragility of supercooled liquids, the fragility of superheated liquids promises a better approach to reflecting the dynamics of glass forming liquids.     

A Novel Nano-Grating Structure of Polarizing Beam Splitters

A metal wire nanograting is fabricated and used as a polarizing beam splitter that reflects TE polarization and transmits TM polarization. The metal wire nanograting is based on a fully optimized design structure that consists of not only the core nanowire metal grid but also the substrate nanograting. The substrate nanograting is designed to provide better performance for both TM and TE polarizations. We fabricate metal-stripe gratings on a glass substrate using nanoimprint lithography and reactive ion etching process. A detailed investigation of the polarization effect at 1550 nm wavelength is carried out with the theoretical analysis and experimental results. The polarizing beam splitter has uniform performance with wide variations in the incident angle （±25） and has high efficiency for both the reflected and the transmitted beams.     

激光散斑图样的光流场分析研究

提出了一种基于动态图像处理的新的电子散斑计量方法－光流场分析法，从新的角度出发讨论了运用图像序列分析的概念秋解决散斑图样测量的可行性和简便性。并且解决了当散斑图像不满足进行光流场分析的约束条件时的测量问题，即通过多通道的图像处理方法来改变图像连续特性，从而扩大了测量范围。     

苯乙烯和顺丁烯二酸酐共聚物的红外光谱定量分析(Ⅱ)

前一工作介绍了在用溶液法中采用自身内标归一化法,提高了方法的精密度。但因溶样和洗池等手续,毕竟不如溴化钾压片法更为简便、快速。将树脂直接用溴化钾压片进行定量分析,往往由于树脂的状态以及压片条件而影响红外透过率的正确测量。本工作对其中的一些影响因素以及结果的计算作了探讨。实验部分所用的红外分光光度计为Perkin-     

用于全息存贮的全息散斑相移透镜

本文利用全息透镜和激光散斑的特性,提出一种专门用于信息存贮的全息散斑相移透镜。并给出了这种平面型光学元件的制作过程及实验结果。     

用HPLC法对农药杀螟松中杂质的分离和定量

杀螟松是当前高效低毒的重要农药之一,但在生产过程中可能产生一些高毒性杂质。本文在前人报导的基础上,采用Micropak-MCH5反相柱对流动相进行了选择,建立了一个适宜于工厂的分析方法。一、实验方法 1.试剂:流动相,乙腈、甲醇均为分析纯,水为去离子水重蒸,使用前均经0.45μ滤膜过滤。样品和标样均由宁波化工所提供。I:3-甲基4-硝基苯酚,Ⅱ:杀螟氧磷,Ⅲ:硫甲基杀螟松,Ⅳ:杀螟松,Ⅴ:双硝基杀螟松。     

类比推理与立体几何教学

类比推理是由特殊到特殊的推理形式。它是数学发现的重要方法。特别对几何的教与学是有效的。开普勒曾说:“我赞成类比胜过其它的一切,它是我最可信赖的。它知道自然的一切奥秘,并且在几何中它经常是有效的。”因此在立体几何教学,类比联想是引导学生发现结