纯ZrO_2纳米粒子结构的拉曼光谱研究

本文对粒径在５８～１０ｎｍ范围内不同粒度的纯ＺｒＯ＿２粒子进行了拉曼散射光谱研究。结果表明，粒子的点阵结构受表面效应的影响，粒径的减小，粒子表面层结构严重畸变，但仍是有序的结构。同时，表面效应将进一步引起ＺｒＯ＿２粒子点阵结构变化，在室温下，使单斜相的粒子自发地转变为四方相结构。ＺｒＯ＿２粒子由单斜相向四方相转变的临界直径为１５ｎｍ。     

A novel high-resolution interference spectrometer

A novel precision wavemeter is presented with a resolution of better than 0·01 nm. A Sagnac interferometer with two diffraction gratings forms the basis of the instrument. Using spatial heterodyning techniques and a CCD camera/frame grabber data acquisition system allows fast computer control and power spectrum analysis. The mode structure and mode hopping characteristics of a typical laser diode were examined as a function of diode injection current.     

映谱仪常见故障的维修方法

映谱仪在使用一段时间后，往往会出现光路成像不清，机械可调部分失灵等故障，文中主要介绍了这些故障的排除方法。     

一种反光发光复合标牌材料的研究

反光发光复合标牌,不仅能将光源方向的入射光线回归反射向光源方向,具有反光特性.还能将光源中大量的红外光转换成可见光,具有发光特性.从而使标牌的亮度和可视距离得到提高.     

红外光谱法测定3,5-二叔丁基甲苯

用庚烷做溶剂，红外光谱法定量测定3，5－二叔丁基甲苯，其方法选择性好、简单、快速。在0.042-0.292g/mL范围内与吸光度呈现良好的线性。其线性方程为A＝0.126＋0.4007C,相关系数r=0.997用t-检验法对本方法进行检验，此法准确、可靠。实样测定，结果令人满意。     

第一过渡族自由离子光谱与最优化3d电子径向波函数

通过对第一过渡族自由离子光谱参数实验值的线性分析和计算，得到了具有系统性和规律性的最优化３ｄ电子径向波函数。并用最优化３ｄ电子径向波函数计算了自由离子光谱，理论计算与实验进行了比较。     

用电子探针定量分析超轻元素中的几个问题

碳，硼，氮及氧等元素在电子探针分析中常称之为超轻元素，这些元素的定量分析还存在许多包括测量和定量修正方面的困难。本文就质量吸收系数的不准确，超轻元素谱线的化学位移，及重元素的Ｌ，Ｍ及Ｎ系谱线对其干扰等方面的问题进行研究和讨论，并分别提出了解决这些问题的方法。选择合适的标样是获得准确定量分析结果的关键。     

基于支持向量机测定水质中硝酸盐含量

针对水质中被测物硝酸盐与干扰物铁离子、铬离子紫外吸收谱线严重重叠的问题,将支持向量机应用于混合重叠光谱分析中,利用核函数将重叠的光谱数据进行高维空间变换后求得SVM回归模型,实现硝酸盐含量的光谱检测。实验结果表明:硝酸盐浓度在0.5—10mg/L范围内,所测得含量的最大相对误差为3.2%;平均回收率为100.9%,本法与传统的方法相比,要求条件较低,不需要物理或化学的分离,分析速度快,有望应用于在线监测污水中硝酸盐的含量。     

A simple proof of the spectral excess theorem for distance-regular graphs

The spectral excess theorem provides a quasi-spectral characterization for a (regular) graph Γ with d+1 distinct eigenvalues to be distance-regular graph, in terms of the excess (number of vertices at distance d) of each of its vertices. The original approach, due to Fiol and Garriga in 1997, was obtained by using a local approach, so giving a characterization of the so-called pseudo-distance-regularity around a vertex. In this paper we present a new simple projection method based in a global point of view, and where the mean excess plays an essential role.     

Deleting Vertices and Interlacing Laplacian Eigenvalues

The authors obtain an interlacing relation between the Laplacian spectra of a graph G and its subgraph G - U, which is obtained from G by deleting all the vertices in the vertex subset U together with their incident edges. Also, some applications of this interlacing property are explored and this interlacing property is extended to the edge weighted graphs.