The Cross Link of Surface Enhanced Raman Scattering with Surface Science and Nanoscale Science

The discovery of surface enhanced Raman scattering (SERS) in the mid-1970s impacted on the surface science community because of its remarkably high and unique surface sensitivity. Surface roughness in scale of 10~100 nm have been found necessary to produce the giant SERS signal. In this paper we will show that SERS is indeed one of the important phenomena not only in surface science but also in nanoscale science^[1].     

THE ACTION OF THE LINEAR CHARACTER GROUP ON THE SET OF NON-LINEAR IRREDUCIBLE CHARACTERS THE ACTION OF THE LINEAR CHARACTER GROUP ON THE SET OF NON-LINEAR IRREDUCIBLE CHARACTERS

1. Notations and Basic ResultsLet G be a finite nonabelian group. Then frs(G/G') is an abelian group under themultiplication of characters and acts on the set of non-linear irreducible characters of G viathe multiplication of characters. The purpose of this paper is to investigate this action. Asan application of our theoryl in the end of Section 3 we give the classification of groupshaving exactly three non-linear irreducible caracters.All groups in the paper are finite. For a factor grou…     

污染数据回归分析中参数的最小一乘估计

考虑简单回归模型：ｙｉ＝ｘ′ｉβ＋ｅｉ,ｉ＝１,…,ｎ。其中Ｅｅｉ＝０,Ｅｅ＾２ｉ＝σ＾２１。假设ｙ１,ｙ２,…,ｙｎ受到另一独立同分布随机变量序列μ１,μ,…,μｎ的污染,我们仅能观察到污染数据ｙ＾＊ｉ＝（１－ν）ｙｉ,ν为未知的污染参数。本文用污染数据给出了β的最小一乘估计,并证明了它的渐近正态性和相合性。     

对称迭层矩形板的平面应力分析

常用的对称迭层板为各向异性板．根据平面应力问题的基本方程精确地用应力函数解法求得了各向异性板的一般解析解．推导出平面内应力和位移的一般公式,其中积分常数由边界条件来决定．一般解包括三角函数和双曲函数组成的解,它能满足4个边为任意边界条件的问题．还有代数多项式解,它能满足4个角的边界条件．因此一般解可用以求解任意边界条件下的平面应力问题．以4边承受均匀法向和切向载荷以及非均匀法向载荷的对称迭层方板为例,进行了计算和分析．     

[100]金刚石薄膜的辐照响应特性研究

采用热丝辅助化学气相沉积(HFCVD)方法生长得到25μm厚的[100]取向金刚石膜,用以制备辐射探测器.在100 V偏压下,测得暗电流为16.1 nA,55Fe X射线(5.9 keV)和241Am α粒子(5.5 MeV)辐照下的净光电流分别为15.9nA和7.0nA.光电流随时间的变化先快速增加随后由于"pumping"效应逐渐达到稳定.X射线和α粒子辐照下的平均电荷收集效率分别为45;和19;,并由Hecht理论计算得到对应的电荷收集距离为11.25μm和4.75μm.     

半导体薄膜材料外延生长的蒙特卡罗模拟

半导体自组织生长量子点是一种新型半导体材料,它在纳米电子学、光电子学和生命科学中有广泛的应用前景,本文讨论了计算机模拟量子点的生长在材料设计中的重要意义,建立动力学蒙特卡罗二维模型, 通过获得的原子沉积的表面图样和对原子簇大小分布的数学统计,得到提高生长温度或者降低沉积速率等量子点外延生长的优化条件.     

薄膜厚度对MOCVD法沉积ZnO透明导电薄膜的影响

本文研究了薄膜厚度对MOCVD技术制备未掺杂ZnO薄膜的微观结构和电学特性影响.XRD和SEM的研究结果表明,随着薄膜厚度的增加,ZnO薄膜(110)峰趋于择优取向,且晶粒逐渐长大,薄膜从球状和细长棒状演变为具有类金字塔绒面结构特征的ZnO薄膜;Hall测量表明,较厚的ZnO薄膜有助于提高薄膜电学特性,可归于晶粒长大和晶体质量提高.40min沉积时间(膜厚为1250nm)制备出的ZnO薄膜具有明显绒面结构,其晶粒尺寸为300～500nm,电阻率为7.9×10-3Ω·cm,迁移率为26.8cm2/Vs.     

Localization of s-Wave and Quantum Effective Potential of a Quasi-free Particle with Position-Dependent Mass

The properties of the 8-wave for a quasl-free partide with position-dependent mass （PDM） have been discussed in details. Differed from the system with constant mass in which the localization of the s-wave for the free quantum particle around the origin only occurs in two dimensions, the quasi-free particle with PDM can experience attractive forces in D dimensions except D = 1 when its mass function satisfies some conditions. The effective mass of a particle varying with its position can induce effective interaction, which may be attractive in some cases. The analytical expressions of the eigenfunctions and the corresponding probability densities for the 8-waves of the two- and three-dimensional systems with a special PDM are given, and the existences of localization around the origin for these systems are shown.     

4,6-二甲氧基-2-[甲氧脲基硫代脲基]嘧啶的合成、晶体结构和理论计算

利用2-氨基-4,6-二甲氧基嘧啶在干燥条件下与硫氰酸钾、氯甲酸甲酯在乙酸乙酯溶液中反应制得4-(4,6-二甲氧基嘧啶-2-基)-3-硫代脲酸甲酯, 在二甲基甲酰胺溶液中培养出单晶, 通过X射线单晶结构分析法测定分子结构和晶体结构, 晶体属单斜晶系, 空间群为C2/m, 晶胞参数为: a＝1.6672(3) nm, b＝0.66383(12) nm, c＝1.1617(2) nm, β＝109.275(2)°, V＝1.2136(4) nm³, D_c＝1.490 g/cm³, μ＝0.281 mm^－1, F(000)＝568, Z＝4, R₁＝0.0341, wR₂＝0.1042. 运用Gaussian 03程序, 在6-311G的基组水平上, 用HF, MP2以及B3LYP三种计算方法对标题化合物进行了几何全优化, 并对其成键情况及自然键轨道(NBO)进行了分析.     

共振散射相关光谱一种新的单颗粒探测方法

基于共焦构型构建了共振散射相关光谱新方法, 阐明了共振散射相关光谱的原理, 并利用纳米金的共振散射特性, 将纳米金标记到生物分子上. 考察了该系统的重现性以及溶液粘度、粒径、浓度和激光能量对金纳米粒子在溶液中扩散行为的影响. 结果表明, 共振散射相关光谱可以替代荧光相关光谱, 应用于生物分析和某些生物系统研究.