稀土元素镧,铽,镱在雏鸡中的分布及其生物效应

将不同剂量的Ｌａ、Ｔｂ和Ｙｂ的ＥＤＴＡ络合物注入种蛋，研究了育成雏鸡的畸变和稀土在脏器组织中的分布，提出胚胎对稀土敏感。     

X射线光学进展

Ｘ射线光学的发展，有利于Ｘ射线分析技术的进一步发展，进而提高人们的认识水平。本从Ｘ射线光源、光学元件和应用领域几方面来概述Ｘ射线光学的最新进展。     

Design and properties analysis of multi-layer dielectric used in pulse compressor gratings

Used in chirped-pulse amplification system and based on multi-layer thin film stack, pulse compressor gratings (PCG) are etched by ion-beam and holographic techniques. Diffraction efficiency and laser-induced damage threshold rely on the structural parameters of gratings. On the other hand, they depend greatly on the design of multi-layer. A theoretic design is given for dielectric multi-layer, which is exposed at 413.1 nm and used at 1053 nm. The influences of coating design on optical characters are described in detail. The analysis shows that a coating stack of H3L (H2L)9H0.5L2.01H meets the specifications of PCG well. And there is good agreement of transmission between experimental and the theoretic design.     

Convergence in L space for the homogenization problems of elliptic and parabolic equations in the plane

We study the convergence rate of an asymptotic expansion for the elliptic and parabolic operators with rapidly oscillating coefficients. First we propose homogenized expansions which are convolution forms of Green function and given force term of elliptic equation. Then, using local L^p-theory, the growth rate of the perturbation of Green function is found. From the representation of elliptic solution by Green function, we estimate the convergence rate in L^p space of the homogenized expansions to the exact solution. Finally, we consider L2(0,T:H1(Ω)) or L∞(Ω×(0,T)) convergence rate of the first order approximation for parabolic homogenization problems.     

有界随机噪声激励下一类非线性系统的共振与饱和现象

研究了二自由度非线性系统在有界随机噪声激励下,系统响应的共振与随机饱和现象。用多尺度法分离了系统的快变项,用线性化方法求出了系统响应幅值的一、二阶矩,并给出了系统优化设计的一些建议。数值模拟表明本文提出的方法是有效的。     

金属元素的正电子鉴别技术

测量了20种金属元素的符合多普勒展宽谱,并与理论计算的结果比较．CDB谱的高动量部分反映了正电子与核心电子的湮灭,由于核心电子在原子组成材料时仍然保留了元素特性,CDB谱的高动量部分可以用来鉴别元素．     

Surface states and its influence on luminescence in ZnS nanocrystallite

In this pape,r the influence of surface effects on the self-activated (SA) luminescence in ZnS nanoparticles prepared by the wet-chemical method is presented. It is observed that the luminescence of SA decreases dramatically by rinsing with methanol. In the rinsed sample, the luminescence of SA increases more by ultraviolet (UV) light irradiation. To clarify its origin, the Raman spectra and electron paramagnetic resonance (EPR) are studied. The results demonstrate that the vibrational modes assigned to organic functional groups of -OH and -COO and -CH₃ decreases remarkably by rinsing, while the EPR signal originated from the unpaired electrons of some transition metal impurity ions including Mn²⁺ increases. It is suggested that the SA centers prefer to occupy the sites near the surface and that the donor of SA emission may be partly related to the organic functional groups of -OH and -COO adsorbed on the surface. The surface-dangling bonds caused by unpaired electrons of some transition metal impurity ions play a role of surface states, leading to the quenching of the SA emissions. The organic functional groups chemically combine with these surface-dangling bonds leading to the decrease in surface states and surface nonradiative relaxation channels and to the increase in the SA emissions.     

Optimization of near-field optical field of multi-layer dielectric gratings for pulse compressor

Multi-layer dielectric (MLD) gratings for pulse compressors in high-energy laser systems should provide high diffraction efficiency as well as high laser induced damage thresholds (LIDT). Nonuniform optical near-field distribution is one of the important factors to limit their damage resistant capabilities. Electric field distributions in the gratings and multi-layer film region are analyzed by using Fourier modal method. Optimization of peak electric field in the gratings ridge is performed with a merit function, including both diffraction efficiency and electric field enhancement when the top layer material is HfO₂ and SiO₂, respectively. A set of optimized gratings parameters is obtained for each structure, which reduce the peak electric field within the gratings ridge to being respective 1.39 and 1.84 times the value of incident light respectively. Finally, we also discuss the effects of gratings refractive index, gratings sidewall angle and incident angle on peak electric field in the gratings ridge.     

涂层界面结合强度检测研究(Ⅱ)：涂层结合界面应力检测系统

利用X射线衍射技术(XRD)测试了涂层及其基体材料的应力及其变化规律，建立了一种涂层结合界面应力检测系统，进行界面结合状态的检测研究.利用涂层从基体脱粘前后的界面应力变化量，结合涂层材料的物性参数和涂层-基体系统温度场参数，用涂层残余应力衍射峰来表征涂层与基体的结合强度，创立一种研究检测涂层结合强度理论的实验新方法，适用于各种热障涂层的界面结合强度测量. 关键词： X射线衍射法(XRD) 界面结合强度 涂层 残余应力     

AlGaN/GaN异质结构中极化与势垒层掺杂对二维电子气的影响

从Ⅲ族氮化物中压电极化对应变弛豫度的依赖关系出发，通过自洽求解薛定谔方程和泊松方程,分别研究了自发极化、压电极化和AlGaN势垒层掺杂对AlxGa1-xN/GaN异质结构二维电子气的浓度、分布、面密度以及子带分布等性质的影响.结果表明：二维电子气性质强烈依赖于极化效应,不考虑AlGaN势垒层掺杂，当Al组分为0.3时，由极化导致的二维电子气浓度达1.6×10--13cm-2,其中压电极化对二维电子气贡献为0.7×10-13cm-2，略小于自发极化的贡献(0.9×10-13cm-2)，但为同一数量级，因而通过控制AlGaN层应变而改变极化对于提高二维电子气浓度至关重要. AlGaN势垒层掺杂对二维电子气的影响较弱, 当掺杂浓度从1×10-17增加到1×10-18cm-3时，二维电子气面密度增加0.2×10-13cm-2. 关键词： AlxGa1-xN/GaN 异质结构 二维电子气 自发极化 压电极化