一种简易的脑片图像的半自动区域划分及细胞计数方法

脑科学研究往往需要对实验动物不同脑区的分子表达、细胞数目及神经网络连接模式进行量化和比较分析,然而目前缺乏简便易行的规模化的脑区划分方法.本文基于Paxinos和Franklin的第二版小鼠图谱以及Photoshop和ImageJ等图像处理软件,发展了一种简易的脑片图像的半自动区域划分及细胞计数方法.首先,基于小鼠脑图谱可获得脑区划分所需的标准模版;然后,利用Photoshop软件对标准模版进行变形矫正,可实现小鼠脑切片图像的快速规模化半自动配准及区域分割;最后,利用ImageJ可实现对配准及分区后的脑片图像不同区域的半自动神经细胞计数和分析.此方法适用于脑片免疫组织化学分析、神经元分布模式检测和神经环路标记等研究,其操作简便、易于获取、并且不依赖于其他昂贵的商业化神经图像分析软件,能为条件有限的科研工作者提供极大便利.     

Conductivity effect in electrorheological fluids

Based on conduction model and cubic particle model, the relationship between current density and shear yield stress of electrorheological (ER) fluids was calculated and compared with some reported experimental results. The conductivity of the insulating oils is found to have been changed by the mixed particles. Several ways to decrease insulating liquid conductivity and increase the conductivity ratio of ER fluids have been proposed to prepare ER fluids with high shear yield stresses but low current densities.     

自聚焦透镜成像特征的仿真分析

自聚焦透镜是微小光学的主要研究对象,它所涉及的光纤成像计算和光路一般比较复杂,本文借助MATLAB程序对其成像过程进行演示分析,对于自聚焦透镜的设计和研究,以及光学类课程的教学均有直观作用.     

1550nm工作波长新颖结构细径偏振保持光纤的制备及性能研究

对工作波长在1550nm，新型结构细径偏振保持光纤的制备与性能进行研究，并制备出拍长达到2．1mm、消光比达到28dB（1km）、工作波长在1550nm、低衰减且高强度的细径偏振保持光纤．     

New Families of Rational Form Variable Separation Solutions to （2＋1）-Dimensional Dispersive Long Wave Equations

With the aid of symbolic computation system Maple, some families of new rational variable separation solutions of the （2＋1）-dimensional dispersive long wave equations are constructed by means of a function transformation, improved mapping approach, and variable separation approach, among which there are rational solitary wave solutions, periodic wave solutions and rational wave solutions.     

Microwave Magnetic Permeability of Fe3O4 Nanoparticles

Well-dispersed Fe3O4 nanoparticles are synthesized via an oxidization method with NANO2 as oxidant. The microwave magnetic properties of the composites are studied with different volume fractions of fe3O4 nanoparticles. It is found that a lower volume fraction corresponds to a higher magnetic resonance frequency. This could be ascribed to the enhancement of exchange interaction with a weakened dipolar interaction when the volume fraction decreases.     

First-Principles Study of Li Doping in a Double-Wall Carbon Nanotube

By performing first-principles calculations, we study Li doping in a double-wall carbon nanotube where a （5,0） tube is confined inside a （14,0） tube. There are three possible sites for Li doping and two of them are energetically favorable. The change of energy band structure is closely related to the doping sites and the charge transfer is investigated. Bader charge analysis indicates that Li prefers to donate its electron to the inner （5,0） tube. Moreover, the Li capacity of the system can reach LIC4.75 which makes it a promising candidate for Li-ion battery materials.     

磁光光纤光栅滤波器的全光时钟提取性能研究

研究了磁光耦合强度对磁光光纤布喇格光栅中模式转换光反射光谱特性的影响.根据磁光耦合模理论并结合光纤布喇格光栅的传播特性,数值分析了磁光光纤布喇格光栅的磁控特性,得到了3dB带宽可调的滤波器.采用级联磁光光纤布喇格光栅构造磁控梳状滤波器,实现了40Gbps归零数据信号的全光时钟提取仿真,分析了时钟信号的抖动性能与磁光耦合参量的关系.     

ZnO材料电子结构的第一性原理计算研究*

本文采用基于密度泛函理论的第一性原理平面波赝势法,研究了ZnO的纤锌矿结构、类石墨结构、闪锌矿结构和氯化钠结构的电子结构。结果表明：ZnO的纤锌矿结构是这四种结构中最稳定的结构;ZnO是一个离子性较强而共价键较弱的混合键金属氧化物半导体材料;ZnO的氯化钠结构是典型的间接带隙能带结构,其余均是直接带隙半导体能带结构。     

自由立体显示器上立体鼠标的实现及其应用研究

提出了一种在三维自由立体显示器的基础上,依据人眼双目视差的原理,使普通鼠标实现立体鼠标显现效果的方法.在此基础上,进一步提出了当立体鼠标指向屏幕上任意点时的实际位置深度信息的计算方法,并通过实验验证了该位置深度信息计算的正确性.理论分析和实验研究表明,提出的立体鼠标实现和位置计算方法可实现将当今的三维自由立体显示器应用于数字摄影测量系统.