邻菲咯啉荧光熄灭法测定铜

研究了在pH 6 2 5～ 7 5 5KH2 PO4 Na2 HPO4 缓冲介质中 ,铜与邻菲咯啉形成配合物而使荧光熄灭的实验条件 ,建立了荧光熄灭法测定微量铜的新方法。该方法的λex =2 6 6nm ,λem =36 8nm ,铜含量在 8～ 30 0ng·mL- 1 范围内 ,有良好的线性关系 ,相关系数r=0 9996 ,检出下限为 10 4ng·mL- 1 。用本法经巯基棉分离测定了环境水样中的微量铜。     

图像比色法在炉膛火焰温度场实时监测的研究

提出了一种基于比色测温原理 ,运用数字图像采集、处理技术和面阵CCD成像技术测量锅炉炉膛火焰温度场分布的监测系统。论述了该测温系统的测量原理和系统结构。通过实验给出了利用该系统测量所得的结果。实验结果表明 ,利用比色测量法可以计算出火焰温度场的瞬时分布 ,以此为依据可以判断锅炉燃烧的稳定性 ,并在异常情况下发出报警信号 ;采用双色信号对比的办法可以较好地消除环境及发射率的影响 ,有效地提高了测温精度     

Domain Investigation by the Conventional Bitter Pattern Technique with Digital Image Processing

In the cases of soft magnetic materials or complex domain configurations, investigations of the domain structure by the conventional Bitter pattern technique are generally difficult. It is demonstrated in this paper, referring to the examples of domain images of thin permalloy films and the basal surface of bulk cobalt single crystals, that this problem can be overcome by the application of digital image processing (DIP) system. In particular, the visibility limit in domain observation was expanded by an order of magnitude and high quality domain images could be obtained. Improvements over earlier results were achieved.     

Domain Wall Migration in 3-d in the Presence of Diffusing Impurities

A new three-dimensional simulation procedure was developed for domain wall (grain boundary, APB, magnetic, etc.) migration in the presence of diffusing impurities. The simulation is based upon a kinetic Monte Carlo algorithm and an extended Ising model, incorporating both conserved and non-conserved dynamics. The simulations show a dependence of the domain wall velocity on driving force which is very similar to that seen in 2-d and in qualitative agreement with experiment. That is, the presence of a low mobility regime at small driving force and an abrupt transition to a high mobility regime at larger forces, under some conditions, and a continuous, non-linear dependence of the velocity on the force in others. The main qualitative difference between the 2-d and 3-d simulation results is in how the domain wall roughness depends on driving force. The velocity-driving force relation is not consistent with classic continuum models, but may be described, in the high velocity regime, by a theory based upon a discrete version of these models.     

Simulation on the Effect of Brownian Motion on Nanoparticle Trajectories in a Pulsed Microplasma Cluster Source

We describe a simulation of the nanoparticle trajectories in a pulsed cluster beam source. Clusters, formed by condensation of atomic vapor in a helium bath, and considered here as rigid spheres having a diameter of 1.5nm, were tracked during their travel inside the source cavity, an aerodynamic lens, and a cylindrical nozzle. Steady state supersonic laminar flow of helium is considered in an axi-symmetric geometry aiming to simulate, within some limitations, the conditions under which cluster formation takes place in a pulsed microplasma cluster source. In spite of the unsteady nature of the pulsed source, the time scale characterizing particle motion in the flow field is significantly smaller than the characteristic time constant for the evolution of gas pressure in the source. For this reason, a steady simulation can shed some light on the understanding of processes governing nanoparticle motion in a pulsed vaporization source. The extent to which the Brownian diffusion can affect the particle extraction from the source is investigated. Simulations have shown that the Brownian motion perturbs the clusters from the trajectories dictated by the carrier gas and increases the rate of cluster deposition on the source internal walls. However, it does not hinder the aerodynamic focalization produced by the lens even in nano-size cluster regime. This result is qualitatively confirmed by experiment.     

新型AFM探针的制备及应用

采用熔拉 -腐蚀复合方法 ,将普通单模石英光纤制成直锥形光纤探针。利用自制工具将探针打弯 ,制成悬臂式光纤探针 ,在AFM上取得了较理想的测试结果。将自制光纤探针和商用硅材料探针获得的两种扫描图像进行了对比 ,分析了悬臂式光纤探针的特点     

快速计算阵列波导光栅波导耦合系数的修正重叠积分方法

提出了一种修正的重叠积分方法用以计算阵列波导光栅(AWG)波分复用器件中光从自由传输区域到阵列波导的耦合系数,并和光束传播法(BPM)数值方法计算得到的结果做了比较通过比较分析,得出结论:当波导中心距不是太小时,用修正重叠积分这一快速方法是合适的.     

阻尼型高斯-牛顿法及其在高频电磁波测井反演中的应用

提出一种改进的阻尼型高斯牛顿优化算法,通过引入阻尼矩阵,对反演参数依其相对修改量不同而给以不同的阻尼作用,并将它用于高频电磁波测井资料的反演中.     

多重网格法在非结构网格中的应用

将多重网格法运用于非结构网格.网格是通过聚合法得到的,网格之间是相互关联的.方程的求解采用Jamson的有限体积法.给出了二维、三维情况的数值算例.     

导体球壳上感应电荷及空间电场的分布(2)

本文利用镜象法讨论了在不接地导体球壳附近有点电荷时，空间的电场分布和球壳表面上感应电荷的分布。