Structural, Optical and Electrical Properties of ZnS/Porous Silicon Heterostructures

ZnS films are deposited by pulsed laser deposition on porous silicon （PS） substrates formed by electrochemical anodization of p-type （100） silicon wafer. Scanning electron microscope images reveal that the surface of ZnS films is unsmoothed, and there are some cracks in the ZnS films due to the roughness of the PS surface. The x-ray diffraction patterns show that the ZnS films on PS surface are grown in preferring orientation along cubic phase β-ZnS （111） direction. White light emission is obtained by combining the blue-green emission from ZnS films with the orange-red emission from PS layers. Based on the I-V characteristic, the ZnS/PS heterojunction exhibits the rectifying junction behaviour, and an ideality factor n is calculated to be 77 from the I-V plot.     

Electrostatic Instabilities at High Frequency in a Plasma Shock Front

New electrostatic instabilities in the plasma shock front are reported. These instabilities are driven by the electro- static field which is caused by charge separation and the parameter gradients in a plasma shock front. The linear analysis to the high frequency branch of electrostatic instabilities has been carried out and the dispersion relations are obtained numerically. There are unstable disturbing waves in both the parallel and perpendicular directions of shock propagation. The real frequencies of both unstable waves are similar to the electron electrostatic wave, and the unstable growth rate in the parallel direction is much greater than the one in the perpendicular direction. The dependence of growth rates on the electric field and parameter gradients is also presented.     

强流回旋加速器中心区模型试验装置上偏转板和中心区技术研究

中心区模型试验装置是进行强流回旋加速器关键技术研究的实验平台.本文介绍了为该试验装置所设计的偏转板和中心区,包括物理设计的考虑、数控加工技术及安装精度的控制技术.由于电磁场的相互作用粒子在偏转板中的的轨迹为螺旋线,其电极形状复杂,加工采用四轴联动以上的数控机床完成.为满足束流动力学的需要,中心区的电极结构比较复杂而且不规则,表面光洁度要求高,另外尺寸和安装位置精度要求严格.中心区曲面电极结构由三轴联动加工中心加工完成,中心区地电极与高频D板头部的电极间隙非常重要,在安装过程中,制作了专用的"电极间隙通止规"控制电极间隙精度在±0.05mm.     

“足三里”针刺镇痛效应外周传入神经纤维的分析

针刺“足三里”穴对以下颌运动反应为指标的痛模型具有显著的抑制效应,引起这一效应的,来自“足三里”穴的针刺镇痛冲动主要由腓神经中Aβγ传入纤维传递;足够数量的Aβγ纤维活动是产生显著镇痛效应的重要因素.传递镇痛冲动的Aβγ类粗纤维对传递致痛冲动的Aδ和C类细纤维的抑制作用,看来是针刺镇痛原理的一个组成部分。     

Spectroscopic manifestation of conical intersections of potential surfaces of triatomic systems

We have calculated the semiclassical shape of the absorption band for a triatomic complex of C_2V symmetry, corresponding to an electronic transition from the non-degenerate ground-state and two excited states A_i, B_i (i=1, 2) when there exists a point of accidental degeneracy A_i=B_i. The analysis is done assuming that two normal vibrations are excited, one of which is nontotally symmetric. A comparison is made with the band of the transition, characterizing optical absorption in Jahn-Teller systems.Translated from Teoreticheskaya i Éksperimental'naya Khimiya, Vol. 25, No. 3, pp. 337–339, May–June, 1989.     

考虑剪切变形的任意二次型双曲面扁壳的基本解

本文用Hrmander算子方法和平面波分解方法结合,推导出了计入剪切变形的任意二次型双曲面扁壳的基本解。它无论在理论上还是应用上都是很有意义的。     

基于外汇汇率的期权定价及其实证分析

在外汇汇率服从连续扩散过程模型下,研究了外汇汇率的几何平均亚式期权和附有汇率范围的示性函数的新型幂期权定价问题。在实证分析中,通过美元/人民币汇率的真实数据来计算以上所研究期权的价格,并和Black-Scholes模型下的期权定价进行比较,同时对相关期权的隐含波动率进行了分析。     

Sas_analyzer software for small-angle X-ray scattering data treatment

New approaches to the analysis of small-angle X-ray scattering data from nanoscale systems based on the optimization and direct multiple shooting methods are presented. A program is developed, which bears on these new approaches and allows a user to model small-angle X-ray diffraction data, introduce collimation corrections, and analyze dispersions in the samples. The program results for a number of typical nanosized systems (sols, catalysts) are reported and the comparison with currently available programs for small-angle data processing is presented.     

基于渐进核图割的SAR图像自动分割

合成孔径雷达(Synthetic Aperture Radar,SAR)图像是遥感目标检测与分割等研究的重要数据源。提出了一种渐进核图割分割方法,该方法通过迭代进行二类聚类分割,自动实现合成孔径雷达SAR图像中多目标的分割。实验结果表明,该方法能够有效地实现复杂场景SAR图像的多目标分割。