超软X射线流气式正比计数管

介绍了一种用于测量183～933eV超软X射线的圆柱形、侧窗式、流气式正比计数管,工作气体是0.11MPa的P-10气体或氦气-丙烷混合气体。计数管内径为φ25mm,直径为φ0.3mm的入射窗是由厚度80～90μgcm~2聚乙烯甲醛制成的。该计数管的特点:(1)薄窗,对软X射线透过率高。(2)流气式,工作寿命长。(3)能量分辨率好。(4)计数率高(1×10~(14)个/s)。(5)可测能区宽(0.183～10keV)。(6)可以方便更换窗膜材料、厚度及窗口直径。近几年来该计数管已经为高强度低能X光源提供较好监测。     

256色模式下图形图像处理系统中对不规则区域的处理

概述了图形图像处理系统中关于不规则区域的基本算法，包括：区域填充，边界跟踪，边界标志，几何处理，区域分割等等．并且，根据２５６色模式的特殊性，对传统的算法做了有针对性的改进，加快了处理速度，使其更适合于电影电视字幕、动画卡通人物等不规则图形图像区域．同时还给出了改进算法的程序设计的技巧．     

考虑处置效果的苯系物泄露应急方案生成方法

针对苯系物泄露次生突发环境事件的应急响应问题,研究了基于案例推理和处置效果的应急方案生成方法。首先,在计算案例相似度时,为避免历史案例不全产生的情景要素遗失,基于随机森林算法,结合专家知识构建了权重求解方法,采用案例检索方法得到相似案例集;然后,构建了应急处置效果评估指标体系,以全面评价相似案例对应的处置效果;进一步,考虑多专家评价可弥补决策者知识、经验等的不足,引入了自适应群共识调整算法,得到群体评价意见,通过集结相似度与处置效果,得到了方案的综合评价值并生成最优方案;最后,用算例说明了方法的可行性和有效性。     

Resolution enhancement with improved range Doppler algorithm in high numerical aperture OCT

The improved range Doppler algorithm is proposed to abate the trade-off between resolutions and depth of focus in spectral domain optical coherence tomography.By considering the finite beam width and the shape of the wavefronts produced by the Gaussian beam,a physical diffraction model is presented to simulate the light propagation process in the sample.The two-dimensional processing of the spectrum data is decomposed into two one-dimensional processings of Stolt transform and matched filter.Experimental results show that image reconstruction can be achieved.The transverse and axial resolutions are both improved significantly,especially in the out-of-focus range,and the resolutions are almost equivalent throughout the entire region of interest.     

Beam dynamics studies of the photo-injector in low-charge operation mode for the ERL test facility at IHEP

The energy recovery linac test facility （ERL-TF）, which is a compact ERL-FEL （free electron laser） two-purpose machine, was proposed at the Institute of High Energy Physics, Beijing. As one important component of the ERL-TF, the photo-injector that started with a photocathode direct-current gun has been designed. In this paper, optimization of the injector beam dynamics in low-charge operation mode is performed with iterative scans using Impact-T. In addition, the dependencies between the optimized beam quality and the initial offset at cathode and element parameters are, investigated. The tolerance of alignment and rotation errors is also analyzed.     

Solitons and intrinsic localized modes in a one-dimensional antiferromagnetic chain

By use of the Hartree approximation and the method of multiple scales, we investigate quantum solitons and intrinsic localized modes in a one-dimensional antiferromagnetic chain. It is shown that there exist solitons of two different quantum frequency bands: i.e., magnetic optical solitons and acoustic solitons. At the boundary of the Brillouin zone, these solitons become quantum intrinsic localized modes: their quantum eigenfrequencies are below the bottom of the harmonic optical frequency band and above the top of the harmonic acoustic frequency band.     

Persistent spin current in a quantum wire with weak Dresselhaus spin——orbit coupling

The spin current in a parabolically confined semiconductor heterojunction quantum wire with Dresselhaus spin--orbit coupling is theoretically studied by using the perturbation method. The formulae of the elements for linear and angular spin current densities are derived by using the recent definition for spin current based on spin continuity equation. It is found that the spin current in this Dresselhaus spin--orbit coupling quantum wire is antisymmetrical, which is different from that in Rashba model due to the difference in symmetry between these two models. Some numerical examples for the result are also demonstrated and discussed.     

Light induced microstructure transformation in a-Si：H films

A series of a-Si:H films are deposited by hot wire assisted microwave electron cyclotron resonant chemical vapour deposition (HW-MWECR-CVD), subsequently exposed under simulated illumination for three hours. This paper studies the microstructure change during illumination by Fourier Transformation Infrared (FTIR) spectra. There are two typical transformation tendencies of microstructure after illumination. It proposes a model of light induced structural change based on the experimental results. It is found that all samples follow the same mechanism during illumination, and intrinsic structure of samples affect the total H content.