动态化学腐蚀法制备大锥角近场光纤探针

基于液压传递原理,设计出一种用动态化学腐蚀法制备大锥角近场光纤探针的装置.实验结果表明,在传统的化学腐蚀法制备光纤探针的过程中,通过控制腐蚀液液面的上升速度,可以有效地控制探针针尖的形状以及锥角的大小.在此基础上,还论述了分步控制光纤与腐蚀液液面的相对位移的方法在大锥角光纤探针的制备中所具有的独特优越性.利用所制备的大锥角近场光纤探针在扫描近场光学显微镜上对直径为200nm的小球进行探测,其力学像证实该探针具有较高的形貌分辨率(约为50nm). 关键词： 动态化学腐蚀法 大锥角 近场光纤探针     

12MeV直线感应加速器二极管优化设计研究

 本文用MAGIC程序对设计的多种12MV直线感应加速器的二极管结构进行模拟计算,得出了二极管阴极表面电场强度分布,并根据实验研究结果,得到了结构最佳设计的二极管模型;随后利用扫描电镜方法对不同天鹅绒的结构进行了分析与发射性能实验研究。最后得到优化后的二极管产生的电子束束流参数为发射束流I_e=8.50kA,传输束流I₈=3.0kA ,打靶束流I₀=2.30kA。     

胞嘧啶、胸腺嘧啶在银胶体系中的傅里叶变换表面增强拉曼散射

胞嘧啶、胸腺嘧啶在银胶体系中的傅里叶变换表面增强拉曼散射胡凤霞，李勤，林书煌，张崇起（首都师范大学综合所，首都师范大学物理系，首都师范大学综合所，北京１０００３７）ＦｏｕｒｉｅｒＴｒａｎｓｆｏｒｍＳｕｒｆａｃｅ－ＥｎｈａｎｃｅｄＲａｍａｎＳｐｅｃｔｒ...     

用Nd：YAG1064nm激发的FT－SERS技术研究鸟嘌呤分子

用Ｎｄ：ＹＡＧ１０６４ｎｍ激发的ＦＴ－ＳＥＲＳ技术研究鸟嘌呤分子张崇起，胡凤霞，李勤（首都师范大学物理系，都师范大学综合所，都师范大学物理系北京１０００３７）ＮＩＲ－ＦＴ－ＳＥＲＳｏｆＧｕａｎｉｎｅｉｎＳｉｌｖｅｒＣｏｌｌｏｉｄｓ￥ＺｈａｎｇＣｈｏｎ...     

Spot size diagnostics for flash radiographic X-ray sources at LAPA

Spot size is one of the parameters to characterize the performance of a radiographic X-ray source. It determines the degree of blurring due to magnification directly. In recent years, a variety of measurement methods have been used to diagnose X-ray spot size at Laboratory of Accelerator Physics and Application (LAPA). Computer simulations and experiments showed that using a rolled-edge to measure the spot size are more accurate, and the intensity distribution of X-ray source was obtained by a device with a square aperture. Experimental and simulation results on a flash X-ray source at our laboratory are presented and discussed in this paper. In addition, a new method for time resolved diagnostics of X-ray spot size is introduced too.     

神龙二号多脉冲X射线剂量测量

神龙二号加速器可以产生三个脉冲宽度约80 ns(FWHM)、脉冲间隔约500 ns的X射线,为了获得每个脉冲X射线剂量,采用康普顿探测器和热释光剂量计相结合的方法进行测量。针对神龙二号加速器X射线能谱分布,采用MCNP程序优化设计康普顿探测器,测量多脉冲X射线信号,获得每个脉冲的剂量比例,应用热释光剂量计测量多脉冲X射线总剂量,由总剂量和剂量比例准确得到每个脉冲X射线剂量,实现神龙二号加速器多脉冲X射线剂量测量。     

SURFACE-ENHANCED RAMAN SCATTERING STUDY ON NON-ACTIVITY OF Ag-Cl CLUSTERS

The non-active mechanism of Ag-Cl clusters in surface-enhanced Raman scattering (SERS) was discussed on the basis of the study of the interaction and adsorption competition of chlorions with a series of compounds: benzoic acid, p-hydroxybenzoic acid, and m-hydroxybenzoic acid on silver surface. As a result of the addition of chlorions, the SERS signals of these molecules were sharply and rapidly reduced and quenched in intensity. The change of Raman bands at 1644 cm^-1 for benzoic acid, and at 1636 cm^-1 for p-hydroxybenzoic acid and m-hydroxybenzoic acid, before and after the addition of chlorions, indicated the desorption process of these adsorbed molecules, and the adsorption behavior of the molecules remaining adsorbed on the silver surface.     

一种实用的多功能的函数拟合程序

研制了函数拟合程序.本程序主要特点在于可键盘或联机输入实验数据.利用计算机图示功能,手动、或自动拟合,以寻求最佳。本系统能打印出拟合后各参数的最佳值。并能在数字绘图仪上分别画出实验数据和理论曲线或光谱分解后的各分立子谱带。