HIAF-SRing的等时性模式光学设计

高精度环形谱仪SRing作为HIAF装置的核心之一,是获取高品质放射性次级束,并将束流用于加速器技术研究、原子物理及核物理实验的关键设备。SRing有三种运行模式:等时性模式、正常模式与内靶模式。等时性模式下,SRing运行在特殊线性光学设置下,可以精确测量寿命低至几十微秒的原子核的质量。介绍SRing等时性模式的线性光学及高阶项校正的设计方案。在使用程序GICOSY进行等时性高阶项校正数值计算后,将得到的光学传输矩阵输入到程序MOCADI进行粒子跟踪模拟。以γ_t=1.43的等时性模式为例,SRing的动量接收度为±0.20%,粒子跟踪结果显示,在仅满足一阶等时性条件时SRing的质量分辨能力R=1.6×104。在保证动量接收度不变的前提下,考虑了等时性高阶项校正后SRing的质量分辨能力提高到R=1.2×106,达到设计要求。The Spectrometer Ring, as the most important experiment terminal of the High Intensity heavy-ion Accelerator Facility (HIAF) project, is a key device to obtain high-quality radioactive ion beams (RIBs) for atomic physics, nuclear physics experiments and accelerator technology researches. Three operation modes including the isochronous mode, the normal mode and the internal target mode, have been designed for the SRing. In the isochronous mode, the SRing operates under a special ion optics and could be used for precision mass measurement of short-lived nuclei with half-life shorter than several tens of microseconds. This study aims to design the ion optics for the isochronous mode and improve the mass resolving power of the SRing with higher-order ion-optical correction scheme for isochronism while preserve a large momentum acceptance of SRing. The ion optics and the higher-order correction for the isochronous mode are calculated with the code MAD-X and GICOSY respectively. Three ion optics with γ_t=1.43, 1.67, 1.83 settings have been calculated. The code MCOADI which utilizes the matrixes generated by the code GICOSY is used for particles tracking to verify the correction results. For the ion-optical setting of γ_t=1.43 with a momentum acceptance of ±0.20%, the mass resolving power of the SRing could be improved from R=1.6×104 to R=1.2×106, after isochronous higher-order corrections.     

生活用水的拉曼光谱分析

为了进行水质分析,运用激光拉曼光谱方法测量了自来水和白开水的拉曼光谱,分析了其振动方式归属与光谱强度。结果表明,3200～3400cm-1较强的拉曼谱带(伸缩振动)是水分子的振动拉曼特征峰,水中杂质尤其是钙镁离子含量是影响拉曼特征峰强度的主要因素。     

改善外腔半导体激光器调谐特性的新方法

基于原有的Littman结构外腔半导体激光器,提出采用一种新的光学方法来实现波长调谐。该方法采用了包含一个旋转楔形棱镜的“光杠杆”系统来降低调谐的机械要求,提高波长选择精度。通过选择不同的楔形棱镜顶角和光线入射角,机械要求可以降低1～2个数量级,波长选择精度也得到相同量级的提高。该方法使Littman结构外腔半导体激光器的调谐特性得到极大的改善,并大大降低了震动的敏感性。     

表面波电磁声换能器的设计

简要介绍了产生表面波的电磁声换能器（EMAT）的工作原理，设计，制作了收发分开的两种EMAT，并建立了实验测试系统、测量了信号和发射EMAT提离距离的关系曲线，研究了激励脉冲个数、接收线圈的匝数对换能器信号的影响等。     

利用绝热过程实现远距离量子纠缠

提出利用绝热过程实现远距离量子纠缠的方案.Λ型原子和经典场、单模腔场发生相互作用,系统的绝热演化在暗态中进行.利用这种绝热演化进行远距离原子、腔场纠缠,可有效地抑制原子的自发辐射噪声.     

Chaos Behaviour of Molecular Orbit

Based on Hfickel＇s molecular orbit theory, the chaos and bifurcation behaviour of a molecular orbit modelled by a nonfinear dynamic system is studied. The relationship between molecular orbit and its energy level in the nonlinear dynamic system is obtained.     

Influences of Annealing on Residual Stress and Structure of HfO2 Films

HfO2 films are deposited on BK7 glass substrates by electron beam evaporation. The influences of annealing between 100℃ and 400℃ on residual stresses and structures of HfO2 films are studied. It is found that little differences of spectra, residual stresses and structures are obtained after annealing at lower temperatures. After annealing at higher temperatures, the spectra shift to short wavelength, the residual stress increases with the increasing annealing temperature. At the same time, the crystallite size increases and interplanar distance decreases. The variations of optical spectra and residual stress correspond to the evolutions of structures induced by annealing.     

卡宾催化对亚甲基苯醌的不对称硼化反应的研究

使用商业化的手性三氮唑盐和联硼酸频哪醇酯[B₂(pin)₂],实现了N-杂环卡宾催化的对亚甲基苯醌的1,6-不对称硼加成反应.该反应条件温和,底物适用范围广,官能团耐受性好,且有良好的反应收率及对映选择性.值得注意的是,在无过渡金属存在下,即使催化剂用量降至底物的0.1 mol%,反应仍能保持高收率和高对映选择性.     

Directional Design of Materials Based on Multi-Objective Optimization: A Case Study of Two-Dimensional Thermoelectric SnSe

The directional design of functional materials with multi-objective constraints is a big challenge,in which performance and stability are determined by a complicated interconnection of different physical factors.We apply multi-objective optimization,based on the Pareto Efficiency and Particle-Swarm Optimization methods,to design new functional materials directionally.As a demonstration,we achieve the thermoelectric design of 2D SnSe materials via the above methods.We identify several novel metastable 2D SnSe structures with simultaneously lower free energy and better thermoelectric performance in their experimentally reported monolayer structures.We hope that the results of our work on the multi-objective Pareto Optimization method will represent a step forward in the integrative design of future multi-objective and multi-functional materials.     

可视化智能融合导航系统

本文以提高导航系统的精度、可靠性、智能化和可视化程度为目标，利用智能工程的思想与方法将信息融合、人工智能和可视化技术综合应用于多传感器组合导航系统中，提出了面向２１世纪控制与导航技术的新一代导航系统概念—可视化智能融合导航系统，并对其功能、组成及关键技术进行了研究。