一种基于成像板的能量卡阈式快中子图像测量方法

为减小散射中子等较低能量的中子对快中子图像的贡献,提出了在成像板前依次紧贴金属卡阈片和富氢元素薄片的能量卡阈式快中子成像方法.该方法通过改变卡阈片材料、厚度等参数,可有效降低成像结构对某一能段中子的相对灵敏度.以14 MeV中子照相为例设计的能量卡阈式成像结构为TR成像板依次覆盖约150μm Pb膜和500μm聚乙烯膜,计算表明该结构对8 MeV以下快中子灵敏度小于其对14 MeV中子灵敏度的30%.利用K400加速器DT中子源开展了验证实验,结果表明能量卡阈式快中子成像结构能够有效消除样品散射中子引起的边界增强效应.     

铝丝阵等离子体K壳层辐射区域测量

采用球面云母晶体,在特定的几何布局下，通过选择适当的设计参数，在1.3 MA脉冲功率装置上获得了Ly线表征的Z箍缩铝丝阵等离子体K壳层辐射时间积分2维分布。与通常采用的带滤片卡域的时间积分针孔成像相比，避免了由于无法将测量能段准确设定在K壳层辐射谱线所在能区，而造成测量结果偏离真实的K壳层辐射分布的缺点，为模拟计算Z箍缩等离子体辐射输运程序提供了更为精确的校验参数。     

基于物距辅助的单站姿态处理方法

为了解决靶场姿态测量系统中远距离单站测量易出现不稳定解或解不收敛的难题,从而为靶场常规中远距离光学单站姿态处理提供可行方案,在某参与计算特征点物距可获取的前提下,提出了一种物距辅助的单站姿态信息获取方法;首先提出物面连续离散化等效计算像长的方法,在此基础上,以像长为匹配元素建立单站透视姿态测量模型,然后以炮管为例对算法进行试验验证,最后对关键影响因素进行误差分析。结果表明:偏航角、俯仰角相对真值的均方根误差分别为0.97°、0.90°;所提方法可拓展至飞机类非轴对称回转体目标单站飞行姿态的处理。     

Effective-field and Monte Carlo studies of mixed spin-2 and spin-1/2 Ising diamond chain

The magnetic properties of a mixed spin-2 and spin-1/2 ferromagnetic diamond chain are studied by effective-field theory and Monte Carlo(MC) simulation based on the Ising model.The temperature dependences of magnetization,magnetic susceptibility,internal energy,and specific heat are studied,respectively.The exchange interaction dependences of magnetization and the critical temperature are calculated by MC simulation.The changes of magnetization depending on the field increasing and then the field decreasing under steady-static conditions are also given.     

基于邻域总变分和边缘检测的遥感影像道路提取

针对道路提取的同物异谱和同谱异物难题,提出了一种基于邻域总变分和边缘检测的遥感影像道路提取方法,先对原始影像进行邻域总变分分割,提取出影像中具有均匀材质的地物,并采用Canny边缘检测方法获得原始影像的边缘数据;然后将边缘数据和分割结果融合,使均匀材质区域中的非道路地物和道路分离;最后采用多方向结构进一步提取狭长并具有一定宽度的道路.实验证明本文提出的道路提取方案能同时提取影像中光谱略有差异的道路,能有效剔除和道路黏连在一起的同谱异物地物,并能提取具有一定弯度的道路.     

ICP-AES在LiNbO3分析中的应用

微波溶样装置溶解样品,浓缩后,调整酸度,稀释,阳离子交换树脂分离基体铌,ICP-AES法测定LiNbO3晶体中Mg、Ca、V、Mn、Fe、Co、Ni、Cu、Zn、Cd等10种杂质元素.该方法的检出限达1μg/g,回收率在90%-110%之间,RSD＜5%.     

酸碱双点电位法测定盐酸环丙沙星的含量

本文采用酸碱双点电位滴定法测定盐酸环丙沙星含量。该法具有简便、快速、准确等特点。测定结果和药典法一致。     

Spatially-resolved spectroscopic diagnosing of aluminum wire array Z-pinch plasmas on QiangGuang-I facility

Spatially-resolved crystal spectrometers with a high spectral resolution are developed to diagnose K-shell x-ray radiation from Z-pinch plasmas. These diagnostic apparatuses are successfully applied to aluminum wire array Z-pinch experiments on QiangGuang-I facility, a driver with a pulsed current up to about 1.5 MA in 80 ns. Time-integrated experimental results show that the K-shell x-ray emission lines of aluminum Z-pinch plasmas are dominated by line emissions from helium-like ionisation state. Bright spots that might have higher electron temperature or density are produced randomly in location and size along the z-axis during implosions. According to the experimental data, the electron temperature and the ion density are estimated to be between 250 eV and 310 eV, and between 7.0×10¹⁹cm^-3 and 4.0×10¹⁹ cm^-3 respectively, while the ion temperature is inferred to be about 10.2 keV, which is much higher than the electron temperature.     

Z箍缩动态黑腔形成过程MULTI程序一维数值模拟

Z箍缩动态黑腔能够高效地将Z箍缩丝阵等离子体动能转换为黑腔辐射能,为驱动惯性约束靶丸聚变提供高品质的X射线辐射场.利用一维双温多群辐射磁流体力学程序MULTI-IFE,研究了"聚龙一号"装置驱动电流条件下的Z箍缩动态黑腔形成基本物理过程.数值模拟结果表明,在动态黑腔形成过程中,辐射热波的传播速度比冲击波的传播速度更快,比冲击波更早到达泡沫中心,使中心区域的泡沫在冲击波到达前就已具有较高的辐射温度.对于"聚龙一号"装置动态黑腔实验0180发次采用的负载参数,辐射热波和冲击波在泡沫中的传播速度分别约为36.1 cm/μs和17.6 cm/μs,黑腔辐射温度在黑腔形成初期约80 eV,在冲击波到达泡沫中心前可达100 eV以上,丝阵等离子体外表面发射的X射线能量集中在1000 eV以下.本文给出了程序采用的计算模型、美国"土星"装置丝阵内爆计算结果和"聚龙一号"装置动态黑腔实验0180发次模拟结果.     

Raman spectroscopy characterization of two-dimensional materials

Two-dimensional(2D) materials have become a hot study topic in recent years due to their outstanding electronic,optical, and thermal properties. The unique band structures of strong in-plane chemical bonds and weak out-of-plane van der Waals(vdW) interactions make 2D materials promising for nanodevices and various other applications. Raman spectroscopy is a powerful and non-destructive characterization tool to study the properties of 2D materials. In this work, we review the research on the characterization of 2D materials with Raman spectroscopy. In addition, we discuss the application of the Raman spectroscopy technique to semiconductors, superconductivity, photoelectricity, and thermoelectricity.