弱光紫外星模拟器的研制

为了解决月基紫外深空观测相机地面定标的难题,研制了一种动态范围大、星等模拟精度高的紫外星模拟器。该模拟器采用5 m离轴光管作为准直光学系统,用双积分球系统作为均匀光源,可模拟3～16等星的弱目标,其星等最小分辨率为0.2等星,星等不确定度为5.48%。通过试验证明,该星模拟器完全满足月基紫外弱光星等深空观测相机地面定标的试验要求,不仅可以在实验室内标定紫外观测相机的探测能力和灵敏度,还可用于测试观测相机的其它参数指标,为发展深空高轨探测相机提供了地面定标基础。     

弱光紫外星模拟器的研制

为了解决月基紫外深空观测相机地面定标的难题,研制了一种动态范围大、星等模拟精度高的紫外星模拟器。该模拟器采用5 m离轴光管作为准直光学系统,用双积分球系统作为均匀光源,可模拟3～16等星的弱目标,其星等最小分辨率为0.2等星,星等不确定度为5.48%。通过试验证明,该星模拟器完全满足月基紫外弱光星等深空观测相机地面定标的试验要求,不仅可以在实验室内标定紫外观测相机的探测能力和灵敏度,还可用于测试观测相机的其它参数指标,为发展深空高轨探测相机提供了地面定标基础。     

小视场长焦距镜头畸变高精度测量研究

利用由精密测角仪、显微摄像测量系统、微型双光栅平面干涉仪、平行光管以及星点组成畸变测量系统，对小视场长焦距的镜头进行畸变测量。在计算镜头畸变中，利用中心视场区域内畸变设计无穷小，采用三次多项式拟和的方法，计算镜头理论焦距；在边视场采用像高高次方和视场角正弦高次方加权平均的方法对测量偏差角进行修正，得到各视场的相对和绝对畸变。通过实际测量和计算验证，镜头全视场畸变测量精度可达到0.02%。     

HL－1电子密度行为在各种条件下的实验研究

在ＨＬ－１装置电子密度测量中，进一步改进了密度相移信号的处理方法。在氘放电、氦补充送气条件下得到了ＨＬ－１最高电子密度１０．８×１０１３ｃｍ－３。总结了密度在各种实验条件下的行为，并对各种实验条件对密度的影响进行了分析。     

多道HCN激光干涉仪在HL－1装置上的电子密度分布测量

本文描述了为测量ＨＬ－１装置电子密度分布而研制的多道远红外（ＦＩＲ）激光干涉仪系统及其特点。首次对装置在弹丸加料以及拉瓦尔（Ｌａｖａｌ）超声分子束注入实验条件下的等离子体电子密度时－空分布进行了观测和初步分析。同时，介绍一种处理密度相移信号的新方法。     

Electromagnetic Instabilities Excited by Electron Temperature Anisotropy

One-dimensional particle-in-cell simulations are performed to investigate the nonlinear evolution of electromagnetic instabilities excited by the electron temperature anisotropy in homogeneous plasmas with different parameters. The results show that the electron temperature anisotropy can excite the two right-hand electromagnetic instabilities, one has the frequency higher than Ωe, the other is the whistler instability with larger amplitude, and its frequency is below Ωe. Their dispersion relations are consistent with the prediction from the cold plasma theory. In the initial growth stage (prediction from linear theory), the frequency of the dominant mode (the mode whose amplitude is large enough) of the whistler wave almost does not change, but in the saturation stage the situation is different. In the case that the ratio of electron plasma frequency to cyclotron frequency is larger than 1, the frequency of the dominant mode of the whistler wave driRs from high to low continuously. However, for the case of the ratio smaller than 1, besides the original dominant mode of the whistler wave whose frequency is about 2.6ωe, another dominant mode whose frequency is about 1.55ωe also begins to be excited at definite time, and its amplitude increases with time until it exceeds the original dominant mode.     

微波密闭消解-电感耦合等离子体质谱法测定小鼠血浆中硒的含量北大核心CSCD

移取小鼠血浆样品100μL于消解罐中,加入5mL硝酸与2mL 30%(质量分数)过氧化氢溶液进行微波密闭消解,冷却后,将样品溶液赶酸至少于0.5mL,用水定容至25mL,以73 Ge为内标,选用标准检测模式(STD)。硒的线性范围为0.2~20μg·L^(-1),检出限(3s)为6.75μg·L^(-1)。加标回收率在93.1%~105%之间,测定值的相对标准偏差(n=6)小于5.0%。利用本方法测定补硒小鼠血浆中的硒含量,可观察到硒含量随给药时间而变化。     

Density and impurity profile behaviours in HL-2A tokamak with different gas fuelling methods

The electron density profile peaking and the impurity accumulation in the HL-2A tokamak plasma are observed when three kinds of fuelling methods are separately used at different fuelling particle locations.The density profile becomes more peaked when the line-averaged electron density approaches the Greenwald density limit n G and,consequently,impurity accumulation is often observed.A linear increase regime in the density range n e < 0.6n G and a saturation regime in n e > 0.6n G are obtained.There is no significant difference in achieved density peaking factor f ne between the supersonic molecular beam injection (SMBI) and gas puffing into the plasma main chamber.However,the achieved f ne is relatively low,in particular,in the case of density below 0.7n G,when the working gas is puffed into the divertor chamber.A discharge with a density as high as 1.2n G,i.e.n e=1.2n G,can be achieved by SMBI just after siliconization as a wall conditioning.The metallic impurities,such as iron and chromium,also increase remarkably when the impurity accumulation happens.The mechanism behind the density peaking and impurity accumulation is studied by investigating both the density peaking factor versus the effective collisionality and the radiation peaking versus density peaking.     

基于量子点的检测技术在法庭科学物证鉴定中的应用研究进展

由于具有独特的纳米尺寸效应和高灵敏度的光电效应,碳量子点以及半导体量子点技术已经被广泛应用于材料科学、生物和医药等领域。本文在简述量子点结构、合成方法等基础上,着重介绍了基于量子点的检测技术在法庭科学领域毒物、毒品和微量物证鉴定中的应用,旨在分析基于量子点的检测技术研究与应用现状,展望其在法庭科学领域中的应用前景。