Kalman滤波法消除光谱连续背景的研究

本文研究了Ｋａｌｍａｎ滤波法消除光谱连续背景，以电感耦合等离子体原子发射光谱法测量氧化铽中Ｌａ，Ｅｒ，Ｇｄ，Ｄｙ，Ｄｕ和Ｔｍ为例研究了不同背景情况下的结果。用新息序列的平均平方和正交自相关系数超过出信度极限以外数为评价函数，可评价所估计的背景形状，是一种不用测背景，用计算方法消除光谱连续背景的好方法，本方法不仅适用于电感耦合等离子体原子发射光谱，对分光光度，原子等原则上都可适用。     

超声跟踪反常氯化亚汞声光器件的设计及性能分析

氯化亚汞（Hg₂Cl₂）单晶具有独特的声光特性,这使得Hg₂Cl₂声光器件-Bragg盒适用于各种光信号处理。本文以超声跟踪反常器件的设计思想为基础,得出了Hg₂Cl₂器件的设计参数,并分析了这类新型器件的性能。结果表明,该器件有良好的性能,特别是其体积比同类TeO₂器件小得多。这些优点使之可望成为二维声光信号处理系统的关键器件。     

PGNAA系统中D-T中子管的慢化装置优化设计

为了提高PGNAA系统中D-T中子管的中子慢化效率,获得更高的热中子产额,借助蒙特卡罗模拟,确定了以铅为中子反射层、5个聚乙烯层和铅层相互交替作为中子慢化层、碳化硼含量为3%的含硼聚乙烯作为中子吸收层以及铅作为γ屏蔽层的中子慢化装置模型。针对中子产额为3×107 n/s 的D-T中子管,该慢化装置输出面低于5 eV中子通量可达5.28×106 n/s,占总中子通量的30.8%,有效提高了中子慢化效率。经过验证模拟结果能够满足实验要求。To improve the moderating efficiency of D-T Neutron Generator in PGNAA system, and get higher thermal neutron yield, the Monte Carlo code MCNP was used to optimize the moderation setup. The lead was selected as neutron reflector and gamma absorber, 5 polyethylene layers and 4 lead layers constituted the neutron moderator and 3% boron-doping polyethylene was selected as neutron absorber. For the yield of 3107 n/s D-T Neutron Generator, this moderation setup can provide a yield of lower than 5 eV of 5.28106 n/s, accounting for 30.8% of total neutron yield, dramatically improves the moderating efficiency. It is proved that the simulation results can satisfy the requirement of PGNAA system by preliminary experimental verification.     

290 AMeV 12C诱发乳胶核反应末态粒子多重数关联

对290 AMeV 12C诱发乳胶核反应末态粒子间的多重数关联进行了研究。实验结果表明:黑径迹粒子、灰径迹粒子、重电离粒子多重数之间存在较强的关联,而且黑径迹粒子和重电离粒子多重数有饱和的趋势,这些特征与高能区实验结果一致;簇射粒子与其他粒子间的关联性较弱,这一特征与高能区实验结果不同,主要归因于弹核能量较低、簇射粒子产额较小;黑径迹粒子、灰径迹粒子在前后半球的平均多重数随靶核的增大而增加;实验结果可用基于碰撞几何的旁观体-反应体模型及级联蒸发模型来解释。We have investigated the multiplicity correlation of particles produced in 12C-emulsion interactions at 290 AMeV. It is found that there is a strong correlation between black track particle, grey track particle and heavily ionized track particle, and finally black track particles and heavily ionized track particles tend to saturation, which is the same as the experimental results observed at high energies. The multiplicity correlation between shower particle and other particles is weaker, which is different from the experimental results observed at high energies. This discriminating character can be explained by the lower energy of projectile. The productivity of shower particle is lower at intermediate energies compared to that at high energies. The forward-backward averaged multiplicity of black track particle and grey track particle increases with the increasing target size.     

A Scheme for Generating Entangled Squeezed States Based on Cavity QED

We propose a scheme for generating entangled squeezed vacuum states of electromagnetical fields. The scheme is based on cavity QED. In this scheme, an atom interacts, successively, with a classical field, two quantum cavity fields, and another classical field. By detecting the final states of the atom, the two quantum cavity fields will be projected to an entangled state.     

Induced Diffraction in Phase-Mismatched Second-Harmonic Generation

We show analytically that in phase-mismatched second-harmonic generation, an effective diffraction is induced at the second-harmonic （SH） frequency. Numerical simulation results agree with the analytical predictions. Compared to the case of linear propagation, the effect of the overall diffraction at the SH frequency becomes doubled due to the induced diffraction, which causes an interesting result that the SH beam width will be larger than that of the fundamental field.     

用于同步辐射光源的成像板粉末衍射系统

报道了我们研制的一套成像板粉末衍射装置,对其误差来源进行了详细的分析讨论,并与衍射仪进行了比较.该装置的半径为143.3mm,最大测量角度范围不160°，最大角度(2q )偏差小于0.03°,这些性能指标已被实验所证实,完全可应用于粉末衍射全谱的测量.     

CO+分子离子彗尾带系在近红外区域的光谱研究

CO 分子离子是一种重要的瞬态自由基分子,许多研究者对该带系进行了大量的研究。文章采用光外差-磁旋转-速度调制光谱技术测量了12C16O 分子离子彗尾带系(A2Πi-X2Σ )在近红外区域的3个支带(0,3),(1,4)和(3,6)的振转吸收光谱。利用最小二乘法拟合,得到了上态A2Πi(ν′=0,1,3)的精确的分子常数。进一步验证了光外差-磁旋转-速度调制光谱技术在吸收光谱测量中的优越性。     

食用坚果中铅含量的分析

采用原子吸收光谱法对食用坚果中污染元素铅的含量进行了分析。铅在0.00～2.00 μg·mL-1范围内具有线性关系,r=0.999 1,测定铅的RSD≤4.64%,标准加入法测定铅的回收率94.0%～102.0%,方法简单,结果准确。     

轮廓仪检测的系统误差分析

从轮廓仪的工作原理出发，分析了影响轮廓仪检测精度的主要系统误差，并以二次旋转非球面为例计算了系统误差对面形检测精度的影响，得出Talysurf轮廓仪在测量时，系统误差对面形误差的影响随顶点曲率的绝对值、口径以及偏心率函数的增大而增大，随定位误差和不重合误差的增大而增大的结论。最后的实验结果证明了该结论的正确性。