The Level-split of the Two-level Entangled Atom in an Optical Field

The behavior of a two-level entangled atom in an optical field with circular polarization is studied in this paper. The interaction of an optical field and one of the entangled atoms is analyzed in detail. A general solution of the SchrAo¨Gdinger equation about the motion of the entangled atom is obtained. The properties of the action are dependent on the initial state of the atom. By detecting the entangled atom out of the field, we can obtain the state of the other atom moving in the field. It is shown that the state of the atom out of the field will influence the energies of the split-levels of the atom in the field.     

非标准色传感器引起的颜色误差分析

本文推导了两种非标准色传感器在测色时引入的误差公式,并对其进行分析。最后通过计算8个样品的颜色对分析结果给于验证。     

Misalignment Fault Prediction of Wind Turbines Based on Improved Artificial Fish Swarm Algorithm

A misalignment fault is a kind of potential fault in double-fed wind turbines. The reasonable and effective fault prediction models are used to predict its development trend before serious faults occur, which can take measures to repair in advance and reduce human and material losses. In this paper, the Least Squares Support Vector Machine optimized by the Improved Artificial Fish Swarm Algorithm is used to predict the misalignment index of the experiment platform. The mixed features of time domain, frequency domain, and time-frequency domain indexes of vibration or stator current signals are the inputs of the Least Squares Support Vector Machine. The kurtosis of the same signals is the output of the model, and the 3σ principle of the normal distribution is adopted to set the warning line of misalignment fault. Compared with other optimization algorithms, the experimental results show that the proposed prediction model can predict the development trend of the misalignment index with the least prediction error.     

数字束流位置探测器通道自动增益校准方法的研究与实现

在现有硬件基础上,基于BPM测量准确度的需求,在自制的电子学FPGA芯片内,通过Verilog语言实现了一种数字BPM采样数据增益自动校准的设计。首先介绍了自动增益校准模块的系统总体设计;然后对模块的实现方法做了详细说明,设计并搭建了ADC数据自动增益校准测试平台以验证自动增益较准模块的功能;最后介绍了该设计在BPM通道标定中的应用。实验结果表明,该方法可以实现4通道增益一致,使ADC采样后的数据幅度相同,有效解决了由通道增益不一致引起的测量偏差,以及工程应用中ADC数据幅度校准工作量大且难于操作的问题,将在BPM系统通道自动标定中发挥重要作用。     

Pure single line oscillation of HF lasers in fine atmospheric window

Applied Physics B - A correction to this paper has been published: https://doi.org/10.1007/s00340-021-07611-y     

Some remarks on X(6900)

The analysis of the LHCb data on \begin{document}$X(6900)$\end{document} found in the di-\begin{document}$J/\psi$\end{document} system was performed using a momentum-dependent Flatté-like parameterization. The use of the pole counting rule and spectral density function sum rule provides consistent evidence that both confining and molecular states are possible. Alternatively, the nature of \begin{document}$X(6900)$\end{document} cannot be distinguished if only the di-\begin{document}$J/\psi$\end{document} experimental data with current statistics are available. Nevertheless, we found that the lowest state in the di-\begin{document}$J/\psi$\end{document} system likely has the same quantum numbers as \begin{document}$X(6900)$\end{document}, and \begin{document}$X(6900)$\end{document} is probably not interpreted as a \begin{document}$J/\psi-\psi(2S)$\end{document} molecular state.     

EcoLens: visual analysis of ecological regions in urban contexts using traffic data

Journal of Visualization - The increasing availability of spatiotemporal data provides unprecedented opportunities for understanding the structure of an urban area in terms of people’s...     

一种新型高双折射光子晶体光纤特性研究

设计了一种高双折射高非线性光子晶体光纤, 采用全矢量有限元法研究了这种光纤的基模模场、双折射、非线性、有效模面积及色散特性. 数值研究发现, 减小孔间距Λ的大小, 在波长1550 nm 处, 该光纤可获得10^-2 数量级的双折射B, 比普通的椭圆保偏光纤高约两个数量级; 同时, 该光纤可获得42 W^-1·km^-1 的高非线性系数γ. 另外,分别在可见光和近红外波段出现了两个零色散波长, 在波长800–2000 nm 之间具有良好的色散平坦特性. 这种设计为获得高双折射高非线性超平坦色散光子晶体光纤提供了一种新的方法, 该光纤在偏振控制、非线性光学和色散控制方面具有广泛的应用前景. 关键词： 光子晶体光纤 高双折射 高非线性 有限元法     

基于超声分子束和普通充气的聚变等离子体密度反馈实验研究

本文介绍了全超导托卡马克装置EAST实验中等离子体密度反馈的方法和结果. EAST密度反馈采用普通充气 (gas puffing) 和超声分子束 (supersonic molecule beam injection, SMBI) 在放电过程中反馈进气, 获得稳定、预期的等离子体密度. 典型的一天放电实验中, 每次放电的充气量和壁滞留的变化可分为两个阶段: 第一阶段为初始约20次放电, 该阶段充气量非常高且呈指数趋势下降, 粒子滞留率为80%–90%, 壁滞留迅速上升. 第二阶段为随后的约50次放电, 该阶段充气量较小且保持稳定, 粒子滞留率为50%–70%, 壁滞留缓慢上升. SMBI的加料效率为15%–30%, 延迟时间小于5 ms. 因此使用SMBI 进行密度反馈效果优于gas puffing反馈, 相同条件下前者充气量较后者减少了～ 30%, 壁滞留减少了～ 40%, 再循环系数也相应减少. gas puffing反馈时, 采用脉宽调制模式效果优于脉幅调制模式. SMBI密度反馈可以作为未来EAST长脉冲高参数放电的主要手段之一. 关键词： 密度反馈 超声分子束 再循环 壁滞留     

不同衬底和CdCl2退火对磁控溅射CdS薄膜性能的影响

在科宁7059玻璃, FTO, ITO, AZO四种衬底上磁控溅射CdS薄膜, 并在CdCl₂+干燥空气380 ℃退火, 分别研究了不同衬底和退火工艺对CdS薄膜形貌、结构和光学性能的影响. 扫描电子显微镜形貌表明: 不同衬底原位溅射CdS薄膜的形貌不同, 退火后相应CdS薄膜的晶粒度和表面粗糙度明显增大. XRD衍射图谱表明: 不同衬底原位溅射和退火CdS薄膜均为六角相和立方相的混相结构, 退火前后科宁7059玻璃, FTO, AZO衬底上CdS薄膜有 H(002)/C(111) 最强衍射峰, ITO衬底原位溅射CdS薄膜没有明显的最强衍射峰, 退火后出现 H(002)/(111) 最强衍射峰. 紫外-可见分光光度计分析表明: AZO, FTO, ITO, 科宁7059玻璃衬底CdS薄膜的可见光平均透过率依次减小, 退火后相应衬底CdS薄膜的可见光平均透过率增大, 光学吸收系数降低; 退火显著增大了不同衬底CdS薄膜的光学带隙. 分析得出: 上述结果是由于不同衬底类型和退火工艺对CdS多晶薄膜的形貌、结构和带尾态掺杂浓度改变的结果. 关键词： CdS薄膜 磁控溅射 退火再结晶 带尾态