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精确的背景校正决定着冷原子吸收法检测痕量汞的检测下限,研究了基于普通汞灯光源的横向塞曼效应背景校正大气汞检测方法.汞灯光源253.65 nm共振谱线在磁场中垂直于磁场方向产生σ-,σ+和π三个线偏振光.利用超高分辨率光谱仪获取不同磁场强度下汞样品池对σ-,σ+和π线偏振光的吸光度,分析横向塞曼效应背景校正方法所需的最小磁场强度;在1.78 T强磁场强度下,分析了窄带吸收气体苯、宽带吸收气体丙酮对横向塞曼效应背景校正大气汞检测方法可能存在的干扰;利用σ-,σ+作为背景光,π线偏振光作为吸收光,对不同长度的饱和汞蒸气样品池测量,精确背景校正后,吸光度拟合曲线R值达到0.99.实验结果表明基于普通汞灯光源的横向塞曼效应背景校正大气汞检测方法可以实现精确背景校正,能够应用于大气环境痕量汞检测. 相似文献
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皮秒光脉冲在光纤中的传播特性测量 总被引:1,自引:0,他引:1
文章讨论了皮秒激光脉冲在单模光纤传输中光纤介质的色散及非线性折射率等效应对皮秒光信号的影响,利用时间相关单光子计数系统,观测了皮秒激光脉冲在单模光纤中的展宽及皮秒自聚焦现象,并对光纤中皮秒光脉冲的畸变进行了检测与研究。 相似文献
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在对于质子上的π~+光生过程作了一般考虑以后,我们从Mandelstam表示出发,进而采用Cini-Fubini近似,导出了关于π光生幅的同位标部分的公式。按照核子电磁结构的新数据,我们选取π-π作用的I=J=l共振的参数为t_r=22,α_v=1.52,b_v=1.60,计算了dσ/dΩ(90°),dσ_‖/dσ_⊥(90°)以及三个能量下的角分布。结果表明,在加入π-π作用之后,与实验之间的调合比之Chew等的结果有很大的改进,所定出的γ+π→π+π的耦合常数约为∧≈-2.8e,这与时行的结果大致相符。 相似文献
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基于分布函数理论,分析了Zeeman减速器中截止速度对蓝磁光阱装载的影响,研究了Zeeman减速器中截止速度与蓝磁光阱俘获原子数目之间的关系,对比了分布函数理论和通用理论两种模型的拟合结果,结果表明,分布函数理论模型能更好地描述两者之间的关系。利用多匝Zeeman减速器对进入蓝磁光阱的热原子束进行减速,制备了锶光钟的冷原子样品。在光钟系统研制中,利用分布函数理论对Zeeman减速器进行了优化设计,提高了Zeeman减速器的工作效率,为实现更高效更紧凑的Zeeman减速器及光钟小型化提供了参考。 相似文献
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背景磁场的精确标定对于原子钟的闭环运转以及不确定度评估有着重要的影响。在中性原子光晶格钟的不确定度的评估中,背景磁场引入的二阶Zeeman频移是重要的贡献项之一。本文提出利用自比对的方法,测量不同背景磁场条件下镱原子钟跃迁1S0→3P0两个π跃迁谱线对应的Zeeman分裂频率间距差值,得到Zeeman分裂频率间距差与相应背景磁场线圈电流的对应关系,最终标定出最小Zeeman分裂间距差在三个维度上对应的补偿磁场线圈驱动电流值。在此基础上,分别调节偏置磁场处于高低磁场强度条件下,测量了剩余背景磁场对钟跃迁频率产生的二阶Zeeman频移。结果显示二阶塞曼频移系数-0.0655(3) Hz/G2,对应的二阶Zeeman频移不确定度5.7×10-17。这项工作的开展为镱原子光晶格钟不确定度总体评估奠定了基础。 相似文献
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在对于质子上的π+光生过程作了一般考虑以后,我们从Mandelstam表示出发,进而采用Cini-Fubini近似,导出了关于π光生幅的同位标部分的公式。按照核子电磁结构的新数据,我们选取π-π作用的I=J=l共振的参数为tr=22,αv=1.52,bv=1.60,计算了(dσ)/(dΩ)(90°),(dσ‖)/(dσ⊥)(90°)以及三个能量下的角分布。结果表明,在加入π-π作用之后,与实验之间的调合比之Chew等的结果有很大的改进,所定出的γ+π→π+π的耦合常数约为∧≈-2.8e,这与时行的结果大致相符。 相似文献
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《Waves in Random and Complex Media》2013,23(2):109-117
Abstract We investigate the effect of a space-dependent random mass density field on small amplitude acoustic modes that are settled in a semi-infinite medium of a temperature growing linearly with depth. Using a perturbation method, the dispersion relation is derived in the form of Hill's determinant. Numerical solutions of this equation lead to the following conclusions: (a) a weak random field (with σeff?=?0.05) essentially affects long waves which experience attenuation and a frequency reduction; (b) for a stronger random field (with σeff?=?0.1), high-order sound modes behave as sound waves as they are attenuated and their frequencies are increased; (c) for a sufficiently strong random field (with σeff?=?0.2), mode coupling occurs, as a result of which the dispersive curves cross each other, the sound modes loose their identities, and some modes are amplified. Here σeff denotes the effective strength of a random field. 相似文献
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We demonstrate the generation of 10-microJ coherent extreme-ultraviolet (XUV) light at wavelengths from 73.6 to 42.6 nm, using high-order harmonics. The peak power of this coherent XUV light is estimated to be 0.13 GW at 62.3 nm, and the peak brightness achieved was 3x10(28) photons/(mm(2)mrad(2)s) . To our knowledge, this XUV energy is the highest value achieved with high-order harmonics. 相似文献
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MA Aiqun 《Chinese Journal of Lasers》1998,7(2):184-191
TheHigh┐orderSquezingofOrthonormalizationEigenstatesofa4MAAiqun(HarbinColege,Harbin,150020,China)MAZhimin(SuihuaTeachers'Col... 相似文献
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同步辐射光源中的高次谐波会使透射光栅衍射效率标定精度变差。为了校正光源中的高次谐波对透射光栅衍射效率标定的影响,提出了一种光源存在弱谐波情况下的透射光栅衍射效率标定方法,通过使用谐波X射线的衍射效率修正基波衍射效率标定中谐波的影响,从而得到更为准确的透射光栅衍射效率。使用该标定方法在北京同步辐射光源上开展了透射光栅相对衍射效率标定工作。实验结果表明:在100~800eV存在高次谐波能段,修正后透射光栅一级与零级的相对衍射效率与理论模拟结果吻合较好,修正后光栅二级与一级的相对衍射效率更接近理论模拟结果,但与理论模拟结果仍有较大偏差,该偏差主要来源光栅较弱的二级衍射。 相似文献
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现有基于热光源的关联成像主要是针对透射型物体,这样可简化关联成像分析过程。然而对于成像的实际应用,比如遥感技术,反射型物体将具有更大的实用价值。基于非相干均亮的热光源,对反射型物体的高阶关联成像进行了研究,推导出其高阶反射关联成像的关联函数、可见度及信噪比的解析式;对比二阶反射关联成像,讨论阶数对关联成像性能的影响。研究结果表明,对于反射型物体的关联成像,随着阶数的增加,成像的可见度得到提高,但信噪比下降,同时能够通过增加测量次数增加成像的信噪比。 相似文献
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Xiangmin Liu Pengfei Zhu Zonglin Yan Jiangwen Wu Qingfen Yang 《Optics Communications》2008,281(2):273-277
The accurate reflection coefficient of prism waveguide coupler that takes coherence property of incident light into account is obtained at first. Based on the reflection coefficient, the effect of coherence property of incident light on prism coupling is discussed in this work. It is shown that extra damping in waveguide caused by the coherence property is larger for high-order resonant mode than that for low-order mode. For 100 fs Gaussian pulses incidence, the reflected spectra at different resonant modes are obtained theoretically and experimentally, which show that coherence property has a strong effect on prism coupling at high-order modes. 相似文献
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B. Wende 《Zeitschrift für Physik A Hadrons and Nuclei》1967,206(1):1-17
Optical pumping on Cs133 atoms was performed by means of a new transmission technique. The cesium vapor was pumped towards equilibrium by an intensive circulary polarizedD 1 orD 2 light beam. A weakD 1 detecting beam was polarized alternately σ+, σ? and allowed one to measure continuously amount and sign of the absorption difference between σ+ and σ? light. The measured signals are proportional to the electron spin polarization. The new technique was used to investigate the influence of Cs buffer gas collisions on the pumping cycle and to measure the influence of radio frequency induced Zeeman transitions on the ground state polarization. In addition the variation of magnetic field and of pumping light intensity and polarization was studied. Some measurements demonstrate the high sensitivity of the applied method. The obtained qualitative results are discussed and further experiments are proposed. 相似文献
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U. Schlagheck 《Optics Communications》1975,13(3):273-275
We discuss the form of the electromagnetic constitutive equations for the boundary of gyrotropic materials. As an application we consider reflection of light at isotropic materials. It is shown that for Π- and σ-polarized incident light the ellipticity of the reflected light is determined by the optical rotatory power. 相似文献