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液晶空间光调制器能够方便地用于制作各种衍射型光学元件, 但液晶空间光调制器存在分辨率有限的缺点, 本文提出了用液晶空间光调制器制作相位型光栅, 产生一维和二维光阱阵列的新方案, 用迭代傅里叶级数算法优化设计光栅的相位分布, 在不改变空间光调制器硬件参数设置的情况下, 充分利用和发掘了空间光调制器的优点, 同时又能较好地回避其所存在的缺陷. 根据现有的空间光调制器的技术参数, 模拟仿真设计光栅, 计算光强分布, 结果表明: 用大失谐、小功率激光照明, 能够产生具有很高峰值光强和光强梯度的光阱阵列, 囚禁冷原子的光学偶极势达到mK量级, 对原子的作用力远大于原子的重力. 相似文献
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Ivan I. Stoikov Elena A. Yushkova Anastas A. Bukharaev Dmitry A. Biziaev Svetlana Yu. Selivanovskaya Mariya A. Chursina Igor S. Antipin Alexander I. Konovalov Ilya Zharov 《Journal of Physical Organic Chemistry》2012,25(12):1177-1185
The shape of supramolecular aggregates based on stereoisomers of p‐tert‐butyl thiacalix[4]arenes functionalized with secondary, tertiary amide and hydrazide groups at the lower rim in cone, partial cone and 1,3‐alternate conformations with several metal cations were investigated by atomic force microscopy. The examined p‐tert‐butyl thiacalix[4]arenes form host–guest complexes; dimers, spherics ellipsoids and elongated nanoscale particles depending on the conformation of macrocycles, the nature of the binding centers and the nature of the metal cation. Only associates formed by p‐tert‐butyl thiacalix[4]arenes with morpholide groups at the lower rim in cone conformation with silver cations exhibited a higher antimicrobial activity. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
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《Analytical letters》2012,45(8):569-574
Abstract Atomic absorption spectroscopy (AAS) has been demonstrated to be a metal-specific detector for chromium organometallic compounds separated by high pressure liquid chromatography (HPLC). Column effluent from the HPLC instrument was fed directly to the aspirator of the atomic absorption instrument set to record absorption due to chromium. Well defined peaks were obtained. In addition to being specific for a given metal, the method is free of some of the constrictions placed upon conventional ultraviolet absorption and refractive index detectors commonly used with HPLC. For example, solvents which absorb strongly in the ultraviolet may be employed and there is no need to use expensive spectroquality solvents. The method promises to be particularly useful for the analysis of specific organometallic compounds found in liquefied coal and shale oil. 相似文献
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《Analytical letters》2012,45(11):1767-1776
A TiO(OH)2 precipitate was used for the preconcentration of copper(II), zinc(II), and lead(II) in seawater prior to determination by flame atomic absorption spectrometry. The influence of pH, sample volume, amount of precipitate, and centrifugation time were optimized for quantitative recoveries of the analytes. Under the optimum conditions, the detection limits of copper(II), lead(II), and zinc(II) were 4.3, 9.7, and 9.6 micrograms per liter, respectively. The recoveries of analytes were between 95.00 and 103.00 percent with the relative standard deviation below 6 percent. The procedure was validated by the analysis of NASS-5 and SPS-WW1 Batch 109 standard reference materials and the procedure was successfully applied to seawater. 相似文献
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《Analytical letters》2012,45(4):745-752
Abstract An electrothermal atomization method of atomic absorption spectrometry using a platinum tube atomizer in air is described. The atomizer consists of 0.025 mm-walled platinum tube and two supports. The remarkable merit of the platinum atomizer is the stability in air, when heated. This paper describes the improved performance for volatile elements like alkalimetals. Detection limits and characteristic mass are calculated for 7 elements and compared with literature values. The platinum atomizer can be used with a simple, effective and relatively low-cost atomic absorption spectrometer for routine in situ analysis. 相似文献