共查询到20条相似文献,搜索用时 140 毫秒
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金属原子簇化合物的拉曼光谱研究李淑玲(地矿部岩矿测试研究所北京100037)任玲(北京理工大学化工与材料学院北京100081)RamanSpectroscopicStudyofMetalclusterConpoundsLiShuling(Instit... 相似文献
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相干反斯托克斯拉曼光谱(CARS) 和相干反斯托克斯超拉曼光谱(CAHRS)等高阶非线性光谱技术已经应用在动力学过程、基因表达谱筛选、高分辨率光谱分析等诸多领域。但因其涉及到的高阶微观极化率张量元数量众多,对其光谱信号进行定量分析非常困难。文献通过理论分析将CARS和CAHRS的微观极化率张量元分解为拉曼微观极化率张量元微分α′i′j′和超拉曼微观极化率张量元微分β′i′j′k′的乘积,将高阶光谱定量分析的困难简化为对低阶光谱的分析。该研究处理了具有C2v对称性分子基团,提出一种利用键极化加和模型及其实验修正的方法简化超拉曼微观极化率张量元微分β′i′j′k′比值的方案。首先利用键极化加和模型方法,在对C2v分子基团局域模式假设的基础上,进行单键的局域模式假设,通过对单键伸缩振动进行简正振动模式的分析,并与单键的偶极矩表达式进行比较,得到单键的超拉曼微观极化率张量元微分β′i′j′k′。在单键β′i′j′k′结果的基础上利用键极化加和模型,对C2v分子基团进行对称性分析,将基团中两个单键伸缩振动的β′i′j′k′耦合,得到C2v分子基团对称振动和反对称振动两种简正振动模式的超拉曼微观极化率张量元微分β′i′j′k′的表达式。在此基础上对C2v分子基团对称振动和反对称振动的β′i′j′k′表达式进行理论推导,结合对应振动模式下不同偏振组合的超拉曼退偏率ρHR-SS和ρHR-AS及HV偏振组合时实验测量的超拉曼光谱强度比,得到超拉曼实验修正的C2v分子基团β′i′j′k′之间的比值。再结合文献中拉曼实验修正的拉曼微观极化率张量元微分α′i′j′之间的比值,即可得到C2v分子基团CARS和CAHRS的微观极化率张量元之间的比例关系,为定量分析高阶非线性光谱信息提供理论基础。 相似文献
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针对长跨距密集波分复用系统中喇曼放大入纤泵浦功率过大的问题,将遥泵放大器(RP-EDFA)引入到系统中,通过对共纤RP-EDFA的噪音性能及其优化设计的研究,在理论上计算比较了RP-EDFA系统和后向喇曼放大系统在不同泵浦功率水平下的光信噪比和非线性相移,表明遥泵放大技术有效降低了入纤泵浦的功率水平,更适合长跨距应用.运用遥泵放大技术,对一个典型的长跨距系统进行系统Q值的模拟,结果表明:在 220 mW泵浦功率水平下可以实现跨距为 167 km的40×11.6 Gbit/s系统1000 km传输,Q值裕量4.4 dB. 相似文献
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High-resolution coherent anti-Stokes Raman spectroscopy (CARS) has been perfomed in hydrogen gas using a cw system. Accurate measurements of the Raman linewidths of the Q(0) through Q(3) transitions of molecular hydrogen have been made at pressures ranging from 0.75 to 40 atm at room temperature. The pressure-broadening coefficients determined for these lines are important in analytic and diagnostic applications of CARS in high-pressure media. 相似文献
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《中国物理快报》2017,(9)
We study the phonon mode excitation of spin-orbit(SO) coupled Bose-Einstein condensates trapped in a one-dimensional optical lattice. The sound speed of the system is obtained analytically. Softening of the phonon mode,i.e., the vanishing of sound speed, in the optical lattice is revealed. When the lattice is absent, the softening of phonon mode occurs only at the phase transition point, which is not influenced by the atomic interaction and Raman coupling when the SO coupling is strong. However, when the lattice is present, the softening of phonon modes can take place in a regime near the phase transition point. Particularly, the regime is widened as lattice strength and SO coupling increase or atomic interaction decreases. The suppression of sound speed by the lattice strongly depends on atomic interaction, Raman coupling, and SO coupling. Furthermore, we find that the sound speed in plane wave phase regime and zero-momentum phase regime behaves with very different characteristics as Raman coupling and SO coupling change. In zero-momentum phase regime, sound speed monotonically increases/decreases with Raman coupling/SO coupling, while in plane wave phase regime, sound speed can either increase or decrease with Raman coupling and SO coupling, which depends on atomic interaction. 相似文献
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在中药治疗过程中,以方剂为载体,注重整体,采用辨证论治的方法。为揭示方剂的药队规律,根据药队协同效应设计法,将活血化瘀汤方剂拆分为“调和”、“化瘀生新”、“活血止痛”、“补气”四个药队方剂。由于银纳米粒子可与煎剂产生强交互作用,并极大地增强拉曼信号,获取活血化瘀汤、调和药队煎剂、化瘀生新药队煎剂、活血止痛药队煎剂和补气药队煎剂五种方剂煎剂的表面增强拉曼散射(SERS)光谱,并对所有SERS谱峰进行归属。主要针对各煎剂中的18个拉曼信号(523,538,622,647,732,959,977,1 003,1 048,1 077,1 145,1 245,1 326,1 402,1 456,1 470,1 518和1 605 cm-1)进行讨论。活血化瘀汤SERS光谱中保留了药队煎剂的某些拉曼峰,如:538,622,647,732,959,1 003,1 048,1 326,1 402,1 456,1 470,1 518和1 605 cm-1。药队煎剂SERS光谱的某些拉曼峰并未在活血化瘀汤中出现,如:1 077,1 145和1 245 cm-1。在活血化瘀汤SERS光谱中,出现了新的拉曼峰,如:523和977 cm-1。新的拉曼峰出现说明新物质的产生。实验结果表明,活血化瘀汤所包含的药物成分并非是各药队煎剂所含药物成分的简单相加,SERS光谱可为方剂药队规律研究提供一优异、有效和准确的检测方法。 相似文献
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通过一种新开发的模拟计算方法,计算了硅酸钠熔体的拉曼谱,及其在高频区代表5种硅氧 四面体(用Qi表示,其中i表示桥氧数)的特征峰的拉曼散射系数Si,发现成分的变化对5 种Qi的特征峰的拉曼散射系数的影响非常小.在此基础上取平均分别得到:S0=1,S1=0 .514,S2=0242,S3=0090和S4=0015然后将计算得到的散射系数应用于二硅酸 钠熔体的实验谱图的定量分析中,得到了该熔体中硅氧四面体单元的分布.同时从计算与试 验谱图的定量解谱中发现,钠系硅酸盐熔体谱中Q0和Q2的ASS模所产生的散射信号 不容忽视.
关键词:
拉曼散射系数
硅氧四面体
硅酸盐熔体
高温拉曼谱 相似文献
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We investigate for the first time, to our knowledge, the enhancement of the stimulated Raman scattering in slow-light silicon-on-insulator (SOI) photonic crystal line defect waveguides. By applying the Bloch-Floquet formalism to the guided modes in a planar photonic crystal, we develop a formalism that relates the intensity of the downshifted Stokes signal to the pump intensity and the modal group velocities. The formalism is then applied to two prospective schemes for enhanced stimulated Raman generation in slow-light photonic crystal waveguides. The results demonstrate a maximum factor of 104(66,000) enhancement with respect to SOI channel waveguides. 相似文献
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We show that a liquid-hydrogen droplet can achieve high- Q values that exceed 10(9) for whispering-gallery modes in the ultraviolet. We show also that pumping high- Q liquid-hydrogen droplets with ultraviolet laser radiation generates many vibrational and rotational Raman sidebands that cover a broad spectral range from the ultraviolet to the near infrared. 相似文献