共查询到19条相似文献,搜索用时 93 毫秒
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铽-丙烯酸聚合物薄膜的制备和谱学性质 总被引:1,自引:0,他引:1
以键合方式制备了键合型稀土聚合物-铽-丙烯酸聚合物,通过三维荧光光谱确定了铽在丙烯酸聚合物中的最佳激发波长为306nm,最强发射波长为544nm,Tb-丙烯酸聚合物薄膜在306nm光激发下,产生Tb^3 的特征发射,归属于^5D4-^7FJ跃迁(J=6,5,4,3),其最大发射位于544nm,归属于Tb^3 的^5D4-^7F5跃迁,呈现强的绿色发射,说明丙烯酸的聚合没有影响Tb^3 的发光性质,而Tb^3 的参入也没有影响丙烯酸的透明性。通过发射光谱、激发光谱、中红外光谱、远红外光谱和拉曼光谱,研究了铽-丙烯酸聚合物薄膜的荧光性质和谱学性质。 相似文献
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木质素是自然界中第二丰富的天然聚合物,广泛存在于各种陆地植物的木质部中,利用木质素拉曼光谱对植物种类进行快速无损鉴别具有重要的应用价值。但由于木质素大分子构型非常复杂,对其拉曼特征光谱的仿真研究一直存在困难。利用Gaussian16W中包含的B3LYP密度泛函方法结合6-311G(d, p)基组,构建出三种木质素单体及其三种同种木质素单体构成的二聚体以及三种异种木质素单体构成的二聚体,提出了一种利用木质素的三种基本结构单体及其二聚体仿真分析木质素大分子拉曼光谱特征的方法。首先计算了三种单体的基本构型、轨道能级和电子空间分布,并分析了三种木质素单体拉曼光谱和振动模式的特点。随后利用不同组合方式的β-O-4二聚体的光谱谱峰特征,解释了特征谱峰信号位置漂移的成因,提出了判断木质素大分子信号特征的主要依据。研究结果表明,1 712 cm-1谱峰信号最强且位置稳定,振动归属为碳碳双键伸缩振动,该振动归属引起的特征峰可以作为木质素大分子最主要的信号特征;1 642 cm-1谱峰信号振动归属为芳香环骨架振动,仅受芳香环甲基数量影响产生劈裂,该振动归属引起的... 相似文献
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借助于表面增强共振拉曼光谱散射(SERRS)技术,研究了一种新型的偶氮聚合物材料侧链含咔唑与偶氮分散红共聚物(CAP)在化学沉积法制备的银膜表面的拉曼峰增强和吸附行为。实验结果显示,CAP在银表面的状态为: 聚合物通过咔唑单体中咔唑基团和偶氮单体中硝基与银膜衬底发生物理吸附,而聚合物的主链与衬底相距较远没有相互作用。可以推测,聚合物在衬底表面的这种状态将对偶氮光存储器件的稳定性和工作效率产生不良影响。 相似文献
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Two-beam coupling gain and speed of Cr-doped strontium barium niobate in the visible and near-infrared spectral regions are measured. It is found that the sample still exhibits the appreciable photorefractive gain in the near-infrared spectrum. Photorefractive parameters such as effective trap density, effective electrooptic coefficient and mobility · recombination-time product are obtained from the measurement. The photorefractive spectra of the coupling gain and speed in the sample are compared with those of Cr-doped KNSBN. 相似文献
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针对目前临床药物拉曼光谱的缺乏和药物检测领域的现状,利用拉曼光谱技术对抗生素、抗组织胺、血凝酶和止吐剂等几类常用临床药物进行了拉曼光谱的测量和研究。通过观测上述具有良好拉曼活性的药物样品拉曼光谱,不仅确定了样品拉曼峰的位移、强度和线宽,还探索了其包络的线形等光谱特性。通过分析和比较拉曼光谱图,找出各药物间的异同; 对于那些由于拉曼活性低或拉曼光谱的复杂样品,虽然暂时无法识别,但也进行了尝试性的测量或提出了测量建议。研究表明: 小分子药物的光谱特征很明显,拉曼峰分布较广, 对其进行光谱识别简单易行; 而大分子都表现出较弱的光谱特征峰, 常常伴随复杂的包络,不仅导致了对其光谱识别的困难, 也很难准确确定特征峰位置。对于不同药物,提出了用拉曼光谱测量和分析其药物成分的可行性,并通过分析其拉曼光谱的特性, 为医学工作者识别和分析药物成分提供了实验证据。不仅为建立药物的拉曼光谱数据库奠定了基础。还使业界看到了快速识别和检测药物的前景,从而促进拉曼光谱技术在药物检测上的运用。 相似文献
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S. K. Sudheer S. Prathibha D. Kothwala C. Engineer A. Raval A. B. Jerriwala H. Kotadia 《Journal of Raman spectroscopy : JRS》2010,41(4):363-369
Laser Raman spectroscopy is an effective tool for the study of biodegradable polymers, which play a vital role in the new developments in coronary implants such as stents. There is much excitement around the potential capabilities of synthetic biodegradable polymers and the effect they will have on the design and function of implanted devices. In the present investigation, heparin‐conjugated biodegradable copolymers were evaluated for their durability as drug‐eluting stent coatings. Laser Raman spectroscopic studies were carried out and spectra recorded and analyzed of explanted stents coated with different amounts of polymer alone, showing the existence of different levels at different quantities of polymer. The polymer was detected on every stent analyzed. On the stents coated with a thick layer of polymer, a firm layer of polymer still existed on the stent. In contrast, this layer was degraded and spread around on the stents coated with only a thin layer of the polymer. This indicates that the polymers used in the stents in the present investigation exhibit acceptable biodegradability. Such polymers can be used as efficient drug carriers, as these materials show good degradation after the stipulated period. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
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Lianlai Sun Xuan Luo Shufan Chen Yu Fang Qingjun Zhang Linhong Cao 《Journal of Macromolecular Science: Physics》2015,54(7):811-822
The optical properties of several carbazole-based photorefractive polymers which we prepared were determined. Through analysis of the UV-vis spectrum, the ratio of the azo nitrobenzene was adjusted to control the content of azo chromophore functional components. The solid transient fluorescence emission spectra of the photorefractive polymers were tested with a 325 nm emission wavelength. The results showed that the J-aggregates and several large closed-loop structures formed in the photorefractive polymers resulted in a long lifetime of their transient fluorescence. Spin-orbit coupling among the molecules increased the intersystem crossing rate, and induced delayed fluorescence. 相似文献
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The spectroscopic basis for extraterrestrial life‐detection through the molecular signatures of relevant biomaterials is dependent upon several instrumental facilities which could effect the diagnostic interpretation of key Raman bands from relevant substances occurring together in the geological record. To this effect, the Raman spectra of several polyaromatic hydrocarbons have been investigated under different conditions of spectral resolution using FT‐Raman‐spectroscopy operating at 1064 nm laser excitation wavelength. The observed Raman spectra are considerably altered under different conditions of spectral resolution; in particular, the discrimination between several polyaromatic hydrocarbons and beta‐carotene no longer becomes possible as the spectral resolution decreases. These results are relevant for the evaluation of miniaturised Raman spectrometers for space flight missions and incorporation into instrumentation for landers and rovers being proposed for future missions to Mars. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
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黑索金(RDX)是目前最为常用的军用炸药,随着新型战斗部的发展,异形的RDX药柱不断出现。为保证战斗部的作战效能,需要发展一种能够在线无损检测RDX药柱内部压力的方法。利用拉曼光谱测量表征RDX药柱的方法并结合第一性原理计算,确定了RDX的特征谱线,研究了拉曼特征谱线随外加压强的移动。在实验中分别测量了10,20和30MPa的样片,并通过15,25和35MPa的样片来验证拟合关系的偏差,发现RDX药柱的拉曼特征谱线的移动与外加压强的大小成很好的线性关系。这样就可以先在实验室标定RDX药柱拉曼特征谱线与外压强之间的线性关系,然后测量具有异形的RDX药柱的拉曼谱线,与标准样品的谱线比较得到谱线移动,根据标定得到的线性关系得到异形RDX药柱的内部压强,从而实现对黑索金内压的无损检测。实验表明该方法具有灵敏度高,一致性好的优点,目前该方法已经在某型战斗部的生产上进行试用。 相似文献