拉曼光谱技术的发展及其在生物医学领域中的应用

拉曼光谱技术自发现以来广泛应用于检测固体和液体材料的化学成分,它可利用物质的光谱"指纹"信息,区分各种物质样品、检测不同生理状况的细胞及其中的生物分子,如核酸、蛋白质等.为探索拉曼光谱在生物医学领域的应用前景,在概述拉曼光谱原理的基础上,介绍拉曼光谱技术及其衍生出的其他技术,包括表面增强拉曼散射(SERS)、共振拉曼光谱(RRS)、相干反斯托克斯拉曼光谱(CARS)、受激拉曼光谱(SRS)技术等,最后对拉曼光谱的改进与应用提出展望.     

共焦显微拉曼在司法鉴定中甄别印章的应用

利用共焦显微拉曼光谱技术,以红外激光785 nm作激发光源,对几种不同品牌的印泥、印油和打印油分别做了拉曼光谱图.结果表明:印泥、印油含酯类物质,在拉曼光谱上有1 235 cm-1特征峰;彩色喷墨打印油含醇类物质,在拉曼光谱上有1 086 cm-1的特征峰.借此,可用拉曼光谱来区分印泥、印油与打印油.此外,不同品牌印泥、印油和打印油的拉曼光谱都有各自的特征峰,利用这些特征峰可以准确地辨别出印泥、印油的品牌或判断印章是否为伪造.共焦显微拉曼光谱技术为司法鉴定中如何鉴别文书中伪造印章,提供了一种快速、便捷、准确、无损的检测方法.     

氯苯的激光拉曼光谱研究

运用群论方法分析氯苯的振动模式,得到各振动模式的对称性和拉曼活性,结果表明,氯苯分子振动拉曼光谱具有30条频率不同的拉曼谱线.采用激光拉曼光谱学技术获得了氯苯的振动拉曼光谱,分析了氯苯拉曼光谱的特点,并对其中16条谱线进行指认,为有机混合物中氯苯分子的识别提供依据.     

富勒烯衍生物的拉曼光谱研究

利用近红外傅里叶变换拉曼光谱(1064nm)对4种C60衍生物进行了研究.实验结果显示,衍生物固体拉曼光谱中都包含了C60分子的特征拉曼峰,同时衍生物的拉曼光谱与C60拉曼光谱相比又有明显的不同,这主要是由于有机官能团的引入使得C60分子的结构发生了变化.通过对此现象的分析和解释,提出拉曼光谱分析是一种研究富勒烯衍生物的有效方法.     

拉曼光谱在玉石无损鉴别中的应用

通过对软玉及相似玉石蛇纹石玉、石英岩玉、大理岩玉、白色玻璃的拉曼光谱进行测试与研究,得到软玉具有由Si-O振动引起的特征拉曼位移672,930,1 057 cm~(-1);蛇纹石玉具有由Si-O振动引起的特征拉曼位移678 cm~(-1)和1 041 cm~(-1),由Mg-O引起的特征拉曼位移369 cm~(-1);石英岩玉具有由Si-O振动引起的特征拉曼位移460 cm~(-1);大理岩玉具有由CO_3~(2-)引起的特征拉曼位移1 080 cm~(-1);白色玻璃具有特征拉曼位移1 353 cm~(-1).根据拉曼位移的位置和强度,可无损、快速、有效地区分软玉、蛇纹石玉、石英岩玉、大理岩玉、白色玻璃.     

受激拉曼光谱系统的研制

拉曼光谱是一种包含丰富样品结构信息的光谱技术,但是拉曼光谱检测的缺点是检测灵敏度低和荧光干扰.本实验室研制的受激拉曼光谱系统,是将一束皮秒(10-12 s)脉宽的可见泵浦光和一束由飞秒(10-15 s)脉宽的探测白光共同作用于样品,产生受激拉曼信号.该光谱系统的拉曼泵浦光在可见和近紫外波段可连续调谐,可以同时获取受激拉曼光谱的增益和损失光谱,具有灵敏度高和抑制荧光干扰等优点.分别考察了拉曼泵浦光和拉曼探测光脉冲相对时序、拉曼泵浦光强度对受激拉曼光谱的影响,受激拉曼信号强度在拉曼泵浦和拉曼探测脉冲时间上完全重合时达到最大.在拉曼泵浦光强较小时,受激拉曼谱峰强度随泵浦光强度增大而增大;当拉曼泵浦光强度较大时,损失谱峰强度会趋于饱和,在研究的光强范围内增益谱峰会持续增长,未达到饱和.     

利用显微拉曼光谱检验激光打印机打印文件墨迹的研究

利用共聚焦显微拉曼光谱技术,分别对不同品牌、同一品牌不同型号及不同时间的激光打印机打印文件墨粉字迹的拉曼光谱进行研究,并探讨了非原装硒鼓对激光打印机打印文件拉曼光谱检验的影响。通过对激光打印机打印文件墨粉字迹拉曼光谱特征峰的位置、数目和相对强度进行分析,可以推断其墨粉成分的异同,为鉴别激光打印机打印文件提供一种快速、无损的检验方法。     

傅立叶变换红外光谱和拉曼光谱对参片的无损鉴别

利用傅立叶变换光谱和拉曼光谱法，直接、快速地测定了不同参片样品，并用计算机比对软件对所测样品的红外、拉曼光谱图进行比较．结果表明，不同品种、不同产地或加工方法不同的参片在高频区有相似的红外、拉曼特征光谱图，但在低频区其特征吸收峰位置和峰高有一定的差异，经计算机比对相关系数进行比较，不同参片的红外光谱图特别是拉曼光谱图仅有微小差别．傅立叶红外光谱技术和拉曼光谱技术用于鉴定分析人参，无需对样品进行分离、提纯，样品用量少，便于直接、快速、简便、有效进行测定。     

乙腈分子振动模式和振动光谱的群论方法研究

利用群论的方法可以在不解久期方程的情况下分析分子的振动光谱,本文运用群论方法分析了乙腈分子的简振振动模式,得到了各简振振动模式的对称性,根据振动拉曼光谱选择定则分析了乙腈分子各振动模式的拉曼活性,结果表明乙腈分子振动拉曼光谱有8条频率不同的拉曼谱线,并与实验测定的激光振动拉曼光谱进行比较,理论结果与实验结论吻合很好.     

食管肿瘤组织的拉曼光谱研究

使用显微拉曼光谱仪对30例食道肿瘤组织和食管正常组织进行了拉曼光谱检测,发现食道肿瘤组织的拉曼光谱在2932 cm-1和1650 cm-1附近出有明显的拉曼峰,而食管正常组织没有发现明显的拉曼峰.这些差异为利用拉曼光谱诊断食道肿瘤提供了实验依据.     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that