表面增强拉曼光谱

章对拉曼光谱的原理进行了阐述．重点介绍了表面增强拉曼光谱(SERS)的实验特点和增强机制。指出目前普遍接受的观点是电磁增强机制和化学增强机制同时存在，只是两在不同实验体系中所占的比重不同。     

蒽醌分子的深紫外针尖增强拉曼散射的化学增强机制

利用含时密度泛函理论来研究深紫外针尖增强拉曼散射光谱的化学增强机制的报道,引发了许多关于紫外针尖增强拉曼散射的实验研究。本文通过含时密度泛函理论来计算铝3-蒽醌分子-铝3结在262 nm光能量激发下的拉曼光谱,结果表明该分子的拉曼光谱是针尖增强共振拉曼散射光谱,其化学增强因子为107。这表明在生物和材料领域,针尖增强共振拉曼散射技术可用于深紫外区域的指纹振荡光谱研究。     

单分子表面增强光谱

单分子表面增强光谱的研究不仅对揭示分子与金属纳米结构的相互作用的物理机制具有重要意义, 而且具有重要的应用前景. 本文主要结合我们在单分子表面增强拉曼散射方面的研究工作, 介绍了单分子表面增强拉曼散射的研究进展, 包括增强机理、与入射光偏振的关系、多颗粒体系中对拉曼散射光的偏振调控、单分子表面增强拉曼散射中的光学力问题及单分子表面增强拉曼散射的远程激发, 并简要介绍了单分子针尖增强拉曼散射和单分子表面增强荧光.     

结晶紫的表面增强拉曼光谱研究

本文通过测定结晶紫分子的普通拉曼光谱和表面增强拉曼光谱研究了结晶紫分子表面感应共振增强机制，认为共振增强源于结晶紫银溶胶体系中非键轨道能级的降低（吸收峰紫移）。     

空心银纳米球层层组装膜上对巯基苯胺的表面增强拉曼光谱研究

以对巯基苯胺(p-ATP)为探针分子,采用拉曼光谱研究了空心银纳米球与聚二烯丙基二甲基氯化铵(PDDA)层层组装做表面增强拉曼光谱基底的性质.实验结果表明:这种通过层层组装法制作的基底对p-ATP具有良好的增强效果;单层基底对p-ATP的不同振动模式的增强因子分别可以达到2×106和6×107.     

基于纳米材料拉曼增强特性的细胞氧化损伤检测

表面增强拉曼可作为单细胞氧化损伤的一种检测手段。以铜离子诱导的细胞氧化损伤为模型、以表面增强拉曼光谱为检测手段,建立了用以表征细胞损伤的拉曼光谱方法。通过制备经多肽修饰的金纳米花作为拉曼增强基底,使其能够进入细胞并达到信号增强的效果。利用CCK-8细胞毒性实验测试基底对细胞的损伤程度,确定基底质量浓度为160μg/mL。进一步利用CCK-8细胞毒性实验验证Cu²⁺对细胞的氧化损伤,证实经Cu²⁺诱导后细胞出现明显的损伤和死亡现象。最后,建立了Cu²⁺诱导的细胞氧化损伤模型,并获得不同条件下细胞所呈现的拉曼光谱,发现经氧化处理后,细胞受到不同程度的损伤,细胞内的糖类、核酸、脂质和蛋白质等物质均发生了一定程度的改变,对机体造成损伤。     

基于表面增强拉曼光谱分析水溶液中的泰乐菌素

高效液相色谱具有灵敏度高、精确度高和检出限低等优点,因此常被用来检测抗生素类物质;但是该法操作复杂、成本高、对实验人员有较高的要求。表面增强拉曼光谱(surface-enhanced Raman spectroscopy,SERS)克服了拉曼光谱灵敏度低的缺点,具备信息丰富、灵敏度高、准确度高、无需样品预处理、可现场探测等优点。因此实验使用暴沸法-柠檬酸钠还原硝酸银法制备银胶,采用表面增强拉曼光谱检测典型大环内酯类兽药抗生素泰乐菌素(tylosin,TYL)。在考察银胶制备条件对TYL拉曼光谱增强效果影响的基础上,利用最优条件下制备的银胶,考察银胶与待测样品混合比例对TYL拉曼光谱响应信号的影响;并在最佳的实验条件下,对TYL进行了定量分析。结果表明,制备银胶的最佳加热时间为25 min、最佳柠檬酸钠与硝酸银配置比为10∶1。银胶与TYL最佳的混合体积为5∶1。TYL浓度与拉曼信号强度具有较好的线性关系(y=0. 002 4x+4. 146 2,R2=0. 940 1),可以考虑用拉曼光谱定量分析水中的TYL。     

银镜衬底的表面增强拉曼散射机制研究

研究了不同粗糙度的银镜对不同分子的表面拉曼增强效应,实验结果表明：在吸附分子与银镜之间同时存在物理增强和化学增强两种机制,物理增强与银镜衬底的表面粗糙度有关;化学增强则与吸附分子的化学性质有关,总的增强效果因分子而异。     

几种水溶性Porphyrin在电化学处理的银表面上的表 …

利用波长为６３２．８ｎｍ激光激发的拉曼光谱仪，测定了三种水溶性ｐｏｒｐｈｙｒｉｎ在电化学粗糙银表面上的表面增强拉曼光谱。这些光谱非常相似，但也有一些重要的差别。实验还表明：当Ｓｎ（Ⅳ）ＴＭＰｙＰ（４）吸附在Ａｇ表面上时，Ｓｎ－Ｎ键仍稳定存在，而且吸附分子的表面浓度不同，其在表面的取向也不同。     

激光拉曼光谱及其应用进展

综述了近年来激光拉曼光谱的几种分析技术及其应用,涉及到的激光拉曼光谱有傅立叶变换拉曼光谱、表面增强拉曼光谱、激光共振拉曼光谱、高温激光拉曼光谱、激光拉曼显微及激光拉曼遥测技术等。     

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