用于电化学界面研究的共焦显微拉曼光谱技术(英文)

系统地介绍了将共焦显微拉曼光谱系统用于电化学界面研究的方法 ,包括铂电极的粗糙和电化学拉曼电解池的设计 .进行了铂上氢、氧和氯共吸附的拉曼光谱研究 .通过对甲醇氧化过程的现场跟踪 ,提出检测界面区溶液浓度变化和计算溶液 pH值的方法 .实验表明拉曼光谱技术可作为研究实际应用体系的重要工具 .     

钴电极在碱性溶液中氧化还原反应的现场共聚焦显微喇曼光谱研究

采用现场共聚焦显微喇曼光谱研究钴电极在碱性溶液中的氧化还原行为和生成物的喇曼光谱特征.研究结果表明:电位正向扫描时,在-0.64V左右Co氧化生成Co(OH)₂和CoO,随着电位正移逐步生成Co₃O₄,在正电位区电极表面层主要是Co₃O₄、CoOOH和CoO₂等;电位负向扫描时,电极表面上的高价含氧化合物相继还原为Co₃O₄和Co(OH)₂,并最终还原为Co.由不同电位下的生成物的喇曼光谱可以看出:电极表面上的氧化还原反应是随电位变化而逐步进行的连续化反应过程,并主要形成复合含氧化合物.     

The Active Oxygen Species for Oxidative Coupling of Methane over CeO_2/BaF_2 Catalyst by in Situ Confocal Microprobe Raman Spectroscopy

ＴｈｅＡｃｔｉｖｅＯｘｙｇｅｎＳｐｅｃｉｅｓｆｏｒＯｘｉｄａｔｉｖｅＣｏｕｐｌｉｎｇｏｆＭｅｔｈａｎｅｏｖｅｒＣｅＯ２／ＢａＦ２ＣａｔａｌｙｓｔｂｙｉｎＳｉｔｕＣｏｎｆｏｃａｌＭｉｃｒｏｐｒｏｂｅＲａｍａｎＳｐｅｃｔｒｏｓｃｏｐｙ＊＊Ｓｕｐｐｏｒｔｅ...     

Plasmonic Field Enhancement for Vibration Spectroscopy at Metal/Water Interfaces

Electrochemical (EC) reactions play vital roles in many disciplines, and its molecular-level understanding is highly desired, in particular under reactions. The vibration spectroscopy is a powerful in situ technique for chemical analysis, yet its application to EC reactions is hindered by the strong attenuation of infrared (IR) light in both electrodes and electrolytes. Here we demonstrate that by incorporating appropriate sub-wavelength plasmonic structures at the metal electrode, the IR field at the EC interface can be greatly enhanced via the excitation of surface plasmon. This scheme facilitates in situ vibrational spectroscopic studies, especially using the surface-specific sum-frequency generation technique.     

PCT纳米材料结构相变的变温拉曼光谱研究

采用溶胶－凝胶法制备了（Ｐｂ１－ｘＣａ）ＴｉＯ３（ＰＣＴ（ｘ）纳米晶粉和纳米薄膜,变温拉曼光谱显示ＰＣＴ（０）和ＰＣＴ（２０）从铁电四方相向顺电立方相的转变温度分别降低至４３０℃和３３０℃;结果同时表明ＰＣＴ（０）和ＰＣＴ（２０）薄膜的声子频率发生一定程度的红移或蓝移,这归因于纳米材料掺杂引起的诱导效应和晶粒尺寸效应。     

Flexible Metal Oxide Semiconductor Devices Made by Solution Methods

For the fabrication of next-generation flexible metal oxide devices, solution-based methods are considered as a promising approach because of their potential advantages, such as high-throughput, large-area scalability, low-cost processing, and easy control over the chemical composition. However, to obtain certain levels of electrical performance, a high process temperature is essential, which can significantly limit its application in flexible electronics. Therefore, this article discusses recent research conducted on developing low-temperature, solution-processed, flexible, metal oxide semiconductor devices, from a single thin-film transistor device to fully integrated circuits and systems. The main challenges of solution-processed metal oxide semiconductors are introduced. Recent advances in materials, processes, and semiconductor structures are then presented, followed by recent advances in electronic circuits and systems based on these semiconductors, including emerging flexible energy-harvesting devices for self-powered systems that integrate displays, sensors, data-storage units, and information processing functions.     

十六烷基三甲基溴化铵水溶液热致相变的红外光谱研究

在280～320K的温度范围内考察了30％十六烷基三甲基溴化铵水溶液的红外光谱随温度的变化。结果表明该体系的凝聚胶-液晶相转变温度为300K。在300K以下的凝聚胶相,分子的极性头部基团处于高度“固定”的状态,分子的碳氢链以有序的相互平行方式排列,极性头与碳氢链之间有一定的倾斜角。在300K以上的液晶相,极性头内部CH_3-(N~+)基团以及整个极性头与碳氢链之间发生了旋转,碳氢链变为以六方亚晶胞填充形式存在,旦扭曲式构象异构体数量显著增多,极性头与碳氢链之间已不存在倾斜角,分子的亲水极性头和疏水碳氢链部分都处于“融化”状态。     

固态磷脂相变行为的红外和拉曼光谱研究

用红外和拉曼光谱方法在２９０～４０５Ｋ的温度范围内考察了无水二肉豆蔻酰磷脂酰乙醇胺的分子构象随温度的变化。结果表明，该磷脂在３６５Ｋ附近的熔化相变过程中，不仅酰链的构象和堆积发生了有序－无序转变，而且极性头部基团和接界区域基团也发生了结构重排；逆相变过程中，烷基链构象重新恢复了有序，但头部基团和甘油骨架构象没有恢复原始有序状态。     

利用超额拉曼光谱研究硝酸镁水溶液中的离子对

利用超额拉曼光谱研究了室温下硝酸镁(Mg(NO₃)₂)溶液的离子缔合情况. 测量了该溶液羟基(－OH)伸 缩振动谱段和NO₃^-全对称伸缩振动谱段的拉曼光谱, 利用超额拉曼光谱及光谱拟合分析了这些光谱数据. － OH伸缩振动谱段的超额拉曼光谱显示, 低浓度(<2.3 mol·kg^-1)下阴离子第一水合层的水分子含量随溶液浓度 的升高呈线性关系增加, 在较高浓度时(>2.3 mol·kg^-1), 该含量变化偏离了线性关系, 这是因为Mg(NO₃)₂溶液 在高浓度时存在直接接触离子对导致的. 同样的转折点浓度也在对NO₃^- 全对称伸缩振动谱段的分析中被观测 到. 除了直接接触离子对, 还观测到三种溶剂分隔型离子对. 对该谱段下所有浓度的拉曼光谱和超额光谱进行 同时拟合, 给出了不同浓度下各种离子对的相对含量, 结果显示在0.23-4.86 mol·kg^-1浓度范围内都有溶剂分 隔型离子对和直接接触型离子对. 当Mg(NO₃)₂浓度低于2.3 mol·kg^-1时, 所有离子对的相对含量随浓度增加呈 现直线上升, 在高于这个浓度后直接接触离子对的相对含量急剧增加, 一种溶剂分隔型离子对的相对含量增加 变缓, 另一种溶剂分隔型离子对的相对含量逐渐减少, 还有一种溶剂分隔型离子对相对含量的增加趋势保持不 变, 在Mg(NO₃)₂浓度大于3.5 mol·kg^-1后, 其相对含量不再发生明显变化.     

Preliminary Study on Cordycepin-DNA Interaction by Raman Spectroscopy

The interaction of cordycepin with calf thymus DNA was investigated at physiological pH with drug/DNA molar ratio of 8. The Raman spectroscopy results indicated that the intercalation of high concentration cordycepin and the interaction of cordycepin with PO2 group led to a major reduction of B-form DNA structure in favor of A-form DNA.     

超高分子量聚乙烯凝胶／结晶膜中链缠结的Raman研究

为获得超高分子量聚乙烯的超高取向性，利用准稀溶液速冷解缠方法可使λｍ＝４００，力学性能大幅度提高，但距离链的理论强度还有一定差距，ＮＭＲ的相结合研究表明其中仍残存一定量的界面层及非晶部分。从缠经链角度来看，其分子链的解缠并不能达到完全。     

氯霉素包合物的拉曼光谱研究

通过拉曼光谱法研究氯霉素与β-环糊精相互作用形成包合物的过程,探讨拉曼光谱作为一种新的验证包合物形成方法的可行性.采用饱和水溶液法制备氯霉素包合物,共聚焦拉曼光谱仪分别检测氯霉素、β-环糊精、氯霉素与β环糊精的物理混合物、氯霉素包合物的拉曼光谱并对照分析.结果表明,拉曼光谱法可说明氯霉素的苯环结构和易水解基团二氯乙酰胺...     

氧化乐果的振动光谱及其表面增强拉曼散射研究

采用ATR-FTIR、FT-拉曼表征了氧化乐果在酸、碱、中性条件下的振动光谱,获得了氧化乐果分子较为全面的结构振动信息;以金/银核-壳粒子为基底,获得了不同浓度及其酸碱条件下氧化乐果的表面增强拉曼散射(SERS)光谱,考察了其分子在该基底表面的吸附状态及其酸碱影响,推测了氧化乐果的SERS机理;结果表明:νas(NH),νas(CH3),Amide Ⅰ,ν( POC ),ν( PO ),ν(C-S)为氧化乐果分子特征振动;中性条件下,氧化乐果浓度低于2.0×10-2 mol/L已无明显SERS,酸、碱条件下,在2.0×10-10 mol/L氧化乐果分子与基底的作用仍显著,尤其酸性的SERS更强;氧化乐果主要以磷酸酯结构与基底表面作用,探讨了酸碱条件下的不同水解历程对该作用的影响,为研究有机磷农药的形态变化提供了参考.     

Potential-Averaged Raman Spectroscopy for the Time-Resolved Study

Raman spectroscopy, especially surface enhanced Raman spectroscopy (SERS) has long been used to study the interfacial phenomena, it provides a possible method to characterize a variety of surface and interfacial processes at molecular levels in detail.     

The Quest for Polysulfides in Lithium–Sulfur Battery Electrolytes: An Operando Confocal Raman Spectroscopy Study

Confocal Raman spectra of a lithium–sulfur battery electrolyte are recorded operando in a depth‐of‐discharge resolved manner for an electrochemical cell with a realistic electrolyte/sulfur loading ratio. The evolution of various possible polysulfides is unambiguously identified by combining Raman spectroscopy data with DFT simulations.     

Study of Adsorption, Condensation, Orientation, and Reduction of Quinoline Molecules on a Pure Mercury Electrode Using Raman Microprobe Spectroscopy

Quinoline is known to adsorb on a mercury electrode surface with several differentorientations and it sometimes blocks other electrochemical reactions. The Ramanmicroprobe technique has been applied successfully to observe reorientations ofquinoline adsorbed on the mercury surface from neutral and basic aqueoussolutions. The orientation-distance profile from the mercury surface was also studied.A Raman band intensity of quinoline (1373 cm^–1) relative to the intensity ofperchlorate ion (931 cm^–1) was measured. The peak positions did not shift evenwhen the applied potential was altered, but the relative peak intensity changed.It was concluded that the adsorbed quinoline changes its orientation from a flatat –0.1 > E > –0.3V, to a standing at E < –0.5 V, passing through a mixtureof the two orientations when –0.3 > E > –0.5 V.     

表面增强拉曼光谱研究吸附态的变化

测量了吡啶分子在电化学处理的银表面和亚甲基蓝分子在硝酸刻蚀银表面的表面增强拉曼光谱（ＳＥＲＳ）．对ＳＥＲＳ谱线的分析结果表明，吡啶分子在较低的表面吸附分子密度时倾向于平躺方式；而在较高的表面分子密度时，则倾向于向垂直吸附态转化．亚甲基蓝分子在较低浓度时主要是平躺吸附，随Ｃｌ－浓度的增加，亚甲基蓝从“平躺”吸附态转向“站立”吸附态．     

新鲜乳腺癌组织的近红外拉曼光谱分析

采用便携式拉曼光谱仪对正常、良性和恶性的乳腺癌组织进行检测,通过对其拉曼光谱的指认,归纳了其主要区别和特征. 在3类乳腺组织中有明显的脂类的特征峰（1230,1268,1301,1440和1743 cm^-1）,而在良性和恶性的组织中,则出现了较为明显的蛋白（1246,1271,1315和1364 cm^-1）和核酸（1340 cm^-1）的特征峰. 良性和恶性组织的区别在于恶性组织特有的特征峰（1340 cm^-1）,而良性组织所特有的特征峰则应归属为蛋白. 在数据分析过程中,选择能够反映样本化学本质的特征峰,利用高斯过程的机器学习对特征峰值建立模型. 特异性（0.94）、灵敏度（0.95）和Matthews相关系数（0.86）表明在模型中3种组织有比较良好的辨别度,对于应用拉曼光谱方法辨别正常和患病乳腺组织具有参考价值.     

气相过渡金属钽和钇-碳链团簇的质谱研究

Nd:YAG产生的二倍频532nm激光消融金属靶表面,同时含有3%乙炔的氦载气喷向旋转的金属靶,通过等离子体反应形成中性的气相过度金属-碳链团簇分子。经过超声膨胀,由Skimmer形成准直的分子束,进入飞行时间质谱仪的电离区,被193nm的准分子激光电离。实验发现,钽奇数碳链的过渡金属钽团簇离子信号较小,而偶数碳链的团簇离子信号较大。钇碳链观察到了YCm+(m=1～4,6)、Y2Cn+(n=2,4,6)和YCnH2+(n=2～6)的离子信号。