罗丹明101染料的光谱特性研究

观测了罗丹明101染料在甲醇和酸性甲醇溶液巾的稳态吸收、稳态荧光和时间分辨荧光光谱,得到了吸收与荧光光谱的特征信息以及荧光寿命;通过拉曼光谱、红外光谱和密度泛函理论计算,对罗丹明101染料分子的振动模式进行了指认.研究结果全面系统地表征了罗丹明101染料的光谱特征以及分子结构和振动信息,为罗丹明101染料在染料敏化太阳能电池和生物荧光标记等方面的应用研究提供了依据.     

磁几何阻挫材料天然绿盐铜矿的中红外和拉曼光谱分析

在室温情况下,利用FTIR光谱仪测得了天然磁几何阻挫材料绿盐铜矿(Atacamite,β-Cu2 (OH)3Cl)的中红外光谱4 000～400 cm-1,同时还通过激光显微拉曼光谱仪获得了它的拉曼光谱4 000～95 cm-1.结合它的晶体结构参数,确认了官能团区4 000～2 500～1 000 cm-1和指纹区1...     

基于Ag纳米棒阵列的表面等离激元微型偏振器

采用静电近似理论计算了Ag纳米棒阵列在不同偏振光入射下的消光光谱。当入射光偏振方向平行于纳米棒长轴时会激发表面等离激元纵向振动模式,而当入射光偏振方向垂直于纳米棒长轴时会激发表面等离激元横向振动模式。基于两种模式共振波长的不同,采用Ag纳米棒阵列可以用来设计高性能的表面等离激元微型偏振器。Ag纳米棒阵列的偏振性能在纵向共振波长明显优于在横向共振波长,通过调节纳米棒的纵横比可以对纵向模式的共振峰位进行大范围调控。结果表明这种微型偏振器所适用的波长能够通过纳米棒的纵横比在可见到近红外波段范围内调控,而消光比和插入损耗能够通过纳米棒的直径和长度实现调控。     

Vibrational properties of cagelike diamondoid nitrogen at high pressure

Under high pressure, a cagelike diamondoid nitrogen structure was lately discovered by first-principles structure researches. This newly proposed structure is very unique and has not been observed in any other element. Using density-functional calculations, we study the pressure effect on its vibrational properties. The Born effective charges are calculated, and the resulting LO-TO splittings of certain infrared active modes are beyond 20 cm 1 . We depict the Γ -point vibrational modes and find the breathing mode, rotational mode, and shearing mode. Frequencies of all the optical modes increase with pressure increasing. Moreover, the relation between the breathing mode frequency and the nitrogen cage diameter is discussed in detail. Our calculation results give a deeper insight into the vibrational properties of the cagelike diamondoid nitrogen.     

Infrared Spectroscopic Investigations of J-aggregates of Protonated Tetraphenylporphine

Protonated tetraphenylporphine(H2TPP) J-aggregates were prepared by aggregation on the liquid-air interface,Using FTIR spectroscopy,the authors observed the infrared absorption spectra of H2TPP and its J-aggregates.The IR spectra of H2TPP J-aggregates show significant changes compared with that of H2TPP monomer.Intensity changes(e.g.,strong enhancement of the in-plane vibronic mode and weakening of the out-of-plane vibronic mode of phenyi and porphyrin skeletal) were interpreted on the basis of stacking effects.Observation of the same type of bands collapse into single band was explained by the increase in the symmetry of H2TPP molecules.And the new bands at 1635 and 3407 cm-1 indicate the aggregates containing a large amount of bound water.     

α-LiAlO2的固相合成及Raman光谱研究

用固相反应法制得α-LiAlO2样品，并首次得到该材料的Raman光谱。Raman光谱表明，在654cm^-1和426cm^-1处存在两个较强的Raman光谱峰。分别对应于Alg和Eg振动模式。与α-LiAlO2比较可知，α-LiAlO2的层间结合力相对于α-LiAlO2更弱，其层状属性更强。     

聚偏氟乙烯全反式分子链振动模式的研究

利用ab initio分子轨道计算,对β相聚偏氟乙烯(PVDF)的全反式分子链进行了结构优化,计算值和实验值基本符合,且发现C－C－C键角有两种不同的值,112.8°和113.3°.对该分子的频率进行了计算,得到了红外强度谱.在400～4 000 cm-1范围内,对30 μm厚的聚偏氟乙烯取向膜和取向极化膜进行了红外光谱的测量，红外吸收光谱和红外强度谱基本一致.把所有振动模式分成六个系列:系列Ⅰ（544～415 cm-1）,系列Ⅱ（913～792 cm-1）,系列Ⅲ（1 353～998 cm-1）,系列Ⅳ（1 458～1 361 cm-1）,系列Ⅴ和系列Ⅵ.其中只有系列Ⅲ能改变分子的电偶极矩,该系列振动模式和β相的PVDF的自发极化有着密切的关系.     

远红外光谱在催化领域的应用前景(英文)

中红外光谱是催化领域的重要技术之一,已被广泛应用于催化过程的研究,而远红外光谱(FIR)的应用相对而言并不成熟.FIR可用于分析催化过程中较低能量的振动模式,如氢键、芳烃骨架振动、重原子间的伸缩振动、气体分子的转动等,从而可弥补中红外光谱的应用.在本文中,我们综述了有关FIR在催化领域的应用,FIR可以用来表征金属有机化合物类、金属原子簇类、不同晶相的氧化铝等催化剂的结构.在研究气体在催化剂表面上的吸附过程中FIR展现出独特的优势:直接检测到气体(如CO)与不同类型载体(如MOx)的成键M–C,分析两者的相互作用强度,进而表征催化剂载体表面的性质.如CO在载体M-ZSM-5(M=Li,Na,K,Rb,Cs)上的吸附强度ν(M–C)和交换离子M的1/r2成正比(r是M的半径),且CO在ZnO上的吸附强度(ν(Zn–C)=215 cm–1)相对于在M-ZSM-5的吸附较强(ν(M–C)=85–150 cm–1),因ZnO载体的电负性较碱金属强,对于CO的吸附作用更强.另外原位FIR可通过分析金属物与多种底物的相互作用强度、反应过程中催化剂的结构、浓度的变化趋势等,为催化机理的分析提供理论支持.在最新的研究成果中,我们借助原位远红外光谱研究了多种金属氯化物催化葡萄糖异构化过程的机理,经分析得知活性最高的催化剂CrCl3与底物葡萄糖分子中的羰基、羟基、乙二醇等结构配位较弱,而与葡萄糖分子中的活性部位羟基乙醛结构作用较强.而其他的金属氯化物如VCl3和FeCl3不仅与羟基乙醛结构配位较强,与底物和产物分子中的羰基或羟基的作用也较强,这对于其选择性地异构化葡萄糖不利.综上所述远红外光谱在催化领域的应用展现了广阔的前景,我们期待远红外光谱在催化研究中得到更广泛的运用.     

Correlation Between Energy Transfer Rate and Atomization Energy of Some Trinitro Aromatic Explosive Molecules

运用密度泛函理论的b3p86/6-31G (d,p)方法计算三硝基芳香族分子苦味酸、TBN、TNT、TATNB、2,4,6-三硝基-间甲酚、2,4,6-三硝基-苯甲醛、2,4,6-三硝基-苯甲醛肟和2,4,6-三硝基-o-三苯酚的红外振动频率以及它们的原子化能. 计算并讨论了这些炸药分子的能量迁移率与原子化能的相关性,发现能量迁移率与原子化能有较好的线性相关性. 在具有十分相近结构和相近分子量的炸药分子之间,这种相关性要更好一些.     

Detecting magnetic field direction by a micro beam operating in different vibration modes

A new method to detect the magnetic field direction by using a silicon structure is presented in this paper. The structure includes a micro beam and an in-plane coil electrode. When the electrode under a magnetic field is applied with an alternating current, the micro beam is actuated under the effect of the Lorentz forces. Magnetic fields of different directions cause different vibration profiles. The direction of the magnetic field is obtained by measuring the vibration amplitudes of the micro beam, which is driven to work at first- and second-order resonant modes. A micro structure has been fabricated using the bulk micromachined silicon process. A laser Doppler vibrometer system is implemented to measure the vibration amplitudes. The experimental results show that the amplitude of the structure, which depends on the different modes, is a sine or cosine function of the angle of the magnetic field. It agrees well with the simulation result. Currently a resolution of 10° for the magnetic field direction measurement can be obtained using the detecting principle.