1,4-萘醌的太赫兹,远红外及低频拉曼光谱研究

本文对1,4-萘醌进行了太赫兹时域光谱,远红外吸收光谱及低频拉曼散射谱的测试研究。1,4-萘醌的太赫兹吸收光谱与远红外谱仪测得的光谱取得了在1.75 THz(58.3 cm-1)/1.63 THz(54.3 cm-1)等处吸收峰位基本相同、两者相互佐证和补充的结果。将太赫兹和远红外吸收谱与低频拉曼散射谱进行比较,表明两种选择机制不同的光谱在1.04,1.72和4.59 THz等处的峰位基本重合,结合群论的不可约表示理论分析,表明该样品在低频波段具有拉曼活性和红外活性的振动属性(A1、B1或B2)。采用Gaussi-an03软件的密度泛函理论B3LYP函数和6-311基组模拟单分子红外与拉曼光谱,结合实验分析,对部分分子基团或原子振转模式给与了指认。     

Theory of sound field in a room

In the normal-mode theory of Morse, it gives a series of normal modes as the solution of forced vibration in a room. But actually there is always the direct radiation besides the normal modes which represent the reverbrant sound field only. The reason is that the normal modes were assumed only in the source, and naturally normal modes only are obtained in the solution. A theory of double source is proposed, that the sound source is both the source of the direct radiation as if in free space before the boundary surfaces were reached by the direct radiation, and after the first reflection from the boundary surfaces, the source of the reflected wavelets, randomly distributed both in space an in time on the boundary surfaces that build up the normal modes after further reflections. The wave equation is formed accordingly, and the solution of the wave equation, the sound field in a room, contains explicitly both the direct radiation and the reverberant sound formed of normal modes. The approximate mean square sound pressure is found to be the dircet sound determined by the sound power of the source,and reverberant sound determined by the sound power reduced by a factor of π/2, different slightly from the result obtained from energy consideration, if the source is pure tone. There is essentially no difference for a source of band noise.     

陕西师范大学物理学与信息技术学院2005年人才招聘

世界上的大多数物质都具有热胀冷缩的特性，但也存在着另一类物质，对它们加热时会发生热收缩现象．这类物质称为负热膨胀物质(negative thermal expansion，简称为NTE)．美国加州大学Santa Cruz分校的Z．Schlesinger教授所领导的研究组对此开展了工作，他们认为复合的振动模式导致了这类NTE物质的存在．     

Vibration properties of low-fraction hydrogen in deuterium ices

Inelastic incoherent neutron scattering spectra of D2O high-density amorphous （hda） ice, ice-Ⅷ and ice-Ⅱ mixed with small amount of H2O （（5%） have been measured recently on high-energy transfer spectrometer at Rutherford Appleton Laboratory （UK）. The hydrogen atom on D2O ice lattices has three distinguished vibrational modes, two bending at low frequencies and one stretching at high frequencies, and their frequencies are slightly different for different phases of ice. It was found that the lower one of the bending modes is located at -95 meⅤ for hda-ice, at -95 meⅤ for ice-Ⅷ and at -96 meⅤ for ice-Ⅱ and they are all lower than the value of 104 meⅤ for ice-Ih. It was also measured that the O-D and O-H covalent bond stretching modes of ice-Ⅷ are at -315 and -425 meⅤ, ice-Ⅱ at 307 and -415 meⅤ, hda-ice at 312 and -418 meⅤ, respectively. They are significantly higher than the values of ice-Ih at -299 and -406 meⅤ, respectively.     

Analysis of vibrational spectra of nano-bio molecules： Application to metalloporphrins

In this paper, we have applied the Lie algebraic model to nano-bio molecules to determine the vibrational spectra of different stretching and bending vibrational modes. The determined vibrational energy levels by the Lie algebraic model are compared with the experimental data. The results from the theoretical mode[ are consistent with the experimental data. The vibrational energy levels are clustering in the excited states.     

硅油的高压拉曼散射

利用金刚石对顶砧高压实验技术及红宝石荧光标压方法,研究了3种不同黏度的硅油(Silicone oil AP150 wacker,Baysilone oil M1000和Baysilone oil M30000)在室温条件下的高压拉曼散射光谱,实验最高压力为20 GPa.获得了硅油的不同拉曼振动模式在高压下的变化规律,发现Baysilone oil M1000和Baysilone oil M30000分别在0.47和0.31 GPa压力下发生分子结构或构型转变,使Si—O伸缩振动拉曼信号强度降低,并产生新的拉曼振动信号;Silicone oil AP 150 wacker,Baysilone oil M1000和Baysilone oil M30000分别在9,8和4.5 GPa压力下出现振动模式消失或振动频率随压力变化的斜率发生改变,表明具有不同结构和黏度的硅油在不同压力下内部结构发生了变化.     

Frequency Response of the Sample Vibration Mode in Scanning Probe Acoustic Microscope

Based on the interaction mechanism between tip and sample in the contact mode of a scanning probe acoustic microscope （SPAM）, an active mass of the sample is introduced in the mass-spring model. The tip motion and frequency response of the sample vibration mode in the SPAM are calculated by the Lagrange equation with dissipation function. For the silicon tip and glass assemblage in the SPAM the frequency response is simulated and it is in agreement with the experimental result. The living myoblast cells on the glass slide are imaged at resonance frequencies of the SPAM system, which are 20 kHz, 30 kHz and 120 kHz. It is shown that good contrast of SPAM images could be obtained when the system is operated at the resonance frequencies of the system in high and low-frequency regions.     

A2B模型的受迫振动模式研究的注记

讨论了A2B模型的受迫振动模式研究中的一些问题.     

HXD中XH拉伸振动的振动跃迁偶极矩方向的理论研究

本文利用局域模研究了“重轻”体系简单分子XH伸缩振动的实验振动光谱. 键偶极方法进一步为实验光谱分析提供了帮助(假设XH伸缩振动的跃迁偶极矩沿着XH键方向排列). 通过局域模和多维简正模对HOD,HND^-,HCD,HSD,HPD^-和HSiD的XH伸缩振动的理论计算, XH伸缩振动的局部1D图片可以用于分析跃迁偶极矩倾斜角度. 在HOD分子中,OH伸缩振动的跃迁偶极矩远离OH键并且向远离OD键的方向倾斜;在HSD,HND^-,HPD^-,HCD和HSiD分子中的XH伸缩振动远离OH键,但朝向OD键,表明键偶极近似法不能很好地适用于“重轻体系”分子,重原子X可以影响跃迁偶极矩方向. 利用分子中原子理论分析了偶极矩的变化.