La(Ⅲ)与β-萘酚醛双核配合物的合成、表征及其与DNA的作用

合成了La(Ⅲ)与希夫碱β-丙氨酸缩β-萘酚醛(以KHL表示)双核配合物.通过元素分析,IR,UV,摩尔电导及热分析,确定配合物的组成为[La2(L)2(NO3)2]·2C2H6OH.采用荧光光谱法对其与DNA的作用进行了初步研究,结果表明随着配合物浓度的增加,对EB-DNA体系的荧光猝灭作用增强,配合物与DNA发生了类似于EB的较强的插入作用.     

VARIATIONAL STUDY ON MISSING BOND-CHARGE REPULSION ON THE EXTENDED HUBBARD MODEL: EFFECTS ON POLYACETYLENE

The variational approach is applied to the study on the effect of Coulomb interaction between electrons on the dimerization in a one-dimensional commensurability-two Peierls system, such as trans-polyacetylene. For the case of omitting direct repulsion between electrons in the bonds between sites W, it is confirmed that the weak interactions tend to enhance the dimerization; but when W is included, this enhancement will be attenuated. If |W| is sufficiently large, the net effect of electron-electron interactions will reduce the magnitude of the electron-phonon-induced dimerization.     

High-pressure-activated carbon tetrachloride decomposition

The pressure-induced molecular dissociation as one of the fundamental problems in physical sciences has aroused many theoretical and experimental studies. Here, using a newly developed particle swarm optimization algorithm, we investigate the high-pressure-induced molecular dissociation. The results show that the carbon tetrachloride （CC14） is unstable and dissociates into C2C16 and C12 under approximately 120 GPa and more. The dissociation is confirmed by the lattice dynamic calculations and electronic structure of the Pa3 structure with pressure evolution. The dissociation pressure is far larger than that in the case of high temperature, indicating that the temperature effectively reduces the activation barrier of the dissociation reaction of CC14. This research improves the understanding of the dissociation reactions of CC14 and other halogen compounds under high pressures.     

Sine-Gordon模型的重整化与相变行为

采用高斯波泛函方法，讨论了连续场论和格点化场论的Ｓｉｎｅ－Ｇｏｒｄｏｎ模型的基态性质和相变现象，分析比较了两种不同重整化方法结果的异同。     

A MBE ON-LINE OPTICAL MODULATION PHOTOREFLECTANCE ANALYSIS SYSTEM

An on-line optical modulation photoreflectance (PR) spectroscopy analysis system asso-cinted with the molecular beam epitaxy (MBE) system has been designed and established. This paper reports in detail the optical design, the experimental arrangement, and the adjust-ment of the system. GaAs film samples grown by MBE on Si-substrate have been measured with this on-line system. The results show that the on-line PR spectroscopy can characterize the quality of the as-grown film samples qualitatively and promptly.     

巧用示波器做音叉共鸣实验

示波器是一种用途十分广泛的电子测量仪器,它可以直接观察电信号的波形,测量电压的幅度、周期、频率等参数.在实际应用中凡是能转化为电压信号的电学量和非电学量如压力、温度、磁感应强度、光强等都可以用示波器来观测.共振是一种常见的自然现象,声音的共振通常叫做共鸣.为了让学生进一步加深对共鸣知识的理解和掌握,笔者在物理教学中增设了利用示波器观察共鸣现象的探究型实验供学生使用,取得了良好的教学效果.     

水的低频受激拉曼散射

利用532 nm的脉冲激光进行了水的受激拉曼散射研究. 水的低激发光能量下主要表现为受激Stocks和反Stocks 3426 cm^-1谱线; 在能量大于140 mJ时出现低频率313 cm^-1受激Stocks谱线, 同时出现后向3389和3268 cm^-1 的受激Stocks谱线. 实验结果表明, 在较强的激光作用下, 水的结构表现为冰的Ⅷ相.     

无源超高频RFID系统识别区域分析及优化

基于射频识别技术原理及射线跟踪理论,导出了实际环境中射频识别系统完整传播链路模型．提出基于目标区域识别率的系统性能评估方法,并讨论了其主要影响因素．结合电磁波传播理论及相干干扰抵消原理,提出标签集及相位开关目标区域识别率优化方法．在室内多径环境下,测试了采用标签集及相位开关优化方法的目标区域识别率．测试结果表明,两种方法下的系统目标区域识别率分别提高10％和7．6％．     

The stimulated Raman scattering competition between solute and solvent in Rhodamine B solution

The competition between the stimulated resonance Raman scattering(SRRS) of Rhodamine B(RhB) and the stimulated Raman scattering(SRS) of ethanol(C2H5OH) is observed at the RhB in C2H5OH solution.For different concentrations of the solution,the peak wavelengths of the SRRS,the amplified spontaneous emission(ASE),the fluorescence and the absorption of RhB are different.The SRRS of RhB and the SRS of C2H5OH are simultaneously generated when the concentration of the solution is 10 5 mol/L and the energy of the excitation laser is 20.4 mJ.Otherwise,only either the SRRS of RhB or the SRS of C2H5OH is generated.The SRRS can be amplified by the ASE gain when the SRRS is near the peak of the ASE,and the peak wavelength of the SRRS coincides with the wavelength of the maximal intensity ASE.     

外电场下的TCNQ电子转移过程研究

自制了紫外/拉曼两用的电化学薄层池。观测到了TCNQ在外电场作用下转变为TCNQ－而后又转变为TCNQ2－的紫外-可见吸收光谱变化的电子转移过程, 并且当有氧气存在时, TCNQ2－又被氧化而形成DCTC－的过程。还观测到了TCNQ在外电场作用下转变为TCNQ－的傅里叶变换拉曼光谱发生频移的电子转移过程。